Method for producing polyurethane coating film and coating composition

Abstract

To provide a method for producing a polyurethane coating film capable of obtaining a coating film excellent in physical properties and to provide a coating composition capable of obtaining a coating film excellent in physical properties.SOLUTION: There is provided a method for producing a polyurethane coating film which comprises: a mixing step of mixing a component (A): a polyol composition and a component (B): an isocyanate composition to obtain a coating composition; an application step of applying the coating composition; and a drying step of drying the applied coating composition to obtain a coating film, wherein a drying time in the drying step is set within 60 minutes after the application. In addition, the coating composition comprises a component (A): a polyol composition and a component (B): an isocyanate composition, wherein a baking time (drying time) until any finger mark is not left in finger touch evaluation is within 60 minutes.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] Conventionally, polyurethane resins have been used in a wide range of applications, such as synthetic leather, artificial leather, adhesives, furniture paints, and automotive paints. Among the raw materials for polyurethane resins, polyethers, polyesters, and polycarbonates are used as polyol components to be reacted with isocyanates. However, in recent years, there has been an increasing demand for polyurethane resins with improved resistance, such as heat resistance, weather resistance, hydrolysis resistance, solvent resistance, sunscreen resistance, and scratch resistance.

[0003] In general, it is known that polyurethane resins using polycarbonate diol as a polyol component are superior in wet heat resistance, solvent resistance, sunscreen resistance, scratch resistance, etc., to polyurethane resins using polyether or polyester. For example, Patent Document 1 discloses a polycarbonate diol using 1,5-pentanediol and 1,6-hexanediol as diol components. In addition, for example, Patent Document 2 discloses a polycarbonate diol using 1,4-butanediol and 1,6-hexanediol. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2001 / 90213 [Patent Document 2] International Publication No. 2009 / 063767 Summary of the Invention [Problem to be solved by the invention]

[0005] However, even if a coating composition using polycarbonate diol is used, the expected coating film properties may not be obtained depending on the curing conditions of the coating composition. The above Patent Documents 1 and 2 do not mention the appropriate curing conditions, and there is still room for improvement.

[0006] Therefore, an object of the present invention is to provide a method for producing a polyurethane coating film by which a coating film having excellent physical properties can be obtained, and a coating composition by which a coating film having excellent physical properties can be obtained. [Means for solving the problem]

[0007] As a result of extensive research to solve the above problems, the inventors have found that a coating film having excellent physical properties can be obtained by setting the drying time during formation of the coating film within a specific range, which led to the creation of the present invention.

[0008] That is, the present invention is configured as follows. [1] a mixing step of mixing the (A) component: a polyol composition and the (B) component: an isocyanate composition to obtain a coating composition; A coating step of coating the coating composition; A drying step of drying the applied coating composition to obtain a coating film, A method for producing a polyurethane coating film, wherein the drying time in the drying step is within 60 minutes after coating. [2] The method for producing a polyurethane coating film according to [1], wherein the component (A) has a structure represented by the following (AI): [ka] (In formula (AI), R 1 is a divalent linear, branched or cyclic aliphatic hydrocarbon group having 2 to 20 carbon atoms, or an aromatic hydrocarbon group. 1 may be the same or different. a is a number from 1 to 50.) [3] The method for producing a polyurethane coating film according to [2], wherein the component (A) contains 50% by mass or more and 95% by mass or less of the structure represented by (AI). [4] The method for producing a polyurethane coating film according to any one of [1] to [3], wherein the component (A) has a structure represented by the following general formula (I): [ka] (In general formula (I), R 11 is a divalent linear, branched or cyclic aliphatic hydrocarbon group having 2 to 20 carbon atoms, or an aromatic hydrocarbon group. 11 may be the same or different. n11 is a number between 7 and 70.) [5] The method for producing a polyurethane coating film according to [4], wherein the component (A) contains 5% by mass or more and 50% by mass or less of the structure represented by the general formula (I). [6] The method for producing a polyurethane coating film according to [4] or [5], wherein the structure represented by general formula (I) is a polyoxyethylene structure. [7] The method for producing a polyurethane coating film according to [4] or [5], wherein the content of oxy 1-methylethylene groups is from 10% by mass to 100% by mass, and the content of oxyethylene groups is from 0% by mass to 90% by mass, relative to the total mass of the structure represented by general formula (I). [8] The method for producing a polyurethane coating film according to any one of [1] to [7], wherein the hydroxyl value of the component (A) is 10 to 400 mgKOH / g. [9] The method for producing a polyurethane coating film according to any one of [1] to [8], wherein the average NCO functionality of the component (B) is 2.0 or more.

[10] The method for producing a polyurethane coating film according to any one of [1] to [9], wherein the number of moles of hydroxyl groups (OH groups) contained in the component (A) and the number of moles of isocyanate groups (NCO groups) contained in the component (B) satisfy the relationship of the following formula 1: Molar number of NCO groups / Molar number of OH groups = 0.2 to 7.0 (Equation 1)

[11] A coating composition comprising a component (A): a polyol composition and a component (B): an isocyanate composition, the baking time (drying time) until no finger mark is left in the following finger touch evaluation being within 60 minutes; [Touch evaluation] A coating composition is applied to a polycarbonate plate (2 mm x 70 mm x 150 mm) so that the dry film thickness is 40 μm, and the applied coating composition is baked at 60°C to obtain a polyurethane coating film. The baking time (drying time) until no finger marks remain on the surface after application is measured.

[12] The coating composition according to

[11] , wherein the number of moles of hydroxyl groups (OH groups) contained in the component (A) and the number of moles of isocyanate groups (NCO groups) contained in the component (B) satisfy the relationship of the following formula 1. Molar number of NCO groups / Molar number of OH groups = 0.2 to 7.0 (Equation 1)

[13] The coating composition according to

[11] or

[12] , wherein the hydroxyl value of the component (A) is 10 to 400 mgKOH / g.

[14] The coating composition according to any one of

[11] to

[13] , wherein the average NCO functionality of the component (B) is 2.0 or more.

[15] The coating composition according to any one of

[11] to

[14] , wherein the component (A) contains a carbonate group.

[16] The coating composition according to any one of

[11] to

[15] , wherein the component (A) has a structure represented by the following (AI): [ka] (In formula (AI), R 1 is a divalent linear, branched or cyclic aliphatic hydrocarbon group having 2 to 20 carbon atoms, or an aromatic hydrocarbon group. 1 may be the same or different. a is a number from 1 to 50.)

[17] The coating composition according to any one of

[11] to

[16] , wherein the component (A) contains the following component (A1): Component (A1): A polycarbonate diol composition containing a structure represented by the following general formula (I) and a polycarbonate structure represented by the following formula (AI), both ends of which are hydroxyl groups and have a hydroxyl value of 10 to 400 mgKOH / g, in which the content of the structure represented by the following general formula (I) is 5% by mass or more and 50% by mass or less, and the content of the polycarbonate structure represented by the following formula (AI) is 50% by mass or more and 95% by mass or less, based on the total mass of the structure represented by the following general formula (I) and the polycarbonate structure represented by the following formula (AI). [ka] (In general formula (I), R 11 is a divalent linear, branched or cyclic aliphatic hydrocarbon group having 2 to 20 carbon atoms, or an aromatic hydrocarbon group. 11 may be the same or different. n11 is a number between 7 and 70.) [ka] (In formula (AI), R 1 is a divalent linear, branched or cyclic aliphatic hydrocarbon group having 2 to 20 carbon atoms, or an aromatic hydrocarbon group. 1 may be the same or different. a is a number from 1 to 50.)

[18] The coating composition according to

[17] , wherein the structure represented by the general formula (I) is a polyoxyethylene structure.

[19] The coating composition according to

[17] , wherein the content of oxy 1-methylethylene groups is 10% by mass or more and 100% by mass or less, and the content of oxyethylene groups is 0% by mass or more and 90% by mass or less, relative to the total mass of the structure represented by the general formula (I).

[20] The coating composition according to any one of

[11] to

[19] , wherein the coating composition is a solvent-based coating composition. [twenty one] The coating composition according to any one of

[11] to

[19] , wherein the coating composition is a water-based coating composition. [twenty two] The coating composition according to any one of

[11] to

[19] , wherein the coating composition is a solventless coating composition. [twenty three] A coating film obtained from the coating composition according to any one of

[11] to

[22] . Effect of the Invention

[0009] According to the present invention, a coating film having excellent physical properties can be obtained. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention (hereinafter, referred to as "the present embodiment") will be described in detail. Note that the present invention is not limited to the following description, and can be modified in various ways within the scope of the present invention.

[0011] <Method of manufacturing polyurethane coating film> The method for producing a polyurethane coating film according to the present embodiment includes the steps of: a mixing step of mixing the (A) component: a polyol composition and the (B) component: an isocyanate composition to obtain a coating composition; A coating step of coating the coating composition; A drying step of drying the applied coating composition to obtain a coating film, The drying time in the drying step is set to within 60 minutes after application.

[0012] The method for producing a polyurethane coating film of this embodiment includes such steps, and by controlling the drying time in the drying step within a specific range, a coating film having excellent physical properties can be obtained. Specifically, for example, when the coating composition is a transparent clear coating composition, a coating film having excellent chemical resistance, scratch resistance, and moist heat resistance can be obtained, and when the coating composition is a soft-feel coating composition containing a matting agent, a coating film having excellent sunscreen resistance and weather resistance can be obtained.

[0013] The reason why the coating film properties expected from the design of the coating composition can be obtained by controlling the drying time in the drying step within a specific range is not clear, but it is thought that the curing state of the coating film has a large effect. If the time until the drying is completed, that is, the time until the coating film is cured, is too long, the isocyanate group in the isocyanate composition, which is the curing agent, disappears mainly due to the influence of moisture. In particular, the surface of the coating film is greatly affected by these influences because it is the first in the coating film structure to come into contact with moisture.

