JP2015108049A - Coating composition capable of forming crepe pattern coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition capable of providing a coating steel plate forming a crepe pattern coating film on a metal plate and excellent in processability, weather resistance and chemical resistance.SOLUTION: There is provided a coating composition capable of forming a crepe pattern coating film containing a hydroxyl group-containing resin (A), a melamine resin (B), a blocked polyisocyanate compound (C), a sulfonic acid compound (D) and an amine compound (E) with the component (A) of 50 to 90 pts.mass, the content (B) of 8 to 25 pts.mass, the component (C) of 2 to 25 pts.mass, the component (D) of 0.1 to 3.0 pts.mass based on 100 pts.mass of the total solid content of the hydroxyl group-containing resin (A), the melamine resin (B) and the blocked polyisocyanate compound (C) and having a molar ratio of the amine compound (E)/the sulfonic acid compound (D) of 1.5 to 30.

Description

  The present invention relates to a coating composition capable of forming a itch pattern coating film excellent in processability, weather resistance and chemical resistance on a metal plate, a glazing pattern coating film forming method using the coating composition, and a coated metal plate .

In recent years, various coating compositions and coating methods have been studied from the viewpoint of consumer luxury, and there are precoated steel sheets that have low gloss by blending extender pigments such as silica, calcium carbonate, and talc into the coating composition. However, there are problems such as poor processability and weather resistance of the coating film.
Accordingly, in order to obtain a low-gloss pre-coated steel sheet, a coated steel sheet having a crease-pattern coating film formed on a metal plate has been put into practical use. Painted steel sheet with a crease-pattern coating film is superior in workability and weather resistance compared to low-gloss pre-coated steel sheets containing silica and other extender pigments, so it is often used for the roofs and walls of factories and houses. It has become.

  For example, Patent Document 1 discloses an invention of a coating composition comprising an acid catalyst blocked with an acrylic resin, a polyester resin, an alkyl etherified melamine resin, a blocked isocyanate and an amine. However, the coating film described in Patent Document 1 has a “good appearance without baking and the like being generated on the coating film after baking (8th to 9th lines in the upper left column on page 2 in the specification)”. , It does not generate a stagnation coating film.

  Patent Document 2 discloses a modified polyester resin (A), a polyester resin or an acrylic resin (B) containing a hydroxyl group, a low-nucleated methylated melamine resin (C), and a sulfone as a coating composition that generates a crease pattern coating film. An invention of a coating composition containing a mixture (D) of 1 equivalent of an acid and a secondary or tertiary amine having a boiling point of 30 to 250 ° C. is disclosed.

In Patent Document 3, an acid catalyst (c) is used as a coating composition that generates a crease pattern coating film with respect to 100 parts by weight of the total resin solid content of the hydroxyl group-containing organic resin (a) and the amino resin (b). A glazing paint (A) containing 1 to 50 parts by weight of a secondary amine and / or a tertiary amine compound (d) having a boiling point of 0.1 to 5 parts by weight and a boiling point of 30 to 300 ° C. is disclosed.
However, although the paint film described in Patent Document 2 or Patent Document 3 can be obtained as a paint film on a metal plate, any of processability, weather resistance, and chemical resistance is insufficient.

Japanese Patent Laid-Open No. 4-130168 JP 2002-146280 A JP 2006-51652 A

  An object of the present invention is to find a coating composition which can provide a coated steel sheet having a whipped pattern coating film formed on a metal plate and excellent in workability, weather resistance and chemical resistance.

As a result of intensive studies, the present inventors have found that a coating composition containing a certain amount of a hydroxyl group-containing resin (A), a melamine resin (B), a blocked polyisocyanate compound (C), a sulfonic acid compound (D), and an amine compound (E). As a result, it has been found that a coated steel sheet can be provided on which a glazing pattern coating film is formed on a metal plate and which is excellent in workability, weather resistance and chemical resistance, and the present invention has been completed.
That is, the present invention
“1. A coating composition containing a hydroxyl group-containing resin (A), a melamine resin (B), a blocked polyisocyanate compound (C), a sulfonic acid compound (D) and an amine compound (E), A), 50 to 90 parts by mass of component (A) and 8 to 25 parts by mass of component (B) based on 100 parts by mass of the total solid content of melamine resin (B) and blocked polyisocyanate compound (C) 2 to 25 parts by mass of component (C), 0.1 to 3.0 parts by mass of component (D), and the amine compound (E) / sulfonic acid compound (D) molar ratio is 1.5 to 30. A coating composition capable of forming a glazing pattern coating film,
2. The coating composition according to 1, wherein the hydroxyl group-containing resin (A) is a hydroxyl group-containing polyester resin,
3. The coating composition according to Item 1 or 2, wherein the melamine resin (B) is a fully alkyl methylated melamine resin,
4). The coating composition according to any one of 1 to 3, wherein the blocked polyisocyanate compound (C) is a blocked product of an aliphatic polyisocyanate compound,
5. The coating composition according to any one of 1 to 4, wherein the blocking agent in the blocked polyisocyanate compound (C) is at least one selected from pyrazoles, oximes, phenols and lactams,
6). The coating composition as described in any one of 1-5 whose boiling point of an amine compound (E) is 30-250 degreeC.
7). Hydroxyl-containing polyester resin, fully alkyl-type methylated melamine resin, aliphatic polyisocyanate nurate methylethyl ketoxime blocked product, dodecylbenzenesulfonic acid and triethylamine-containing coating composition, hydroxyl-containing polyester resin, fully alkyl-type methyl 50 to 90 parts by mass of a hydroxyl group-containing polyester resin and 8 to 25 parts by mass, 2-25 parts by mass of a methyl ethyl ketoxime blocked product of an aliphatic polyisocyanate nurate, 0.1-3.0 parts by mass of dodecylbenzenesulfonic acid, and triethylamine / dodecyl Wrinkle pattern coating film formable coating composition, wherein the molar ratio of Nzensuruhon acid is 1.5 to 30,
8). The coating composition according to any one of 1 to 7 on the primer coating film of the article to be coated on which a primer coating film is formed on a metal plate whose surface may be subjected to chemical conversion treatment. A paint pattern forming method characterized by painting and baking
The present invention relates to a coated metal plate obtained by the method for forming a coating film according to 9.8.

