Title of invention: One-way electrical steel sheet and its manufacturing method Technical field [0001] 　The present invention relates to a unidirectional electromagnetic steel sheet and a method for producing the same. 　The present application claims priority based on Japanese Patent Application No. 2018-052898 filed in Japan on March 20, 2018, the contents of which are incorporated herein by reference. Background technology [0002] 　The unidirectional electromagnetic steel sheet is made of a silicon steel sheet containing 7% by mass or less of Si, which is composed of crystal grains oriented in a {110} <001> orientation (hereinafter, Goss orientation) as a base material. The unidirectional electrical steel sheet is mainly used as an iron core material for a transformer. When a unidirectional electromagnetic steel plate is used as an iron core material for a transformer, that is, when steel plates are laminated as an iron core, it is essential to ensure insulation between layers (between the laminated steel plates). Therefore, in the unidirectional electromagnetic steel sheet, it is necessary to form a primary film (glass film) and a secondary film (insulating film) on the surface of the silicon steel sheet from the viewpoint of ensuring insulation. These glass film and insulating film also have the effect of applying tension to the silicon steel plate to improve the magnetic properties. [0003] 　The method for forming the glass film and the insulating film, and the general method for manufacturing the unidirectional electromagnetic steel sheet are as follows. A silicon steel slab containing 7% by mass or less of Si is hot-rolled and cold-rolled once or twice with intermediate annealing to finish the final plate thickness. Then, decarburization and primary recrystallization are performed by annealing in a moist hydrogen atmosphere (decarburization annealing). In decarburization annealing, an oxide film (Fe 2 SiO 4 or SiO 2 ) is formed on the surface of the steel sheet . Subsequently, an annealing separator mainly composed of MgO is applied to and dried on the decarburized annealing plate, and finish annealing is performed. Due to this finish annealing, secondary recrystallization occurs in the steel sheet, and the crystal orientation is oriented in the {110} <001> orientation. At the same time, on the surface of the steel sheet, MgO in the annealing separator reacts with the oxide film of decarburization annealing to form a glass film (Mg 2 SiO 4 or the like). An insulating film (phosphoric acid-based film) is formed by applying a coating liquid mainly composed of phosphate and baking it on the surface of the finished annealing plate, that is, on the surface of the glass film. [0004] 　The glass film is important for ensuring insulation, but its adhesion is greatly affected by various factors. In particular, when the thickness of the unidirectional electromagnetic steel sheet becomes thin, the iron loss, which is a magnetic characteristic, is improved, but it becomes difficult to secure the adhesion of the glass film. For this reason, in the unidirectional magnetic steel sheet, improvement of adhesion and stable control thereof are problems for the glass film. Since the glass film is caused by the oxide film produced by decarburization annealing, attempts have been made so far to improve the characteristics of the glass film by controlling the decarburization annealing conditions. [0005] 　For example, in Patent Document 1, the surface layer of a grain-oriented electrical steel sheet that has been cold-rolled to the final plate thickness is pickled before decarburization annealing to remove surface deposits and the surface layer of the ground steel. However, a technique is described in which the decarburization reaction and the oxide formation reaction proceed evenly to form a glass film having excellent adhesion. [0006] 　Further, Patent Documents 2 to 4 disclose a technique for improving film adhesion by allowing a glass film to reach a deep part of a steel sheet by imparting fine irregularities to the surface of the steel sheet by decarburization annealing. 　Further, Patent Documents 5 to 8 disclose techniques for improving the adhesion of the glass film by controlling the oxygen potential in the decarburized annealing atmosphere. These are technologies that promote the oxidation of decarburized annealed plates and promote the formation of glass films. [0007] 　Further technological development has progressed, and Patent Documents 9 to 11 focus on the temperature raising step of decarburization annealing, and improve the adhesion and magnetism of the glass film by controlling not only the atmosphere during temperature rise but also the temperature rising rate. Is disclosed. Prior art literature Patent documents [0008] Patent Document 1: Japanese Patent Application Laid-Open No. 50-71526 Patent Document 2: Japanese Patent Application Laid-Open No. 62-133021 Patent Document 3: Japanese Patent Application Laid-Open No. 63-7333 Patent Document 4: Japanese Patent Application Laid-Open No. Akira 63-310917 JP Patent Document 5: Japanese Patent Laid-Open 2-240216 discloses Patent Document 6: Japanese Patent Laid-Open 2-259017 discloses Patent Document 7: Japanese Unexamined Japanese Patent Application Laid-Open No. 6-33142 Patent Document 8: Japanese Japanese Patent Application Laid-Open No. 10-212526 Patent Document 9: Japanese Patent Application Laid-Open No. 11-61356 Patent Document 10: Japanese Patent Application Laid-Open No. 2000-204450 Patent Document 11: Japanese Patent Application Laid-Open No. 2003-27194 Non-patent literature [0009] Non-Patent Document 1: Toru Takayama, 2 outsiders, "Mineral phase evaluation of sintered ore for blast furnace raw materials by Rietveld analysis", Iron and Steel, Japan Steel Association, Vol. 103 (2017), No. 6, p. 397-40, DOI: 10.2355 / tetsutohagane. TETSU-2016-069 Outline of the invention Problems to be solved by the invention [0010] 　However, since the techniques described in Patent Documents 1 to 4 require an increase in the number of steps in the process, the operational load is large, and further improvement has been desired. 　Further, in the techniques described in Patent Documents 5 to 8, although the adhesion of the glass film is improved, the secondary recrystallization may become unstable and the magnetic characteristics (magnetism) may be deteriorated. [0011] 　Further, although the techniques described in Patent Documents 9 to 11 improve the magnetism, the film improvement is still insufficient. In particular, a material having a plate thickness of less than 0.23 mm (hereinafter referred to as a thin material) does not have sufficient adhesion of the glass film. Since the adhesion of the glass film becomes unstable as the plate thickness becomes thinner, a technique for further improving the adhesion of the glass film is required. [0012] 　Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a unidirectional electromagnetic steel sheet having excellent film adhesion without impairing magnetic properties and a method for producing the same. Means to solve problems [0013] 　The present inventors have diligently studied in order to solve the above problems. As a result, it was found that the presence of the Mn-containing oxide in the glass film dramatically improves the adhesion of the glass film. It was also found that the application effect of this technology can be obtained particularly remarkably with thin materials. [0014] 　Furthermore, the present inventors have found that Mn-containing oxides can be suitably produced in the glass film by controlling the temperature rising conditions and the atmospheric conditions in the decarburization annealing step and the insulating film forming step in a complex and indivisible manner. I found it. [0015] 　The gist of the present invention is as follows. 　(1) The unidirectional electromagnetic steel sheet according to one aspect of the present invention has Si: 2.50% or more and 4.0% or less and Mn: 0.010% or more and 0.50% or less in mass% as chemical components. , C: 0% or more and 0.20% or less, acid-soluble Al: 0% or more and 0.070% or less, N: 0% or more and 0.020% or less, S: 0% or more and 0.080% or less, Bi: 0 % Or more and 0.020% or less, Sn: 0% or more and 0.50% or less, Cr: 0% or more and 0.50% or less, and Cu: 0% or more and 1.0% or less, and the balance is Fe and It has a silicon steel plate made of impurities, a glass film arranged on the surface of the silicon steel plate, and an insulating film arranged on the surface of the glass film, and the glass film contains an Mn-containing oxide. 　(2) In the unidirectional electrical steel sheet according to (1) above, the Mn-containing oxide may contain at least one selected from brownite or Mn 3 O 4 . 　(3) In the unidirectional electromagnetic steel sheet according to (1) or (2) above, the Mn-containing oxide may be present at the interface with the silicon steel sheet in the glass film. 　(4) In the unidirectional electrical steel sheet according to any one of (1) to (3) above, the Mn-containing oxide is 0.1 pieces / μm 2 or more and 30 pieces at the interface in the glass film. It may be contained in an amount of / μm 2 or less. 　(5) In the unidirectional electromagnetic steel plate according to any one of (1) to (4) above, 41 ° <2θ <43 ° of the X-ray diffraction spectrum of the glass film measured by the X-ray diffraction method. within the range, the diffraction intensity of the peak derived from the forsterite I the for and the diffraction intensity of the peak derived from titanium nitride I TiN when a, I the for and I TiN and a, I TiN ins-S 700-800 . 　(10) In the method for producing a unidirectional electrical steel sheet according to (9) above, in the decarburization annealing step, dec-P 500-600 and dec-S 600-700 are dec-P 500-600 >. Dec-P 600-700 may be satisfied. 　(11) In the method for producing a unidirectional electromagnetic steel sheet according to (9) or (10) above, in the decarburization annealing step, the cold-rolled steel sheet is heated and then subjected to first-stage annealing and second-stage annealing. , dec-T the holding temperature in units ℃ in the first stage annealing I and to and dec-t I oxygen potential PH in and atmosphere was 2 O / PH 2 a dec-P I and, the second stage dec-T at the holding temperature unit ℃ at annealing II dec-t a and to and retention time in units of seconds II oxygen potential PH in and atmosphere was 2 O / PH 2 the dec-P II when a, dec-T I is at 900 ° C. or less 700 ° C. or higher, dec-t I is 1000 seconds or less 10 seconds or more, dec-P I is 0.10 to 1.0 in and, dec-T II is (dec-T I +50) and at 1000 ° C. inclusive ° C., dec-t II is 500 seconds or less than 5 seconds, dec-P II is 0.00001 to 0.10 or less in and, dec-P I and dec-P II and is, dec-P I > dec-P IIMay be satisfied. 　(12) In the method for producing a unidirectional electromagnetic steel plate according to any one of (9) to (11) above, in the decarburization annealing step, dec-P 500-600 and dec-P 600-700 If, dec-P I and, dec-P II is and, dec-P 500-600 > dec-P 600-700 dec-P II may be satisfied. 　(13) In the method for producing a unidirectional electromagnetic steel plate according to any one of (9) to (12) above, in the insulating film forming step, when the temperature of the finished annealed plate is raised, the temperature is 600 ° C. or higher and 700. The oxygen potential PH 2 O / PH 2 in the atmosphere in the temperature range of ° C. or lower is set to ins-P 600-700, and the oxygen potential PH 2 O / PH 2 in the atmosphere in the temperature range of 700 ° C. or higher and 800 ° C. or lower is set. When ins-P 700-800 , ins-P 600-700 is 1.0 or more, ins-P 700-800 is 0.1 or more and 5.0 or less, and ins-P 600-700 and ins-P 700-800 are ins-P 600-. 700 > ins-P 700-800 may be satisfied. 　(14) In the method for producing a unidirectional electrical steel sheet according to any one of (9) to (13) above, in the finishing annealing step, a Ti compound is added to the annealing separator in an amount of 0.5 in terms of metal Ti. It may be contained in mass% or more and 10 mass% or less. 　