[0014] On the other hand, by controlling the drying time in the drying step within a specific range, the coating surface hardens well within an appropriate time, and most of the isocyanate groups in the isocyanate composition, which is a curing agent, react with the hydroxyl groups in the polyol composition, which is the main component, before being lost by moisture, so that it is possible to obtain the coating film properties expected from the design of the paint composition.

[0015] The cured state of the coating surface can be judged by finger touch evaluation described in the Examples below.

[0016] The method for controlling the drying time in the drying step within a specific range is not particularly limited, but examples thereof include a method for adjusting the amount of catalyst added to the coating composition and a method for appropriately selecting the type of polyol composition (base) and isocyanate composition (curing agent). Specifically, the more the amount of catalyst added, the shorter the drying time can be, and the more the number of functional groups in the polyol composition (base) and / or isocyanate composition (curing agent) is, the shorter the drying time can be.

[0017] [Mixing process] In the method for producing a polyurethane coating film of this embodiment, the mixing step is a step of mixing the above-mentioned (A) component, the above-mentioned (B) component, and, if necessary, the below-mentioned (C) component: a solvent and / or (D) component: other additives to obtain a coating composition.

[0018] The mixing method is not particularly limited, but examples thereof include a method in which the mixture is stirred using a stirrer or the like at a rotation speed of 50 rpm to 1000 rpm for 5 minutes to 60 minutes, and then degassed using a vacuum degasser.

[0019] [Coating process] In the method for producing a polyurethane coating film of this embodiment, the coating step is a step of applying the coating composition.

[0020] The method for applying the coating composition is not particularly limited, but for example, the components are mixed immediately before application and then applied to the substrate with a spray, roll, brush, etc. It is also possible to mix the components other than component (B), which is a curing agent, in advance, add component (B) immediately before application, mix uniformly, and then apply.

[0021] [Drying process] In the method for producing a polyurethane coating film of this embodiment, the drying step is a step of drying the applied coating composition to obtain a coating film.

[0022] The drying time in the drying step is preferably 5 to 55 minutes, more preferably 10 to 50 minutes after coating, even more preferably 15 to 45 minutes after coating, and even more preferably 20 to 30 minutes after coating. If the drying time is within the above range, a coating film with even more excellent physical properties can be obtained.

[0023] The drying temperature in the drying step is preferably 40°C to 200°C, more preferably 50°C to 175°C, even more preferably 60°C to 150°C, even more preferably 60°C to 120°C, and particularly preferably 60°C to 100°C.

[0024] The drying method in the drying step is not particularly limited, but examples thereof include natural drying, forced drying, and heat drying.

[0025] In the method for producing a polyurethane coating film of the present embodiment, the thickness of the coating film obtained after drying is preferably 1 μm to 100 μm, more preferably 2 μm to 90 μm, even more preferably 3 μm to 80 μm, even more preferably 5 μm to 50 μm, and particularly preferably 10 μm to 50 μm.

[0026] <Paint composition> The coating composition of this embodiment contains component (A): a polyol composition and component (B): an isocyanate composition, and the baking time (drying time) until no finger mark is left in the finger touch evaluation described below is within 60 minutes. [Touch evaluation] A coating composition is applied to a polycarbonate plate (2 mm x 70 mm x 150 mm) so that the dry film thickness is 40 μm, and the applied coating composition is baked at 60°C to obtain a polyurethane coating film. The baking time (drying time) until no finger marks remain on the surface after application is measured.

[0027] The coating composition containing the (A) component: polyol composition and the (B) component: isocyanate composition is not particularly limited, but examples thereof include one-component coatings and two-component coatings. The one-component coatings are not particularly limited, but examples thereof include thermoplastic polyurethane coatings, polyurethane dispersion coatings, and coatings using blocked isocyanates. The two-component coatings are not particularly limited, but examples thereof include coatings in which a polyol composition and an isocyanate composition are mixed immediately before coating.

[0028] The coating composition of this embodiment contains the (A) component and the (B) component, and the baking time (drying time) until no finger mark is left in the above-mentioned finger touch evaluation is within the above-mentioned specific range, so that a coating film with excellent physical properties can be formed. Specifically, for example, when the coating composition is a transparent clear coating composition, a coating film with excellent chemical resistance, scratch resistance, and moist heat resistance can be obtained, and, for example, when the coating composition is a soft feel coating composition containing a matting agent, a coating film with excellent sunscreen resistance and weather resistance can be obtained.

[0029] The coating composition of this embodiment has a baking time (drying time) until no finger mark is left in the above finger touch evaluation of 5 to 55 minutes, more preferably 10 to 50 minutes, even more preferably 15 to 45 minutes, and even more preferably 20 to 30 minutes.

[0030] In the coating composition of this embodiment, the ratio of the number of moles of hydroxyl groups (OH groups) contained in component (A) to the number of moles of isocyanate groups (NCO groups) contained in component (B) (number of moles of NCO groups / number of moles of OH groups) is preferably 0.2 to 7.0, more preferably 0.5 to 5.0, even more preferably 0.8 to 3.0, even more preferably 0.8 to 2.5, and particularly preferably 0.8 to 2.0.

[0031] Each component will be described in detail below. <Component (A): Polyol Composition> The polyol composition (component (A)) contained in the coating composition of this embodiment has a hydroxyl group that reacts with an isocyanate group. The hydroxyl value of the polyol composition is preferably 10 to 400 mgKOH / g, more preferably 20 to 300 mgKOH / g, and even more preferably 30 to 250 mgKOH / g. The hydroxyl value of the polyol composition can be calculated using the method described in the examples below.

[0032] Examples of the component (A) include, but are not limited to, polyester polyols, polyether polyols, acrylic polyols, polyolefin polyols, fluorine polyols, polycarbonate polyols, and the like.

[0033] [Polyester polyol] The polyester polyol can be obtained, for example, by subjecting a dibasic acid, or a mixture of two or more kinds, and a polyhydric alcohol, or a mixture of two or more kinds, to a condensation reaction.

[0034] The dibasic acid is not particularly limited, but examples thereof include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid.

[0035] The polyhydric alcohol is not particularly limited, but examples thereof include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, cyclohexanediol, trimethylolpropane, glycerin, pentaerythritol, 2-methylolpropanediol, and ethoxylated trimethylolpropane.

[0036] There are no particular limitations on the specific method for producing the polyester polyol. For example, the above components are mixed and heated at about 160 to 220° C. to carry out a condensation reaction.

[0037] Further, for example, polycaprolactones obtained by ring-opening polymerization of lactones such as ε-caprolactone with polyhydric alcohols can also be used as polyester polyols.

[0038] The polyester polyol obtained by the above-mentioned production method can be modified using an aromatic diisocyanate, an aliphatic diisocyanate, an alicyclic diisocyanate, a compound obtained therefrom, etc. Among them, from the viewpoint of the weather resistance and yellowing resistance of the obtained coating film, it is preferable to modify the polyester polyol using an aliphatic diisocyanate, an alicyclic diisocyanate, or a compound obtained therefrom.

[0039] When the coating composition of the present embodiment contains a solvent with a high water content, some of the carboxylic acids derived from the dibasic acids in the polyester polyol can be left to remain and neutralized with a base such as an amine or ammonia, thereby converting the polyester polyol into a water-soluble or water-dispersible resin.

[0040] [Polyether polyol] The polyether polyol can be obtained, for example, by using any one of the following methods (1) to (3), although the method is not particularly limited.

[0041] (1) A method in which an alkylene oxide or a mixture of alkylene oxides is randomly or block-added to a polyhydric hydroxy compound or a mixture of polyhydric hydroxy compounds using a catalyst to obtain polyether polyols. The catalyst is not particularly limited, but examples thereof include hydroxides (lithium, sodium, potassium, etc.), strong basic catalysts (alcoholates, alkylamines, etc.), composite metal cyanide complexes (metal porphyrins, zinc hexacyanocobaltate complexes, etc.), and the like. The alkylene oxide is not particularly limited, but examples thereof include ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and styrene oxide.

[0042] (2) A method in which a polyamine compound is reacted with an alkylene oxide to obtain a polyether polyol. The polyamine compound is not particularly limited, but examples thereof include ethylenediamines. Examples of the alkylene oxide include the same as those exemplified in (1).

[0043] (3) A method in which the polyether polyols obtained by (1) or (2) are used as a medium to polymerize acrylamide or the like to obtain so-called polymer polyols.

[0044] The polyhydric hydroxy compound is not particularly limited, but examples thereof include the following compounds (i) to (vi).

[0045] (i) Diglycerin, ditrimethylolpropane, pentaerythritol, dipentaerythritol, etc.

[0046] (ii) Sugar alcohol compounds such as erythritol, D-threitol, L-arabinitol, ribitol, xylitol, sorbitol, mannitol, galactitol, and rhamnitol.

[0047] (iii) Monosaccharides such as arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose, and ribosaccharides.

[0048] (iv) Disaccharides such as trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, and melibiose.

[0049] (v) Trisaccharides such as raffinose, gentianose, and melezitose.

[0050] (vi) Tetrasaccharides such as stachyose.

[0051] [Acrylic polyol] The acrylic polyol is not particularly limited, but can be obtained, for example, by polymerizing only a polymerizable monomer having one or more active hydrogens in one molecule, or by copolymerizing a polymerizable monomer having one or more active hydrogens in one molecule with, as necessary, another monomer copolymerizable with the polymerizable monomer.

[0052] The polymerizable monomer having one or more active hydrogens in one molecule is not particularly limited, but examples thereof include the following (i) to (vi). These may be used alone or in combination of two or more kinds.