  The coating composition of the present invention can provide a coated steel sheet having a uniform crease pattern coating film formed on a metal plate and having excellent workability, weather resistance, and chemical resistance.

  The present invention relates to a paint capable of forming a glazing pattern coating film containing a certain amount of a hydroxyl group-containing resin (A), a melamine resin (B), a blocked polyisocyanate compound (C), a sulfonic acid compound (D) and an amine compound (E). Relates to the composition. Hereinafter, “a paint composition capable of forming a paint pattern” may be abbreviated as “a paint pattern paint”.

Hydroxyl-containing resin (A) The hydroxyl-containing resin (A) is a resin having two or more hydroxyl groups in one molecule, and may have a carboxyl group as necessary. Specific examples of the hydroxyl group-containing resin (A) include a polyester resin, an acrylic resin, an epoxy resin, a polyurethane resin, and the like, and a hydroxyl group-containing polyester resin is preferable from the viewpoint of the workability and weather resistance of the coating film. Examples of the hydroxyl group-containing polyester resin include oil-free polyester resin, alkyd resin, urethane-modified polyester resin, and silicone-modified polyester resin. The oil-free polyester resin can be usually produced by an esterification reaction or a transesterification reaction with the polybasic acid component (a1) and the alcohol component (a2).

  The said polybasic acid component (a1) can use the compound normally used as a polybasic acid component at the time of manufacture of a polyester resin. As a polybasic acid component (a1), an alicyclic polybasic acid, an aliphatic polybasic acid, an aromatic polybasic acid etc. can be used, for example.

  An alicyclic polybasic acid is a compound having one or more alicyclic structures (mainly 4 to 6 membered rings) and two or more carboxyl groups in one molecule, an acid anhydride of the compound, and an ester of the compound It is a monster. Examples of the alicyclic polybasic acid include 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, and 3-methyl. -1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, alicyclic polyvalent carboxylic acid such as 1,3,5-cyclohexanetricarboxylic acid; Examples thereof include anhydrides of these alicyclic polyvalent carboxylic acids; lower alkyl esterified products of these alicyclic polyvalent carboxylic acids. An alicyclic polybasic acid can be used individually or in combination of 2 or more types.

As the alicyclic polybasic acid, in particular, 1,2-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic anhydride, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-cyclohexene-1 , 2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic anhydride can be preferably used.
An aliphatic polybasic acid is an aliphatic compound having two or more carboxyl groups in one molecule, an acid anhydride of the aliphatic compound and an esterified product of the aliphatic compound, for example, succinic acid, glutaric acid , Aliphatic polycarboxylic acids such as adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, octadecanedioic acid, citric acid; Anhydrides; lower alkyl esterified products of these aliphatic polyvalent carboxylic acids. An aliphatic polybasic acid can be used individually or in combination of 2 or more types.

  As the aliphatic polybasic acid, it is preferable to use a dicarboxylic acid having an alkyl chain having 4 to 18 carbon atoms. Examples of the dicarboxylic acid having an alkyl chain having 4 to 18 carbon atoms include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassic acid, and octadecanedioic acid. Among them, adipic acid can be preferably used.

  An aromatic polybasic acid is an aromatic compound having two or more carboxyl groups in one molecule, an acid anhydride of the aromatic compound and an esterified product of the aromatic compound, for example, phthalic acid, isophthalic acid , Terephthalic acid, naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, trimellitic acid, pyromellitic acid and other aromatic polycarboxylic acids; anhydrides of these aromatic polycarboxylic acids; And lower alkyl esterified acid. Aromatic polybasic acids can be used alone or in combination of two or more.

  As the alcohol component (a2), a polyhydric alcohol having two or more hydroxyl groups in one molecule can be preferably used. As said polyhydric alcohol, an alicyclic diol, an aliphatic diol, an aromatic diol etc. can be mentioned, for example.

  An alicyclic diol is a compound having one or more alicyclic structures (mainly 4- to 6-membered rings) and two hydroxyl groups in one molecule. Examples of the alicyclic diol include dihydric alcohols such as 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, hydrogenated bisphenol A, and hydrogenated bisphenol F; ε-caprolactone and the like in these dihydric alcohols. Examples include polylactone diol to which a lactone compound is added, and these can be used alone or in combination of two or more.

  An aliphatic diol is an aliphatic compound having two hydroxyl groups in one molecule. Examples of the aliphatic diol include ethylene glycol, propylene glycol, diethylene glycol, trimethylene glycol, tetraethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3 -Butanediol, 1,2-butanediol, 3-methyl-1,2-butanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-pentanediol, 1,5-pentanediol 1,4-pentanediol, 2,4-pentanediol, 2,3-dimethyltrimethylene glycol, tetramethylene glycol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3 -Pentanediol, 1,6-hexanediol, 1, -Hexanediol, 1,4-hexanediol, 2,5-hexanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, neopentyl glycol, etc. Or in combination of two or more.

  An aromatic diol is an aromatic compound having two hydroxyl groups in one molecule. Examples of the aromatic diol include ester diol compounds such as bis (hydroxyethyl) terephthalate; alkylene oxide adducts of bisphenol A and the like, and these can be used alone or in combination of two or more.

  Examples of other polyhydric alcohols other than the alicyclic diol, aliphatic diol and aromatic diol include, for example, polyether diol compounds such as polyethylene glycol, polypropylene glycol and polybutylene glycol; glycerin, trimethylol ethane and trimethylol propane. , Triglycerides such as diglycerin, triglycerin, 1,2,6-hexanetriol, pentaerythritol, dipentaerythritol, tris (2-hydroxyethyl) isocyanurate, sorbitol, mannitol; And a polylactone polyol compound obtained by adding a lactone compound such as ε-caprolactone to the alcohol.

