Coating composition

Abstract

To provide a coating composition that can give a smooth comfortable feel.SOLUTION: A coating composition contains a methacrylic resin having a hydroxy group, a polyisocyanate compound, and particles with an average particle size of 1.0 μm or more and 100.0 μm or less. The methacrylic resin has a polysiloxane skeleton.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a paint composition.

Background Art

[0002] Recently, plastic products that are frequently touched by people, such as automotive interior parts such as instrument panels and center consoles, and parts related to electrical and electronic devices such as computer casings, as well as parts related to daily life and furniture and building materials, are often required to have a smooth and non-sticky touch.

[0003] Patent Document 1 discloses a composition for forming a natural leather topcoat film containing a polyurethane resin or a polyurethane acrylic resin, silica fine particles or polyurethane resin fine particles, an aqueous polyaliphatic isocyanate crosslinking agent, and a silicone-based touch agent. Patent Document 2 discloses a coated metal plate coated with a coating layer having an overcoat layer containing a silicone-acrylic resin compound obtained by graft-polymerizing a polysiloxane chain within a predetermined range of glass transition temperature and number average molecular weight and an isocyanate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Document 1, when a silicone-based tactile agent with strong hydrophobicity is added, due to its poor compatibility with polyurethane resins and polyacrylic resins, it is unevenly incorporated into the coating film, and sufficient smoothness cannot be obtained. In addition, the silicone-based tactile agent may elute (bleed) on the surface of the coating film, which may have an adverse effect on the touch. Further, in Patent Document 2, since the content of the silicone-acrylic resin in the topcoat layer component is small, the content of the polysiloxane chain graft-polymerized is also small, and there is concern that sufficient smoothness cannot be obtained when touched with a finger.

[0006] The present invention has been made in view of such circumstances. An object of the present invention is to provide a coating composition capable of obtaining a smooth and comfortable touch.

Means for Solving the Problems

[0007] The present inventors have intensively studied a coating composition for solving the above problems from various viewpoints. As a result, it has been found that the above problems can be solved by introducing a polysiloxane compound into a (meth)acrylic resin and containing particles in a predetermined range in the coating composition.

[0008] According to the present invention, a (meth)acrylic resin having a hydroxy group, a polyisocyanate compound, particles having an average particle diameter of 1.0 μm or more and 100.0 μm or less, and a coating composition is provided in which the (meth)acrylic resin has a polysiloxane skeleton.

Effects of the Invention

[0009] According to the present invention, a coating composition capable of obtaining a smooth touch when the coating film is touched with a finger is provided.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail.

[0011] In this specification, the notation "X to Y" in the description of a numerical range represents X or more and Y or less, unless otherwise specified. For example, "1 to 5 mass%" means "1 mass% or more and 5 mass% or less".

[0012] In the notation of a group (atomic group) in this specification, a notation that does not indicate whether it is substituted or unsubstituted includes both those having no substituent and those having a substituent. For example, the term "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). The notation "(meth)acrylic" in this specification represents a concept that includes both acrylic and methacrylic. The same applies to similar notations such as "(meth)acrylate".

[0013] <Paint composition> The paint composition of this embodiment comprises a (meth)acrylic resin having a hydroxy group, a polyisocyanate compound, and particles having an average particle diameter of 1.0 μm or more and 100.0 μm or less. The above (meth)acrylic resin has a polysiloxane skeleton.

[0014] The paint composition of this embodiment can provide a paint composition capable of obtaining a smooth touch. The mechanism thereof is not clear in detail, but can be explained as follows. Just to be on the safe side, the scope of the present invention is not limited by the following explanation.

[0015] The paint composition used in this embodiment is a composition containing particles of a predetermined size in a curing system of a (meth)acrylic resin having a hydroxy group and a polysiloxane skeleton and a polyisocyanate compound. ​As an example of a coating composition, an acrylic urethane paint with a high degree of design freedom and excellent workability and coating film physical properties can be mentioned. Further, as an example of imparting a smooth touch to the coating film, there is a method of adding a compound having a polysiloxane skeleton (hereinafter referred to as "polysiloxane compound") to the paint. Generally, the higher the content of the polysiloxane compound in the coating film, the easier it is to obtain a smooth touch. However, since the polysiloxane compound has poor compatibility with the hydroxy group-containing (meth)acrylic resin, which is the main component of the acrylic urethane paint, and the polyisocyanate compound of the curing agent, unreacted substances of the polysiloxane compound tend to remain. When the unreacted substances elute to the surface of the coating film, the coating film develops a sticky feeling and the touch deteriorates. In this embodiment, the polysiloxane compound was added during the synthesis of the (meth)acrylic resin and introduced in a form chemically bonded to the (meth)acrylic resin. By doing so, compared with the case where the polysiloxane compound is added alone (without chemical bonding), the compatibility with the hydroxy group-containing (meth)acrylic resin, etc. is significantly improved, elution due to unreacted substances can be suppressed, and a coating film with a suitable touch can be obtained. Also, when the size of the particles is within an appropriate range, it is considered that a part of the particles moderately protrudes on the surface of the coating film, the contact area when touching with a finger decreases, and a smooth and comfortable touch can be obtained.

[0016] ((meth)acrylic resin) The coating composition in this embodiment contains a (meth)acrylic resin. (meth)acrylic resin means a resin (polymer) containing a structural unit derived from a monomer of (meth)acrylic acid and / or (meth)acrylic acid ester. That is, the (meth)acrylic resin may partially contain a structural unit derived from a monomer that is not (meth)acrylic. However, from the viewpoint of fully obtaining the effects derived from the (meth)acrylic structure, the (meth)acrylic resin preferably has 50% by mass or more (more preferably 80% by mass or more) of all structural units as structural units derived from monomers of (meth)acrylic acid and / or (meth)acrylic acid ester.

[0017] From another perspective, the (meth)acrylic resin may have at least any partial structure selected from the group consisting of polycaprolactone, polycaprolactam, polycarbonate, polyester, and polyether. Since these chemical structures are moderately flexible and elastic, the flexibility and elasticity of the coating film can be enhanced. These partial structures are preferably present in the side chain of the (meth)acrylic resin.

[0018] Also, the (meth)acrylic resin preferably does not contain a fluoroalkyl group. Although the detailed mechanism is not clear, this can more effectively impart a smooth touch to the coating film. In addition, the compatibility between the (meth)acrylic resin and components in other coating compositions such as polyisocyanate compounds can be improved. Furthermore, the dispersibility of the particles in the coating composition can be improved. Therefore, it is considered that a smooth touch can be imparted to the coating film. Also, from the same perspective, the (meth)acrylic resin preferably does not contain fluorine.

[0019] The (meth)acrylic resin in the present embodiment preferably contains, as constituent units, one or more (meth)acrylic monomers selected from the group consisting of the following (i) to (iv) and the polysiloxane compound of (v). As the (meth)acrylic monomer, those represented by the general formula CH2=CR-COO-R' are preferred. Here, R is a hydrogen atom or a methyl group, and R' is a hydrogen atom or a monovalent organic group. The monovalent organic group of R' is preferably an alkyl group, a monocyclic or polycyclic cycloalkyl group, an aryl group, or an aralkyl group, and these groups may further have substituents. Note that two or more (meth)acrylic monomers corresponding to, for example, (i) may be selected.

[0020] (i) In the general formula CH2=CR-COO-R', a monomer in which R' is a monovalent organic group, and the organic group is an alkyl group, a monocyclic or polycyclic cycloalkyl group, an aryl group, or an aralkyl group. Specific examples thereof include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, n-lauryl (meth)acrylate, n-stearyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, and the like. Among these, those having an alkyl group with a small number of carbon atoms in R' have a high glass transition temperature (°C), and those having an alkyl group with a large number of carbon atoms in R' have a low glass transition temperature (°C). Depending on the target glass transition temperature (°C) of the (meth)acrylic resin, monomers having alkyl groups with different numbers of carbon atoms in R' can be used in combination.

[0021] When the (meth)acrylic resin contains a structural unit derived from this monomer, its content is preferably 0.5 to 80% by mass, more preferably 0.7 to 70% by mass, still more preferably 1 to 60% by mass, based on 100% by mass of all the structural units of the (meth)acrylic resin.

[0022] (ii) In the general formula CH2=CR-COO-R', a monomer in which the monovalent organic group of R' is substituted with a polar group such as a hydroxy group. Specific examples thereof include, for example, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and the like. When the (meth)acrylic resin contains a structural unit derived from this monomer, its content is preferably 1 to 40% by mass, more preferably 5 to 30% by mass, based on 100% by mass of all the structural units of the (meth)acrylic resin.

[0023] (iii) In the general formula CH2=CR-COO-R', a monomer in which R' contains at least any partial structure selected from the group consisting of polycaprolactone, polycaprolactam, polycarbonate, polyester, and polyether. Specific examples thereof include the product name "Placcel F" series of Daicel Corporation, methoxypolyethylene glycol mono(meth)acrylate having an ethylene oxide addition mole number of 3 to 20, polypropylene glycol mono(meth)acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, and the like. The resin containing a structural unit derived from the monomer of (iii) above is considered particularly preferable in terms of improving the flexibility of the coating film. When the (meth)acrylic resin contains a structural unit derived from this monomer, its content is preferably 1 to 60% by mass, more preferably 5 to 50% by mass, based on 100% by mass of all the structural units of the (meth)acrylic resin.

[0024] (iv) In the general formula CH2=CR-COO-R', a monomer in which R' is a hydrogen atom. Specific examples thereof include (meth)acrylic acid. When the (meth)acrylic resin contains a structural unit derived from this monomer, its content is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, based on 100% by mass of all the structural units of the (meth)acrylic resin.

