Title of the invention: Thermosetting resin composition, coating material for pre-coated metal, cured product and laminate
Technical field
[0001]
　The present invention relates to a laminate containing a thermosetting resin composition, a cured product composed of the composition, and a cured film composed of the composition.
[0002]
　The present invention also relates to a laminate containing a coating material for pre-coated metal, a cured product made of the coating material, and a cured film made of the coating material.
Background technology
[0003]
　Conventionally, thermosetting resin compositions containing polyols and alkyl etherified melamines have been used in various fields such as automobile paints and home appliance paints, and the storage stability of the compositions is good. In addition, it is required to have excellent durability and appearance of the obtained cured film. Further, curing of the thermosetting resin composition requires a heating time of 10 to 60 minutes at a temperature of approximately 110 to 160 ° C., but from the viewpoint of energy saving, heat that can be cured at a lower temperature and in a shorter time. There is a strong demand for curable resins.
[0004]
　In addition, as a steel sheet used for outdoor building materials such as roofs and wall materials and home appliances such as refrigerators, washing machines, and lighting fixtures, a coating is applied before molding and cutting, which is called pre-coated metal. Steel sheets are widely used. Pre-coated metal coating materials containing polyols and alkyl etherified melamine are used in various fields such as automobile paints and home appliance paints, and the coating materials have good storage stability and are obtained. It is required to have excellent durability and appearance of the cured film.
[0005]
　Generally, pre-coated metal is coated in a continuous line, and the drying time of about 10 to 120 seconds can be secured for its curing, but the peak metal temperature (PMT), which is the maximum temperature reached by the metal to be coated, is 150 to 260 ° C. Since it is necessary to reach the temperature, the drying furnace temperature may reach 300 ° C., and in recent years, there is a strong demand for a thermosetting resin that can be cured in a shorter time, particularly from the viewpoint of energy saving.
[0006]
　Here, in the cross-linking reaction between the polyol and the alkyl etherified melamine , ether exchange proceeds between the hydroxyl group (A- OH ) of the polyol and the ether group (B- OR ) of the alkyl etherified melamine, and the alkyl etherified melamine The derived alcohol (R-OH) is desorbed. Although this reaction is an equilibrium reaction, cross-linking can proceed irreversibly by volatilizing the desorbed alcohol to the outside of the system, and the conditions for this are a temperature of approximately 110 to 160 ° C and heating for 10 to 60 minutes. It takes time. A catalyst may be used for the purpose of promoting cross-linking in this cross-linking reaction, and it has been reported that a Lewis acid catalyst is effective in addition to protonic acid.
[0007]
　For example, in Patent Document 1, various Lewis acids can be applied when a polyol having an epoxy equivalent, hydroxyl value, glass transition temperature and weight average molecular weight in a specific range is cured with an amino resin or an isocyanate containing a block. It is disclosed that a particularly preferable catalyst is a zinc catalyst such as zinc chloride, zinc naphthenate, and zinc octylate.
[0008]
　Patent Document 2 describes polyester resin and melamine by using a solvent selected from a specific Lewis acid catalyst, a perfluoroacetic acid catalyst, and the like under baking conditions of 280 to 450 ° F (138 to 232 ° C.) for 5 to 60 seconds. When the cross-linking reaction of the cross-linking agent and the epoxy resin is promoted, and when a low boiling point solvent such as an aromatic compound, an ester or a ketone solvent or a mixture of an aromatic ester or a ketone solvent is required as a solvent, rapid solvent evaporation is required. It is stated to be advantageous. However, as a result of the verification by the present inventors, good results were not obtained when the tests were conducted with reference to these examples.
[0009]
　As the alkyl etherified melamine, industrially, methyl etherified melamine (hereinafter referred to as "methylated melamine") and butyl etherified melamine (hereinafter referred to as "butylated melamine") are produced and used. However, in Patent Document 3, baking with ethyl etherified melamine (hereinafter referred to as "ethylated melamine") resin at 90 to 180 ° C. for 20 to 30 minutes (more specifically, 120 ° C. for 30 minutes). It is disclosed that by curing the polyol under the conditions without a catalyst, a cured film having a better balance between hardness and water resistance can be formed as compared with the case where methylated melamine and butylated melamine are used.
[0010]
　Further, Patent Document 4 describes that in the reaction of an acrylic polyol having a hydroxyl value of 80 to 110 mgKOH / g and a weight average molecular weight of 10,000 to 100,000 and an alkyl etherified melamine, a phosphoric acid alkyl ester is used as a catalyst and 80 to 120 ° C. (more specific). It is disclosed that a cured film having certain physical properties can be formed by heating at 80 ° C. for 30 minutes. Unlike Patent Document 3, Patent Document 4 does not show that ethylated melamine is preferable to methylated melamine and butylated melamine, and even in Examples, a coating formed of ethylated melamine or butylated melamine. There is no difference in the physical properties of the membrane. In addition, Patent Document 4 shows that the performance is not sufficiently exhibited when an acrylic polyol having a hydroxyl value of 60 mgKOH / g is used.
[0011]
　Patent Document 5 discloses a coating film for an outer panel containing a specific alkoxysilane, at least one partially hydrolyzable condensate of an organosilicon compound, and a film-forming resin.
[0012]
　Patent Document 6 describes a specific vinyl (thio) ether group or a compound having a carboxyl group blocked by a heterocyclic group having a vinyl-type double bond having an oxygen atom or a sulfur atom as a hetero atom (poly polyol). Includes), compounds with reactive functional groups that can form chemical bonds with the blocked carboxyl groups by heating (including melamine resins), and compounds containing epoxy groups, specific sulfur-containing compounds and specific Lewis. A thermosetting composition containing a thermolatent acid catalyst containing an acid, or a reaction in which the blocked carboxyl group in one molecule and the blocked carboxyl group can form a chemical bond by heating. A thermosetting composition containing a self-crosslinking compound having a sex functional group is disclosed.
Prior art literature
Patent documents
[0013]
Patent Document 1: Japanese Patent Application Laid-Open No. 8-176465
Patent Document 2: Japanese
Patent Application Laid-Open No. 2004-518788 Patent Document 3: Japanese Patent Application Laid-Open No. 2014-098105
Patent Document 4: Japanese Patent Application Laid-Open No. 2017-071666
Patent Document 5: Japanese Patent Application Laid- Open No. 10-130581
Patent Document 6: JP-A-2005-036236
Outline of the invention
Problems to be solved by the invention
[0014]
　The present invention provides a thermosetting resin composition that can obtain a cured film having excellent durability and appearance at a low temperature and having excellent storage stability, and a method for producing a cured film composed of the composition. The purpose is.
[0015]
　Further, according to the present invention, a cured film having excellent durability and appearance can be obtained in a short heating time, and a coating material for pre-coated metal having excellent storage stability, and a method for producing a cured film made of the coating material. The purpose is to provide.
Means to solve problems
[0016]
　As a result of studying catalysts and solvents for thermosetting resin compositions containing polyols and alkyl etherified melamines and coating materials for precoated metals, the present inventors have compared them with the widely used protonic acid catalysts. A pair anion produced by deprotonating a cation consisting of a Lewis acid having a metal center, particularly a metal element having an electronegative degree of Pauling of 1.31 to 2.02, and a protonic acid having an acid dissociation constant of 1.0 or less. It was found that the use of a Lewis acid catalyst consisting of the above has a high effect of promoting the reaction at a low temperature and a high effect of promoting the reaction in a short time.
[0017]
