JP2013053304A - Thermosetting two-pot type coating material composition and coated article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating material composition excellent in low-temperature curability, finishing state, coated film hardness, stability of a matte coated film, water resistance, corrosion resistance and weatherability; and to provide a coated article.SOLUTION: This thermosetting two-pot type coating material composition includes a hydroxy group-containing resin (A), a polyisocyanate compound (B), barium sulfate (C) with average particle diameter of 1.0-15 μm, silica microparticles (D), and rheology-controlling agent (E), at rates of 60-90 pts.mass of the hydroxy group-containing resin (A) and 10-40 pts.mass of polyisocyanate compound (B) based on 100 pts.mass of total solid content of the hydroxy group-containing resin (A) and the polyisocyanate compound (B), and further at rates of 1-150 pts.mass of barium sulfate (C), 0.1-30 pts.mass of silica microparticles (D) and 0.1-20 pts.mass of a rheology-controlling agent (E).

Description

  The present invention relates to a thermosetting two-component coating composition and a coated article excellent in low-temperature curability, finish, coating film hardness, gloss stability of a matte coating film, water resistance, corrosion resistance and weather resistance.

  Recently, various coating compositions are used for coating construction machines or industrial machines such as bulldozers, hydraulic excavators, and wheel loaders. However, the construction machine or the industrial machine has the following problems when the coating film is dried: The heat capacity of the object to be coated is large, and the heat of the drying furnace is not sufficiently transmitted, and the curability is not sufficient. 2. There are many vertical parts, and the glossiness of the matte coating is not stable. 3. Furthermore, since construction machines or industrial machines are used outdoors, there are problems such as requiring coating film hardness, water resistance, corrosion resistance, and weather resistance.

  Conventionally, a specific epoxy ester resin (a) 5 to 60% by weight and an oil length of 40 to 70% alkyd resin composition (b) 40 to 95% by weight are mixed and then heated, and then an acrylic monomer (c ) Is added to the resin composition (A) obtained by reaction, and a coating composition is disclosed in which a solvent and a colorant are added. Large-scale civil engineering machines such as bulldozers and power shovels; Large-scale machinery for use; it is described that it can be suitably used for painting large agricultural machinery such as tractors and combines (Patent Document 1).

  Further, it is a two-component curable aqueous coating composition comprising an aqueous main agent (I) containing a hydroxyl group-containing resin and a curing agent (II), and the aqueous main agent (I) has a hydroxyl value of 50 to 200 mgKOH / g, an acid value of 10 to 100 mgKOH / g, and an aqueous polymer polyol having a number average molecular weight of 1000 to 100,000, the curing agent (II) is a polyisocyanate having water dispersibility, and a solubility parameter of 8 A two-component curable composition containing an organic solvent inactive with respect to an isocyanate group at 0.0 to 10.0 is disclosed (Patent Document 2).

In addition, it is a paint containing polyester resin (A), acrylic resin (B), water-dispersible polyisocyanate compound (C) and ion-exchanged amorphous silica fine particles (D), and has a long pot life, A two-component coating material capable of forming a coating film excellent in hardness, finish, gloss, water resistance and corrosion resistance is disclosed (Patent Document 3).
However, the coating compositions of Patent Documents 1 to 3 have problems in any of low-temperature curability, finish, coating film hardness, matte coating stability, water resistance, corrosion resistance, and weather resistance. It was insufficient to achieve.

Japanese Patent Laid-Open No. 10-77442 JP 2006-257141 A JP 2007-284480 A

  The problems to be solved by the present invention are low-temperature curability, finish, coating film hardness, gloss stability of matte coating film, thermosetting two-component coating composition excellent in water resistance, corrosion resistance and weather resistance, and It is to provide a coated article.

  As a result of intensive studies, the inventors have found that the hydroxyl group-containing resin (A), the polyisocyanate compound (B), barium sulfate (C) having an average particle diameter of 1.0 to 15 μm, silica fine particles (D), and a rheology control agent ( The present inventors have found that the above-mentioned problems can be solved by the thermosetting two-component coating composition containing E), and have completed the present invention.

That is, the present invention relates to the following items:
1. A composition containing a hydroxyl group-containing resin (A), a polyisocyanate compound (B), barium sulfate (C) having an average particle size of 1.0 to 15 μm, silica fine particles (D), and a rheology control agent (E). ,
A ratio of 60 to 90 parts by mass of the hydroxyl group-containing resin (A) and 10 to 40 parts by mass of the polyisocyanate compound (B) based on 100 parts by mass of the total solid content of the hydroxyl group-containing resin (A) and the polyisocyanate compound (B). And 2 thermosetting liquids containing 1 to 150 parts by mass of barium sulfate (C), 0.1 to 30 parts by mass of silica fine particles (D), and 0.1 to 20 parts by mass of rheology control agent (E). Mold paint composition.

  2. Thermosetting 2 of 1 which contains 0.1-30 mass parts of polyether polyol (F) on the basis of 100 mass parts of solid content total of hydroxyl-containing resin (A) and polyisocyanate compound (B). Liquid paint composition.

  3. 3. The thermosetting two-component coating composition according to item 1 or 2, wherein the rheology control agent (E) is a urethane urea rheology control agent.

  4). 4. The thermosetting two-component coating composition according to any one of items 1 to 3, wherein the hydroxyl group-containing resin (A) is a hydroxyl group-containing acrylic resin.

  5. The thermosetting two-component coating composition according to items 1 to 4, which is a coating material for construction machinery or industrial machinery.

  6). A step of applying the thermosetting two-component coating composition according to any one of items 1 to 5 without applying an undercoating paint to the article to be coated, or the two thermosetting liquids A coating method for a coating material, comprising a step of baking and drying a coating material coated with a mold coating composition at 50 to 170 ° C. for 10 to 120 minutes.