[0053] (i) Acrylic esters having active hydrogen, such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxybutyl acrylate.

[0054] (ii) Methacrylic acid esters having active hydrogen, such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate.

[0055] (iii) (meth)acrylic acid esters having polyvalent active hydrogen, such as (meth)acrylic acid monoesters of triols such as glycerin and trimethylolpropane.

[0056] (iv) Monoethers of polyether polyols (for example, polyethylene glycol, polypropylene glycol, polybutylene glycol, etc.) and the above-mentioned (meth)acrylic acid esters having active hydrogen.

[0057] (v) Adducts of glycidyl (meth)acrylate with monobasic acids (eg, acetic acid, propionic acid, p-tert-butylbenzoic acid, etc.).

[0058] (vi) Adducts obtained by ring-opening polymerization of lactones (for example, ε-caprolactam, γ-valerolactone, etc.) with the active hydrogen of the above-mentioned (meth)acrylic acid esters having active hydrogen.

[0059] The other monomers copolymerizable with the polymerizable monomers are not particularly limited, but include, for example, the following (i) to (iv). These may be used alone or in combination of two or more.

[0060] (i) (Meth)acrylic acid esters such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, and glycidyl methacrylate.

[0061] (ii) acrylic acid, methacrylic acid, maleic acid, itaconic acid, etc., unsaturated amides (acrylamide, N-methylol acrylamide, diacetone acrylamide, etc., and unsaturated carboxylic acids.

[0062] (iii) Vinyl monomers having a hydrolyzable silyl group, such as vinyltrimethoxysilane, vinylmethyldimethoxysilane, and γ-(meth)acryloxypropyltrimethoxysilane.

[0063] (iv) Other polymerizable monomers such as styrene, vinyl toluene, vinyl acetate, acrylonitrile, dibutyl fumarate, etc.

[0064] The specific method for producing the acrylic polyol is not particularly limited. For example, the above-mentioned monomers are solution polymerized in the presence of a radical polymerization initiator such as a known peroxide or an azo compound, and the resulting solution is diluted with an organic solvent or the like as necessary to obtain the acrylic polyol.

[0065] When the coating composition of the present embodiment contains a solvent with a high water content, it can be produced by a known method such as a method of solution polymerization of the above-mentioned monomers and converting them into a water layer, or emulsion polymerization. In this case, the acidic moiety of a carboxylic acid-containing monomer such as acrylic acid or methacrylic acid or a sulfonic acid-containing monomer can be neutralized with an amine or ammonia to impart water solubility or water dispersibility to the acrylic polyol.

[0066] [Polyolefin polyol] The polyolefin polyol is not particularly limited, but examples thereof include polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene having two or more hydroxyl groups, polyisoprene having two or more hydroxyl groups, and hydrogenated polyisoprene having two or more hydroxyl groups.

[0067] Moreover, the number of hydroxyl groups statistically possessed by one molecule of the polyolefin polyol (hereinafter sometimes referred to as the "average number of hydroxyl groups") is preferably 2 or more.

[0068] [Fluoropolyol] In this specification, "fluorine polyol" means a polyol containing fluorine in the molecule.Specific examples of fluorine polyols include, but are not limited to, copolymers of fluoroolefins, cyclovinyl ethers, hydroxyalkyl vinyl ethers, monocarboxylic acid vinyl esters, etc., as disclosed in JP-A-57-34107 (Reference 1) and JP-A-61-275311 (Reference 2), etc.

[0069] [Polycarbonate polyol] The polycarbonate polyol is not particularly limited, but can be obtained, for example, by a condensation reaction between a carbonate compound and a polyol or a polyhydric alcohol, either alone or in a mixture of two or more kinds.

[0070] The carbonate compound is the same as the carbonate compound described below.

[0071] The polyol is not particularly limited, but examples thereof include the above-mentioned polyester polyol, polyether polyol, acrylic polyol, polyolefin polyol, and fluorine polyol.

[0072] The polyhydric alcohol is not particularly limited, and examples thereof include a diol compound, trimethylolpropane, pentaerythritol, glycerin, etc. The diol compound is the same as the diol compound described below.

[0073] The specific production method of the polycarbonate polyol is the same as the production conditions of the polycarbonate diol (II-1) described later.

[0074] In addition, it is preferable that the component (A) contains a carbonate group.

[0075] The component (A) may have a structure represented by the following (AI): [ka] (In formula (AI), R 1 is a divalent linear, branched or cyclic aliphatic hydrocarbon group having 2 to 20 carbon atoms, or an aromatic hydrocarbon group. 1 may be the same or different. a is a number from 1 to 50.)

[0076] Next, the details of the structure (AI) will be described below. (R 1 ) In general formula (I), R 1 is a divalent linear, branched or cyclic aliphatic hydrocarbon group having 2 to 20 carbon atoms, or an aromatic hydrocarbon group. 1 may be the same as or different from each other.

[0077] R 1The divalent linear aliphatic hydrocarbon group in has 2 or more and 20 or less carbon atoms, preferably 3 or more and 12 or less carbon atoms, and more preferably 3 or more and 10 or less carbon atoms.

[0078] R 1 The divalent linear aliphatic hydrocarbon group in is not particularly limited, and examples thereof include an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, etc. Among these, from the viewpoint of versatility, a propylene group, a butylene group, a pentylene group, a hexylene group, a nonylene group, and a decylene group are preferred.

[0079] R 1 The divalent branched aliphatic hydrocarbon group in has 3 or more and 20 or less carbon atoms, preferably 3 or more and 12 or less carbon atoms, and more preferably 3 or more and 10 or less carbon atoms.

[0080] R 1 Specific examples of the divalent branched aliphatic hydrocarbon group in the formula (I) include, but are not limited to, isopropylene, isobutylene, tert-butylene, isopentylene, 2,2-dimethyltrimethylene, isohexylene, isoheptylene, isooctylene, etc. Among these, from the viewpoint of versatility, isopropylene, isobutylene, isopentylene, 2,2-dimethyltrimethylene, and isohexylene are preferred.

[0081] R 1 The divalent cyclic aliphatic hydrocarbon group in has 3 or more and 20 or less carbon atoms, preferably 6 or more and 15 or less carbon atoms, and more preferably 6 or more and 10 or less carbon atoms.

[0082] R 1 Specific examples of the divalent alicyclic hydrocarbon group in the formula (I) include, but are not limited to, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, and a cycloheptylene group.

[0083] R 1The divalent aromatic hydrocarbon group in has 6 or more and 20 or less carbon atoms, preferably 6 or more and 15 or less, and more preferably 6 or more and 12 or less carbon atoms.

[0084] R 1 Specific examples of the divalent aromatic hydrocarbon group in the formula (I) include, but are not limited to, a phenylene group and a naphthylene group.

[0085] Among them, R 1 As the divalent alkyl group, a divalent linear, branched or cyclic aliphatic hydrocarbon group having 2 to 20 carbon atoms (i.e., an alkylene group) is preferable, a divalent linear aliphatic hydrocarbon group having 3 to 12 carbon atoms or a divalent branched aliphatic hydrocarbon group having 3 to 20 carbon atoms is more preferable, and a divalent linear aliphatic hydrocarbon group having 3 to 10 carbon atoms is even more preferable.

[0086] (a) In the general formula (AI), a represents a carbonate structure (-R 1 a represents the number of repetitions of the formula -O-CO-O-. a is a number from 1 to 50, preferably from 2 to 50, more preferably from 3 to 30, and further preferably from 4 to 20.

[0087] a can be determined by alkaline decomposition of the polycarbonate diol composition to extract a raw material diol component, and subjecting the component to GC-MS measurement, LC-MS measurement, and GPC measurement.

[0088] <Component (A1): Polycarbonate diol composition> The polyol composition (component (A)) preferably contains the following component (A1). Component (A1): A polycarbonate diol composition containing a structure represented by the following general formula (I) and a polycarbonate structure represented by the formula (AI), both ends of which are hydroxyl groups and have a hydroxyl value of 10 to 400 mgKOH / g, in which the content of the structure represented by the following general formula (I) is 5% by mass or more and 50% by mass or less, and the content of the polycarbonate structure represented by the formula (AI) is 50% by mass or more and 95% by mass or less, based on the total mass of the structure represented by the following general formula (I) and the polycarbonate structure represented by the formula (AI). [ka] (In general formula (I), R 11 is a divalent linear, branched or cyclic aliphatic hydrocarbon group having 2 to 20 carbon atoms, or an aromatic hydrocarbon group. 11 may be the same or different. n11 is a number between 7 and 70.)

[0089] In the coating composition of the present embodiment, when the (A) component contains the (A1) component, a coating film having even more excellent physical properties tends to be obtained. Specifically, for example, when the coating composition is a transparent clear coating composition, a coating film having excellent chemical resistance, scratch resistance, and moist heat resistance can be obtained, and when the coating composition is a soft-feel coating composition containing a matting agent, a coating film having excellent sunscreen resistance and weather resistance can be obtained.

[0090] The polycarbonate diol composition (component (A1)) contains a polycarbonate diol. This polycarbonate diol contains, in the molecular chain, a structure represented by the general formula (I) (hereinafter, sometimes referred to as "structure (I)") and a polycarbonate structure represented by the formula (AI) (hereinafter, sometimes referred to as "polycarbonate structure (AI)").

[0091] In addition, based on the total mass of the structure represented by general formula (I) and the polycarbonate structure represented by formula (AI), the content of the structure represented by general formula (I) is preferably 5 mass% or more and 50 mass% or less, and the content of the polycarbonate structure represented by formula (AI) is preferably 50 mass% or more and 95 mass% or less.