[0025] (v) is a polysiloxane compound. By using (v) during the synthesis of the (meth)acrylic resin of this embodiment, a polysiloxane skeleton can be introduced into the (meth)acrylic resin. Details of the polysiloxane compound will be described later together with the method of introduction during the synthesis of the (meth)acrylic resin.

[0026] The (meth)acrylic resin in the coating composition of this embodiment has a hydroxy group. The hydroxy group of the (meth)acrylic resin can react with the isocyanate group of the polyisocyanate compound described later to form a crosslinked structure.

[0027] As a method for quantifying the hydroxy group contained in the (meth)acrylic resin, it is known to use the hydroxyl value. More specifically, the (meth)acrylic resin preferably has a hydroxyl value of 20 mgKOH / g or more, more preferably 30 to 150 mgKOH / g, still more preferably 50 to 120 mgKOH / g, and even more preferably 50 to 115 mgKOH / g. By setting this numerical range, the polyisocyanate compound described later and the (meth)acrylic resin react moderately, and the crosslinked structure is appropriately controlled. Therefore, the glass transition temperature of the coating film can be increased while maintaining the flexibility and elasticity of the coating film. The hydroxyl value is the number of milligrams of potassium hydroxide required to neutralize acetic acid bonded to the hydroxyl group when 1 g of the sample is acetylated. Specifically, it is measured and calculated according to the method specified in "7.1 Neutralization Titration Method" of JIS K 0070 "Test Methods for Acid Value, Saponification Value, Ester Value, Iodine Value, Hydroxyl Value and Unsaponifiable Matter of Chemical Products".

[0028] The (meth)acrylic resin in the coating composition of this embodiment has a polysiloxane skeleton. As methods for introducing the above-mentioned (v) polysiloxane compound during the synthesis of the (meth)acrylic resin, the following four methods can be mentioned. (1) A method of radical polymerization of a polysiloxane compound having a radically polymerizable group with the (meth)acrylic monomers described in the above (i) to (iv). Examples of the radically polymerizable group include (meth)acryloyl groups. Examples of commercially available polysiloxane compounds having a radically polymerizable group include Silaplane FM-0711, FM-0721, and FM-0725 manufactured by JNC Corporation, X-22-174BX, KF-2012, etc. manufactured by Shin-Etsu Silicone Co., Ltd. (2) A method of introducing a polysiloxane compound having a reactive functional group by reacting it with a reactive group previously introduced into a (meth)acrylic resin. Examples of the reactive functional group include a hydroxy group, an epoxy group, a carboxy group, an amino group, etc. Examples of commercially available polysiloxane compounds having a reactive functional group include Silaplane (trade name) series such as Silaplane FM-0421 and FM-4421 manufactured by JNC Corporation, resin-modified silicone oils such as X-22-173DX and X-22-170DX manufactured by Shin-Etsu Silicone Co., Ltd. (3) A method of introducing as a block copolymer by polymerizing the above-mentioned (meth)acrylic monomer using a polymer azo polymerization initiator having a polysiloxane skeleton. Examples of commercially available polymer azo polymerization initiators include, for example, VPS-1001N (trade name), a polymer azo polymerization initiator containing a polydimethylsiloxane unit, manufactured by Fujifilm Wako Pure Chemical Corporation. (4) A method of introducing as a block copolymer by using a polysiloxane compound having a mercapto group when polymerizing the above-mentioned (meth)acrylic monomer as a chain transfer agent. Examples of commercially available polysiloxane compounds having a mercapto group include, for example, X-22-167B manufactured by Shin-Etsu Silicone Co., Ltd. By using the above methods (1) to (4), a polysiloxane skeleton can be introduced into the central part, terminal, or side chain of the main skeleton of a (meth)acrylic resin.

[0029] As the above-mentioned (v) polysiloxane compound, it is preferable to use a polydimethylsiloxane compound from the viewpoint of more effectively imparting a smooth touch to the coating film.

[0030] In the (meth)acrylic resin, the number average molecular weight (Mn) of the structural unit having a polysiloxane skeleton is, for example, in the catalog value, preferably 500 or more, more preferably 700 or more, still more preferably 1000 or more, preferably 20000 or less, more preferably 15000 or less, and still more preferably 10000 or less. By setting the range of the number average molecular weight (Mn) to be equal to or higher than the above lower limit value, a smooth feeling can be imparted to the coating film. Also, by setting the range of the number average molecular weight (Mn) to be equal to or lower than the above upper limit value, it is considered that the polysiloxane compound is easily incorporated into the (meth)acrylic resin, and the generation of unreacted substances can be suppressed. By setting the number average molecular weight (Mn) to be equal to or lower than the above upper limit value, the compatibility between the polysiloxane compound and the (meth)acrylic resin is improved, and it is considered that the generation of a sticky feeling due to the polysiloxane compound existing as an unreacted substance can be suppressed.

[0031] The content of the structural unit having a polysiloxane skeleton in the (meth)acrylic resin in the present embodiment is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less with respect to 100% by mass of the total solid content of the coating composition. By setting the content of the structural unit having a polysiloxane skeleton in the (meth)acrylic resin within the above range, an amount of polysiloxane skeleton that can sufficiently impart a smooth feeling to the coating film can be introduced, and the touch feeling of the coating film can be made good.

[0032] The weight average molecular weight (Mw) of the (meth)acrylic resin is preferably 5000 to 50000, more preferably 7000 to 40000, still more preferably 10000 to 30000, and particularly preferably 15000 to 25000. By setting it to be equal to or higher than this lower limit value, the adhesion of the coating film to the substrate can be improved. Also, by setting it to be equal to or lower than this upper limit value, the generation of bubbles in the coating film and the like can be suppressed, and a good coating film can be obtained. (Meta) The weight average molecular weight (Mw) of the acrylic resin can be adjusted by conditions such as the polymerization reaction time, reaction temperature, and the amount of polymerization initiator used. The number average molecular weight Mn and the weight average molecular weight Mw can be measured in terms of standard polystyrene by gel permeation chromatography (GPC).

[0033] (Meta) The glass transition temperature (°C) of the acrylic resin is preferably 1 to 80°C, more preferably 1 to 75°C. By setting the above range, as described later, it becomes easier to adjust the glass transition temperature of the coating composition (excluding particles). Also, by setting the above range, the compatibility between the (meta)acrylic resin and the isocyanate curing agent, etc. becomes good, and the handleability during the synthesis of the coating composition can be improved. The glass transition temperature (°C) of the (meta)acrylic resin can be calculated and determined using the following Fox's equation based on the blending ratio of the monomers used. 1 / Tg = (W1 / Tg1) + (W2 / Tg2) + (W3 / Tg3) + ··· + (W n / Tg n ) [In the formula, Tg is the glass transition temperature (K) of the resin, W1, W2, W3 ··· W n is the mass fraction of each monomer, Tg1, Tg2, Tg3 ··· Tg n represents the glass transition temperature (K) of the homopolymer composed of the monomer corresponding to the mass fraction of each monomer.

[0034] In this specification, the glass transition temperature of the (meta)acrylic resin (not the glass transition temperature of the coating composition for measuring the glass transition temperature excluding particles from the coating composition described later, but the glass transition temperature of the (meta)acrylic resin alone) means the glass transition temperature obtained based on the above formula. For monomers with unknown glass transition temperatures, such as special monomers and polyfunctional monomers, the glass transition temperature is determined using only the monomers with known glass transition temperatures.

[0035] The content of the (meth)acrylic resin is preferably 1% by mass or more, preferably 2% by mass or more, and preferably 80% by mass or less, more preferably 75% by mass or less, based on 100% by mass of the total solid content of the coating composition. In particular, when the coating composition does not contain the polyol described below, the content of the (meth)acrylic resin is preferably 60% by mass or more and 80% by mass or less based on 100% by mass of the total solid content of the coating composition. This amount is appropriately determined from the handling properties, coating properties, etc. of the coating.

[0036] The production method of the (meth)acrylic resin is not particularly limited, and known methods can be appropriately applied. For example, it is preferably produced by a polymerization reaction, and more preferably produced by radical polymerization. Also, the polymerization may be any of known methods such as solution polymerization, suspension polymerization, and emulsion polymerization. Among these, solution polymerization is preferred from the viewpoint of precise control of polymerization, etc.

[0037] As the polymerization initiator for radical polymerization, known ones can be used. For example, azo-based initiators such as 1,1-azobis-1-cyclohexanecarbonitrile, azobisisobutyronitrile, 2,2-azobis(2-methylbutyronitrile), 2,2-azobis(2-methylpropionitrile), and 2,2-azobis(2,4-dimethylvaleronitrile); peroxide-based initiators such as benzoyl peroxide, t-butylperoxyoctanoate, diisobutyl peroxide, di(2-ethylhexyl) peroxypivalate, decanoyl peroxide, t-butylperoxy-2-ethylhexanoate, and t-butylperoxybenzoate; redox-based initiators such as hydrogen peroxide and iron(II) salt, persulfate and sodium bisulfite, etc., which are combinations of an oxidizing agent and a reducing agent. These can be used alone or in combination of two or more. The compounding amount of the polymerization initiator is not particularly limited, but when the total amount of the monomer mixture to be polymerized is 100 parts by mass, it is preferably 0.001 to 10 parts by mass.

[0038] In addition, during the polymerization reaction, known chain transfer agents, polymerization inhibitors, molecular weight regulators, etc. may be used as appropriate. Furthermore, the polymerization reaction may be carried out in one step or in two or more steps. The temperature of the polymerization reaction is not particularly limited, but it is adjusted as appropriate in consideration of the 10-hour half-life temperature of the polymerization initiator. Typically, it is in the range of 50°C to 200°C, preferably 80°C to 150°C.