  Among the other polyhydric alcohols, trihydric or higher alcohols can be suitably used from the viewpoint of increasing the molecular weight and improving the reactivity. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolethane, trimethylolpropane, diglycerin, triglycerin, 1,2,6-hexanetriol, pentaerythritol, dipentaerythritol, sorbitol, mannitol and the like. A trilactone (2-hydroxyethyl) isocyanurate, tris (2-hydroxypropyl) isocyanurate; a trilactone (2-hydroxyethyl) isocyanurate; a trilactone (2-hydroxypropyl) isocyanurate; And tris (hydroxyalkyl) isocyanurate such as tris (2-hydroxybutyl) isocyanurate. Of these, trimethylolpropane is particularly preferable.

  Examples of the alcohol component (a2) other than the polyhydric alcohol include monoalcohols such as methanol, ethanol, propyl alcohol, butyl alcohol, stearyl alcohol, and 2-phenoxyethanol; propylene oxide, butylene oxide, and synthetic highly branched saturated fatty acids. Alcohol compounds obtained by reacting a monoepoxy compound such as glycidyl ester (trade name “Cardura E10” manufactured by HEXION Specialty Chemicals) and an acid can be used as necessary.

  The production of the hydroxyl group-containing polyester resin is not particularly limited, and can be performed according to an ordinary method. For example, it is produced by reacting an acid component having the polybasic acid component as an essential component and an alcohol component at 150 to 250 ° C. for 5 to 10 hours in a nitrogen stream and performing an esterification reaction or a transesterification reaction. Can do.

  In the esterification reaction or transesterification reaction, the acid component and alcohol component may be added at once, or may be added in several portions. Moreover, after synthesize | combining a carboxyl group-containing polyester resin first, you may esterify some carboxyl groups in this carboxyl group-containing polyester resin using the said alcohol component. Furthermore, after first synthesizing the hydroxyl group-containing polyester resin, the acid anhydride may be reacted to half-esterify the hydroxyl group-containing polyester resin.

  In the esterification or transesterification reaction, a catalyst may be used to promote the reaction. As the catalyst, known catalysts such as dibutyltin dibenzoate, antimony trioxide, zinc acetate, manganese acetate, cobalt acetate, calcium acetate, tetrabutyl titanate, and tetraisopropyl titanate can be used.

  Further, the hydroxyl group-containing polyester resin can be modified with a fatty acid, an oil or fat, a polyisocyanate compound, an organopolysiloxane compound or the like during the preparation of the resin, or after the esterification reaction or the transesterification reaction.

  Alkyd resins can be obtained by modification with fatty acids or oils. By modifying with a polyisocyanate compound, a urethane-modified polyester resin is obtained. A silicon-modified polyester resin is obtained by modification with organopolysiloxane.

  Examples of fatty acids used in the production of the alkyd resin include coconut oil fatty acid, cottonseed oil fatty acid, hemp seed oil fatty acid, rice bran oil fatty acid, fish oil fatty acid, tall oil fatty acid, soybean oil fatty acid, linseed oil fatty acid, tung oil fatty acid, rapeseed oil fatty acid. And fatty acids such as castor oil fatty acid, dehydrated castor oil fatty acid, safflower oil fatty acid; lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid and the like. Examples of the fat include coconut oil, cottonseed oil, hemp seed oil, rice bran oil, fish oil, tall oil, soybean oil, linseed oil, tung oil, rapeseed oil, castor oil, dehydrated castor oil, safflower oil and the like.

  Examples of the polyisocyanate compound used for modifying the urethane-modified polyester resin include aliphatic diisocyanate compounds such as lysine diisocyanate, hexamethylene diisocyanate, and trimethylhexane diisocyanate; hydrogenated xylylene diisocyanate, isophorone diisocyanate, methylcyclohexane-2,4- Alicyclic diisocyanate compounds such as diisocyanate, methylcyclohexane-2,6-diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), 1,3- (isocyanatomethyl) cyclohexane; tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate Aromatic diisocyanate compounds such as lysine triisocyanate Organic polyisocyanates such as isocyanates themselves, adducts of these organic polyisocyanates with polyhydric alcohols, low molecular weight polyester resins or water, or cyclized polymers of the above-mentioned organic diisocyanates (for example, isocyanurates) ), Billet type adducts and the like. These can be used alone or in combination of two or more.

Examples of the organopolysiloxane compound used for modifying the silicon-modified polyester resin include organopolysiloxane (i) represented by the following formula (1) and organopolysiloxane (ii) having a hydrolyzable silyl group. .
R ² _a Si (OH) _b O _{(4-ab) / 2} Formula (1)
(Wherein R ² represents the same or different substituted or unsubstituted monovalent hydrocarbon having 1 to 8 carbon atoms, and a and b are 0.2 ≦ a ≦ 2, 0.1 ≦ b ≦ 3, a + b <4)
R ² is preferably an alkyl group having 1 to 4 carbon atoms, phenyl group, vinyl group, 3-glycidoxypropyl group (also referred to as γ-glycidoxypropyl group), 3-methacryloyloxypropyl group [γ- Substituted hydrocarbon groups such as methacryloyloxypropyl group], 3-aminopropyl group [also referred to as γ-aminopropyl group], 3,3,3-trifluoropropyl group, more preferably methyl group, ethyl group, etc. It is an alkyl group.

  Such an organopolysiloxane (i) is, for example, a large amount of methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, or one or a mixture of two or more alkoxysilanes corresponding thereto by a known method. It can be obtained by hydrolysis with water. Examples of commercially available organopolysiloxane (i) include KR-311, KR-282, and KR-271 (all manufactured by Shin-Etsu Chemical Co., Ltd., trade names).

  On the other hand, the organopolysiloxane (ii) is an organopolysiloxane having a hydrolyzable silyl group at the end or side chain of the molecule, and the hydrolyzable silyl group in the molecule, for example, an alkoxysilyl group is in the air. It is hydrolyzed by contact with moisture or the like to form a silanol group. As the organopolysiloxane (ii), a compound known per se can be used without limitation as long as it hydrolyzes and condenses at room temperature. As the organopolysiloxane (ii), those having a weight average molecular weight in the range of 200 to 28,000, particularly 300 to 18,000 are generally suitable. The number average molecular weight of the hydroxyl group-containing polyester resin used in the present invention is preferably from 1,000 to 30,000, particularly from 2,000 to 20,000, from the viewpoint of processability, chemical resistance and finish of the resulting coating film. It is preferred to have a number average molecular weight in the range of 000.

