Paint compositions, two-component paint compositions, coating films, and painted products

Abstract

To provide paint compositions and the like that are highly environmentally friendly and have excellent performance characteristics. [Solution] According to one aspect of the present invention, a paint composition is provided which has a solid content concentration of 70% by mass or more and comprises a compound (A) containing an active hydrogen group and a polyisocyanate compound (B), wherein the compound (A) containing an active hydrogen group comprises a polyaspartate ester (A1) and a resin (A2) having a hydroxyl group in its side chain, and the weight-average molecular weight of the resin (A2) having a hydroxyl group in its side chain is in the range of 2500 to 20000.

Description

[Technical Field]

[0001] The present invention relates to paint compositions, two-component paint compositions, coating films, and coated products. [Background technology]

[0002] In recent years, attempts have been made to include polyaspartate ester compounds in paint compositions in order to impart chemical resistance and hardness to the resulting coating films (see, for example, Patent Document 1).

[0003] Another attempt in the paint field involves improving the solid content concentration (reducing organic solvents) of solvent-based paints from the perspective of reducing VOC emissions and improving the working environment (see, for example, Patent Document 2). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-64931 [Patent Document 2] International Publication No. 2021 / 205934 Brochure [Overview of the project] [Problems that the invention aims to solve]

[0005] However, there is still room for development in materials that can meet both of the above requirements. Specifically, the paint composition embodied in Patent Document 1 has a low solid content concentration, and the paint composition embodied in Patent Document 2 also has room for improvement in terms of handling and performance as a cured coating film.

[0006] In view of the above circumstances, the present invention aims to provide a paint composition and the like that is highly environmentally friendly and has excellent performance in various aspects. [Means for solving the problem]

[0007] According to one aspect of the present invention, a paint composition is provided which has a solid content concentration of 70% by mass or more and comprises a compound (A) containing an active hydrogen group and a polyisocyanate compound (B), wherein the compound (A) containing an active hydrogen group comprises a polyaspartate ester (A1) and a resin (A2) having hydroxyl groups in its side chain, and the weight-average molecular weight of the resin (A2) having hydroxyl groups in its side chain is in the range of 2500 to 20000.

[0008] According to the above embodiment, a paint composition and the like that is highly environmentally friendly and has excellent performance is provided. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below. The various features shown in the embodiments below can be combined with each other. In this specification, unless otherwise specified, "~" represents the following from the above. Also, "(meth)acrylic(acid)" is a general term for "methacrylic(acid)" and "acrylic(acid)", and "(meth)acrylate" is a general term for "methacrylate" and "acrylate".

[0010] <Paint composition> The paint composition of this embodiment is as follows. A paint composition, The solid content concentration is 70% by mass or more. The compound comprises a compound (A) containing an active hydrogen group and a polyisocyanate compound (B), The compound (A) containing the active hydrogen group comprises a polyaspartate ester (A1) and a resin (A2) having hydroxyl groups in its side chain. A paint composition in which the weight-average molecular weight of the resin (A2) having hydroxyl groups in its side chains is in the range of 2500 to 20000. The components constituting the paint composition of this embodiment, the method for manufacturing the paint composition, and its uses will be described below.

[0011] [Compounds containing active hydrogen groups (A)] The coating composition of this embodiment contains a compound (A) containing an active hydrogen group. Hereinafter, such a compound may be simply referred to as "compound (A)".

[0012] In this embodiment, the compound (A) provides a cured film by reacting with a polyisocyanate compound (B) described later. Specifically, the active hydrogen group provided in the compound (A) may be a functional group selected from the group consisting of a hydroxyl group, a hydrosulfide group, and an amino group. When these functional groups react with the polyisocyanate compound (B), a urethane bond, a thiourethane bond, or a urea bond is formed, thereby forming a cured film as the coating composition. The components that may be included as the compound (A) in this embodiment will be described below.

[0013] (Polyaspartic acid ester (A1)) The compound (A) in this embodiment contains a polyaspartic acid ester (A1). This polyaspartic acid ester (A1) typically contains a secondary amino group in its chemical structure, and the crosslinking reaction with the polyisocyanate compound (B) described later proceeds, contributing to the formation of a cured coating film. Although not necessarily limited thereto, the polyaspartic acid ester (A1) is represented by, for example, the following formula (I).

[0014] [Chemical formula]

[0015] In formula (I), Y 11 is an m-valent organic group. R 11 and R 12 are each independently an alkyl group having 1 or more and 10 or less carbon atoms. m is an integer of 2 or more.

[0016] Y in formula (I) 11 is not particularly limited, but is preferably an m-valent cyclic or chain aliphatic hydrocarbon group or a polyoxyalkylene polyamine residue having a number average molecular weight of 25 to 5000.

[0017] For example, Y 11 is a divalent aliphatic hydrocarbon group. Examples of divalent aliphatic hydrocarbon groups include alkylene, cycloalkylene, cycloalkylalkylene, alkylcycloalkylene, alkylenebiscycloalkylene, alkylenebis(alkylcycloalkylene), and cycloalkylenebisalkylene.

[0018] Here, alkylene is preferably an alkylene having 1 to 8 carbon atoms, cycloalkylene is preferably a cycloalkylene having 5 to 6 carbon atoms, alkyl is preferably an alkyl having 1 to 8 carbon atoms, and cycloalkyl is preferably a cycloalkyl having 5 to 6 carbon atoms.

[0019] Also, Y 11 This may be a polyoxyalkylene polyamine residue. A polyoxyalkylene polyamine residue refers to a group obtained by removing the primary amino groups at both ends of a polyoxyalkylene polyamine. The polyoxyalkylene polyamine residue may have a side chain. The polyoxyalkylene polyamine residue is preferably a polyoxyethylene polyamine residue, a polyoxypropylene polyamine residue, a polyoxybutylene polyamine residue, or a polyoxyethylene polyoxypropylene polyamine residue. The polyoxyalkylene polyamine residue is more preferably -(CH(CH3)-CH2-O)x-CH2-CH(CH3)- (where x is an integer from 3 to 6).