[0092] When the coating composition of the present embodiment has a content of the structure represented by general formula (I) within the above range, a coating film having even more excellent physical properties tends to be obtained.

[0093] The content of the structure represented by general formula (I) and the content of the polycarbonate structure represented by formula (AI) in the polycarbonate diol composition (component (A1)) can be measured, for example, by the following methods (1) to (4).

[0094] (1) The polycarbonate diol composition is subjected to alkaline hydrolysis in an ethanolic potassium hydroxide solution to regenerate the diol component. (2) Use phenolphthalein as an indicator and add hydrochloric acid to neutralize. (3) The precipitated salt is filtered off, and the filtrate is subjected to GPC measurement. (4) The concentration of the diol having hydroxyl groups at both ends of the structure represented by general formula (I) in the filtrate is determined from a separately prepared calibration curve. The mass of the diol having hydroxyl groups at both ends of the structure represented by general formula (I) is calculated from the concentration, and the value obtained by dividing the mass by the mass of the polycarbonate diol composition used in the alkaline hydrolysis is the content of the diol having hydroxyl groups at both ends of the structure represented by general formula (I).

[0095] The terminal structure of the structure represented by general formula (I) in the polycarbonate diol composition (component (A1)) is a terminal structure in which one terminal is bonded to a carbonate group (-O-CO-O-) and the other terminal is bonded to a hydroxyl group (-OH), a terminal structure in which both terminals are bonded to carbonate groups (-O-CO-O-), or a terminal structure in which both terminals are bonded to hydroxyl groups (-OH).

[0096] Furthermore, both ends of the molecule having the structure represented by general formula (I) in the polycarbonate diol composition (component (A1)) are hydroxyl groups.

[0097] The molecules having a polycarbonate structure contained in the polycarbonate diol composition (component (A1)) have hydroxyl groups at both ends. That is, the molecules having a polycarbonate structure contained in the polycarbonate diol composition (component (A1)) are polycarbonate diols. Due to impurities in various raw materials used in the production of the polycarbonate diol composition, terminal structures by-produced during the production of the polycarbonate diol composition, or for the purpose of controlling the urethane reaction rate and state in the use of the polycarbonate diol composition, some of the terminal hydroxyl groups may be converted to alkyl groups or aryl groups that do not react with isocyanate groups. In this embodiment, such cases are also taken into consideration, and the terminal groups of the polycarbonate diol include cases where 100 mol % of both ends are not strictly hydroxyl groups. From this viewpoint, the ratio of hydroxyl groups to the total molar amount of terminal groups is preferably 90 mol % or more, more preferably 95 mol % or more.

[0098] The both terminal structures of the polycarbonate diol contained in the polycarbonate diol composition can be confirmed, for example, in accordance with the method for measuring the primary terminal OH ratio described in Japanese Patent No. 3874664 (Reference 3).

[0099] However, as the solvent for recovering the fraction, in addition to ethanol, solvents such as tetrahydrofuran, acetone, and methanol can be used.

[0100] The hydroxyl value of the polycarbonate diol composition (component (A1)) is preferably 10 to 400 mgKOH / g, more preferably 20 to 300 mgKOH / g, and further preferably 30 to 250 mgKOH / g. The hydroxyl value can be calculated using the method described in the examples below.

[0101] When the hydroxyl value is equal to or more than the lower limit, the flexibility and low-temperature properties of the thermoplastic urethane obtained from the polycarbonate diol composition tend to be better. On the other hand, when the hydroxyl value is equal to or less than the upper limit, the molding processability of the thermoplastic urethane obtained from the polycarbonate diol composition tends to be better.

[0102] [Structure (I)] In the polycarbonate diol composition (component (A1)), the content of Structure (I) relative to the total mass of Structure (I) and the polycarbonate structure (AI) is preferably 5 mass% or more and 50 mass% or less, more preferably 5 mass% or more and 35 mass% or less, even more preferably 5 mass% or more and 20 mass% or less, and particularly preferably 5 mass% or more and 15 mass% or less.

[0103] When the content of Structure (I) is equal to or greater than the lower limit, a coating film having better scratch recovery properties can be obtained. When the content of Structure (I) is equal to or less than the upper limit, a coating film having better heat resistance can be obtained.

[0104] In the polycarbonate diol composition (component (A1)), the terminal structure of the structure (I) is a terminal structure in which one terminal is bonded to a carbonate group and the other terminal is bonded to a hydroxyl group, or a terminal structure in which both terminals are bonded to carbonate groups, or a terminal structure in which both terminals are bonded to hydroxyl groups.

[0105] In the polycarbonate diol composition (component (A1)), the terminal structure of the structure (I) may be a mixture of an terminal structure in which one terminal is bonded to a carbonate group and the other terminal is bonded to a hydroxyl group, and an terminal structure in which both terminals are bonded to carbonate groups.

[0106] Next, the structure (I) will be described in detail below. (R 11 ) In general formula (I), R 11is a divalent linear, branched or cyclic aliphatic hydrocarbon group having 2 to 20 carbon atoms, or an aromatic hydrocarbon group. 11 may be the same or different. Among them, R 11 are preferably identical to each other.

[0107] R 11 The divalent linear aliphatic hydrocarbon group in has 2 or more and 20 or less carbon atoms, preferably 2 or more and 12 or less carbon atoms, and more preferably 2 or more and 10 or less carbon atoms.

[0108] R 11 Specific examples of the divalent linear aliphatic hydrocarbon group in the formula (I) include, but are not limited to, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, and a dodecylene group.

[0109] R 11 The divalent branched aliphatic hydrocarbon group in has 3 or more and 20 or less carbon atoms, preferably 3 or more and 12 or less carbon atoms, and more preferably 3 or more and 10 or less carbon atoms.

[0110] R 11 Specific examples of the divalent branched aliphatic hydrocarbon group in the formula (I) include, but are not limited to, an isopropylene group, an isobutylene group, a tert-butylene group, an isopentylene group, a 2,2-dimethyltrimethylene group, an isohexylene group, an isoheptylene group, and an isooctylene group.

[0111] R 11 The divalent cyclic aliphatic hydrocarbon group in has 6 or more and 20 or less carbon atoms, preferably 6 or more and 15 or less carbon atoms, and more preferably 6 or more and 10 or less carbon atoms.

[0112] R 11Specific examples of the divalent cyclic aliphatic hydrocarbon group in the formula (I) include, but are not limited to, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, and a cycloheptylene group.

[0113] R 11 The divalent aromatic hydrocarbon group in has 6 or more and 20 or less carbon atoms, preferably 6 or more and 15 or less, and more preferably 6 or more and 12 or less carbon atoms.

[0114] R 11 Specific examples of the divalent aromatic hydrocarbon group in the formula (I) include, but are not limited to, a phenylene group and a naphthylene group.

[0115] Among them, R 11 As the divalent alkyl group, a divalent linear, branched or cyclic aliphatic hydrocarbon group having 2 to 20 carbon atoms (i.e., an alkylene group) is preferable, a divalent linear aliphatic hydrocarbon group having 2 to 12 carbon atoms or a divalent branched aliphatic hydrocarbon group having 3 to 20 carbon atoms is more preferable, and a divalent linear aliphatic hydrocarbon group having 2 to 10 carbon atoms is even more preferable.

[0116] (n11) In the general formula (I), n11 represents the structure (-R 11 n11 represents the number of repetitions of -O-). n11 is a number of 7 or more and 70 or less, preferably a number of 7 or more and 60 or less, and more preferably a number of 7 or more and 50 or less.

[0117] By making n11 equal to or greater than the lower limit, the amount of diol having hydroxyl groups at both ends of the structure represented by general formula (I) as the raw material can be reduced, and the water resistance and heat resistance of the coating film obtained using the polycarbonate diol composition (component (A1)) tend to be improved. Also, by making n11 equal to or less than the upper limit, the crystallinity and turbidity of the polycarbonate diol composition tend to be suppressed.

[0118] The above n11 can be determined by alkaline decomposition of the polycarbonate diol composition to extract the raw material diol component, and subjecting the component to GC-MS measurement, LC-MS measurement, and gel permeation chromatography (GPC) measurement.

[0119] Among these, the structure (I) is preferably a polyoxyalkylene structure.

[0120] Specific examples of preferred oxyalkylene groups contained in the structure (I) include, but are not limited to, oxyethylene groups, oxy1-methylethylene groups, oxytetramethylene groups, oxy2,2-dimethyltrimethylene groups, etc. Among these, oxyethylene groups and oxy1-methylethylene groups are preferred.

[0121] Furthermore, it is particularly preferred that the oxyalkylene group contained in structure (I) is a polyoxyethylene structure, a polyoxy1-methylethylene structure and / or a polyoxyethylene-polyoxy1-methylethylene structure, each of which is composed of an oxyethylene group and / or an oxy1-methylethylene group.

[0122] When Structure (I) contains an oxy 1-methylethylene group and / or an oxyethylene group, the content of the oxy 1-methylethylene group is preferably from 10% by mass to 100% by mass and the content of the oxyethylene group is preferably from 0% by mass to 90% by mass, more preferably from 30% by mass to 100% by mass and the content of the oxyethylene group is preferably from 0% by mass to 70% by mass, even more preferably from 50% by mass to 100% by mass and the content of the oxyethylene group is preferably from 0% by mass to 50% by mass, and particularly preferably from 70% by mass to 100% by mass and the content of the oxyethylene group is preferably from 0% by mass to 30% by mass.