(15) In the method for producing a unidirectional electromagnetic steel sheet according to any one of (9) to (14) above, the steel piece is a chemical component in mass% and C: 0.01% or more 0. .20% or less, acid-soluble Al: 0.01% or more and 0.070% or less, N: 0.0001% or more and 0.020% or less, S: 0.005% or more and 0.080% or less, Bi: 0. Consists of 001% or more and 0.020% or less, Sn: 0.005% or more and 0.50% or less, Cr: 0.01% or more and 0.50% or less, and Cu: 0.01% or more and 1.0% or less. It may contain at least one selected from the group. Effect of the invention [0016] 　According to the above aspect of the present invention, it is possible to provide a unidirectional electromagnetic steel sheet having excellent film adhesion and a method for producing the same without impairing the magnetic properties. A brief description of the drawing [0017] FIG. 1 is a schematic cross-sectional view showing a unidirectional electrical steel sheet according to an embodiment of the present invention. FIG. 2 is a flow chart showing a method for manufacturing a unidirectional electrical steel sheet according to the present embodiment. Mode for carrying out the invention [0018] 　Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the configuration disclosed in the present embodiment, and various modifications can be made without departing from the spirit of the present invention. In addition, the lower limit value and the upper limit value are included in the numerical limitation range described below. Numerical values ​​that indicate "greater than" or "less than" are not included in the numerical range. “%” Regarding the content of each element means “mass%” unless otherwise specified. [0019] 　First, the process leading up to this embodiment will be described. [0020] 1. 1. Background to the 　present embodiment The present inventors have focused on the morphology of the glass film in order to ensure the adhesion between the glass film and the silicon steel sheet (base steel sheet). In the first place, the adhesion between the glass film and the steel sheet largely depends on the morphology of the glass film. That is, when the glass film has a structure that bites into the silicon steel plate (hereinafter, a fitting structure), the adhesion of the glass film is good. [0021] 　However, it is difficult to secure the adhesiveness of the glass film, and it is particularly difficult to secure the adhesiveness of the glass film as the plate thickness becomes thinner. Although the cause of this is not completely clear, the present inventors consider that the oxide film formation behavior in decarburization annealing is peculiar to thin materials. [0022] 　In response to such a problem, the present inventors have conceived a technique of forming an oxide anchor between the glass film and the silicon steel plate to ensure the adhesion of the glass film. Then, as an anchor oxide precipitation control, attention was paid to the annealing conditions (heat treatment conditions) of the decarburization annealing step and the insulating film forming step, and intensive studies were repeated. As a result, it was found that the adhesion of the glass film is remarkably improved by controlling the temperature rising condition and the atmosphere condition of the decarburization annealing step and the insulating film forming step in a complex and indivisible manner. [0023] 　As a result of analyzing the material having good adhesion of the glass film, Mn-containing oxide was confirmed at the interface between the glass film and the silicon steel plate. As a result of detailed investigation by a transmission electron microscope (hereinafter, TEM) and X-ray diffraction (hereinafter, XRD), this Mn-containing oxide is preferably brownite (Mn 7 SiO 12 ) or trimanganese tetraoxide (Mn 3 O 4). ), And it was clarified that this Mn-containing oxide functions as an anchor oxide. Furthermore, as a result of examining the formation mechanism of Mn-containing oxide, it was clarified that Mn-containing oxide is formed by the following mechanism. [0024] 　First, when the temperature rise rate and atmosphere in the temperature rise process during decarburization annealing are controlled, a Mn-containing oxide precursor (hereinafter, Mn-containing precursor) is generated near the surface of the steel sheet, and this decarburization When the charcoal-annealed plate is finish-annealed, Mn is concentrated between the glass film and the silicon steel sheet (hereinafter referred to as interfacially enriched Mn). 　Secondly, when the temperature rise rate in the temperature rise process at the time of forming the insulating film is controlled by using the above-mentioned finish annealing plate, Mn-containing oxide is formed from the Mn-containing precursor and the interface-concentrated Mn, and the Mn-containing oxide is formed. Oxides (particularly brownite or trimanganese tetraoxide) serve as anchors and contribute to improving the adhesion of the glass film. [0025] 　As described above, the present inventors have focused on the existence state of the Mn-containing oxide in the glass film and the control method thereof, and have obtained the present embodiment. [0026] 2. 2. One-way electrical steel sheet 　Next, the unidirectional electrical steel sheet according to the present embodiment will be described. 2.1 Main configuration of unidirectional electrical steel sheet 　FIG. 1 is a schematic cross-sectional view showing a unidirectional electrical steel sheet according to the present embodiment. The unidirectional electromagnetic steel sheet 1 according to the present embodiment includes a silicon steel sheet (base steel sheet) 11 having a secondary recrystallization structure, a glass film (primary film) 13 arranged on the surface of the silicon steel sheet 11, and glass. It has an insulating film (secondary film) 15 arranged on the surface of the film 13, and the glass film 13 contains an Mn-containing oxide 131. The glass film and the insulating film may be formed on at least one surface of the silicon steel sheet, but are usually formed on both sides of the silicon steel sheet. [0027] 　Hereinafter, the unidirectional electrical steel sheet according to the present embodiment will be described focusing on its characteristic configuration. The description of known configurations and some configurations that can be implemented by those skilled in the art has been omitted. [0028] (Glass film) 　glass coating, magnesium silicate (MgSiO 3 or Mg 2 SiO 4 is a coating of minerals as the main component, etc.). The glass film is generally formed by reacting an annealing separator containing magnesia with an oxide film such as SiO2 on the surface of a silicon steel sheet or an element contained in the silicon steel sheet during finish annealing. Therefore, the glass film has a composition derived from the components of the annealing separator and the silicon steel plate. For example, the glass film may contain spinel (MgAl2O4) and the like. In the unidirectional electromagnetic steel sheet according to the present embodiment, the glass film contains an Mn-containing oxide. [0029] 　As described above, in the unidirectional electromagnetic steel sheet according to the present embodiment, the film adhesion is improved by intentionally forming an Mn-containing oxide in the glass film. If the Mn-containing oxide is present in the glass film, the film adhesion is improved, and therefore the abundance ratio of the Mn-containing oxide in the glass film is not particularly limited. In the present embodiment, the Mn-containing oxide may be contained in the glass film. [0030] 　However, in the unidirectional electromagnetic steel sheet according to the present embodiment, the above-mentioned Mn-containing oxide contains at least one selected from brownite (Mn 7 SiO 12 ) or trimanganese tetraoxide (Mn 3 O 4 ). Is preferable. In other words, it is preferable that the glass film contains at least one selected from brownite or Mn 3 O 4 as the Mn-containing oxide . If brownite or trimanganese tetraoxide is contained in the glass film as the Mn-containing oxide, the film adhesion can be improved without impairing the magnetic properties. [0031] 　Further, if the Mn-containing oxide (brownite or Mn 3 O 4 ) is present in the glass film near the interface between the glass film and the silicon steel plate, the anchor effect can be preferably exhibited. Therefore, the Mn-containing oxide (brownite or Mn 3 O 4 ) is preferably present at the interface between the glass film and the silicon steel plate in the glass film. [0032] 　Further, in addition to the Mn-containing oxide (brownite or Mn 3 O 4 ) being present at the interface with the silicon steel plate in the glass film, the Mn-containing oxide (brownite or Mn 3 O 4 ) is present in the glass film. It is more preferable that the interface contains 0.1 pieces / μm 2 or more and 30 pieces / μm 2 or less in a number density. If the Mn-containing oxide (brownite or Mn 3 O 4 ) is contained at the interface between the glass film and the silicon steel plate in the glass film at the above number density, the anchor effect can be more preferably exhibited. [0033] 　In order to obtain a preferable anchor effect, the lower limit of the number density of the Mn-containing oxide (brownite or Mn 3 O 4 ) is preferably 0.5 pieces / μm 2 , preferably 1.0 piece / μm 2. Is more preferable, and 2.0 pieces / μm 2 is most preferable. On the other hand, in order to avoid deterioration of the magnetic properties due to the unevenness of the interface, the upper limit of the number density of the Mn-containing oxide (brownite or Mn 3 O 4 ) is preferably 20 pieces / μm 2 . It is more preferably 15 pieces / μm 2 and most preferably 10 pieces / μm 2 . [0034] Method for confirming 　Mn-containing oxide (brownite or Mn 3 O 4 ) in the glass film, and Mn-containing oxide (brownite or Mn 3 O 4 ) present at the interface between the glass film and the silicon steel plate in the glass film. The measuring method of is described in detail later. [0035] 　Further, in the conventional unidirectional electromagnetic steel sheet, the glass film may contain Ti. In this case, Ti contained in the glass film reacts with N discharged from the silicon steel plate by purification during finish annealing to form TiN in the glass film. On the other hand, in the unidirectional electromagnetic steel sheet according to the present embodiment, almost no TiN is contained in the glass film even after finish annealing, regardless of whether the glass film contains Ti. [0036] 　In the unidirectional electromagnetic steel sheet according to the present embodiment, N discharged from the silicon steel sheet during finish annealing is trapped by an Mn-containing precursor or interface-enriched Mn existing at the interface between the glass film and the silicon steel sheet. Therefore, even if the glass film contains Ti, N discharged from the silicon steel plate during finish annealing is unlikely to react with Ti in the glass film, so that the formation of TiN is suppressed. [0037] 　For example, in the unidirectional magnetic steel sheet according to the present embodiment, regardless of whether or not the glass film contains Ti, as final products, forsterite (Mg 2 SiO 4 ), which is the main component in the glass film, and glass. The titanium nitride (TiN) in the film may satisfy the following conditions. [0038] 　41 ° in X-ray diffraction spectrum of the glass coating film was measured by X-ray diffractometry I For as the final product . [0039] 　The method of measuring the X-ray diffraction spectrum of the glass film by the X-ray diffraction method will be described in detail later. [0040] (Secondary Recrystallization Grain Size of Silicon Steel Sheet) In the 　unidirectional electromagnetic steel sheet according to the present embodiment, the silicon steel sheet has a secondary recrystallization structure. For example, when the magnetic flux density B8 is 1.89T or more and 2.00T or less, it can be determined that the silicon steel sheet has a secondary recrystallization structure. It is preferable that the secondary recrystallization grain size of the silicon steel sheet is coarse. Thereby, more excellent film adhesion can be obtained. Specifically, it is preferable that the silicon steel plate contains 20% or more of secondary recrystallized grains having a maximum diameter of 30 mm or more and 100 mm or less in proportion to all the secondary recrystallized grains. The number ratio is more preferably 30% or more. The upper limit of the number ratio is not particularly limited, but as a value that can be industrially controlled, this upper limit may be set to 80%. [0041] 　As described above, in the present embodiment, Mn-containing oxide at the interface between the glass film and the silicon steel sheet (Blau night or Mn 3 O 4 and) is produced as an anchor to improve the glass film adhesion. The place where the anchor is formed is preferably inside the secondary recrystallized grain rather than at the secondary