  A coated article having a coating film obtained by the coating method described in 7.6, wherein the coated film has a 60-degree specular gloss of 10 to 70.

  8). 8. The coated article according to item 7, wherein the article to be coated is a construction machine or an industrial machine.

  The thermosetting two-component coating composition of the present invention is excellent in coating stability. 1. Even a coated object having a large heat capacity can be sufficiently cured at a low temperature in a short time. 2. A stable matte coating can be obtained even in a vertical region. It has effects such as being able to form a coating film excellent in water resistance, corrosion resistance, weather resistance and the like. Therefore, it is also useful for outdoor use, and can be suitably used, for example, as a paint for construction machinery or industrial machinery.

The reason why the effect of the present invention is obtained is a thermosetting two-component coating composition using polyisocyanate as a crosslinking agent, and has low temperature curability.
Further, it contains barium sulfate (C) having an average particle size of 1.0 to 15 μm, silica fine particles (D), and the ratio of the (C) component / (D) component is adjusted, and the rheology control agent (E) Due to the synergistic effect, it is possible to obtain a stable matte coating film without being affected by the baking temperature and without changing the matting degree even in the vertical part. The reason for this is that in the coating film, the silica fine particles (D) enter the barium sulfate (C) having an average particle diameter of 1.0 to 15 μm to control the flow, and the flow control is further suppressed by the rheology control agent (E). Therefore, the matte degree is considered to be stable.

  It is considered that the coating density excellent in water resistance, corrosion resistance, weather resistance, and the like is obtained by improving the crosslinking density of the coating film by the optimum blending ratio of the hydroxyl group-containing resin (A) and the polyisocyanate compound (B). Furthermore, when polyether polyol (F) is mix | blended, the said polyether polyol (F) adjusts a coating-film physical property and contributes to the further improvement of coating-film performance.

  The present invention is a heat containing a hydroxyl group-containing resin (A), a polyisocyanate compound (B), barium sulfate (C) having an average particle size of 1.0 to 15 μm, silica fine particles (D), and a rheology control agent (E). The present invention relates to a curable two-component coating composition, and further relates to a thermosetting two-component coating composition containing a polyether polyol (F) other than the hydroxyl group-containing resin (A) as necessary. Details will be described below.

  The thermosetting two-component coating composition of the present invention comprises a hydroxyl group-containing resin (A), barium sulfate (C) having an average particle size of 1.0 to 15 μm, silica fine particles (D), and a rheology control agent (E). It consists of a main agent (I) containing and a curing agent (II) containing a polyisocyanate compound (B). The thermosetting two-component coating composition of the present invention includes those in which the main agent (I) and the curing agent (II) are not mixed and those in which these are mixed.

Hydroxyl-containing resin (A):
The hydroxyl group-containing resin (A) is a resin having at least one hydroxyl group in one molecule. Examples of the hydroxyl group-containing resin (A) include resins having a hydroxyl group, such as polyester resins, acrylic resins, polycarbonate resins, polyurethane resins, epoxy resins, and alkyd resins. These can be used alone or in combination of two or more. Especially, it is preferable that a hydroxyl-containing resin (A) is a hydroxyl-containing acrylic resin from the point of the weather resistance of the coating film obtained. The hydroxyl group-containing resin (A) does not include the polyether polyol (F) described later.

  The hydroxyl group-containing acrylic resin is usually prepared by a hydroxyl group-containing polymerizable unsaturated monomer and other polymerizable unsaturated monomers copolymerizable with the hydroxyl group-containing polymerizable unsaturated monomer in a manner known per se, for example, in an organic solvent. It can manufacture by making it copolymerize by methods, such as the solution polymerization method of this, and the emulsion polymerization method in water.

  The hydroxyl group-containing polymerizable unsaturated monomer is a compound having at least one hydroxyl group and one polymerizable unsaturated bond in one molecule. Specifically, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxy Propyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 7-hydroxyheptyl (meta ) Monoesterified product of (meth) acrylic acid such as acrylate and 8-hydroxyoctyl (meth) acrylate and a dihydric alcohol having 2 to 8 carbon atoms (preferably 2 to 4 carbon atoms); (meth) acrylic acid and carbon number Ε-caprolactone modified product of monoesterified product with 2-8 dihydric alcohol N- hydroxymethyl (meth) acrylamide; allyl alcohol, furthermore, may be mentioned molecular ends having a polyoxyethylene chain is a hydroxyl group (meth) acrylate. In the present invention, the polymerizable unsaturated monomer having an ultraviolet absorbing functional group such as 2-hydroxy-4- (3-methacryloyloxy-2-hydroxypropoxy) benzophenone described later is a hydroxyl group-containing polymerizable unsaturated monomer. Instead, it is included in other polymerizable unsaturated monomers copolymerizable with a hydroxyl group-containing polymerizable unsaturated monomer.