[0020] Also, Y 11It may be an amine residue for the polyamine shown below. The amine residue refers to a group obtained by removing the primary amino groups at both ends from the polyamine shown below. Examples of the polyamine here include ethylene diamine, 1,2-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 2,5-diamino-2,5-dimethylhexane, 2,2,4- and / or 2,4,4-trimethyl-1,6-diaminohexane, 1,11-diaminoundecane, 1,12-diaminododecane, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 2,4- or 2,6-hexahydrotolylene diamine, 2,4'- or 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 2,4,4'-triamino-5-methyldicyclohexylmethane, etc., and m-valent polyamines can be mentioned.

[0021] R 11 and R 12 are, as described above, alkyl groups having 1 to 10 carbon atoms. Typically, this R 11 [[ID=B]]and R 12 preferably do not contain an active hydrogen group in their chemical structures. Also, R 11 and R 12 are more preferably each independently a methyl group, an ethyl group, a propyl group or a butyl group.

[0022] [[ID=B]] In formula (I), m is preferably an integer of 2 or more and 6 or less, more preferably an integer of 2 or more and 4 or less, and even more preferably 2.

[0023] It should be noted that there is an incorrect "ID=B" in the original text which is kept as is during translation. If this is a mislabel and needs correction, it should be adjusted accordingly in the original text before translation for a more accurate result.This polyaspartate ester (A1) may be a commercially available product. Examples of commercially available product names include: Desmophene NH1220, Desmophene NH1420, Desmophene NH1422, Desmophene NH1423, Desmophene NH1520, Desmophene NH1521, Desmophene NH1523, Desmophene NH1723LF, Desmophene NH2885, Desmophene NH2886 (all are product names; "Desmophene" is a registered trademark, manufactured by Covestro), FEISPARTIC F220, FEISPARTIC F420, FEISPARTIC F520, FEISPARTIC F2850, FEISPARTIC F2872, FEISPARTIC F221, FEISPARTIC Examples include "F321", "FEISPARTIC F525", "FEISPARTIC F421", "FEISPARTIC F524", "FEISPARTIC F330", "FEISPARTIC D2925", "FEISPARTIC D2903" (all product names, manufactured by Feiyang Protech), "TSE-EZASP7980", "TSE-EZASP7981", "TSE-EZASP9033", "TSE-EZASP8443" (all product names, manufactured by TSE Industries), "Altor200", "Altor201", "Altor202", "Altor205LV" (all product names, manufactured by Cargill), etc.

[0024] The proportion of polyaspartate ester (A1) in the total compound (A) contained in the paint composition can be appropriately set according to the intended use of the paint composition. As an example, when the total compound (A) contained in the paint composition is 100 parts by mass, the content of polyaspartate ester (A1) is preferably in the range of 20 to 85 parts by mass, more preferably in the range of 25 to 80 parts by mass, and even more preferably in the range of 30 to 75 parts by mass. Setting the content within this range makes it easier to impart various properties such as weather resistance to the resulting coating film.

[0025] (Resin with hydroxyl groups in the side chain (A2)) Furthermore, compound (A) in this embodiment includes a resin (A2) having hydroxyl groups in its side chains. Here, the weight-average molecular weight of the resin (A2) having hydroxyl groups in its side chains is in the range of 2500 to 20000. In other words, by using such a resin (A2) having hydroxyl groups in its side chains, it is possible to improve the coating properties of the paint composition.

[0026] Resins (A2) having hydroxyl groups in their side chains have a structure in which monomers having ethylenically unsaturated double bonds are polymerized. In a typical embodiment, resins (A2) having hydroxyl groups in their side chains have structural units represented by the following formula (II).

[0027] [ka]

[0028] In the structural unit represented by formula (II), the symbols are as follows: R 21 , R 22 and R 23 Each of these is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Also, R 21 and R 22 These may be linked together to form a ring structure including the main chain of the polymer. The ring structure here may be a 4- to 8-membered ring. 21 This is a single bond or a linking group with 1 to 12 carbon atoms.21 It may have heteroatoms in its structure, and typically may have bonds selected from ester bonds, ether bonds, amide bonds, and urethane bonds. On the other hand, Y 21 n may be an alkylene group having 1 to 12 carbon atoms, or an arylene group having 6 to 12 carbon atoms. n is the number of repeating structural units represented by formula (II). This n is set appropriately within the range that satisfies the aforementioned weight-average molecular weight.

[0029] In a more typical embodiment, R 21 and R 23 Each of these is a hydrogen atom, and R 22 is a hydrogen atom or a methyl group. Also, Y 21 This may be an alkylene group having an ester bond in its structure. In other words, typical examples of such structures include structural units derived from hydroxymethyl methacrylate and hydroxymethyl acrylate. In other words, the paint composition of this embodiment preferably contains a (meth)acrylic polyol as the resin (A2) having a hydroxyl group in its side chain.

[0030] The resin (A2) having hydroxyl groups in its side chains may also have structural units that do not correspond to the structural unit represented by formula (II) described above. In other words, the resin (A2) having hydroxyl groups in its side chains may be a resin containing the structural unit represented by formula (II), but it does not necessarily have to be a homopolymer. When the resin (A2) having hydroxyl groups in its side chains is a copolymer, the other monomers are appropriately selected from monomers that can constitute a polymer, such as (meth)acrylic acid, (meth)acrylic acid esters, (meth)acrylamide, ethylene, propylene, cyclohexene, norbornene, etc. Here, examples of (meth)acrylic acid esters include ester compounds obtained by condensing methacrylic acid or acrylic acid with an alcohol having 1 to 10 (preferably 1 to 6) carbon atoms.