recrystallized grain boundary. Since the grain boundaries are an aggregate of lattice defects, even if Mn-containing oxides are formed at the grain boundaries, it is difficult for the Mn-containing oxides to fit into the silicon steel sheet as anchors. Therefore, in a silicon steel sheet in which coarse secondary recrystallized grains are frequently present, the possibility that Mn-containing oxides are formed in the grains increases, so that the film adhesion can be further improved. [0042] 　In this embodiment, the maximum diameters of the secondary recrystallized grains and the secondary recrystallized grains are defined as follows. Regarding the crystal grains of the silicon steel plate, the longest line segment in one crystal grain among the line segments parallel to the rolling direction and the plate width direction (direction perpendicular to rolling) is defined as the maximum diameter of the crystal grains. In addition, the crystal grains having a maximum diameter of 15 mm or more are regarded as secondary recrystallized grains. [0043] 　The method for measuring the above-mentioned number ratio with respect to the coarse secondary recrystallized grains will be described in detail later. [0044] (Thickness of Silicon Steel Sheet) In the 　unidirectional electromagnetic steel sheet according to the present embodiment, the thickness of the silicon steel sheet is not particularly limited. For example, the average thickness of the silicon steel plate may be 0.17 mm or more and 0.29 mm or less. However, in the unidirectional electromagnetic steel sheet according to the present embodiment, when the thickness of the silicon steel sheet is thin, the effect of improving the film adhesion can be remarkably obtained. Therefore, the average thickness of the silicon steel plate is preferably 0.17 mm or more and less than 0.22 mm, and more preferably 0.17 mm or more and 0.20 mm or less. [0045] 　The reason why the effect of improving film adhesion is remarkably obtained with a thin material is unknown at this time, but the following actions are considered. As described above, in this embodiment, it is necessary to generate Mn-containing oxides (particularly brownite or Mn 3 O 4 ). The formation of this Mn-containing oxide is controlled by the situation in which Mn in the steel diffuses to the surface of the steel sheet. For example, a thin material has a larger ratio of surface area to volume than a thick material. Therefore, in the thin material, the diffusion distance of Mn from the inside of the steel sheet to the surface of the steel sheet is short. As a result, in the thin material, the time for Mn to diffuse from the inside of the steel sheet and reach the surface of the steel sheet is substantially short, and the Mn-containing oxide is more likely to be formed as compared with the thick material. For example, as will be described in detail later, with a thin material, it is possible to efficiently produce a Mn-containing precursor in a low temperature range of 500 to 600 ° C. in the temperature raising process during decarburization annealing. [0046] 2.2 Components 　Next, regarding the unidirectional electromagnetic steel sheet according to the present embodiment, the chemical components of the silicon steel sheet will be described. In the present embodiment, the silicon steel sheet contains a basic element as a chemical component, and if necessary, a selective element, and the balance is composed of Fe and impurities. [0047] 　In the present embodiment, the silicon steel plate contains Si and Mn as basic elements (main alloy elements). [0048] 　(Si: 2.50% or more and 4.0% or less) 　Si (silicon) is a basic element. When the Si content is less than 2.50%, the steel undergoes phase transformation during secondary recrystallization annealing, secondary recrystallization does not proceed sufficiently, and good magnetic flux density and iron loss characteristics are obtained. Absent. Therefore, the Si content is set to 2.50% or more. The Si content is preferably 3.00% or more, more preferably 3.20% or more. On the other hand, if the Si content exceeds 4.0%, the steel sheet becomes brittle and the plate-passability is significantly deteriorated during production. Therefore, the Si content is set to 4.0% or less. The Si content is preferably 3.80% or less, more preferably 3.60% or less. [0049] 　( 　Mn 0.010% or more and 0.50% or less) Mn (manganese) is a basic element. When the Mn content is less than 0.010%, even if the decarburization annealing step and the insulating film forming step are controlled, the Mn-containing oxide (brownite or Mn 3 O 4 ) is contained in the glass film . It's difficult. Therefore, the Mn content is set to 0.010% or more. The Mn content is preferably 0.03% or more, more preferably 0.05% or more. On the other hand, when the Mn content exceeds 0.5%, the steel undergoes phase transformation during secondary recrystallization annealing, secondary recrystallization does not proceed sufficiently, and good magnetic flux density and iron loss characteristics are obtained. Since there is no Mn content, the Mn content is 0.50% or less. The Mn content is preferably 0.2% or less, more preferably 0.1% or less. [0050] 　In the present embodiment, the silicon steel plate may contain impurities. In addition, "impurities" refer to those mixed from ore or scrap as a raw material, from the manufacturing environment, etc. when steel is industrially manufactured. [0051] 　Further, in the present embodiment, the silicon steel plate may contain a selective element in addition to the above-mentioned basic elements and impurities. For example, C, acid-soluble Al, N, S, Bi, Sn, Cr, Cu and the like may be contained as a selective element instead of a part of Fe which is the balance described above. These selective elements may be contained according to the purpose. Therefore, it is not necessary to limit the lower limit values ​​of these selective elements, and the lower limit value may be 0%. Further, even if these selective elements are contained as impurities, the above effects are not impaired. [0052] 　(C: 0% or more and 0.20% or less) 　C (carbon) is a selective element. If the C content exceeds 0.20%, the steel undergoes phase transformation during secondary recrystallization annealing, secondary recrystallization does not proceed sufficiently, and good magnetic flux density and iron loss characteristics cannot be obtained. There is. Therefore, the C content may be 0.20% or less. The content of C is preferably 0.15% or less, more preferably 0.10% or less. The lower limit of the C content is not particularly limited and may be 0%. However, since C has the effect of adjusting the primary recrystallization texture and improving the magnetic flux density, the lower limit of the C content may be 0.01% or 0.03%. It may be 0.06%. If decarburization by decarburization annealing is insufficient and C remains excessively as an impurity in the final product, the magnetic characteristics may be adversely affected. Therefore, the C content of the silicon steel sheet is preferably 0.0050% or less. Further, the C content of the silicon steel sheet may be 0%, but it is not industrially easy to actually set it to 0%, so the C content of the silicon steel sheet may be 0.0001% or more. [0053] 　(Acid-soluble Al: 0% or more and 0.070% or less) 　Acid-soluble Al (aluminum) (sol.Al) is a selective element. If the content of acid-soluble Al exceeds 0.070%, embrittlement may become significant. Therefore, the content of acid-soluble Al may be 0.070% or less. The content of acid-soluble Al is preferably 0.05% or less, more preferably 0.03% or less. The lower limit of the acid-soluble Al content is not particularly limited and may be 0%. However, since the acid-soluble Al has an effect of making secondary recrystallization preferable, the lower limit of the acid-soluble Al content may be 0.01% or 0.02%. If the purification at the time of finish annealing is insufficient and Al remains excessively as impurities in the final product, the magnetic characteristics may be adversely affected. Therefore, the acid-soluble Al content of the silicon steel sheet is preferably 0.0100% or less. Further, the Al content of the silicon steel sheet may be 0%, but it is not industrially easy to actually make it 0%, so that the acid-soluble Al content of the silicon steel sheet may be 0.0001% or more. Good. [0054] 　(N: 0% or more and 0.020% or less) 　N (nitrogen) is a selective element. If the N content exceeds 0.020%, blisters (vacancy) are generated in the steel sheet during cold spreading, the strength of the steel sheet is increased, and the sheet passability during manufacturing may be deteriorated. Therefore, the content of N may be 0.020% or less. The content of N is preferably 0.015% or less, more preferably 0.010% or less. The lower limit of the N content is not particularly limited and may be 0%. However, since N forms AlN and has an effect as an inhibitor at the time of secondary recrystallization, the lower limit of the content of N may be 0.0001%, even 0.005%. Good. If the purification at the time of finish annealing is insufficient and N remains excessively as impurities in the final product, the magnetic characteristics may be adversely affected. Therefore, the N content of the silicon steel sheet is preferably 0.0100% or less. Further, the N content of the silicon steel sheet may be 0%, but it is not industrially easy to actually set it to 0%, so the N content of the silicon steel sheet may be 0.0001% or more. [0055] 　(S: 0% or more and 0.080% or less) 　S (sulfur) is a selective element. If the S content exceeds 0.080%, it causes hot brittleness and may make hot spreading extremely difficult. Therefore, the S content may be 0.080% or less. The content of S is preferably 0.04% or less, more preferably 0.03% or less. The lower limit of the S content is not particularly limited and may be 0%. However, since S forms MnS and has an effect as an inhibitor at the time of secondary recrystallization, the lower limit of the content of S may be 0.005%, even if it is 0.01%. Good. If the purification at the time of finish annealing is insufficient and S remains excessively as an impurity in the final product, the magnetic characteristics may be adversely affected. Therefore, the S content of the silicon steel sheet is preferably 0.0100% or less. Further, the S content of the silicon steel sheet may be 0%, but it is not industrially easy to actually set it to 0%, so the S content of the silicon steel sheet may be 0.0001% or more. [0056] 　(Bi: 0% or more and 0.020% or less) 　Bi (bismuth) is a selective element. If the Bi content exceeds 0.020%, the plate-passability during cold spreading may deteriorate. Therefore, the Bi content may be 0.020% or less. The Bi content is preferably 0.0100% or less, more preferably 0.0050% or less. The lower limit of the Bi content is not particularly limited and may be 0%. However, since Bi has the effect of improving the magnetic characteristics, the lower limit of the Bi content may be 0.0005% or 0.0010%. If the purification at the time of finish annealing is insufficient and Bi remains excessively as an impurity in the final product, the magnetic characteristics may be adversely affected. Therefore, the Bi content of the silicon steel sheet is preferably 0.0010% or less. Further, the Bi content of the silicon steel sheet may be 0% as the lower limit, but it is not industrially easy to actually set it to 0%. Good. [0057] 　(Sn: 0% or more and 0.50% or less) 　Sn (tin) is a selective element. If the Sn content exceeds 0.50%, the secondary recrystallization becomes unstable and the magnetic properties may deteriorate. Therefore, the Sn content may be 0.50% or less. The Sn content is preferably 0.30% or less, more preferably 0.15% or less. The lower limit of the Sn content is not particularly limited and may be 0%. However, since Sn has an effect of improving film adhesion, the lower limit of the Sn content may be 0.005% or 0.01%.　 [0058] 　(Cr: 0% or more and 0.50% or less) 　Cr (chromium) is a selective element. If the Cr content exceeds 0.50%, Cr oxide may be formed and the magnetism may be deteriorated. Therefore, the Cr content may be 0.50% or less. The Cr content is preferably 0.30% or less, more preferably 0.10% or less. The lower limit of the Cr content is not particularly limited and may be 0%. However, since Cr has the effect of improving the film adhesion, the lower limit of the Cr content may be 0.01% or 0.03%. [0059] 　(Cu: 0% or more and 1.0% or less) 　Cu (copper) is a selective element. If the Cu content exceeds 1.0%, the steel sheet may become embrittled during hot rolling. Therefore, the Cu content may be 1.0% or less. The Cu content is preferably 0.50% or less, more preferably 0.10% or less. The lower limit of the Cu content is not particularly limited and may be 0%. However, since Cu has the effect of improving the film adhesion, the lower limit of the Cu content may be 0.01% or 0.03%. [0060] 　In the present embodiment, the silicon steel sheet has C: 0.0001% or more and 0.0050% or less, acid-soluble Al: 0.0001% or more and 0.0100% or less, N: 0.0001 in mass% as a chemical component. % Or more and 0.0100% or less, S: 0.0001% or more and 0.0100% or less, Bi: 0.0001% or more and 0.0010% or less, Sn: 0.005% or more and 0.50% or less, Cr: 0 It may contain at least one selected from the group consisting of 0.01% or more and 0.50% or less, and Cu: 0.01% or more and 1.0% or less. [0061] 　Further, in the present embodiment, the silicon steel plate is used as a selective element instead of a part of the above Fe, Mo, W, In, B, Sb, Au, Ag, Te, Ce, V, Co, Ni, Se. , Ca, Re, Os, Nb, Zr, Hf, Ta, Y, La, Cd, Pb, As may contain at least one selected from the group. These selective elements may be contained in a total of 5.00% or less, preferably 3.00% or less, and more preferably 1.00% or less. The lower limit of the content of these selective elements is not particularly limited and may be 0%. [0062] 2.3 Measurement method of technical features 　Next, regarding the unidirectional electromagnetic steel sheet according to the present embodiment, the measurement method of each technical feature described above will be described. [0063] 　First, the layered structure of the unidirectional electrical steel sheet according to the present embodiment may be observed and measured as follows. [0064] 　A test piece is cut out from the unidirectional electromagnetic steel plate on which each layer is formed, and the layer structure of the test piece is observed with a scanning electron microscope (SEM) or a transmission electron microscope (TEM). For example, a layer having a thickness of 300 nm or more may be observed by SEM, and a layer having a thickness of less than 300 nm may be observed by TEM. [0065] 　Specifically, first, the test piece is cut out so that the cutting direction is parallel to the plate thickness direction (specifically, the in-plane direction of the cut surface is parallel to the plate thickness direction and the normal direction of the cut surface). The test piece is cut out so that is perpendicular to the rolling direction), and the cross-sectional structure of this cut surface is observed by SEM at a magnification (for example, 2000 times) at which each layer is included in the observation field. For example, by observing with a backscattered electron composition image (COMPO image), it is possible to infer how many layers the cross-sectional structure is composed of. For example, in the COMPO image, the silicon steel plate can be identified as a light color, the glass film as a dark color, and the insulating film as an intermediate color. [0066] 　In order to identify each layer in the cross-sectional structure, SEM-EDS (Energy Dispersive X-ray Spectroscopy) is used to perform line analysis along the plate thickness direction, and quantitative analysis of the chemical composition of each layer is performed. The elements to be quantitatively analyzed are 6 elements of Fe, P, Si, O, Mg and Al. The apparatus to be used is not particularly limited, but in this embodiment, for example, SEM (JEOL JSM-7000F), EDS (AMETEK GENESIS4000), and EDS analysis software (AMETEK GENESIS SPECTRUM Ver.4.61J) may be used. [0067] 　From the observation results of the COMPO image and the quantitative analysis results of SEM-EDS described above, it is a layered region existing at the deepest position in the plate thickness direction, and the Fe content is 80 atomic% or more excluding the measurement noise. If the region has an O content of less than 30 atomic% and the line segment (thickness) on the scanning line of the line analysis corresponding to this region is 300 nm or more, it is determined that this region is a silicon steel plate. However, the region excluding the silicon steel plate is judged to be a glass film and an insulating film. [0068] 　Regarding the region excluding the silicon steel plate specified above, the Fe content is less than 80 atomic% and the P content is 5 atomic% or more, excluding the measurement noise, from the observation results in the COMPO image and the quantitative analysis results of SEM-EDS. If the O content is a region of 30 atomic% or more and the line segment (thickness) on the scanning line of the line analysis corresponding to this region is 300 nm or more, this region is one of the insulating films. Judged as a certain phosphoric acid-based film. In addition to the above three elements which are judgment elements for specifying the phosphoric acid-based film, the phosphoric acid-based film may contain aluminum, magnesium, nickel, chromium, etc. derived from a phosphate. In addition, silicon derived from colloidal silica may be contained. [0069] 　When determining the region of the phosphoric acid-based film, the precipitates, inclusions, vacancies, etc. contained in each film are not included in the judgment, and the above quantitative analysis results are satisfied as the matrix. The region to be treated is judged to be a phosphoric acid-based film. For example, if it is confirmed from the COMPO image or the line analysis result that precipitates, inclusions, pores, etc. are present on the scanning line of the line analysis, the quantitative analysis result as the matrix without including this region is included. Judge by. Precipitates, inclusions, and pores can be distinguished from the matrix by contrast in the COMPO image, and can be distinguished from the matrix by the abundance of constituent elements in the quantitative analysis results. When specifying the phosphoric acid-based film, it is preferable to specify it at a position where precipitates, inclusions, and pores are not included on the scanning line of the line analysis. [0070] 　If it is a region excluding the silicon steel plate specified above and the insulating film (phosphoric acid-based coating), and the line segment (thickness) on the scanning line of the line analysis corresponding to this region is 300 nm or more, this Judge the area as a glass film. The average Fe content of this glass film is less than 80 atomic%, the average P content is less than 5 atomic%, the average Si content is 5 atomic% or more, and the average O content is 30. It is sufficient that the atomic% or more and the Mg content are 10 atomic% or more on average. The quantitative analysis result of the glass film is a quantitative analysis result as a matrix phase, which does not include the analysis results of precipitates, inclusions, pores and the like contained in the glass film. When specifying the glass film, it is preferable to specify it at a position on the scanning line of the line analysis that does not include precipitates, inclusions, and vacancies. [0071] 　The above-mentioned COMPO image observation and SEM-EDS quantitative analysis are used to identify each layer and measure the thickness at five or more locations with different observation fields. For the thickness of each layer obtained at 5 or more places in total, the average value is obtained from the values ​​excluding the maximum value and the minimum value, and this average value is taken as the average thickness of each layer. [0072] 　If there is a layer in which the line segment (thickness) on the scanning line of the line analysis is less than 300 nm in at least one of the above-mentioned five or more observation fields, the corresponding layer is observed in detail by TEM. Then, the corresponding layer is identified and the thickness is measured by TEM. [0073] 　A test piece containing a layer to be observed in detail using a TEM is cut out by FIB (Focused Ion Beam) processing so that the cutting direction is parallel to the plate thickness direction (specifically, the in-plane direction of the cut surface is The test piece is cut out so that it is parallel to the plate thickness direction and the normal direction of the cut surface is perpendicular to the rolling direction), and the cross-sectional structure of this cut surface is STEM (STEM) at a magnification that allows the corresponding layer to enter the observation field. Observe (bright-field image) with Scanning-TEM). If each layer does not fit in the observation field of view, observe the cross-sectional structure in a plurality of continuous fields of view. [0074] 　In order to identify each layer in the cross-sectional structure, TEM-EDS is used to perform line analysis along the plate thickness direction and quantitative analysis of the chemical components of each layer. The elements to be quantitatively analyzed are 6 elements of Fe, P, Si, O, Mg and Al. The apparatus to be used is not particularly limited, but in the present embodiment, for example, TEM (JEM-2100PLUS manufactured by JEOL Ltd.), EDS (JED-2100 manufactured by JEOL Ltd.), EDS analysis software (Genesis Spectram Version 4.61J) ) May be used. [0075] 　Each layer is specified from the bright-field image observation result by TEM and the quantitative analysis result of TEM-EDS described above, and the thickness of each layer is measured. The method for specifying each layer using TEM and the method for measuring the thickness of each layer may be performed according to the above-mentioned method using SEM. [0076] 　In the above-mentioned method for specifying each layer, first, the silicon steel sheet is specified in the entire region, then the insulating film (phosphoric acid-based film) is specified in the remaining part, and finally the remaining part is judged to be the glass film. In the case of the unidirectional electromagnetic steel sheet satisfying the configuration of the embodiment, there is no unspecified region other than the above-mentioned layers in the entire region. [0077] Whether or not the 　Mn-containing oxide (brownite or Mn 3 O 4 ) is contained in the glass film specified above may be confirmed by TEM. [0078] 　Within the region of the glass film specified by the above method, measurement points at equal intervals are set on line segments along the plate thickness direction, and electron diffraction is performed at these measurement points. When performing electron diffraction, for example, measurement points at equal intervals are set from the interface with the silicon steel plate to the interface with the insulating film on a line segment along the plate thickness direction, and measurement at equal intervals is performed. The interval between points is set to 1/10 or less of the average thickness of the glass film. Then, a wide range of electron diffraction is performed so that the electron beam diameter is about 1/10 of the glass film. [0079] 　When it is confirmed that the crystalline phase exists in the diffraction pattern of the above-mentioned wide-area electron diffraction, the target crystalline phase is confirmed by a bright-field image, and the target crystalline phase is compared with the crystalline phase. Electron diffraction is performed by narrowing down the electron beam so that information from the phase can be obtained, and the crystal structure and interplanar spacing of the target crystalline phase are specified from the electron diffraction pattern. [0080] 　The crystal data such as the crystal structure and the interplanar spacing specified above are collated with the PDF (Power Diffraction File). By this collation, it can be confirmed whether or not the glass film contains an Mn-containing oxide. For example, JCPDS number: 01-089-5662 may be used for identification of brownite (Mn 7 SiO 12 ). For example, JCPDS number: 01-075-0765 may be used for identification of trimanganese tetraoxide (Mn 3 O 4 ). If the glass film contains an Mn-containing oxide, the effect of the present embodiment can be enjoyed. [0081] 　The line segments along the plate thickness direction described above are set at equal intervals along the direction orthogonal to the plate thickness direction on the observation field of view, and the same electron diffraction as described above is performed on each line segment. Electron diffraction is performed so that the number of line segments set at equal intervals in the plate thickness orthogonal direction is at least 50 and the total measurement points are at