JP2023144229A - Resin composition, coating composition, and cured product - Google Patents

Abstract

To provide a resin composition capable of obtaining a coating layer having a small content of inorganic particulates and excellent abrasion resistance, hardness, and stain resistance and to provide a resin molded product having excellent abrasion resistance, hardness, and stain resistance.SOLUTION: There is provided a resin composition comprising a polyol (A) and inorganic fine particles (B), wherein the polyol (A) has a glass transition temperature of -40°C or more and 85°C or less, the inorganic fine particles (B) have a reactive functional group and the ratio of the inorganic fine particles (B) is 1 to 100 pts.wt. based on 100 pts.wt. of the polyol (A).SELECTED DRAWING: None

Description

The present invention relates to a resin composition with excellent scratch resistance, a coating composition containing the resin composition, and a cured product of the resin composition.

Paints used for painting exterior building materials, road materials, vehicles including automobiles, aircraft, etc. are required to have excellent coating performance such as scratch resistance, hardness, and stain resistance, as well as excellent coating appearance. There is.

However, it is difficult to simultaneously satisfy the scratch resistance of the coating film and other required coating film performances. That is, although individual or some of these performances can be achieved by modifying the resin components, it is not possible to satisfy all of them at the same time by improving the resin components. For example, flexible resins can be designed to improve scratch resistance, but in this case, performance such as hardness, water resistance, and stain resistance deteriorates.

The use of inorganic fine particles is attracting attention to solve this problem.

For example, Patent Document 1 describes a urethane resin paint using acrylic polyol and polyisocyanate and silica fine particles as a reinforcing material, and a molded article having a coating film thereof.

Further, Patent Document 2 discloses a thermosetting resin composition containing a polyol, a blocked polyisocyanate, and silica modified with a specific silane coupling agent. By modifying silica with a specific silane coupling agent, the scratch resistance and abrasion resistance of the coating film are improved.

Japanese Patent Application Publication No. 2012-21111 Japanese Patent Application Publication No. 2020-132751

However, the urethane resin coating composition described in Patent Document 1 had insufficient scratch resistance and abrasion resistance under conditions of being used outdoors for a long time. In particular, the scratch resistance and abrasion resistance were insufficient when the amount of silica particles was reduced in order to prevent deterioration of appearance such as whitening due to agglomeration of silica particles.

In addition, the thermosetting composition described in Patent Document 2 has an extremely high proportion of silica particles added in the cured coating film, which not only shortens the pot life of the coating due to agglomeration of the silica particles, but also causes whitening and deterioration of the appearance. The problem was that the price of the paint was high because it uses a large amount of silica, which is more expensive than resin.

The present invention aims to solve these problems, and aims to improve the scratch resistance and hardness of paint films even under conditions of long-term use in exterior building materials, road materials, vehicles including automobiles, aircraft, etc. , to provide a resin composition that can maintain various performances such as stain resistance, a coating composition containing the resin composition, a cured product obtained by curing the coating composition, and a coated article coated with the cured product. purpose.

The present invention has the following aspects.
That is, the above object of the present invention can be achieved by the following means [1] to [14].
[1] A resin composition containing a polyol (A) and inorganic fine particles (B), wherein the polyol (A) has a glass transition temperature of -40°C or more and 85°C or less, and the inorganic fine particles (B) are reactive. A resin composition having a functional group, wherein the proportion of the inorganic fine particles (B) is 1 to 100 parts by weight based on 100 parts by weight of the polyol (A).
[2] The resin composition according to [1], wherein the inorganic fine particles (B) are organosilica sol modified with a silane coupling agent.
[3] The reactive functional group of the inorganic fine particles (B) is one or more functional groups selected from the group consisting of an amino group, an isocyanate group, an epoxy group, and a mercapto group according to [1] or [2]. Resin composition.
[4] The resin composition according to any one of [1] to [3], which contains any one of polyisocyanate, melamine resin, epoxy resin, and alkyl silicate as the crosslinking agent (C).
[5] The resin composition according to any one of [1] to [4], wherein the polyol (A) is an acrylic resin, a polyester resin, or a polycarbonate resin.
[6] The solubility parameter of the polyol (A) is 8.1 or more and 12.5 or less [1
] to [5]. The resin composition according to any one of [5].
[7] The resin composition according to any one of [1] to [6], wherein the polyol (A) has a hydroxyl value of 50 or more and 300 or less.
[8] The weight average molecular weight of the polyol (A) is 900 or more and less than 50,000 [1
] to [7]. The resin composition according to any one of [7].
[9] The resin composition according to any one of [1] to [8], wherein the resin composition contains an ultraviolet absorber (D).
[10] The resin composition according to any one of [1] to [9], wherein the ultraviolet absorber (D) is benzotriazole-based or hydroxyphenyltriazine-based.
[11] The resin composition according to any one of [1] to [10], wherein the resin composition contains a light stabilizer (E).
[12] A coating composition comprising the resin composition according to any one of [1] to [11].
[13] A cured product obtained by curing the coating composition according to [12].
[14] A coated article coated with the cured product according to [13].

The resin composition of the present invention can maintain various performances such as scratch resistance, hardness, and stain resistance of the coating film even under conditions of long-term use in exterior building materials, road materials, vehicles including automobiles, aircraft, etc. A molded article having a resin composition and a coating film of the resin composition can be provided.

The present invention will be described in more detail below by citing preferred embodiments of the invention. However, the following description is an example of the embodiment of the present invention, and the present invention will not exceed the gist thereof. It is not limited to the content.
Note that when the expression "~" is used in this specification, it is used as an expression that includes numerical values or physical property values before and after it. Furthermore, in the present invention, when the expression "(meth)acrylic" is used, it means one or both of "acrylic" and "methacrylic". The same applies to "(meth)acrylate", "(meth)acryloyl", etc.
<Resin composition>

The resin composition of the present invention is a resin composition containing a polyol (A) and reactive inorganic fine particles (B), wherein the polyol (A) has a glass transition temperature of -40°C or more and 85°C or less, The resin composition is a resin composition in which the inorganic fine particles (B) have a reactive functional group, and the proportion of the inorganic fine particles (B) is 1 to 100 parts by weight based on 100 parts by weight of the polyol (A).