In this specification, the number average molecular weight and the weight average molecular weight are values obtained by converting the number average molecular weight and the weight average molecular weight measured using a gel permeation chromatograph (GPC) based on the molecular weight of standard polystyrene. .
Specifically, “HLC8120GPC” (trade name, manufactured by Tosoh Corporation) is used as a gel permeation chromatograph, and “TSKgel G-4000HXL”, “TSKgel G-3000HXL”, “TSKgel G-2500HXL” and columns are used. Four “TSKgel G-2000HXL” (trade name, all manufactured by Tosoh Corporation) can be used, and measurement can be performed under conditions of mobile phase tetrahydrofuran, measurement temperature of 40 ° C., flow rate of 1 mL / min, and detector RI.

  The hydroxyl value of the hydroxyl group-containing polyester resin is preferably in the range of 5 to 250 mgKOH / g, particularly 10 to 200 mgKOH / g, from the viewpoint of the processability of the coating film. The acid value of the hydroxyl group-containing polyester resin is preferably 30 mgKOH / g or less, more preferably 20 mgKOH / g or less, from the viewpoint of finish.

Melamine resin (B)
As the melamine resin (B), for example, a melamine resin obtained by etherifying a methylol group of a methylolated melamine resin with a monohydric alcohol having 1 to 8 carbon atoms can be used. The etherified melamine resin may be one in which all the methylol groups of the methylolated melamine resin are etherified, or may be partially etherified to leave a methylol group or imino group.

  Specific examples of the melamine resin (B) include fully alkyl type methyl / butyl mixed etherified melamine resin, methylol group type methyl / butyl mixed etherified melamine resin, imino type methyl / butyl mixed etherified melamine resin, fully alkyl type methyl. Mentioned melamine resin and imino group-type methylated melamine resin. Among these melamine resins (B), it is preferable to use a completely alkyl methylated melamine resin, in particular, in order to obtain a uniform crease pattern coating film on a metal plate. These melamine resins (B) may be used alone or in combination of two or more.

Commercially available products of the melamine resin (B) include, for example, fully alkyl type methyl / butyl mixed etherified melamine resins such as Cymel 232, Cymel 232S, Cymel 235, Cymel 236, Cymel 238, Cymel 266, Cymel 267, and Cymel 285; Methylol group methyl / butyl mixed etherified melamine resins such as Cymel 272; Cymel 202, Cymel 207, Cymel 212, Cymel 253, Cymel 254 and other imino methyl / butyl mixed etherified melamine resins; Cymel 300, Cymel 301, Cymel 303, fully alkyl type methylated melamine resins such as Cymel 350; Cymel 325, Cymel 327, Cymel 703, Cymel 712, Cymel 254, Cymel 253, Cymel 212, Cymel Imino group type methylated melamine resin, such as Le 1128 (manufactured by Nihon Cytec Industries Inc.), U-VAN 20SE60 (Mitsui Cytec Co., Ltd., butyl etherified melamine resins), and the like.

Blocked polyisocyanate compound (C)
In addition to the melamine resin (B), the glazing pattern paint of the present invention contains a blocked polyisocyanate compound (C) as a curing agent. The polyisocyanate compound in the blocked polyisocyanate compound (C) is a compound having two or more free isocyanate groups in one molecule, and examples thereof include aliphatics such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and dimer acid diisocyanate. Diisocyanate compounds; alicyclic diisocyanate compounds such as hydrogenated xylylene diisocyanate, cyclohexylene diisocyanate, methylenebis (cyclohexyl isocyanate), isophorone diisocyanate; tolylene diisocyanate, phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, tetramethyl Aromatic diisocyanates such as xylylene diisocyanate and naphthalene diisocyanate Anocyanate compound; 2-isocyanatoethyl-2,6-diisocyanatocaproate, 3-isocyanatomethyl-1,6-hexamethylene diisocyanate, 4-isocyanatomethyl-1,8-octamethylene diisocyanate (common name: triisone) And trivalent or higher organic polyisocyanate compounds such as aminononane triisocyanate). Examples thereof include cyclized polymers or burettes of these polyisocyanate compounds; or combinations thereof.

  Among these polyisocyanate compounds, an aliphatic polyisocyanate compound is desirable for obtaining a paint film having excellent processability, weather resistance and chemical resistance. Preferred are adducts of isocyanate compounds and burettes of aliphatic polyisocyanate compounds. Particularly preferred are hexamethylene diisocyanate nurate, hexamethylene diisocyanate compound adduct, and hexamethylene diisocyanate burette.

On the other hand, as a blocking agent for blocking the polyisocyanate compound, pyrazoles such as 3,5-dimethylpyrazole, 3-methylpyrazole, 4-nitro-3,5-dimethylpyrazole, 4-bromo-3,5-dimethylpyrazole, etc. Oximes such as methyl ethyl ketoxime, methyl amyl ketoxime and cyclohexanone oxime; phenols such as phenol, para-t-butylphenol and cresol; lactams such as ε-caprolactam and γ-butyrolactam; n-butanol, 2-ethylhexanol Aliphatic alcohols such as phenyl carbinol and methyl phenyl carbinol, etc .; Ether alcohols such as ethylene glycol monobutyl ether and diethylene glycol monoethyl ether Dimethyl malonate, diethyl malonate, ethyl acetoacetate, methyl acetoacetate, active methylene compounds such as acetylacetone; and the like.
Among these blocking agents, pyrazoles, oximes, phenols and lactams are desirable in order to obtain a crease-patterned coating film excellent in chemical resistance, processability and weather resistance, and oximes are particularly preferable.