  Examples of the other polymerizable unsaturated monomer copolymerizable with the hydroxyl group-containing polymerizable unsaturated monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl ( (Meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) Acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, “isostearyl acrylate” (trade name, manufactured by Osaka Organic Chemical Industry Co., Ltd.), cyclohexyl (meth) acrylate, methyl Cyclohexyl Alkyl or cycloalkyl (meth) acrylate such as (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate; polymerizable unsaturated monomer having an isobornyl group such as isobornyl (meth) acrylate; adamantyl ( Polymerizable unsaturated monomers having an adamantyl group such as (meth) acrylate; vinyl aromatic compounds such as styrene, α-methylstyrene and vinyltoluene; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, polymerizable unsaturated monomers having alkoxysilyl groups such as γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane; Perfluoroalkyl (meth) acrylates such as (meth) acrylate and perfluorooctylethyl (meth) acrylate; polymerizable unsaturated monomers having a fluorinated alkyl group such as fluoroolefin; and having a photopolymerizable functional group such as a maleimide group Polymerizable unsaturated monomers; vinyl compounds such as N-vinylpyrrolidone, ethylene, butadiene, chloroprene, vinyl propionate and vinyl acetate; carboxyl groups such as (meth) acrylic acid, maleic acid, crotonic acid and β-carboxyethyl acrylate Polymerizable unsaturated monomer: (meth) acrylonitrile, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylamide, amine compound with glycidyl (meth) acrylate Containing nitrogen-containing polymerizable unsaturated monomers such as adducts; and polymerizable unsaturated groups having at least two polymerizable unsaturated groups such as allyl (meth) acrylate and 1,6-hexanediol di (meth) acrylate in one molecule. Saturated monomer: glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl ( Epoxy group-containing polymerizable unsaturated monomers such as meth) acrylate and allyl glycidyl ether; (meth) acrylate having a polyoxyethylene chain whose molecular terminal is an alkoxy group; 2-acrylamido-2-methylpropanesulfonic acid, allylsulfonic acid , Sodium styrene sulfonate Polymerizable unsaturated monomers having a sulfonic acid group such as um salt, sulfoethyl methacrylate and its sodium salt, ammonium salt; 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxypropyl acid phosphate, Polymerizable unsaturated monomers having a phosphate group such as 2-methacryloyloxypropyl acid phosphate; 2-hydroxy-4- (3-methacryloyloxy-2-hydroxypropoxy) benzophenone, 2-hydroxy-4- (3-acryloyloxy) -2-hydroxypropoxy) benzophenone, 2,2′-dihydroxy-4- (3-methacryloyloxy-2-hydroxypropoxy) benzophenone, 2,2′-dihydroxy-4 Polymerizable unsaturated monomers having an ultraviolet-absorbing functional group such as (3-acryloyloxy-2-hydroxypropoxy) benzophenone, 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl) -2H-benzotriazole; 4 -(Meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-cyano-4- (meth) Acryloylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4 -Cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotono Luoxy-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6- UV-stable polymerizable unsaturated monomers such as tetramethylpiperidine; acrolein, diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate, formylstyrol, vinyl alkyl ketones having 4 to 7 carbon atoms (eg, vinylmethyl Examples thereof include polymerizable unsaturated monomer compounds having a carbonyl group such as ketone, vinyl ethyl ketone, and vinyl butyl ketone, and these can be used alone or in combination of two or more.

  The hydroxyl group-containing resin (A) is generally 30 to 300 mgKOH / g, particularly 40 to 250 mgKOH / g, more particularly 50 to 200 mgKOH / g, from the viewpoint of curability at low temperature and the water resistance of the resulting coating film. It preferably has a hydroxyl value within the range.

  The hydroxyl group-containing resin (A) may have an acid group such as a carboxyl group from the viewpoint of increasing the reactivity with the polyisocyanate compound (B). The hydroxyl group-containing resin (A) preferably has an acid value in the range of 0 to 20 mgKOH / g, particularly 0 to 15 mgKOH / g.

  The hydroxyl group-containing resin (A) generally has a weight average molecular weight in the range of 3,000 to 100,000, particularly 3,000 to 50,000, more preferably 4,000 to 30,000.

  Here, “weight average molecular weight” and “number average molecular weight” in the specification are based on the molecular weight of standard polystyrene from the chromatogram measured by gel permeation chromatography according to the method described in JIS K 0124-83. It is a calculated value. As the gel permeation chromatograph, “HLC8120GPC” (manufactured by Tosoh Corporation) was used. As the columns, four columns of “TSKgel G-4000HXL”, “TSKgel G-3000HXL”, “TSKgel G-2500HXL”, “TSKgel G-2000HXL” (both manufactured by Tosoh Corporation, trade name) were used, Mobile phase: Tetrahydrofuran, measurement temperature: 40 ° C., flow rate: 1 ml / min, detector: under the conditions of RI.

  The hydroxyl group-containing resin (A) preferably has a glass transition temperature of 0 ° C. or higher, particularly in the range of 5 ° C. to 80 ° C. from the viewpoints of coating film hardness and weather resistance.

  The glass transition temperature (° C.) here is a static glass transition temperature. For example, using a differential scanning calorimeter “DSC-50Q type” (manufactured by Shimadzu Corporation, trade name), a sample is taken into a measuring cup and vacuum suctioned. Then, after completely removing the solvent, after quenching in a nitrogen stream, the calorie change was measured in the range of −100 ° C. to 100 ° C. at a rate of temperature increase of 3 ° C./min. The change point was taken as the glass transition temperature.

Polyisocyanate compound (B):
The polyisocyanate compound (B) in the thermosetting two-component coating composition of the present invention is a compound having two or more free isocyanate groups in one molecule, and the isocyanate groups are not blocked with a blocking agent.

  Specifically, those conventionally used for polyurethane production can be used. Such polyisocyanates include aliphatic polyisocyanate compounds having 2 to 18 carbon atoms, alicyclic polyisocyanate compounds having 4 to 15 carbon atoms, araliphatic polyisocyanate compounds having 8 to 15 carbon atoms, carbon number (NCO 6-20 aromatic polyisocyanate compounds and crude products thereof, modified products of these polyisocyanate compounds (urethane group, carbodiimide group, allophanate group, urea group, burette group, uretdione) Groups, uretoimine groups, isocyanurate groups, oxazolidone group-containing modified products, etc.) and mixtures of two or more thereof.

  Specific examples of the aliphatic polyisocyanate compound include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate. Lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexano Eate.

  Specific examples of the alicyclic polyisocyanate compound include isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4′-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis ( 2-isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate, 2,5- and / or 2,6-norbornane diisocyanate.

  Specific examples of the araliphatic polyisocyanate compound include m- and / or p-xylylene diisocyanate (XDI), α, α, α ′, α′-tetramethylxylylene diisocyanate (TMXDI), and the like.