　The reason why such a high effect can be obtained is that when the Lewis acid catalyst interacts with oxygen and nitrogen atoms contained in polyol and alkyl etherified melamine, Lewis having a metal element whose electronegativity is too low is the central component. When an acid is used, the interaction is strong, but the polarization is too large and the solubility in polyols, alkyl etherified melamines, and solvents tends to be poor. Conversely, if the electronegativity of the central metal is too high, the interaction is weak. It is considered that this is because the activation effect tends to be inferior. Further, the reason why the pair anions having a pKa of 1.0 or less are good is that they are stable as anions and the electron density of the Lewis acid center can be kept lower, so that the Lewis acid center metal and the hetero atom are used. It is presumed that this is due to the increased interaction between the two, which effectively functions as a catalyst.
[0018]
　Therefore, as a result of further investigating the influence of the solubility of the Lewis acid catalyst on the solvent, the present inventors further investigated the solvent having a solubility of the Lewis acid catalyst of 0.01% by mass or more in a certain amount or more with respect to the entire solvent. It has been found that when it is not contained in an amount, the above-mentioned reaction promoting effect is limited.
[0019]
　The present inventors have completed the present invention based on these findings. That is, the present invention includes the following aspects.
[0020]
　[1] (A) Resin having a hydroxyl group having a hydroxyl value of 25 to 300 mgKOH / g (excluding alkyl etherified melamine resin (B)), (B) alkyl etherified melamine resin, ( C) A Lewis acid catalyst composed of a cation composed of a metal having an electronegative degree of Pauling of 1.31 to 2.02 and a counter anion which is a deprotonated product of a protonic acid having an acid dissociation constant pKa of 1.0 or less. And (D), the solvent (D) contains
　a solvent (D-1) having a Hildebrand solubility parameter value (SP value) of 18.6 to 47.9, and the total amount of the solvent (D). The content of the solvent (D-1) with respect to the solvent (D-1) is 21% by mass or more, and
　the solubility of the Lewis acid catalyst (C) in the solvent (D-1) is 0.01% by mass or more. A
thermosetting resin composition , wherein the content of —S) is 4% by mass or more based on the total amount of the solvent (D) .
[0021]
　[2] The thermosetting resin composition according to Item [1], wherein the Lewis acid catalyst (C) is at least one selected from the group consisting of nitrates, sulfates and halides.
[0022]
　[3] The item [1] or [2], wherein the cation constituting the Lewis acid catalyst (C) is composed of at least one metal selected from the group consisting of magnesium, aluminum and nickel. Thermosetting resin composition.
[0023]
　[4] The thermosetting property according to any one of Items [1] to [3], wherein the solvent (D-1) is at least one selected from the group consisting of alcohol and water. Resin composition.
[0024]
　[5] The resin (A) having a hydroxyl group is at least one resin selected from the group consisting of an acrylic resin having a hydroxyl group, a polyester resin having a hydroxyl group, an epoxy resin having a hydroxyl group, and a urethane resin having a hydroxyl group. The thermosetting resin composition according to any one of the items [1] to [4].
[0025]
　[6] The item characterized in that the resin (A) having a hydroxyl group is at least one resin selected from the group consisting of an acrylic resin having a hydroxyl group, a polyester resin having a hydroxyl group, and a urethane resin having a hydroxyl group [6]. 1] The thermosetting resin composition according to any one of [4].
[0026]
　[7] (E) From the group consisting of pigments, dyes, leveling agents, stability improvers, foaming inhibitors, weather resistance improvers, armpit inhibitors, antioxidants, dispersants, wetting agents, tincture agents and UV absorbers. The thermosetting resin composition according to any one of Items [1] to [6], further comprising at least one selected additive.
[0027]
　[8] The mass ratio (A / B) of the solid content of the resin (A) having a hydroxyl group to the solid content of the alkyl etherified melamine resin (B) is 95/5 to 45/55. The thermosetting resin composition according to any one of the items [1] to [7].
[0028]
　[9] The content of the Lewis acid catalyst (C) is 0.01 to 5% by mass with respect to 100 parts by mass of the total solid content of the resin (A) having a hydroxyl group and the alkyl etherified melamine resin (B). The thermosetting resin composition according to any one of items [1] to [8], which is characterized by a range of parts.
[0029]
　[10] A cured product comprising the thermosetting resin composition according to any one of items [1] to [9].
[0030]
　[11] Production of a cured product, which comprises a step of heating the thermosetting resin composition according to any one of items [1] to [9] to a temperature of 60 to 125 ° C. to cure it. Method.
[0031]
　[12] The method for producing a cured product according to Item [11], wherein the heating time in the step is in the range of 10 seconds to 60 minutes.
[0032]
　[13] A laminate comprising a cured film made of the thermosetting resin composition according to any one of Items [1] to [9].
[0033]
　[14] A method for producing a laminate containing a coating film and a cured film, wherein the thermosetting resin composition according to any one of items [1] to [9] is applied to the coating film to form a coating film. A method for producing a laminate, which comprises a step of forming the coating film and a step of heating the coating film at a temperature of 60 to 125 ° C. to form a cured film.
[0034]
　[15] The method for producing a laminate according to Item [14], wherein the coating is made of metal or resin.
[0035]
　[16] (A) Resin having a hydroxyl group having a hydroxyl value of 25 to 300 mgKOH / g (excluding alkyl etherified melamine resin (B)), (B) alkyl etherified melamine resin, ( C) A Lewis acid catalyst composed of a cation composed of a metal having an electronegative degree of Pauling of 1.31 to 2.02 and a counter anion which is a deprotonated product of a protonic acid having an acid dissociation constant pKa of 1.0 or less. From (D) solvents and (E) pigments, dyes, leveling agents, stability improvers, foaming inhibitors, weather resistance improvers, armpit inhibitors, antioxidants, dispersants, wetting agents, tincture agents and UV absorbers. The
　solvent (D) contains a solvent (D-1) having a Hildebrand solubility parameter value (SP value) of 18.6 to 47.9, and contains at least one additive selected from the above group . The content of the solvent (D-1) is 21% by mass or more with respect to the total amount of the solvent (D
　), and the solubility of the Lewis acid catalyst (C) in the solvent (D-1) is 0.01 % by mass. The content of the solvent (DS) which is% or more is 4% by mass or more with respect to the total amount of the solvent (D), and
　the content of the additive (E) is the resin (A) and the resin. A coating material for pre-coated metal, which is 10 parts by mass or more and 300 parts by mass or less with respect to a total of 100 parts by mass of (B).
[0036]
　[17] The coating material for precoat metal according to Item [16], wherein the Lewis acid catalyst (C) is at least one selected from the group consisting of nitrates, sulfates and halides.
[0037]
　[18] The item [16] or [17], wherein the cation constituting the Lewis acid catalyst (C) is composed of at least one metal selected from the group consisting of magnesium, aluminum and nickel. Coat material for pre-coated metal.
[0038]
　[19] The precoated metal according to any one of Items [16] to [18], wherein the solvent (D-1) is at least one selected from the group consisting of alcohol and water. Coat material.
[0039]
　[20] The resin (A) having a hydroxyl group is at least one resin selected from the group consisting of an acrylic resin having a hydroxyl group, a polyester resin having a hydroxyl group, an epoxy resin having a hydroxyl group, and a urethane resin having a hydroxyl group. The coating material for pre-coated metal according to any one of items [16] to [19].
[0040]
　[21] The item characterized in that the resin (A) having a hydroxyl group is at least one resin selected from the group consisting of an acrylic resin having a hydroxyl group, a polyester resin having a hydroxyl group, and a urethane resin having a hydroxyl group [21]. The coating material for pre-coated metal according to any one of 16] to [19].
[0041]
　[22] The mass ratio (A / B) of the solid content of the resin (A) having a hydroxyl group to the solid content of the alkyl etherified melamine resin (B) is 95/5 to 45/55. The coating material for precoat metal according to any one of the items [16] to [21].
[0042]
　[23] The content of the Lewis acid catalyst (C) is 0.01 to 5% by mass with respect to 100 parts by mass of the total solid content of the resin (A) having a hydroxyl group and the alkyl etherified melamine resin (B). The coating material for precoat metal according to any one of items [15] to [22], which is characterized by having a range of parts.
[0043]
　[24] A cured product made of the coating material for pre-coated metal according to any one of items [16] to [23].
[0044]
