Coating composition and coating film

Abstract

To provide a coating composition which is suppressed in viscosity increase even in a coating material having a high solid content concentration of 70 wt.% or more and has excellent matte appearance and good chemical resistance when formed into a coating film.SOLUTION: There is provided a coating composition which comprises an aspartic acid ester compound and / or a hydroxyl group-containing resin compound and wax particles, wherein the content of the wax particles having an average particle diameter of 10 to 100 μm is 10 to 200 wt.% based on the total amount of the aspartic acid ester compound and / or the hydroxyl group-containing resin compound.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a coating composition and a coating film. [Background technology]

[0002] In recent years, with the times such as the SDGs, companies are being asked to take environmentally friendly actions, and various efforts are being made in the fields of coating materials and paints. One example is technology that reduces the amount of volatile organic solvents (VOCs) emitted during the coating film curing / drying process by increasing the solids concentration of the paint, thereby reducing the environmental impact. In addition to reducing the environmental impact, there is also a demand to not impair or even improve the strength and durability of the resulting coating.

[0003] Aspartic acid ester compounds have a lower viscosity than polyol, the main component of polyurethane coating compositions, when used alone, and can significantly reduce the amount of dilution solvent in the polyaspartic coating composition, making it possible to prepare high-solids or solvent-free formulations.

[0004] In addition, due to the fast reactivity between the amino groups of the aspartic acid ester compound and the isocyanate groups of the aliphatic and / or alicyclic polyisocyanate, polyaspartic paint compositions have the advantages of a faster curing rate even at room temperature and superior mechanical strength compared to polyurethane paint compositions, and are therefore expected to have many applications.

[0005] For example, Patent Document 1 discloses a polyaspartic paint composition containing a polyaspartic acid ester compound and a polyisocyanate composition in which the contents (mol %) of isocyanurate groups, iminooxadiazinedione groups, uretdione groups, allophanate groups, and biuret groups are in a specified relationship. In this polyaspartic paint composition, the polyisocyanate composition has a low viscosity suitable for high solid formulations and solventless formulations, and while maintaining curability and drying properties, the coating film using this polyaspartic paint composition has the advantage of being excellent in chemical resistance, hardness, and weather resistance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2018 / 163953 Summary of the Invention [Problem to be solved by the invention]

[0007] However, although the polyaspartic coating composition proposed in Patent Document 1 achieves high solidity, there is no mention of a method for obtaining a matte appearance that would enable use in the exterior field.

[0008] Silica (silicon dioxide) is generally used as a matting agent in paints. When paints containing silica are diluted with a solvent, the hydrogen bonds between the silica particles weaken, and the viscosity can be controlled to a range suitable for coating. On the other hand, in high-solids and solvent-free paints, the solvent content is low, so the silica content is relatively high and the hydrogen bonds between the silica particles are strong, resulting in problems such as high viscosity paints that are not suitable for coating and poor coating appearance. The appropriate range of coating viscosity varies depending on the performance of various coating machines, but for paints containing matting agents such as silica, the appropriate viscosity range during coating is said to be a maximum of 20,000 mPa·s or less in terms of coatability and coating appearance, but as the silica content increases, it becomes more difficult to control. Furthermore, silica has poor chemical resistance, particularly alkali resistance, and it was known that when a coating film containing a large amount of silica is used under strongly alkaline conditions, the coating film becomes cloudy and suffers from poor appearance such as blistering and peeling, as well as deterioration over time such as poor weather resistance.

[0009] The present invention has been made in view of the above circumstances, and provides a coating composition that suppresses viscosity increase even in a coating having a high solid content concentration of 70% by weight or more, has an excellent matte appearance, and when formed into a coating film, has good chemical resistance. [Means for solving the problem]

[0010] That is, the present invention includes the following aspects. (1) An aspartic acid ester compound (A-1) and / or a hydroxyl group-containing resin compound (A-2), and wax particles (B), the wax particles (B) have an average particle size of 10 μm or more and 100 μm or less, and a content of 10% by weight or more and 200% by weight or less based on the total amount of the aspartic acid ester compound (A-1) and / or the hydroxyl group-containing resin compound (A-2); A paint base agent with a solids concentration of 70% by weight or more. (2) The base material for a coating material according to (1), wherein the wax particles (B) are particles containing at least one wax selected from the group consisting of polyolefin wax, paraffin wax, microcrystalline wax, and aliphatic wax. (3) A coating composition comprising the base coating material according to (1) or (2) and a polyisocyanate composition (C), and having a solids concentration of 70% by weight or more. (4) A coating film obtained by curing the coating composition described in (3). (5) A composition comprising a polyisocyanate composition (C) and wax particles (B), The wax particles (B) have an average particle size of 10 μm or more and 100 μm or less, and a content of 10% by weight or more and 200% by weight or less based on the total amount of the polyisocyanate composition (C), A paint hardener with a solids concentration of 70% by weight or more. Effect of the Invention

[0011] According to the coating composition of the above embodiment, it is possible to provide a coating composition that suppresses an increase in viscosity even in a coating having a high solid content concentration of 70% by weight or more, and has an excellent matte appearance. In addition, when the coating composition is used to form a coating film, the chemical resistance is good. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment for carrying out the present invention (hereinafter, referred to as "the present embodiment") will be described in detail. Note that the present invention is not limited to the following embodiment. The present invention can be carried out with appropriate modifications within the scope of the gist of the present invention.

