Title of the invention: Insulation coating composition for electrical steel sheet and electrical steel sheet including insulation coating
Technical field
[One]
It relates to an electrical steel sheet comprising an insulating film composition and an insulating film for an electrical steel sheet. More specifically, it relates to an electrical steel sheet comprising an insulating coating composition and an insulating coating for an electrical steel sheet excellent in heat resistance and thermal conductivity during stress relief annealing using a silane compound containing a specific chemical structure.
Background
[2]
The insulating film of an electrical steel sheet used for a motor or a transformer is required not only for interlayer resistance, but also for various characteristics. For example, it is convenience in processing molding, storage, stability in use, and the like. In addition, since the electrical steel sheet is used for various purposes, various insulating films have been developed according to the application.
[3]
For example, when an electrical steel sheet is subjected to punching, shearing, bending, etc., magnetic properties are deteriorated due to residual deformation. Therefore, in some cases, stress relief annealing (SRA) is performed at high temperatures to restore deteriorated magnetic properties. Therefore, the insulating film is required to have heat resistance properties that do not peel off during stress relief annealing and maintain intrinsic electrical insulation.
[4]
As a previously known insulating coating composition, chromic anhydride, magnesium oxide, acrylic resin, or acrylic-styrene copolymer resin was mixed and applied to improve corrosion resistance and insulation. However, there is a limit to satisfying the heat resistance during stress relief annealing required recently with such an insulating coating composition.
[5]
In addition, a method of improving adhesion during stress relief annealing by using metal phosphate as a main component of the insulating coating composition has been proposed. However, this method has a problem that whitening defects are generated on the surface due to the characteristic of phosphate having strong absorption resistance, and thus dust is generated during product processing, and heat resistance is rather inferior to the area where whitening defects occur.
Detailed description of the invention
Technical challenge
[6]
It provides an electrical steel sheet comprising an insulating coating composition and an insulating coating for electrical steel sheet. More specifically, it provides an electrical steel sheet comprising an insulating film composition and an insulating film for an electrical steel sheet excellent in heat resistance and thermal conductivity during stress relief annealing by using a silane compound containing a specific chemical structure.
Means
[7]
The electrical steel sheet according to an embodiment of the present invention includes an electrical steel sheet substrate and an insulating film located on one or both sides of the electrical steel sheet substrate, and the insulating film includes a silane compound represented by the following formula (1) and a metal hydroxide.
[8]
[Formula 1]
[9]

[10]
(In Formula 1, R 1 and R 2 are each independently hydrogen, a straight or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L is a direct bond. Or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[11]
The silane compound may be represented by the following formula (2).
[12]

[13]
(In Formula 2, R 1 and R 2 are each independently hydrogen, a straight or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L 1 is directly It is a bond or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[14]
Silane compounds include triacetoxy(methyl)silane, triacetoxy(vinyl)silane, and dimethyldimethacroyloxy-1-ethoxysilane. ethoxy)silane) and 3-(trimethoxysilyl)propylmethacrylate.
[15]
Metal hydroxides are Ni(OH) 2 , Co(OH) 2 , Cu(OH) 2 , Sr(OH) 2 , Ba(OH) 2 , Pd(OH) 2 , In(OH) 3 , (CH 3 CO 2 ) 7 Cr 3 (OH) 2 , Bi(OH) 3 and Sn(OH) 2 It may contain one or more of.
[16]
The insulating film may further include a metal nitride, and may include 0.1 to 40% by weight of a metal nitride, 25 to 75% by weight of a silane compound, and 0.5 to 60% by weight of a metal hydroxide.
[17]
The metal nitride may include one or more of BN, AlN, Si 3 N 4 , Mg 3 N 2 , Ca 3 N 2 , Sr 3 N 2 , Ba 3 N 2 , and Ge 3 N 4 .
[18]
The electrical steel sheet may satisfy the following general formula 1.
[19]
[General Formula 1]
[20]
20≤ TC ≤ 200 W/mK
[21]
(In the general formula 1, TC denotes a thermal conductivity value measured by induction heating a 600×400mm specimen at 230° C. and PPMS (Physical Property Measurement System).)
[22]
The electrical steel sheet substrate is C: 0.01% by weight or less, Si: 6.0% by weight or less, P: 0.5% by weight or less, S: 0.005% by weight or less, Mn: 0.1 to 1.0% by weight, Al: 0.40 to 2.0% by weight, N: 0.005% by weight or less, Ti: 0.005% by weight or less, and Sb, Sn, Ni or a combination thereof: 0.01 to 0.15% by weight, and may include Fe and inevitable impurities as the balance.
[23]
The insulating coating composition for an electrical steel sheet according to an embodiment of the present invention includes a silane compound represented by the following Formula 1 and a metal hydroxide.
[24]
[Formula 1]
[25]

[26]
(In Formula 1, R 1 and R 2 are each independently hydrogen, a straight or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L is a direct bond. Or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[27]
A metal nitride may be further included, and, based on a solid content, 0.1 to 40% by weight of a metal nitride, 25 to 75% by weight of a silane compound, and 0.5 to 60% by weight of a metal hydroxide may be included.
[28]
The metal nitride may include one or more of BN, AlN, Si 3 N 4 , Mg 3 N 2 , Ca 3 N 2 , Sr 3 N 2 , Ba 3 N 2 , and Ge 3 N 4 .
[29]
A method of manufacturing an electrical steel sheet according to an embodiment of the present invention includes the steps of preparing a hot-rolled sheet by hot-rolling a slab, undergoing cold rolling, and then preparing a steel sheet having finished final annealing; And applying an insulating film composition to the steel sheet to form an insulating film, wherein the insulating film composition includes a silane compound represented by the following Chemical Formula 1 and a metal hydroxide.
[30]
[Formula 1]
[31]

[32]
(In Formula 1, R 1 and R 2 are each independently hydrogen, a straight or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L is a direct bond. Or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[33]
The electrical steel sheet on which the insulating film is formed may satisfy the following General Formula 1.
[34]
[General Formula 1]
[35]
20≤ TC ≤ 200 W/mK
[36]
(In the above general formula 1, TC represents a thermal conductivity value measured by induction heating a 600x400mm specimen at 230°C and using a PPMS (Physical Property Measurement System).)
[37]
Insulating coating composition for an electrical steel sheet according to an embodiment of the present invention is a silane compound represented by the following formula (1); And at least one chromic acid compound among chromic anhydride, chromate, and dichromate.
[38]
[Formula 1]
[39]

[40]
(In Formula 1, R 1 is hydrogen, a halogen element, a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L is a direct bond or a divalent linking group. M is an integer from 1 to 4, and n is 4-m.)
[41]
Based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound, 10 to 80 parts by weight of the silane compound and 20 to 90 parts by weight of the chromic acid compound may be included.
[42]
In Formula 1, R 1 may be hydrogen, a halogen element, a linear or branched alkyl group or an alkoxy group.
[43]
In Formula 1, L may be a direct bond, an alkylene group, and one or more of -CF 2 -.
[44]
The silane compound may be represented by the following formula (2).
[45]
[Formula 2]
[46]

[47]
(In Formula 2, R 1 to R 3 are each independently hydrogen, a halogen element, a straight or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L 1 Is a direct bond or a divalent linking group, m is an integer from 1 to 4, and n is 4-m.)
[48]
In Formula 2, R 2 and R 3 may each independently be hydrogen or a halogen element.
[49]
Silane compounds include Triethyl (trifluoromethyl) silane (triethyl (trifluoromethyl) silane), Trimethoxy (trifluoropropyl) silane (trimethoxy (trifluoropropyl) silane), and Dimethoxy-methyl (trifluoropropyl) silane (dimethoxy-methyl). (Trifluoropropyl) silane) and Perfluorooctyl-triethoxysilane (perfluorooctyl-triethoxysilane) may be included.
[50]
The ceramic powder may be further included in an amount of 0.5 to 65 parts by weight based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound.
[51]
Ceramic powder is MgO, MnO, Al 2 O 3 , SiO 2 , TiO 2 , Zr0 2 , Al 6 Si 2 O 13 , Al 2 O 3 TiO 2 , Y 2 O 3 , 9Al 2 O 3 B 2 O 3 , BN, CrN, BaTiO 3 It may contain one or more of SiC and TiC.
[52]
The average particle diameter of the ceramic powder may be 0.05 to 20 μm.
[53]
Acrylic resin, styrene resin, vinyl acetate resin, polyester resin, urethane resin, polyethylene resin, polypropylene resin, polyamide resin, polycarbonate resin, phenol resin, alkyd resin, based on 100 parts by weight of the total amount of silane compound and chromic acid compound And 0.5 to 30 parts by weight of one or more polymer resins among the epoxy resins.