  Commercially available products of the block polyisocyanate compound (C) include, for example, Barnock D-500, Barnock D-550, Barnock DB-980K (above, DIC Corporation, trade name), Sumijour N3300, Death Module N3600, Death Hexamethylene diisocyanate nurate such as Module N3790BA, Death Module N3900, and Death Module XP2840; Hexamethylene diisocyanate burette such as Death Module N75MPA / X and Death Module N3200; Adduct of hexamethylene diisocyanate such as Death Module HT , Manufactured by Sumika Bayer Urethane Co., Ltd., trade name), Takenate D-102, Takenate D-202, Takenate D-110N or Takenate D-123N (or more Mitsui Chemicals, trade name), Coronate L, Coronate HL, Coronate EH, Coronate 203, Millionate MT (manufactured by Nippon Polyurethane Industry, trade name), Duranate MF-K60B, SBN-70D, MF-B60B, 17B-60P , TPA-B80E, E402-B80B (trade name, manufactured by Asahi Kasei Chemicals Corporation) and the like.

  The mixing ratio of the hydroxyl group-containing resin (A), the melamine resin (B), and the block polyisocyanate compound (C) is the solid content of the component (A), the component (B), and the component (C). Based on a total amount of 100 parts by mass, the solid content is 50 to 90 parts by mass of the hydroxyl group-containing resin (A), preferably 60 to 85 parts by mass, and 8 to 25 parts by mass of the melamine resin (B), preferably 10 to 22 parts by mass. The block polyisocyanate compound (C) is preferably 2 to 25 parts by mass, preferably 5 to 18 parts by mass in order to obtain a crease-patterned coating film having excellent processability, weather resistance and chemical resistance.

Sulfonic acid compound (D)
The sulfonic acid compound (D) used in the glazing pattern paint of the present invention is a catalyst that accelerates the curing reaction between the hydroxyl group-containing resin (A) and the melamine resin (B). Examples of the sulfonic acid compound (D) include dodecylbenzenesulfonic acid, paratoluenesulfonic acid, methanesulfonic acid, dinonylnaphthalenesulfonic acid, and dinonylnaphthalenedisulfonic acid. These can be used alone or in admixture of two or more. In particular, dodecylbenzenesulfonic acid is preferred for the formation of a uniform texture pattern coating film.

Amine compound (E)
Examples of the amine compound (E) used for the paint pattern of the present invention include diethylamine, diisopropylamine, di-n-propylamine, diallylamine, diamylamine, di-n-butylamine, diisobutylamine, di-sec-butylamine, N-ethyl-1,2-dimethylpropylamine, N-methylhexylamine, di-n-octylamine, piperidine, 2-pipecoline, 3-pipecholine, 4-pipecholine, 2,4-, 2,6-, 3 , 5-Lupetidine, secondary amines such as 3-piperidinemethanol; triethylamine, tributylamine, triallylamine, N-methyldiallylamine, N-methylmorpholine, N, N, N ′, N′-tetramethyl-1,2 -Diaminoethane, N-methylpiperidine, pyridine, 4-ethylpi Examples include tertiary amines such as lysine; amines having secondary and tertiary amino groups such as N-methylpiperazine, and the like. These can be used alone or as a mixture of two or more.

  In the amine compound (E), the boiling point, type and addition amount are important for obtaining a uniform crease pattern coating film. The boiling point of the amine compound (E) is 30 to 250 ° C, preferably 70 to 160 ° C, more preferably 75 to 110 ° C. The kind of the amine compound (E) is preferably triethylamine, diisopropylamine and di-n-propylamine. The addition amount of the amine compound (E) is preferably in the range of amine compound (E) / sulfonic acid compound (D) = 1.5 to 30 (molar ratio), particularly 5 to 22 (molar ratio).

  The sulfonic acid compound (D) and the amine compound (E) may be mixed in advance, or a mixture thereof may be blended. A blocked sulfonic acid compound obtained by blocking a sulfonic acid with a secondary or tertiary amine compound can also be used, and can be used in combination with the amine compound (E).

  Commercially available blocked sulfonic acid compounds include, for example, Neicure 5225 (manufactured by King Industries, amine neutralized solution of dodecylbenzenesulfonic acid, content of dodecylbenzenesulfonic acid is 25%), Neicure N2500 (King Industries) Izu Co., Ltd., an amine neutralized solution of paratoluenesulfonic acid, and a content of paratoluenesulfonic acid of 25%).

  The blending amount of the sulfonic acid compound (D) used in the glazing pattern paint of the present invention is 0 based on the total solid content of 100 parts by mass of the hydroxyl group-containing resin (A), the melamine resin (B) and the block polyisocyanate compound (C). 0.1 to 3.0 parts by mass, preferably 0.2 to 2.5 parts by mass, and more preferably 0.5 to 2.0 parts by mass is necessary for the formation of a uniform texture pattern coating film. .

  In addition to the hydroxyl group-containing resin (A), the melamine resin (B), the blocked polyisocyanate compound (C), the sulfonic acid compound (D), and the amine compound (E), the wrinkle pattern paint of the present invention includes nylon resin particles, Organic resin particles such as acrylic resin particles and urethane resin particles; inorganic powders such as silica fine powder; pigments such as colored pigments, glitter pigments, extender pigments, rust preventive pigments; antifoaming agents, surface conditioners, ultraviolet absorbers, Additives for paints such as light stabilizers and waxes; Antifouling agents such as organic silicates; Dissociation catalysts for blocked isocyanates such as organic tin compounds; Use of known raw materials conventionally used in paint compositions such as organic solvents can do.

About the coating film formation method using a crease pattern paint The coating film formation method using the crease pattern paint of the present invention is performed by applying a primer paint on one side or both sides of a metal plate as necessary. And a paint film with a crease pattern paint is formed on at least one side of the metal plate and / or the primer paint film.

The metal plate is a cold-rolled steel plate, hot-dip galvanized steel plate, electrogalvanized steel plate, alloy galvanized steel plate (alloy galvanized steel plate such as iron-zinc, aluminum-zinc, nickel-zinc), aluminum plate, stainless steel plate, copper plate , Copper plated steel plate, tin plated steel plate and the like.
The metal plate may be painted as it is if the surface is not contaminated with oil or other contaminants. However, a known metal surface treatment may be applied to improve adhesion and corrosion resistance with the coating film. desirable. These known surface treatment methods include phosphate surface treatment, chromate surface treatment, zirconium surface treatment and the like.