[0013] <Wax particles (B)> The wax particles (B) of this embodiment have an average particle size of 10 μm or more and 100 μm or less. The average particle size is preferably 10 μm or more and 90 μm or less, more preferably 15 μm or more and 70 μm or less, and even more preferably 40 μm or more and 60 μm or less. When the average particle size is within the above range, the wax particles unevenly distributed on the coating film surface give the coating film surface an appropriate surface roughness, thereby obtaining excellent matte properties.

[0014] The content of the wax particles (B) is 10% by weight or more and 200% by weight or less based on the total amount of the aspartic acid ester compound (A-1) and / or the hydroxyl group-containing resin compound (A-2). The content is more preferably 15% by weight or more and 150% by weight or less, and more preferably 25% by weight or more and 130% by weight or less. When the content is within the above range, the viscosity of the obtained coating material and the matte property of the coating film can be compatible within an appropriate range.

[0015] The wax particles (B) are, for example, particles containing at least one selected from the group consisting of polyolefin wax, paraffin wax, microcrystalline wax, and aliphatic wax. Among them, polyolefin wax is preferred. By using the wax particles, the wax particles with high hydrophobicity are unevenly distributed on the coating film surface during the coating film formation process. This allows the coating film to have a better matte property than when a normal matte agent is used.

[0016] As the polyolefin wax, for example, polyethylene wax, modified polyethylene wax, amide modified polyethylene wax, PTFE modified polyethylene wax, polypropylene wax, modified polypropylene wax, etc. can be used.

[0017] Specific examples of the wax particles (B) include, but are not limited to, CERAFLOUR913, CERAFLOUR914, CERAFLOUR915, CERAFLOUR916, CERAFLOUR917, CERAFLOUR925, CERAFLOUR927, CERAFLOUR929, CERAFLOUR950, CERAFLOUR970, CERAFLOUR981R, CERAFLOUR988, CERAFLOUR991, CERAFLOUR994, CERAFLOUR996R, and CERAFLOUR997R manufactured by BYK-Chemie. , CERAFLOUR998R, CERAFLOUR1000, MP Gokyo Food & Chemical Co., Ltd.'s PropylTex100S, PropylTex140S, PropylTex200S, PropylTex200SF, PropylTex230S, PropylTex270S, PropylTex325S, Sanyo Kasei Co., Ltd.'s Viscol 330-P, Viscol 440-P, Viscol 550-P, Viscol 660-P, Sunwax 161-P, Sunwax 131-P, Sunwax 151-P, Sunwax 171-P, Shamrock Examples of such copolymers include S-379H, S-379N8, S-394MG, S-394N1, S-394N5, S-395N2, S-395N5, S-395SP5, and S-363 manufactured by Technologies.

[0018] The coating composition using the wax particles (B) of this embodiment, or the base agent for coating or the curing agent for coating used in the coating composition, can achieve both excellent matte appearance and suppression of viscosity increase of the coating, which is usually difficult at a high solid content concentration of 70% by weight or more. In addition, the coating composition has good appearance and chemical resistance when formed into a coating film.

[0019] Next, each of the components contained in the coating composition of the present embodiment will be described in detail below.

[0020] <Aspartic acid ester compound (A-1)> The aspartic acid ester compound (A-1) used in this embodiment is an aspartic acid ester compound represented by the following formula (I).

[0021] [ka]

[0022] [In formula (I), X is an n-valent organic group obtained by removing a primary amino group of an n-valent polyamine, R 1 and R 2 are the same or different organic groups that are inert to isocyanate groups under reaction conditions, and n is an integer of 2 or more.

[0023] (X) In the general formula (I), X is an n-valent organic group.

[0024] The n-valent organic group may be an aliphatic group or an aromatic group. The aliphatic group may be linear, branched, or cyclic. In addition, n is an integer of 2 or more, as described later.

[0025] Examples of the linear or branched aliphatic group include an alkanediyl group (alkylene group), an alkylidene group, and an alkylidyne group. Examples of the cyclic aliphatic group include a cycloalkylene group. The aromatic group may, for example, be an arylene group such as a phenylene group.

[0026] More specifically, from the viewpoint of the yellowing resistance of the polyaspartic coating composition of this embodiment, X is preferably a linear, branched or cyclic divalent aliphatic group having from 2 to 20 carbon atoms. Examples of the linear, branched or cyclic divalent aliphatic group having from 2 to 20 carbon atoms include an n-butylene group, an n-pentylene group, an n-hexylene group, a 2,2,4-trimethylhexamethylene group, a 2,4,4-trimethylhexamethylene group, a 3,3,5-trimethyl-5-methylcyclohexylene group, a dicyclohexylmethylene group, and a 3,3'-dimethyldicyclohexylmethylene group.

[0027] (R 1 and R 2 ) In the general formula (I), R 1 and R 2 are each independently an organic group that is inert to isocyanate groups under reaction conditions. In this specification, the term "inert to isocyanate groups under reaction conditions" means that R 1 and R 2 does not have any Zerewitinoff active hydrogen-containing groups (CH acidic compounds) such as hydroxyl, amino, or thiol groups.

[0028] R 1 and R 2 are each independently preferably an alkyl group having 1 to 10 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, or a butyl group.

[0029] R 1 and R 2 may be the same or different.