[0039] (Polyol) The coating composition of this embodiment preferably contains a polyol, that is, a compound having two or more hydroxy groups in one molecule. The polyol can react with the polyisocyanate compound described later and can cure the coating film. The number of hydroxy groups that a polyol has in one molecule is usually 2 or more, preferably 2 to 6, more preferably 2 to 4. Since the above-mentioned (meth)acrylic resin contains a hydroxy group, it is generally classified as a polyol. However, the polyol in this embodiment excludes the above-mentioned (meth)acrylic resin.

[0040] The polyol preferably contains at least one polyol selected from the group consisting of polycaprolactone polyol, polycarbonate polyol, polyester polyol and polyether polyol. These chemical structures are moderately flexible and elastic. Therefore, the flexibility and elasticity of the coating film can be further enhanced, which is desirable in terms of absorbing external forces.

[0041] The polycaprolactone polyol can be used without particular limitation as long as it is a compound having a ring-opening structure of caprolactone and two or more hydroxy groups in one molecule. Specifically, polyols represented by any of the following general formulas (P-1) to (P-3) can be mentioned.

[0042]

Chemical formula

[0043] In general formula (P-1), R represents a divalent organic group. Examples of the divalent organic group include linear alkylene groups such as -CH2- and -C2H4-, branched alkylene groups such as -CH2-C(CH3)2-CH2-, and ether-containing groups such as -C2H4-O-C2H4-. Each X independently represents a linear or branched alkylene group. The number of carbon atoms in this alkylene group is preferably 3 to 7, more preferably 4 to 6. m and n each independently represent an integer of 1 or more. m and n are each preferably an integer of 2 to 20. Further, the sum of m and n is preferably 4 to 35.

[0044] In general formula (P-2), R represents a trivalent organic group. Examples of the trivalent organic group include a structure obtained by removing three hydrogen atoms from a linear or branched alkane. Each X independently represents a linear or branched alkylene group. The number of carbon atoms in this alkylene group is preferably 3 to 7, more preferably 4 to 6. l, m, and n each independently represent an integer of 1 or more. l, m, and n are each preferably an integer of 2 to 20. Further, the sum of l, m, and n is preferably 3 to 40.

[0045] In general formula (P-3), R represents a tetravalent organic group. Examples of the tetravalent organic group include a structure obtained by removing four hydrogen atoms from a linear or branched alkane. Each X independently represents a linear or branched alkylene group. The number of carbon atoms in this alkylene group is preferably 3 to 7, more preferably 4 to 6. k, l, m, and n each independently represent an integer of 1 or more. k, l, m, and n are each preferably an integer of 2 to 20. Further, the sum of k, l, m, and n is preferably 4 to 50.

[0046] As commercially available polycaprolactone polyols, for example, those with trade names such as the Placcel 200 series, Placcel 300 series, and Placcel 400 series manufactured by Daicel Corporation can be used.

[0047] Polycarbonate polyol can be used without particular limitation as long as it is a compound having a carbonate group represented by -O-(C=O)-O- and two or more hydroxy groups in one molecule. Polycarbonate polyol can be obtained by reacting one or more polyol raw materials (polyhydric alcohols) with a carbonic acid ester or phosgene. The polyol raw material is not particularly limited, and examples include aliphatic polyols, polyols having an alicyclic structure, and aromatic polyols. In the present embodiment, from the viewpoint of the flexibility of the coating film, an aliphatic polyol having no alicyclic structure is preferable. Examples of the carbonic acid ester include aliphatic carbonic acid esters such as dimethyl carbonate and diethyl carbonate, aromatic carbonic acid esters such as diphenyl carbonate, and cyclic carbonic acid esters such as ethylene carbonate. Among them, aliphatic carbonic acid esters are preferable, and dimethyl carbonate is particularly preferable, from the viewpoints of availability and ease of production. As commercially available polycarbonate polyols, for example, the Duranol (trade name) series manufactured by Asahi Kasei Corporation can be used. Among polycarbonate polyols, it is particularly preferable to contain polycarbonate diol. Thereby, a soft touch can be obtained when the coating film is touched with a finger. In addition, by lowering the Martens hardness of the coating film described later and increasing the flexibility and elasticity of the coating film, the generation of cracks during film formation can be suppressed.

[0048] Polyester polyol can be used without particular limitation as long as it is a compound having an ester group (-COO- or -OCO-) and two or more hydroxy groups in one molecule. The polyester polyol can be obtained by reacting one or more polyol raw materials (polyhydric alcohols) with an ester-forming compound such as a polycarboxylic acid or its ester, anhydride, halide, etc. The polyol raw material is not particularly limited, and examples thereof include the same polyol raw materials as those for the raw materials of the above polycarbonate polyol. There are also no particular restrictions on the ester-forming compounds such as polycarboxylic acids or their esters, anhydrides, halides, etc., and examples thereof include polyvalent carboxylic acids such as aliphatic dicarboxylic acid compounds, aromatic dicarboxylic acid compounds, alicyclic dicarboxylic acid compounds, tricarboxylic acid compounds, acid anhydrides of these polycarboxylic acids, halides, lower ester compounds, etc.

[0049] The polyether polyol can be used without particular limitation as long as it is a compound having an ether bond (-O-) and two or more hydroxy groups in one molecule. Specific compounds include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, random copolymers and block copolymers of ethylene oxide and propylene oxide, ethylene oxide and butylene oxide, etc.

[0050] In this embodiment, the polyol may be a compound corresponding to a plurality of polycaprolactone polyol, polycarbonate polyol, polyester polyol and polyether polyol. For example, the polyol may be a polyether polyester polyol having an ether bond and an ester bond.

[0051] The molecular weight of the polyol is preferably 300 to 3000, more preferably 500 to 2000, for example, in the catalog value. By setting the molecular weight to an appropriate value, the flexibility and elasticity of the coating film can be improved. The hydroxyl value of the polyol is preferably 50 to 300 mgKOH / g, more preferably 100 to 250 mgKOH / g. By adjusting the amount of hydroxyl groups to a suitable level, the crosslinked structure formed by the reaction with the polyisocyanate compound described below can be controlled, and it is expected that the flexibility, elasticity, etc. of the coating film will be further improved.

[0052] The content of polyol in the coating composition is usually 10 to 80% by mass, preferably 15 to 75% by mass, and more preferably 20 to 70% by mass, based on 100% by mass of the total solids content of the coating composition. The amount of polyol is usually 10 to 2500 parts by mass, preferably 20 to 2300 parts by mass, and more preferably 30 to 2200 parts by mass, based on 100 parts by mass of the (meth)acrylic resin. By using this range, it is possible to obtain sufficient performance derived from the polyol while also achieving a good balance with other components.

[0053] In this embodiment, the glass transition temperature (°C) of the coating composition for glass transition temperature measurement, from which the particles have been removed, is preferably −30°C or higher, more preferably −25°C or higher, and is also preferably 90°C or lower, more preferably 85°C or lower. By ensuring that the glass transition temperature is within the above range, it is possible to suppress the feeling of the coating film catching when touched with a finger (tight feeling) due to the coating film being too soft, and it is also possible to suppress the occurrence of cracks during film formation or in use due to the coating film being too hard. The coating composition for measuring glass transition temperatures obtained by excluding particles from the coating composition refers to a coating composition consisting of the materials constituting the coating composition other than the particles, i.e., the (meth)acrylic resin, the polyisocyanate compound, the polyol if a polyol is included, and the silicone additive if a silicone additive is included.

[0054] The glass transition temperature (°C) of the coating composition for glass transition temperature measurement, which is obtained by removing the particles from the coating composition, is determined by the following method. First, the above-mentioned paint composition for glass transition temperature measurement is applied to a polypropylene substrate by air spraying, and the coated substrate is heated at 80°C for 60 minutes. After heating, it is left standing for 4 weeks at 25°C and a relative humidity of 50% to obtain a coating film with a thickness of 50 μm. The coating film is peeled off from the substrate and cut into test pieces with a width of 5 mm and a length of 50 mm. Using the test pieces, the maximum value of the loss tangent tanδmax when measuring the dynamic viscoelasticity in the range of a frequency of 1.0 Hz and a temperature of -50 to 180°C under the conditions of 23°C and a relative humidity of 50% is defined as the glass transition temperature (°C).

[0055] (Polyisocyanate compound) The paint composition of this embodiment contains a polyisocyanate compound. The polyisocyanate compound can react with the hydroxy groups of the aforementioned (meth)acrylic resin to form a crosslinked structure. Also, when the paint composition contains the aforementioned polyol, it can react with the hydroxy groups of the polyol.

[0056] The polyisocyanate compound is preferably polyfunctional, that is, a compound having two or more isocyanate groups (including isocyanate groups protected by leaving groups) in one molecule. The number of functional groups of the polyisocyanate compound is more preferably 2 to 6 per molecule, and even more preferably 2 to 4 per molecule.

[0057] Examples of monofunctional isocyanate compounds include aliphatic isocyanates such as methyl isocyanate, butyl isocyanate, hexyl isocyanate, and octyl isocyanate, cycloaliphatic isocyanates such as cyclohexyl isocyanate and 4-methylcyclohexyl isocyanate, and aromatic isocyanates such as phenyl isocyanate, benzyl isocyanate, and naphthyl isocyanate.

[0058] Examples of the polyfunctional isocyanate compound include aliphatic diisocyanates such as lysine isocyanate, hexamethylene diisocyanate and trimethylhexane diisocyanate, cycloaliphatic 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 polyfunctional isocyanates having three or more functional groups such as lysine triisocyanate. Isocyanurate and biuret type adducts which are multimers of the isocyanate compound, and those obtained by adding the isocyanate compound to a polyhydric alcohol or a low molecular weight polyester resin can also be used as the polyisocyanate compound.

[0059] Note that as the polyisocyanate compound, biuret type, isocyanurate type, adduct type and the like are known. In the present embodiment, any of them can be used, but among them, it is preferable to use an isocyanurate type polyisocyanate compound, that is, a polyfunctional isocyanate having a cyclic skeleton of isocyanuric acid.