<Polyol (A)>
The lower limit of the glass transition temperature of the polyol (A) in the resin composition of the present invention is preferably -40
°C, more preferably -20 °C, still more preferably -10 °C, and most preferably 5 °C. The upper limit is preferably 85°C, more preferably 70°C,
More preferably, the temperature is 60°C. If the glass transition temperature is -40°C or higher, the hardness of the coating film will be good. Further, if the temperature is 85° C. or lower, the paint does not gel and is easy to handle.

前記式（１）中の略号は以下を意味する。
Ｗｉ：単量体ｉの質量分率
Ｔｇｉ：単量体ｉの単独重合体のＴｇ（℃）
なお、単独重合体のＴｇは、「ポリマーハンドブック第４版 Ｊｏｈｎ Ｗｉｌｅｙ
＆ Ｓｏｎｓ著」に記載の数値を用いることができる。
「ポリマーハンドブック第４版 Ｊｏｈｎ Ｗｉｌｅｙ ＆ Ｓｏｎｓ著」に記載のな
い単独重合体のＴｇは、ＪＩＳ規格Ｋ－７１２１－１９８７「プラスチックの転移温度測
定方法」に記載の方法で測定した実測値を用いることができる。
本発明の塗料組成物中のポリオール（Ａ） の含有量は、塗膜を形成する成分中の１～
９５ 質量部 であることが好ましい。より好ましくは１０以上８５以下であり、さらに好
ましくは２０以上７５以下である。ポリオール（Ａ） の含有量が１ 質量部 以上であれ
ば耐擦傷性が向上する。また、ポリオール（ Ａ ） の含有量が９５ 質量部 以下であれ
ば、基材への十分な密着性が得られ、塗膜のクラックが生じにくくなる。 In addition, in this specification, "glass transition temperature (Tg)" (unit: degreeC) means the value calculated by Fox's calculation formula shown by following formula (1).

The abbreviations in the formula (1) have the following meanings.
Wi: Mass fraction of monomer i Tgi: Tg of homopolymer of monomer i (°C)
Note that the Tg of a homopolymer is determined from the "Polymer Handbook 4th Edition, John Wiley
&Sons" can be used.
For the Tg of homopolymers not described in "Polymer Handbook 4th Edition by John Wiley &Sons", use the actual value measured by the method described in JIS Standard K-7121-1987 "Method for Measuring Transition Temperature of Plastics". I can do it.
The content of polyol (A) in the coating composition of the present invention is 1 to 1 in the components forming the coating film.
It is preferably 95 parts by mass. More preferably, it is 10 or more and 85 or less, and still more preferably 20 or more and 75 or less. If the content of polyol (A) is 1 part by mass or more, the scratch resistance will be improved. Moreover, if the content of polyol (A) is 95 parts by mass or less, sufficient adhesion to the base material can be obtained, and cracks in the coating film will be less likely to occur.

The solubility parameter of the polyol (A) is preferably 8.1 or more and 12.5 or less. More preferably 8.5 or more and 12.0 or less, still more preferably 9.0 or more and 1
It is 1.5 or less. If the solubility parameter is 8.1 or more, the compatibility with the inorganic fine particles (B) will be good. Moreover, if the solubility parameter is 12.5 or less, water resistance during coating film formation will be good.

The SP value (solubility parameter) is a measure of solubility and is measured as follows. References SUH, CLARKE [J. P. S. A-1, 5, 1671-1681
(1967)]
・Measurement temperature 20℃
- Sample Weigh 0.5 g of resin into a 100 ml beaker, add 10 ml of a good solvent using a whole pipette, and dissolve with a magnetic stirrer.
-Solvent Good solvent: acetone, dioxane Poor solvent: n-hexane, ion-exchanged water - Turbidity point measurement Add the poor solvent dropwise using a 50ml buret, and the point at which turbidity occurs is the amount added.
-Calculation The SP value δ of the resin is given by the following formula.
δ=(V _ml ^1/2 δ _ml +V _mh ^1/2 δ _mh )/(V _ml ^1/2 +V _mh ^1/2
)
V _m =V ₁ V ₂ /(φ ₁ V ₂ +φ ₂ V ₁ )
δ _m =φ ₁ δ ₁ +φ ₂ δ _2
Vi : Molecular volume of solvent (ml/mol)
φ _i : Volume fraction of each solvent at cloudy point δ _i : SP value of solvent ml: Low SP poor solvent mixed system mh: High SP poor solvent mixed system.

Moreover, it is preferable that the mass average molecular weight of the polyol (A) is 900 or more and 50,000 or less. If the mass average molecular weight is 900 or more, the hardness of the coating film will be good. Moreover, if the mass average molecular weight is 50,000 or less, the viscosity of the coating material will be low and handling will be good. The mass average molecular weight is preferably 1,000 or more and 25,000 or less.

The mass average molecular weight is determined by Gel Permeation Chromatography.
The molecular weight in terms of polystyrene by the y method can be measured by the following measuring method.
(GPC measurement conditions)
Column: "TSK-gel superHZM-M", "TSK-gel HZM-M"
”, “TSK-gel HZ2000”
Eluent: THF
Flow rate: 0.35mL/min
Injection volume: 10μL
Column temperature: 40℃
Detector: UV-8020

Further, the hydroxyl value of the polyol (A) is preferably 50 to 300 mg·KOH/g. When the hydroxyl value is 50 mg·KOH/g or more, a preferable crosslinking density as a coating film can be obtained, and the hardness of the coating film will be good. Moreover, if the hydroxyl value is 300 mg·KOH/g or less, the solubility in the resin composition and the flexibility of the coating film when formed into a coating film will be good.