[0123] When the structure (I) contains an oxytetramethylene group and / or an oxy2,2-dimethyltrimethylene group, the content of the oxytetramethylene group is preferably 5% by mass or more and 100% by mass or less, and the content of the oxy2,2-dimethyltrimethylene group is preferably 0% by mass or more and 95% by mass or less, more preferably 10% by mass or more and 100% by mass or less, and the content of the oxy2,2-dimethyltrimethylene group is more preferably 0% by mass or more and 90% by mass or less, and the content of the oxytetramethylene group is more preferably is 30% by mass or more and 100% by mass or less, and the content of oxy 2,2-dimethyltrimethylene groups is more preferably 0% by mass or more and 70% by mass or less, even more preferably the content of oxytetramethylene groups is 50% by mass or more and 100% by mass or less and the content of oxy 2,2-dimethyltrimethylene groups is 0% by mass or more and 50% by mass or less, and it is particularly preferably the content of oxytetramethylene groups is 70% by mass or more and 100% by mass or less and the content of oxy 2,2-dimethyltrimethylene groups is 0% by mass or more and 30% by mass or less.

[0124] [Polycarbonate structure (AI)] In the polycarbonate diol composition used in the present embodiment, the content of the polycarbonate structure (AI) relative to the total mass of the structure (I) and the polycarbonate structure (AI) is preferably 50% by mass or more and 95% by mass or less, more preferably 65% ​​by mass or more and 95% by mass or less, still more preferably 80% by mass or more and 95% by mass or less, and particularly preferably 85% by mass or more and 95% by mass or less.

[0125] By having the content of the polycarbonate structure (AI) be equal to or more than the above lower limit, a coating film that is more excellent in water resistance, heat resistance, chemical resistance, abrasion resistance, etc. is likely to be obtained. In addition, by having the content of the polycarbonate structure (AI) be equal to or less than the above upper limit, the compatibility of the polycarbonate diol composition with the polyether polyol is more excellent.

[0126] <Method for producing polycarbonate diol composition (component (A1))> The polycarbonate diol composition (component (A1)) can be obtained by carrying out an ester exchange reaction using an ether diol represented by the following general formula (I-1) (hereinafter, may be referred to as "ether diol (I-1)") and a polycarbonate diol represented by the following general formula (II-1) (hereinafter, may be referred to as "polycarbonate diol (II-1)"). [ka] (In general formula (I-1), R 111 is the above R 11 (n111 is the same as n11 above.) [ka] (In general formula (I-1), R 211 and R 212 are the above R 1 n211 is the same as above a.)

[0127] [Ether diol (I-1)] The ether diol (I-1) used in the production of the polycarbonate diol composition (component (A1)) may be any diol having a structure represented by the above general formula (I-1). Among them, the ether diol (I-1) is preferably a polyoxyalkylene diol. The ether diol (I-1) is commercially available in a variety of hydroxyl value products, and such commercially available products can also be used. Examples of commercially available ether diol (I-1) include polyoxyalkylene diols such as the "polyethylene glycol" series and "polytetramethylene oxide" series manufactured by Wako Pure Chemical Industries, Ltd., the "PTXG" series manufactured by Asahi Kasei Corporation, the "Sannyx" series and "Newpol" series manufactured by Sanyo Chemical Industries, Ltd., and the "Pronon" series manufactured by NOF Corporation.

[0128] The hydroxyl value of the ether diol (I-1) is not particularly limited, but is preferably 30 to 400 mgKOH / g, more preferably 50 to 200 mgKOH / g. When the hydroxyl value of the ether diol (I-1) used in the production is the above lower limit or more, the amount of the raw material ether diol (I-1) used can be further reduced. Furthermore, the water resistance and heat resistance of the coating film obtained from the polycarbonate diol composition tend to be further improved. When the hydroxyl value of the ether diol (I-1) used in the production is the above upper limit or less, the crystallinity and turbidity of the polycarbonate diol composition tend to be further suppressed.

[0129] [Polycarbonate diol (II-1)] The polycarbonate diol (II-1) used in the production of the polycarbonate diol composition (component (A1)) may be any one having a structure represented by the above general formula (II-1). The method for producing the polycarbonate diol (II-1) is not particularly limited, and a known method can be adopted. For example, the polycarbonate diol (II-1) can be obtained by reacting a carbonate compound with a diol compound in the presence of an ester exchange catalyst.

[0130] (Carbonate compounds) The carbonate compound used in the production of the polycarbonate diol (II-1) is not limited to the following, but examples thereof include alkylene carbonates, dialkyl carbonates, diaryl carbonates, and the like.

[0131] The alkylene carbonate is not particularly limited, but examples thereof include ethylene carbonate, trimethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, and 1,2-pentylene carbonate.

[0132] The dialkyl carbonate is not particularly limited, but examples thereof include dimethyl carbonate, diethyl carbonate, dipropyl carbonate, and dibutyl carbonate.

[0133] The diaryl carbonate is not particularly limited, but examples thereof include diphenyl carbonate.

[0134] Among them, the carbonate compound used in the production of the polycarbonate diol (II-1) is preferably an alkylene carbonate, and more preferably ethylene carbonate.

[0135] (Diol Compound) The diol compound used in the production of the polycarbonate diol (II-1) is not limited to the following, but examples thereof include linear diols, branched diols, cyclic diols, and diols having an aromatic ring.

[0136] The linear diol is not particularly limited, but examples thereof include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nanodiol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

[0137] The branched diol is not particularly limited, but examples thereof include 2-methyl-1,8-octanediol, neopentyl glycol, 2-ethyl-1,6-hexanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,4-dimethyl-1,5-pentanediol, and 2,4-diethyl-1,5-pentanediol.

[0138] The cyclic diol is not particularly limited, but examples thereof include 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 2-bis(4-hydroxycyclohexyl)-propane, and the like.

[0139] The diol having an aromatic ring is not particularly limited, but examples thereof include p-xylenediol, p-tetrachloroxylenediol, 1,4-bis(hydroxyethoxy)benzene, and 2,2-bis[(4-hydroxyethoxy)phenyl]propane.

[0140] Among these, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, or 1,10-decanediol is more preferred.

[0141] [Production conditions of polycarbonate diol composition (component (A1)) and polycarbonate diol (II-1)] In producing the raw material polycarbonate diol (II-1), a transesterification catalyst can be used. The catalyst can be selected from ordinary transesterification catalysts.

[0142] The transesterification catalyst is not particularly limited, but examples thereof include alkali metals and alkaline earth metals, as well as their alcoholates, hydrides, oxides, amides, hydroxides and salts.

[0143] The salts of alkali metals and alkaline earth metals are not particularly limited, but examples thereof include carbonates, nitrogen-containing borates, and basic salts with organic acids.

[0144] The alkali metal is not particularly limited, but examples thereof include lithium, sodium, and potassium.

[0145] The alkaline earth metal is not particularly limited, but examples thereof include magnesium, calcium, strontium, barium, and the like.

[0146] In addition, the transesterification catalyst using a metal other than an alkali metal or an alkaline earth metal is not particularly limited, but examples thereof include metals other than an alkali metal or an alkaline earth metal, as well as salts thereof, alcoholates thereof, and organic compounds containing the metals.

[0147] Specific examples of metals other than alkali metals and alkaline earth metals include, but are not limited to, aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, indium, tin, antimony, tungsten, rhenium, osmium, iridium, platinum, gold, thallium, lead, bismuth, and ytterbium.

[0148] These transesterification catalysts can be used alone or in combination of two or more.

[0149] Among them, as the transesterification reaction catalyst, one or more metals selected from the group consisting of sodium, potassium, magnesium, potassium, titanium, zirconium, tin, lead, and ytterbium, or salts thereof, alkoxides thereof, or organic compounds containing these metals are preferred, because the transesterification reaction to obtain a polycarbonate diol is carried out more satisfactorily and the effect on the urethane reaction is smaller when the obtained polycarbonate diol is used.

[0150] Moreover, the transesterification catalyst is more preferably one or more metals selected from the group consisting of magnesium, titanium, ytterbium, tin and zirconium.

[0151] Specific examples of preferred transesterification catalysts include lead compounds, titanium compounds, and magnesium compounds.

[0152] The lead compound is not particularly limited, but examples thereof include lead acetate trihydrate, tetraphenyl lead, and lead stearate.

[0153] The titanium compound is not particularly limited, but examples thereof include titanium tetra-n-butoxide, titanium tetra-n-propoxide, titanium tetraisopropoxide, and the like.

[0154] The magnesium compound is not particularly limited, but examples thereof include magnesium acetate, magnesium acetate tetrahydrate, and the like.

[0155] The amount of the transesterification catalyst used is preferably from 0.00001% by mass to 0.1% by mass, and more preferably from 0.0001% by mass to 0.05% by mass, based on the total mass of the raw materials.

[0156] When the heat treatment is performed following the production of polycarbonate diol, the transesterification catalyst used in the transesterification reaction is not consumed in the transesterification reaction, so the amount can be calculated based on the amount of the transesterification catalyst used. When a commercially available polycarbonate diol is used, the amount of metal in the transesterification catalyst contained in the polycarbonate diol can be measured by ICP (Inductively Coupled Plasma) emission spectroscopy.

[0157] The polycarbonate diol (II-1) used in the production of the polycarbonate diol composition (component (A1)) may contain a catalyst poison such as a phosphoric acid ester compound in order to deactivate the transesterification catalyst used in the production.

[0158] When the raw material polycarbonate diol (II-1) contains a catalyst poison of the transesterification catalyst used in its production, the transesterification reaction between the ether diol (I-1) and the polycarbonate diol (II-1) tends to be difficult to proceed. Therefore, when producing the polycarbonate diol composition (component (A1)), a necessary amount of the above-mentioned transesterification catalyst can be newly added.