[0030] (n) In general formula (I), n is an integer of 2 or more. Among these, n is preferably an integer of 2 or more and 6 or less, more preferably an integer of 2 or more and 4 or less, even more preferably 2 or 3, and particularly preferably 2.

[0031] <Method for producing an aspartic acid ester compound represented by formula (I)> The aspartic acid ester compound represented by formula (I) can be produced by the method described in WO 2018 / 163959.

[0032] <Hydroxyl group-containing resin compound (A-2)> The hydroxyl-containing resin compound (A-2) used in this embodiment may be polyester polyol, polyether polyol, acrylic polyol, polyolefin polyol, fluorine polyol, polycarbonate polyol, polyurethane polyol, etc. These hydroxyl-containing resin compounds may be contained alone or in combination of two or more. Among them, acrylic polyol or polyester polyol is preferred as the hydroxyl-containing resin compound.

[0033] <Isocyanate group / Amino group> The molar ratio (isocyanate group / amino group) of the isocyanate group of the polyisocyanate composition (C) to the amino group of the aspartic acid ester compound (A-1) is preferably 1 / 10 or more and 10 / 1 or less, more preferably 1 / 5 or more and 5 / 1 or less, and even more preferably 1 / 2 or more and 2 / 1 or less. When the isocyanate group / amino group is 1 / 10 or more, the main agent does not become too excessive, and the elongation at a low temperature of about -20 ° C. when formed into a coating film can be made good. In addition, when the isocyanate group / amino group is within the above numerical range, the balance between the isocyanate group and the amino group is well maintained, and the concentration of the urea bond that becomes the bonding point in the coating film can be increased, and the weather resistance when formed into a coating film can be made good.

[0034] <Isocyanate group / hydroxyl group> The molar ratio (isocyanate group / hydroxyl group) of the isocyanate group of the polyisocyanate composition (C) to the hydroxyl group of the hydroxyl group-containing resin compound (A-2) is preferably 1 / 10 or more and 10 / 1 or less, more preferably 1 / 5 or more and 5 / 1 or less, and even more preferably 1 / 2 or more and 2 / 1 or less. When the isocyanate group / hydroxyl group is 1 / 10 or more, the main agent does not become too excessive, and the elongation at a low temperature of about -20 ° C. when formed into a coating film can be made good. In addition, when the isocyanate group / hydroxyl group is within the above numerical range, the balance between the isocyanate group and the hydroxyl group is well maintained, the concentration of the urethane bond that becomes the bonding point in the coating film can be increased, and the weather resistance when formed into a coating film can be made good.

[0035] <Polyisocyanate composition (C)> The coating composition of the present embodiment may contain a polyisocyanate composition (C).

[0036] The polyisocyanate composition (C) of the present embodiment may be a polyisocyanate component obtained from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and a polyester polyol having an average functionality of 2 and / or 3. The polyisocyanate composition (C) may be a polyisocyanate component that can be produced at once in the presence of an excess diisocyanate monomer by a known method using one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates as a raw material, by carrying out one or more reactions selected from the group consisting of biuret reaction, isocyanurate reaction, urethanation reaction, allophanate reaction, iminooxadiazinedione reaction, uretdione reaction, and uretone imino reaction, and by removing the unreacted diisocyanate monomer after the reaction is completed.

[0037] ·Diisocyanates The diisocyanate that is the raw material of the polyisocyanate contained in the polyisocyanate composition (C) of the present embodiment is one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

[0038] The aliphatic diisocyanate used in the present embodiment is not particularly limited, but is preferably an aliphatic diisocyanate having 4 to 30 carbon atoms, such as tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (hereinafter abbreviated as "HDI"), 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, and lysine diisocyanate. Among these, HDI is more preferable because of its industrial availability. The above-listed aliphatic diisocyanates may be used alone or in combination of two or more.

[0039] The alicyclic diisocyanate used in the present embodiment is not particularly limited, but is preferably an alicyclic diisocyanate having 8 to 30 carbon atoms, such as isophorone diisocyanate (hereinafter abbreviated as "IPDI"), 1,3-bis(isocyanatomethyl)-cyclohexane, 4,4'-dicyclohexylmethane diisocyanate, norbornene diisocyanate, and hydrogenated xylylene diisocyanate. Among them, IPDI is more preferable in terms of weather resistance and industrial availability. The above-mentioned alicyclic diisocyanates may be used alone or in combination of two or more. As the diisocyanate monomer, one or more aliphatic diisocyanates and one or more alicyclic diisocyanates can be used in combination.

[0040] The polyisocyanate composition of the present embodiment may further contain a polyisocyanate component obtained from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and a polyoxyalkylene polyol having an average number of functional groups of 2 to 4.

[0041] The polyisocyanate composition used in this embodiment can be produced by the methods described in WO 2018 / 163953 and WO 2018 / 163959.

[0042] The isocyanate content (hereinafter also referred to as "NCO content") of the polyisocyanate composition (C) used in this embodiment is preferably 5% by mass or more and 30% by mass or less with respect to the total amount (100% by mass) of the polyisocyanate composition. The NCO content is more preferably 6% by mass or more, and even more preferably 7% by mass or more. The NCO content is more preferably 28% by mass or less, and even more preferably 25% by mass or less. When the NCO content is 5% by mass or more, the drying property and curing property of the coating film are more easily maintained. When the NCO content is 30% by mass or less, when used as a curing agent of a coating composition, the viscosity increase of the coating is suppressed, and the appearance of the resulting coating film is easily improved. The NCO content of the polyisocyanate composition can be measured by the method described in the examples below.