[0060] The polyisocyanate compound may be a so-called blocked isocyanate. In other words, part or all of the isocyanate groups of the polyisocyanate compound may be in the form of blocked isocyanate groups blocked by a protecting group. For example, the isocyanate group is blocked by an active hydrogen compound such as an alcohol type, a phenol type, a lactam type, an oxime type, and an active methylene type to form a blocked isocyanate group. In particular, when the coating composition of the present embodiment is a one-component system, a polyisocyanate compound having a blocked isocyanate group is preferable from the viewpoint of storage stability (stability over time).

[0061] As a commercially available product of the polyisocyanate compound, for example, the Duranate (trade name) series manufactured by Asahi Kasei Corporation can be used.

[0062] The content of the polyisocyanate compound in the coating composition is usually 10 to 80% by mass, preferably 15 to 75% by mass, based on 100% by mass of the total solid content of the coating composition. Further, the amount of the polyisocyanate compound is usually 10 to 1500 parts by mass, preferably 15 to 1400 parts by mass, based on 100 parts by mass of the (meth)acrylic resin. By setting the content of the polyisocyanate compound to be not less than the above lower limit value, the crosslinking between the (meth)acrylic resin and the polyisocyanate compound can be made dense, resulting in a strong coating film, and the solvent resistance and chemical resistance can be improved. Further, by setting the content of the polyisocyanate compound to be not more than the above upper limit value, it is possible to prevent unreacted isocyanate groups from reacting with moisture in the air after forming a coating film, which may prevent the formation of a suitable coating film.

[0063] From another aspect, it is preferable to set the molar ratio of the hydroxy group contained in the (meth)acrylic resin or polyol and the isocyanate group (including the blocked isocyanate group) contained in the polyisocyanate compound to an appropriate value. This molar ratio is also called the "equivalent ratio". Specifically, the molar ratio (NCO / OH) of the isocyanate group contained in the polyisocyanate compound to the hydroxy group contained in the (meth)acrylic resin or polyol is preferably 0.5 to 1.5, and more preferably 0.8 to 1.2. By setting the molar ratio within the above range, suitable coating film physical properties can be obtained.

[0064] The coating composition of this embodiment may be photosensitive or non-photosensitive, but is preferably non-photosensitive. More preferably, it is thermosetting. Since the coating composition is non-photosensitive, the weather resistance of the coating film is improved.

[0065] (Particles) The coating composition of this embodiment contains particles. The lower limit value of the average particle diameter of the particles is 1.0 μm or more, preferably 1.5 μm or more. By setting the average particle diameter of the particles to be not less than the above lower limit value, a part of the particles is likely to appear on the coating film surface, so it is considered that the contact area when a person's finger touches the coating film becomes small and a smooth touch can be obtained. In addition, the upper limit value of the average particle diameter of the particles is 100.0 μm or less, preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 15 μm or less. If the average particle diameter becomes too large, the unevenness on the coating film surface becomes large and the touch feeling becomes rough. Therefore, by setting the average particle diameter of the particles to be equal to or less than the above upper limit value, the touch feeling when touched by hand can be made smooth.

[0066] The average particle diameter of the particles in this embodiment is measured by the following Coulter counter method. The average particle diameter of the particles can be measured using a precision particle size distribution measuring device (for example, manufactured by Beckman Coulter, "Coulter Counter Multisizer 3") and its dedicated software. Put the electrolyte solution dedicated to the precision particle size distribution measuring device into the dedicated beaker of the precision particle size distribution measuring device and stir. Remove the dirt and bubbles in the aperture tube of the precision particle size distribution measuring device in advance. Add methanol and the measurement particles to another beaker, and disperse them using an ultrasonic cleaner to obtain a measurement sample. Drop the obtained measurement sample little by little into the dedicated beaker of the above-mentioned precision particle size distribution measuring device using a pipette. Adjust the measurement concentration to a concentration of about 10,000 counts per 10 seconds, and perform the measurement until the number of measured particles reaches 50,000. During the measurement, use an appropriate aperture diameter for measurement according to the volume average particle diameter of the particles to be measured. Analyze the obtained measurement data using the dedicated software attached to the device to calculate the volume average particle diameter.

[0067] The shape of the particles is not particularly limited, but considering the uniformity of the coating film, etc., it is preferably spherical.

[0068] The particles are preferably silica particles, acrylic particles, urethane particles, and crosslinked polyacrylic acid particles. Thereby, a smooth feeling when the coating film is touched with a finger can be imparted. In addition, it is preferable that the particles do not contain fluororesin particles. Although the detailed mechanism is unknown, thereby, the static friction coefficient (μS) when forming a coating film is reduced, and a smooth touch feeling can be more effectively imparted to the coating film. Only one type of particles may be used, or multiple types may be used in combination. The combined use of multiple types includes not only the combination of particles made of different materials, but also the combination of particles made of the same material but having different average particle diameters.

[0069] The content of particles in the coating composition (the total amount when including multiple types of particles) is usually 1 to 50% by mass, preferably 3 to 40% by mass, more preferably 5 to 40% by mass, still more preferably 8 to 40% by mass, and even more preferably 11 to 40% by mass with respect to 100% by mass of the total solid content of the coating composition. Also, the amount of particles is usually 5 to 2500 parts by mass, preferably 10 to 2200 parts by mass with respect to 100 parts by mass of the (meth)acrylic resin. By setting this numerical range, the particles can appropriately protrude on the coating film surface, a smooth touch can be imparted to the coating film, and the detachment of particles due to external force can be prevented.

[0070] (Other components) The coating composition of this embodiment may further contain other components as necessary. For example, it may contain a curing accelerator (such as a curing catalyst), an ultraviolet absorber, a light stabilizer, a dispersant, an antioxidant, etc.

[0071] (Solvent) The coating composition of this embodiment is typically used in a state where each component is dissolved or dispersed in a solvent. The solvent is an organic solvent in one aspect. Examples of the organic solvent include aromatic hydrocarbon solvents such as toluene and xylene, alcohol solvents such as methanol, ethanol, isopropyl alcohol, n-butanol, and isobutanol, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, and ester solvents such as ethyl acetate, propyl acetate, butyl acetate, and isobutyl acetate.

[0072] The amount of the solvent used is not particularly limited, but it can be used in an amount such that the concentration of the solid content (non-volatile component) is, for example, 5 to 90% by mass, preferably 10 to 85% by mass.

[0073] (Ratio of each component, etc.) By appropriately adjusting the quantitative ratio of each component, the coating composition of this embodiment can be expected to obtain a smooth touch when the coating film is touched with a finger. Particularly in this embodiment, it is important to adjust the molar ratio of the hydroxy group to the isocyanate group in the coating composition within the range of 0.5 to 1.5 in order to further improve the physical properties (such as flexibility) of the finally obtained coating film.

[0074] (Properties of the coating composition) Hereinafter, the properties of the coating composition of this embodiment will be described in detail.

[0075] In this embodiment, the upper limit value of the Martens hardness of the coating film is preferably 200 N / mm 2 or less, more preferably 170 N / mm 2 or less, and even more preferably 140 N / mm 2 or less. The lower limit value of the Martens hardness of the coating film is 1 N / mm 2 or more. When the Martens hardness is below the above upper limit value, that is, when the coating film is not too hard, it is possible to suppress cracks from occurring in the coating film during film formation or in practical use when the film thickness is thick. When the Martens hardness is above the above lower limit value, that is, when the coating film is not too soft, the feeling of stickiness when the coating film is touched with a finger can be suppressed, and a smooth touch can be imparted.

[0076] The Martens hardness in this embodiment is measured after forming the coating film. The coating film is formed by coating the coating composition on an acrylonitrile / butadiene / styrene copolymer synthetic resin substrate with an air spray, heating the coated substrate at 80 °C for 60 minutes, and after heating, allowing it to stand at 25 °C and a relative humidity of 50% for 4 weeks to obtain a coating film with a film thickness of 20 μm. The Martens hardness of the coating film obtained as described above is measured by pressing a Vickers indenter with a load of 4 mN into the coating film for 20 seconds using a microhardness tester at 23°C and a relative humidity of 50%. The Martens hardness is calculated using the following formula, where Fmax is the maximum test force and Hmax is the indentation depth at Fmax. Martens hardness (N / mm 2 )=Fmax / (26.43×(Hmax) 2 )

[0077] In this embodiment, the upper limit of the static friction coefficient (μS) of the coating film is set to a value when the Martens hardness is 30 N / mm 2 In the case of the above, the static friction coefficient (μS) of the coating film is preferably 1.4 or less, and more preferably 1.2 or less. 2 If it is greater than this, it is preferably 1.0 or less, and more preferably 0.8 or less. The static friction coefficient of a coating film is considered to represent the feeling of slipperiness when the coating film is touched with a finger and begins to move. By having the static friction coefficient be equal to or less than the above upper limit, a preferable tactile feel can be obtained with less tightness when the coating film is touched with a finger.

[0078] In this embodiment, the upper limit of the average dynamic friction coefficient (μK) of the coating film is set to a value when the Martens hardness is 30 N / mm 2 In the case where the Martens hardness is 30 N / mm or less, the upper limit of the average dynamic friction coefficient (μK) of the coating film is preferably 0.4 or less, and more preferably 0.35 or less. 2 If it is greater than this, it is preferably 0.4 or less, more preferably 0.3 or less, and even more preferably 0.25 or less. The average dynamic friction coefficient of a coating film is considered to represent the feeling of a finger touching the coating film and starting to move it while moving it back and forth across the coating film. When the average dynamic friction coefficient of the coating film is equal to or less than the above upper limit, a smooth feel can be obtained when a finger touches the coating film and starts to move.