[0159] On the other hand, when the raw material polycarbonate diol (II-1) does not contain a catalyst poison for the transesterification catalyst, the transesterification reaction in this embodiment usually tends to proceed easily. However, when it is desired to lower the reaction temperature or shorten the reaction time in the production process of the polycarbonate diol composition (component (A1)), a necessary amount of a new transesterification catalyst can be added. In this case, the same transesterification catalyst as that used in the production of the raw material polycarbonate diol (II-1) can be used.

[0160] The polycarbonate diol (II-1) used in the production of the polycarbonate diol composition (component (A1)) may be a homopolycarbonate diol obtained from one kind of diol compound, or a copolymer polycarbonate diol obtained from two or more kinds of diol compounds.

[0161] Any of the above-listed polycarbonate diols (II-1) can be used to obtain a polycarbonate diol composition (component (A1)) by transesterification with the ether diol (I-1).

[0162] However, for example, homogeneous polycarbonate diol obtained by using 1,6-hexanediol, which is widely used in the market, is usually solid at room temperature, and therefore, the polycarbonate diol composition (component (A1)) obtained by transesterification of the homogeneous polycarbonate diol with the ether diol (I-1) also tends to be solid at room temperature.

[0163] On the other hand, for example, a copolymer polycarbonate diol obtained by using two kinds of 1,5-pentanediol and 1,6-hexanediol is liquid at room temperature, and therefore, a polycarbonate diol composition (component (A1)) obtained by transesterification of the copolymer polycarbonate diol with an ether diol (I-1) also tends to be liquid at room temperature.

[0164] Therefore, from the viewpoint of ease of handling, it is often the case that the raw material polycarbonate diol is preferably one that is liquid at room temperature.

[0165] The hydroxyl value of the polycarbonate diol (II-1) used in producing the polycarbonate diol composition (component (A1)) is not particularly limited, but is preferably 20 to 300 mgKOH / g, and more preferably 30 to 250 mgKOH / g or less.

[0166] When the hydroxyl value of the polycarbonate diol (II-1) is equal to or greater than the lower limit, the performance expected of the polycarbonate diol tends to be improved. On the other hand, when the hydroxyl value of the polycarbonate diol (II-1) is equal to or less than the upper limit, the increase in viscosity of the polycarbonate diol composition (component (A1)) can be more effectively suppressed, and the handling property tends to be improved.

[0167] The polycarbonate diol composition (component (A1)) can also be produced by using an ether diol (I-1) as a diol and subjecting the ether diol (I-1) to a polycondensation reaction with a carbonate compound. However, in order to promote such a polycondensation reaction of the polycarbonate diol, it is usually necessary to heat the mixture at a high temperature for a long time. This may increase the possibility of undesired side reactions occurring or increase the workload when switching the product type.

[0168] From this viewpoint, the polycarbonate diol composition (component (A1)) is preferably produced by a transesterification reaction using an ether diol (I-1) and a polycarbonate diol (II-1) without using a polycondensation reaction using an ether diol (I-1) and a carbonate compound.

[0169] Specifically, the transesterification reaction can be carried out by mixing the ether diol (I-1) and the polycarbonate diol (II-1) and stirring the mixture while heating.

[0170] The temperature of the transesterification reaction is not particularly limited, but is preferably 120°C or higher and 250°C or lower, and more preferably 140°C or higher and 200°C or lower.

[0171] By setting the reaction temperature to the above lower limit, the transesterification reaction can be carried out in a shorter time, which is economically advantageous. By setting the reaction temperature to the above upper limit, the coloration of the resulting polycarbonate diol composition can be more effectively prevented.

[0172] The reaction pressure of the transesterification reaction is not particularly limited, but is preferably from normal pressure to 1 MPa. By setting the reaction pressure within the above range, the reaction can be carried out more easily. In addition, when using auxiliary raw materials, the transesterification reaction can be promoted more efficiently by applying a certain amount of pressure in consideration of the vapor pressure of these raw materials.

[0173] As a method for controlling the hydroxyl value of the polycarbonate diol composition (component (A1)), for example, it is preferable to select a raw material polycarbonate diol (II-1) having an appropriate hydroxyl value, or to carry out an ester exchange reaction in the presence of one or more kinds of ether diols (I-1) from the viewpoint of hydroxyl value adjustment.

[0174] The progress and completion of the transesterification reaction can be confirmed by GPC measurement. As the transesterification reaction proceeds, the peak derived from the raw material ether diol (I-1) becomes smaller over time, and when the peak disappears, it can be confirmed that the structure derived from the ether diol (I-1) is bonded to the end of the raw material polycarbonate diol (II-1) or inside the polymer chain.

[0175] In the method for producing the polycarbonate diol composition (component (A1)), a step of dehydrating the raw materials to be used may be carried out as a pretreatment prior to the above-mentioned transesterification reaction.

[0176] In the method for producing the polycarbonate diol composition (component (A1)), after the above-mentioned transesterification reaction, a step of adding the above-mentioned catalyst poison to the transesterification catalyst may be carried out as a post-treatment.

[0177] The coating composition of this embodiment can provide a coating film with excellent physical properties by containing the polycarbonate diol composition (component (A1)) as described above.

[0178] <Component (B): Isocyanate Composition> The isocyanate composition (component (B)) contained in the coating composition of this embodiment is not particularly limited as long as it acts as a curing agent for the coating composition, and one having an isocyanate group that reacts with an OH group is used. The average NCO functionality of the isocyanate composition (component (B)) is preferably 2.0 or more, more preferably 2.2 or more, even more preferably 2.5 or more, even more preferably 3.0 or more, particularly preferably 3.2 or more, and more particularly preferably 3.5 or more. The upper limit of the average NCO functionality of the isocyanate composition (component (B)) is not particularly limited, but is, for example, 7.0 or less.

[0179] In the coating composition of the present embodiment, when the average NCO functionality of the isocyanate composition (component (B)) is within the above range, a coating film having more excellent physical properties tends to be obtained. Specifically, for example, when the coating composition is a transparent clear coating composition, a coating film having more excellent chemical resistance, scratch resistance, and moist heat resistance can be obtained, and when the coating composition is a soft-feel coating composition containing a matting agent, a coating film having more excellent sunscreen resistance and weather resistance can be obtained.

[0180] The average NCO functionality can be confirmed in accordance with the method for determining the average isocyanate functionality described in Japanese Patent No. 6,538,363.

[0181] Examples of such component (B) include, but are not limited to, linear aliphatic diisocyanates, cyclic aliphatic diisocyanates, aromatic diisocyanates, and isocyanate compounds having three or more isocyanate groups, as well as isocyanurate-modified products and biuret-modified products of these isocyanate compounds.

[0182] The chain aliphatic diisocyanate is not particularly limited, but examples thereof include hexamethylene diisocyanate and trimethylhexamethylene diisocyanate.

[0183] The cyclic aliphatic diisocyanate is not particularly limited, but examples thereof include isophorone diisocyanate.

[0184] The aromatic diisocyanate is not particularly limited, but examples thereof include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, and naphthylene diisocyanate.

[0185] The isocyanate compound having three or more isocyanate groups is not particularly limited, but examples thereof include triphenylmethane-4,4'-4''-triisocyanate, 1,3,5-triisocyanatobenzene, 2,4,6-triisocyanatotoluene, and 4,4'-dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate.

[0186] The isocyanate compound may be a commercially available product or may be synthesized by a known method.

[0187] Commercially available isocyanate compounds include, for example, 24A-100, 22A-75P, TPA-100, TKA-100, P301-75E, D101, D201, 21S-75E, MFA-75B, MHG-80B, TUL-100, TLA-100, TSA-100, TSS-100, TSE-100, E402-80B, E405-80B, AE700-100, A201H, 17 Examples of such compounds include the "Duranate (product name)" series manufactured by Asahi Kasei Corporation, such as B-60P, TPA-B80E, MF-B60B, MF-K60B, SBB-70P, SBN-70D, E402-B80B, WB40-100, WT30-100, WT31-100, WB40-80D, WT20-100, WL70-100, WE50-100, WM44-L70G, and WT36-72PB.

[0188] By including the above-mentioned isocyanate composition (component (B)) in the coating composition of this embodiment, curing can be completed in the short time described above when drying after application of the coating composition (no finger marks are left in the finger touch evaluation described in the examples below), and a coating film with excellent physical properties can be obtained.

[0189] In the coating composition of this embodiment, the content of the isocyanate composition (component (B)) may be adjusted appropriately according to the molar amount of hydroxyl groups contained in the polyol composition (component (A)) which is the main component.

[0190] Specifically, the ratio of the number of moles of isocyanate groups contained in the isocyanate composition (component (B)) to the number of moles of hydroxyl groups contained in the polyol composition (component (A)) (hereinafter also referred to as "number of moles of NCO groups / number of moles of OH groups") can be, for example, 0.3 or more and 7.0 or less, for example, 0.5 or more and 5.0 or more, for example, 0.8 or more and 3.0 or less, 0.8 or more and 2.5 or less, or 0.8 or more and 2.0 or less.

[0191] When the mole number of NCO groups / mol number of OH groups is equal to or greater than the lower limit, a tougher coating film tends to be obtained. On the other hand, when the mole number of NCO groups / mol number of OH groups is equal to or less than the upper limit, the chemical resistance of the coating film tends to be improved.

[0192] <Component (C): Solvent> The coating composition of the present embodiment may contain a solvent (component (C)) in addition to the above-mentioned components (A) and (B). The solvent may be any solvent that functions as a solvent, and water or an organic solvent may be used depending on the coating system.

[0193] The organic solvent is not particularly limited, but examples thereof include amide-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, carbonate-based solvents, and aromatic hydrocarbon-based solvents.

[0194] The amide solvent is not particularly limited, but examples thereof include dimethylformamide, diethylformamide, dimethylacetamide, and N-methylpyrrolidone.