  Specific examples of the aromatic polyisocyanate compound include 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4 '-And / or 4,4'-biphenylmethane diisocyanate (MDI), 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl -4,4'-diisocyanatodiphenylmethane, crude MDI, 1,5-naphthylene diisocyanate, 4,4 ', 4 "-triphenylmethane triisocyanate, m- and p-isocyanatophenylsulfonyl isocyanate, etc. It is done.

  Examples of the modified polyisocyanate compound include modified MDI (urethane modified MDI, carbodiimide modified MDI, trihydrocarbyl phosphate modified MDI), urethane modified TDI, biuret modified HDI, isocyanurate modified HDI, isocyanurate modified IPDI and the like. Modified products of isocyanate; and mixtures of two or more thereof [for example, combined use of modified MDI and urethane-modified TDI (isocyanate group-containing prepolymer)]. Isocyanurate-modified HDI and the like are preferable.

  In addition to the polyisocyanate compound, those obtained by blocking isocyanate groups with a blocking agent can also be used. Examples of the blocking agent include phenol compounds; oxime compounds; lactam compounds; alcohol compounds; mercaptan compounds; pyrazole compounds; active methylene compounds such as diethyl malonate. When using a block polyisocyanate compound, it is preferable to use a dissociation catalyst for the blocking agent in combination. An unblocked polyisocyanate compound and a blocked polyisocyanate compound can also be used in combination.

  From the standpoint of corrosion resistance and weather resistance, preferred as the above polyisocyanate compounds are aliphatic polyisocyanate compounds and alicyclic polyisocyanate compounds. The number average molecular weight of the polyisocyanate compound is preferably 3,000 or less, particularly preferably in the range of 100 to 1,500.

  Commercially available products of such polyisocyanate compounds include Bayhydur TP-LS2550, Sumidur N3300 (above, manufactured by Sumika Bayer Urethane Co., Ltd.), TPA100 (manufactured by Asahi Kasei Chemicals Co., Ltd.), BASONAT (Basonate) HI100 (manufactured by BASF Corporation) and the like can be mentioned.

  The hydroxyl group-containing resin (A) is 60 to 90 parts by mass, preferably 65 to 85 parts by mass, and the polyisocyanate compound (B) per 100 parts by mass of the total solid content of the hydroxyl group-containing resin (A) and the polyisocyanate compound (B). A range of 10 to 40 parts by mass, preferably 15 to 35 parts by mass is preferable from the viewpoint of coating stability and curability.

Barium sulfate (C) having an average particle size of 1.0 to 15 μm:
By containing barium sulfate (C) having an average particle size of 1.0 to 15 μm or more, the coating composition of the present invention can obtain a stable matte coating film in combination with silica fine particles (D) described later. it can. As such a commercial product of barium sulfate (C), barium sulfate BA (trade name, manufactured by Sakai Chemical Co., Ltd., barium sulfate powder), LAKABAR SF (LAKAVISUTH), barium sulfate powder, average particle diameter: 10.4 μm), SPARWITE (Spurwite) W-5HB (trade name, manufactured by Wilber Ellis, barium sulfate powder, average particle size: 1.6 μm).

  In addition, in this specification, an average particle diameter is a value obtained by the particle size distribution measurement by a dynamic light scattering method, and more specifically, a value measured using UPA-EX250 (trade name, manufactured by Nikkiso Co., Ltd.). Means.

  The blending amount of barium sulfate (C) is determined based on the total solid content of 100 parts by mass of the hydroxyl group-containing resin (A) and the polyisocyanate compound (B) in order to obtain a stable matte coating film. 1 to 150 parts by mass, preferably 2 to 100 parts by mass, and more preferably 3 to 50 parts by mass.

Silica fine particles (D):
Silica fine particles (D) are, for example, Aerosil 200, Aerosil 300, Aerosil 380, Aerosil TT600 (above, manufactured by Nippon Aerosil Co., Ltd.), Syloid 74, Syloid 83, Syloid 161, Syloid 162, Syloid 244, Syloid 308, Syloid. 378 (above, manufactured by Fuji Devison Chemical Co., Ltd.), Mizukacil P-526, Mizukacil P-527, Mizukacil P-801, Mizukacil NP-8 (above, produced by Mizusawa Chemical Co., Ltd.), Nip Seal E200A, Nip Seal E220 ( As described above, manufactured by Nippon Silica Kogyo Co., Ltd.), Fine Seal E-50, Fine Seal E-70, Fine Seal T-32, Fine Seal X-37 (above, manufactured by Tokuyama Soda Co., Ltd.), Carplex # 67, Carplex # 80 (above, Shio Formic Pharmaceutical Co., Ltd.), and the like.

Also, ion-exchanged amorphous silica fine particles can be used. The ion-exchanged amorphous silica fine particles are silica fine particles in which alkaline earth metal ions such as calcium ions and magnesium ions are introduced into a fine porous silica carrier by ion exchange. Among the alkaline earth metal ions, calcium ions are preferred. The ion-exchanged amorphous silica fine particles blended in the coating film are ion-exchanged with hydrogen ions and oxygen ions that have permeated through the coating film, and alkali such as calcium ion (Ca ²⁺ ) or magnesium ion (Mg ²⁺ ). It is thought that earth metal ions are released to protect the metal surface. Examples of commercially available calcium ion-exchanged silica include, for example, SHIELDEX (registered trademark) C303, SHIELDEX AC-3, SHIELDEX AC-5 (all of which are manufactured by WR Grace & Co.). And the like.

  For the purpose of obtaining a stable matte coating film, the content of such silica fine particles (D) is preferably such that it does not impair the finish, and the hydroxyl group-containing resin (A) and the polyisocyanate compound ( The range of 0.1 to 30 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 1 to 8 parts by mass based on 100 parts by mass of the total solid content of B). The average particle diameter of such silica fine particles (D) is, for example, 0.1 to 30 μm, preferably 0.1 to 15 μm.