[0079] In this embodiment, when the static friction coefficient of the coating film is μS and the average dynamic friction coefficient is μK, the upper limit of the sum of μS and μK is set to 30 N / mm 2 In the case where the Martens hardness is 30 N / mm or less, the sum of μS and μK is preferably 1.8 or less, and more preferably 1.5 or less. 2 If it is greater than this, it is preferably 1.4 or less, more preferably 1.2 or less, and even more preferably 1.0 or less. The sum of μS and μK is a useful index for comprehensively evaluating the good tactile feel when the coating film is first touched with a finger, without any stiffness, and the smooth tactile feel while moving the finger over the coating film after starting to move it. When the sum of μS and μK is equal to or less than the upper limit, the coating film has a smooth feel with less tightness, which is a feeling that combines the feeling of slipping when touching it with a finger and the feeling of sliding your finger over it.

[0080] The static friction coefficient and the average dynamic friction coefficient are measured by the following method. The same coating film as used for measuring the Martens hardness was used for the measurement. Under conditions of 23°C and a relative humidity of 50%, the coating film was attached to a static and dynamic friction coefficient measuring instrument (TL201Tt, manufactured by Trinity Lab Co., Ltd.), and the tactile contactor (a contactor with a hardness equivalent to that of a fingertip) attached to the measuring instrument was placed on a surface of 1.5 cm2 in contact with the coating film. 2 The tactile contactor is brought into contact with the coating under the above conditions, and moved 30 mm at a speed of 30 mm / s while applying a load of 10 g, to measure the static friction coefficient (μS) and average kinetic friction coefficient (μK). The maximum value of the friction coefficient measured in the range of 0 mm or more and less than 10 mm of movement of the tactile contactor is the static friction coefficient (μS), and the average value of the measured values of the friction coefficient measured in the range of 10 mm or more and 25 mm of movement of the tactile contactor is the average kinetic friction coefficient (μK).

[0081] In this embodiment, the arithmetic mean roughness (Ra) of the coating film is preferably 0.1 μm or more, more preferably 0.3 μm or more. Also, the arithmetic mean roughness (Ra) of the coating film is preferably 10.0 μm or less, more preferably 5.0 μm or less, and even more preferably 3.0 μm or less. By being equal to or greater than the above lower limit value, a part of the particles appears on the surface of the coating film, so that when touched by a finger, the contact area becomes small and a smooth touch can be obtained. Also, by being equal to or less than the above upper limit value, the rough touch when touching the coating film with a finger can be suppressed. The arithmetic mean roughness (Ra) is measured using the same coating film as the coating film used for the measurement of the Martens hardness described above, by a method conforming to JIS B0633:2001, using a surface roughness measuring instrument, using a stylus with a radius of 2 μm, and measuring under the conditions of a moving speed of 0.5 mm / s, 23 °C, and a relative humidity of 50%.

[0082] In this embodiment, the 85° gloss value of the coating film is preferably 3 or more, more preferably 5 or more. Also, the 85° gloss value of the coating film is preferably 90 or less, more preferably 80 or less. When the uneven shape of the coating film surface becomes large, the 85° gloss value becomes low. On the other hand, when the coating film surface becomes flat, the 85° gloss value becomes high. By making the 85° gloss value equal to or greater than the above lower limit value, the coating film surface becomes flat, and it is possible to suppress an increase in the contact area of the finger and the appearance of a hard feeling. By making the 85° gloss value equal to or less than the above upper limit value, it is possible to prevent the uneven shape from becoming large and resulting in a rough touch. The 85° gloss value is measured by a method conforming to JIS Z8741:1997 under the conditions of 23 °C and a relative humidity of 50%, using the same coating film as the coating film used for the measurement of the Martens hardness described above.

[0083] As described above, the embodiments of the present invention have been described, but these are examples of the present invention, and various configurations other than the above can be adopted. Also, the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. within the range that can achieve the object of the present invention are included in the present invention. Examples of reference embodiments are appended below. [1] A (meth)acrylic resin having a hydroxy group, a polyisocyanate compound, and particles having an average particle diameter of 1.0 μm or more and 100.0 μm or less, wherein the (meth)acrylic resin has a polysiloxane skeleton, a coating composition. [2] The coating composition according to [1], wherein the martens hardness measured under the following [Martens hardness measurement conditions] of the coating film formed under the conditions described in the following [Coating film formation conditions] is 1 N / mm 2 or more and 200 N / mm 2 or less, a coating composition. [Coating film formation conditions] The coating composition is applied onto an acrylonitrile / butadiene / styrene copolymer synthetic resin substrate by air spraying, and the coated substrate is heated at 80 °C for 60 minutes. After heating, the substrate is allowed to stand for 4 weeks under the conditions of 25 °C and a relative humidity of 50% to obtain a coating film with a film thickness of 20 μm. [Martens hardness measurement conditions] Using the coating film formed under the [Coating film formation conditions], under the conditions of 23 °C and a relative humidity of 50%, using a microhardness tester, a Vickers indenter with a load of 4 mN is applied to the coating film and pushed in for 20 seconds to measure the martens hardness. The martens hardness is calculated by the following formula when the maximum test force is Fmax and the indentation depth by Fmax is Hmax. Martens hardness (N / mm 2 ) = Fmax / (26.43 × (Hmax) 2 ) [3] The coating composition according to [2], wherein when the static friction coefficient measured under the conditions described in the following [Friction coefficient measurement conditions] of the coating film formed under the conditions described in the [Coating film formation conditions] is μS and the average kinetic friction coefficient is μK, when the martens hardness is 30 N / mm 2 or less, the value of μS + μK is 1.8 or less, and when the martens hardness is greater than 30 N / mm 2 or more, the value of μS + μK is 1.4 or less, a coating composition. [Friction coefficient measurement conditions] Using the coating film formed under the [Coating film formation conditions], under the conditions of 23 °C and a relative humidity of 50%, the coating film is mounted on a static and kinetic friction coefficient measuring machine (manufactured by Trinity Lab Co., Ltd., TL201Tt), and a tactile contact element attached to the measuring machine is used with a contact area of 1.5 cm 2 Under the conditions described above, the tactile contactor is brought into contact with the coating film, and while applying a load of 10 g, the tactile contactor is moved 30 mm at a speed of 30 mm / s to measure the coefficient of static friction (μS) and the average coefficient of kinetic friction (μK). The maximum value of the coefficient of friction measured in the range where the moving distance of the tactile contactor is 0 mm or more and less than 10 mm is defined as the coefficient of static friction (μS), and the average value of the measured values of the coefficient of friction measured in the range where the moving distance of the tactile contactor is 10 mm or more and 25 mm or less is defined as the average coefficient of kinetic friction (μK). [4] [1]~[3] Any one of the coating compositions according to item The coating composition, wherein the glass transition temperature (°C) of the coating composition for glass transition temperature measurement obtained by removing the particles from the coating composition is -30°C or more and 90°C or less, as measured under the conditions described in the following [Glass transition temperature measurement conditions]. [Glass transition temperature measurement conditions] The coating composition for glass transition temperature measurement is applied to a polypropylene substrate by air spraying, the coated substrate is heated at 80°C for 60 minutes, and after heating, it is allowed to stand at 25°C and a relative humidity of 50% for 4 weeks to obtain a coating film with a thickness of 50 μm. The coating film is peeled off from the substrate, cut into pieces with a width of 5 mm and a length of 50 mm to obtain test pieces. Using the test pieces, the maximum value of the loss tangent tanδmax when measuring the dynamic viscoelasticity at a frequency of 1.0 Hz and in the temperature range of -50 to 180°C under the conditions of 23°C and a relative humidity of 50% is defined as the glass transition temperature (°C). [5] [1]~[4] Any one of the coating compositions according to item The coating composition, wherein the arithmetic mean roughness (Ra) measured by the following [Arithmetic mean roughness measurement method] of the coating film formed under the conditions described in the following [Coating film formation conditions] is 0.1 μm or more and 10.0 μm or less. [Coating film formation conditions] The coating composition is applied to an acrylonitrile / butadiene / styrene copolymer synthetic resin substrate by air spraying, the coated substrate is heated at 80°C for 60 minutes, and after heating, it is allowed to stand at 25°C and a relative humidity of 50% for 4 weeks to obtain a coating film with a thickness of 20 μm. [Arithmetic mean roughness measurement method] Using the coating film formed under the above [Coating film formation conditions], in accordance with the method conforming to JIS B0633:2001, using a surface roughness measuring instrument, a stylus with a radius of 2 μm is used, and the arithmetic mean roughness (Ra) is measured under the conditions of a moving speed of 0.5 mm / s, 23°C, and a relative humidity of 50%. [6] [1]~[5] Any one of the coating compositions according to item A coating composition in which the 85° gloss value measured by the method conforming to JIS Z8741:1997 under the conditions of 23°C and 50% relative humidity of the coating film formed under the conditions described in [Coating Film Formation Conditions] below is 3 or more and 90 or less. [Coating Film Formation Conditions] The coating composition is applied onto an acrylonitrile / butadiene / styrene copolymer synthetic resin substrate by air spraying, the coated substrate is heated at 80°C for 60 minutes, and after heating, it is allowed to stand for 4 weeks under the conditions of 25°C and 50% relative humidity to obtain a coating film with a film thickness of 20 μm. [7] A coating composition according to any one of [1] to [6], wherein the content of the (meth)acrylic resin is 1% by mass or more and 80% by mass or less based on 100% by mass of the total solid content of the coating composition. [8] A coating composition according to any one of [1] to [7], wherein the content of the structural unit having a polysiloxane skeleton is 0.1% by mass or more and 20% by mass or less based on 100% by mass of the total solid content of the coating composition. [9] A coating composition according to any one of [1] to [8], further comprising a polyol.

[10] A coating composition according to [9], wherein the polyol contains a carbonate diol.