[0031] In resin (A2) having hydroxyl groups in its side chains, the proportion of structural units represented by formula (II) in the total structural units can be set as appropriate. On the other hand, from the viewpoint of increasing reactivity with polyisocyanate compound (B), the proportion of structural units represented by formula (II) in the total structural units of resin (A2) having hydroxyl groups in its side chains is preferably 5 mol% or more, more preferably 8 mol% or more, even more preferably 10 mol% or more, and particularly preferably 12 mol% or more. On the other hand, the proportion of structural units represented by formula (II) in the total structural units of resin (A2) having hydroxyl groups in its side chains is preferably 75 mol% or less, more preferably 60 mol% or less, and even more preferably 50 mol% or less. By setting it within such a range, it is easier to ensure appropriate reactivity with polyisocyanate compound (B). Furthermore, the proportion of structural units represented by formula (II) in the total structural units of resin (A2) having hydroxyl groups in its side chains may be 100 mol% (i.e., all structural units of resin (A2) having hydroxyl groups in its side chains may correspond to structural units represented by formula (II)).

[0032] Furthermore, from another perspective, it is preferable that the resin (A2) having hydroxyl groups in its side chains has a set hydroxyl value. In a typical embodiment, the hydroxyl value of the resin (A2) having hydroxyl groups in its side chains is preferably in the range of 40 mg KOH / g to 200 mg KOH / g, more preferably in the range of 45 mg KOH / g to 180 mg KOH / g, and even more preferably in the range of 50 mg KOH / g to 160 mg KOH / g. Setting it within such a range makes it easier to ensure appropriate reactivity with the polyisocyanate compound (B).

[0033] Furthermore, the weight-average molecular weight of the resin (A2) having hydroxyl groups in its side chains can be appropriately set within the range described above, but the lower limit is preferably 2800 or higher, and more preferably 3000 or higher. The upper limit of the weight-average molecular weight of the resin (A2) having hydroxyl groups in its side chains is preferably 18000 or lower, and more preferably 15000 or lower. Setting it within this range can contribute to further improvement of the coating properties of the paint composition. Note that the weight-average molecular weight as described above can be adjusted by the conditions when synthesizing the resin (A2) having hydroxyl groups in its side chains (type and amount of polymerization initiator, polymerization temperature, polymerization time, etc.).

[0034] The proportion of resin (A2) having hydroxyl groups in its side chains in the total compound (A) contained in the paint composition can be appropriately set according to the intended use of the paint composition. As an example, when the total compound (A) contained in the paint composition is 100 parts by mass, the content of resin (A2) having hydroxyl groups in its side chains is preferably in the range of 15 to 80 parts by mass, more preferably in the range of 20 to 75 parts by mass, and even more preferably in the range of 25 to 70 parts by mass. Setting it within this range makes it easier to improve the coatability of the paint composition.

[0035] In this embodiment, it is also preferable to set the blending ratio of polyaspartate ester (A1) to resin having hydroxyl groups in the side chain (A2). For example, when the content of polyaspartate ester (A1) is 100 parts by mass, the content of resin having hydroxyl groups in the side chain (A2) is preferably 20 parts by mass or more, more preferably 25 parts by mass or more, and even more preferably 30 parts by mass or more. By adjusting the blending ratio in this way, it is easy to improve the coatability of the paint composition. On the other hand, when the content of polyaspartate ester (A1) is 100 parts by mass, the content of resin having hydroxyl groups in the side chain (A2) is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, and even more preferably 100 parts by mass or less. By adjusting the blending ratio in this way, it is easy to improve the weather resistance and other properties of the paint film obtained from the paint composition.

[0036] (Other compound (A)) Compound (A) may include a combination of various compounds having active hydrogen groups, other than the polyaspartate ester (A1) and the resin (A2) having hydroxyl groups in its side chains. The types and amounts of these compounds are arbitrary.

[0037] The content of compound (A) relative to 100 parts by mass of the total solid content of the paint composition can be set as appropriate, but for example, it may be in the range of 20 to 80 parts by mass, 25 to 75 parts by mass, or 30 to 70 parts by mass.

[0038] [Polyisocyanate compound (B)] The coating composition of this embodiment contains a polyisocyanate compound (B). Here, polyisocyanate compound (B) refers to a compound having two or more isocyanate groups in its molecule (a so-called "polyfunctional isocyanate compound"). The number of isocyanate groups contained in the molecule can be set as appropriate, but is preferably 2 to 6, and more preferably 2 to 4.

[0039] In this specification, polyisocyanate compound (B) may include a blocked isocyanate compound in which the isocyanate group is protected with a predetermined blocking agent. In terms of storage stability, it is preferable that polyisocyanate compound (B) includes a blocked isocyanate compound. On the other hand, it is also preferable that polyisocyanate compound (B) includes an unblocked polyisocyanate compound, from the viewpoint of reducing manufacturing costs and realizing a paint composition that is easily available.

[0040] Examples of polyisocyanate compounds (B) include aliphatic diisocyanates such as lysine diisocyanate, hexamethylene diisocyanate, and trimethylhexane diisocyanate; cyclic aliphatic diisocyanates such as hydrogenated xylylene diisocyanate, isophorone diisocyanate, methylcyclohexane-2,4-(or 2,6)-diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and 1,3-(isocyanatomethyl)cyclohexane; and isocyanates with three or more functions, such as lysine triisocyanate. Furthermore, isocyanurates and biuret-type adducts, which are polymers of polyisocyanate compound (B), as well as polyisocyanate compound (B) added to polyhydric alcohols or low molecular weight polyester resins, can also be used as polyisocyanate compound (B).

[0041] Incidentally, known polyisocyanate compounds (B) include biuret type, isocyanurate type, adduct type, and allophanate type. Any of these can be used in this embodiment. Among these, isocyanurate type isocyanate compounds, that is, polyfunctional isocyanates having a cyclic skeleton of isocyanuric acid, are preferred.