[0043] The viscosity of the polyisocyanate composition (C) used in this embodiment at 25°C is preferably 100 mPa·s or more and 10000 mPa·s or less. The viscosity is more preferably 150 mPa·s or more, and even more preferably 200 mPa·s or more. The viscosity is more preferably 8000 mPa·s or less, and even more preferably 6000 mPa·s or less. When the viscosity is 100 mPa·s or more, when used as a curing agent for a coating composition, it is easy to suppress the viscosity increase of the coating and improve the appearance of the resulting coating film. When the viscosity is 10000 mPa·s or less, it is easy to maintain the drying property and curing property of the coating film. The viscosity of the polyisocyanate composition can be measured by the method described in the examples below.

[0044] The number average molecular weight of the polyisocyanate composition (C) used in this embodiment is preferably 250 or more and 4000 or less. The number average molecular weight is more preferably 300 or more and 3000 or less, and even more preferably 300 or more and 2500 or less. When the number average molecular weight is 250 or more, when used as a curing agent for a coating composition, the drying property and curing property of the resulting coating film are more easily maintained. When the number average molecular weight is 4000 or less, the viscosity increase of the coating is suppressed, and the appearance of the resulting coating film is easily improved. The number average molecular weight of the polyisocyanate composition can be measured by the method described in the examples below.

[0045] The average number of isocyanate groups in the polyisocyanate composition (C) used in this embodiment is preferably 2.0 or more and 10.0 or less. The average number of isocyanate groups is more preferably 2.2 or more, even more preferably 2.4 or more, and particularly preferably 2.6 or more. The average number of isocyanate groups is more preferably 9.0 or less, even more preferably 8.0 or less, and particularly preferably 7.0 or less. By having an average number of isocyanate groups of 2.0 or more, it is easier to maintain the drying property and curing property of the coating film. By having an average number of isocyanate groups of 10.0 or less, when used as a curing agent for a coating composition, it is easier to suppress the viscosity increase of the coating and improve the appearance of the resulting coating film. The average number of isocyanate groups in the polyisocyanate composition can be measured by the method described in the Examples below.

[0046] The diisocyanate monomer mass concentration of the polyisocyanate composition (C) used in this embodiment is preferably 1.0 mass% or less, more preferably 0.5 mass% or less, even more preferably 0.3 mass% or less, and particularly preferably 0.1 mass% or less, relative to the total amount (100 mass%) of the polyisocyanate composition. By setting the diisocyanate monomer mass concentration to 1.0 mass% or less, the drying property and curing property of the coating film are more easily maintained. The diisocyanate monomer mass concentration of the polyisocyanate composition can be measured by the method described in the examples below.

[0047] <Matte agent> The coating composition of the present embodiment may further contain a matting agent in addition to the above-mentioned wax particles (B). The matting agent is not particularly limited, but examples thereof include dry silica, precipitated silica, organic polymer fine particles, and organic polymer hollow particles.

[0048] <Other ingredients> The coating composition of the present embodiment may further contain other main components such as melamine resin, epoxy resin, polyurethane resin, etc., as necessary. In addition, when the above-mentioned hydroxyl group-containing (aqueous) resin compound has a carboxy group, an oxazoline group-containing compound and a carbodiimide group-containing compound may be blended. In addition, when the above-mentioned hydroxyl group-containing (aqueous) resin compound has a carbonyl group, a hydrazide group-containing compound and a semicarbazide group-containing compound may be blended. These compounds may be blended alone or in combination of two or more.

[0049] The coating composition of the present embodiment has a better appearance when formed into a coating film, and therefore may be appropriately added with known components as compounding agents for coating compositions. Examples of such components include solvents, surfactants, photosensitizers, foam stabilizers, foaming agents (foaming agents), foaming assistants, foam stabilizers, foam inhibitors (foam suppressors, foam breakers), emulsifiers, pigment dispersants, lubricants, propellants, thickeners, curing agents, polymerization initiators, pigments, plasticizers, adhesives, fillers, antifouling agents, rust inhibitors, slip agents, driers, stabilizers, ultraviolet absorbers, antibacterial and antifungal agents, and flame retardants.

[0050] <Method of producing coating composition> The coating composition of this embodiment is obtained by adding wax particles (B) to the above-mentioned aspartic acid ester compound (A-1) and / or hydroxyl group-containing resin compound (A-2) while mixing, and then mixing other components as necessary to obtain a coating base material (MC), and then blending the above-mentioned polyisocyanate composition (C), which is a curing agent component, into the coating base material (MC) and mixing using a known method. At this time, a solvent may or may not be used.

[0051] The coating composition of the present embodiment has a lower viscosity than conventional coating compositions, and therefore can be produced while maintaining workability even in high solid formulations.

[0052] The coating composition of this embodiment can also be obtained by blending the above-mentioned polyisocyanate composition (C), which is a curing agent component, with the wax particles (B) together with other components as necessary to obtain a coating curing agent, and then adding the coating curing agent together with other components as necessary to the above-mentioned aspartic acid ester compound (A-1) and / or hydroxyl group-containing resin compound (A-2) while mixing, and mixing using a known method. At this time, a solvent may or may not be used.