  As the primer paint, for example, a known primer paint used in the colored color steel sheet coating field, the industrial machine coating field, the metal part coating field and the like can be applied. The primer paint is appropriately selected depending on the type of material to be coated and the type of metal surface treatment, and in particular, an epoxy resin primer paint, a polyester resin primer paint and their modified primer paint are suitable, and workability is particularly required. In this case, a polyester-based primer paint is preferable. From the viewpoint of environmental protection, it is preferable to use a chromium-free primer coating that does not contain a chromium-based rust preventive component.

  The primer coating is applied by a known coating method such as roll coating or spray coating so that the dry film thickness is 1 to 30 μm, preferably 2 to 20 μm, and the maximum material reaching temperature is 140 to 250 ° C., preferably The cured primer coating film can be formed by heating at a temperature of 200 to 240 ° C. for 5 seconds to 120 seconds, preferably 10 to 60 seconds.

  The primer coating film may be a single layer or two layers in which a second primer coating film (intermediate coating film) is formed on the first primer coating film. When the primer coating has two layers, the first primer coating has an anticorrosion function, and the second primer coating (intermediate coating) has processability and chipping resistance. Different functions can also be imparted to the primer coating.

  The glazing pattern paint of the present invention is applied on at least one side of the metal plate or primer coating. Examples of the coating method include coil coat coating, immersion coating, and spray coating.

  When the glazing pattern paint of the present invention is applied by coil coating, there is no limitation on the coating method, but curtain coating or roll coating is recommended for economic reasons. When roll coat coating is applied, the bottom feed method (so-called reverse coating or natural coating) with a normal two-roll is suitable for practical use, but three for improving the uniformity of the coating surface. A top feed or bottom feed method using a roll can also be performed.

  The heat-drying of the wrinkle pattern paint of the present invention is usually at a material maximum temperature of 160 to 260 ° C., preferably 200 to 240 ° C., for 5 to 90 seconds, preferably 10 to 60 seconds. The dry film thickness of the paint pattern is preferably 5 to 50 μm, more preferably 10 to 35 μm.

  The obtained glazing pattern coating film can have a 60-degree specular gloss of 10 or less, particularly 7 or less. The 60-degree specular gloss is a value specified in JIS K 5600-4-7 (1999). The reflectivity when the incident angle is 60 degrees is measured, and the gloss of the reference surface for the specular gloss is measured. It is a value expressed as a percentage when the degree is 100.

  Hereinafter, the present invention will be described in more detail with reference to Production Examples, Examples, and Comparative Examples, but the present invention is not limited thereto. In the following description, “part by mass” is abbreviated as “part”, and “mass%” is abbreviated as “%”.

Production of hydroxyl-containing polyester resin
Production Example 1 Polyester resin no. Preparation of 1 solution Thermometer, stirrer, heating device and rectifying tower were charged with 1079 parts isophthalic acid, 407 parts adipic acid, 466 parts neopentyl glycol and 802 parts trimethylolpropane and heated to 160 ° C. Then, the temperature was gradually raised from 160 ° C. to 230 ° C. over 3 hours. Next, after continuing the reaction at 230 ° C. for 30 minutes, the rectifying column was replaced with a water separator, and 124 parts of xylene was added to the contents, and xylene was also added to the water separator to azeotrope water and xylene. The condensed water was removed, the reaction was allowed to proceed until the acid value reached 10 mgKOH / g, the mixture was cooled, and the solid content was adjusted by adding cyclohexanone to the reaction product.
One solution was obtained. The obtained polyester resin No. 1 is a hydroxyl value of 184 mg KOH / g,
It had a number average molecular weight of 3,400.

Production Example 2 Polyester Resin No. Production of two solutions
A reactor equipped with a thermometer, a stirrer, a heating device and a rectifying tower was charged with 740 parts of phthalic anhydride, 498 parts of isophthalic acid, 145 parts of adipic acid, 735 parts of neopentyl glycol and 236 parts of 1.6-hexanediol. The temperature was raised to 160 ° C., and the temperature was gradually raised from 160 ° C. to 230 ° C. over 3 hours.
Next, after continuing the reaction at 230 ° C. for 30 minutes, the rectifying column is replaced with a water separator,
Add 90 parts of xylene to the contents, add xylene to the water separator, azeotrope water and xylene to remove condensed water, react until the acid value is 10 mgKOH / g, cool, and react The solid content was adjusted by adding cyclohexanone to polyester resin No. 5 having a solid content of 55%. Two solutions were obtained. The obtained polyester resin No. 2 had a hydroxyl value of 79 mg KOH / g and a number average molecular weight of 2,000.

Production Example 3 Production of Acrylic Resin Solution A reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser and dropping device was charged with 480 parts of butyl acetate and heated to 130 ° C. while blowing nitrogen gas. While holding, from the dropping device, 200 parts of styrene, 290 parts of methyl methacrylate, 250 parts of cyclohexyl methacrylate, 260 parts of 2-hydroxyethyl methacrylate and 2
, 2′-azobis (2-methylbutyronitrile 50 parts) was added dropwise over 3 hours. After completion of dropping, the reaction product was aged at 130 ° C. for 1 hour, and the solid content was adjusted with cyclohexanone to obtain an acrylic resin solution having a resin solid content of 55%. The resulting acrylic resin has a hydroxyl value of 1
It had 07 mg KOH / g and a number average molecular weight of 8,000.