[0042] The polyisocyanate compound (B) may be a so-called blocked isocyanate. In other words, some or all of the isocyanate groups of the polyisocyanate compound (B) may be in the form of blocked isocyanate groups, which are blocked by a protecting group. For example, isocyanate groups are blocked by active hydrogen compounds such as alcohols, phenols, lactams, oximes, and active methylene compounds to form blocked isocyanate groups.

[0043] The amount of polyisocyanate compound (B) relative to 100 parts by mass of the total solid content of the paint composition can be set as appropriate, but for example, it may be in the range of 20 to 80 parts by mass, 25 to 75 parts by mass, or 30 to 70 parts by mass.

[0044] Furthermore, in the paint composition of this embodiment, it is preferable that the ratio of the number of moles of isocyanate groups contained in the polyisocyanate compound (B) to the number of moles of active hydrogen groups contained in compound (A) (amount of isocyanate groups / amount of active hydrogen groups) is adjusted. Typically, the ratio of the number of moles of isocyanate groups contained in the polyisocyanate compound (B) to the number of moles of active hydrogen groups contained in compound (A) (amount of isocyanate groups / amount of active hydrogen groups) is preferably in the range of 0.85 to 1.15, and more preferably in the range of 0.9 to 1.1. Setting it within this range makes it easier to obtain a strong cured coating film.

[0045] (Silicon-containing compounds (C)) Furthermore, the paint composition of this embodiment may also contain a silicon-containing compound (silicon-containing compound (C)) to improve the adhesion of the resulting coating film. Typical materials are shown below.

[0046] (Silane coupling agent (C1)) The coating composition of this embodiment may contain a silane coupling agent (C1). By including such a silane coupling agent (C1) in the coating composition, the adhesion of the coating film to the substrate can be improved. The silane coupling agent (C1) may be selected from known materials, but typical examples include aminosilane, epoxysilane, (meth)acrylicsilane, mercaptosilane, vinylsilane, ureidosilane, and sulfidosilane.

[0047] Examples of aminosilanes include bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldiethoxysilane, or N-phenyl-γ-aminopropyltrimethoxysilane. Examples of epoxysilanes include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, or β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidylpropyltrimethoxysilane, etc. Examples of acrylicsilanes include γ-(methacryloxypropyl)trimethoxysilane, γ-(methacryloxypropyl)methyldimethoxysilane, or γ-(methacryloxypropyl)methyldiethoxysilane. Examples of mercaptosilanes include 3-mercaptopropyltrimethoxysilane. Examples of vinylsilanes include vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, or vinyltrimethoxysilane. Examples of ureidosilanes include 3-ureidopropyltriethoxysilane. Examples of sulfidosilanes include bis(3-(triethoxysilyl)propyl) disulfide or bis(3-(triethoxysilyl)propyl) tetrasulfide.

[0048] When a silane coupling agent (C1) is included in the paint composition, the amount of silane coupling agent (C1) can be set as appropriate. On the other hand, when the total solid content of the paint composition is 100 parts by mass, the amount of silane coupling agent (C1) may be, for example, in the range of 0.1 to 5 parts by mass, in the range of 0.3 to 4 parts by mass, or in the range of 0.5 to 3 parts by mass.

[0049] (Alkoxysilicate polymer (C2)) The paint composition of this embodiment may contain an alkoxysilicate polymer (C2). This alkoxysilicate polymer (C2) is a hydrolyzable alkoxysilicate polymer represented by the general formula Si(OR)4. Here, R is a methyl group or an ethyl group.

[0050] This alkoxysilicate polymer (C2) can be made from commercially available materials. For example, MKC silicate MS51, MKC silicate MS56, MKC silicate MS57, MKC silicate MS56S (all trade names, manufactured by Mitsubishi Chemical Corporation); and methyl silicate 51, methyl silicate 53A, ethyl silicate 40, and ethyl silicate 48 (all trade names, manufactured by Colcoat Corporation), manufactured by Colcoat Corporation, are readily available materials and are therefore preferably used.

[0051] When a paint composition contains an alkoxysilicate polymer (C2), the content of the alkoxysilicate polymer (C2) can be set as appropriate. On the other hand, when the total solid content of the paint composition is 100 parts by mass, the content of the alkoxysilicate polymer (C2) may be, for example, in the range of 0.05 to 5 parts by mass, in the range of 0.1 to 4 parts by mass, or in the range of 0.2 to 3 parts by mass.

[0052] (Pigment (D)) The paint composition of this embodiment may further contain a pigment (D). By including a pigment (D) in the paint composition, it is possible to give the paint film a desired color and enhance the aesthetic appeal of the paint film. In addition, depending on the type of pigment (D), rust prevention properties can be improved.

[0053] The pigments (D) that can be used are not particularly limited. For example, known coloring pigments such as inorganic pigments and organic pigments can be used. Specifically, examples include, but are not limited to, white pigments such as titanium dioxide (e.g., CR-95 manufactured by Ishihara Sangyo Co., Ltd.), lead white, lead sulfate, lithopone, and antimony white; black pigments such as carbon black, acetylene black, lamp black, graphite, iron black (black iron oxide), and aniline black; yellow pigments such as naphthol yellow S, Hansa yellow, pigment yellow L, benzidine yellow, permanent yellow, and pyrite (yellow iron oxide); orange pigments such as chrome orange, chrome vermilion, and permanent orange; brown pigments such as iron oxide and amber; red pigments such as red iron oxide, red lead, permanent red, quinacridone-based red pigments, and diketopyrrolopyrrole-based red pigments; purple pigments such as fast violet and methyl violet lake; blue pigments such as ultramarine, Prussian blue, and indigo; and green pigments such as chrome green.

[0054] As the pigment (D), an extender pigment may be used. The extender pigments that can be used are not particularly limited, but examples include barita powder, barium sulfate, barium carbonate, calcium carbonate, gypsum, clay, silica, white carbon, diatomaceous earth, talc, magnesium carbonate, hydrated magnesium silicate, alumina white, gloss white, mica powder, etc.