least 500 points. [0082] 　As a result of the above identification by electron diffraction, an Mn-containing oxide (brownite or Mn 3 O) is contained in a region of 1/5 of the thickness of the glass film from the interface with the silicon steel plate on the line segment along the plate thickness direction. If 4 ) is confirmed, it is determined that the Mn-containing oxide (brownite or Mn 3 O 4 ) is present at the interface with the silicon steel plate in the glass film. [0083] 　Further, based on the above-mentioned identification result by electron diffraction , the number of Mn-containing oxides (brownite or Mn 3 O 4 ) existing in the region of 1/5 of the thickness of the glass film from the interface with the silicon steel plate is determined. Count. From the number of Mn-containing oxides and the region where the number of Mn-containing oxides was counted (the region from the interface with the silicon steel plate where the number of Mn-containing oxides was counted to 1/5 of the thickness of the glass film). , The number density of Mn-containing oxides (brownite or Mn 3 O 4 ) present at the interface with the silicon steel plate in the glass film is determined in units of: piece / μm 2 . That is, the number of Mn-containing oxides (brownite or Mn 3 O 4 ) existing in the region of 1/5 of the thickness of the glass film from the interface with the silicon steel plate is calculated by the area of ​​the glass film obtained by counting the number. The divided value is regarded as the number density of Mn-containing oxides (brownite or Mn 3 O 4 ) present at the interface in the glass film. [0084] 　Next, the X-ray diffraction spectrum of the glass film described above may be observed and measured as follows. [0085] 　The silicon steel sheet and the insulating film are removed from the unidirectional electromagnetic steel sheet, and only the glass film is extracted. Specifically, first of all, the insulating film is removed from the unidirectional electromagnetic steel sheet by immersing it in an alkaline solution. For example, it is unidirectional by immersing it in a sodium hydroxide aqueous solution of NaOH: 30 to 50% by mass + H 2 O: 50 to 70% by mass at 80 to 90 ° C. for 5 to 10 minutes, washing with water, and drying. The insulating film can be removed from the electromagnetic steel sheet. The time of immersion in the above sodium hydroxide aqueous solution may be changed according to the thickness of the insulating film. [0086] 　Next, a sample of 30 × 40 mm is taken from the electromagnetic steel sheet from which the insulating film has been removed, and this sample is subjected to electrolytic treatment, and only the glass film component is extracted as an electric field residue and subjected to X-ray diffraction. As the electrolysis conditions, for example, constant current electrolysis of 500 mA was used, and as the electrolysis solution, 10% acetylacetone plus 1% tetramethylammonium chloride methanol was used, and electrolysis treatment was carried out for 30 to 60 minutes, and the mesh size was φ0. The film may be recovered as an electric field residue using a .2 μm filter. [0087] 　X-ray diffraction is performed on the above electrolytic extraction residue (glass film). For example, X-ray diffraction is performed using CuKα rays (Kα1) as incident X-rays. For X-ray diffraction, for example, an X-ray diffractometer (RIGAKU RINT2500) may be used for a circular sample having a diameter of 26 mm. Tube voltage 40 kV, tube current 200 mA, measurement angle 5 to 90 °, step width 0.02 °, scan speed 4 ° / min, divergence / scattering slit: 1/2 °, longitudinal limiting slit 10 mm, light receiving slit: It may be 0.15 mm. [0088] 　The obtained X-ray diffraction spectrum is collated with PDF (Power Diffraction File). For example, JCPDS number: 01-084-1402 is used for identification of forsterite (Mg 2 SiO 4 ), and JCPDS number: 031-1403 is used for identification of titanium nitride (TiN, to be exact, TiN 0.90). It may be used. [0089] 　Based on the results of the above PDF verification, within the scope of 41 ° in X-ray diffraction spectrum <2θ <43 °, the diffraction intensity of the peak derived from the forsterite I the For and the diffraction intensity of the peak derived from titanium nitride Let it be I TiN . [0090] 　The peak intensity of X-ray diffraction is the area of ​​the diffraction peak after removing the background. General-purpose software for XRD analysis may be used for background removal and peak area derivation. In deriving the peak area, the spectrum (experimental value) after background removal may be profile-fitted and calculated from the fitting spectrum (calculated value) obtained there. For example, a profile fitting method for an XRD spectrum (experimental value) by Rietveld analysis as described in Non-Patent Document 1 may be adopted. [0091] 　Next, the maximum diameter and the number ratio of the coarse secondary recrystallized grains in the above-mentioned silicon steel sheet may be observed and measured as follows. [0092] 　The glass film and the insulating film are removed from the unidirectional electromagnetic steel sheet, and only the silicon steel sheet is extracted. For example, as a method for removing the insulating film, a unidirectional electromagnetic steel sheet having a film may be immersed in a high-temperature alkaline solution as described above. Specifically, NaOH: 30 ~ 50 wt% + H 2 O: the 50 to 70% by weight aqueous solution of sodium hydroxide, 80 ~ 90 ° C. for 5 to 10 minutes, after immersion, and dried by washing with water, The insulating film can be removed from the unidirectional electromagnetic steel sheet. The time of immersion in the above sodium hydroxide aqueous solution may be changed according to the thickness of the insulating film. [0093] 　Further, for example, as a method for removing the glass film, an electromagnetic steel sheet from which the insulating film has been removed may be immersed in high-temperature hydrochloric acid. Specifically, the concentration of hydrochloric acid preferable for removing the glass film to be dissolved is investigated in advance, and after immersing in hydrochloric acid of this concentration, for example, 30 to 40% by mass hydrochloric acid at 80 to 90 ° C. for 1 to 5 minutes. The glass film can be removed by washing with water and drying. Normally, an alkaline solution is used to remove the insulating film, and hydrochloric acid is used to remove the glass film, so that each treatment solution is used properly to remove each film. 　By removing the insulating film and the glass film, the steel structure of the silicon steel sheet appears and can be observed, and the maximum diameter of the secondary recrystallized grains can be measured. [0094] 　By observing the steel structure of the silicon steel plate revealed by the above, the above-mentioned crystal grains having a maximum diameter of 15 mm or more are regarded as secondary recrystallized grains, and the maximum diameter is 30 mm for all the secondary recrystallized grains. The ratio of crystal grains of 100 mm or more is regarded as the number ratio of coarse secondary recrystallized grains. That is, the percentage of the value obtained by dividing the total number of crystal grains having a maximum diameter of 30 mm or more and 100 mm or less by the total number of crystal grains having a maximum diameter of 15 mm or more is regarded as the number ratio of coarse secondary recrystallized grains. [0095] 　Next, the chemical composition of steel may be measured by a general analytical method. [0096] 　The steel component of the silicon steel sheet may be composed by removing the glass film and the insulating film from the final product, the unidirectional electromagnetic steel sheet, by the above method. Further, the steel component of the silicon steel slab (steel piece) may be subjected to composition analysis by collecting a sample from molten steel before casting or by removing a surface oxide film or the like from the silicon steel slab after casting. The steel component may be measured using ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrum). Note that C and S may be measured by using the combustion-infrared absorption method, N may be measured by using the inert gas melting-thermal conductivity method, and O may be measured by using the inert gas melting-non-dispersion infrared absorption method. [0097] 3. 3. Method for manufacturing unidirectional electromagnetic steel sheet 　Next, a method for manufacturing the unidirectional electromagnetic steel sheet according to the present embodiment will be described. 　The general manufacturing method of the unidirectional electromagnetic steel sheet is as follows. A silicon steel slab containing 7% by mass or less of Si is hot-rolled and annealed by hot rolling. The hot-rolled annealed plate is pickled and then cold-rolled once or twice with intermediate annealing to finish the final plate thickness. Then, decarburization and primary recrystallization are performed by annealing in a moist hydrogen atmosphere (decarburization annealing). In decarburization annealing, an oxide film (Fe 2 SiO 4 or SiO 2 ) is formed on the surface of the steel sheet . Subsequently, an annealing separator mainly composed of MgO is applied to and dried on the decarburized annealing plate, and finish annealing is performed. Due to this finish annealing, secondary recrystallization occurs in the steel sheet, and the crystal orientation is oriented in the {110} <001> orientation. At the same time, on the surface of the steel sheet, MgO in the annealing separator reacts with the oxide film of decarburization annealing to form a glass film (Mg 2 SiO 4 or the like). After demineralizing this finished annealed plate by washing with water or pickling, an insulating film is formed by applying a coating liquid mainly composed of phosphate to the surface and baking. [0098] 　FIG. 2 is a flow chart illustrating a method for manufacturing a unidirectional electrical steel sheet according to the present embodiment. The method for producing a unidirectional electromagnetic steel plate according to the present embodiment includes a hot-rolling step of hot-rolling a silicon steel slab (steel piece) having a predetermined chemical component to obtain a hot-rolled steel plate, and an annealing of the hot-rolled steel plate. A hot-rolled steel sheet annealing step for obtaining a hot-rolled annealed sheet, a cold-rolling step for obtaining a cold-rolled steel sheet by performing a single cold-rolling or a plurality of cold-rolling through annealing, and a cold-rolling process. A decarburization annealing step of applying decarburization annealing to a steel plate to obtain a decarburization annealing plate, and a finish annealing after applying an annealing separator to the decarburization annealing plate to form a glass film on the surface of the decarburization annealing plate. It mainly includes a finishing annealing step of obtaining a finishing annealing plate and an insulating film forming step of applying an insulating film forming liquid to the finishing annealing plate and then performing heat treatment to form an insulating film on the surface of the finishing annealing plate. [0099] 　Each of the above steps will be described in detail. If the conditions for each step are not described in the following description, known conditions may be appropriately applied. [0100] 3.1. Hot-rolling step In the 　hot- rolling step , a steel piece having a predetermined chemical component (for example, a steel ingot such as a slab) is hot-rolled. The chemical composition of the steel piece may be the same as that of the silicon steel sheet described above. [0101] 　For example, the silicon steel slab (steel piece) used in the hot spreading process has Si: 2.50% or more and 4.0% or less, Mn: 0.010% or more and 0.50% or less in mass% as a chemical component. C: 0% or more and 0.20% or less, acid-soluble Al: 0% or more and 0.070% or less, N: 0% or more and 0.020% or less, S: 0% or more and 0.080% or less, Bi: 0% It contains 0.020% or more, Sn: 0% or more and 0.50% or less, Cr: 0% or more and 0.50% or less, and Cu: 0% or more and 1.0% or less, and the balance is from Fe and impurities. It should be. [0102] 　In the present embodiment, the silicon steel slab (steel piece) has C: 0.01% or more and 0.20% or less, acid-soluble Al: 0.01% or more and 0.070% or less in mass% as a chemical component. N: 0.0001% or more and 0.020% or less, S: 0.005% or more and 0.080% or less, Bi: 0.001% or more and 0.020% or less, Sn: 0.005% or more and 0.50% Hereinafter, at least one selected from the group consisting of Cr: 0.01% or more and 0.50% or less, and Cu: 0.01% or more and 1.0% or less may be contained. [0103] 　In the hot rolling process, first, the steel pieces are heat-treated. The heating temperature may be, for example, 1200 ° C. or higher and 1600 ° C. or lower. The lower limit of the heating temperature is preferably 1280 ° C, and the upper limit of the heating temperature is preferably 1500 ° C. The heated steel pieces are then hot rolled. The thickness of the hot-rolled steel sheet after hot rolling is preferably in the range of, for example, 2.0 mm or more and 3.0 mm or less. [0104] 3.2. Hot-rolled steel sheet annealing step In the hot-rolled steel 　sheet annealing step, the hot-rolled steel sheet obtained in the hot-rolled step is annealed. This hot-rolled sheet annealing causes recrystallization in the steel sheet, and finally it becomes possible to realize good magnetic properties. The conditions for annealing the hot-rolled sheet are not particularly limited, but for example, the hot-rolled steel sheet may be annealed in a temperature range of 900 to 1200 ° C. for 10 seconds to 5 minutes. Further, the surface of the hot-rolled annealed plate may be pickled after the hot-rolled annealed plate and before the cold rolling. [0105] 3.3. 　