  In addition, the mixing ratio of barium sulfate (C) and silica fine particles (D) is used such that the mass ratio of barium sulfate (C) / silica fine particles (D) is in the range of 1 to 30, preferably 2 to 20. It is also preferable to obtain a stable matte coating film.

Rheology control agent (E):
The addition of the rheology control agent (E) stabilizes the matte degree of the entire coating film by controlling the ups and downs and the vertical and horizontal flow of barium sulfate (C) and silica fine particles (D) in the coating film. Objective. Specifically, by adjusting the viscosity of the wet coating film from atomization during coating to coating and drying, the flow of barium sulfate (C) and silica fine particles (D) during coating film formation is controlled, and gloss Gives properties to stabilize the decoating film.

  The chemical structure is not particularly limited as long as it exhibits such characteristics. For example, acrylic (including a structure composed of a polymer or oligomer of an acrylate ester or methacrylic ester in the molecule), a polyolefin (eg polyethylene, polypropylene, etc.) , Amides (higher fatty acid amides, polyamides, oligomers, etc.), anionic surfactants (sulfuric ester surfactants, anionic fatty acid surfactants, linear alkylbenzene surfactants, higher alcohol surfactants, alpha Olefin surfactants, normal paraffin surfactants, etc.), nonionic surfactants (nonionic fatty acid surfactants, higher alcohol surfactants, alkylphenol surfactants, etc.), polycarboxylic acids (in the molecule) At least two or more carboxyl groups Containing derivatives), cellulose (including various derivatives such as nitrocellulose, acetylcellulose, and cellulose ether), urethane (polymers containing a urethane structure in the molecule, oligomers, etc.), urea (polymers containing a urea structure in the molecule) , Oligomers, etc.), urethane urea (polymers containing a urethane structure and a urea structure in the molecule, oligomers, etc.), or one or more compounds selected from the group.

  In addition, the rheology control agent (E) may be in a solid state or a liquid state at normal temperature, but is more preferably a liquid from the viewpoint that it can be easily added in the production process. However, even a solid state at ordinary temperature can be used by dissolving or dispersing in a suitable solvent.

  Commercially available products as the rheology control agent (E) include, for example, amide wax such as Disparon 6900 (manufactured by Enomoto Kasei Co., Ltd.), Chixol W300 (Kyoeisha Chemical Co., Ltd.); Disparon 4200 (manufactured by Enomoto Kasei Co., Ltd.), etc. Polyethylene wax; Cellulose rheology control agents such as CAB (cellulose acetate butyrate, Eastman Chemical Products), HEC (hydroxyethylcellulose), hydrophobized HEC, CMC (carboxymethylcellulose); BYK-410, BYK -411, BYK-420, BYK-425 (above, manufactured by BYK Chemie Co., Ltd.) and other urethane urea-based rheology control agents; sulfate nonionic surface actives such as Flownon SDR-80 (Kyoeisha Chemical Co., Ltd.) Agent; Non SA-345HF (manufactured by Kyoeisha Chemical Co.) rheology control agents polyolefin such as; Furonon HR-4AF (Kyoeisha Chemical Co.) rheology control agent of higher fatty acid amide-based and the like; and the like.

  In particular, the urethane urea-based rheology control agent (E) is preferable for obtaining a characteristic that stabilizes the matte level because an optimum viscosity is obtained at the time of setting or baking and drying.

  The rheology control agent (E) is added in an amount of 0 based on the total solid content of the hydroxyl group-containing resin (A) and the polyisocyanate compound (B) in order to obtain a stable matte coating film. .1 to 20 parts by mass, preferably 0.3 to 15 parts by mass, and more preferably 0.5 to 10 parts by mass.

Polyether polyol (F):
In the thermosetting two-component coating composition of the present invention, a polyether polyol (F) can be used as necessary in addition to the hydroxyl group-containing resin (A). That is, the thermosetting two-component coating composition of the present invention may contain a polyether polyol (F).

Such polyether polyol (F) is, for example, represented by the following formula (1):
R ¹ — (R ² _n —OH) _m Formula (1)
(In the formula (1), m is an integer of 2 to 9, R ¹ is an m-valent organic group, R ² is a divalent organic group, and m n are each independently 1 to 5 Is an integer.)
The polyether polyol represented by these can be mentioned.

M in the above formula (1) is preferably an integer of 3 to 6, more preferably 3 or 4, and further preferably 3. n is preferably 1. Preferred examples of R ¹ may be mentioned as preferred examples of R ¹ in the formula (1), a group obtained by removing four hydroxyl groups from groups or tetra alcohol excluding the three hydroxyl groups from birds alcohol. Examples of the trialcohol include glycerin, trimethylolpropane, 1,2,3-butanetriol, 1,2,4-butanetriol, and the like. Examples of tetraalcohol include pentaerythritol and ditrimethylolpropane. As a preferable example of R ^2, the following formula —O—R ³ —
(In the formula, R ³ is an alkylene group.)
The divalent group represented by these can be mentioned.

Preferable examples of R ³ in the above formula include, for example, ethylene group, 1,2-propylene group, trimethylene group and the like.

  Examples of such commercially available polyether polyols (F) include Sannics GP-600, Sannics GP-1000, Exenol 430, Exenol 385SO, Exenol 450ED, Exenol 500ED, Exenol 750ED (above, manufactured by Asahi Glass Co., Ltd.), Examples include ADEKA polyether (manufactured by ADEKA Corporation), Actol T-100 (manufactured by Mitsui Polyurethane Co., Ltd.), and the like. The number average molecular weight of such polyether polyol (F) is less than 3,000, preferably 90 to 2,000, more preferably 500 to 1,500.