　[25] The step of heating and curing the coating material for pre-coated metal according to any one of items [16] to [23] under the conditions of a peak metal temperature of 120 ° C. or higher and 250 ° C. or lower and 5 seconds or less is included. A method for producing a cured product.
[0045]
　[26] A laminate comprising a cured film made of the coating material for precoat metal according to any one of items [16] to [23].
[0046]
　[27] A method for producing a laminate containing a coating film and a cured film, wherein the coating material for precoat metal according to any one of items [16] to [23] is applied to the coating film to form a coating film. A method for producing a laminate, which comprises a step of forming and a step of heating the coating film under conditions of a peak metal temperature of 120 ° C. or higher and 250 ° C. or lower and 5 seconds or less to form a cured film.
[0047]
　[28] The method for producing a laminate according to item [27], wherein the covering body is a metal or a resin.
Effect of the invention
[0048]
　According to the present invention, a cured film having excellent durability and appearance can be obtained at a low temperature, storage stability is better than that of a conventional low-temperature curable isocyanate-based resin composition, and the hardness is high. Provided are a thermosetting resin composition capable of forming a coating film, and a method for producing a cured product composed of the composition. In addition, the realization of low-temperature curing has made it possible not only to save energy in conventional systems, but also to newly coat plastics with low heat resistance.
[0049]
　Further, according to the present invention, a cured film having excellent durability and appearance can be obtained in a short heating time, and storage stability is better than that of a conventional thermosetting isocyanate-based resin composition. Provided are a coating material for pre-coated metal capable of forming a coating film having high hardness, and a method for producing a cured product made of the coating material.
Mode for carrying out the invention
[0050]
　Hereinafter, the present invention will be described in detail.
[0051]
　[Thermosetting Resin Composition]
　The thermosetting resin composition of the present invention (hereinafter, also simply referred to as "the composition of the present invention") has (A) a solid content having a hydroxyl value of 25 to 300 mgKOH / g. , Resin having a hydroxyl group (excluding alkyl etherified melamine resin (B)), (B) alkyl etherified melamine resin, and (C) Pauling made of a metal having an electronegative degree of 1.31 to 2.02. It contains a Lewis acid catalyst composed of a cation and a counter anion which is a deprotonated product of a protonic acid having an acid dissociation constant pKa of 1.0 or less, and a solvent (D), and an additive (E) is further added if necessary. It may be included.
[0052]
　In the composition of the present invention, the solvent (D) contains a solvent (D-1) having a Hildebrand solubility parameter value (SP value) of 18.6 to 47.9, and is based on the total amount of the solvent (D). The content of the solvent (D-1) is 21% by mass or more, and
　the solubility of the Lewis acid catalyst (C) in the solvent (D-1) is 0.01% by mass or more (D-). The content of S) is 4% by mass or more with respect to the total amount of the solvent (D).
[0053]
　 As the resin (A)
　having a hydroxyl group used in the present invention (hereinafter, also simply referred to as "resin (A)"), the hydroxyl value of the solid content is 25 to 300 mgKOH / g. The resin is not particularly limited as long as it is a resin other than the alkyl etherified melamine resin (B) described later, but for example, an acrylic resin having a hydroxyl group, a polyester resin having a hydroxyl group, an epoxy resin having a hydroxyl group, and a urethane having a hydroxyl group. Examples include resin. Among these, an acrylic resin having a hydroxyl group, a polyester resin having a hydroxyl group, and a urethane resin having a hydroxyl group are preferable, and an acrylic resin having a hydroxyl group and a polyester resin having a hydroxyl group are more preferable. The resin (A) may be used alone or in combination of two or more.
[0054]
　The hydroxyl value of the resin (A) is preferably 30 to 250 mgKOH / g, more preferably 40 to 200 mgKOH / g (solid content). When the hydroxyl value is within the above range, the crosslink density of the coating film is high, the strength and hardness of the coating film are sufficient, the flexibility of the coating film is appropriate, and the impact resistance and appearance are good.
[0055]
　The polystyrene-equivalent weight average molecular weight (Mw) of the resin (A) measured by GPC is usually 5,000 to 200,000, preferably 10,000 to 100,000, and more preferably 20,000. It is ~ 80,000. When the Mw of the resin (A) is within the above range, it is excellent in coatability, appearance of the coating film, strength, hardness, abrasion resistance and the like.
[0056]
　Examples of commercially available products of the resin (A) include "Cotax LH-601" and "Cotax LH-591" manufactured by Toray Fine Chemicals Co., Ltd., "Almatex 646" manufactured by Mitsui Chemicals Co., Ltd., and "ALMA". Examples include "Tex 646SB", "Olestar Q810", and "Olestar Q519".
[0057]
　The content ratio of the resin (A) (solid content) to the total amount of the composition of the present invention is preferably 1 to 60% by mass, more preferably 1.1 to 57.0% by mass, and further preferably 5.0 to 40. It is 0.0% by mass. When the content ratio of the resin (A) is within the above range, it is excellent in coatability, storage stability, coating film strength, hardness, abrasion resistance and the like.
[0058]
　
　The alkyl etherified melamine resin (B) used in the present invention (hereinafter, also simply referred to as "melamine resin (B)") is a melamine resin (the melamine resin is a melamine resin). It refers to a thermosetting resin obtained from formaldehyde.) A resin in which at least a part of the methylol group is alkyl etherified.
[0059]
　A preferable example of the melamine resin (B) is the ethylated (ethyl etherified) melamine resin described in Patent Document 3.
[0060]
　As commercially available products of the melamine resin (B), "Uban 20SE60" and "Uban 28-60" manufactured by Mitsui Chemicals, Inc., "Symel 327" and "Symel 370" series manufactured by Daicel Ornex are used. be able to.
[0061]
　The polystyrene-equivalent weight average molecular weight of the melamine resin (B) measured by GPC (gel permeation chromatography) is preferably 800 to 15000, more preferably 1000 to 7000, and further preferably 1100 to 5000. is there. When the weight average molecular weight of the melamine resin (B) is within the above range, a resin composition having an appropriate viscosity can be obtained, and a cured product having excellent mechanical properties, smoothness, appearance and the like can be obtained.
[0062]
　The melamine resin (B) can preferably be obtained by condensing melamine, formaldehyde and an alcohol having an alkyl chain having 1 to 6 carbon atoms in the presence of an acid catalyst. As a method for producing such a melamine resin (B), the method described in Patent Document 3 can be used. For example, in the case of an ethylened melamine resin, ethanol is used as the alcohol, and as the ethanol, hydrous ethanol may be used, or so-called mixed ethanol containing a small amount of methanol, isopropanol or the like may be used. ..
[0063]
　The melamine is not particularly limited, and may be synthesized by a conventionally known method or a commercially available product.
[0064]
　The formaldehyde may be an aqueous solution or a solid paraformaldehyde. From the viewpoint of economy, paraformaldehyde having a formalin concentration of 80% or more is preferable.
[0065]
　The content ratio of the melamine resin (B) (solid content) to the total amount of the composition of the present invention is preferably 0.1 to 40% by mass, more preferably 0.12 to 33.0% by mass, still more preferably 3 to 3 to It is 25% by mass. When the content ratio of the melamine resin (B) is within the above range, a coating film having an excellent balance between hardness and flexibility can be obtained.
[0066]
　The mass ratio (A / B) of the solid content of the resin (A) to the solid content of the melamine resin (B) is preferably 95/5 to 45/55, more preferably 85/15 to 65/35. Is. When the mass ratio (A / B) is in the above range, a coating film having an excellent balance between hardness and flexibility can be obtained.
[0067]
　
　The Lewis acid catalyst (C) used in the present invention has a proton made of a metal having an electronegative degree of Pauling of 1.31 to 2.02 and an acid dissociation constant pKa of 1.0 or less. It consists of a counter anion, which is a deprotonated form of the protonic acid of.
[0068]