Production Example 4 Polyisocyanate Compound No. 4 Example 1 1 (Phenol-blocked hexamethylene diisocyanate nurate) A reaction vessel equipped with a thermometer, thermostat, stirrer, and reflux condenser was placed in a nitrogen atmosphere, and then 100 parts of Sumijour N3300 (Note 1) were dehydrated. 64.4 parts of diethylene glycol dimethyl ether was charged and heated to 40 ° C.
Subsequently, 50.3 parts of phenol was added, and the mixture was sampled over time while being heated to 130 ° C. and kept at that temperature, and reacted until no isocyanate group was detected by measuring FT-IR. Thereafter, the solid content was adjusted with diethylene glycol dimethyl ether to prepare a polyisocyanate compound No. 5 having a solid content of 50%. 1 was obtained.
(Note 1) Sumidur N3300: manufactured by Sumika Bayer Urethane Co., Ltd., trade name, nurate of hexamethylene diisocyanate, NCO 21.8%.

Production Example 5 Polyisocyanate Compound No. 2 (caprolactam-blocked hexamethylene diisocyanate nurate) Preparation of a reaction vessel equipped with a thermometer, thermostat, stirrer and reflux condenser in a nitrogen atmosphere, 100 parts of Sumijour N3300 (Note 1), dehydration 72.0 parts of diethylene glycol dimethyl ether was heated and heated to 40 ° C.
Next, 67.9 parts of ε-caprolactam was added, and the mixture was sampled over time while being heated to 130 ° C. and maintained at that temperature, and reacted until no isocyanate group was detected by measuring FT-IR. Thereafter, the solid content was adjusted with diethylene glycol dimethyl ether to prepare a polyisocyanate compound No. 5 having a solid content of 50%. 2 was obtained.

Production Example 6 Polyisocyanate Compound No. 3 (Methyl ethyl ketoxime-blocked hexamethylene diisocyanate burette body) A reaction vessel equipped with a thermometer, thermostat, stirrer and reflux condenser was put in a nitrogen atmosphere, and then 100 parts of Desmodur N3200 (Note 2), dehydrated 63.9 parts of methyl isobutyl ketone was charged and heated to 80 ° C. Next, 49.1 parts of methyl ethyl ketoxime was added over 1 hour, sampled over time while maintaining 80 ° C., and reacted until no isocyanate group was detected by measuring FT-IR, followed by solid content with methyl isobutyl ketone. To adjust the polyisocyanate compound No. 5 having a solid content of 50%. 3 was obtained.
(Note 2) Desmodule N3200: manufactured by Sumika Bayer Urethane Co., Ltd., trade name, hexamethylene diisocyanate burette body.

Example 1 Coating composition no. 1 production
145.5 parts of polyester resin solution obtained in Production Example 1 (80 parts in solid content), 15 parts of Cymel 303 (Note 4), 5 parts of Desmodur BL-3575 (Note 6), 0.3 part of dodecylbenzenesulfonic acid , 2 parts of triethylamine, 0.3 part of formate TK-1 (Note 10), 80 parts of Type CR-95 (Note 11), 3 parts of Carbon MA-100 (Note 12) and an organic solvent (cyclohexanone / swazole 1500 = 40 / 60 (mass ratio) mixed solvent) and diluted to a coating composition No. having a viscosity of 80 seconds (Ford Cup # 4, 25 ° C.). 1 was obtained.

Examples 2 to 24 Coating composition No. 2-No. 24 manufacturing
Except for the contents shown in Tables 1 and 2, the coating composition No. 2
~ No. 24 was obtained. In Tables 1 and 2, the amounts of the component (A), the component (B), and the component (C) are expressed as solid contents.

(Note 3) Byron KS-1520V: manufactured by Toyobo Co., Ltd., hydroxyl value 42 mgKOH / g, number average molecular weight 6,400, polyester resin (Note 4) Cymel 303: manufactured by Nippon Cytec Industries, Ltd., trade name, complete Alkyl-type methylated melamine resin (Note 5) Cymel 232S: Nippon Cytec Industries, Ltd., trade name, fully alkyl-type methyl / butyl mixed etherified melamine resin (Note 6) Death module BL-3575: manufactured by Sumika Bayer Urethane Co., Ltd. Product name, pyrazole blocked, hexamethylene diisocyanate nurate (Note 7) Sumidur BL3175: Sumika Bayer Urethane Co., Ltd., trade name, methyl ethyl ketoxime blocked, hexamethylene diisocyanate nurate (Note 8) deuranate E40 2-B80T: Asahi Kasei Chemicals, trade name, methyl ethyl ketoxime blocked, adduct of hexamethylene diisocyanate (Note 9) Compound A: triethylamine block of dodecylbenzenesulfonic acid, amine compound (E) / sulfonic acid compound (D ) Molar ratio of 9.7
(Note 10) Formate TK-1: Takeda Pharmaceutical Company Limited, trade name, organotin catalyst (Note 11) Type CR-95: Ishihara Sangyo Co., Ltd. trade name, Titanium White (Note 12) Carbon MA- 100: Mitsubishi Kasei Co., Ltd., trade name, carbon black (Note 13) Silicia 310: Fuji Silysia, trade name, fine particle silica.

Comparative Examples 1-13 Coating Composition No. 25-No. 37 creation
Except for the contents shown in Table 3, the coating composition No. 25-No. 37 was obtained. In Table 3, the amounts of the component (A), the component (B), and the component (C) are expressed as solid contents.

Creating test plates
A primer coating film (KP color 8625 primer, manufactured by Kansai Paint Co., Ltd., trade name) having a dry film thickness of 5 μm was formed on an aluminum-zinc alloy galvanized steel sheet (GL material, plate thickness 0.35 mm).
Subsequently, on the said primer coating film, coating composition No. obtained in the said Example and comparative example. 1-No. 37 was coated with a roll coater so as to have a dry film thickness of 18 μm, and baked for 40 seconds under the condition that the maximum material arrival temperature was 220 ° C. to obtain each test plate. Tables 1 to 3 show the results of testing according to the test conditions described later using each test plate.

(Note 14) Finishing properties of the itch pattern coating film:
The appearance of the test plate was observed with the naked eye and evaluated according to the following criteria.
In ◎, the coating surface has a feeling of unevenness, and a dense and uniform crease pattern occurs. (See Figure 1)
○ indicates that a wrinkled pattern with a feeling of unevenness is generated on the coated surface, but the denseness or uniformity of the wrinkled pattern is slightly inferior to the above test plate of A. (See Figure 2)
Δ shows a wrinkle pattern on the coated surface, but the denseness or uniformity of the wrinkle pattern is inferior to the above test plate of ○. (See Figure 3)
×: shrinkage pattern does not occur on the painted surface. (See FIG. 4).