  Since the content of the polyether polyol (F) in the thermosetting two-component coating composition can provide a finished film, a stable matte coating film, water resistance, and corrosion resistance, a hydroxyl group-containing resin. 0.1 to 30 parts by weight, preferably 1 to 20 parts by weight, more preferably 3 to 15 parts by weight, more preferably, based on 100 parts by weight of the total solid content of (A) and the polyisocyanate compound (B). 5 to 10 parts by mass is suitable.

  In the thermosetting two-component coating composition of the present invention, for example, coloring pigments such as titanium oxide, carbon black, and bengara; extender pigments such as clay, talc, mica, and calcium carbonate; Antirust pigments such as bismuth, basic bismuth carbonate, bismuth nitrate and bismuth silicate; polyamine compounds, UV absorbers, antifoaming agents, pigment dispersants, surface conditioners, surfactants, curing catalysts, thickeners, antiseptics An agent, an antifreezing agent and the like can be blended.

In addition, the coating method using the thermosetting two-component coating composition of the present invention can obtain a coating film by, for example, the following steps 1 to 3:
Step 1: Apply degreasing, surface adjustment, chemical conversion treatment, etc. to the object to be coated, if necessary.
Step 2: Next, if necessary, an undercoat paint such as an electrodeposition paint or a primer paint is applied to form a coating film.
Step 3: Further, a thermosetting two-component coating composition is applied to, for example, dip coating, brush coating, roll brush coating, spray coating, roll coating, spin coating, dip coating, bar coating, flow coating, electrostatic coating, Using a coating method such as electrodeposition coating or die coating, a dry film thickness of 10 μm to 150 μm, preferably 30 μm to 100 μm, is applied and cured at room temperature to 160 ° C. for 10 to 120 minutes, preferably 60 to 120 ° C. for 20 to 90 minutes. By doing so, a coated article can be obtained. For example, the present invention includes a step of applying the thermosetting two-component coating composition to the article to be coated without applying the primer coating, or the thermosetting two-component coating composition. There is provided a method for coating an object to be coated, comprising a step of baking and drying the object to be coated at 50 to 170 ° C. for 10 to 120 minutes. The obtained coated article can obtain a matte coating film having a 60-degree specular gloss of 10 to 70, preferably 55 to 65, and there is little variation in gloss due to baking temperature.

Examples of the article to be coated include cold rolled steel sheet, black leather sheet, alloyed galvanized steel sheet, electrogalvanized steel sheet, and aluminum. Further, if necessary, shot blasting, surface adjustment, chemical conversion treatment and the like can be performed. Moreover, the low temperature curing (50-100 degreeC) of the said description is suitable for the components whose coating material has a large heat capacity and cannot fully heat a coating film.

  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 each example, “parts” indicates mass parts, and “%” indicates mass%.

Production Example 1 Acrylic resin no. Production of 1 solution 28 parts of SWAZOL 1000 (manufactured by Cosmo Oil Co., Ltd., aromatic hydrocarbon solvent), 85 parts of toluene, 41.6 parts of styrene, 6.9 parts of n-butyl acrylate, 19 parts of isobutyl methacrylate, Plaxel FM- 3 (Note 1) 15 parts, 17 parts of 2-hydroxyethyl methacrylate, 0.5 parts of acrylic acid and 8 parts of di-tert-butyl hydroperoxide were reacted at 110 ° C. under nitrogen gas to give an acid value of 3.9 mgKOH / g, a hydroxyl value of 94.9 mgKOH / g, and an acrylic resin No. 1 having a weight average molecular weight of 11,000. Got one:
(Note 1) Plaxel FM-3: Daicel Chemical Industries, Ltd., trade name, ε-caprolactone-modified vinyl monomer of 2-hydroxyethyl acrylate.

Production Examples 2 to 4 Acrylic resin no. 2-No. 4
Acrylic resin No. 1 was prepared in the same manner as in Production Example 1 except that the monomer mixture having the composition shown in Table 1 was used. 2-No. 4 was obtained.

Production Example 5 Pigment Dispersion Paste No. Production Example 1 Acrylic resin No. 60% solid content obtained in Production Example 1 100 parts (solid content 60 parts), Monarch 1300 (Note 2) 5 parts, LAKABAR SF (Note 3) 100 parts, Mizukasil P-526 (Note 8) 10 parts, and Swazol 1000 (Cosmo Oil Co., Ltd.) Manufactured by an aromatic hydrocarbon solvent), charged in a ball mill and stirred for 6 hours. 1 was obtained.

Production Examples 6 to 15 Pigment dispersion paste No. 2-No. 11 Production Example Pigment-dispersed paste No. 11 was prepared in the same manner as in Production Example 5 except that the contents shown in Table 2 were used. 2-No. 11 was obtained.

(Note 2) Monarch 1300: Product name, carbon black, manufactured by Cabot Corporation (Note 3) Product name, barium sulfate powder, average particle size 10.4 μm, LAKABAR (SF)
(Note 4) Barium sulfate BA: manufactured by Sakai Chemical Industry Co., Ltd., trade name, barium sulfate, average particle size 6 μm
(Note 5) SPARWITE (Spurwite) W-5HB: Product name, barium sulfate powder, average particle size 1.6 μm, manufactured by Wilber Ellis
(Note 6) Varifine BF-20: manufactured by Sakai Chemical Industry Co., Ltd., trade name, barium sulfate having an average particle size of 0.03 μm (Note 7) BARIACE B-30: manufactured by Sakai Chemical Industry Co., Ltd., trade name, average particle size of 0 .3 μm barium sulfate (Note 8) Mizukacil P-526: Mizusawa Chemical Co., Ltd., trade name, silica, average particle size 3.2 μm.

Manufacture of paint compositions
Example 1 Coating composition no. 1
Acrylic resin No. 1 obtained in Production Example 1. No. 1 19 parts (solid content), Sumidur N3300 (Note 9) 21 parts (solid content), and pigment dispersion paste No. 1 obtained in Production Example 5. 1 was blended with 175 parts (solid content) and 0.8 part of BYK-410 (Note 10), adjusted to a solid content of 60% by mass. 1 was obtained.