[0053] The content of the wax particles (B) in the coating hardener is 10% by weight or more and 200% by weight or less based on the total amount of the polyisocyanate composition (C). The content is more preferably 15% by weight or more and 150% by weight or less, and more preferably 25% by weight or more and 130% by weight or less. When the content is within the above range, the viscosity of the resulting coating composition and the matte property of the coating film can be compatible within an appropriate range.

[0054] <Application> The coating composition of the present embodiment is suitably used as a primer, intermediate coat or top coat on metals such as steel plates and surface-treated steel plates, plastics, ceramics such as inorganic materials, glass and concrete by roll coating, curtain flow coating, spray coating, electrostatic coating, bell coating, immersion, roller coating, brush coating or the like.

[0055] The coating composition of the present embodiment is suitably used to impart cosmetic properties, weather resistance, acid resistance, rust prevention, chipping resistance, adhesion, etc. to pre-coated metals including rust-resistant steel plates, painted parts of automobiles, painted parts of plastics, etc. The coating composition of the present embodiment is also useful as an adhesive, pressure-sensitive adhesive, elastomer, foam, surface treatment agent, etc.

[0056] In addition, the coating composition of the present embodiment has a flexible coating film and an increased crosslinking density, and is particularly excellent in weather resistance. Therefore, the coating composition of the present embodiment is suitably used for heavy-duty anticorrosion coating of structures that require long-term weather resistance, such as bridges, highways, transmission towers, and wind power generation facilities (towers, blades, etc.), which are exposed to severe environments such as wind, rain, snow, and temperature changes.

[0057] <Coating film> The coating film of the present embodiment is formed by curing the above-mentioned coating composition. The coating film of the present embodiment provides a coating composition that has an excellent matte appearance and also has good chemical resistance. The coating film of the present embodiment is obtained by applying the above-mentioned coating composition using a known method such as roll coating, curtain flow coating, spray coating, bell coating, electrostatic coating, etc., and then drying or baking at room temperature to harden the coating film. EXAMPLES

[0058] The present embodiment will be described in more detail below with reference to examples, but the present embodiment is not limited to these examples. The methods for measuring various physical properties and the methods for evaluating various properties are explained below. Unless otherwise specified, "parts" and "%" mean "parts by mass" and "% by mass".

[0059] Details of the materials used in the examples are as follows:

[0060] Wax particles (B): BYK-Chemie's product name CERAFLOUR913, average particle size = 18 μm BYK-Chemie's product name CERAFLOUR914, average particle size = 24 μm BYK-Chemie's product name CERAFLOUR915, average particle size = 34 μm BYK-Chemie's product name CERAFLOUR916, average particle size = 46 μm BYK-Chemie's product name CERAFLOUR917, average particle size = 42 μm BYK-Chemie's product name CERAFLOUR970, average particle size = 9 μm MP Gokyo Food & Chemical Co., Ltd. product name PropylTex100S, average particle size = 92 μm MP Gokyo Food & Chemical Co., Ltd. product name PropylTex50, average particle size = 165 μm

[0061] Aspartic acid ester compounds (A-1): "FEISPARTIC F-420" (Shenzhen Feiyang Protech Co., Ltd.), solid content 97%, amine value 201 "FEISPARTIC F-520" (Shenzhen Feiyang Protech Co., Ltd.), solid content 97%, amine value 191 Hydroxyl-containing resin compound (A-2): Trade name "ACRYDIC WGU-337" (DIC Corporation), solid content 69%, hydroxyl value 117 Pigment: Titanium oxide, product name "Tipaque CR-97" (manufactured by Ishihara Sangyo Kaisha, Ltd.)

[0062] Matting agent: Precipitated silica, product name "ACEMATT HK400" (manufactured by Evonik Japan Co., Ltd.), average particle size 6.3 μm Matting agent: Precipitated silica, product name "Nipsil E-170" (manufactured by Tosoh Silica Corporation), average particle size 3.4 μm Matting agent: precipitated silica, product name "Nipsil E-1011" (manufactured by Tosoh Silica Corporation), average particle size 1.5 μm

[0063] Anti-settling agent: organic bentonite, product name "Bentone SD-2" (manufactured by Elementis) Dehydrating agent: Molecular Sieve 3A (manufactured by Union Showa Co., Ltd.) UV absorber: TINUVIN-1130 (BASF) Light stabilizer: Product name TINUVIN-292 (manufactured by BASF) Dispersant: Product name BYK-163 (manufactured by BYK) Defoamer: BYK-141 (manufactured by BYK) Surface conditioner: BYK-331 (BYK) Solvent: Butyl acetate

[0064] <Method of measuring physical properties> [Physical Properties 1] (Measurement of the average particle size of wax particles (B)) The measurement was performed by a dry measurement method using a Malvern laser diffraction particle size distribution measuring device (Mastersizer 3000). The average particle size was determined as the D50 value based on volumetric measurement.

[0065] [Physical Properties 2] (NCO content (mass%)) The NCO content (isocyanate content, mass%) of the polyisocyanate composition (C) was measured as follows. After precisely weighing (Wg) 1 g or more and 3 g or less of the polyisocyanate composition produced in the production example in an Erlenmeyer flask, 20 mL of toluene was added to completely dissolve the polyisocyanate composition. Then, 10 mL of a 2N toluene solution of di-n-butylamine was added, and after completely mixing, the mixture was left at room temperature for 15 minutes. Furthermore, 70 mL of isopropyl alcohol was added to this solution and completely mixed. This solution was titrated with a 1N hydrochloric acid solution (factor F) using an indicator to obtain a titration value V2 mL. A similar titration operation was performed without using polyisocyanate to obtain a titration value V1 mL. From the obtained titration values ​​V2 mL and V1 mL, the NCO content (mass%) of the polyisocyanate was calculated based on the following formula.