[54]
1 to 15 parts by weight of at least one of ethylene glycol, propylene glycol, glycerin, and butyl carbitol based on 100 parts by weight of the silane compound and the chromic acid compound. Can include.
[55]
An electrical steel sheet according to an embodiment of the present invention includes an electrical steel sheet substrate and an insulating film located on one or both sides of the electrical steel sheet substrate.
[56]
The insulating film is a silane compound represented by the following formula (1); And at least one chromic acid compound among chromic anhydride, chromate, and dichromate.
[57]
[Formula 1]
[58]

[59]
(In Formula 1, R 1 is hydrogen, a halogen element, a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L is a direct bond or a divalent linking group. M is an integer from 1 to 4, and n is 4-m.)
[60]
The insulating film contains 0.1 to 50% by weight of Si and 0.01 to 25% by weight of F.
[61]
The thickness of the insulating film may be 0.1 to 10 μm.
[62]
A method of manufacturing an electrical steel sheet according to an embodiment of the present invention includes the steps of manufacturing an electrical steel sheet substrate; And forming an insulating film by applying an insulating film composition to one or both surfaces of an electrical steel substrate.
[63]
The insulating film composition may include a silane compound represented by the following formula (1); And at least one chromic acid compound among chromic anhydride, chromate, and dichromate.
[64]
[Formula 1]
[65]

[66]
(In Formula 1, R 1 is hydrogen, a halogen element, a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L is a direct bond or a divalent linking group. M is an integer from 1 to 4, and n is 4-m.)
[67]
The step of manufacturing the electrical steel sheet base material comprises the steps of manufacturing a hot-rolled sheet by hot rolling the slab; Cold-rolling the hot-rolled sheet may include manufacturing a cold-rolled sheet, and final annealing the cold-rolled sheet.
[68]
The step of forming the insulating film may include heat-treating the steel sheet coated with the insulating film composition at a temperature of 100 to 680°C.
[69]
After the step of forming the insulating film, it may further include a step of stress relief annealing at a temperature of 700 to 1000 ℃.
Effects of the Invention
[70]
According to one embodiment of the present invention, an electrical steel sheet having excellent iron loss characteristics can be obtained after forming an insulating film.
[71]
According to one embodiment of the present invention, it is possible to obtain an electrical steel sheet excellent in the drop ratio.
[72]
According to an embodiment of the present invention, an insulating film having excellent adhesion and peeling resistance can be obtained even after stress relief annealing (SRA).
[73]
According to one embodiment of the present invention, an electrical steel sheet having excellent thermal conductivity can be manufactured, and products such as a motor manufactured using the electrical steel sheet are excellent in efficiency.
Brief description of the drawing
[74]
1 is a schematic view of a cross section of an electrical steel sheet according to an embodiment of the present invention.
[75]
2 is a flow chart of a method of manufacturing an electrical steel sheet according to an embodiment of the present invention.
[76]
3 is a scanning electron microscope (SEM) photograph of a cross section of an electrical steel sheet prepared in Example 1-2.
[77]
4 is a scanning electron microscope (SEM) photograph of a cross section of an electrical steel sheet prepared in Comparative Example 1-2.
[78]
5 is a result of FT-IR-RAS analysis of the electrical steel sheet film prepared in Example 1-2.
[79]
6 is a scanning electron microscope (SEM) photograph of a cross section of an electrical steel sheet prepared in Example 2-2.
[80]
7 is a scanning electron microscope (SEM) photograph of the surface of the electrical steel sheet prepared in Comparative Example 2-3.
Mode for carrying out the invention
[81]
Terms such as first, second and third are used to describe various parts, components, regions, layers and/or sections, but are not limited thereto. These terms are only used to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, a first part, component, region, layer or section described below may be referred to as a second part, component, region, layer or section without departing from the scope of the present invention.
[82]
The terminology used herein is only for referring to specific embodiments and is not intended to limit the present invention. Singular forms as used herein also include plural forms unless the phrases clearly indicate the opposite. The meaning of "comprising" as used in the specification specifies a specific characteristic, region, integer, step, action, element and/or component, and the presence of another characteristic, region, integer, step, action, element and/or component, or It does not exclude additions.
[83]
When a part is referred to as being "on" or "on" another part, it may be directly on or on the other part, or other parts may be involved in between. In contrast, when a part is referred to as being "directly above" another part, no other part is intervened.
[84]
Although not defined differently, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms defined in a commonly used dictionary are additionally interpreted as having a meaning consistent with the related technical literature and the presently disclosed content, and are not interpreted in an ideal or very formal meaning unless defined.
[85]
In the description of a group (atomic group) in the present specification, the notation that does not describe substituted or unsubstituted includes not only having no substituent but also having a substituent. For example, the "alkyl group" includes not only an alkyl group not having a substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
[86]
In the present specification, unless otherwise defined, "substituted" is, at least one hydrogen in the compound is a C1 to C30 alkyl group; C2 to C30 alkenyl group, C2 to C30 alkynyl group, C1 to C10 alkylsilyl group; C3 to C30 cycloalkyl group; C6 to C30 aryl group; C1 to C30 heteroaryl group; C1 to C10 alkoxy group; Silane group; Alkylsilane group; Alkoxysilane group; Amine group; Alkylamine group; Arylamine group; It means substituted with an ethyleneoxyl group or a halogen group.
[87]
In the present specification, unless otherwise defined, "hetero" means an atom selected from the group consisting of N, O, S, and P.
[88]
In the present specification, the term "alkyl group" is a "saturated alkyl group" that does not contain any alkenyl group or alkynyl group, unless otherwise defined; Or it means including all of the "unsaturated alkyl group" including at least one alkenyl group or an alkynyl group. The "alkenyl group" refers to a substituent in which at least two carbon atoms form at least one carbon-carbon double bond, and the "alkyne group" refers to a substituent in which at least two carbon atoms form at least one carbon-carbon triple bond. it means. The alkyl group may be branched, straight or cyclic.
[89]
The alkyl group may be a C1 to C20 alkyl group, and specifically, a C1 to C6 lower alkyl group, a C7 to C10 intermediate alkyl group, and a C11 to C20 higher alkyl group.
[90]
For example, a C1 to C4 alkyl group means the presence of 1 to 4 carbon atoms in the alkyl chain, which is methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl and t-butyl. It indicates that it is selected from the group consisting of.
[91]
Typical alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, ethenyl group, propenyl group, butenyl group, cyclopropyl group, cyclobutyl group, cyclo And a pentyl group and a cyclohexyl group.
[92]
"Aromatic group" means a substituent in which all elements of a cyclic substituent have a p-orbital, and these p-orbitals form a conjugation. Specific examples include an aryl group and a heteroaryl group.
[93]
"Aryl group" includes a single ring or a fused ring, ie, a plurality of ring substituents that share adjacent pairs of carbon atoms.
[94]
"Heteroaryl group" means an aryl group in which a hetero atom selected from the group consisting of N, O, S, and P is included in the aryl group. When the heteroaryl group is a fused ring, each ring may contain 1 to 3 heteroatoms.
[95]
Unless otherwise defined herein, an alkyl group, cycloalkyl group, alkenyl group, alkynyl group, aryl group, heteroaryl group, alkoxy group, or aminoalkyl group is a substituted or unsubstituted alkyl group, cycloalkyl group, alkenyl group, alkynyl group, It means an aryl group, a heteroaryl group, an alkoxy group, or an aminoalkyl group.
[96]
Unless otherwise defined herein, a divalent linking group refers to 1 selected from an alkylene group, an alkenylene group, an arylene group, -NR'-, -O-, -SO 2 -, -CO-, -CF 2- It means a divalent linking group of more than a species. R'is an alkyl group.
[97]
Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art may easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.
[98]
Insulation coating composition for electrical steel sheet
[99]
The insulating coating composition for an electrical steel sheet according to an embodiment of the present invention includes a silane compound represented by the following Formula 1 and a metal hydroxide.
[100]
[Formula 1]
[101]

[102]
(In Formula 1, R 1 and R 2 are each independently hydrogen, a straight or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L is a direct bond. Or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[103]
The insulating coating composition according to an embodiment of the present invention includes a silane compound having a unique chemical structure in order to remarkably improve the heat resistance and corrosion resistance of stress relief annealing. In addition, when the silane compound is used alone, there is a problem that the film is peeled off during the stress relief annealing process and it is difficult to uniformly apply it to the surface of the electrical steel sheet. It also includes metal hydroxides to improve this.