[11] A coating composition according to any one of [1] to

[10] , wherein the particles are composed of one or more selected from silica particles, acrylic particles, urethane particles, and crosslinked polyacrylic acid particles.

[12] A coating composition according to any one of [1] to

[11] , wherein the number average molecular weight (Mn) of the structural unit having a polysiloxane skeleton in the (meth)acrylic resin is 500 or more and 20,000 or less.

Example

[0084] Embodiments of the present invention will be described in detail based on examples and comparative examples. It should be noted that the present invention is not limited to the examples.

[0085] <Synthesis Example 1> 80 parts by mass of methyl isobutyl ketone was charged into a flask equipped with a stirrer, a thermometer, a condenser and a nitrogen gas inlet tube, and the temperature was raised to 115°C. Separately, a mixed solution (monomer solution) containing 36 parts by weight of methyl methacrylate (MMA), 18 parts by weight of butyl acrylate (BA), 10 parts by weight of 2-hydroxyethyl methacrylate (HEMA), 30 parts by weight of polycaprolactone-modified hydroxyethyl acrylate (Daicel Corporation, PLACCEL FA5), 1 part by weight of methacrylic acid (MAA), 5 parts by weight of one-terminal methacrylate-modified polydimethylsiloxane (JNC Corporation, Silaplane FM-0721), 10 parts by weight of methyl isobutyl ketone, and 2 parts by weight of 1,1'-azobis-cyclohexane-1-carbonitrile (Fujifilm Wako Pure Chemical Industries, Ltd., V-40) was prepared. This monomer solution was added dropwise to the flask over 2 hours, maintained at 115 ° C., and reacted for 3 hours with stirring. Heating was stopped and the mixture was cooled to room temperature to obtain a resin solution (solids content: 50% by weight) containing a (meth)acrylic resin. The resulting (meth)acrylic resin had a number average molecular weight (Mn) of 5,800 and a weight average molecular weight (Mw) of 20,000.

[0086] The hydroxyl value, weight average molecular weight (Mw) of the (meth)acrylic resin obtained in Synthesis Example 1 and the glass transition temperature (°C) calculated from the blending ratio of the monomers used based on the Fox equation described above were as shown in Table 1 below.

[0087] <Synthesis Examples 2 to 6> Monomers were prepared according to the compounding ratios (values are parts by mass) shown in Table 1 below, and resin solutions (solid content: 50% by mass) containing various (meth)acrylic resins were obtained in the same manner as in Synthesis Example 1. The hydroxyl value, weight average molecular weight (Mw), and glass transition temperature (calculated value) of each resin were as shown in Table 1 below.

[0088] In Table 1, Plaxel FA5, Silaplane FM-0711, Silaplane FM-0721, and Silaplane FM-0725 are the following monomers. For the other monomers, commercially available products were used as appropriate. Placcel FA5: Manufactured by Daicel Corporation, polycaprolactone-modified hydroxyethyl acrylate (caprolactone 5 mol adduct, molecular weight 689, hydroxyl value 74 - 84 mgKOH / g) Silaplane FM-0711: Manufactured by JNC Corporation, monomethyl methacrylate-modified polydimethylsiloxane (number average molecular weight (Mn): 1000) Silaplane FM-0721: Manufactured by JNC Corporation, monomethyl methacrylate-modified polydimethylsiloxane (number average molecular weight (Mn): 5000) Silaplane FM-0725: Manufactured by JNC Corporation, monomethyl methacrylate-modified polydimethylsiloxane (number average molecular weight (Mn): 10000)

[0089] Here, the hydroxyl value, number average molecular weight (Mn), weight average molecular weight (Mw), and glass transition temperature of each obtained (meth)acrylic resin were determined by the following methods.

[0090] <Hydroxyl value> Measured and calculated according to the method specified in "7.1 Neutralization titration method" of JIS K 0070 "Test methods for acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponifiable matter of chemical products". Note that when calculating the hydroxyl value, the value of the acid value is also required. The value of the acid value was also measured and calculated according to the method specified in "3.1 Neutralization titration method" of the same JIS standard.

[0091] <Number average molecular weight, weight average molecular weight> Measured and calculated by gel permeation chromatography (GPC). The equipment, conditions, etc. used are as follows. Equipment used: HLC8220GPC (manufactured by Tosoh Corporation) Columns used: TSKgel SuperHZM-M, TSKgel GMHXL-H, TSKgel G2500HXL, TSKgel G5000HXL (manufactured by Tosoh Corporation) Column temperature: 40 °C Standard substances: TSKgel standard polystyrenes A1000, A2500, A5000, F1, F2, F4, F10 (manufactured by Tosoh Corporation) Detector: RI (differential refractive index) detector Eluent: Tetrahydrofuran Flow rate: 1 ml / min

[0092] <Glass transition temperature of (meth)acrylic resin> The glass transition temperature of the (meth)acrylic resin was calculated based on the following Fox's equation according to the blending ratio of the monomers used. 1 / Tg = (W1 / Tg1) + (W2 / Tg2) + (W3 / Tg3) + ··· + (W n / Tg n ) [In the formula, Tg is the glass transition temperature (K) of the (meth)acrylic resin to be determined, W1, W2, W3 ··· W n are the mass fractions of each monomer, and Tg1, Tg2, Tg3 ··· Tg n represent the glass transition temperatures (K) of the homopolymers composed of the monomers corresponding to the mass fractions of each monomer.] Note that for Cyralplane FM-0711, Cyralplane FM-0721, and Cyralplane FM-0725 described in Table 1, since the glass transition temperature is unknown, they were not considered, and the glass transition temperature was determined using only the monomers for which the glass transition temperature was known.

[0093]

Table 1

[0094] <Examples 1 to 17, Comparative Examples 1 to 15> The obtained Synthesis Examples 1 to 6 and other materials (polyol, polyisocyanate compound, silicone additive, particles) shown in Tables 2 to 4 were mixed in the amounts (unit: parts by mass) shown in each table. Then, the solid content concentration was adjusted with butyl acetate to prepare a paint composition with a solid content of 30% by mass. In each table, the amount of the (meth)acrylic resin represents the amount of the resin (solid content) contained in the resin solution, rather than the amount as the resin solution (solid content: 50% by mass). Also, in each table, the amount of materials other than the (meth)acrylic resin (polyol, polyisocyanate compound, silicone additive, particles) also represents the amount of the solid content in each material.

[0095] Among the compounds in each table, the information about those other than the (meth)acrylic resin is as follows.

[0096] (Polyol) Polycaprolactone diol: manufactured by Daicel Corporation, Placcel 208 (molecular weight 830, hydroxyl value 130 - 140 mgKOH / g) Polycaprolactone triol: manufactured by Daicel Corporation, Placcel 308 (molecular weight 850, hydroxyl value 190 - 200 mgKOH / g) Polycaprolactone tetraol: manufactured by Daicel Corporation, Placcel 410D (molecular weight 1000, hydroxyl value 216 - 232 mgKOH / g) Carbonate diol: manufactured by Asahi Kasei Corporation, Duranol T5652 (molecular weight 2000, hydroxyl value 51 - 61 mgKOH / g)

[0097] (Hardener: Polyisocyanate compound) Duranate TPA - 100: manufactured by Asahi Kasei Corporation, isocyanurate type of hexamethylene diisocyanate (isocyanate group content 23% by mass, solid content 100% by mass)

[0098] (Silicone additive) BYK - 370: manufactured by BYK - Chemie Japan Co., Ltd., hydroxyl group - containing polyether - modified polydimethylsiloxane solution (solid content 20% by mass)

[0099] (Particles) MEK - ST - 40: manufactured by Nissan Chemical Industries, Ltd., methyl ethyl ketone dispersion solution of nanosilica particles (silica particles 40% by mass), average particle diameter: 12 nm Nip Seal E-1011: Manufactured by Tosoh Silica Corporation, silica particles, average particle size: 1.5 μm Silicia 435: Manufactured by Fuji Silicia Chemical Ltd., silica particles, average particle size: 2.5 μm Art Pearl GR-800: Manufactured by Negami Kogyo Co., Ltd., acrylic particles, average particle size: 6 μm Art Pearl GR-400: Manufactured by Negami Kogyo Co., Ltd., acrylic particles, average particle size: 15 μm Art Pearl GR-200: Manufactured by Negami Kogyo Co., Ltd., acrylic particles, average particle size: 32 μm Art Pearl JB-800T: Manufactured by Negami Kogyo Co., Ltd., urethane particles, average particle size: 6 μm Art Pearl C-400: Manufactured by Negami Kogyo Co., Ltd., urethane particles, average particle size: 15 μm Art Pearl C-100: Manufactured by Negami Kogyo Co., Ltd., urethane particles, average particle size: 50 μm Tech Polymer ACP-8C: Manufactured by Sekisui Chemical Co., Ltd., crosslinked polyacrylic acid particles, average particle size: 8 μm Tech Polymer ARX-30: Manufactured by Sekisui Chemical Co., Ltd., crosslinked polyacrylic acid particles, average particle size: 30 μm

[0100] <Average particle size (measured by Coulter counter method)> Regarding the average particle size of the particles, the following measurements were made using the following apparatus, conditions, etc. (Apparatus, conditions, etc. used for average particle size measurement) · Measuring apparatus: Precision particle size distribution measuring apparatus (manufactured by Beckman Coulter, "Coulter Counter Multisizer 3") · Dedicated software attached to the apparatus: Manufactured by Beckman Coulter, "Beckman Coulter Multisizer 3 Version3.51" · Electrolytic aqueous solution: Manufactured by Beckman Coulter, "ISOTON II" · Aperture diameter: Depending on the average particle size of the particles to be measured, the following two types were used appropriately. (When the average particle size is 1.5 μm or 2.5 μm) 20 μm (When the average particle diameters are 6.0 μm, 8.0 μm, 15 μm, 30 μm, 32 μm, and 50 μm) 100 μm (Average particle diameter measurement method) 1. Approximately 200 mL of the above electrolytic aqueous solution was placed in a 250 mL round-bottom glass beaker dedicated to the above precision particle size distribution measuring device, set on the sample stand, and stirred with a stirrer rod. Then, the dirt and bubbles in the aperture tube were removed in advance by the "flush of the aperture tube" function of the dedicated software attached to the device. 2. 19 g of methanol and 1 g of the measurement particles were added to a 50 mL beaker, and dispersed at 28 kHz for 2 minutes using an ultrasonic cleaner (manufactured by AS ONE Corporation, VS-100III) to obtain a measurement sample. 3. Using a pipette, the measurement sample adjusted in 2. was gradually dropped into the round-bottom beaker in 1., and the measurement concentration was adjusted to a concentration at which about 10,000 counts were made per 10 seconds. Then, the measurement was carried out until the number of measured particles reached 50,000. The measurement concentration was appropriately adjusted according to the volume average particle diameter of the particles to be measured. For example, it was about 1% when the volume average particle diameter was 1.5 μm and about 4% when the volume average particle diameter was 8.0 μm. Also, according to the volume average particle diameter of the particles, the measurement was carried out using the above aperture diameter. 4. The measurement data obtained in 3. was analyzed using the dedicated software attached to the device to calculate the volume average particle diameter (the volume average particle diameter can be calculated by taking the average value in the particle diameter distribution based on the volume of the measured particle diameters).