　Examples of metals having an electronegativity of Pauling of 1.31 to 2.02 include magnesium, manganese, aluminum, cobalt, nickel, tin, zinc, copper and bismuth. Of these, magnesium, aluminum and nickel are preferred in terms of fast curing rate. Further, when the resin (A) is an aqueous dispersion system, the Lewis acid catalyst (C) composed of an inorganic salt may act as a coagulant, but nickel, copper and cobalt do not easily coagulate the resin (A). Is preferable.
[0069]
　Examples of the protonic acid (breasted acid) having an acid dissociation constant pKa of 1.0 or less include nitric acid, sulfuric acid, hydrochloric acid, and hydrobromic acid. The acid dissociation constant is a value when water is used as a solvent.
[0070]
　The Lewis acid catalyst (C) is preferably at least one selected from the group consisting of nitrates, sulfates and halides, more preferably nitrates or halides, and even more preferably nitrates.
[0071]
　Specific examples of the Lewis acid catalyst (C) include magnesium nitrate, manganese nitrate, aluminum nitrate, zinc nitrate, cobalt nitrate, copper nitrate, nickel nitrate, nickel sulfate, bismuth chloride and the like.
[0072]
　The content of the Lewis acid catalyst (C) is preferably 0.01 to 5% by mass with respect to 100 parts by mass of the total solid content of the resin (A) having a hydroxyl group and the alkyl etherified melamine resin (B). Parts, more preferably 0.1 to 4 parts by mass. When the content of the Lewis acid catalyst (C) is within the above range, a thermosetting resin composition having excellent storage stability and low temperature curability can be obtained.
[0073]
　
　The solvent (D) used in the present invention includes a solvent (D-1) having a Hildebrand solubility parameter value (SP value) of 18.6 to 47.9. The content of the solvent (D-1) with respect to the total amount of the solvent (D) is 21% by mass or more, preferably 30 to 99% by mass.
[0074]
　Further, among the solvents (D-1), the content of the solvent (DS) in which the solubility of the Lewis acid catalyst (C) is 0.01% by mass or more is based on the total amount of the solvent (D). 4% by mass or more, preferably 10 to 95% by mass.
[0075]
　Examples of the solvent (D-1) include alcohol, water, tetrahydrofuran and the like. Of these, alcohol and water are preferred. The solvent (D-1) may be used alone or in combination of two or more. Examples of the alcohol include methanol, ethanol, iso-propanol, iso-butanol, n-butanol, sec-butanol and the like.
[0076]
　The solvent (DS) differs depending on the type of the Lewis acid catalyst (C). For example, as shown in Table 1-1 and Table 1-2 (hereinafter, these are collectively referred to as "Table 1", and the other tables are also referred to in the same manner), the Lewis acid catalyst (C) is nickel sulfate. (II) In the case of hexahydrate, water corresponds to the solvent (DS), but methanol, ethanol, iso-propanol, iso-butanol, n-butanol, sec-butanol and tetrahydrofuran correspond to the solvent (DS). ) Does not apply. When the Lewis acid catalyst (C) is magnesium nitrate hexahydrate, water, methanol, ethanol, iso-propanol, iso-butanol, n-butanol, sec-butanol and tetrahydrofuran are all solvents (D-). Corresponds to S).
[0077]
　The solvent (D) may contain a solvent (D-2) other than the solvent (D-1). The solvent (D-2) is not particularly limited, and for example, an alkylbenzene solvent such as benzene, toluene, and xylene, an acetate solvent such as ethyl acetate, propyl acetate, butyl acetate, amyl acetate, and methyl acetoacetate. Examples thereof include ketone solvents such as dioxane, acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone.
[0078]
　The total content of the solvent (D) with respect to the total amount of the composition of the present invention is preferably 30 to 95% by mass, more preferably 40.0 to 90.0% by mass, and further preferably 50.0 to 80.0% by mass. %.
[0079]
　
　The composition of the present invention may contain an additive (E), if necessary. The additive (E) is not particularly limited as long as the effect of the present invention is not impaired, and known additives (for example, the additives described in Patent Documents 1 to 4) can be used. Specific examples thereof include pigments, dyes, leveling agents, stability improvers, foaming inhibitors, weather resistance improvers, armpit inhibitors, antioxidants, dispersants, wetting agents, tincture agents and ultraviolet absorbers. The additive (E) may be used alone or in combination of two or more.
[0080]
　The content of the additive (E) with respect to the total amount of the composition of the present invention is preferably 0 to 30% by mass.
[0081]
　The total amount of the resin (A), the melamine resin (B), the Lewis acid catalyst (C) and the additive (E) is preferably 10 to 60% by mass with respect to the total amount of the composition of the present invention. More preferably, it is 20 to 50% by mass. When the total content of the components (A), (B), (C) and (E) is within the above range, a thermosetting resin composition having excellent coatability, coating film physical properties and storage stability can be obtained. Be done.
[0082]
　
　The first aspect of the cured product of the present invention (hereinafter, also referred to as "first cured product") is characterized by comprising the composition of the present invention, and is usually in the form of a cured film. Is. In addition, the first aspect of the laminated body of the present invention (hereinafter, also referred to as "first laminated body") is characterized by containing a cured film made of the composition of the present invention.
[0083]
　In the method for producing the first cured product (cured film) of the present invention, the composition of the present invention is heated to a temperature of 60 to 125 ° C., preferably 60 to 120 ° C., more preferably 60 to 90 ° C. and cured. It includes a step (hereinafter, also referred to as “heating step (1)”). As described above, the method of the present invention is excellent in productivity because the composition of the present invention can be cured at a low temperature, that is, the time from the start of heating to the time when the curing temperature is reached can be shortened.
[0084]
　The heating time in the heating step (1) is preferably 10 seconds to 60 minutes, more preferably 30 seconds to 60 minutes, still more preferably 1 to 60 minutes, still more preferably 1 to 40 minutes, and particularly preferably 5 to. It's 30 minutes. As described above, since the composition of the present invention can be cured in a short heating time, the method of the present invention is excellent in productivity. The heating may be performed in two or more steps. Further, the heating step (1) may be performed under reduced pressure, under an inert gas atmosphere or the like.
[0085]
　The composition of the present invention can be suitably used for paint (coating material) applications. That is, after the composition of the present invention is applied to a coating film to form a coating film, the coating film is heated (dried) under the same conditions as in the heating step (1) to form a cured film. The first laminate of the present invention can be produced.
[0086]
　Examples of the coating body (base material) include iron, aluminum, zinc, stainless steel, metal materials such as those surface-treated, vinyl chloride, polyethylene terephthalate, polyethylene, polypropylene, polycarbonate, ABS, and surfaces thereof. Examples thereof include resin materials such as those that have been treated. Further, those coated with a primer, an intermediate coating, and a top coating coating can also be used, if necessary.
[0087]
　As described above, since the present invention can be cured at a low temperature and in a short time, thermal deformation of the covering body can be suppressed. That is, in the present invention, since a covering body having inferior heat resistance can be used, various covering bodies can be selected according to a desired application.
[0088]
　The method for applying the composition of the present invention to the coating material is not particularly limited, and a spray coating method, a dip coating method, a roll coating method, a gravure coating method, a spin coating method, and a bar coater or a doctor blade are used. The method etc. can be mentioned.
[0089]
　The thickness of the cured film is not particularly limited and may be appropriately selected depending on the desired application, but is preferably 5 to 50 μm, more preferably 10 to 20 μm.
[0090]
　[Coating Material for Pre-Coated Metal]
　The coating material for pre-coated metal of the present invention (hereinafter, also simply referred to as "coating material of the present invention") contains (A) a hydroxyl group having a solid content having a hydroxyl value of 25 to 300 mgKOH / g. Resin (excluding alkyl etherified melamine resin (B)), (B) alkyl etherified melamine resin, (C) cation consisting of a metal having an electronegative degree of 1.31 to 2.02, and A Lewis acid catalyst composed of a counter anion which is a deprotonated product of a protonic acid having an acid dissociation constant pKa of 1.0 or less, (D) a solvent, and (E) a pigment, a dye, a leveling agent, a stability improver, and foam suppression. It contains at least one additive selected from the group consisting of agents, weather resistance improvers, armpit inhibitors, antioxidants, dispersants, wetting agents, tincture agents and UV absorbers.