[0195] The sulfoxide solvent is not particularly limited, but examples thereof include dimethyl sulfoxide.

[0196] The ketone solvent is not particularly limited, but examples thereof include methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, and the like.

[0197] The ether solvent is not particularly limited, but examples thereof include tetrahydrofuran and dioxane.

[0198] The ester-based solvent is not particularly limited, but examples thereof include methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, and propylene glycol 1-monomethyl ether 2-acetate.

[0199] The carbonate ester solvent is not particularly limited, but examples thereof include dimethyl carbonate, diethyl carbonate, and propylene carbonate.

[0200] The aromatic hydrocarbon solvent is not particularly limited, but examples thereof include toluene and xylene.

[0201] These organic solvents may be used alone or as a mixed solvent of two or more kinds.

[0202] Among these, the solvent contained in the coating composition of the present embodiment is preferably at least one selected from the group consisting of water, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, propylene glycol 1-monomethyl ether 2-acetate, toluene, and xylene.

[0203] The content of the solvent (component (C)) in the coating composition of this embodiment can be, for example, 10 mass % or more and 90 mass % or less, for example, 15 mass % or more and 70 mass % or less, and for example, 20 mass % or more and 50 mass % or less, relative to the total mass of the coating composition.

[0204] The coating composition of the present embodiment is preferably a solvent-based coating composition containing the above-mentioned organic solvent.

[0205] The coating composition of the present embodiment is preferably a water-based coating composition containing water as a solvent.

[0206] The coating composition of the present embodiment may be a solventless coating composition that does not contain a solvent.

[0207] <(D) Ingredient: Other additives> In addition to the above-mentioned components (A), (B), and (C), the coating composition of this embodiment may contain other additives (component (D)) such as a curing accelerator (catalyst), urethane beads, a matting agent, a leveling agent, a thixotropic agent, etc., depending on the intended use. By appropriately adding these other additives (component (D)), coating compositions with different properties, such as a soft-feel coating and a clear coating, can be obtained.

[0208] The curing accelerator (catalyst) is not particularly limited, but examples thereof include commonly used ones such as monoamines, diamines, other triamines, cyclic amines, alcohol amines, ether amines, and metal catalysts.

[0209] The monoamine is not particularly limited, but examples thereof include triethylamine, N,N-dimethylcyclohexylamine, and the like.

[0210] The diamine is not particularly limited, but examples thereof include tetramethylethylenediamine.

[0211] The alcohol amine is not particularly limited, but examples thereof include dimethylethanolamine.

[0212] The metal catalyst is not particularly limited, but examples thereof include potassium acetate, potassium 2-ethylhexanoate, calcium acetate, lead octoate, dibutyltin dilaurate, tin octoate, bismuth neodecanoate, bismuth oxycarbonate, bismuth 2-ethylhexanoate, zinc octoate, zinc neodecanoate, phosphine, and phospholine.

[0213] The matting agent is not particularly limited, but examples thereof include organic fine powders, inorganic fine powders, etc. These matting agents may be used alone or in combination of two or more kinds.

[0214] The organic fine powder is not particularly limited, but examples thereof include a crosslinked acrylic resin polymerized using an unsaturated carboxylic acid alkyl ester monomer and a crosslinking agent, and a crosslinked resin polymerized using an unsaturated nitrile monomer, an aromatic vinyl monomer, and a crosslinking agent.

[0215] The unsaturated carboxylic acid alkyl ester monomer is not particularly limited, but examples thereof include methyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate.

[0216] The unsaturated nitrile monomer is not particularly limited, but examples thereof include acrylonitrile, methacrylonitrile, and ethacrylonitrile.

[0217] The aromatic vinyl monomer is not particularly limited, but examples thereof include styrene and α-methylstyrene.

[0218] These organic fine powders may be used alone or in combination of two or more.

[0219] The inorganic fine powder is not particularly limited, but examples thereof include metal oxide fine powder, silicate compound fine powder, metal carbonate fine powder, nitride fine powder, gypsum fine powder, clay fine powder, talc fine powder, and natural mica fine powder.

[0220] The metal oxide fine powder is not particularly limited, but examples thereof include silicon oxide fine powder, titanium oxide fine powder, aluminum oxide fine powder, and zirconium oxide fine powder.

[0221] The silicate compound fine powder is not particularly limited, but examples thereof include aluminum silicate fine powder and magnesium silicate fine powder.

[0222] The metal carbonate fine powder is not particularly limited, but examples thereof include calcium carbonate fine powder and barium carbonate fine powder.

[0223] The nitride fine powder is not particularly limited, but examples thereof include titanium nitride fine powder and silicon nitride fine powder.

[0224] These inorganic fine powders may be used alone or in combination of two or more kinds.

[0225] Among these, the inorganic fine powder is preferably silicon oxide fine powder, and examples of the silicon oxide fine powder include hydrous or anhydrous silica fine powder.

[0226] Specific examples of such silica fine powders include, but are not limited to, "ACEMATT OK 412 (product name)", "ACEMATT OK 607 (product name)", "ACEMATT OK 900 (product name)", "ACEMATT TS 100 (product name)", "ACEMATT OK 520 (product name)", "ACEMATT 3600 (product name)", and "ACEMATT 3300 (product name)" manufactured by Evonik.

[0227] The leveling agent is not particularly limited, but examples thereof include silicone, aerosil, wax, stearates, and polysiloxanes such as BYK-331 (manufactured by BYK Chemicals).

[0228] As the thixotropic agent, any thixotropic agent that has been used in the thermosetting resin composition of the conventional solder paste can be used. Specific examples of the thixotropic agent include, but are not limited to, castor oil, hydrogenated castor oil, and sorbitol-based thixotropic agents.

[0229] The content of other additives (component (D)) in the coating composition of this embodiment can be adjusted appropriately depending on the type of each additive.

[0230] <Coating film> The coating film of this embodiment is obtained from the coating composition described above. Since the coating film of this embodiment is obtained from the coating composition described above, it has various excellent physical properties.

[0231] <Application> The coating composition of the present embodiment can be suitably used in a wide range of fields, such as coating automobiles, buses, railway vehicles, construction machinery, agricultural machinery, floors, walls and roofs of buildings, metal products, mortar and concrete products, woodworking products, plastic products, and ceramic building materials such as calcium silicate boards and gypsum boards. EXAMPLES

[0232] Hereinafter, the present embodiment will be described in more detail with reference to specific examples and comparative examples, but the present embodiment is not limited by these examples and comparative examples as long as the gist of the present embodiment is not exceeded. In the present examples, "parts" and "%" are based on mass unless otherwise specified.

[0233] Measurements and evaluations of physical properties in the examples and comparative examples described below were carried out by the methods shown below.

[0234] [Hydroxyl value] The hydroxyl value was measured by the following method. First, pyridine was added to 12.5 g of acetic anhydride in a measuring flask to make 50 mL, and an acetylation reagent was prepared. Next, 1.0 to 10.0 g of sample was precisely weighed into a 100 mL eggplant flask. Next, 5 mL of the acetylation reagent and 10 mL of toluene were added to the eggplant flask using a volumetric pipette, and then a cooling tube was attached and the solution in the eggplant flask was stirred and heated at 100°C for 1 hour. Next, 2.5 mL of distilled water was added to the eggplant flask using a volumetric pipette, and the solution in the eggplant flask was heated and stirred for another 10 minutes. After the solution in the eggplant flask was cooled for 2 to 3 minutes, 12.5 mL of ethanol was added to the eggplant flask. Next, 2 to 3 drops of phenolphthalein were added to the eggplant flask as an indicator, and titrated with 0.5 mol / L ethanolic potassium hydroxide. Next, 5 mL of the acetylation reagent, 10 mL of toluene, and 2.5 mL of distilled water were placed in a 100 mL recovery flask, and the solution in the recovery flask was heated and stirred for 10 minutes, and then titration was performed in the same manner (blank test). Based on this result, the hydroxyl value was calculated using the following formula (i). Hydroxyl number (mg-KOH / g) = {(FE) × 28.05 × f} / G (i) In the formula (i), E represents the titer of the sample (mL), F represents the titer of the blank test (mL), G represents the sample mass (g), and f represents the factor of the titrant.

[0235] <Method of manufacturing polyurethane coating film> [Coating process] Each of the coating compositions obtained in the examples and comparative examples described below was applied to a polycarbonate plate ("TAKIRON PC-1600" (product name), 2 mm x 70 mm x 150 mm) so that the dry film thickness was 40 μm. [Drying process] The applied coating composition was baked at 60° C. until the surface no longer showed any traces of finger marks, yielding a polyurethane coating film.

[0236] [Touch evaluation] In the above-mentioned method for producing a polyurethane coating film, after the coating step, the baking time (drying time) until no trace of finger touch remained on the surface was measured.

[0237] [Chemical resistance] After baking until no traces of finger marks were left by the finger touch evaluation, the resulting coating was aged for one day in an atmosphere of 23°C and 50% RH, and a 10 mm diameter cotton ball soaked in various solvents (ethanol (EtOH), methyl ethyl ketone (MEK), xylene, oleic acid) was placed on the aged coating for one minute, and the condition of the coating after removing the solvent remaining on the surface was observed. The evaluation method was as follows. ○: Transparent, no dents △: Slightly cloudy or slightly dented ×: Cloudy or with dents

[0238] [Moisture and heat resistance] After baking until no finger marks were left by the finger touch evaluation, the resulting coating film was aged for one day in an atmosphere of 23°C and 50% RH, and the aged coating film was heated for 10 days under conditions of a temperature of 85°C and a humidity of 85% in a thermohygrostat manufactured by Espec Corporation, product name "PL-1J". After heating, the coating film was cut into 100 squares of 1 mm x 1 mm using a cutter knife according to the cross-cut method of JIS K5600-5-6:1999. Then, cellophane tape was attached to the surface of the coating film where the cuts were made, and the tape was peeled off to measure the number of remaining squares. From the number of squares measured, the adhesion was evaluated based on the following evaluation criteria. (Evaluation Criteria) ◎: The number of squares is 90 or more ○: The number of squares is between 80 and 90 △: The number of squares is between 70 and 80 ×: The number of squares is less than 70, and it is not possible to evaluate it.