Examples of the polyol (A) include acrylic polyol, polyester polyol,
Polycarbonate polyols and the like can be used. Among these, acrylic polyols are preferred from the viewpoint of scratch resistance of the coating film formed.

The acrylic polyol can be produced, for example, by copolymerizing a hydroxyl group-containing polymerizable unsaturated monomer and other copolymerizable polymerizable unsaturated monomers by a conventional method.

The hydroxyl group-containing polymerizable unsaturated monomer is a compound having one or more hydroxyl groups and one or more polymerizable unsaturated groups in one molecule.

Specifically, as the hydroxyl group-containing polymerizable unsaturated monomer, a monoester of acrylic acid or methacrylic acid and a dihydric alcohol having 2 to 10 carbon atoms is suitable, such as 2-hydroxyethyl (meth)acrylate. , 2-hydroxypropyl (meth)acrylate,
2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol Examples include polymerizable monomers having a hydroxyl group such as mono(meth)acrylate, Plaxel FM (manufactured by Daicel Corporation, caprolactone addition monomer), and Plaxel FA (manufactured by Daicel Corporation, caprolactone addition monomer). . 2-hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate are preferred since the scratch resistance and abrasion resistance of the coating film are good.

Other radically polymerizable unsaturated monomers copolymerizable with the polymerizable unsaturated monomer having one or more hydroxyl groups in one molecule include esters of acrylic acid or methacrylic acid: for example, (meth)acrylic acid; Acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate , lauryl (meth)acrylate,
C1 of acrylic acid or methacrylic acid such as cyclohexyl (meth)acrylate, octyl (meth)acrylate, lauryl (meth)acrylate, and cyclohexyl (meth)acrylate
~18 alkyl or cycloalkyl ester; alkoxyalkyl ester of acrylic acid or methacrylic acid such as methoxybutyl (meth)acrylate, methoxyethyl (meth)acrylate and ethoxybutyl (meth)acrylate; glycidyl acrylate or glycidyl methacrylate and C3 ~18 monocarboxylic acid compounds (e.g., acetic acid, propionic acid, oleic acid, stearic acid, or lauric acid), adducts of Cardura E-10 and unsaturated acids such as acrylic acid, etc., with alkoxysilane groups. Ethylenically unsaturated monomers containing: for example, 1-methacryloxytrimethoxysilane, 1-ethylenically unsaturated carboxylic acids: for example, crotonic acid, itaconic acid, maleic acid, maleic anhydride, fumaric acid, etc., glycydicyl group-containing vinyl Monomers: for example, glycidyl acrylate, glycidyl methacrylate and allylglycidyl ether; amides of acrylic or methacrylic acid; for example, acrylamide, N-methylolacrylamide and N-butoxymethylacrylamide; others: styrene, acrylonitrile and methacrylamide. Examples include nitrile.

<Reactive inorganic fine particles (B)>
The reactive inorganic fine particles (B) of the present invention need to have a functional group capable of reacting with other functional groups on the surface.
In the present invention, since the reactive inorganic fine particles (B) have a functional group capable of reacting with other functional groups on the surface, the scratch resistance of the coating film is improved.

Examples of the functional group include a mercapto group, an isocyanate group, an epoxy group, a hydroxyl group, an amino group, and a carbamoyl group. In view of high reactivity with the polyol (A) or crosslinking agent (C), mercapto groups, isocyanate groups and epoxy groups are particularly preferred, and mercapto groups are more preferred.

The reactive inorganic fine particles (B) can be obtained by, for example, treating the surface of silica particles or organosilica sol, which do not have a functional group capable of reacting with a hydroxyl group or an isocyanate group, with a silane coupling agent having a functional group. It will be done.

As silica particles that do not have functional groups that can react with hydroxyl groups or isocyanate groups on the surface,
For example, methanol-dispersed silica sol (MA-ST, MA-ST-M
), isopropyl alcohol-dispersed silica sol (IPA-ST, IPA-ST-L, IPA
-ST-ZL, IPA-ST-UP), ethylene glycol dispersed silica sol (EG-ST
, EG-ST-L), dimethylacetamide-dispersed silica sol (DMAC-ST, DMAC
-ST-L), xylene/butanol dispersed silica sol (XBA-ST), methyl ethyl ketone dispersed silica sol (MEK-ST, MEK-ST-L, MEK-ST-ZL, MEKS
Commercial products such as T-UP), methyl isobutyl ketone-dispersed silica sol (MIBK-ST), and propylene glycol monomethyl ether acetate-dispersed silica sol (PMA-ST) can be used.

Examples of the silane coupling agent having a functional group capable of reacting with a hydroxyl group or an isocyanate group include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxy Silane compounds having a glycidyl group such as propylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 1-mercaptomethyltrimethoxysilane, 1-mercaptomethylmethyldimethoxysilane, 1-mercaptomethyltriethoxysilane, 1-mercaptomethylmethyldiethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldiethoxysilane, etc. Silane compound having a mercapto group, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, Examples include silane compounds having an amino group such as 3-aminopropyltriethoxysilane, 3-isocyanatepropyltriethoxysilane, and the like.

In addition, commercially available dispersions of the reactive inorganic fine particles (B) include, for example, SIRMEK20WT%-M70 and SIRMEK50WT%-E86 manufactured by CIK Nanotech Co., Ltd.
, SIRMIBK15WT%-M96, SIRMIBK30WT%-S39, MEK-EC-2130Y, MEK-EC-6150P, MEK-EC-7 manufactured by Nissan Chemical Industries, Ltd.
Examples include 150P.
The reactive inorganic fine particles (B) may be used alone or in combination of two or more.