[0091]
　In the coating material of the present invention, the solvent (D) contains a solvent (D-1) having a Hildebrand solubility parameter value (SP value) of 18.6 to 47.9, and is based on the total amount of the solvent (D). The content of the solvent (D-1) is 21% by mass or more, and
　the solubility of the Lewis acid catalyst (C) in the solvent (D-1) is 0.01% by mass or more (D-). The content of S) is 4% by mass or more with respect to the total amount of the solvent (D), and
　the content of the additive (E) is 100 parts by mass in total of the resin (A) and the resin (B). On the other hand, it is 10 parts by mass or more and 300 parts by mass or less.
[0092]
　The details of the components (A) to (E) constituting the coating material of the present invention are the resin (A), the melamine resin (B), and the Lewis acid catalyst in the above-mentioned composition of the present invention, except as described below. (C), solvent (D) and additive (E) are as described.
[0093]
　The content ratio of the resin (A) (solid content) to the total amount of the coating material of the present invention is preferably 1 to 60% by mass, more preferably 1.11 to 51.8% by mass, and further preferably 5.0 to 40. It is 0.0% by mass. When the content ratio of the resin (A) is within the above range, it is excellent in coatability, storage stability, coating film strength, hardness, abrasion resistance and the like.
[0094]
　The content ratio of the melamine resin (B) (solid content) to the total amount of the coating material of the present invention is preferably 0.1 to 40% by mass, more preferably 0.12 to 30.0% by mass, and further preferably 3. It is 0 to 25.0% by mass. When the content ratio of the melamine resin (B) is within the above range, a coating film having an excellent balance between hardness and flexibility can be obtained.
[0095]
　The mass ratio (A / B) of the solid content of the resin (A) to the solid content of the melamine resin (B) is preferably 95/5 to 45/55, more preferably 85/15 to 65/35. Is. When the mass ratio (A / B) is in the above range, a coating film having an excellent balance between hardness and flexibility can be obtained.
[0096]
　The content of the Lewis acid catalyst (C) is preferably 0.01 to 5% by mass with respect to 100 parts by mass of the total solid content of the resin (A) having a hydroxyl group and the alkyl etherified melamine resin (B). Parts, more preferably 0.1 to 4 parts by mass. When the content of the Lewis acid catalyst (C) is within the above range, a coating material for pre-coated metal having excellent storage stability and short-time curability can be obtained.
[0097]
　The total content of the solvent (D) with respect to the total amount of the coating material of the present invention is preferably 30 to 95% by mass, more preferably 40.0 to 90.0% by mass, and further preferably 50.0 to 80.0% by mass. %.
[0098]
　The content of the additive (E) in the coating material of the present invention is 10 parts by mass or more and 300 parts by mass or less, preferably 50 parts by mass with respect to 100 parts by mass in total of the resin (A) and the resin (B). It is 250 parts by mass or less.
[0099]
　The total amount of the resin (A), the melamine resin (B), the Lewis acid catalyst (C) and the additive (E) is preferably 10 to 60% by mass with respect to the total amount of the coating material of the present invention. More preferably, it is 20 to 50% by mass. When the total content of the components (A), (B) and (E) is within the above range, a coating material for precoat metal having excellent coatability, coating film physical properties and storage stability can be obtained.
[0100]
　
　The second aspect of the cured product of the present invention (hereinafter, also referred to as "second cured product") is characterized by being composed of the coating material of the present invention, and is usually in the form of a cured film. Is. In addition, the second aspect of the laminated body of the present invention (hereinafter, also referred to as "second laminated body") is characterized by containing a cured film made of the coating material of the present invention.
[0101]
　In the method for producing the second cured product (cured film) of the present invention, the coating material of the present invention is subjected to conditions of a peak metal temperature of 120 ° C. or higher and 250 ° C. or lower and 5 seconds or less, preferably a peak metal temperature of 130 ° C. or higher and 180 ° C. or higher. It includes a step of heating and curing under the conditions of 0.5 seconds to 5 seconds (hereinafter, also referred to as “heating step (2)”). The peak metal temperature refers to the temperature at which the surface temperature of the metal to which the coating material is applied reaches. As described above, the coating material of the present invention can be cured in a short heating time, so that the method of the present invention is excellent in productivity. The heating may be performed in two or more steps. Further, the heating step (2) may be performed under reduced pressure, under an inert gas atmosphere or the like.
[0102]
　The coating material of the present invention can be suitably used for paint (coating material) applications. That is, after the coating material of the present invention is applied to the coating film to form a coating film, the coating film is heated (dried) under the same conditions as in the heating step (2) to form a cured film. The second laminate of the present invention can be produced.
[0103]
　Examples of the covering body (base material) include iron, aluminum, zinc, stainless steel, and metal materials such as those surface-treated. Further, those coated with a primer, an intermediate coating, and a top coating coating can also be used, if necessary.
[0104]
　As described above, since the present invention can be cured in a short time, thermal deformation of the covering body can be suppressed.
[0105]
　The method of applying the coating material of the present invention to the covering body is not particularly limited, and a spray coating method, a dip coating method, a roll coating method, a gravure coating method, a spin coating method, and a bar coater or a doctor blade are used.
　The thickness of the cured film, which includes methods and the like, is not particularly limited and may be appropriately selected depending on the desired application, but is preferably 5 to 50 μm, and more preferably 10 to 20 μm.
Example
[0106]
　Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples.
[0107]
　[Material] In the following
　Examples and Comparative Examples, the composition (coating material) and the raw materials used when preparing the coating material and the coating material (base material) used when applying the composition are as follows. ..
[0108]
　
　<< Polyester resin having hydroxyl group >>
・ (A-1) "Almatex P646" manufactured by Mitsui Chemicals Co., Ltd.
　Solvent: Solvento # 100 (manufactured by Exxon Mobile Chemical Co., Ltd., SP value = 18. 0) / Methyl isobutyl ketone (SP value = 17.2) = 　9/1 mixed solvent
　Solid content: 60%
　Weight average Molecular weight: 51,000
Hydroxyl value: 52 mgKOH / g
· (A-2) Mitsui Chemicals Co., Ltd. ) "Almatex P646SB"
　Solvent: sec-butanol (SP value = 22.1)
　Solid content: 60%
　Weight average Molecular weight: 51,000
　Hydroxyl value: 52 mgKOH / g
　<< Acrylic resin with hydroxyl group >>
・ (A- 3) "Cotax LH-591" manufactured by Toray Fine Chemicals Co., Ltd.
　Solvent: n-butyl acetate (SP value = 17.4)
　Solid content: 55%
　Hydroxyl value: 31 mgKOH / g
・ (A-4) Mitsui Chemicals "Orestar Q810" manufactured by Co., Ltd.
　Solvent: n-butyl acetate (SP value = 17.4)
　Solid content: 52%
　Weight average molecular weight: 35,000
　Hydroxyl value:
50 mgKOH / g · (A-5) "Orestar Q519" manufactured by Mitsui Chemicals Co., Ltd.
　Solvent: n-butyl acetate (SP value = 17.4) and methyl isobutyl ketone (SP value = 17.2) Mixed solvent
　Solid content: 50%
　hydroxyl value: 151 mgKOH / g
· (A-6) "Olestar Q203" manufactured by Mitsui Chemicals Co., Ltd.
　Solvent: Solvento # 100 (manufactured by Exxon Mobile Chemical Co., Ltd., SP value = 18.0) Mixed solvent of methyl isobutyl ketone (SP value = 17.2)
　Solid content: 60%
　hydroxyl value: 97 mgKOH / g
　<< Titanium oxide-dispersed polyol solution A1 >>
　Paint conditioner (RED DEVIL, 1400-0H) with additives (1400-0H) 100 parts by mass of titanium oxide (manufactured by Ishihara Sangyo, CR-93) as E), 116.7 parts by mass of polyester resin (A-1) having a hydroxyl group, Solvento # 100 (manufactured by Exxon Mobile Chemical Co., Ltd., SP value = 18) as a solvent 0.0) 25 parts by mass was added, 130 parts by mass of glass beads (manufactured by Sekiya Rika Co., Ltd., 2 mm diameter) were added, and the mixture was stirred for 5 hours. After stirring, the glass beads were filtered through a mesh to obtain a titanium oxide-dispersed polyol solution A1.
[0109]
　<< Titanium oxide-dispersed polyol liquid A1'>> A