[104]
Hereinafter, an insulating coating composition for an electrical steel sheet according to an embodiment of the present invention will be described in detail for each component.
[105]
First, the insulating coating composition for an electrical steel sheet according to an embodiment of the present invention includes a silane compound represented by Formula 1 on a solid basis. Specifically, it may contain 30 to 75 parts by weight based on 100 parts by weight of the total amount of the silane compound and metal hydroxide.
[106]
The silane compound represented by Formula 1 contains a Si element and a carbonyl group in the compound, so it has excellent heat resistance. In addition, the carbonyl group is excellent in reactivity with the metal hydroxide, and thus plays an important role in forming a silane compound-metal hydroxide complex and remarkably improving the surface quality.
[107]
Specifically, the silane compound may be represented by the following formula (2).
[108]
[Formula 2]
[109]

[110]
(In Formula 2, R 1 and R 2 are each independently hydrogen, a straight or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L 1 is directly It is a bond or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[111]
Specifically, in Formulas 1 and 2, R 1 and R 2 may be hydrogen or an alkyl group. More specifically, R 1 and R 2 may be a methyl group or an ethyl group.
[112]
Specifically, in Formula 1, L may be at least one divalent linking group selected from an alkylene group, -O-, and -CO-. More specifically, in Formula 1, L may be represented by -L 1 -O-, and L 1 may be a direct bond or at least one divalent linking group selected from an alkylene group, -O-, and -CO-.
[113]
Silane compounds include triacetoxy(methyl)silane, triacetoxy(vinyl)silane, and dimethyldimethacroyloxy-1-ethoxysilane. ethoxy)silane) and 3-(trimethoxysilyl)propylmethacrylate.
[114]
If too little of the silane compound is contained, heat resistance may be lowered, resulting in heat loss after stress relief annealing. If too much of the silane compound is included, the metal hydroxide is relatively small, and the film may be peeled off. Therefore, the silane compound may be included in the above-described range. More specifically, the silane compound may be included in an amount of 40 to 55 parts by weight based on 100 parts by weight of the total amount of the silane compound and the metal hydroxide.
[115]
The insulating coating composition for an electrical steel sheet according to an embodiment of the present invention includes a metal hydroxide. Specifically, it contains 25 to 70 parts by weight of metal hydroxide based on 100 parts by weight of the total amount of the silane compound and the metal hydroxide.
[116]
Metal hydroxide is characterized by being well dispersed in a solvent, and plays a role in changing the surface property from hydrophobic to hydrophilic so that it can be well dispersed in the solvent through a chemical reaction with the functional group of the silane compound. Since such metal hydroxide is uniformly applied to the surface of the electrical steel sheet, it is of great help in remarkably improving heat resistance and corrosion resistance during stress relief annealing of the insulating film.
[117]
The metal hydroxide can be used without limitation as long as it is a metal containing a hydroxyl group (-OH). Specifically, the metal hydroxide is Ni(OH) 2 , Co(OH) 2 , Cu(OH) 2 , Sr(OH) 2 , Ba(OH) 2 , Pd(OH) 2 , In(OH) 3 , (CH 3 CO 2 ) 7 Cr 3 (OH) 2 , Bi(OH) 3 and Sn(OH) 2 It may contain one or more of. More specifically, Co(OH) 2 and (CH 3 CO 2 ) 7 Cr 3 (OH) 2 It may contain one or more of.
[118]
If too little metal hydroxide is included, a problem may occur in dispersion of the silane compound, and uniform application may be difficult. When too much metal hydroxide is included, the silane compound is relatively small, so that improvement in heat resistance and corrosion resistance during stress relief annealing may be insufficient. More specifically, 45 to 60 parts by weight of metal hydroxide may be included based on 100 parts by weight of the total amount of the silane compound and the metal hydroxide.
[119]
The insulating coating composition for an electrical steel sheet according to an embodiment of the present invention may further include a metal nitride in addition to a silane compound and a metal hydroxide. When an appropriate amount of metal nitride is further included, insulating properties and thermal conductivity properties of the formed insulating film may be further improved.
[120]
When a metal nitride is further included, 0.1 to 40% by weight of a metal nitride, 25 to 75% by weight of a silane compound, and 0.5 to 60% by weight of a metal hydroxide may be included on a solid basis.
[121]
The solid content means that the solid portion excluding volatile components such as solvents in the insulating coating composition is based on 100% by weight.
[122]
If too little metal nitride is added, the effect of improving the insulating properties and the thermal conductivity properties may be insufficient. If too much metal nitride is included, the amount of the silane compound and the metal hydroxide are relatively small, and thus, improvement in heat resistance and corrosion resistance during stress relief annealing may be insufficient. More specifically, based on solid content, 1 to 25% by weight of a metal nitride, 35 to 65% by weight of a silane compound, and 15 to 50% by weight of a metal hydroxide may be included.
[123]
The metal nitride may include one or more of BN, AlN, Si 3 N 4 , Mg 3 N 2 , Ca 3 N 2 , Sr 3 N 2 , Ba 3 N 2 , and Ge 3 N 4 .
[124]
The average particle diameter of the metal nitride may be 0.05 to 20 μm. When the particle size of the metal nitride is appropriate, dispersibility and coating property are easy.
[125]
Insulation coating composition for electrical steel sheet according to an embodiment of the present invention is one or more of ethylene glycol (Ethylene golycol), propylene glycol (Propylene glycol), glycerin (Glycerine), butyl carbitol (Butyl carbitol) in addition to the silane compound and metal nitride. It may further include. By further including the above-described additives, it is possible to form an insulating film having excellent surface gloss and very beautiful roughness. The above-described additive may be further included in 1 to 15 parts by weight based on 100 parts by weight of the total amount of the silane compound and metal hydroxide. If too little of the additive is included, the above-described enhancement effect may be insufficient. Even if the additive is further included, there is no further improvement effect, and the dispersibility may be inferior. More specifically, the additive may be included in 3 to 10 parts by weight based on 100 parts by weight of the total amount of the silane compound and the metal hydroxide.
[126]
The insulating coating composition may further include a solvent for even dispersion and easy application of solids. Water, alcohol, etc. may be used as the solvent, and may contain 300 to 1000 parts by weight based on 100 parts by weight of the total amount of the silane compound and the metal hydroxide. As such, the insulating coating composition may be in the form of a slurry.
[127]
Insulating coating composition for an electrical steel sheet according to an embodiment of the present invention is a silane compound represented by the following formula (1); And at least one chromic acid compound selected from chromic anhydride, chromate, and dichromate.
[128]
[Formula 1]
[129]

[130]
(In Formula 1, R 1 is hydrogen, a halogen element, a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L is a direct bond or a divalent linking group. M is an integer from 1 to 4, and n is 4-m.)
[131]
The insulating coating composition according to an embodiment of the present invention includes a silane compound having a unique chemical structure in order to remarkably improve the heat resistance and corrosion resistance of stress relief annealing. In addition, when the silane compound is used alone, there is a problem that the film is peeled off during the stress relief annealing process and it is difficult to uniformly apply it to the surface of the electrical steel sheet. It also includes chromic acid compounds to improve this.
[132]
Hereinafter, an insulating coating composition for an electrical steel sheet according to an embodiment of the present invention will be described in detail for each component.
[133]
First, the insulating coating composition for an electrical steel sheet according to an embodiment of the present invention includes a silane compound represented by Chemical Formula 1.
[134]
The silane compound represented by Formula 1 contains Si elements and F elements in the compound, and thus has extremely excellent heat resistance. In particular, F element has the effect of suppressing chemical reactions in which moisture in the air penetrates into the insulating film, so it has excellent chemical resistance, insulation, and corrosion resistance, and plays an important role in remarkably improving the surface quality of the electrical steel sheet.
[135]
The silane compound may be included in an amount of 10 to 80 parts by weight based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound.
[136]
If too little of the silane compound is included, the content of Si and F elements in the insulating film to be formed decreases, resulting in lower heat resistance, which may lead to heat loss after stress relief annealing. It may be difficult to form a uniform insulating film due to poor compatibility with a solvent. Therefore, the silane compound may be included in the above-described range. More specifically, 40 to 70 parts by weight of the silane compound may be included.
[137]
In Formula 1, R 1 may be hydrogen, a halogen element, a linear or branched alkyl group or an alkoxy group. When m is 2 or more, a plurality of R 1s may be the same as or different from each other.
[138]
In Formula 1, L may be a direct bond, an alkylene group, and one or more of -CF 2 -. When n is 2 or more, a plurality of L may be the same as or different from each other.