In addition, the upper limit of the average particle diameter of the reactive inorganic fine particles (B) is determined from the viewpoint of transparency of the coating film.
The thickness is preferably 300 nm or less, more preferably 100 nm or less, even more preferably 50 nm or less. The lower limit of the average particle diameter is preferably 2 nm or more, and 4 nm or more, from the viewpoint of improving scratch resistance.
The above is more preferable.
Note that the average particle diameter is a value converted from a specific surface area measurement value (according to JIS Z8830) by BET adsorption method.

Furthermore, the content of the reactive inorganic fine particles (B) in the resin composition of the present invention is preferably 1 to 100 parts by mass, more preferably 2 to 50 parts by mass, and 5 to 50 parts by mass, based on 100 parts by mass of the polyol (A). ~20 parts by mass is more preferred. By using the content of the reactive inorganic fine particles (B) within the above range, it is possible to maintain scratch resistance and a high appearance for a long period of time, and to reduce costs.

<Crosslinking agent (C)>
A crosslinking agent (C) can be added to the resin composition of the present invention for the purpose of forming a coating film that is tougher and has excellent scratch resistance, chemical resistance, and weather resistance. Examples of the crosslinking agent (C) include polyisocyanates, melamine resins, epoxy resins, alkyl silicates, etc. Polyisocyanates and melamine resins that are highly reactive with polyols (A) and inorganic fine particles (B) are particularly preferred, and have a curing temperature of More preferred are polyisocyanates that can be used for a short time at low temperatures. Further, these crosslinking agents may be used alone or in combination of two or more.

<Polyisocyanate>
The polyisocyanate is preferably a bifunctional or more functional isocyanate compound. As the isocyanate compound, known ones can be used.

Examples of the difunctional isocyanate compound include hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane 4,4-dicyclohexyl diisocyanate, and the like.

The trifunctional or higher functional isocyanate compound is synthesized using the above-mentioned diisocyanate compound as a starting material, and includes a buret compound, a trimethylolpropane adduct compound, an isocyanurate compound, an allophanate compound, and the like. From the viewpoint of increasing the crosslinking density of the coating film and improving the water resistance of the coating film, a trifunctional or higher functional isocyanate compound is preferable.

Examples of trifunctional or higher functional isocyanate compounds include, for example, hexamethylene diisocyanate burette manufactured by Asahi Kasei Co., Ltd.: Duranate 24A-100, hexamethylene diisocyanate adduct: Duranate P-301-75E, and hexamethylene diisocyanate isocyanurate: Duranate TPA. -100, block type isocyanate:
Duranate MF-K60X and trimethylolpropane adduct of 1,3-bis(isocyanatomethyl)cyclohexane manufactured by Mitsui Chemicals: Takenate D-120N, 1,3-
Isocyanurate of bis(isocyanatomethyl)cyclohexane: Takenate D-12
7N, trimethylolpropane adduct of isophorone diisocyanate: Takenate D
-140N, and allophanate hexamethylene diisocyanate: Desmodur XP2679 manufactured by Sumika Bayer Urethane.

Further, as the polyisocyanate, it is also possible to use a blocked polyisocyanate compound, which is a compound obtained by blocking the isocyanate groups in the above polyisocyanate and its derivatives with a blocking agent.

Examples of the blocking agent include phenolics such as phenol, cresol, xylenol, nitrophenol, ethylphenol, hydroxydiphenyl, butylphenol, isopropylphenol, nonylphenol, octylphenol, and methyl hydroxybenzoate; ε-caprolactam, δ-valerolactam, Lactams such as γ-butyrolactam and β-propiolactam; aliphatic alcohols such as methanol, ethanol, propyl alcohol, butyl alcohol, amyl alcohol, lauryl alcohol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono Ethers such as butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, methoxymethanol; benzyl alcohol, glycolic acid, methyl glycolate, ethyl glycolate, butyl glycolate, lactic acid, methyl lactate, ethyl lactate, lactic acid Alcohols such as butyl, methylol urea, methylol melamine, diacetone alcohol, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate; formamide oxime, acetamid oxime, acetoxime, methyl ethyl ketoxime, diacetyl monoxime, benzophenone oxime, cyclohexane oxime, etc. Oxime series; active methylene series such as dimethyl malonate, diethyl malonate, ethyl acetoacetate, methyl acetoacetate, acetylacetone; butyl mercaptan, t-butyl mercaptan, hexyl mercaptan, t-dodecyl mercaptan, 2-mercaptobenzothiazole, thio Mercaptans such as phenol, methylthiophenol, and ethylthiophenol; acetanilide,
Acetanisidide, acetotoluide, acrylamide, methacrylamide, acetamide,
Acid amide systems such as stearic acid amide and benzamide; succinimide, phthalic acid imide,
Imide series such as maleic acid imide; Amine series such as diphenylamine, phenylnaphthylamine, xylidine, N-phenylxylidine, carbazole, aniline, naphthylamine, butylamine, dibutylamine, butylphenylamine; Imidazole series such as imidazole and 2-ethylimidazole ; Urea types such as urea, thiourea, ethylene urea, ethylene thiourea, and diphenyl urea; Carbamate ester types such as phenyl N-phenylcarbamate; Imine types such as ethylene imine and propylene imine; Sodium bisulfite, potassium bisulfite, etc. Examples include sulfite-based and azole-based compounds. Examples of the azole compounds include pyrazole, 3,5-dimethylpyrazole, 3-methylpyrazole, 4-benzyl-3,5
-dimethylpyrazole, 4-nitro-3,5-dimethylpyrazole, 4-bromo-3,5
- Pyrazole or pyrazole derivatives such as dimethylpyrazole, 3-methyl-5-phenylpyrazole; imidazole or imidazole derivatives such as imidazole, benzimidazole, 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole; 2-methylimidazoline, Examples include imidazoline derivatives such as 2-phenylimidazoline.