　paint conditioner (manufactured by RED DEVIL, 1400-0H), titanium oxide (manufactured by Ishihara Sangyo, CR-93) as an additive (E), and a polyester resin (A-1) having a hydroxyl group. ) And Solvento # 100 (manufactured by Exxon Mobile Chemical Co., Ltd., SP value = 18.0) as a solvent, and the amounts shown in Tables 10 to 13 (values ​​in the table are parts by mass) are added, and glass beads (manufactured by Exxon Mobile Chemical Co., Ltd. 200 parts by mass (2 mm diameter) manufactured by Sekiya Rika Co., Ltd. was added and stirred for 5 hours. After stirring, the glass beads were filtered through a mesh to obtain a titanium oxide-dispersed polyol solution A1'.
[0110]
　<< Titanium oxide dispersed polyol liquid A2 >> A
　paint conditioner (manufactured by RED DEVIL, 1400-0H), titanium oxide (manufactured by Ishihara Sangyo, CR-93) as an additive (E), and a polyester resin (A-2) having a hydroxyl group. , And Solbesso # 100 (manufactured by Exxon Mobile Chemical Co., Ltd., SP value = 18.0) as a solvent, and the amounts shown in Table 11 (the values ​​in the table are parts by mass) are added, and glass beads (Sekiya Rika Co., Ltd.) are added. 200 parts by mass (2 mm diameter) manufactured by the company was added and stirred for 5 hours. After stirring, the glass beads were filtered through a mesh to obtain a titanium oxide-dispersed polyol solution A2.
[0111]
　<< Titanium oxide dispersed polyol liquid A4 >> A
　paint conditioner (manufactured by RED DEVIL, 1400-0H), titanium oxide (manufactured by Ishihara Sangyo, CR-93) as an additive (E), and a polyester resin (A-4) having a hydroxyl group. , And Solbesso # 100 (manufactured by Exxon Mobile Chemical Co., Ltd., SP value = 18.0) as a solvent, and the amounts shown in Table 11 (the values ​​in the table are parts by mass) are added, and glass beads (Sekiya Rika Co., Ltd.) are added. 200 parts by mass (2 mm diameter) manufactured by the company was added and stirred for 5 hours. After stirring, the glass beads were filtered through a mesh to obtain a titanium oxide-dispersed polyol solution A4.
[0112]
　<< Titanium oxide-dispersed polyol liquid A6 >> A
　paint conditioner (manufactured by RED DEVIL, 1400-0H), titanium oxide (manufactured by Ishihara Sangyo, CR-93) as an additive (E), and a polyester resin (A-6) having a hydroxyl group. , And Solvento # 100 (manufactured by Exxon Mobile Chemical Co., Ltd., SP value = 18.0) as a solvent, and the amounts shown in Table 11 (the values ​​in the table are parts by mass) are added, and glass beads (Sekiya Rika Co., Ltd.) are added. 200 parts by mass (2 mm diameter) manufactured by the company was added and stirred for 5 hours. After stirring, the glass beads were filtered through a mesh to obtain a titanium oxide-dispersed polyol solution A6.
[0113]
　
· (a-1) "Cotax LH-601" manufactured by Toray Fine Chemicals Co., Ltd.
　Solvent: toluene (SP value = 18.2) and n-acetate Mixed solvent
　solid content of butyl (SP value = 17.4) : 50%
　hydroxyl value: 20 mgKOH / g
　
　<< (B-1) ethylened melamine resin solution >> Stirrer
　, thermometer , 126 g (1.0 mol) of melamine, 196 g (6.0 mol) of paraformaldehyde with 92% formalin concentration and 276 g (6.0 mol) of ethanol in a four-necked flask equipped with a reflux condenser and a nitrogen introduction tube. , The temperature was raised to the reflux temperature. After the methylolation reaction was carried out at the reflux temperature for 1 hour, 0.180 g (0.53 mmol) of a 50% aqueous solution of paratoluenesulfonic acid (water; SP value = 47.9) was added, and ethyl etherification was carried out in the reflux state. The reaction was carried out for 3 hours. Then, the reaction product was neutralized with 0.160 g (0.80 mmol) of a 20% sodium hydroxide solution, and then ethanol and water were distilled off under reduced pressure, and then with isobutanol (SP value = 23.5). An ethylened melamine resin solution (B-1) was obtained by diluting until the non-volatile content became 70% by weight. The weight average molecular weight of the obtained resin was 2,000.
[0114]
　<< Butylated melamine resin >>
- (B-2) "Uban 20SE60" manufactured by Mitsui Chemicals Co., Ltd.
　Solvent: Xylene (SP value = 18.0) / n-butanol (SP value = 23.3) = 40/60 Mixed solvent
　Solid content: 60%
　Weight average molecular weight: 4,000
· (B-3) "Uban 28-60" manufactured by Mitsui Chemicals Co., Ltd.
　Solvent: n-butanol (SP value = 23.3)
　Solid content: 60%
　Weight average molecular weight: 2,300
　<< methylated melamine resin >>
・ (B-4) “Simel 327” manufactured by Daicel Ornex Co., Ltd.
　Solvent: iso-butanol (SP value = 23.5)
　Solid content: 90%
・ (B-) 5) "Simel 370" manufactured by Daicel Ornex
　Solvent: iso-butanol (SP value = 23.5)
　Solid content: 88%
　
　(C-1) to (C) shown in Table 1. -7).
[0115]
　
　(c'-1) to (c'-7) shown in Table 1. The details of the catalysts (c'-4), (c'-5) and (c'-7) are as follows.
・ (C'-4) Nikka Octix Zinc manufactured by Nippon Kagaku Sangyo Co., Ltd .
　: Zinc octylate (zinc content: 18%)
・ (c'-5) Nitto Kasei Co., Ltd. “Neostan U-801”
　component: Di-n-butyltin dilaurate
・ (c'-6) p-toluenesulfonic acid monohydrate
・ (c'-7) KING INDUSTRIES “NACURE 4000”
　component: alkyl phosphate
　
・ acetate n-Butyl (SP value = 17.4)
, Methylisobutylketone (SP value = 17.2)
, Solvento 100 (SP value = 18.0)
, Toluene (SP value = 18.2)
, Xylene (SP value = 18.0)
・ Water (SP value = 47.9)
・ Methanol (SP value = 29.7)
・ Ethanol (SP value = 26)
・ iso-butanol (SP value = 23.5)
・ iso-propanol (SP ) Value = 23.5)
・ N-Butanol (SP value = 23.3)
・ sec-Butanol (SP value = 22.1)
・ tetrahydrofuran (SP value = 18.8)
　
・ Steel plate (Test Piece Co., Ltd.) Made by JIS-G3141 (SPCC, SB), 5Φ 1 piece PB-N144, 150mm x 70mm x 0.8mm thickness) -Polycarbonate
resin plate ("PC 1600" made by Takiron Co., Ltd., 150mm x 70mm x 2 thickness 0.0 mm, hereinafter also referred to as "PC base material")
-Acrylic resin plate ( "Acrylite L-001" manufactured by Mitsubishi Chemical Co., Ltd., 150 mm x 70 mm x thickness 2.0 mm), hereinafter also referred to as "PMMA base material" Refer to. )
・ ABS resin plate (manufactured by Testpiece Co., Ltd., JIS, K, 6873 (ABS) black, 150 mm × 70 mm × thickness 2.0 mm, hereinafter also referred to as “ABS base material”)
・ PET film (Toray Co., Ltd. ) Made of "Lumirror U34", 300 mm x 150 mm x thickness 100 μm, hereinafter also referred to as "PET base material")
・ Zinc iron plate (JIS-G-3302) 150 mm x 300 mm x thickness 0.3 mm
　[Evaluation items and evaluation method ]
　
　"POLYMER HANDBOOK FOURTH EDITION" by J. Brandrup et al., Published by A WILEY-INTERSCIENCE, P.676-697 was referred to.
[0116]
　
　Measure the catalyst (C) or (c') in a glass sample bottle, add the solvent (D) so that the concentration of the catalyst is 0.01% by mass or 1% by mass, and cover the lid. Then, the mixture was immersed in an ultrasonic cleaner (“US-3KS” manufactured by SNT Co., Ltd.) filled with water at 25 ° C. for 2 minutes and ultrasonically applied. A liquid having a completely uniform appearance was judged as "◯", and a liquid having undissolved residue was judged as "x". The evaluation results are shown in Table 1.
[0117]
　 The
　compositions obtained in Examples and Comparative Examples were placed in a transparent glass sample bottle, covered, and allowed to stand at 25 ° C. for 30 minutes. Visually observe the appearance, "◎" when there is no precipitate or undissolved substance, "○" when there is uniform cloudiness but no separation or sedimentation, and when there is precipitate or undissolved substance Was determined to be "x".
[0118]
　
　After allowing the composition in a glass sample bottle to stand at 25 ° C. for 8 hours, tilt the sample bottle to visually observe the appearance and flow. Those with properties (composition or coating material flowing) were rated as "○", and those without fluidity (solidified) were rated as "x".
[0119]
　
　Visually observe the coating film of the test plate with coating film obtained in Examples and Comparative Examples, and when there is no foreign matter and the surface is smooth, "◎" indicates that foreign matter or unevenness is partially present. The case where it was seen was evaluated as "○", and the case where foreign matter or unevenness was seen on the entire surface or the case where the gloss was impaired was evaluated as "x".
[0120]
　 The
　surface of the coating film of the test plate with coating film obtained in Examples and Comparative Examples was rubbed with xylene in gauze under a load of 300 g, and the surface of the material to be coated was rubbed. The first digit of the number of round trips until appears is rounded off, 200 or more round trips are "◎", 100 to 190 times are "○", 30 to 90 times are "△", 0 to 20 times are "x". It was judged.
[0121]
　 According to
　JIS K 5600-5-4, apply the pencil lead at an angle of about 45 ° to the test coat surface, and press it strongly against the test coat surface so that the lead does not break, and at a uniform speed forward. I moved it about 10 mm. The hardness symbol of the hardest pencil that did not cause scratches on the coating film was defined as the pencil hardness.
[0122]
[Table 1-1]