Cold- rolled step In the cold-rolled step, the hot-rolled annealed sheet after the hot-rolled steel sheet annealing step is subjected to one cold-rolling or a plurality of cold-rolling with an intermediate annealing in between. Since the hot-rolled annealed sheet has a good steel sheet shape due to the hot-rolled annealed sheet, the possibility of the steel sheet breaking in the first cold rolling can be reduced. When intermediate annealing is performed during cold rolling, the heating method for intermediate annealing is not particularly limited. Further, the cold rolling may be performed in three or more times with intermediate annealing in between, but since the manufacturing cost increases, it is preferable to perform the cold rolling once or twice. [0106] 　The final cold rolling reduction rate in cold rolling (cumulative cold rolling rate without intermediate annealing or cumulative cold rolling rate after intermediate annealing) is, for example, in the range of 80% or more and 95% or less. do it. By setting the final cold spreading reduction rate within the above range, it is possible to finally increase the degree of integration in the {110} <001> direction and suppress destabilization of secondary recrystallization. Can be done. The thickness of the cold-rolled cold-rolled steel sheet is usually the thickness (final thickness) of the silicon steel sheet of the finally manufactured unidirectional electromagnetic steel sheet. [0107] 3.4. Decarburization annealing step In the 　decarburization annealing step, the cold-rolled steel sheet obtained in the cold-rolling step is decarburized and annealed. [0108] (1) Temperature rise condition In the 　present embodiment, the temperature rise condition when the temperature of the cold-rolled steel sheet is raised is controlled. Specifically, when the temperature of the cold-rolled steel plate is raised, the average heating rate in the temperature range of 500 ° C. or higher and 600 ° C. or lower is set to dec-S 500-600 in a unit ° C./sec, and the oxygen potential PH 2 O in the atmosphere. / PH 2 is set to dec-P 500-600 , the average heating rate in the temperature range of 600 ° C. or higher and 700 ° C. or lower is set to dec-S 600-700 in units of ° C./sec, and the oxygen potential PH 2 O / PH in the atmosphere. When 2 is set to dec-P 600-700 , 　　dec-S 500-600 is 300 ° C./sec or more and 2000 ° C./sec or less, and 　　dec-S 600-700 is 300 ° C./sec or more and 3000 ° C./sec or less. Yes , 　　dec-S 500-600 and dec-S 600-700 are dec-S 500-600.< Satisfying dec-S 600-700 , cold so that 　　dec-P 500-600 is 0.00010 or more and 0.50 or less, and 　　dec-P 600-700 is 0.00001 or more and 0.50 or less. The temperature of the rolled steel sheet is raised. [0109] 　In the heating process during decarburization annealing, the SiO 2 oxide film is most likely to be formed in the temperature range of 600 to 700 ° C. In this temperature range, it is considered that the diffusion rate of Si in the steel and the diffusion rate of O are balanced on the surface of the steel sheet. On the other hand, in the temperature range of 500 to 600 ° C., a Mn-containing oxide precursor (Mn-containing precursor) is likely to be formed. In the present embodiment, it is intended to generate a Mn-containing precursor at the time of decarburization annealing, and finally to improve the film adhesion. Therefore, it is necessary to make the residence time of 500 to 600 ° C., which is the formation temperature range of the Mn-containing precursor, longer than the residence time of 600 to 700 ° C., which is the formation temperature range of the SiO 2 oxide film. [0110] 　Therefore, the dec-S 500-600 is set to 300 ° C./sec or more and 2000 ° C./sec or less, and the dec-S 600-700 is set to 300 ° C./sec or more and 3000 ° C./sec or less, and then the dec-S 500-600 is set. < It is necessary to satisfy dec-S 600-700 . The residence time of 500 to 600 ° C. in the temperature raising process corresponds to the amount of Mn-containing precursor produced, and the residence time of 600 to 700 ° C. in the temperature raising process corresponds to the amount of SiO 2 oxide film produced. Therefore, when dec-S 500-600 is larger than dec-S 600-700 , the amount of Mn-containing precursor produced is smaller than the amount of SiO 2 oxide film produced, and thus the glass film is finally produced. There is a risk that the Mn-containing oxide inside cannot be controlled. The dec-S 600-700 is preferably 1.2 times or more and 5.0 times or less of the dec-S 500-600 . [0111] 　Further, if the dec-S 500-600 is less than 300 ° C./sec, good magnetism cannot be obtained. The dec-S 500-600 is preferably 400 ° C./sec or higher. On the other hand, if dec-S 500-600 exceeds 2000 ° C./sec, the Mn-containing precursor is not suitably formed. The dec-S 500-600 is preferably 1700 ° C./sec or less. [0112] 　It is also important to control the dec-S 600-700 . For example, when the amount of the SiO 2 oxide film formed is extremely small, the formation of the glass film becomes unstable, and defects such as holes may occur in the glass film. Therefore, the dec-S 600-700 is set to 300 ° C./sec or more and 3000 ° C./sec or less. The dec-S 600-700 is preferably at 500 ° C./sec or higher. Further, in order to suppress overshoot, the dec-S 600-700 is preferably set to 2500 ° C./sec or less. [0113] 　If the temperature is maintained at 600 ° C. in the process of raising the temperature during decarburization annealing, each of dec-S 500-600 and dec-S 600-700 may become unclear. In the present embodiment, when the isothermal temperature is maintained at 600 ° C. during the decarburization annealing process, the dec-S 500-600 has a temperature rise rate based on the time when the temperature reaches 500 ° C. and the start of the 600 ° C. isothermal maintenance. Similarly, dec-S 600-700 is defined as the rate of temperature rise based on the period from the end of maintaining the isothermal temperature at 600 ° C. to the time when the temperature reaches 700 ° C. [0114] 　Further, in the present embodiment, in addition to the heating rate, the atmosphere is also controlled in the heating process during decarburization annealing. As described above, the Mn-containing precursor is likely to be formed in the temperature range of 500 to 600 ° C., and the SiO 2 oxide film is likely to be formed in the temperature range of 600 to 700 ° C. The oxygen potential PH 2 O / PH 2 in these temperature ranges affects the thermodynamic stability of the Mn-containing precursor and SiO 2 oxide film produced . Therefore, in order to balance the amount of Mn-containing precursor produced and the amount of SiO 2 oxide film produced, and to control the thermodynamic stability of the produced Mn-containing precursor and SiO 2 oxide film, respectively. It is necessary to control the oxygen potential in the temperature range. [0115] 　Specifically, it is necessary that the dec-P 500-600 is 0.00010 or more and 0.50 or less, and the dec-P 600-700 is 0.00001 or more and 0.50 or less. When dec-P 500-600 and dec-P 600-700 are out of the above range, the amount of Mn-containing precursor and SiO 2 oxide film produced and the thermodynamic stability cannot be preferably controlled, and finally There is a risk that the Mn-containing oxide in the glass film cannot be controlled. [0116] 　The oxygen potential PH 2 O / PH 2 is water vapor partial pressure PH in the atmosphere 2 O and hydrogen partial pressure PH 2 can be defined by the ratio of the. If dec-P 500-600 exceeds 0.50, firelite (Fe 2 SiO 4 ) may be excessively produced and the production of Mn-containing precursor may be inhibited. The upper limit of dec-P 500-600 is preferably 0.3. On the other hand, the lower limit of dec-P 500-600 is not particularly limited, but may be, for example, 0.00010. The lower limit of dec-P 500-600 is preferably 0.0005. [0117] 　Further, when dec-P 600-700 exceeds 0.50, Fe 2 SiO 4 is excessively generated, and it becomes difficult to uniformly form the SiO 2 oxide film, which may cause a defect in the glass film. The upper limit of dec-P 600-700 is preferably 0.3. On the other hand, the lower limit of dec-P 600-700 is not particularly limited, but may be, for example, 0.00001. The lower limit of dec-P 600-700 is preferably 0.00005. [0118] 　After controlling the dec-P 500-600 and the dec-P 600-700 within the above range, the dec-P 500-600 and the dec-P 600-700 are dec-P 500-600 > dec-P 600. It is preferable to satisfy −700 . When the value of dec-P 600-700 is smaller than that of dec-P 500-600 , the amount of Mn-containing precursor and SiO 2 oxide film produced and the thermodynamic stability can be more preferably controlled. [0119] 　The details of the Mn-containing oxide precursor (Mn-containing precursor) produced in the decarburization and annealing step of the present embodiment are unknown at this time, but the Mn-containing precursors are MnO, Mn 2 O 3 , Various manganese oxides such as MnO 2 , MnO 3 , Mn 2 O 7 and / or various Mn—Si based composite oxidations such as tefloite (Mn 2 SiO 4 ) and kunevelite ((Fe, Mn) 2 SiO 4 ). It is considered to be a thing. [0120] 　When the isothermal temperature is maintained at 600 ° C. during the decarburization and quenching process, the dec-P 500-600 has an oxygen potential of PH 2 O / PH based on the time when the temperature reaches 500 ° C. and the end of the 600 ° C. isothermal maintenance. 