[0055] The pigment (D) is preferably one that can withstand the temperature during the baking of the paint (i.e., one that undergoes little change in color, etc., during baking). In this respect, inorganic pigments and extender pigments are preferably used. Of course, organic pigments can also be used, provided that baking conditions and other factors are set.

[0056] Furthermore, pigment (D) may include rust-preventive pigments known in the field of paints. Examples of rust-preventive pigments include phosphate compounds, phosphate compounds, molybdenate compounds, bismuth compounds, and metal ion exchange silica.

[0057] The paint composition of this embodiment may contain only one pigment (D), or it may contain two or more pigments.

[0058] The amount of pigment (D) in the paint composition of this embodiment is not particularly limited and can be adjusted as appropriate in consideration of other properties. For example, when the total solid content of the paint composition is 100 parts by mass, the pigment (D) content can be 10 to 70 parts by mass or 20 to 60 parts by mass.

[0059] (Solvent (S)) The paint composition of this embodiment may contain a solvent (S) as a volatile component. By including the solvent (S) in this way, the paint composition of this embodiment becomes easier to coat. The usable solvent (S) is not particularly limited and may be an organic solvent or water. One or more solvents known in the art of paints can be used as the solvent (S). As for organic solvents, one or more can be used from among alcohol-based solvents, ketone-based solvents, ester-based solvents, ether-based solvents, glycol ether-based solvents, aliphatic hydrocarbon-based solvents (chain, branched, or cyclic), carbonate-based solvents, etc. Furthermore, this solvent (S) may be a so-called thinner (urethane thinner). Furthermore, since the solvent (S) can typically disperse the aforementioned substances and pigments (D) without dissolving them, it may also be referred to as a "dispersion medium."

[0060] Examples of alcohol-based solvents include methanol, ethanol, isopropanol, 1-butanol, tertiary butanol, isobutanol, diacetone alcohol, and 3-methoxy-3-methyl-1-butanol. Examples of ketone-based solvents include acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, and diisobutyl ketone. Examples of ester solvents include ethyl acetate, methyl acetate, butyl acetate, methoxybutyl acetate, cellosolve acetate, amyl acetate, n-propyl acetate, isopropyl acetate, methyl lactate, ethyl lactate, and butyl lactate. Examples of ether-based solvents include dibutyl ether, tetrahydrofuran, and dioxane. Examples of glycol ether solvents include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, and butyl cellosolve (ethylene glycol monobutyl ether). Examples of aliphatic hydrocarbon solvents include n-pentane, cyclopentane, methylcyclopentane, n-hexane, isohexane, n-heptane, n-octane, cyclohexane, methylcyclohexane, and ethylcyclohexane. Examples of carbonate-based solvents include propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate. Other examples include various petroleum-based solvents known in the paint industry.

[0061] Furthermore, from the viewpoint of aiming to reduce VOC emissions, it is preferable that the amount of solvent (S) blended in the paint composition of this embodiment is limited. That is, the paint composition of this embodiment has a solid content concentration of 70% by mass or more, preferably 75% by mass or more, more preferably 80% by mass or more, and even more preferably 85% by mass or more. The amount of solvent (S) blended in the paint composition of this embodiment is set to satisfy the above solid content concentration. [Other additives] The paint composition of this embodiment may contain additive components (surface modifiers) that have the effect of improving the smoothness of the paint film surface. Surface modifiers include plasticizers, silicone compounds, waxes, defoamers, leveling agents, and anti-bubble agents (components that break air trapped during painting), which are known in the paint field.

[0062] Examples of surface modifiers include the Acronal® series (BASF, meth)acrylic resin-based, such as Acronal 4F, the Polyflow series (Kyoeisha Chemical Co., Ltd.), the Regiflow series (ESTRON CHEMICAL), the Modaflow series (Monsanto), and benzoin.

[0063] The coating composition of this embodiment may contain only one surface modifier or two or more surface modifiers. Furthermore, the amount of surface modifier in the coating composition of this embodiment is not particularly limited and can be adjusted as appropriate in consideration of other performance characteristics.

[0064] Furthermore, as other optional agents, the coating composition of this embodiment may also contain fillers, ultraviolet absorbers, light stabilizers, antioxidants, magnetic powders, and charge control agents. The amounts of these agents in the coating composition of this embodiment are not particularly limited and can be adjusted as appropriate in consideration of other performance characteristics.

[0065] [Method for manufacturing paint composition] The paint composition of this embodiment is typically prepared by mixing the various components described above. Other materials may also be included in this mixture, and the details of each component are as shown above.

[0066] [Application] The paint composition of this embodiment is used by being applied to a substrate by various coating methods. The applied paint composition then hardens to form a coating film (cured coating film). In other words, the paint composition of this embodiment can form a coating film by hardening after application, and the coated object of this embodiment can be said to comprise a substrate and a coating film provided on the surface of the substrate. The coating method of the paint composition can be set as appropriate, but may include, for example, roll coating, curtain flow coating, spray coating, electrostatic coating, bell coating, dipping, roller coating, brush coating, etc. The substrate constituting the coated object can also be set as appropriate and may be made of materials such as metal, plastic, ceramic, or concrete.

[0067] [Two-component paint composition] Furthermore, in relation to the paint composition described above, this embodiment provides a two-component paint composition. The two-component paint composition here is a two-component paint composition having a first liquid and a second liquid, and the aforementioned paint composition is obtained by mixing the first liquid and the second liquid. Specifically, the first liquid contains a compound (A) containing an active hydrogen group, and the second liquid contains a polyisocyanate compound (B), and by combining these, the various requirements of the aforementioned paint composition are satisfied. In such a two-component paint composition, the first liquid and the second liquid are separated so that they can be mixed as needed, which can contribute to improving the pot life of the paint composition.

[0068] Furthermore, they may be provided in the following embodiments.