Examples 2 to 14 Coating composition No. 2-No. 14
A coating composition No. having a solid content of 60% by mass was prepared in the same manner as in Example 1 except that the blending contents shown in Table 3 were used. 2-No. 14 was obtained. The results obtained for the test according to the following “Production of test plate” are also shown.

(Note 9) Sumidur N3300: manufactured by Sumika Bayer Urethane Co., Ltd., trade name, hexamethylene diisocyanate isocyanurate, NCO equivalent 193
(Note 10) BASONAT HI100: manufactured by BASF, trade name, isocyanurate of hexamethylene diisocyanate, NCO equivalent 190
(Note 11) BYK-410: manufactured by BYK Chemie Corp., trade name, urethane urea rheology control agent (Note 12) BYK-425: manufactured by BYK Chemie Corp., trade name, urethane urea rheology control agent (Note) 13) Flownon SA-345HF: manufactured by Kyoeisha Chemical Co., Ltd., trade name, polyolefin rheology control agent (Note 14) Actol T-1000: manufactured by Mitsui Takeda Chemical Co., trade name, polyether polyol, number average molecular weight 1 , 000
(Note 15) Exenol 750ED: Asahi Glass Co., Ltd., trade name, polyether polyol, number average molecular weight 750

Comparative Examples 1-10 Coating Composition No. 15-No. 24
A coating composition No. having a solid content of 60% by mass was prepared in the same manner as in Example 1 except that the blending contents shown in Table 4 were used. 15-No. 24 was obtained. The results obtained for the test according to the following “Production of test plate” are also shown.

Preparation of test plates and performance evaluation Cold-coated steel sheets (70 mm x 300 mm x 2.0 mm) that have been subjected to zinc phosphate treatment and chemical conversion treatment are electrodeposited to a dry film thickness of 20 µm, baked and dried for electrodeposition A coated plate was obtained. Subsequently, coating composition No. obtained in said Examples 1-14 and Comparative Examples 1-10. 1-No. 24 was spray-coated so as to have a dry film thickness of 50 μm. Next, each test plate was obtained by heating and drying according to each test item using an electric hot air dryer.

Performance evaluation (Note 16) Paint stability:
Each paint composition was placed in a 250 ml glass container and stored in the dark at 20 ° C. for 4 hours to check the condition:
◎: No sedimentation of the coating composition is observed. ○: Sedimentation of the coating composition is slightly recognized, but returns to the original state even with gentle stirring. △: Slightly at least one of gelation and phase separation of the coating composition. Seen in
In x, at least one of gelation and phase separation of the coating composition is significantly observed.

(Note 17) Finishing property: The appearance of the coated plate was visually evaluated on a test plate that had been heat-dried at 95 ° C. for 20 minutes:
○ indicates smoothness and no problem. △ indicates a slight decrease in finish such as swell, gloss, and chilli skin.
X indicates a large decrease in finish such as swell, gloss, and chile skin.

  (Note 18) Pencil hardness: A test plate heated and dried at 95 ° C. for 20 minutes is applied with a pencil lead at an angle of about 45 ° with respect to the test coating plate surface in accordance with JIS K 5600-5-4. It was moved about 10 mm forward at a uniform speed while pressing firmly against the test coating surface to the extent that it could not be broken. The hardness symbol of the hardest pencil that did not tear the coating film was defined as pencil hardness.

(Note 19) Stability of matte paint film: Cold-rolled steel sheet (70 mm x 300 mm x 2.0 mm) that has been subjected to zinc phosphate treatment and chemical conversion treatment is electrodeposited to a dry film thickness of 20 µm and baked. Dryed to obtain an electrodeposited coating plate:
Subsequently, the coating composition Nos. Obtained in the above Examples 1 to 14 and Comparative Examples 1 to 10. 1-No. 24 was spray-coated “vertically” to a dry film thickness of 50 μm and dried by heating (60 ° C. for 20 minutes, 95 ° C. for 20 minutes, 160 ° C. for 20 minutes). The glossiness of each coating film was determined according to JIS K 5600-4-7 (1999) “60 degree specular glossiness”, and the reflectance when the incident angle and the light receiving angle were 60 degrees respectively, An “average value” was determined by measuring n = 10 at intervals of about 2.5 cm in the direction. Further, “glossiness variation” was evaluated according to the following criteria at n = 10. Also, the glossiness of the coated plate baked at 60 ° C. for 20 minutes and the “gloss difference (Δ)” of the coated plate baked at 160 ° C. for 20 minutes were determined:
◎: The range of maximum and minimum glossiness is within ± 2,
◯ indicates that the range of maximum and minimum glossiness exceeds 2 and within 5;
△ is within 10 with the range of maximum and minimum glossiness exceeding 5;
In x, the range of the maximum value and the minimum value of glossiness exceeds 10.

(Note 20) Water resistance: Using a test plate heated and dried at 95 ° C. for 20 minutes, immersed in deionized water at 40 ° C. for 240 hours, in accordance with JIS K 5600-5-6 (1999) grid pattern-tape method, Using a knife so that the coating surface of the paint plate reaches the base, 11 cuts are made in parallel in the vertical and horizontal directions at intervals of about 2 mm to form a goby, and cellophane (registered trademark) adhesive is applied to the surface. The applied surface after applying the tape and abruptly peeling the tape was evaluated according to the following criteria:
◎: No peeling of the coating film is observed. ○: A slight peeling is observed in a part of the coating film on the knife scratch. X indicates that 21 or more of the 100 gobangs are peeled off.