[139]
Specifically, the silane compound may be represented by the following formula (2).
[140]
[Formula 2]
[141]

[142]
(In Formula 2, R 1 to R 3 are each independently hydrogen, a halogen element, a straight or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L 1 Is a direct bond or a divalent linking group, m is an integer from 1 to 4, and n is 4-m.)
[143]
Specifically, in Formula 2, R 1 , m, and n are the same as those of Formula 1.
[144]
L 1 may be a direct bond or a divalent linking group. More specifically, L 1 may be a direct bond, an alkylene group, and one or more of -CF 2 -.
[145]
R 2 and R 3 may each independently be hydrogen or a halogen element.
[146]
Silane compounds include Triethyl (trifluoromethyl) silane (triethyl (trifluoromethyl) silane), Trimethoxy (trifluoropropyl) silane (trimethoxy (trifluoropropyl) silane), and Dimethoxy-methyl (trifluoropropyl) silane (dimethoxy-methyl). (Trifluoropropyl) silane) and Perfluorooctyl-triethoxysilane (perfluorooctyl-triethoxysilane).
[147]
More specifically, the silane compound is Triethyl (trifluoromethyl) silane, Trimethoxy (3,3,3-trifluoropropyl) silane, Dimethoxy-methyl (3,3,3-trifluoropropyl) silane and 1H,1H,2H,2H-Perfluorooctyl-triethoxysilane It may contain one or more of.
[148]
The insulating coating composition for an electrical steel sheet according to an embodiment of the present invention includes at least one chromic acid compound selected from chromic anhydride, chromate, and dichromate.
[149]
The chromic acid compound chemically reacts with the silane compound to improve dispersion stability, thereby forming a uniform film. In addition, the chromic acid compound has an effect of reducing cost when mass-produced and has the advantage of being able to operate stably in an insulating coating process.
[150]
As the chromate and dichromate, salts such as Na, K, Mg, Ca, Mn, Mo, Zn, Al can be used, for example.
[151]
Based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound, 20 to 90 parts by weight of the chromic acid compound may be included. If too little of the chromic acid compound is included, a problem may occur in dispersing the silane compound, making it difficult to uniformly apply. When too much of the chromic acid compound is included, the silane compound is relatively small, so that improvement in heat resistance and corrosion resistance during stress relief annealing may be insufficient. More specifically, the chromic acid compound may be included in an amount of 30 to 60 parts by weight.
[152]
The insulating coating composition for an electrical steel sheet according to an embodiment of the present invention may further include ceramic powder in addition to the silane compound and the chromic acid compound. When an appropriate amount of ceramic powder is further included, the insulating properties of the formed insulating film may be further improved.
[153]
The ceramic powder may be included in 0.5 to 65 parts by weight based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound. If too little ceramic powder is included, the effect of improving the insulating properties may be insufficient. If too much ceramic powder is included, the amounts of the silane compound and the chromic acid compound are relatively small, so that improvement in heat resistance and corrosion resistance during stress relief annealing may be insufficient. More specifically, the ceramic powder may be included in 5 to 30 parts by weight based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound.
[154]
Ceramic powder is MgO, MnO, Al 2 O 3 , SiO 2 , TiO 2 , ZrO 2 , Al 6 Si 2 O 13 , Al 2 O 3 · TiO 2 , Y 2 O 3 , 9Al 2 O 3 · B 2 O 3 , BN, CrN, BaTiO 3 It may contain one or more of SiC and TiC. More specifically, the ceramic powder is MgO, CaO, Al 2 O 3 , SiO 2, TiO 2 , ZrO 2 , Al 2 O 3 TiO 2 , Y 2 O 3 , 9Al 2 O 3 B 2 O 3 , BN, CrN, BaTiO 3 , SiC and TiC may contain one or more of
[155]
The average particle diameter of the ceramic powder may be 0.05 to 20 μm. When the particle diameter of the ceramic powder is appropriate, dispersibility and coating property are easy.
[156]
The insulating coating composition for an electrical steel sheet according to an embodiment of the present invention is acrylic resin, styrene resin, vinyl acetate resin, polyester resin, urethane resin, polyethylene resin, polypropylene resin based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound. , A polyamide resin, a polycarbonate resin, a phenol resin, an alkyd resin, and an epoxy resin of 0.5 to 30 parts by weight of at least one polymer resin may further be included. By adding an appropriate amount of the above-described polymer resin, an electrical steel sheet having excellent surface gloss and very beautiful roughness can be manufactured.
[157]
The insulating coating composition for an electrical steel sheet according to an embodiment of the present invention is based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound, ethylene glycol (Ethylene golycol), propylene glycol (Propylene glycol), glycerin (Glycerine), butyl carbitol ( Butyl carbitol) may further contain 1 to 15 parts by weight of one or more. By further including the above-described additives, it is possible to form an insulating film having excellent surface gloss and very beautiful roughness. If too little of the additive is included, the above-described enhancement effect may be insufficient. Even if the additive is further included, there is no further improvement effect, and the dispersibility may be inferior. More specifically, the additive may be included in 3 to 10 parts by weight based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound.
[158]
The insulating coating composition may further include a solvent for even dispersion and easy application of solids. Water, alcohol, etc. may be used as the solvent, and may include 300 to 1000 parts by weight based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound. As such, the insulating coating composition may be in the form of a slurry.
[159]
Electric steel sheet
[160]
The electrical steel sheet 100 according to an embodiment of the present invention includes an electrical steel sheet substrate 10 and an insulating film 20 located on one or both sides of the electrical steel sheet substrate 10. 1 shows a schematic side cross-sectional view of an electrical steel sheet according to an embodiment of the present invention. 1 shows a case in which an insulating film 20 is formed on the upper surface of the electrical steel plate substrate 10.
[161]
The insulating film 20 includes a silane compound and a metal hydroxide represented by Formula 1 below.
[162]
[Formula 1]
[163]

[164]
(In Formula 1, R 1 and R 2 are each independently hydrogen, a straight or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L is a direct bond. Or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[165]
The insulating film 20 of the electrical steel sheet 100 according to an embodiment of the present invention includes a silane compound having a unique chemical structure in order to significantly improve the stress relief annealing heat resistance and corrosion resistance, and also improve thermal conductivity. In addition, when the silane compound is used alone, there is a problem that the film is peeled off during the stress relief annealing process and it is difficult to uniformly apply it to the surface of the electrical steel sheet. It also includes metal hydroxides to improve this.
[166]
Since the content of the components of the insulating film 20 has been described in detail with respect to the above-described insulating film composition, a redundant description will be omitted. In the process of forming the insulating film 20, the chemical structure of some silane compounds may be modified, but most of the silane compounds retain their chemical structure. In addition, in the process of forming the insulating film 20, a silane compound and a metal hydroxide may react to form a compound. In this case, the ratio of the silane compound and the content of metal hydroxide in the compound are calculated, and the silane compound and the metal hydroxide are respectively It is calculated by the weight of. Since volatile components such as a solvent are removed in the process of forming the insulating film 20, the components in the insulating film 20 are substantially the same as the solid component in the insulating film composition.
[167]
The insulating film 20 may contain 0.1 to 50% by weight of Si. In this case, Si may be Si in the silane compound, Si in the metal nitride, or Si diffused from the electrical steel sheet substrate 10 when Si 3 N 4 is used as the metal nitride. Si is included in an appropriate amount, so that the insulating properties of the insulating film 20 can be secured.
[168]
In addition to Si, the insulating film 20 may include an insulating film composition such as Fe, C, and O, and an element derived from the electrical steel plate substrate 10.
[169]
The thickness of the insulating film 20 may be 0.1 to 10 μm. If the thickness of the insulating film 20 is too thin, heat resistance may be lowered, resulting in a problem of heat loss after stress relief annealing. If the thickness of the insulating film 20 is too thick, a drop ratio may be lowered, resulting in a problem of deteriorating motor characteristics. Accordingly, the thickness of the insulating film 20 can be adjusted within the above-described range. More specifically, the thickness of the insulating film 20 may be 0.2 to 5 μm.
[170]
The electrical steel plate substrate 10 may be used without limitation of a non-oriented electrical steel sheet or a grain-oriented electrical steel sheet. Specifically, a non-oriented electrical steel sheet can be used. In one embodiment of the present invention, insulating properties are generated by the components of the insulating film 20, and may be irrelevant to the alloy components of the electrical steel sheet. Hereinafter, as an example, an alloy component of the electrical steel sheet will be described.