[0069] (1) A paint composition having a solid content concentration of 70% by mass or more, comprising a compound (A) containing an active hydrogen group and a polyisocyanate compound (B), wherein the compound (A) containing an active hydrogen group comprises a polyaspartate ester (A1) and a resin (A2) having a hydroxyl group in its side chain, and the weight-average molecular weight of the resin (A2) having a hydroxyl group in its side chain is in the range of 2500 to 20000.

[0070] (2) In the paint composition described in (1) above, the resin (A2) having a hydroxyl group in the side chain comprises a (meth)acrylic polyol.

[0071] (3) A paint composition according to (1) or (2) above, wherein when the content of the polyaspartate ester (A1) is 100 parts by mass, the content of the resin (A2) having a hydroxyl group in its side chain is 20 parts by mass or more.

[0072] (4) A paint composition according to any one of (1) to (3) above, wherein the hydroxyl value of the resin (A2) having hydroxyl groups in the side chain is in the range of 40 mg KOH / g or more and 200 mg KOH / g or less.

[0073] (5) A paint composition according to any one of (1) to (4) above, wherein the polyisocyanate compound (B) comprises an unblocked polyisocyanate compound.

[0074] (6) A paint composition according to any one of (1) to (5) above, further comprising a silane coupling agent (C1) and / or an alkoxysilicate polymer (C2).

[0075] (7) A two-component paint composition comprising a first liquid and a second liquid, wherein mixing the first liquid and the second liquid yields the paint composition according to any one of (1) to (6) above, wherein the first liquid comprises a compound (A) containing the active hydrogen group, and the second liquid comprises the polyisocyanate compound (B).

[0076] (8) A coating film obtained by curing a coating composition described in any one of (1) to (6) above.

[0077] (9) A painted product comprising a base material and a coating film as described in (8) above provided on the surface of the base material. Of course, this is not always the case.

[0078] Although embodiments of the present invention have been described above, these are merely examples, and various other configurations can be adopted. Furthermore, the present invention is not limited to the embodiments described above, and modifications, improvements, etc., within the scope that can achieve the objectives of the present invention are included in the present invention. [Examples]

[0079] The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention is not limited to the following examples.

[0080] [Raw materials used] First, the raw materials used in this embodiment will be described. The various raw materials used in this embodiment are as follows. Tables 1 and 2, shown later, show the solid content concentration for each raw material.

[0081] • A1-1: Desmofen (registered trademark) NH1420 (amine value: 201, viscosity: 1400 mPa·s, manufactured by Covestro) A1-2: Desmofen (registered trademark) NH1520 (amine value: 191, viscosity: 1900 mPa·s, manufactured by Covestro) ·A2-1: Resin obtained by the following synthesis example 1 ·A2-2: Resin obtained by the following synthesis example 2 A2-3: Resin obtained by the following synthesis example 3 • A2-4: Resin obtained by the following synthesis example 4 • A2-5: Resin obtained by the following synthesis example 5 A2-6: Resin obtained by the following synthesis example 6 • B1: Duranate® TKA-100 (manufactured by Asahi Kasei Corporation) • B2: Death Module (registered trademark) N3900 (manufactured by Covestro) • B3: Stavio (registered trademark) D-376N (manufactured by Mitsui Chemicals, Inc.) • B4: Takenate (registered trademark) D-178NL (manufactured by Mitsui Chemicals, Inc.) • B5: Death Module (Registered Trademark) Z4470BA (Manufactured by Covestro) ·C1-1:γ-Glycidoxypropyltrimethoxysilane • C2-1: MKC Silicate MS56 (manufactured by Mitsubishi Chemical Corporation) D1: Titanium Oxide • S1: Butyl acetate • S2: Urethane thinner (manufactured by Natco Co., Ltd.)

[0082] The following are the synthesis formulations for resins A2-1 to A2-6. In the following synthesis examples, "MMA" refers to "methyl methacrylate," "BMA" refers to "butyl methacrylate," "BA" refers to "butyl acrylate," "HEMA" refers to "hydroxyethyl methacrylate," and "MAA" refers to "methacrylic acid."

[0083] <Synthesis Example 1> In an acrylic resin reactor equipped with a stirrer, thermometer, reflux condenser, and dropping funnel, 20 parts butyl acetate and 5 parts 2-mercaptoethanol were charged and heated to 110°C while blowing in nitrogen gas. After reaching 110°C, while stirring, a mixture of 41.5 parts MMA, 20 parts BMA, 18 parts BA, 20 parts HEMA, 0.5 parts MAA, and 10 parts 2,2'-azobis-2-methylbutyronitrile was continuously added dropwise over 2 hours while maintaining the temperature at 100°C. After the dropwise addition was complete, the temperature was maintained at 110°C for 1 hour, and then an additional catalyst solution, a mixture of 0.5 parts 2,2'-azobis-2-methylbutyronitrile and 3 parts butyl acetate, was added, and stirring was continued for a further 3 hours while maintaining the temperature at 110°C. After the reaction was complete, the mixture was cooled to obtain acrylic resin solution (A2-1). The obtained acrylic resin polymer had a weight-average molecular weight (Mw) of 3100 and a hydroxyl value of 86 mgKOH / g.

[0084] <Synthesis Example 2> In an acrylic resin reaction apparatus equipped with a stirrer, thermometer, reflux condenser, and dropping funnel, 20 parts of butyl acetate were charged and heated to 100°C while blowing in nitrogen gas. After reaching 100°C, while stirring, a mixture of 41.5 parts MMA, 20 parts BMA, 18 parts BA, 20 parts HEMA, 0.5 parts MAA, and 8 parts 2,2'-azobis-2-methylbutyronitrile dissolved in 10 parts butyl acetate was continuously added dropwise over 2 hours while maintaining the temperature at 100°C. After the dropwise addition was complete, the temperature was maintained at 100°C for 1 hour, and then an additional catalyst solution, a mixture of 0.5 parts 2,2'-azobis-2-methylbutyronitrile and 3 parts butyl acetate, was added, and stirring was continued for a further 3 hours while maintaining the temperature at 100°C. After the reaction was complete, the mixture was cooled to obtain acrylic resin solution (A2-2). The obtained acrylic resin polymer had a weight-average molecular weight (Mw) of 6400 and a hydroxyl value of 86 mgKOH / g.