2 and defines, similarly, dec-P 600-700 oxygen potential PH relative to the until 700 ° C. reached from the end of 600 ° C. isothermal hold 2 O / PH 2 is defined as. [0121] (2) Retention conditions In the 　decarburization annealing step, it is important to satisfy the temperature rise rate and atmosphere in the above-mentioned temperature rise process, and the retention conditions at the decarburization annealing temperature are not particularly limited. Generally, in the decarburization annealing holding process, holding is performed for 10 seconds or more and 10 minutes or less in a temperature range of 700 ° C. or higher and 1000 ° C. or lower. In addition, multi-step annealing may be performed. In this embodiment as well, in the process of retaining decarburization annealing, two-step annealing as described below may be performed. [0122] 　For example, in the decarburization annealing step, the cold-rolled steel sheet was carried out first-stage annealing and the second stage annealing temperature was raised, the first stage dec-T the holding temperature in units ℃ at annealing I units were and retention time dec-t I oxygen potential PH in and atmosphere was 2 O / PH 2 of dec-P I and, dec-T II a and to and retention time in units of seconds dec-t II oxygen potential PH in and atmosphere was 2 O / PH 2 of dec-P II when 　　a, dec-T I is at 700 ° C. or higher 900 ° C. or 　　less, dec-t I is 1000 seconds or more 10 seconds or 　　less, dec-P I is 0.10 to 　　1.0, dec-T II is (dec-T I+50) and a ° C. or higher 1000 ° C. or 　　less, dec-t II is not more than 500 seconds 5 　　seconds, dec-P II is 0.00001 to 0.10 or 　　less, dec-P I and dec-P II and but, dec-P I > dec-P II to satisfy, may hold the cold-rolled steel sheet. [0123] 　In the present embodiment, it is important to control the formation of Mn-containing oxide precursor (Mn-containing precursor) in the temperature raising process during decarburization annealing, but the previous stage is annealed at a low temperature in the holding process. The formation of the Mn-containing precursor may be more preferably controlled by performing two-step annealing in which the latter stage is annealed at a high temperature. [0124] 　For example, in one stage annealing, in view of the decarburization improvement, dec-T I a (sheet temperature) and 700 ° C. or higher 900 ° C. or less, dec-t I a may be set to 10 seconds or more. dec-T I is preferably the lower limit of a 780 ° C., dec-T I limit is preferably 860 ° C.. Further, the lower limit of dec-t I is preferably 50 seconds. The upper limit of dec-t I is not particularly limited, but may be 1000 seconds from the viewpoint of productivity. The upper limit of dec-t I is preferably 300 seconds. [0125] 　Further, in the first stage annealing, from the viewpoint of controlling the Mn-containing precursor, dec-P I a may be set to 0.10 to 1.0. On top of that, dec-P I a, above dec-P 500-600 and dec-P 600-700 it is preferable to a large value compared with. If the oxygen potential is a sufficiently large value during the first-stage annealing, it is possible to suppress the replacement of the Mn-containing precursor with SiO 2 . Further, when this oxygen potential is a sufficiently large value, the decarburization reaction can be sufficiently advanced. However, dec-P I when the value is too large, Mn-containing precursor fayalite (Fe 2 SiO 4 in some cases replaced by). Fe 2 SiO 4 deteriorates the adhesion of the glass film. dec-P I is preferably lower limit is 0.2, dec-P I limit is preferably 0.8. [0126] 　It should be noted that the formation of Fe 2 SiO 4 cannot be completely suppressed only by controlling the first-stage annealing . Therefore, it is preferable to control the second-stage annealing. For example, in a two-stage annealing, dec-T II (the sheet temperature) (dec-T I and +50) ° C. or higher 1000 ° C. or less, dec-t II a may be set to 500 seconds or less than 5 seconds. By carrying out the second stage annealing under the above conditions, Fe during the first stage annealing 2 SiO 4 is be generated, Fe during the second stage annealing 2 SiO 4 is reduced to Mn-containing precursor. dec-T II lower limit of (dec-T I is preferably +100) ° C.. Further, the lower limit of dec-t II is preferably 10 seconds. If dec-t II exceeds 500 seconds, the Mn-containing precursor is reduced to SiO 2 . The upper limit of dec-t II is preferably 100 seconds. [0127] 　Since the second stage annealing is a reducing atmosphere, dec-P II a in terms of the 0.00001 to 0.10 or less, dec-P I > dec-P II should satisfy. By performing the second-stage annealing in the atmosphere of the above conditions, better film adhesion is finally obtained. [0128] 　Further, in the present embodiment, it is preferable to control the oxygen potential PH 2 O / PH 2 through the heating process and the holding process of decarburization annealing . Specifically, in the decarburization annealing step, dec-P 500-600 and, dec-P 600-700 and, dec-P I and, dec-P II is and, dec-P 500-600 > dec-P It is preferable to satisfy 600-700 dec-P II . That is, the oxygen potential is changed to a small value when switching from the temperature range of 500 to 600 ° C. to the temperature range of 600 to 700 ° C. in the temperature rise process, and the temperature range of 600 to 700 ° C. in the temperature rise process is one step of the holding process. It is preferable to change the oxygen potential to a large value when switching to the annealing, and to change the oxygen potential to a small value when switching from the first-stage annealing to the second-stage annealing in the holding process. By controlling the oxygen potential described above, the formation of the Mn-containing precursor can be preferably controlled. [0129] 　In the method for producing a unidirectional electrical steel sheet of the present embodiment, the nitriding treatment may be carried out after decarburization and annealing and before applying the annealing separator. In the nitriding treatment, the nitriding treatment is performed on the steel sheet after decarburization and annealing to manufacture the nitriding treated steel sheet. [0130] 　The nitriding treatment may be carried out under well-known conditions. Preferred nitriding conditions are, for example: 　Nitriding treatment temperature: 700 to 850 ° C. 　Atmosphere in the nitriding treatment furnace (nitriding treatment atmosphere): Atmosphere containing a gas having a nitriding ability such as hydrogen, nitrogen, and ammonia. [0131] 　When the nitriding treatment temperature is 700 ° C. or higher, or the nitriding treatment temperature is 850 ° C. or lower, nitrogen easily penetrates into the steel sheet during the nitriding treatment. If the nitriding treatment is performed within this temperature range, the amount of nitrogen inside the steel sheet can be preferably secured. Therefore, fine AlN is preferably formed in the steel sheet before the secondary recrystallization. As a result, secondary recrystallization is preferably expressed during finish annealing. The time for holding the steel sheet at the nitriding treatment temperature is not particularly limited, but may be, for example, 10 to 60 seconds. [0132] 3.5. Finish annealing step In the 　finish annealing step, a annealing separator is applied to the decarburized annealing plate obtained in the decarburization annealing step to perform finish annealing. Finish annealing may be performed for a long time with the steel sheet wound in a coil shape. In order to prevent the coiled steel sheet from being seized during finish annealing, an annealing separator is applied to the decarburized annealing plate and dried before finish annealing. [0133] 　The annealing separator may contain magnesia (MgO) as a main component. Further, the annealing separator may contain a Ti compound in an amount of 0.5% by mass or more and 10% by mass or less in terms of metallic Ti. At the time of finish annealing, MgO in the annealing separator reacts with the oxide film of decarburization annealing to form a glass film (Mg 2 SiO 4 or the like). Normally, when Ti is contained in the annealing separator, TiN is formed in the glass film, but in the present embodiment, TiN is formed in the glass film due to the presence of the Mn-containing precursor and the interface-enriched Mn. Being suppressed. [0134] 　The annealing conditions for finish annealing are not particularly limited, and known conditions may be appropriately adopted. For example, in finish annealing, a decarburized annealing plate coated with an annealing separator and dried may be held in a temperature range of 1000 ° C. or higher and 1300 ° C. or lower for 10 hours or longer and 60 hours or shorter. By performing finish annealing under these conditions, secondary recrystallization is developed and Mn is concentrated between the glass film and the silicon steel plate, so that the film adhesion can be improved without impairing the magnetic properties. The atmosphere at the time of finishing annealing may be, for example, a nitrogen atmosphere or a mixed atmosphere of nitrogen and hydrogen. When the finish annealing atmosphere is a mixed atmosphere of nitrogen and hydrogen, the oxygen potential may be 0.5 or less. [0135] 　Due to this finish annealing, secondary recrystallization occurs in the steel sheet, and the crystal orientation is oriented in the {110} <001> orientation. In this secondary recrystallization structure, the axes that are easily magnetized are aligned in the rolling direction, and the crystal grains are coarse. Due to this secondary recrystallization structure, excellent magnetic properties can be obtained. Further, after the finish annealing and before the formation of the insulating film, the surface of the finish annealing plate may be washed with water or pickled to remove the powder. [0136] 　In the present embodiment, Mn is diffused from the steel during finish annealing, and Mn is concentrated at the interface between the glass film and the silicon steel plate (interface-enriched Mn). The reason why Mn is concentrated at the interface is unknown at this time, but it is considered that the presence of the Mn-containing precursor near the surface of the decarburized annealed plate has an effect. When there is no Mn-containing precursor near the surface of the decarburized annealed plate as in the prior art, Mn is difficult to concentrate at the interface between the glass film and the silicon steel plate, and even if Mn is concentrated at the interface It is difficult to obtain the interface-enriched Mn as in the embodiment. [0137] 3.6. Insulation film forming step In the 　insulation film forming step, the insulating film forming liquid is applied to the finish annealing plate after the finish annealing step and heat-treated. By this heat treatment, an insulating film is formed on the surface of the finished annealed plate. For example, the insulating film forming liquid may contain colloidal silica and phosphate. Chromium may be contained in the insulating film forming liquid. [0138] (1) Temperature rise condition In the 　present embodiment, the temperature rise condition when the temperature of the finished annealed plate coated with the insulating film forming liquid is raised is controlled. Specifically, finishing time of the annealed sheet to raise the temperature, an average Atsushi Nobori rate of the temperature range of 600 ° C. or higher 700 ° C. or less in units ° C. / sec ins-S 600-700 and, 700 ° C. or higher 800 ° C. temperature below When the average heating rate in the region is ins-S 700-800 in units of ° C./sec , 　　ins-S 600-700 is 10 ° C./sec or more and 200 ° C./sec or less, and 　　ins-S 700-800 is 5. Finishing blunt plate so that the temperature is ℃ / sec or more and 100 ℃ / sec or less, and 　　ins-S 600-700 and ins-S 700-800 satisfy ins-S 600-700 > ins-S 700-800. To raise the temperature. [0139] 　As described above, in the finished annealed sheet, the Mn-containing precursor is present at the interface between the glass film and the silicon steel sheet (base steel sheet), and Mn is concentrated. After finish annealing and before the formation of the insulating film, Mn may be present at the interface as a Mn-containing precursor or as an interface-enriched Mn (an atom of Mn alone). When an insulating film is formed under the above-mentioned temperature rising conditions using this finished annealed plate, an Mn-containing oxide (brownite or trimanganese tetraoxide) is produced from the Mn-containing precursor and the interface-concentrated Mn. [0140] 　In order to preferentially produce Mn-containing oxides, particularly Mn 7 SiO 12 (brownite) and trimanganese tetraoxide (Mn 3 O 4 ), SiO 2 or Fe system is used when the temperature is raised to form an insulating film. It is necessary to suppress the formation of oxides. Since SiO 2 or Fe-based oxide has a highly symmetric structure such as a sphere or a rectangle, the function as an anchor is not sufficient and does not contribute to the improvement of film adhesion. SiO 2 or Fe-based oxides are preferentially produced in a temperature range of 600 to 700 ° C. when the temperature is raised to form an insulating film. On the other hand, the Mn-containing oxide (brownite or Mn 3 O 4 ) is preferentially produced in the temperature range of 700 to 800 ° C. Therefore, the residence time of 600 to 700 ° C., which is the formation temperature range of SiO 2 or Fe-based oxide, is set to the residence time of 700 to 800 ° C., which is the formation temperature range of Mn-containing oxide (brownite or Mn 3 O 4 ). It is necessary to make it shorter than that. [0141] 　Therefore, ins-S 600-700 is set to 10 ° C./sec or more and 200 ° C./sec or less, ins-S 700-800 is set to 5 ° C./sec or more and 100 ° C./sec or less, and ins-S 600-700 >. It is necessary to satisfy ins-S 700-800 . When ins-S 700-800 is larger than ins-S 600-700 , the amount of SiO 2 or Fe-based oxide produced is compared with the amount of Mn-containing oxide (brownite or Mn 3 O 4 ) produced. Therefore, the film adhesion cannot be satisfied. The ins-S 600-700 is preferably 1.2 times or more and 20 times or less of the ins-S 700-800 . [0142] 　Further, when ins-S 600-700 is less than 10 ° C./sec , the formation of SiO 2 or Fe-based oxide becomes excessive, and the Mn-containing oxide (brownite or Mn 3 O 4 ) cannot be preferably controlled. Ins-S 600-700 is preferably 40 ° C./sec or higher. Further, in order to suppress overshoot, ins-S 600-700 