(Note 21) Anticorrosion: Using a test plate heated and dried at 95 ° C. for 20 minutes, a cut cut was made with a knife, and this was subjected to a salt spray resistance test for 120 hours according to JIS Z-2371. According to the width of the bulge, the following criteria were used:
◎ indicates that the maximum width of rust and blisters is less than 2 mm (one side) from the cut,
○, the maximum width of rust and blisters is 2mm or more and less than 3mm (one side) from the cut part,
△ indicates that the maximum width of rust and blisters is 3 mm or more and less than 4 mm (one side) from the cut part,
X: The maximum width of rust and blisters is 4 mm or more from the cut part (one side).

(Note 22) Weather resistance: Using a test plate heat-dried at 95 ° C. for 20 minutes, in the sunshine carbon arc lamp type light resistance and weather resistance test stipulated in JIS B-7533, the irradiation time is a maximum of 1,200 hours. The test was conducted up to. In the coating on the test plate, the irradiation time was measured at which the gloss retention with respect to the gloss before the test was 80%:
◯ indicates that the gloss retention is 80% or more even when the irradiation time is 1,200 hours. Δ indicates that the irradiation time when the gloss retention is less than 80% is 1,000 hours or more and less than 1200 hours.
X: The irradiation time when the gloss retention is less than 80% is less than 1,000 hours.

(Note 23) Comprehensive evaluation: In the field of the thermosetting two-component coating composition to which the present invention belongs, low temperature curability, finish, coating film hardness, matte coating stability, water resistance, anticorrosion and It is desirable that all of the weather resistance is excellent. Therefore, a comprehensive evaluation was performed based on the following criteria:
◎, Finishing property, Pencil hardness, Glossiness variation of matte coating (dried at 60 ° C for 20 minutes), Glossiness variation of matting coating (95 ° C for 20 minutes), Glossiness of matte coating Variation (drying at 160 ° C. for 20 minutes), water resistance, corrosion resistance, and weather resistance are all ◎ or ○, 6 or more of these 8 items are ◎, pencil hardness is HB or higher, matte The glossiness (average value) of the coating film is 50 to 65 in all coating films at 60 ° C. for 20 minutes, 95 ° C. for 20 minutes and 160 ° C. for 20 minutes, and the gloss difference is 5 or less.
○ Finishability, pencil hardness, glossy coating gloss variation (60 ° C, 20 minutes drying), matting coating glossiness variation (95 ° C, 20 minutes drying), matting coating glossiness variation (Drying at 160 ° C. for 20 minutes), water resistance, corrosion resistance, and weather resistance are all ◎ or ○, and among these 8 items, ◎ is 5 or less, pencil hardness is HB or harder, matte coating The glossiness (average value) of the film is 50 to 65 in all coating films at 60 ° C for 20 minutes, 95 ° C for 20 minutes and 160 ° C for 20 minutes, and the gloss difference is 5 or less.
△ Finishability, pencil hardness, glossiness coating gloss variation (60 ° C, 20 minutes drying), matting coating glossiness variation (95 ° C, 20 minutes drying), matting coating glossiness variation (Drying at 160 ° C. for 20 minutes), water resistance, corrosion resistance, and weather resistance are all ◎, ○ or Δ, at least 1 is △, pencil hardness is HB or harder, glossiness of matte coating film (Average value) is 50 to 65 in all coating films of 60 ° C. for 20 minutes, 95 ° C. for 20 minutes and 160 ° C. for 20 minutes, and the gloss difference is 5 or less.
× Finishability, pencil hardness, glossy coating variability (drying at 60 ° C for 20 minutes), matting coating glossiness variation (95 ° C for 20 minutes drying), matting coating glossiness variation (Dry at 160 ° C. for 20 minutes) At least one of water resistance, corrosion resistance, and weather resistance is x, pencil hardness is B or softer, or gloss (average value) of matte coating is 60 At least one of the coating films of 20 ° C. drying for 20 minutes, 95 ° C. for 20 minutes and 160 ° C. for 20 minutes is less than 50 or more than 65, and the gloss difference is 6 or more.

  A coated article having excellent low-temperature curability, finish, coating film hardness, matte coating stability, water resistance, corrosion resistance, and weather resistance can be provided.

Claims (8)

A composition containing a hydroxyl group-containing resin (A), a polyisocyanate compound (B), barium sulfate (C) having an average particle size of 1.0 to 15 μm, silica fine particles (D), and a rheology control agent (E). ,
A ratio of 60 to 90 parts by mass of the hydroxyl group-containing resin (A) and 10 to 40 parts by mass of the polyisocyanate compound (B) based on 100 parts by mass of the total solid content of the hydroxyl group-containing resin (A) and the polyisocyanate compound (B). And 2 thermosetting liquids containing 1 to 150 parts by mass of barium sulfate (C), 0.1 to 30 parts by mass of silica fine particles (D), and 0.1 to 20 parts by mass of rheology control agent (E). Mold paint composition. The thermosetting of Claim 1 containing 0.1-30 mass parts of polyether polyols (F) on the basis of 100 mass parts of total solid content of a hydroxyl-containing resin (A) and a polyisocyanate compound (B). Two-component paint composition. The thermosetting two-component coating composition according to claim 1 or 2, wherein the rheology control agent (E) is a urethane urea rheology control agent. The thermosetting two-component coating composition according to any one of claims 1 to 3, wherein the hydroxyl group-containing resin (A) is a hydroxyl group-containing acrylic resin. The thermosetting two-component paint composition according to any one of claims 1 to 4, which is a paint for construction machinery or industrial machinery. A step of applying the thermosetting two-component coating composition according to any one of claims 1 to 5 without applying a primer coating to the article to be coated, or the thermosetting 2 A method for coating an object to be coated, comprising a step of baking and drying an object coated with a liquid coating composition at 50 to 170 ° C. for 10 to 120 minutes. A coated article having a coating film obtained by the coating method according to claim 6, wherein the coated film has a 60-degree specular gloss of 10 to 70. The coated article according to claim 7, wherein the article to be coated is a construction machine or an industrial machine.