[171]
Electrical steel sheet C: 0.01% by weight or less, Si: 6.0% by weight or less, P: 0.5% by weight or less, S: 0.005% by weight or less, Mn: 0.1 to 1.0% by weight, Al: 0.40 to 2.0% by weight, N: 0.005 Wt% or less, Ti: 0.005 wt% or less, and Sb, Sn, Ni or a combination thereof: 0.01 to 0.15 wt%, and may include Fe and inevitable impurities as the balance.
[172]
Hereinafter, it will be described in detail for each alloy component.
[173]
Hereinafter, the reasons for limiting the components of the non-oriented electrical steel sheet substrate 10 will be described.
[174]
C: 0.01% by weight or less
[175]
Carbon (C) is a component that is not very helpful in improving the magnetic properties of the electrical steel sheet in the embodiment according to the present invention, so it is preferable to remove it as much as possible. C is contained in less than 0.01% by weight as it causes magnetic aging in the final product and lowers the magnetic properties during use, and the lower the content of C is, the more desirable it is for magnetic properties. Do.
[176]
Si: 6.0% by weight or less
[177]
Silicon (Si) is a component that decreases eddy current loss during iron loss by increasing the specific resistance of steel, and when the content of Si is too large, brittleness increases and cold rolling may become difficult. Therefore, it is preferable to limit it to 6.0% by weight or less. More specifically, Si may be included in an amount of 0.1 to 4.0% by weight.
[178]
P: 0.5% by weight or less
[179]
Phosphorus (P) is added to increase the specific resistance, improve the texture, and improve the magnetism. If it is added excessively, it is preferable to limit it to 0.5% by weight or less because cold rolling property deteriorates.
[180]
S: 0.005% by weight or less
[181]
Since sulfur (S) forms fine precipitates of MnS and CuS and deteriorates magnetic properties by suppressing crystal grain growth, it is preferable to manage as low as possible, and the content thereof is limited to 0.005% by weight or less.
[182]
Mn: 0.1 to 1.0% by weight
[183]
If manganese (Mn) is present in an amount of less than 0.1% by weight, fine MnS precipitates are formed to inhibit crystal grain growth, thereby deteriorating the magnetism. Therefore, when present in an amount of 0.1% by weight or more, coarse MnS is formed, and the S component can be prevented from being precipitated as CuS, which is a finer precipitate. However, since the magnetism deteriorates when Mn is increased, it is added at 1.0% by weight or less.
[184]
Al: 0.40 to 2.0% by weight
[185]
Al is an effective component in reducing eddy current loss by increasing the specific resistance. When the content is less than 0.40% by weight, AlN is finely precipitated and magnetic property is inferior, and when it exceeds 2.0% by weight, workability is deteriorated.
[186]
N: 0.005% by weight or less
[187]
N is contained in a small amount because it suppresses grain growth by forming fine and long AlN precipitates inside the base material, and is preferably limited to 0.005% by weight or less.
[188]
Ti: 0.005% by weight or less
[189]
Ti forms fine precipitates of TiN and TiC to suppress crystal grain growth, and when added in excess of 0.005% by weight, many fine precipitates are generated, deteriorating the texture and deteriorating magnetism.
[190]
Sb, Sn, Ni, or a combination thereof: 0.01 to 0.15% by weight
[191]
Sb, Sn, or Ni is a surface precipitation element that is concentrated on the surface layer of the steel plate to suppress the adsorption of nitrogen and, as a result, does not interfere with the growth of crystal grains, thereby lowering the iron loss. If one content is too small, there may be a problem that the effect is reduced. If the amount of Sb, Sn, or Ni added alone or in combination is too large, grain boundary segregation occurs severely, resulting in increased brittleness of the steel sheet, which may lead to sheet fracture during rolling. When two or more types of Sb, Sn, and Ni are added in combination, the total amount may be 0.01 to 0.15% by weight.
[192]
More specifically, 0.01 to 0.05% by weight of Sb, 0.01 to 0.12% by weight of Sn, and 0.01 to 0.06% by weight of Ni may be included.
[193]
As described above, the electrical steel sheet according to an embodiment of the present invention has excellent thermal conductivity due to the formation of an insulating film. Specifically, the following general formula 1 may be satisfied.
[194]
[General Formula 1]
[195]
20≤ TC ≤ 200 W/mK
[196]
(In the above general formula 1, TC represents a thermal conductivity value measured by induction heating a 600x400mm specimen at 230°C and using a PPMS (Physical Property Measurement System).)
[197]
The insulating film 20 of the electrical steel sheet 100 according to an embodiment of the present invention includes a silane compound having a unique chemical structure in order to significantly improve heat resistance and corrosion resistance for stress relief annealing. In addition, when the silane compound is used alone, there is a problem that the film is peeled off during the stress relief annealing process and it is difficult to uniformly apply it to the surface of the electrical steel sheet. It also includes chromic acid compounds to improve this.
[198]
Since the content of the components of the insulating film 20 has been described in detail with respect to the above-described insulating film composition, a redundant description will be omitted. In the process of forming the insulating film 20, the chemical structure of some silane compounds may be modified, but most of the silane compounds retain their chemical structure. In addition, in the process of forming the insulating film 20, a silane compound and a chromic acid compound may react to form a compound. In this case, the ratio of the silane compound and the content ratio of the chromic acid compound in the compound are calculated, and the silane compound and the chromic acid compound are respectively It is calculated by the weight of. Since volatile components such as a solvent are removed in the process of forming the insulating film 20, the components in the insulating film 20 are substantially the same as the solid component in the insulating film composition. The solid content means that the solid portion excluding volatile components such as solvents in the insulating coating composition is based on 100% by weight.
[199]
The insulating film 20 may contain 0.1 to 50% by weight of Si and 0.01 to 25% by weight of F. In this case, Si may be Si in the silane compound, Si in the ceramic powder when SiO 2 is used as the ceramic powder, or Si diffused from the electrical steel sheet substrate 10. Si is included in an appropriate amount, so that the insulating properties of the insulating film 20 can be secured.
[200]
In addition, F can be derived from F in the silane compound. When F is contained in an appropriate amount, chemical resistance, insulation, and corrosion resistance of the insulating film 20 can be improved.
[201]
In addition to Si and F, the insulating film 20 may include an insulating film composition such as Cr, Fe, C, O, and an element derived from the electrical steel plate substrate 10.
[202]
The thickness of the insulating film 20 may be 0.1 to 10 μm. If the thickness of the insulating film 20 is too thin, heat resistance may be lowered, resulting in a problem of heat loss after stress relief annealing. If the thickness of the insulating film 20 is too thick, a drop ratio may be lowered, resulting in a problem of deteriorating motor characteristics. Accordingly, the thickness of the insulating film 20 can be adjusted within the above-described range. More specifically, the thickness of the insulating film 20 may be 0.2 to 5 μm.
[203]
Manufacturing method of electrical steel sheet
[204]
2 schematically shows a flow chart of a method for manufacturing an electrical steel sheet according to an embodiment of the present invention. The flow chart of the method of manufacturing the electrical steel sheet of FIG. 2 is for illustrative purposes only, and the present invention is not limited thereto. Therefore, the manufacturing method of the electrical steel sheet can be variously modified.
[205]
As shown in Figure 2, the method of manufacturing an electrical steel sheet comprises the steps of manufacturing an electrical steel sheet substrate (S10); And forming an insulating film by applying an insulating film composition to one or both surfaces of an electrical steel substrate (S20). In addition, the manufacturing method of the electrical steel sheet may further include other steps.
[206]
First, in step S10, an electrical steel plate substrate is manufactured. Since the alloy components of the electrical steel sheet have been described in detail, repeated descriptions are omitted.
[207]
The step of manufacturing the electrical steel sheet base material comprises the steps of manufacturing a hot-rolled sheet by hot rolling the slab; Cold-rolling the hot-rolled sheet may include manufacturing a cold-rolled sheet, and final annealing the cold-rolled sheet.
[208]
First, the slab is heated. At this time, the slab heating can be heated below 1,200 ℃.
[209]
Next, the heated slab is hot-rolled to manufacture a hot-rolled sheet. The manufactured hot-rolled sheet can be hot-rolled and annealed.
[210]
Next, the hot-rolled sheet is cold-rolled to manufacture a cold-rolled sheet. Cold rolling may be performed once, or two or more cold rolling including intermediate annealing may be performed.
[211]
Next, the cold-rolled sheet is finally annealed. At this time, in the final annealing step of the cold-rolled sheet, the rolling oil present in the cold-rolled sheet is degreased, primary annealing may be performed, and secondary annealing may be performed in an atmosphere composed of hydrogen and nitrogen. In addition, in the final annealing, the dew point temperature may be controlled to be -5°C or less for the purpose of preventing magnetism from deteriorating due to the formation of oxides on the surface.