[0085] <Synthesis Example 3> In an acrylic resin reactor equipped with a stirrer, thermometer, reflux condenser, and dropping funnel, 20 parts of butyl acetate were charged and heated to 100°C while blowing in nitrogen gas. After reaching 100°C, while stirring, a mixture of 41.5 parts MMA, 20 parts BMA, 18 parts BA, 20 parts HEMA, 0.5 parts MAA, and 2 parts 1,1'-azobis(cyclohexane-1-carbonitride) dissolved in 10 parts butyl acetate was continuously added dropwise over 2 hours while maintaining the temperature at 100°C. After the dropwise addition was complete, the temperature was maintained at 100°C for 1 hour, and then an additional catalyst solution, a mixture of 0.5 parts 1,1'-azobis(cyclohexane-1-carbonitride) and 3 parts butyl acetate, was added, and stirring was continued for a further 3 hours while maintaining the temperature at 100°C. After the reaction was complete, the mixture was cooled to obtain acrylic resin solution (A2-3). The weight-average molecular weight (Mw) of the obtained acrylic resin polymer was 18,500, and the hydroxyl value was 86 mgKOH / g.

[0086] <Synthesis Example 4> In an acrylic resin reaction apparatus equipped with a stirrer, thermometer, reflux condenser, and dropping funnel, 20 parts butyl acetate and 10 parts 2-mercaptoethanol were charged and heated to 110°C while blowing in nitrogen gas. After reaching 110°C, while stirring, a mixture of 41.5 parts MMA, 20 parts BMA, 18 parts BA, 20 parts HEMA, 0.5 parts MAA, and 10 parts butyl acetate in which 18 parts 2,2'-azobis-2-methylbutyronitrile was dissolved was continuously added dropwise over 2 hours while maintaining the temperature at 100°C. After the dropwise addition was complete, the temperature was maintained at 110°C for 1 hour, and then an additional catalyst solution, a mixture of 0.5 parts 2,2'-azobis-2-methylbutyronitrile and 3 parts butyl acetate, was added, and stirring was continued for a further 3 hours while maintaining the temperature at 110°C. After the reaction was complete, the mixture was cooled to obtain acrylic resin solution (A2-4). The weight-average molecular weight (Mw) of the obtained acrylic resin polymer was 1100, and the hydroxyl value was 86 mgKOH / g.

[0087] <Synthesis Example 5> In an acrylic resin reactor equipped with a stirrer, thermometer, reflux condenser, and dropping funnel, 20 parts butyl acetate and 7 parts 2-mercaptoethanol were charged and heated to 110°C while blowing in nitrogen gas. After reaching 110°C, while stirring, a mixture of 41.5 parts MMA, 20 parts BMA, 18 parts BA, 20 parts HEMA, 0.5 parts MAA, and 10 parts butyl acetate in which 15 parts 2,2'-azobis-2-methylbutyronitrile was dissolved was continuously added dropwise over 2 hours while maintaining the temperature at 100°C. After the dropwise addition was complete, the temperature was maintained at 110°C for 1 hour, and then an additional catalyst solution, a mixture of 0.5 parts 2,2'-azobis-2-methylbutyronitrile and 3 parts butyl acetate, was added, and stirring was continued for a further 3 hours while maintaining the temperature at 110°C. After the reaction was complete, the mixture was cooled to obtain acrylic resin solution (A2-5). The weight-average molecular weight (Mw) of the obtained acrylic resin polymer was 2200, and the hydroxyl value was 86 mgKOH / g.

[0088] <Synthesis Example 6> In an acrylic resin reaction apparatus equipped with a stirrer, thermometer, reflux condenser, and dropping funnel, 20 parts of butyl acetate were charged and heated to 100°C while blowing in nitrogen gas. After reaching 100°C, while stirring, a mixture of 41.5 parts MMA, 20 parts BMA, 18 parts BA, 20 parts HEMA, 0.5 parts MAA, and 1 part 1,1'-azobis(cyclohexane-1-carbonitride) dissolved in 10 parts butyl acetate was continuously added dropwise over 2 hours while maintaining the temperature at 100°C. After the dropwise addition was complete, the temperature was maintained at 100°C for 1 hour, and then an additional catalyst solution, a mixture of 1.5 parts 1,1'-azobis(cyclohexane-1-carbonitride) and 3 parts butyl acetate, was added, and stirring was continued for a further 3 hours while maintaining the temperature at 100°C. After the reaction was complete, the mixture was cooled to obtain acrylic resin solution (A2-6). The obtained acrylic resin polymer had a weight-average molecular weight (Mw) of 32,000 and a hydroxyl value of 86 mgKOH / g.

[0089] [Preparation and evaluation of paint compositions] The various raw materials described above were mixed according to the formulations shown in Tables 1 and 2 to obtain the paint compositions of the Examples and Comparative Examples. The obtained paint compositions were evaluated for the following items: <suitability for air spray coating>, <smoothness>, <weather resistance>, and <hot water resistance>. The evaluation method is as follows. Tables 1 and 2 also show the solid content concentration, amount of active hydrogen groups, amount of isocyanate groups, ratio of isocyanate groups to active hydrogen groups, ratio of component (A2) to the sum of components (A) and (B), and ratio of component (A2) to component (A1) for each paint composition. Furthermore, Comparative Example 3 did not undergo further evaluation because the test results for <suitability for air spray coating> were unsatisfactory.