[0101] <Average particle diameter (measurement by transmission electron microscope)> Regarding the average particle diameter of MEK-ST-40, since the particles were fine and below the measurement lower limit of the method described in the above <Average particle diameter (measurement by Coulter counter method)>, the measurement was carried out by the following method. First, the particles were diluted with methanol to a concentration of 0.1% by mass, and the sample was dispersed for 1 minute using an ultrasonic disperser to obtain a dispersion. The resulting dispersion was dropped onto the sample stage of the microscope used for measurement, and the methanol was dried at room temperature and atmospheric pressure. After drying, the particles were sputtered to coat the particle surfaces with approximately 10 nm of gold, and this was used as the sample for observation. The obtained sample was observed and images were taken using a transmission electron microscope at an accelerating voltage of 200 kV and an appropriate measurement magnification. From the images taken, the circle-equivalent diameters of 500 particles judged to be primary particles (non-aggregated particles) were measured, and the average value was taken as the number-average particle diameter.

[0102] <Preparation of coating film for evaluation> Using each of the coating compositions prepared in the Examples and Comparative Examples, evaluation coating films were formed as follows. First, each coating composition was applied by air spray to an ABS (acrylonitrile, butadiene, styrene copolymer synthetic resin) substrate (manufactured by TP Giken Co., Ltd., JIS K6873 compliant product), and then the coated substrate was heated for 60 minutes in a safe-type oven set at 80°C. After heating, the substrate was left to stand for 4 weeks in an atmosphere of 25°C and 50% relative humidity, yielding a substrate with an evaluation coating film with a thickness of 20 μm. The evaluation coating film thus obtained was used to perform the following various physical property tests (except for the <Glass transition temperature of the coating composition for glass transition temperature measurement obtained by removing particles from the coating composition> described below). The results of the various physical property tests are shown in Tables 2 to 4 below.

[0103] <Martens hardness> The Martens hardness of the evaluation coating (with substrate) obtained in <Preparation of Evaluation Coating> was measured using the following method in an atmosphere of 23°C and 50% relative humidity. Specifically, using a microhardness testing device (Fisher Instruments, Fischerscope HM2000, ISO 14577 compliant), a Vickers indenter (square pyramidal diamond indenter) with a load of 4 mN was pressed into the evaluation coating (with substrate) for 20 seconds. Note that care was taken to ensure that the indenter penetration depth was less than 20 μm (so that the indenter did not reach the substrate). The Martens hardness was calculated using the following formula. Martens hardness (N / mm 2 ) = Fmax / (26.43 × (Hmax) 2 ) Fmax: Maximum test force Hmax: Penetration depth at Fmax

[0104] <Coefficient of friction> Using the evaluation coating film (with substrate) obtained in <Preparation of Evaluation Coating Film>, the static coefficient of friction (μS) and the average dynamic coefficient of friction (μK) were measured. Specifically, in an atmosphere of 23°C and 50% relative humidity, the evaluation coating film (with substrate) was set on a static and dynamic friction measuring machine (manufactured by Trinity Lab Co., Ltd., TL201Tt), and a tactile contactor (a contactor having a hardness equivalent to that of a fingertip: contact area 1.5 cm 2 ) attached to the measuring instrument was brought into contact with the evaluation coating film, and while applying a load of 10 g, the contactor was moved 30 mm at a speed of 30 mm / s to measure the static coefficient of friction (μS) and the average dynamic coefficient of friction (μK). Note that the maximum value measured in the range where the moving distance of the tactile contactor is less than 0 to 10 mm was taken as the static coefficient of friction (μS) (the largest resistance observed immediately after the start of sliding), and the average value of the measured values in the range where the moving distance of the tactile contactor is 10 to 25 mm was calculated as the average dynamic coefficient of friction (μK) (the resistance in the stable region after the start of sliding). From the obtained values of the static coefficient of friction (μS) and the average dynamic coefficient of friction (μK), the sum of the static coefficient of friction and the average dynamic coefficient of friction (μS + μK) was calculated.

[0105] <Arithmetic mean roughness (Ra)> Using the evaluation coating film (with substrate) obtained in <Preparation of Evaluation Coating Film>, in accordance with the method conforming to JIS B0633:2001 (Geometrical Product Specifications (GPS) - Surface texture: Profile method - Methods and procedures for the evaluation of surface texture), in an atmosphere of 23°C and 50% relative humidity, the arithmetic mean roughness (Ra) was measured using a surface roughness measuring machine (manufactured by Kosaka Laboratory Ltd., SE300). Note that a stylus with a tip radius of 2 μm was used, and the measurement was carried out at a moving speed of 0.5 mm / s.

[0106] <Gloss value at 85°> Using the evaluation coating film (with substrate) obtained in <Preparation of Coating Film for Evaluation>, the gloss value at 85° was measured using a gloss meter (micro-gloss, manufactured by BYK Gardner) in accordance with the method specified in JIS Z8741:1997 under an atmosphere of 23°C and 50% relative humidity.

[0107] <Glass transition temperature of the coating composition for measuring glass transition temperature excluding particles from the coating composition> Among the various coating compositions described in Tables 2 to 4 shown below, the constituent materials excluding particles, that is, the (meth)acrylic resins, polyols, polyisocyanate compounds, and silicone additives obtained in Synthesis Examples 1 to 6 were used to prepare a coating composition for measuring glass transition temperature in the same manner as the methods described in <Examples 1 to 17, Comparative Examples 1 to 15>. Using the obtained coating composition for measuring glass transition temperature, a coating film for measuring glass transition temperature was formed as follows: First, each coating composition for measuring glass transition temperature was spray-coated onto a polypropylene substrate (manufactured by TP Giken Co., Ltd., compliant with JIS K6921) using an air spray, and then the coated substrate was heated in a cabinet oven set at 80°C for 60 minutes. After heating, the substrate was allowed to stand for 4 weeks under an atmosphere of 25°C and 50% relative humidity to obtain a substrate provided with a coating film having a film thickness of 50 μm. The coating film was peeled off from the substrate and further cut into strips having a width of 5 mm and a length of 50 mm, which were used as test pieces for measurement. Using these test pieces, dynamic viscoelasticity measurement was performed under the following conditions in an atmosphere of 23°C and 50% relative humidity. The maximum value of the loss tangent tanδmax obtained from this measurement was taken as the glass transition temperature (°C) of the coating composition for measuring glass transition temperature excluding particles from the coating composition. The results are shown in Tables 2 to 4 shown below. Apparatus: Dynamic viscoelasticity measurement apparatus RSA3 (manufactured by TA Instruments) Measurement mode: Non-resonant forced vibration method Temperature increase rate: 5.0°C / min Measurement interval: 12 / min Frequency: 1.0 Hz Temperature range: -50 to 180 °C

[0108] <Touch evaluation> Using the evaluation coating film (with substrate) obtained in <Preparation of evaluation coating film>, 20 monitors (10 adult males and 10 adult females) touched the coating film with their fingers in an atmosphere of 23 °C and 50% relative humidity, scored based on the following evaluation criteria (relative evaluation), and the average value was taken as the evaluation score. The results are shown in Tables 2 to 4 below. (Evaluation criteria) [Hardness of coating film] 1: Feels hard. 2: Somewhat hard to feel. 3: Neither can be said. 4: Somewhat soft to feel. 5: Feels soft. [Sticky feeling] 1: Has a sticky feeling. 2: Somewhat sticky feeling. 3: Neither can be said. 4: Somewhat no sticky feeling. 5: No sticky feeling. [Smooth touch] 1: Not smooth. 2: Somewhat not smooth. 3: Neither can be said. 4: Somewhat smooth. 5: Smooth. [Touch feeling] 1: Bad touch feeling. 2: Somewhat bad touch feeling. 3: Neither can be said. 4: Somewhat good touch feeling. 5: Good touch feeling.

[0109] <Coating film appearance evaluation (slimy feeling)> Using the evaluation coating film (with substrate) obtained in <Preparation of Coating Film for Evaluation>, 20 monitors (10 adult males and 10 adult females) evaluated the appearance of the coating film visually and by touch in an atmosphere of 23°C and 50% relative humidity, and evaluated it based on the following evaluation criteria. The results are shown in Tables 2 to 4 below. (Evaluation Criteria) 〇: There is no sticky feeling on the appearance of the coating film. ×: There is a sticky feeling on the appearance of the coating film.