[0123]
[Table 1-2]

　[Examples A1 to 29, Comparative Examples A1 to 20]
　Resin (A) or (a) having a hydroxyl group, melamine resin (B), Lewis acid catalyst (C) or other catalyst (c' ) And the solvent (D) were mixed at the ratios shown in Tables 2 to 4 to prepare and evaluate a composition (coating material).
[0124]
　The obtained composition was applied to a steel sheet (150 mm × 70 mm × thickness 0.8 mm) using a bar coater so that the cured film thickness was 15 μm, and then the composition was heated at 80 ° C. for 30 minutes to cure. A test plate with a coating film was prepared and evaluated.
[0125]
　The evaluation results are shown in Tables 2-4.
[0126]
[Table 2]

[0127]
[Table 3]

[0128]
[Table 4-1]

[0129]
[Table 4-2]

　[Examples A30 to 45 and Comparative Examples A21 to 39]
　Titanium oxide dispersed polyol solution A1, melamine resin (B), Lewis acid catalyst (C) or other catalyst (c') and solvent (D). ) Was mixed at the ratios shown in Tables 5 to 7 to prepare and evaluate a composition (white coating material).
[0130]
　The obtained composition was applied to a steel sheet (150 mm × 70 mm × thickness 0.8 mm) using a bar coater so that the cured film thickness was 15 μm, and then the composition was heated at 80 ° C. for 30 minutes to cure. A test plate with a coating film was prepared and evaluated.
[0131]
　The evaluation results are shown in Tables 5-7.
[0132]
[Table 5]

[0133]
[Table 6-1]

[0134]
[Table 6-2]

[0135]
[Table 7]

　[Examples A46 to 48 and Comparative Examples A40 to 43]
　Resin having a hydroxyl group (A), melamine resin (B), Lewis acid catalyst (C) or other catalyst (c'), polyisocyanate (Asahi Kasei) A composition (coating material) was prepared and evaluated by mixing "Duranate TKA-100") manufactured by Co., Ltd. and the solvent (D) at the ratios shown in Table 8.
[0136]
　The obtained composition is coated on the above-mentioned PC base material, PMMA base material and ABS base material using a bar coater so that the cured film thickness becomes 15 μm, and then the composition is heated at 80 ° C. for 30 minutes. A test plate with a coating film was prepared and evaluated by curing.
[0137]
　The evaluation results are shown in Table 8.
[0138]
[Table 8]

[Examples A49 to 51]
　A composition obtained by mixing a resin (A) having a hydroxyl group, a melamine resin (B), a Lewis acid catalyst (C) and a solvent (D) at the ratios shown in Table 9. (Coating material) was prepared and evaluated.
[0139]
　The obtained composition is coated on the above-mentioned PET substrate using a bar coater so that the cured film thickness is 10 μm, and then the composition is heated at 120 ° C. for 30 seconds to be cured. A test plate with a film was prepared and evaluated.
[0140]
　The evaluation results are shown in Table 9.
[0141]
[Table 9]

　[Examples B1 to 30, Comparative Examples B1 to 20]
　Resins (A) or (a) having hydroxyl groups, melamine resins (B), Lewis acid catalysts (C) or other catalysts (c'), A coating material was prepared by mixing the catalyst (D) and the additive (E) in the ratios shown in Tables 10 to 13.
[0142]
　After attaching Thermolabel (R) -5E125 and 170 (manufactured by Nichiyu Giken Kogyo Co., Ltd.) to a galvanized iron plate (150 mm x 300 mm x thickness 0.3 mm), the coating material is cured and dried on the opposite surface of the label. After painting with a bar coater to a thickness of 15 μm, it was immediately placed in an automatic discharge dryer ATO-102 (manufactured by Nippon Test Panel Industry Co., Ltd.) and heated at a predetermined temperature and time. Since the thermolabel discolors when it reaches each temperature in units of 10 ° C., the maximum temperature at which discoloration is observed is defined as PMT.
[0143]
　The holding time of the PMT was set from the time when the plate to be coated was taken out of the oven and discoloration was observed every second by the above measurement method, and the elapsed time from that time was described. In addition, in the examination at n = 2, if there was a label that was discolored and a label that was not discolored, it was considered that the label was discolored at that time.
[0144]
　In the case of Example B1, when the two coated plates were placed in an oven at 160 ° C and discharged after 34 seconds, the label at 120 ° C was discolored but the label at 130 ° C was not discolored. When the two separately painted plates were discharged at 160 ° C. after 35 seconds, one of the labels at 130 ° C. was discolored, so that it was considered that the temperature reached 130 ° C. within 34 to 35 seconds. When the two separately painted plates were discharged at 160 ° C. after 39 seconds, the label at 140 ° C. was discolored, but the label at 150 ° C. was not discolored.
[0145]
　From the above results, the time that the PMT was held at 140 ° C. and the coated plate at 130 ° C. or higher reached 130 ° C. within 34 to 35 seconds, and was held at least at 130 ° C. or higher for 4 seconds of 35 to 39 seconds. Therefore, it was written as 4 to 5 seconds.
[0146]
　The test plate with a coating film obtained as described above was evaluated. The evaluation results are shown in Tables 10 to 13.
[0147]
[Table 10]

[0148]
[Table 11-1]

[0149]
[Table 11-2]

[0150]
[Table 12]

[0151]
[Table 13]