[0090] <Evaluation 1: Suitability for airbrush painting> Using an Anest Iwata Corporation gravity-feed spray gun "W-100" (nozzle diameter: 1.3 mm), each paint composition was applied to a commercially available cold-rolled steel sheet (manufactured by TP Giken Co., Ltd., test piece conforming to JIS G 3141: size 70 mm x 150 mm x 0.8 mm, hereinafter referred to as "SPCC-SD sheet") to a film thickness of 50 μm under the following conditions. The paint ejection state from the gun nozzle was observed during this process.

[0091] [Painting conditions] • Spray air pressure: 0.29 MPa • Internal pressure in cap: 0.2 MPa • Distance between the gun and the object to be coated (length of the perpendicular line drawn from the tip of the gun nozzle to the cold-rolled steel sheet): 200 mm ·Temperature: 20℃ • Discharge rate: Adjust to approximately 410 mL / min • Relative humidity: 65%

[0092] Regarding the above-mentioned paint, the paintability was evaluated according to the following criteria. A rating of 3 or higher indicates a level that is perfectly usable in practical applications. 5: The paint has good fluidity and sprays evenly from the gun nozzle. 4. The paint has good fluidity, but occasionally uneven spraying may occur. 3: The paint has good fluidity, but occasional unevenness in spraying is observed. 2: Paint may not spray easily from the gun nozzle, and the spray may be interrupted. 1: Paint does not spray from the gun nozzle, making painting impossible.

[0093] <Evaluation 2: Smoothness> The surface condition of the painted boards obtained by the above painting process was visually observed and evaluated according to the following criteria. A rating of 3 or higher indicates a level that is perfectly usable for practical purposes. 5: No irregularities (roundness) are observed on the surface of the coating film; it is completely smooth. 4: Very slight irregularities (roundness) are observed on the surface of the coating, but there are no problems with smoothness. 3: The coating has some slight unevenness (roundness), and the level of smoothness is slightly lower, but there are no problems. 2: The coating film clearly shows irregularities (roundness), indicating a low level of smoothness. 1: The paint film has significant irregularities (roundness), resulting in a clearly poor appearance.

[0094] <Evaluation 3: Weather resistance> The painted panels obtained by the above painting method were subjected to weathering tests under the following conditions using an accelerated weathering tester in accordance with JIS K 5600-7-7 (xenon lamp method).

[0095] [Weather resistance conditions] Test equipment: Super Xenon Weather Meter SX75 Filter: Inner / Aura = Quartz / #275 (Borosilicate glass) Cycle: Continuous operation Drying time: 102 minutes (63℃, humidity 50%) Wetting time: 18 minutes (28℃, 95% humidity) Irradiation intensity: 60W / m2 Exposure time: 500 hours

[0096] Specifically, the gloss retention rate, defined by the following formula, was measured using a gloss meter (BYK-Gardner GmbH, trade name Micro-Gloss) with the 60° specular gloss retention rate before the test as the baseline. Gloss retention rate (%) = {(60° gloss value after testing) / (60° gloss value before testing)} × 100 The evaluation was based on the following five-point scale. A rating of 3 or higher indicates that there are no practical problems. 5: Gloss retention rate of 75% or more 4: Gloss retention rate 70% or more but less than 75% 3: Gloss retention rate 50% or more but less than 70% 2: Gloss retention rate 30% or more but less than 50% 1: Gloss retention rate less than 30%

[0097] <Rating 4: Hot water resistance> The painted panels obtained by the above painting method were immersed in 40°C hot water for 7 days. After 7 days, the painted panels were removed from the hot water, and the condition of the paint film (whitening, blistering, peeling) was visually inspected immediately after removal. The results were judged according to the following criteria. A rating of 3 or higher indicates that there are no practical problems. 5: No change is observed at all. 4: Slight whitening occurs, but no swelling or peeling is observed. 3: Whitening is observed, but swelling and peeling are not. 2: Significant whitening or swelling / peeling is observed. 1: Significant whitening, swelling, and peeling are observed.

[0098] [Table 1]

[0099] [Table 2]

[0100] As is clear from the results in Tables 1 and 2, this embodiment makes it possible to realize a paint composition that is highly environmentally friendly and has excellent performance in various aspects.

Claims

1. A paint composition, The solid content concentration is 70% by mass or more. The compound comprises a compound (A) containing an active hydrogen group and a polyisocyanate compound (B), The compound (A) containing the active hydrogen group comprises a polyaspartate ester (A1) and a resin (A2) having hydroxyl groups in its side chain. A paint composition in which the weight-average molecular weight of the resin (A2) having hydroxyl groups in its side chains is in the range of 2,500 to 20,000.

2. In the paint composition according to claim 1, The resin (A2) having hydroxyl groups in its side chain is a paint composition containing a (meth)acrylic polyol.

3. In the paint composition according to claim 1, A paint composition in which, when the content of the polyaspartate ester (A1) is 100 parts by mass, the content of the resin (A2) having a hydroxyl group in its side chain is 20 parts by mass or more.

4. In the paint composition according to claim 1, A paint composition wherein the resin (A2) having hydroxyl groups in its side chain has a hydroxyl value in the range of 40 mg KOH / g or more and 200 mg KOH / g or less.

5. In the paint composition according to claim 1, The aforementioned polyisocyanate compound (B) is a paint composition comprising an unblocked polyisocyanate compound.

6. In the paint composition according to claim 1, A paint composition further comprising a silane coupling agent (C1) and / or an alkoxysilicate polymer (C2).

7. A two-component paint composition having a first liquid and a second liquid, Mixing the first liquid and the second liquid provides the paint composition described in any one of claims 1 to 6. A two-component paint composition comprising a first liquid containing a compound (A) containing the active hydrogen group, and a second liquid containing the polyisocyanate compound (B).

8. A coating film, A coating film obtained by curing the coating composition according to any one of claims 1 to 6.

9. Painted items, Substrate and A coated article comprising: a coating film according to claim 8 provided on the surface of the substrate.

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