[0110]

Table 2

[0111] Considerations on Examples 1 to 6 and Comparative Examples 1 to 5 In Table 2, the coating compositions containing a (meth)acrylic resin having a polysiloxane skeleton and particles with an average particle diameter of 1.0 μm or more and 100.0 μm or less had good μS + μK values, and a smooth touch was obtained when touching the coating film (Examples 1 to 6). Also, it was found that the smaller the average particle diameter of the particles, the smoother the touch when touching the coating film, and the better the touch feeling (Examples 1, 2, 5, and 6). On the other hand, the coating compositions not containing a (meth)acrylic resin having a polysiloxane skeleton did not have good μS + μK values, and the smooth touch was inferior to that of Examples 1 to 6 (Comparative Examples 1, 2, 5). Among them, in Comparative Example 2, a sticky feeling occurred and a suitable coating film could not be obtained (Note that Example 1 and Comparative Example 2 have the same content of the structural unit having a polysiloxane skeleton contained in the coating composition). Also, in the coating compositions not containing particles or having an average particle diameter of less than 1.0 μm for the particles, the μS + μK values were not good, and the smooth touch was inferior to that of Examples 1 to 6 (Comparative Examples 3, 4).

[0112]

Table 3

[0113] Considerations on Examples 7 to 14 and Comparative Examples 6 to 10 In Table 3, the coating composition containing a (meth)acrylic resin having a polysiloxane skeleton and particles with an average particle diameter of 1.0 μm or more and 100.0 μm or less had a good value of μS + μK, and a smooth touch was obtained when touching the coating film (Examples 7 to 14). On the other hand, the coating composition not containing a (meth)acrylic resin having a polysiloxane skeleton did not have a good value of μS + μK, and the smooth touch was inferior to that of Examples 7 to 14 (Comparative Examples 6, 7, and 10). Among them, in Comparative Example 7, stickiness occurred and a suitable coating film could not be obtained (note that in Comparative Example 7 and Example 7, the content of the structural unit having a polysiloxane skeleton contained in the coating composition is the same). Also, in the coating composition not containing particles or having an average particle diameter of less than 1.0 μm, the value of μS + μK was not good, and the smooth touch was inferior to that of Examples 7 to 14 (Comparative Examples 8 and 9).

[0114]

Table 4

[0115] Consideration of Examples 15 to 17 and Comparative Examples 11 to 15 In Table 4, the coating composition containing a (meth)acrylic resin having a polysiloxane skeleton and particles with an average particle diameter of 1.0 μm or more and 100.0 μm or less had a good value of μS + μK, and a smooth touch was obtained when touching the coating film (Examples 15 to 17). On the other hand, the coating composition not containing a (meth)acrylic resin having a polysiloxane skeleton did not have a good value of μS + μK, and the smooth touch was inferior to that of Examples 15 to 17 (Comparative Examples 11, 12, and 15). Among them, in Comparative Example 12, stickiness occurred and a suitable coating film could not be obtained (note that in Comparative Example 12 and Example 15, the content of the structural unit having a polysiloxane skeleton contained in the coating composition is the same). Also, in the coating composition not containing particles or having an average particle diameter of less than 1.0 μm, the value of μS + μK was not good, and the smooth touch was inferior to that of Examples 15 to 17 (Comparative Examples 13 and 14).

Claims

1. a (meth)acrylic resin having a hydroxy group; a polyisocyanate compound; A coating composition comprising particles having an average particle diameter of 1.0 μm or more and 100.0 μm or less, the (meth)acrylic resin contains a structural unit derived from a (meth)acrylic acid and / or (meth)acrylic acid ester monomer and a structural unit having a polysiloxane skeleton, the content of the particles in the coating composition is 11 to 40% by mass relative to 100% by mass of the total solid content of the coating composition; A coating composition, wherein the content of the structural unit having a polysiloxane skeleton is 0.1% by mass or more and 20% by mass or less, relative to 100% by mass of the total solids content of the coating composition.

2. The coating composition of claim 1, The paint composition is such that the martensitic hardness measured under the following [Martensitic Hardness Measurement Conditions] of the coating film formed under the conditions described in the following [Coating Film Formation Conditions] is 1 N / mm ２ or more and 200 N / mm ２ or less. [Coating film formation conditions] The coating composition is applied to an acrylonitrile / butadiene / styrene copolymer synthetic resin substrate by air spraying, and the coated substrate is heated at 80°C for 60 minutes. After heating, the substrate is allowed to stand at 25°C and a relative humidity of 50% for 4 weeks to obtain a coating film having a thickness of 20 μm. [Martens hardness measurement conditions] The coating film formed under the above-mentioned [Coating film formation conditions] is used to measure the Martens hardness by pressing a Vickers indenter with a load of 4 mN into the coating film for 20 seconds using a microhardness tester at 23°C and a relative humidity of 50%. The Martens hardness is calculated by the following formula, where Fmax is the maximum test force and Hmax is the indentation depth at Fmax. Martens hardness (N / mm ２ )=Fmax / (26.43×(Hmax) ２ )

3. The coating composition according to claim 2, [[ID=]]When the static friction coefficient measured under the conditions described in the following [Coefficient of Friction Measurement Conditions] of the coating film formed under the conditions described in the [Coating Film Formation Conditions] is μS and the average kinetic friction coefficient is μK, when the martensitic hardness is 30 N / mm ２ In the following cases, the value of μS + μK is 1.8 or less, and when the martensitic hardness is greater than 30 N / mm ２ In the case where it is larger, the value of μS + μK is 1.4 or less, a coating composition. [Friction coefficient measurement conditions] Using the coating film formed under the above [Coating Film Formation Conditions], the coating film is mounted on a static and dynamic friction coefficient measuring machine under the conditions of 23°C and a relative humidity of 50%. A tactile contact element attached to the measuring machine is brought into contact with the coating film under the condition of a contact area of 1.5 cm ２ . The static friction coefficient (μS) and the average dynamic friction coefficient (μK) are measured by moving the tactile contact element 30 mm at a speed of 30 mm / s while applying a load of 10 g. The maximum value of the friction coefficient measured in the range where the moving distance of the tactile contact element is 0 mm or more and less than 10 mm is defined as the static friction coefficient (μS), and the average value of the measured values of the friction coefficient measured in the range where the moving distance of the tactile contact element is 10 mm or more and 25 mm or less is defined as the average dynamic friction coefficient (μK).

4. The coating composition according to any one of claims 1 to 3, A coating composition for glass transition temperature measurement, obtained by removing the particles from the coating composition, has a glass transition temperature (°C) of -30°C or higher and 90°C or lower, measured under the conditions described in [Conditions for Glass Transition Temperature Measurement] below. [Glass transition temperature measurement conditions] The coating composition for glass transition temperature measurement was applied to a polypropylene substrate by air spray, the coated substrate was heated at 80°C for 60 minutes, and then left to stand at 25°C and 50% relative humidity for 4 weeks to obtain a coating film with a thickness of 50 μm. The coating film was peeled off from the substrate and cut into test pieces 5 mm wide and 50 mm long. Using the test piece, the maximum value of the loss tangent tanδmax when measuring the dynamic viscoelasticity at a frequency of 1.0 Hz and a temperature range of -50 to 180 °C under the conditions of 23 °C and a relative humidity of 50% is defined as the glass transition temperature (°C).

5. The coating composition according to any one of Claims 1 to 4, wherein the arithmetic mean roughness (Ra) measured by the following [Arithmetic Mean Roughness Measurement Method] of the coating film formed under the conditions described in the following [Coating Film Formation Conditions] is 0.1 μm or more and 10.0 μm or less, the coating composition. [Coating Film Formation Conditions] The coating composition is sprayed onto an acrylonitrile / butadiene / styrene copolymer synthetic resin substrate by air spraying, the coated substrate is heated at 80 °C for 60 minutes, and after heating, it is left standing for 4 weeks under the conditions of 25 °C and a relative humidity of 50% to obtain a coating film with a thickness of 20 μm. [Arithmetic Mean Roughness Measurement Method] Using the coating film formed under the above [Coating Film Formation Conditions], in accordance with the method specified in JIS B0633:2001, using a surface roughness measuring instrument, a stylus with a radius of 2 μm is used, and the arithmetic mean roughness (Ra) is measured under the conditions of a moving speed of 0.5 mm / s, 23 °C, and a relative humidity of 50%.

6. The coating composition according to any one of Claims 1 to 5, wherein the 85° gloss value measured by the method specified in JIS Z8741:1997 under the conditions of 23 °C and a relative humidity of 50% of the coating film formed under the conditions described in the following [Coating Film Formation Conditions] is 3 or more and 90 or less, the coating composition. [Coating Film Formation Conditions] The coating composition is sprayed onto an acrylonitrile / butadiene / styrene copolymer synthetic resin substrate by air spraying, the coated substrate is heated at 80 °C for 60 minutes, and after heating, it is left standing for 4 weeks under the conditions of 25 °C and a relative humidity of 50% to obtain a coating film with a thickness of 20 μm.

7. The coating composition according to any one of Claims 1 to 6, wherein the content of the (meth)acrylic resin is 1% by mass or more and 80% by mass or less based on 100% by mass of the total solid content of the coating composition, the coating composition.

8. The coating composition according to any one of Claims 1 to 7, further comprising a polyol, the coating composition.

9. The coating composition according to Claim 8, wherein the polyol contains a carbonate diol, the coating composition.

10. The coating composition according to any one of Claims 1 to 9, A paint composition in which the particles are composed of one or more selected from silica particles, acrylic particles, urethane particles, and crosslinked polyacrylic acid particles.

11. The paint composition according to any one of Claims 1 to 10, A paint composition in which the number average molecular weight (Mn) of the structural unit having the polysiloxane skeleton in the (meth)acrylic resin is 500 or more and 20,000 or less.

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