[212]
Returning to the description of the method of manufacturing the electrical steel sheet again, the next step (S20) is to form an insulating film by applying an insulating film composition to one or both surfaces of the electrical steel sheet substrate. Since the insulating coating composition is the same as described above, a duplicate description will be omitted.
[213]
The step of forming the insulating film may include heat-treating the steel sheet coated with the insulating film composition at a temperature of 100 to 680°C. If the heat treatment temperature is too low, it is difficult to remove the solvent, and it is difficult to form a beautiful insulating film. If the heat treatment temperature is too high, a problem of poor adhesion may occur. More specifically, it may be heat-treated at a temperature of 350 to 650°C. The heat treatment time may be 5 to 200 seconds.
[214]
After the step of forming the insulating film, it may further include a step of stress relief annealing at a temperature of 700 to 1000 ℃. In an embodiment of the present invention, even after stress relief annealing by a silane compound and a metal hydroxide in the insulating film composition, it is possible to maintain excellent adhesion and surface properties of the insulating film. If the temperature of the stress relief annealing is too low, the desired stress removal may not be performed smoothly. If the temperature of the stress relief annealing is too high, the magnetism of the electrical steel sheet may be inferior.
[215]
The step of stress relief annealing may be performed in a nitrogen atmosphere, and may be performed for 1 to 5 hours.
[216]
Hereinafter, the present invention will be described in more detail through examples. However, these examples are for illustrative purposes only, and the present invention is not limited thereto.
[217]
Experimental Example 1-1: Characteristics of each type of silane compound
[218]
Example 1-1
[219]
3.4% by weight of silicon (Si), aluminum (Al): 0.80% by weight, manganese (Mn): 0.17% by weight titanium (Ti): 0.0015% by weight, tin (Sn): 0.03% by weight, nickel (Ni): 0.01 % By weight, carbon (C): 0.003% by weight, nitrogen (N): 0.0013% by weight, phosphorus (P): 0.012% by weight, sulfur (S): 0.001% by weight, the balance consisting of Fe and other inevitable impurities The slab was prepared.
[220]
The slab was heated at 1130° C. and then hot-rolled to a thickness of 2.3 mm to prepare a hot-rolled sheet.
[221]
The hot-rolled sheet was wound at 650°C, cooled in air, and then annealed at 1040°C for 2 minutes, quenched in water, pickled, and then cold-rolled to a thickness of 0.35mm to prepare a cold-rolled sheet.
[222]
The cold-rolled sheet was subjected to final annealing by adjusting the dew point temperature in an atmosphere of 20% hydrogen and 80% nitrogen for 50 seconds at 1040°C, thereby producing an annealed steel sheet.
[223]
As an insulating coating composition, triacetoxymethylsilane 60 parts by weight, nickel hydroxide (Ni(OH) 2 ) 20 parts by weight, strontium hydroxide (Sr(OH) 2 ) 10 parts by weight, boron nitride 5 parts by weight, and ethylene glycol 5 parts by weight It was mixed with distilled water to prepare a slurry form, and the slurry was applied to the final annealed steel sheet using a roll, and then heat-treated at 650°C for 30 seconds and cooled in air. The electrical steel sheet was subjected to stress relief annealing (SRA, Stress Relief Annealing) for 2 hours at 750°C in a 100% nitrogen atmosphere, and then cooled in air. The thickness of the insulating film was about 0.8 µm.
[224]
Examples 1-2 to 1-12
[225]
In the same manner as in Example 1-1, the contents and types of the silane compound, metal hydroxide, and metal nitride in the insulating film composition were replaced as shown in Table 1 below to form an insulating film.
[226]
Comparative Example 1-1
[227]
In the same manner as in Example 1-1, but without metal hydroxide, an insulating coating composition containing 100 parts by weight of triacetoxymethylsilane was used.
[228]
Comparative Example 1-2
[229]
In the same manner as in Example 1-1, but without a silane compound, an insulating coating composition containing 100 parts by weight of chromium hydroxide was used.
[230]
Comparative Example 1-3
[231]
In the same manner as in Example 1-1, but without a silane compound, an insulating coating composition containing 60 parts by weight of chromium hydroxide and 40 parts by weight of boron nitride was used.
[232]
The properties of the electrical steel sheets prepared in Examples and Comparative Examples were measured and summarized in Table 2 below.
[233]
The iron loss (W 15/50 ) means the power loss that occurs when a magnetic field with a frequency of 50 Hz is magnetized to 1.5 Tesla by alternating current.
[234]
In addition, the insulating properties were measured on the upper part of the insulating film using a Franklin measuring device according to ASTM A717 international standard.
[235]
In addition, the adhesion is expressed as the minimum arc diameter without film peeling when the specimen is bent 180° in contact with a 10 to 100 mm arc.
[236]
In addition, the surface feature is a result of visually evaluating the degree of uniformity of color and formation of a uniform film.
[237]
In addition, the thermal conductivity was measured by induction heating the electrical steel sheet at 230°C and the thermal conductivity of the specimen by PPMS (Physical property measurement system, manufactured by Quantum Design).
[238]
[Table 1]
[239]

[240]
[Table 2]
[241]
As shown in Tables 1 and 2, it can be seen that the insulating film properties of the examples are superior to those of the comparative examples. In addition, when a silane compound or a metal hydroxide is included alone, it can be confirmed that film peeling occurs severely and magnetic properties are deteriorated.
[242]
3 and 4 show a scanning electron microscope (SEM) photograph of a cross section of an electrical steel sheet prepared in Example 1-2 and Comparative Example 1-2, respectively. As shown in FIG. 3, in the case of Example 1-2, it can be seen that the beautiful insulating film is maintained even after the SRA. On the other hand, as shown in FIG. 4, in the case of Comparative Example 1-2, it can be confirmed that a number of cracks occur on the surface of the insulating film after SRA.
[243]
5 shows the results of FT-IR-RAS analysis of the electrical steel sheet film prepared in Example 1-2. As can be seen in FIG. 5, it can be seen that triacetoxyvinylsilane is present in the film.
[244]
Experimental Example 1-2: Evaluation of dot ratio
[245]
Example 1-13
[246]
Silicon (Si) 4.2 wt%, Aluminum (Al): 0.80 wt%, Manganese (Mn): 0.15 wt% Titanium (Ti) 0.001 wt%, Tin (Sn) 0.08 wt%, Carbon (C) 0.004 Slabs were prepared containing 0.0015% by weight of nitrogen (N), 0.015% by weight of phosphorus (P), and 0.001% by weight of sulfur (S), the balance being Fe and other inevitable impurities.
[247]
The slab was heated at 1150° C. and then hot-rolled to a thickness of 2.3 mm to prepare a hot-rolled sheet.
[248]
The hot-rolled sheet was wound at 650°C, cooled in air, and then annealed at 1040°C for 3 minutes, quenched in water, pickled, and then cold-rolled to a thickness of 0.35mm to prepare a cold-rolled sheet.
[249]
The cold-rolled sheet was adjusted to a dew point temperature of -40°C in an atmosphere of 30% hydrogen and 70% nitrogen for 60 seconds at 1050°C, and final annealing was performed to prepare an annealed steel sheet.
[250]
Then, as an insulating coating composition, triacetoxymethylsilane 25 parts by weight, triacetoxyvinylsilane 25 parts by weight, chromium hydroxide ((CH 3 CO 2 ) 7 Cr 3 (OH) 2 ) 15 parts by weight, cobalt hydroxide (Co (OH) 2 ) 15 parts by weight, strontium hydroxide (Sr(OH) 2 ) 3 parts by weight, boron nitride 15 parts by weight, and propylene glycol 2 parts by weight are mixed with distilled water to prepare a slurry form, and the slurry is thickened using a roll After coating with, it was heat-treated at 650°C for 30 seconds and cooled in air. The electrical steel sheet was subjected to stress relief annealing (SRA, Stress Relief Annealing) heat treatment at 820°C for 2 hours in a 100% nitrogen atmosphere, and then cooled in air. After the stress-relieving annealed steel sheet was treated at 60° C. and 95% humidity for 24 hours, the results of evaluating the degree of rust generation on the surface are shown in Table 3 below.
[251]
Comparative Example 1-5
[252]
After slowly adding about 7 parts by weight of MgO and CaO to the ionized water, about 20 parts by weight of CrO 3 causing an exothermic reaction was slowly injected into the solution (MgO, CaO + ionized water) and stirred until it became a transparent brown liquid, followed by branding. .