When blocking (reacting the blocking agent), a solvent can be added as necessary. The solvent used in the blocking reaction is preferably one that is not reactive with isocyanate groups, such as acetone, ketones such as methyl ethyl ketone, esters such as ethyl acetate, and N-methyl-2-pyrrolidone (NMP). Examples include solvents such as:
These isocyanate compounds may be used alone or in combination of two or more.

The blending ratio of the polyisocyanate and polyol (A) is determined from the viewpoint of the performance of the cured film.
O/OH [number of moles of isocyanate groups in polyisocyanate/number of moles of hydroxyl groups in polyol (A)] is preferably blended so that it is 0.5 or more and 2.0 or less, and 0.7
It is more preferably 1.8 or less, and even more preferably 0.8 or more and 1.5 or less.

If the equivalent ratio of isocyanate groups possessed by the polyisocyanate is equal to or higher than the lower limit value, the curing speed of the resin composition can be made faster, and the crosslinking density of the cured film of the resin composition becomes high, so that the curing The hardness and water resistance of the film can be easily improved. If the equivalent ratio of isocyanate groups in the polyisocyanate is below the upper limit, drying properties and adhesion after forming a cured film of the resin composition are likely to be improved.

<Melamine resin>
The melamine resins are resins obtained by addition condensation of amine compounds such as melamine, guanamine, and urea with formaldehyde, or by further addition condensation of such resins with alcohols. For example, the resin is methylated melamine, butylated melamine, methylated benzoguanamine, butylated benzoguanamine, and the like. Particularly preferred are fully or partially methylolated melamine resins, such as hexamethylolmelamine, pentamethylolmelamine, tetramethylolmelamine, etc., and mixtures thereof.

Specifically, CYMEL 303 (manufactured by Cytec), CYMEL 325 (manufactured by Cytec)
), CYMEL 1156 (manufactured by Cytec), YUBAN 20N (manufactured by Mitsui Toatsu Chemical Co., Ltd.), YUBAN 20SB (manufactured by Mitsui Toatsu Chemical Co., Ltd.), YUBAN 128 (manufactured by Mitsui Toatsu Chemical Co., Ltd.), SUMIMAL M -50W (manufactured by Sumitomo Chemical Co., Ltd.), SUM
Examples include IMAL M-40N (manufactured by Sumitomo Chemical Co., Ltd.) and SUMIMA L M-30W (manufactured by Sumitomo Chemical Co., Ltd.). Each of these melamine resins may be used alone,
A mixture of two or more types may be used.

<Epoxy resin>
The epoxy resin is an epoxy compound or an epoxy resin, and in addition to conventionally known ones, any one having an average of two or more glycidyl groups (epoxy groups) in the molecule can be used without any restriction.

Examples of the epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, novolak epoxy resin such as phenol novolac epoxy resin and cresol novolac epoxy resin, alicyclic epoxy resin, 3',4'- Cyclic alicyclic epoxy resins such as epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, triglycidyl isocyanurate, nitrogen-containing cyclic epoxy resins such as hydantoin type epoxy resins, hydrogenated bisphenol A type epoxy resins, aliphatic type epoxy resins, etc. Examples include epoxy resins, glycidyl ether type epoxy resins, bisphenol S type epoxy resins, biphenyl type epoxy resins, dicyclocyclic epoxy resins, naphthalene type epoxy resins, and halogenated epoxy resins. These epoxy resins may be used alone or in combination of two or more.

Furthermore, the content of the crosslinking agent (C) in the resin composition of the present invention is as follows:
00 parts by mass, preferably 5 to 100 parts by mass, more preferably 10 to 80 parts by mass,
More preferably 20 to 60 parts by mass. By using the content of the crosslinking agent (C) within the above range, drying properties and adhesion after forming a cured film of the resin composition are likely to be improved.

<Weather resistance imparting material>
Furthermore, in order to impart weather resistance to the coating film, the resin composition of the present invention includes an ultraviolet absorber (D),
It may also contain a weather resistance imparting agent such as a light stabilizer (E).

The ultraviolet absorber (D) is preferably a compound derived from triazine, benzophenone, benzotriazole, phenyl salicylate, phenyl benzoate, etc., and can be contained in a large amount in the resin composition. Benzophenone-based compounds are preferred, and triazine- and benzotriazole-based compounds are preferred because they can prevent yellowing of base materials such as polycarbonate.
Furthermore, it is more preferable that the maximum absorption wavelength of the ultraviolet absorber (D) is in the range of 240 to 380 nm.

Specific examples of the ultraviolet absorber (D) include 2-[4-(2-hydroxy-3-dodecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl) -1,3,5-triazine] and 2-[4-(2-hydroxy-3-tridecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1 , 3,5-triazine] {trade name ``Tinuvin 400'' (BA
SF)}, 2-[4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)]-1,3,5-triazine{
Product name: "Tinuvin 479" (BASF)}, Tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5- Triazine] {Product name: "Tinuvin 777" (BASF)}, 2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4 -Octyloxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4
-Octadesiloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, phenyl salicylate, p-tert-butylphenyl salicylate, p-(1,1 , 3,3-tetramethylbutyl)phenyl salicylate, 3-hydroxyphenylbenzoate, phenylene-1,3-dibenzoate, 2-(2-hydroxy-5'-methylphenyl)benzotriazole, 2-(2-hydroxy- 5-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)benzo Triazole, 2-(2-hydroxy-4-octylphenyl)benzotriazole and 2-(2
Examples include '-hydroxy-5'-methacryloxyethylphenyl)-2H-benzotriazole. These may be used alone or in combination of two or more.