(Note 15) Workability:
In a room at 20 ° C., a test plate was bent 180 degrees with a metal plate having a thickness of 0.35 mm sandwiched therebetween and the coating surface facing outward, and the degree of cracking in the coating film at the bent portion was evaluated.
◎: No cracking in 2T (two metal plates sandwiched) bending process
○ indicates cracking in 2T (two metal plates sandwiched between) bending, but cracking is not observed in 4T bending
Δ is cracked in 4T bending process (four metal plates sandwiched between), but cracking is not recognized in 6T folding process.
In x, bending is recognized in 6T (six metal plates sandwiched therebetween) bending process.

(Note 16) Accelerated weather resistance:
For each test plate, the long-term durability of the coating film specified in JIS K 5600 7.7. Based on the accelerated weather resistance (xenon lamp method) test A method, xenon under repeated cycle conditions (wet 18 minutes-dry 102 minutes) Irradiation for 3,000 hours was performed with a weather meter. Then, in each test board, the coating surface state was evaluated based on the following content.
In ◎, no abnormalities on the coating surface such as swelling, cracking, cloudiness, and choking are observed.
○ indicates that there are no paint surface abnormalities such as swelling, cracking or choking on the paint surface, but cloudiness is observed on the paint surface. △ indicates any of the paint surface abnormalities such as swelling, cracking or choking on the paint surface. Is accepted
In x, any of the coating surface abnormalities such as swelling, cracking or choking is remarkably recognized on the coating surface.

(Note 17) Chemical resistance:
Each test plate was cut into a size of 70 × 150 mm, the back surface and the cut surface were sealed with a rust preventive paint, and a cross cut reaching the substrate was put in the center of the front (front) surface side. This test plate was immersed in a 5% aqueous sodium hydroxide solution at 30 ° C. for 48 hours, then taken out, washed, and a cellophane adhesive tape was adhered to the cross cut part, and the peel width from the cut part in the coating film after abrupt peeling. (One side) was evaluated.
◎ indicates that the tape peeling width from the cut part is 2.0 mm or less,
○, the tape peeling width from the cut part exceeds 2.0 mm and 3 mm or less,
△ indicates that the tape peeling width from the cut part exceeds 3 mm and 4 mm or less,
In x, the tape peeling width from the cut part exceeds 4 mm.

  (Note 18) 60 degree specular gloss: The reflectivity when the incident angle is 60 degrees is measured according to the degree of gloss of the test plate according to the 60 degree specular gloss of JIS K 5600-4-7 (1999). , And expressed as a percentage when the glossiness of the reference surface of the specular glossiness is taken as 100.

  It is possible to provide a coated steel sheet in which a paint film is formed on a metal plate and is excellent in workability, weather resistance, and chemical resistance.

It is a “◎” level itch pattern coating film evaluated using a 3D image processing system (XG series) manufactured by Keyence Corporation. It is a "*" level itch pattern coating film evaluated using a 3D image processing system (XG series) manufactured by Keyence Corporation. It is a “Δ” level itch pattern coating film evaluated using a 3D image processing system (XG series) manufactured by Keyence Corporation. This is a “×” level itch pattern coating film evaluated using a 3D image processing system (XG series) manufactured by Keyence Corporation.

Claims (9)

A coating composition containing a hydroxyl group-containing resin (A), a melamine resin (B), a blocked polyisocyanate compound (C), a sulfonic acid compound (D) and an amine compound (E), the hydroxyl group-containing resin (A), Based on the total solid content of 100 parts by mass of the melamine resin (B) and the blocked polyisocyanate compound (C), the component (A) is 50 to 90 parts by mass, the component (B) is 8 to 25 parts by mass, and the component ( 2) to 25 parts by mass of C), 0.1 to 3.0 parts by mass of component (D), and the amine compound (E) / sulfonic acid compound (D) molar ratio is 1.5 to 30 A paint composition capable of forming a itch pattern coating film characterized by The coating composition according to claim 1, wherein the hydroxyl group-containing resin (A) is a hydroxyl group-containing polyester resin. The coating composition according to claim 1 or 2, wherein the melamine resin (B) is a fully alkyl type methylated melamine resin. The coating composition according to any one of claims 1 to 3, wherein the blocked polyisocyanate compound (C) is a blocked product of an aliphatic polyisocyanate compound. The coating composition according to any one of claims 1 to 4, wherein the blocking agent in the blocked polyisocyanate compound (C) is at least one selected from pyrazoles, oximes, phenols and lactams. The coating composition according to any one of claims 1 to 5, wherein the amine compound (E) has a boiling point of 30 to 250 ° C. Hydroxyl-containing polyester resin, fully alkyl-type methylated melamine resin, aliphatic polyisocyanate nurate methylethyl ketoxime blocked product, dodecylbenzenesulfonic acid and triethylamine-containing coating composition, hydroxyl-containing polyester resin, fully alkyl-type methyl 50 to 90 parts by mass of a hydroxyl group-containing polyester resin and 8 to 25 of a fully alkyl type methylated melamine resin, based on 100 parts by mass in total of the solid content of the methyl ethyl ketoxime blocked product of a nucleated melamine resin and an aliphatic polyisocyanate nurate. Part by weight, 2-25 parts by weight of a methyl ethyl ketoxime blocked product of an aliphatic polyisocyanate nurate, 0.1-3.0 parts by weight of dodecylbenzenesulfonic acid, and triethylamine / dodecylbe Wrinkle pattern coating film formable coating composition molar ratio of Zensuruhon acid characterized in that it is a 1.5 to 30. The coating composition according to any one of claims 1 to 7, on the primer coating film of the article to be coated, wherein the primer coating film is formed on a metal plate that may be subjected to chemical conversion treatment on the surface. A method of forming a itch pattern coating film characterized by painting and baking an object. A coated metal sheet obtained by the coating film forming method according to claim 8.

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