[0066] (NCO content (mass%))=(V1-V2)×F×42 / (W×1000)×100

[0067] [Physical Properties 3] (Viscosity of polyisocyanate composition (C) (mPa s)) The viscosity of the polyisocyanate composition (C) was measured at 25° C. using an E-type viscometer (product name: RE-85R, manufactured by Toki Sangyo Co., Ltd.). A standard rotor (1°34′×R24) was used for the measurement. The rotation speed was set as follows.

[0068] (Rotation Speed) 100 rpm (less than 128 mPa s) 50 rpm (128 mPa s or more and less than 256 mPa s) 20 rpm (256 mPa s or more and less than 640 mPa s) 10 rpm (640 mPa s or more and less than 1280 mPa s) 5 rpm (1280 mPa·s or more and less than 2560 mPa·s) 2.5 rpm (2560 mPa s or more and less than 5120 mPa s) 1.0 rpm (5184 mPa s or more but less than 12960 mPa s)

[0069] [Physical Properties 4] (number average molecular weight) The number average molecular weight of the polyisocyanate composition (C) was determined as a number average molecular weight based on polystyrene standards by gel permeation chromatography (hereinafter abbreviated as "GPC") using the following device.

[0070] Equipment: Tosoh Corporation "HLC-8120GPC" (product name) Column: Tosoh Corporation "TSKgel SuperH1000" (product name) x 1 "TSKgel SuperH2000" (product name) x 1 "TSKgel SuperH3000" (product name) x 1 Carrier: Tetrahydrofuran Detection method: Differential refractometer

[0071] [Physical Properties 5] (average number of isocyanate groups) The average number of isocyanate groups in the polyisocyanate composition (C) was calculated from [Property 2] the NCO content and [Property 4] the number average molecular weight according to the following formula.

[0072] Average number of isocyanate groups = number average molecular weight × NCO content / 100 / 42

[0073] [Physical Properties 6] (Diisocyanate monomer mass concentration (mass%)) The diisocyanate mass concentration of the polyisocyanate composition (C) was determined as follows. First, a 20 mL sample bottle was placed on a digital balance and approximately 1 g of the sample was precisely weighed out. Next, 0.03 to 0.04 g of nitrobenzene (internal standard solution) was added and precisely weighed out. Finally, approximately 9 mL of ethyl acetate was added, and the lid was firmly closed and the mixture was thoroughly mixed to prepare the sample. The prepared sample was analyzed by gas chromatography under the following conditions and quantified.

[0074] Equipment: “GC-8A” manufactured by SHIMADZU Column: "Silicone OV-17" manufactured by Shinwa Kako Co., Ltd. Column oven temperature: 120°C Injection / detector temperature: 160℃

[0075] [Physical Properties 7] (Viscosity of paint base resin (MC) (mPa·s)) The viscosity of the resulting paint base material (MC) was measured at 25°C using an E-type viscometer (product name: RE-85R or RE-85U, manufactured by Toki Sangyo Co., Ltd.). A standard rotor (RE-85R: 1°34'×R24, RE-85U: 3°×R14) was used for the measurement. The rotation speed was set as follows:

[0076] (Rotation speed: RE-85R) 100 rpm (less than 128 mPa s) 50 rpm (128 mPa s or more and less than 256 mPa s) 20 rpm (256 mPa s or more and less than 640 mPa s) 10 rpm (640 mPa s or more and less than 1280 mPa s) 5 rpm (1280 mPa·s or more and less than 2560 mPa·s) 2.5 rpm (2560 mPa s or more and less than 5120 mPa s) (Rotation speed: RE-85U) 100 rpm (less than 5002 mPa s) 50 rpm (5002 mPa s or more and less than 10.0 Pa s) 20 rpm (10.0 Pa s or more and less than 25.01 Pa s) 10 rpm (25.01 Pa s or more and less than 50.02 Pa s) 5 rpm (50.02 Pa s or more and less than 100.0 Pa s) 2.5 rpm (100.0 Pa s or more and less than 200.1 Pa s)

[0077] (Evaluation Criteria) ◎: 5000mPa・s or less ○: 5001 mPa s or more, less than 20000 mPa s (20.0 Pa s) ×:20001mPa·s(20.0Pa·s) or more

[0078] [Physical Properties 8] (Solid content concentration (%) of coating composition (P)) After weighing an aluminum dish with a bottom diameter of 38 mm, about 1 g of the coating composition (P) of the Example or Comparative Example was weighed out (W1), adjusted to a uniform thickness, and then kept in an oven at 105°C for 3 hours. After the aluminum dish reached room temperature, the coating composition remaining on the aluminum dish was weighed out (W2). The obtained W1 and W2 were then introduced into the following formula to calculate the solid content concentration (%) of the coating composition.