The content of the ultraviolet absorber (D) in the resin composition of the present invention includes polyol (A),
0.1 to 4 based on the total mass (100 parts by mass) of reactive inorganic fine particles (B) and crosslinking agent (C)
0 part by weight is preferable, and 0.5 to 30 parts by weight is more preferable. When the content of the ultraviolet absorber (D) is 0.1 parts by mass or more, the weather resistance of the coating film tends to improve. Also, the content is 40
When the amount is less than 1 part by mass, the curability of the resin composition, the hardness of the coating film, and the scratch resistance tend to improve.

As the light stabilizer (E), for example, a hindered amine light stabilizer can be used. When used together with a UV absorber, a hindered amine light stabilizer can further improve the weather resistance of the cured film.

Specific examples of the light stabilizer (E) include hindered amine light stabilizers such as A
1,2,3,4-butanetetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinol and β,β,β,β-tetramethyl-3,9-(2 ,4,8,
10-Tetraoxaspiro[5,5]) undecane) condensate with diethanol (trade name:
Adekastab (registered trademark. The same applies hereinafter) LA-63P), 1,2,3,4-butanetetracarboxylic acid and 2,2,6,6-pentamethyl-4-piperidinol and β,β,β,β-tetra Condensate with methyl-3,9-(2,4,8,10-tetraoxaspiro[5,5])undecane)diethanol (trade name: Adekastab LA-68P), 1 manufactured by BASF,
Condensation product of 1-dimethylethyl hydroperoxide and octane, bis(2,2
,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) ester, 1,
Reaction products of 1-dimethylethyl hydroperoxide and octane (for example, Tinuvin (trade name; the same applies hereinafter) 123), 2-butyl-2-[3,5-di(tert-butyl)-4
-hydroxybenzyl] malonate bis(1,2,2,6,6-pentamethyl-4-piperidyl) (trade name: Tinuvin 144), 2,4-bis[N-butyl-N-(1-cyclohexyloxy-) 2,2,6,6-tetramethylpiperidin-4-yl)amino]-6-(2-
Hydroxyethylamine)-1,3,5-triazine (trade name: Tinuvin 152), bis(1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate and methyl sebacate (1,2, 2,6,6-pentamethylpiperidin-4-yl) (trade name:
Tinuvin 292) and the like.
The hindered amine light stabilizers may be used alone or in combination of two or more.

The content of the light stabilizer (E) in the resin composition of the present invention is 0.00% relative to the total mass (100 parts by mass) of the polyol (A), the reactive inorganic particles (B), and the crosslinking agent (C). It is preferably 1 part by mass or more and 10 parts by mass or less, more preferably 0.5 parts by mass or more and 5 parts by mass or less.
When the content of the light stabilizer (E) is at least the above lower limit, the weather resistance of the coating film is likely to improve. If the content of the light stabilizer (E) is below the above upper limit, the curability of the composition, the hardness of the cured film, and the scratch resistance are likely to improve.

<Method for manufacturing resin composition>
Next, an example of a method for producing the resin composition of the present invention will be described.
The resin composition of the present invention can be produced by uniformly mixing polyol (A) and reactive inorganic fine particles (B). Note that the other components mentioned above may be added if necessary.

<Other ingredients>
The resin composition of the present invention may optionally include a crosslinking agent (C), a curing accelerating catalyst, an organic solvent, an antioxidant, an anti-yellowing agent, a bluing agent, a pigment, a leveling agent, an antifoaming agent, a A sticky agent, an antisettling agent, an antistatic agent, an antifogging agent, etc. may be added.

<Curing accelerating catalyst>
The resin composition of the present invention can be cured at room temperature or by heating, and may contain a curing accelerating catalyst if necessary.
The resin composition of the present invention optionally contains triethylamine, tetra(2-ethylhexyl) titanate, di-n-butyltin dilaurate, and 1,4-diazabicyclo[2.2.
2] It may contain a curing accelerating catalyst such as octane.

<Organic solvent>
The resin composition of the present invention may contain an organic solvent.
Examples of the organic solvent include methanol, isopropyl alcohol, n-butanol, diacetone alcohol, 2-methoxyethanol (methyl cellosolve), 2-ethoxyethanol (ethyl cellosolve), 2-butoxyethanol (butyl cellosolve), and tertiary amyl alcohol. Alcohol solvents; carboxylic acid ester solvents such as ethyl acetate, n-propyl acetate, butyl acetate and butyl formate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, acetone and cyclohexanone; amide solvents such as dimethylformamide and dimethylacetamide ; diethyl ether, methoxytoluene, 1,2-
Ether solvents such as dimethoxyethane, 1,2-dibutoxyethane, 1,1-dimethoxymethane, 1,1-dimethoxyethane, 1,4-dioxane and tetrahydrofuran; aliphatic solvents such as hexane, pentanxylene, toluene and benzene and aromatic hydrocarbon solvents. These may be used alone or in combination of two or more.

<Coating composition>
The coating composition of the present invention contains the resin composition of the present invention. If necessary, add a curing accelerating catalyst, an organic solvent, an antioxidant, an anti-yellowing agent, a bluing agent, a pigment, a leveling agent, an antifoaming agent, a thickener, an antisettling agent, an antistatic agent, and an antifogging agent. agents, etc. are blended into the resin composition of the present invention.

<Cured product>
A cured product can be obtained by curing the resin composition or coating composition of the present invention with heat.

The temperature at which the resin composition of the present invention is cured may be appropriately set in consideration of the heat resistance and thermal deformability of the base material, but preferably 20°C or more and 200°C or less, more preferably 60°C or more and 150°C or less. preferable. The curing time is preferably several minutes to several hours.

<Painted object>
A coated article having a coating film made of a cured product of the resin composition of the present invention can be obtained by coating a substrate with the coating composition using a known coating method.