may be set to 200 ° C./sec. [0143] 　It is also important to control the ins-S 700-800 . In this temperature range, Mn-containing oxides (brownite or Mn 3 O 4 ) are preferentially produced. Therefore, it is necessary to reduce the value of ins-S 700-800 in order to secure the residence time in this temperature range . If ins-S 700-800 exceeds 100 ° C./sec, Mn-containing oxides (brownite or Mn 3 O 4 ) are not sufficiently produced. Ins-S 700-800 is preferably 50 ° C./sec or less. The lower limit of ins-S 700-800 is not particularly limited, but may be 5 ° C./sec from the viewpoint of production. [0144] 　In the insulating film forming step, it is preferable to control the oxygen potential in the atmosphere in addition to the above-mentioned heating rate in the heating process. Specifically, when the temperature of the finished annealed plate is raised, the oxygen potential PH 2 O / PH 2 in the atmosphere in the temperature range of 600 ° C. or higher and 700 ° C. or lower is set to ins-P 600-700, and 700 ° C. or higher and 800 ° C. When the oxygen potential PH 2 O / PH 2 in the atmosphere in the following temperature range is ins-P 700-800 , 　　ins-P 600-700 is 1.0 or more, and 　　ins-P 700-800 is 0. .1 or more and 5.0 or less, and the finish baking plate is raised so that 　　ins-P 600-700 and ins-P 700-800 satisfy ins-P 600-700 > ins-P 700-800. It is preferable to warm it. [0145] 　Although the insulating film is oxidation resistant, the structure may be destroyed in a reducing atmosphere, and the desired tension and film adhesion may not be ensured. Therefore, it is preferable to set the oxygen potential as high as possible in the temperature range of 600 to 700 ° C. where it is considered that the insulating film dries and solidification starts. Therefore, the oxygen potential of ins-P 600-700 is preferably 1.0 or more. [0146] 　On the other hand, in the temperature range of 700 ° C. or higher, a high oxygen potential is unnecessary. Rather, when the temperature is raised with a high oxygen potential such as 5.0 or more, the desired film tension and film adhesion may not be obtained. Although the detailed cause is unknown at this time, the crystallization of the insulating film progresses, grain boundaries are generated, and the annealing gas increases the oxygen potential at the glass film or the glass film / silicon steel plate interface through the grain boundaries. It is considered that oxides having an adverse effect on film adhesion, such as Fe-based oxides, are generated. The oxygen potential in the temperature range of 700 to 800 ° C. is preferably set to a smaller value than the oxygen potential in the temperature range of 600 to 700 ° C. [0147] 　Specifically, after setting ins-P 600-700 to 1.0 or more and ins-P 700-800 to 0.1 or more and 5.0 or less, ins-P 600-700 > ins-P 700. It is preferable to satisfy −800 .　 [0148] 　Since PH 2 O / PH 2 diverges infinitely when annealed in a hydrogen-free atmosphere, the upper limit of the oxygen potential of ins-P 600-700 is not particularly set, but may be set to 100, for example. [0149] 　If ins-P 700-800 exceeds 5.0, SiO 2 or Fe-based oxides may be excessively produced. Therefore, the upper limit of ins-P 700-800 is preferably 5.0. On the other hand, the lower limit of ins-P 700-800 is not particularly limited, and the lower limit may be 0. The lower limit of ins-P 700-800 may be 0.1. [0150] 　When holding or primary cooling at 700 ° C. in the process of raising the temperature to form an insulating film, ins-P 600-700 is based on the time when the temperature reaches 600 ° C. until the start of holding or lowering the temperature at 700 ° C. Similarly, ins-P 700-800 is heated at the end of holding at 700 ° C or after the temperature is lowered, and the temperature is raised again based on the time when the temperature reaches 700 ° C to 800 ° C. Defined as speed. [0151] (2) Holding conditions In the 　insulating film forming step, the holding conditions at the insulating film forming temperature are not particularly limited. Generally, in the holding process for forming the insulating film, holding is performed for 5 seconds or more and 100 seconds or less in a temperature range of 800 ° C. or higher and 1000 ° C. or lower. The holding time is preferably 50 seconds or less. [0152] 　By the above manufacturing method, the unidirectional electromagnetic steel sheet according to the present embodiment can be manufactured. Since the unidirectional electromagnetic steel sheet manufactured by the above manufacturing method contains Mn-containing oxides (particularly brownite or trimanganese tetraoxide) in the glass film, the film adhesion is preferable without impairing the magnetic properties. Improve to. Example 1 [0153] 　Next, the effect of one aspect of the present invention will be described in more detail by way of examples. However, the present invention is not limited to this one-condition example. In the present invention, various conditions can be adopted as long as the gist of the present invention is not deviated and the object of the present invention is achieved. [0154] 　 　Silicon steel slabs (steel pieces) having the composition shown in Tables 1 to 10 are heated to 1280 ° C. or higher and 1450 ° C. or lower and subjected to hot rolling to heat a plate thickness of 2.3 to 2.8 mm. The hot-rolled steel sheet was annealed at 900 to 1200 ° C., and then cold-rolled once or cold-rolled a plurality of times with intermediate annealing in between to obtain a cold-rolled steel sheet with the final thickness. .. This cold-rolled steel sheet was subjected to decarburization annealing in a moist hydrogen atmosphere, and then an annealing separator containing magnesia as a main component was applied and finish annealing was performed to prepare a finish annealing sheet. [0155] 　An insulating film-forming liquid containing colloidal silica and phosphate was applied to the surface of the finished annealed sheet and baked to form an insulating film to prepare a unidirectional electromagnetic steel sheet. Each feature of this unidirectional electrical steel sheet was measured based on the above method. In addition, the film adhesion of the insulating film of the unidirectional electromagnetic steel sheet was evaluated, and the magnetic characteristics (magnetic flux density) were evaluated. [0156] 　The magnetic properties were evaluated according to the Epstein method specified in JIS C 2550-1: 2011. The magnetic flux density was evaluated using B8. B8 is the magnetic flux density in the rolling direction at a magnetic field strength of 800 A / m, and serves as a criterion for determining the quality of secondary recrystallization. When B8 was 1.89T or more, it was judged that the secondary recrystallization proceeded appropriately. [0157] 　The film adhesion of the insulating film was evaluated by the film residual area ratio when the evaluation sample was wound around a cylinder having a diameter of 20 mm and bent by 180 °. The area ratio of the remaining surface of the film to the area of ​​the steel plate in contact with the cylinder was calculated. The area of ​​the steel plate in contact with the roll was calculated. The area of ​​the remaining surface was determined by taking a photograph of the steel sheet after the test and performing image analysis on the photographic image. Excellent when the film residual area ratio is 98% or more, VeryGood (VG) when 95% or more and less than 98%, Good when 90% or more and less than 95%, Fair when 85% or more and less than 90%, 80 The case of% or more and less than 85% was evaluated as Poor, and the case of less than 80% was evaluated as Bad. When the film residual area ratio was 85% or more, it was judged that the adhesion was good. [0158] 　Tables 1 to 40 show the manufacturing conditions, manufacturing results, and evaluation results. In the table, "-" of the chemical component indicates that the alloying element was not intentionally added, or the content is below the lower limit of measurement detection, and "-" other than the chemical component in the table indicates. , Indicates that it has not been implemented. In addition, the values ​​underlined in the table indicate that they are outside the scope of the present invention. [0159] 　In the table, "S1" represents dec-S 500-600 , "S2" represents dec-S 600-700 , "P1" represents dec-P 500-600 , and "P2" represents dec-P. 600-700 represents, "TI" is dec-T I represent, "TII" is dec-T II represents, "tI" is dec-t I represent, "tII" is dec-t II represents, "PI" is dec-P I represents, "PII" is dec-P II represents, "S3" is ins-S 600-700 represent, "S4" is ins-S 700-800 represent, "P3 " Represents ins-P 600-700 , and" P4 "represents ins-P 700-800 . In addition, in the table, "overall oxygen potential control" is defined as dec-P 500-600 > dec-P 600-700. dec-P II indicating whether to satisfy. Further, in the table, "the number ratio of coarse grains in the secondary recrystallized grains" represents the number ratio of the secondary recrystallized grains having a maximum diameter of 30 mm or more and 100 mm or less with respect to all the secondary recrystallized grains. .. Further, in the table, "B" type of "Mn-containing oxides" denotes that it is a browser night, "M" type of "Mn-containing oxides" is Mn 3 O 4 that is Represent. Further, in the table, " Diffraction intensity of I For and I TiN in XRD" indicates whether or not I TiN ins-S 700-800 satisfying, the production method of the grain-oriented electrical steel sheet, characterized in that. [Claim 10] 　And in the decarburization annealing step, dec-P 500-600 and dec-S 600-700 and 　　is, dec-P 500-600 > dec-P 600-700 satisfying, according to claim 9, characterized in that A method for manufacturing a unidirectional electromagnetic steel sheet. [Claim 11] 　And in the decarburization annealing step, 　　the cold-rolled steel sheet after heating subjected to first-stage annealing and the second-stage annealing, 　　the first stage dec-T the holding temperature in units ℃ at annealing I units and to and retention time dec-t I oxygen potential PH of the to and atmosphere 2 O / PH 2 of dec-P I and the dec-T II and and retention time in seconds in dec-t II oxygen potential PH in and atmosphere was 2 O / PH 2 of dec-P II when 　　a, dec-T I is at 900 ° C. or less 700 ° C. or 　　higher, dec-t I is more than 10 seconds 1000 and a 　　sec, dec-P I is 0.10 to 　　1.0, dec-T II is (dec-T I +50) and at 1000 ° C. inclusive ° 　　C., dec-t II is 500 seconds or less than 5 　　seconds, dec-P II is 0.00001 to 0.10 or less, 　　dec-P The method for producing a unidirectional electromagnetic steel plate according to claim 9 or 10, wherein I and dec-P II satisfy dec-P I > dec-P II . [Claim 12] 　And in the decarburization annealing step, dec-P 500-600 and, dec-P 600-700 and, dec-P I and, dec-P II is 　　and, dec-P 500-600 > dec-P 600-700 < The method for producing a unidirectional electromagnetic steel plate according to claim 11, wherein dec-P I > dec-P II is satisfied . [Claim 13] 　In the insulating film forming step, 　　when the temperature of the finished annealed plate is raised, the oxygen potential PH 2 O / PH 2 in the atmosphere in the temperature range of 600 ° C. or higher and 700 ° C. or lower is set to ins-P 600-700 and 700 ° C. When the oxygen potential PH 2 O / PH 2 in the atmosphere in the temperature range of 800 ° C. or lower is ins-P 700-800 , 　　ins-P 600-700 is 1.0 or more, and 　　ins-P 700- 800 is 0.1 to 　　5.0, ins-P 600-700 and ins-P 700-800 and is, ins-P 600-700 > ins-P 700-800 satisfying, and characterized in that The method for manufacturing a unidirectional electromagnetic steel plate according to any one of claims 9 to 12. [Claim 14] 　The one according to any one of claims 9 to 13, wherein in the finishing annealing step, the Ti compound is contained in the annealing separator in an amount of 0.5% by mass or more and 10% by mass or less in terms of metal Ti. Manufacturing method of directional electromagnetic steel plate. [Claim 15] 　As a chemical component, the steel piece contains 　　C: 0.01% or more and 0.20% or less, 　　acid-soluble Al: 0.01% or more and 0.070% or less, and 　　N: 0.0001% or more and 0. 020% or less, 　　S: 0.005% or more and 0.080% or less, 　　Bi: 0.001% or more and 0.020% or less, 　　Sn: 0.005% or more and 0.50% or less, 　　Cr: 0.01% or more The invention according to any one of claims 9 to 14, wherein the mixture 　contains at least one selected from the group consisting of 0.50% or less and 　　Cu: 0.01% or more and 1.0% or less. A method for manufacturing a unidirectional electromagnetic steel sheet.