[0079] (Solid content concentration (%) of coating composition (P)) = W2 / W1 × 100

[0080] <How to evaluate coating> [Rating 1] (Appearance of the coating) The coating compositions (P) obtained in the examples and comparative examples were applied to a glass plate with an applicator so that the dry film thickness was 40 μm to 60 μm. After application, the coating was cured for 7 days under conditions of 23° C. and 50 RH% humidity to obtain each coating film. The appearance of each coating film was evaluated according to the following evaluation criteria.

[0081] (Evaluation Criteria) A: The surface is very smooth and there are no irregularities. B: The surface is smooth, but there are some small irregularities. C: The surface is very uneven and wrinkled.

[0082] [Rating 2] (Paint film gloss) The coating compositions (P) obtained in the examples and comparative examples were applied to a glass plate with an applicator so that the dry film thickness was 40 μm or more and 60 μm or less. After application, the coatings were cured for 7 days under conditions of 23°C and humidity of 50 RH% to obtain each coating film. The gloss value of the coating film was then measured at 60°-60° using a gloss meter (Haze-Gloss, manufactured by BYK-Garner) and evaluated according to the following evaluation criteria.

[0083] (Evaluation Criteria) ○: Gloss value is 40 or less, and matte finish is good ×: Gloss value exceeds 40, and matte finish is insufficient.

[0084] [Rating 3] (Alkaline resistance of coating film) The coating compositions (P) obtained in the examples and comparative examples were applied to a glass plate with an applicator so that the dry film thickness was 40 μm or more and 60 μm or less. After application, the coating was cured for 7 days under conditions of 23°C and humidity of 50 RH% to obtain each coating film. A rubber ring was placed on the obtained coating film, and a 10% by mass aqueous solution of sodium hydroxide was dropped on the center part. After immersion at 23°C for 24 hours, the alkali resistance was evaluated according to the following evaluation criteria based on the state of blisters generated between the glass substrate / coating film.

[0085] (Evaluation Criteria) ○: No change in appearance ×: Cloudiness, dissolution, or blister swelling.

[0086] <Manufacture of paint base resin (MC)> [Production Example 1] A metal container was charged with 33.5 parts of FEISPARTIC F-420 as an aspartic acid ester compound (A-1), 36.9 parts of Typec CR-97 as a pigment, and 2.3 parts of BYK-163, 0.35 parts of BYK-141, 1.8 parts of Bentone SD2, 3.5 parts of Molecular Sieve 3A (abbreviated as "MS 3A" in the table) as additives, and 18 parts of butyl acetate as a solvent, and then the mixture was stirred and mixed with a disperser to obtain a mixture. Next, the entire amount of the mixture obtained and glass beads (the same amount as the total mass of the mixture) were placed in a dispersing machine (Taihei Systems Co., Ltd., tabletop SG Mill 1500W type) and the pigment was dispersed until the pigment particle diameter was 20 μm or less, thereby preparing a pigment dispersion paint. Furthermore, 96.4 parts of the obtained pigment dispersion paint was added with 19 parts of CERAFLOUR913 as wax particles (B), 1.1 parts of TINUVIN-1130, 0.70 parts of TINUVIN-292, and 0.12 parts of BYK-331 as additives, and 18 parts of butyl acetate as a solvent, and the mixture was stirred and mixed using a disperser until homogenous, to obtain a paint base agent (mc-1).

[0087] [Manufacturing Examples 2 to 6] Coating base materials (mc-2) to (mc-6) were obtained in the same manner as in [Production Example 1], except that the materials shown in [Table 1] were used as the wax particles (B).

[0088] [Production Example 7] A paint base agent (mc-7) was obtained in the same manner as in [Production Example 1], except that the material shown in [Table 2] was used as the aspartic acid ester compound (A-1).

[0089] [Production Example 8] A paint base agent (mc-8) was obtained in the same manner as in [Production Example 1], except that the material shown in [Table 2] was used as the hydroxyl group-containing resin compound (A-2) instead of the aspartic acid ester compound (A-1).

[0090] [Manufacturing Examples 9-12] Except for changing the compounding amounts of the materials as shown in [Table 2], the same procedure as [Production Example 2] was followed to obtain paint base materials (mc-9) to (mc-12).

[0091] [Comparative Manufacturing Examples 1 to 6] Except for changing the types and amounts of materials as shown in Table 3, the same procedure as in Production Example 1 was followed to obtain paint base agents (mc-13) to (mc-18).

[0092] [Table 1]

[0093] [Table 2]

[0094] [Table 3]

[0095] <Production of polyisocyanate composition (C)> [Synthesis Example 1] A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen inlet, and dropping funnel was filled with nitrogen and charged with 100 parts of HDI and 33.7 parts of polycaprolactone triol with a number average molecular weight of 850 and a hydroxyl value of 198. The temperature inside the reactor was kept at 95°C for 90 minutes while stirring to carry out a urethane reaction. The cooled reaction liquid was filtered, and unreacted HDI was removed using a thin-film evaporator. A polyisocyanate composition (c-1) was obtained with an NCO content of 9.0% by mass, a viscosity at 25°C of 4980 mPa s, a number average molecular weight of 1520, an average number of isocyanate groups of 3.3, and an HDI monomer mass concentration of 0.2% by mass.