Base materials include metals such as galvanized steel plates, zinc alloy plated steel plates, stainless steel plates, and tin-plated steel plates, polymethyl methacrylate resin, polycarbonate resin, polyester resin, polystyrene resin, ABS resin, AS resin, polyamide resin, and polyarylate. resins, polymethacrylimide resins, polyallyl diglycol carbonate resins, and the like. Further, these base materials may be coated with a primer in advance.

The coating film formed from the resin composition of the present invention may be a single layer or at least one layer of a multilayer coating film, and is particularly suitable as the outermost layer of a multilayer coating film. Examples of the multilayer coating include (1) a multilayer coating consisting of a colored base coating and a clear coating, (2) a first colored base coating,
Examples include multilayer coating films consisting of a second colored base coating film and a clear coating film. The coating composition of the present invention is particularly useful as a clear coating for forming a clear coating among these multilayer coatings.

Coating can be performed by known methods such as brush coating, bar coating, spray coating, dip coating, spin coating, and curtain coating.

The thickness of the coating film obtained by curing the resin composition of the present invention is preferably 1 to 50 μm. The thickness is preferably 1 μm or more in order to obtain the effects of the coating composition of the present invention, and 50 μm or more in terms of reducing cracks.
m or less is preferable.

The present invention will be explained in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Note that "parts" and "%" respectively indicate "parts by mass" and "% by mass" unless otherwise specified.

<Evaluation sample>
Each coating composition was applied onto a black coated metal plate to a dry film thickness of 30 to 40 μm, and after pre-drying at room temperature for 5 minutes, it was dried and cured in a dryer at 140°C for 30 minutes. A film was formed and evaluated according to the description in "[Evaluation of Coating Film]" below, and the results are shown in Tables 2 and 3.

[Evaluation of coating film]
(Coating film hardness)
The hardness of the obtained copolymer coating film was measured using an ultra-micro hardness meter (manufactured by Fisher Instruments,
It was measured using the product name (trade name: HM2000). The measurement conditions were F (test force) = 50 mN/10 seconds, C (maximum load creep time) = 10 seconds, and the Martens hardness was measured at five different locations on the same coating film, and the average value was calculated as the average value of the coating film. hardness.
The criteria for determining hardness are as follows.
・Judgment criteria ◎ Hardness is 100N/mm ² or more 〇 Hardness is 50N/mm ² or more △ Hardness is 35N/mm ² or more × Hardness is 35N/mm less than ²

(Initial gloss of paint film)
The 20° gloss of the obtained coating film was measured using a gloss meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., trade name: VG7000).

(Gloss after scratch test)
Sandpaper (abrasive grains: aluminum oxide, mesh:
2000) was pressed against it, and it was made to reciprocate 10 times at a load of 150 gf/cm ² using a Gakushin friction tester. The 20° gloss of the coating film after being scratched back and forth was measured and defined as the gloss after the scratch test.

(scratch resistance)
Scratch resistance was determined by dividing the gloss value after the paint film scratch test by the initial gloss value.
The criteria for evaluating scratch resistance are as follows.
・Judgment criteria◎ Scratch resistance is 90% or more 〇 Scratch resistance is 80% or more × Scratch resistance is less than 80%

(Appearance of paint film)
The appearance of the coating film was visually observed and evaluated using the following criteria.
・Judgment criteria〇 No abnormality.
× There is whitening or spots on the paint film appearance.

(Water resistance of paint)
The water resistance of the coating film was evaluated by immersing the evaluation sample in 70° C. warm water and visually observing the appearance of the coating film after allowing it to stand for 24 hours.
・Judgment criteria〇 No abnormality.
× There is whitening or cracks on the paint film appearance.

(Weather resistance of paint)
The test piece was used as an accelerated weather resistance test QUV (manufactured by Suga Test Instruments Co., Ltd., product name: Dew Panel Control Weather Meter (FDP)), and light irradiation was performed using simulated sunlight at an illuminance of 30.
W/m2, 4 hours at 60℃, 4 hours at 50℃ with condensation, a total of 8 hours, and this is 7 hours.
Repeat for 20 hours. ).
Then, using a gloss meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., product name: VG7000), measure the reflectance (20° gloss) of light incident at an angle of 20° from the vertical direction of the coating surface after the test. Then, the gloss retention rate (%) with respect to the 20° gloss value of the coating film before the weather resistance test was calculated.
In addition, using a spectrophotometer (manufactured by Konica Minolta, product name: CM-5), C light source, angle 2
The absolute value of the color difference (ΔE) of the coating film before and after the weather resistance test was measured at 10°C. Based on these values, the weather resistance of the coating film was evaluated according to the following evaluation criteria.
- Judgment Criteria: Gloss retention was 90% or more and ΔE was less than 3.0.
× Gloss retention was less than 90%, or ΔE was 3.0 or more.

<Production of polyol compound (A)>
・Production example 1 (polyol (A-1))
55.7 parts of propylene glycol monomethyl ether acetate was added as an initial solvent to a four-necked flask equipped with a stirrer, a thermometer, a cooling tube, and a nitrogen gas inlet, and the mixture was heated to an internal temperature of 140°C under nitrogen gas ventilation. Heated. After the internal temperature stabilized, 5 parts of styrene, 54.3 parts of 2-ethylhexyl acrylate, 40 parts of hydroxyethyl methacrylate, and 0.0 parts of acrylic acid were added.
A mixture (dropwise preparation) of 7 parts and 6 parts of Perbutyl (registered trademark) O (tert-butyl peroxy 2-ethylhexanoate, manufactured by NOF Corporation) as a polymerization initiator was added dropwise over 4 hours. After the dropwise addition was completed and held for 1 hour, 0.3 parts of Perbutyl (registered trademark) O was dissolved in 13 parts of propylene glycol monomethyl ether acetate and added. After that, 1
After holding for a period of time, the mixture was cooled to room temperature to obtain polyol (A-1). Polyol (A-1)
The weight average molecular weight (Mw) of the copolymer in the polyol (A-1
) of the glass transition temperature (Tg) of the polyol and the hydroxyl value of the polyol calculated from the amount of monomer charged (
OHV), and the measured SP values of polyol (A-1) are shown in the copolymer properties column of Table 1.