The scope of the claims
[Claim 1]
(A) Resin having a hydroxyl group having a solid content having a hydroxyl value of 25 to 300 mgKOH / g (excluding alkyl etherified melamine resin (B)),
(B) alkyl etherified melamine resin,
(C) Pauling A Lewis acid catalyst composed of a cation composed of a metal having an electronegative degree of 1.31 to 2.02 and a counter anion which is a deprotonated product of a protonic acid having an acid dissociation constant pKa of 1.0 or less, and
(D. ) Solvent
, the
　solvent (D) contains a solvent (D-1) having a Hildebrand solubility parameter value (SP value) of 18.6 to 47.9, and the solvent with respect to the total amount of the solvent (D). The
　solvent (DS) in which the content of (D-1) is 21% by mass or more and the solubility of the Lewis acid catalyst (C) in the solvent (D-1) is 0.01% by mass or more. The thermocurable
resin composition is characterized in that the content of is 4% by mass or more based on the total amount of the solvent (D) .
[Claim 2]
　The thermosetting resin composition according to claim 1, wherein the Lewis acid catalyst (C) is at least one selected from the group consisting of nitrates, sulfates and halides.
[Claim 3]
　The thermosetting resin composition according to claim 1 or 2, wherein the cation constituting the Lewis acid catalyst (C) is composed of at least one metal selected from the group consisting of magnesium, aluminum and nickel. ..
[Claim 4]
　The thermosetting resin composition according to any one of claims 1 to 3, wherein the solvent (D-1) is at least one selected from the group consisting of alcohol and water.
[Claim 5]
　The resin (A) having a hydroxyl group is at least one resin selected from the group consisting of an acrylic resin having a hydroxyl group, a polyester resin having a hydroxyl group, an epoxy resin having a hydroxyl group, and a urethane resin having a hydroxyl group. The thermosetting resin composition according to any one of claims 1 to 4.
[Claim 6]
　Claims 1 to 4 are characterized in that the resin (A) having a hydroxyl group is at least one resin selected from the group consisting of an acrylic resin having a hydroxyl group, a polyester resin having a hydroxyl group, and a urethane resin having a hydroxyl group. The thermosetting resin composition according to any one of the above.
[Claim 7]
(E) At least selected from the group consisting of pigments, dyes, leveling agents, stability improvers, foaming inhibitors, weather resistance improvers, armpit inhibitors, antioxidants, dispersants, wetting agents, tincture agents and UV absorbers. The thermosetting resin composition according to any one of claims 1 to 6, further comprising one kind of additive.
[Claim 8]
　The claim is characterized in that the mass ratio (A / B) of the solid content of the resin (A) having a hydroxyl group to the solid content of the alkyl etherified melamine resin (B) is 95/5 to 45/55. The thermosetting resin composition according to any one of 1 to 7.
[Claim 9]
　The content of the Lewis acid catalyst (C) is in the range of 0.01 to 5 parts by mass with respect to a total of 100 parts by mass of the solid content of the resin (A) having a hydroxyl group and the alkyl etherified melamine resin (B). The thermosetting resin composition according to any one of claims 1 to 8, wherein the thermosetting resin composition is characterized by the above.
[Claim 10]
　A cured product comprising the thermosetting resin composition according to any one of claims 1 to 9.
[Claim 11]
　A method for producing a cured product, which comprises a step of heating the thermosetting resin composition according to any one of claims 1 to 9 to a temperature of 60 to 125 ° C. to cure the thermosetting resin composition.
[Claim 12]
　The method for producing a cured product according to claim 11, wherein the heating time in the step is in the range of 10 seconds to 60 minutes.
[Claim 13]
　A laminate comprising a cured film made of the thermosetting resin composition according to any one of claims 1 to 9.
[Claim 14]
　A method for producing a laminate containing a coating film and a cured film, wherein the
　thermosetting resin composition according to any one of claims 1 to 9 is applied to the coating film to form a coating film.
　A
method for producing a laminate , which comprises a step of heating the coating film at a temperature of 60 to 125 ° C. to form a cured film .
[Claim 15]
　The method for producing a laminated body according to claim 14, wherein the covering body is a metal or a resin.
[Claim 16]
(A) Resin having a hydroxyl group having a solid content having a hydroxyl value of 25 to 300 mgKOH / g (excluding alkyl etherified melamine resin (B)),
(B) alkyl etherified melamine resin,
(C) Pauling A Lewis acid catalyst composed of a cation composed of a metal having an electronegative degree of 1.31 to 2.02 and a counter anion which is a deprotonated product of a protonic acid having an acid dissociation constant pKa of 1.0 or less,
(D). From the
group consisting of solvents and (E) pigments, dyes, leveling agents, stability improvers, foaming inhibitors, weather resistance improvers, armpit inhibitors, antioxidants, dispersants, wetting agents, tincture agents and UV absorbers. The 　solvent (D)
contains at least one additive to be selected, and the
solvent (D) contains a solvent (D-1) having a Hildebrand solubility parameter value (SP value) of 18.6 to 47.9, and the solvent (D-1). The content of the solvent (D-1) with respect to the total amount of D) is 21% by mass or more, and
　the solubility of the Lewis acid catalyst (C) in the solvent (D-1) is 0.01% by mass or more. The content of a certain solvent (DS) is 4% by mass or more with respect to the total amount of the solvent (D), and
　the content of the additive (E) is the resin (A) and the resin (B). A
coating material for precoat metal, which is 10 parts by mass or more and 300 parts by mass or less with respect to a total of 100 parts by mass .
[Claim 17]
　The coating material for precoat metal according to claim 16, wherein the Lewis acid catalyst (C) is at least one selected from the group consisting of nitrates, sulfates and halides.
[Claim 18]
　The coating material for a precoat metal according to claim 16 or 17, wherein the cation constituting the Lewis acid catalyst (C) is composed of at least one metal selected from the group consisting of magnesium, aluminum and nickel.
[Claim 19]
　The coating material for precoat metal according to any one of claims 16 to 18, wherein the solvent (D-1) is at least one selected from the group consisting of alcohol and water.
[Claim 20]
　The resin (A) having a hydroxyl group is at least one resin selected from the group consisting of an acrylic resin having a hydroxyl group, a polyester resin having a hydroxyl group, an epoxy resin having a hydroxyl group, and a urethane resin having a hydroxyl group. The coating material for pre-coated metal according to any one of claims 16 to 19.
[Claim 21]
　Claims 16 to 19 are characterized in that the resin (A) having a hydroxyl group is at least one resin selected from the group consisting of an acrylic resin having a hydroxyl group, a polyester resin having a hydroxyl group, and a urethane resin having a hydroxyl group. The coating material for pre-coated metal according to any one of the above.
[Claim 22]
　The claim is characterized in that the mass ratio (A / B) of the solid content of the resin (A) having a hydroxyl group to the solid content of the alkyl etherified melamine resin (B) is 95/5 to 45/55. The coating material for pre-coated metal according to any one of 16 to 21.
[Claim 23]
　The content of the Lewis acid catalyst (C) is in the range of 0.01 to 5 parts by mass with respect to a total of 100 parts by mass of the solid content of the resin (A) having a hydroxyl group and the alkyl etherified melamine resin (B). The coating material for precoat metal according to any one of claims 16 to 22, wherein the coating material is for precoat metal.
[Claim 24]
　A cured product comprising the coating material for pre-coated metal according to any one of claims 16 to 23.
[Claim 25]
　Curing according to any one of claims 16 to 23, comprising a step of heating and curing the coating material for precoat metal under the conditions of a peak metal temperature of 120 ° C. or higher and 250 ° C. or lower and 5 seconds or less. Manufacturing method of things.
[Claim 26]
　A laminate comprising a cured film made of the coating material for precoat metal according to any one of claims 16 to 23.
[Claim 27]
　A method for producing a laminate including a coating film and a cured film, wherein the
　coating material for precoat metal according to any one of claims 16 to 23 is applied to the coating film to form a coating film, and the
　above-mentioned step. A
method for producing a laminate , which comprises a step of heating a coating film under conditions of a peak metal temperature of 120 ° C. or higher and 250 ° C. or lower and 5 seconds or less to form a cured film .
[Claim 28]
　The method for producing a laminated body according to claim 27, wherein the covering body is a metal or a resin.