[253]
Thereafter, about 30 parts by weight of one type of acrylic resin or acrylic-styrene copolymer resin and 6.7 parts by weight of butyl carbitol as a reducing agent were injected into the solution to prepare an insulating coating composition.
[254]
It was carried out in the same manner as in Example 1-13, but an insulating film was formed using the prepared insulating film composition.
[255]
Comparative Example 1-6
[256]
Aluminum phosphate (Al(H 2 PO 4 ) 3 ) 50 parts by weight, Zinc phosphate (Zn(H 2 PO 4 ) 2 ) 50 parts by weight, epoxy resin 210 parts by weight, cobalt hydroxide An insulating coating composition containing 1 part by weight, 1 part by weight of strontium hydroxide, and 0.05 part by weight of a Ti chelating agent was used.
[257]
In the same manner as in Example 1-13, an insulating film was formed using the insulating film composition.
[258]
[Table 3]
[259]
As shown in Table 3, compared to Comparative Examples 1-5 and 1-6, it can be seen that the characteristics of Example 1-13 are significantly superior.
[260]
Experimental Example 2-1: Characteristics of each type of silane compound
[261]
Example 2-1
[262]
3.4% by weight of silicon (Si), aluminum (Al): 0.80% by weight, manganese (Mn): 0.17% by weight titanium (Ti): 0.0015% by weight, tin (Sn): 0.03% by weight, bismuth (Bi): 0.01 % By weight, carbon (C): 0.003% by weight, nitrogen (N): 0.0013% by weight, phosphorus (P): 0.012% by weight, sulfur (S): 0.001% by weight, the balance consisting of Fe and other inevitable impurities The slabs were prepared.
[263]
The slab was heated at 1130° C. and then hot-rolled to a thickness of 2.3 mm to prepare a hot-rolled sheet.
[264]
The hot-rolled sheet was wound at 650°C, cooled in air, and then annealed at 1040°C for 2 minutes, quenched in water, pickled, and then cold-rolled to a thickness of 0.35mm to prepare a cold-rolled sheet.
[265]
The cold-rolled sheet was subjected to final annealing by adjusting the dew point temperature in an atmosphere of 20% hydrogen and 80% nitrogen for 50 seconds at 1040°C, thereby producing an annealed steel sheet.
[266]
As an insulating coating composition, Triethyl (trifluoromethyl) silane (triethyl (trifluoromethyl) silane) 60 parts by weight, chromic anhydride (CrO 3 ) 20 parts by weight, magnesium oxide (MgO) 10 parts by weight and ethylene glycol 5 parts by weight with distilled water and The mixture was prepared in the form of a slurry, and the slurry was applied to the final annealed steel sheet using a roll, followed by heat treatment at 650°C for 25 seconds and cooling in air. The electrical steel sheet was subjected to stress relief annealing (SRA, Stress Relief Annealing) for 2 hours at 820°C in a 100% nitrogen atmosphere, and then cooled in air. The thickness of the insulating film was about 0.8 µm.
[267]
Examples 2-2 to 2-12
[268]
In the same manner as in Example 2-1, the contents and types of the silane compound, chromic acid compound, and ceramic powder in the insulating coating composition were replaced as shown in Table 4 below to form an insulating coating.
[269]
Comparative Example 2-1
[270]
In the same manner as in Example 2-1, but without a chromic acid compound, an insulating coating composition containing 100 parts by weight of Triethyl(trifluoromethyl)silane (triethyl(trifluoromethyl)silane) was used.
[271]
Comparative Example 2-2
[272]
In the same manner as in Example 2-1, but without a silane compound, an insulating coating composition containing 100 parts by weight of chromic anhydride was used.
[273]
Comparative Example 2-3
[274]
In the same manner as in Example 2-1, an insulating coating composition including 60 parts by weight of chromic anhydride and 40 parts by weight of magnesium oxide was used without a silane compound.
[275]
The properties of the electrical steel sheets prepared in Examples and Comparative Examples were measured and summarized in Table 5 below.
[276]
The iron loss (W 15 / 50 ) refers to the power loss that appears when sikyeoteul magnetized with the alternate current magnetic field frequency of 50Hz to 1.5Tesla.
[277]
In addition, the insulating properties were measured on the upper part of the insulating film using a Franklin measuring device according to ASTM A717 international standard.
[278]
In addition, the adhesion is expressed as the minimum arc diameter without film peeling when the specimen is bent 180° in contact with a 10 to 100 mm arc.
[279]
In addition, the surface feature is a result of visually evaluating the degree of uniformity of color and formation of a uniform film.
[280]
[Table 4]
[281]
[Table 5]
[282]
As shown in Tables 4 and 5, it can be seen that the insulating film properties of the examples are superior to those of the comparative examples. In addition, when the silane compound or the chromic acid compound is included alone, it can be confirmed that the film is extremely peeled and the magnetic properties are deteriorated.
[283]
6 is a scanning electron microscope (SEM) photograph of a cross section of an electrical steel sheet prepared in Example 2-2.
[284]
7 shows a scanning electron microscope (SEM) photograph of the surface of the electrical steel sheet prepared in Comparative Example 2-3. As shown in FIG. 6, in the case of Example 2-2, it can be seen that the beautiful insulating film is maintained even after the SRA. On the other hand, as shown in FIG. 7, in the case of Comparative Example 2-3, it can be seen that a number of cracks occur on the surface of the insulating film after SRA.
[285]
Experimental Example 2-2: Evaluation of polymer resin addition effect
[286]
Example 2-11
[287]
Silicon (Si) 4.5 wt%, Aluminum (Al): 0.80 wt%, Manganese (Mn): 0.15 wt% Titanium (Ti) 0.001 wt%, Tin (Sn) 0.05 wt%, Carbon (C) 0.004 Slabs were prepared containing 0.0015% by weight of nitrogen (N), 0.015% by weight of phosphorus (P), and 0.001% by weight of sulfur (S), the balance being Fe and other inevitable impurities.
[288]
The slab was heated at 1150° C. and then hot-rolled to a thickness of 2.3 mm to prepare a hot-rolled sheet.
[289]
The hot-rolled sheet was wound at 650°C, cooled in air, and then annealed at 1040°C for 3 minutes, quenched in water, pickled, and then cold-rolled to a thickness of 0.35mm to prepare a cold-rolled sheet.
[290]
The cold-rolled sheet was adjusted to a dew point temperature of -40°C in an atmosphere of 30% hydrogen and 70% nitrogen for 60 seconds at 1050°C, followed by final annealing to prepare an annealed steel sheet.
[291]
Then, a polymer resin was mixed with the insulating coating composition described in Example 2-2 as summarized in Table 6 below to prepare a slurry form, heat-treated at 650°C for 30 seconds, and cooled in air. The electrical steel sheet was subjected to a stress relief annealing (SRA, Stress Relief Annealing) heat treatment at 820° C. for 2 hours in a 100% nitrogen atmosphere and cooled in air. The insulating film was formed to a thickness of about 0.4 μm.
[292]
Table 6 shows the results of evaluating the degree of rust generation on the surface after the stress-relieving annealed steel sheet was treated at 60° C. and 95% humidity for 24 hours.
[293]
[Table 6]
[294]
As shown in Table 6, changes in iron loss, surface roughness, spot ratio, and rust area were confirmed according to changes in the type and amount of the polymer resin added.
[295]
The present invention is not limited to the embodiments, but may be manufactured in a variety of different forms, and those of ordinary skill in the art to which the present invention pertains may use other specific forms without changing the technical spirit or essential features of the present invention. It will be appreciated that it can be implemented. Therefore, it should be understood that the embodiments described above are illustrative and non-limiting in all respects.
[296]
[Explanation of code]
[297]
100: electrical steel sheet
[298]
10: electrical steel plate base
[299]
20: insulating film
Claims
[Claim 1]
An electrical steel sheet comprising an electrical steel sheet substrate and an insulating film located on one or both sides of the electrical steel sheet base, wherein the insulating film includes a silane compound and a metal hydroxide represented by the following Chemical Formula 1. [Formula 1] (In Formula 1, R 1 and R 2 are each independently hydrogen, a straight or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, L is a direct bond or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[Claim 2]
The electrical steel sheet according to claim 1, wherein the silane compound is represented by the following formula (2). [Formula 2] (In Formula 2, R 1 and R 2 are each independently hydrogen, a straight or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, L 1 is a direct bond or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[Claim 3]
The method of claim 1, wherein the silane compound is triacetoxy(methyl)silane, triacetoxy(vinyl)silane, and dimethyldimethacroyloxy-1-ethoxysilane. -di(methacroyloxy-1-ethoxy)silane) and 3-(trimethoxysilyl)propylmethacrylate (3-(trimethoxysilyl)propylmethacrylate).