[0096] [Synthesis Example 2] A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen inlet, and dropping funnel was conditioned with nitrogen, and 100 parts of HDI, 6.9 parts of polycaprolactone triol with a number average molecular weight of 550 and a hydroxyl value of 305, and 12.8 parts of polytetramethylene glycol with a number average molecular weight of 1000 and a hydroxyl value of 112 were charged. The temperature inside the reactor was kept at 90°C for 1 hour while stirring, and a urethane reaction was carried out. The cooled reaction liquid was filtered, and unreacted HDI was removed using a thin-film evaporator. A polyisocyanate composition (c-2) was obtained with an NCO content of 8.9% by mass, a viscosity of 2740 mPa·s at 25°C, a number average molecular weight of 1570, an average number of isocyanate groups of 3.3, and an HDI monomer mass concentration of 0.2% by mass.

[0097] [Synthesis Example 3] A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel was placed in a nitrogen atmosphere, 100 parts of HDI was charged, and the temperature inside the reactor was maintained at 60°C while stirring. 0.15 parts of a solution of tetrabutylammonium acetate, an isocyanurate reaction catalyst, diluted to 10% by mass with 2-ethyl-1-hexanol was added thereto, and an isocyanurate reaction was carried out. When the NCO content of the reaction liquid reached 43.8% by mass, phosphoric acid was added to stop the reaction. The reaction liquid was then maintained at 90°C for 1 hour. The cooled reaction liquid was filtered, and unreacted HDI was removed using a thin-film evaporator. A polyisocyanate composition (c-3) was obtained with an NCO content of 23.1% by mass, a viscosity of 1350 mPa·s at 25°C, a number average molecular weight of 590, an average number of isocyanate groups of 3.2, and an HDI monomer mass concentration of 0.1% by mass.

[0098] <Production, application and evaluation of coating composition (P)> [Example 1] A metal container was charged with 117.4 parts of the paint base agent (mc-1) obtained in Production Example 1 and Synthesis Example 1, 61.7 parts of the polyisocyanate composition (c-1), and 6 parts of butyl acetate as a solvent, and then the mixture was stirred and mixed with a disperser to obtain a paint composition (p-1).

[0099] [Examples 2 to 14] [Comparative Examples 1 to 6] Except for changing the base paint (MC) and the polyisocyanate composition (C) as shown in [Table 4], [Table 5] and [Table 6], the same procedure as in [Example 1] was carried out to obtain coating compositions (p-2) to (p-20).

[0100] Various physical properties and evaluation results are shown in Tables 4, 5 and 6 below.

[0101] [Table 4]

[0102] [Table 5]

[0103] [Table 6]

[0104] As shown above, in Examples 1 to 14 which met all the above-mentioned requirements, the viscosity of the main component (MC) was low at 20,000 mPa·s or less, and the viscosity increase could be suppressed even in paints with a high solid content concentration of 70% by weight or more. In addition, the matte finish of the coating film was good, at 40 or less at 60° gloss. Furthermore, the appearance and chemical resistance of the coating film obtained were good.

[0105] Furthermore, in a comparison of the wax particles in which the average particle size was changed (Examples 1 to 6), it was found that the matte properties of the coating film tended to be improved as the average particle size increased.

[0106] Furthermore, in a comparison of the cases where the amount of wax particles was changed (Example 7, Example 10, Example 11, Example 12), a higher amount tended to improve the matte finish of the coating film, while a lower amount tended to reduce the viscosity of the base agent.

[0107] On the other hand, when silica, which has been used conventionally as a matting agent, was used (Comparative Example 1 and Comparative Example 2), increasing the amount of silica resulted in too high viscosity, while decreasing the amount of silica resulted in insufficient matting. In addition, paints with poor chemical resistance and high viscosity had poor appearances when made into coating films.

[0108] Furthermore, when wax particles having an average particle size greater than 100 μm were used instead of the wax particles (Comparative Example 5), and when wax particles having an average particle size smaller than 10 μm were used (Comparative Example 6), sufficient matte properties were not obtained.

[0109] Even when the particle size of silica was changed (Comparative Example 3 and Comparative Example 4), the viscosity became too high and sufficient matte properties were not obtained compared to Comparative Example 2. In addition, the chemical resistance was poor, and the appearance of the coating film was poor. [Industrial Applicability]

[0110] According to the coating composition of the present embodiment, even in a coating having a high solid content of 70% by weight or more, the increase in viscosity is suppressed, and the coating has an excellent matte appearance. In addition, when formed into a coating film, the chemical resistance is good.

Claims

1. The composition comprises an aspartic acid ester compound (A-1) and / or a hydroxyl group-containing resin compound (A-2), and wax particles (B), the wax particles (B) have an average particle size of 10 μm or more and 100 μm or less, and a content of 10% by weight or more and 200% by weight or less based on the total amount of the aspartic acid ester compound (A-1) and / or the hydroxyl group-containing resin compound (A-2); A paint base having a solids concentration of 70% by weight or more.

2. 2. The base material for a paint according to claim 1, wherein the wax particles (B) are particles containing at least one wax selected from the group consisting of polyolefin wax, paraffin wax, microcrystalline wax, and aliphatic wax.

3. A coating composition comprising the base coating material according to claim 1 or 2 and a polyisocyanate composition (C), and having a solids concentration of 70% by weight or more.

4. A coating film obtained by curing the coating composition according to claim 3.

5. A polyisocyanate composition (C) and wax particles (B), The wax particles (B) have an average particle size of 10 μm or more and 100 μm or less, and a content of 10% by weight or more and 200% by weight or less based on the total amount of the polyisocyanate composition (C), A coating hardener having a solids concentration of 70% by weight or more.

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