・Production Examples 2 to 6 (Polyols (A-2) to (A-6))
Polyols (A-2) to (A-6) having a solid content of 60% were obtained in the same manner as in Production Example 1, except that the monomers shown in Table 1 below were used.

Each abbreviation in Table 1 means the following.
・St: Styrene ・MMA: Methyl methacrylate ・iBMA: Isobutyl methacrylate ・EHA: 2-ethylhexyl acrylate ・HEA: 2-hydroxyethyl acrylate ・HEMA: 2-hydroxyethyl methacrylate ・AA: Acrylic acid

・Production Example 7 (Production method of reactive inorganic fine particles (B-1) having mercapto groups)
3-Mercaptopropyltrimethoxysilane (manufactured by Tokyo Kasei Kogyo Co., Ltd.) 1 in flask A
．． 2g of distilled water, 0.6g of distilled water, and 2.1g of tetrahydrofuran were charged, and the mixture was stirred at 30°C for 3 hours to carry out a hydrolysis reaction. Next, 100 g of methyl isobutyl ketone dispersed silica sol (trade name: "MIBK-ST", manufactured by Nissan Chemical Industries, Ltd., solvent: methyl isobutyl ketone, solid content concentration: 30 parts by mass, average particle size: 15 nm) was placed in flask B. was charged and the temperature was raised to 70°C. The silanol solution from flask A was added dropwise to flask B, and the reaction was carried out for 1 hour after the completion of the addition to obtain a dispersion liquid (B-1) of reactive inorganic fine particles having a mercapto group.

(Example 1)
As polyol (A), polyol (A-1) (hydroxyl value: 172.4 mgKOH/
g, Mw: 6500), 4 parts of the dispersion (B-1) of the above-mentioned reactive inorganic particles having a mercapto group as the reactive inorganic fine particles (B), and Duranate TP as the crosslinking agent (C).
16.6 parts of A-100 (manufactured by Asahi Kasei Corporation, isocyanurate of hexamethylene diisocyanate), Tinuvin 400 (trade name, manufactured by BASF) as an ultraviolet absorber (D)
and 0.55 parts of Tinuvin 152 (trade name, manufactured by BASF) as a light stabilizer (E).
7 parts, and 0.0 parts of silicone leveling agent BYK-333 (manufactured by BYK) as a surface conditioner.
08 parts were mixed uniformly, and the solution was diluted using cyclohexanone as a diluting solvent.
Table 2 shows the evaluation results of the obtained coating composition. Further, the viscosity of the coating composition diluted to have a solid content of 50% at 20°C was determined to be No. 4 The results of evaluation using the Ford Cup are also shown in Table 2.

(Examples 2 to 12 and Comparative Examples 1 to 5)
With the compositions shown in Tables 2 and 3, coating compositions were prepared and evaluated in the same manner as in Example 1.
The evaluation results are shown in Tables 2 and 3.

Each abbreviation in Tables 2 and 3 means the following.
・MEK-ST: MEK dispersed silica sol manufactured by Nissan Chemical Co., Ltd. (average particle size of silica particles: 10~
15nm)

As shown in Table 3, the resin composition of Comparative Example 5 did not contain reactive inorganic fine particles (B) having a reactive functional group on the surface, so the scratch resistance of the cured film was poor. Comparative examples 1 to 4
Since the resin composition did not contain the inorganic fine particles (B), the scratch resistance of the cured film was poor.

Since the resin composition of the present invention has excellent appearance, scratch resistance, hardness, etc., it can be suitably used for coating exterior building materials, road materials, vehicles including automobiles, aircraft, etc.

Claims (14)

A resin composition comprising a polyol (A) and inorganic fine particles (B), the resin composition comprising a polyol (A) and an inorganic fine particle (B).
) has a glass transition temperature of -40°C or more and 85°C or less, the inorganic fine particles (B) have a reactive functional group, and the proportion of the inorganic fine particles (B) is based on 100 parts by weight of the polyol (A). 1 to 100 parts by weight of the resin composition. The resin composition according to claim 1, wherein the inorganic fine particles (B) are organosilica sol modified with a silane coupling agent. The resin composition according to claim 1 or 2, wherein the reactive functional group of the inorganic fine particles (B) is one or more functional groups selected from the group consisting of an amino group, an isocyanate group, an epoxy group, and a mercapto group. The resin composition according to any one of claims 1 to 3, containing any one of polyisocyanate, melamine resin, epoxy resin, and alkyl silicate as the crosslinking agent (C). The resin composition according to any one of claims 1 to 4, wherein the polyol (A) is an acrylic resin, a polyester resin, or a polycarbonate resin. Claim 1: The solubility parameter of the polyol (A) is 8.1 or more and 12.5 or less.
5. The resin composition according to any one of 5 to 5. The resin composition according to any one of claims 1 to 6, wherein the polyol (A) has a hydroxyl value of 50 or more and 300 or less. Claim 1 wherein the weight average molecular weight of the polyol (A) is 900 or more and less than 50,000.
7. The resin composition according to any one of items 7 to 7. The resin composition according to any one of claims 1 to 8, wherein the resin composition contains an ultraviolet absorber (D). The resin composition according to any one of claims 1 to 9, wherein the ultraviolet absorber (D) is benzotriazole-based or hydroxyphenyltriazine-based. The resin composition according to any one of claims 1 to 10, wherein the resin composition contains a light stabilizer (E). A coating composition comprising the resin composition according to any one of claims 1 to 11. A cured product obtained by curing the coating composition according to claim 12. A coated article coated with the cured product according to claim 13.