[Claim 4]
The method of claim 1, wherein the metal hydroxide is Ni(OH) 2 , Co(OH) 2 , Cu(OH) 2 , Sr(OH) 2 , Ba(OH) 2 , Pd(OH) 2 , In(OH) 3 , (CH 3 CO 2 ) 7 Cr 3 (OH) 2 , Bi(OH) 3 and Sn(OH) 2 Electrical steel sheet containing at least one of.
[Claim 5]
The electrical steel sheet according to claim 1, wherein the insulating film further comprises a metal nitride, and contains 0.1 to 40% by weight of a metal nitride, 25 to 75% by weight of a silane compound, and 0.5 to 60% by weight of a metal hydroxide.
[Claim 6]
The method of claim 5, wherein the metal nitride BN, AlN, Si 3 N 4 , Mg 3 N 2 , Ca 3 N 2 , Sr 3 N 2 , Ba 3 N 2 , and Ge 3 N 4 including at least one of the species Electrical steel sheet.
[Claim 7]
The electrical steel sheet according to claim 1, wherein the electrical steel sheet satisfies the following General Formula 1. [General Formula 1] 20 ≤ TC ≤ 200 W/mK (In the above general formula 1, TC represents a thermal conductivity value measured by induction heating a 600 × 400 mm specimen at 230° C. and PPMS (Physical Property Measurement System).)
[Claim 8]
The method of claim 1, wherein the electrical steel substrate is C: 0.01% by weight or less, Si: 6.0% by weight or less, P: 0.5% by weight or less, S: 0.005% by weight or less, Mn: 0.1 to 1.0% by weight, Al: 0.40 To 2.0% by weight, N: 0.005% by weight or less, Ti: 0.005% by weight or less, and Sb, Sn, Ni or a combination thereof: 0.01 to 0.15% by weight, and the balance includes Fe and inevitable impurities.
[Claim 9]
An insulating coating composition for an electrical steel sheet comprising a silane compound represented by the following Chemical Formula 1 and a metal hydroxide. [Formula 1] (In Formula 1, R 1 and R 2 are each independently hydrogen, a straight or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, L is a direct bond or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[Claim 10]
The insulating coating composition for an electrical steel sheet according to claim 9, further comprising a metal nitride, and comprising 0.1 to 40% by weight of a metal nitride, 25 to 75% by weight of a silane compound, and 0.5 to 60% by weight of a metal hydroxide based on a solid content.
[Claim 11]
11. The method of claim 10, wherein the metal nitride BN, AlN, Si 3 N 4 , Mg 3 N 2 , Ca 3 N 2 , Sr 3 N 2 , Ba 3 N 2 , and Ge 3 N 4 including at least one of the species Insulating coating composition for electrical steel sheet.
[Claim 12]
Preparing a hot-rolled sheet by hot-rolling the slab, undergoing cold-rolling, and then preparing a steel sheet having final annealing; And forming an insulating film by applying an insulating film composition to the steel sheet, wherein the insulating film composition comprises a silane compound represented by the following Chemical Formula 1 and a metal hydroxide. [Formula 1] (In Formula 1, R 1 and R 2 are each independently hydrogen, a straight or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, L is a direct bond or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[Claim 13]
The method of claim 12, wherein the electrical steel sheet on which the insulating film is formed satisfies the following General Formula 1. [General Formula 1] 20 ≤ TC ≤ 200 W/mK (In the above general formula 1, TC represents a thermal conductivity value measured by induction heating a 600x400mm specimen at 230°C and PPMS (Physical Property Measurement System).)
[Claim 14]
A silane compound represented by the following formula (1); And at least one chromic acid compound among chromic anhydride, chromate, and dichromate. [Formula 1] (In Formula 1, R 1 is hydrogen, a halogen element, a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L is a direct bond. Or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[Claim 15]
The insulating coating composition for an electrical steel sheet according to claim 14, comprising 10 to 80 parts by weight of the silane compound and 20 to 90 parts by weight of the chromic acid compound based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound.
[Claim 16]
The insulating coating composition for an electrical steel sheet according to claim 14, wherein R 1 in Formula 1 is hydrogen, a halogen element, a linear or branched alkyl group or an alkoxy group.
[Claim 17]
[15] The insulating coating composition of claim 14, wherein in Formula 1, L is at least one of a direct bond, an alkylene group, and -CF 2 -.
[Claim 18]
The insulating coating composition of claim 14, wherein the silane compound is represented by the following formula (2). [Formula 2] (In Formula 2, R 1 to R 3 are each independently hydrogen, a halogen element, a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group, or an aminoalkyl group And L 1 is a direct bond or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[Claim 19]
The insulating coating composition for an electrical steel sheet according to claim 18, wherein R 2 and R 3 in Formula 2 are each independently hydrogen or a halogen element.
[Claim 20]
The method of claim 14, wherein the silane compound is Triethyl (trifluoromethyl) silane (triethyl (trifluoromethyl) silane), Trimethoxy (trifluoropropyl) silane (trimethoxy (trifluoropropyl) silane), and Dimethoxy-methyl (trifluoropropyl). ) silane (dimethoxy-methyl (trifluoropropyl) silane) and Perfluorooctyl-triethoxysilane (perfluorooctyl-triethoxysilane).
[Claim 21]
The insulating coating composition for an electrical steel sheet according to claim 14, further comprising 0.5 to 65 parts by weight of ceramic powder based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound.
[Claim 22]
The method of claim 21, wherein the ceramic powder is MgO, MnO, Al 2 O 3 , SiO 2 , TiO 2 , ZrO 2 , Al 6 Si 2 O 13 , Al 2 O 3 TiO 2 , Y 2 O 3 , 9Al 2 O 3 ·B 2 O 3 , BN, CrN, BaTiO 3 , SiC and TiC insulating coating composition containing at least one of.
[Claim 23]
The insulating coating composition for an electrical steel sheet according to claim 21, wherein the ceramic powder has an average particle diameter of 0.05 to 20 µm.
[Claim 24]
The method of claim 21, wherein based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound, acrylic resin, styrene resin, vinyl acetate resin, polyester resin, urethane resin, polyethylene resin, polypropylene resin, polyamide resin, poly An insulating coating composition for an electrical steel sheet further comprising 0.5 to 30 parts by weight of one or more polymer resins of carbonate resin, phenol resin, alkyd resin, and epoxy resin.
[Claim 25]
The method of claim 14, wherein based on 100 parts by weight of the total amount of the silane compound and the chromic acid compound, one of ethylene glycol, propylene glycol, glycerin, and butyl carbitol An insulating coating composition for an electrical steel sheet further comprising 1 to 15 parts by weight or more.
[Claim 26]
An electrical steel sheet substrate and an insulating film located on one or both sides of the electrical steel sheet substrate, wherein the insulating film is a silane compound represented by the following formula (1); And at least one chromic acid compound among chromic anhydride, chromate, and dichromate. [Formula 1] (In Formula 1, R 1 is hydrogen, a halogen element, a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L is a direct bond. Or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[Claim 27]
The electrical steel sheet according to claim 26, wherein the insulating film comprises 0.1 to 50% by weight of Si and 0.01 to 25% by weight of F.
[Claim 28]
The electrical steel sheet according to claim 26, wherein the insulating film has a thickness of 0.1 to 10 μm.
[Claim 29]
Manufacturing an electrical steel plate substrate; And forming an insulating film by applying an insulating film composition to one or both surfaces of the electrical steel substrate, wherein the insulating film composition includes a silane compound represented by the following formula (1); And at least one chromic acid compound among chromic anhydride, chromate, and dichromate. [Formula 1] (In Formula 1, R 1 is hydrogen, a halogen element, a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an aminoalkyl group, and L is a direct bond. Or a divalent linking group, m is an integer of 1 to 4, and n is 4-m.)
[Claim 30]
The method of claim 29, wherein the manufacturing of the electrical steel sheet substrate comprises: manufacturing a hot rolled sheet by hot rolling a slab; Cold-rolling the hot-rolled sheet to produce a cold-rolled sheet, and a step of final annealing the cold-rolled sheet.
[Claim 31]
The method of claim 29, wherein the forming of the insulating film comprises heat-treating the steel sheet coated with the insulating film composition at a temperature of 100 to 680°C.
[Claim 32]
The method of claim 29, further comprising the step of performing stress relief annealing at a temperature of 700 to 1000° C. after the step of forming the insulating film.