[0239] [Weather resistance] After baking until no finger marks were left by the finger touch evaluation, the resulting coating film was aged for one day in an atmosphere of 23°C and 50% RH, and the aged coating film was subjected to a weather resistance test for 250 hours using a DPWL-5R manufactured by Suga Test Instruments Co., Ltd. (black panel temperature 60°C, irradiance 30 w / m2, cycle conditions: irradiation at 60°C for 4 hours, wet at 40°C for 4 hours, ultraviolet fluorescent lamp: SUGA-FS-40). After the test, the coating film was observed with a 6B pencil to see if pencil scratches remained on the coating film in accordance with the pencil hardness method of JIS K5600-5-6:1999. (Evaluation Criteria) ◎: No scratches are visible. ○: There are faint scratches, but the scratches disappear when you run your finger over them. △: There are faint scratches, and the scratches do not disappear even when you run your finger over them. ×: Scratches are clearly visible or coating peeling is observed.

[0240] [Sunscreen resistance] After baking until no traces of finger marks were left by the above-mentioned finger touch evaluation, the resulting coating was aged for one day in an atmosphere of 23°C and 50% RH, and then a sunscreen (Neutrogena Ultra Sheer DRY-TOUCH SUNSCREEN Broad Spectrum SPF 45) was applied to the coating surface at 2g / 4cm. 2 The coating was applied so that the coating would become smooth and then heated at 55°C for 1 hour. The surface of the coating was then thoroughly washed with a small amount of neutral detergent to remove the sunscreen, and the coating was then dried on a horizontal stand in an atmosphere of 23°C and 50% RH. It was then visually evaluated for any abnormalities such as traces of sunscreen remaining, swelling or peeling of the coating. (Evaluation Criteria) ○: No change in the appearance of the coating △: Slight change in coating appearance ×: There is swelling or trace changes in the appearance of the coating film.

[0241] [Scratch resistance] After baking until no finger marks were left by the above finger touch evaluation, the resulting coating film was aged for one day in an atmosphere of 23°C and 50% RH, and the aged coating film was used to attach a brass brush (standard type, 3 lines, manufactured by AS ONE) to a RUBBING TESTER (manufactured by Taihei Rika Kogyo Co., Ltd.) and rub the coating film back and forth 20 times with a load of 745 g to create scratches. The gloss (X1) of the coating film immediately after scratching was measured using a variable angle gloss meter (UGV-6P, manufactured by Suga Test Instruments Co., Ltd.) with a light receiving angle of 60 degrees and an incident angle of 60 degrees. The initial gloss at the same spot before the scratch resistance test was taken as X0, and the gloss retention was calculated using the following formula (ii). Gloss retention (%) = (X1 / X0) × 100 (ii) Next, the scratch resistance was evaluated based on the obtained gloss retention rate according to the following evaluation criteria. Note that coatings with a haze value of 1.0 or more were deemed unevaluable because it was difficult to perform a reproducible evaluation. The haze value can be measured using a haze meter (HMG-2DP, manufactured by Suga Test Instruments Co., Ltd.). (Evaluation Criteria) ◎: Gloss retention is 95% or more ○: Gloss retention is 85% or more but less than 95% △: Gloss retention is 75% or more but less than 85% ×: Gloss retention is less than 75% or evaluation is not possible

[0242] [Polycarbonate diol polymerization example 1] 550g of 2-methyl-1,3-propanediol, 423g of 1,4-butanediol, and 952g of ethylene carbonate were charged into a 3L glass flask (hereinafter also referred to as "reactor") equipped with a rectification column filled with structured packing and a stirrer, and then 0.1925g of titanium tetra-n-butoxide was added as a catalyst. While extracting a part of the distillate, the reaction was carried out at a reaction temperature of 150 to 165°C for 25 hours. Next, the reactor was directly connected to a condenser, and the reaction temperature was raised to 170 to 180°C, and then the pressure was gradually lowered. While appropriately sampling and measuring the hydroxyl value of the polycarbonate diol produced, the diol component in the reactor was distilled off to obtain polycarbonate diol (570g) with a hydroxyl value of 53.1mgKOH / g. To the obtained polycarbonate diol (570 g), 0.178 g of dibutyl phosphate was added and stirred at 115° C. for 3 hours to obtain a polycarbonate diol composition PC-1.

[0243] [Polycarbonate diol polymerization example 2] 234g of 1,4-butanediol, 236g of 1,6-hexanediol, and 396g of ethylene carbonate were charged into a 1L glass flask (hereinafter also referred to as "reactor") equipped with a rectification column filled with structured packing and a stirrer, and then 0.092g of titanium tetra-n-butoxide was added as a catalyst. While extracting a part of the distillate, the reaction was carried out at a reaction temperature of 150 to 165°C for 20 hours. Next, the reactor was directly connected to a condenser, and the reaction temperature was raised to 170 to 180°C, and then the pressure was gradually reduced. While appropriately sampling and measuring the hydroxyl value of the polycarbonate diol produced, the diol component in the reactor was distilled off to obtain a polycarbonate diol (346g) with a hydroxyl value of 56.0mgKOH / g. To the obtained polycarbonate diol (346 g), 0.085 g of dibutyl phosphate was added and stirred at 115° C. for 3 hours to obtain a polycarbonate diol composition PC-2.

[0244] [Polycarbonate diol polymerization example 3] 234g of 1,4-butanediol, 236g of 1,6-hexanediol, and 396g of ethylene carbonate were charged into a 1L glass flask (hereinafter also referred to as "reactor") equipped with a rectification column filled with structured packing and a stirrer, and then 0.086g of titanium tetra-n-butoxide was added as a catalyst. While extracting a part of the distillate, the reaction was carried out at a reaction temperature of 150 to 165°C for 20 hours. Next, the reactor was directly connected to a condenser, and the reaction temperature was raised to 170 to 180°C, and then the pressure was gradually lowered. While appropriately sampling and measuring the hydroxyl value of the polycarbonate diol produced, the diol component in the reactor was distilled off to obtain a polycarbonate diol (350g) with a hydroxyl value of 55.8mgKOH / g. To the obtained polycarbonate diol (360 g), 40 g of polyoxyethylene diol (manufactured by Wako Pure Chemical Industries, Ltd., "Polyethylene glycol 1000" (trade name), number average molecular weight: about 1000, hydroxyl value: about 56.1 mgKOH / g) was added, and the mixture was stirred at 150°C for 6 hours. The reaction temperature was then lowered to 115°C, and 0.080 g of dibutyl phosphate was added, followed by stirring at 115°C for 3 hours to obtain a polycarbonate diol composition PC-3 having a hydroxyl value of 61.1 mgKOH / g.

[0245] [Polycarbonate diol polymerization example 4] 458g of 1,5-pentanediol, 500g of 1,6-hexanediol, and 760g of ethylene carbonate were charged into a 2L glass flask (hereinafter also referred to as "reactor") equipped with a rectification column filled with structured packing and a stirrer, and then 0.086g of titanium tetra-n-butoxide was added as a catalyst. While extracting a part of the distillate, the reaction was carried out at a reaction temperature of 160 to 175°C for 12 hours. Next, the reactor was directly connected to a condenser, and the reaction temperature was raised to 175 to 190°C, and then the pressure was gradually lowered. While appropriately sampling and measuring the hydroxyl value of the polycarbonate diol produced, the diol component in the reactor was distilled off to obtain polycarbonate diol (855g) with a hydroxyl value of 108.8mgKOH / g. To the obtained polycarbonate diol (855 g), 95 g of polyoxyethylene diol (manufactured by Wako Pure Chemical Industries, Ltd., "Polyethylene Glycol 1000" (product name)) was added, and the mixture was stirred at 150°C for 6 hours. The reaction temperature was then lowered to 115°C, and 0.058 g of 85% phosphoric acid was added, followed by stirring at 115°C for 3 hours to obtain a polycarbonate diol composition PC-4 having a hydroxyl value of 110.1 mgKOH / g.

[0246] [Polycarbonate diol polymerization example 5] 330g of 1,4-butanediol, 130g of 1,6-hexanediol, and 415g of ethylene carbonate were charged into a 1L glass flask (hereinafter also referred to as "reactor") equipped with a rectification column filled with structured packing and a stirrer, and then 0.093g of titanium tetra-n-butoxide was added as a catalyst. While extracting a part of the distillate, the reaction was carried out at a reaction temperature of 155 to 165°C for 18 hours. Next, the reactor was directly connected to a condenser, and the reaction temperature was raised to 165 to 180°C, and then the pressure was gradually lowered. While appropriately sampling and measuring the hydroxyl value of the polycarbonate diol produced, the diol component in the reactor was distilled off to obtain a polycarbonate diol (324g) with a hydroxyl value of 109.1mgKOH / g. To the obtained polycarbonate diol (324 g), 36 g of polyoxyethylene diol (manufactured by Wako Pure Chemical Industries, Ltd., "Polyethylene glycol 1000" (product name)) was added, and the mixture was stirred at 150°C for 6 hours. The reaction temperature was then lowered to 115°C, and 0.115 g of dibutyl phosphate was added, followed by stirring at 115°C for 3 hours to obtain polycarbonate diol composition PC-5 having a hydroxyl value of 109.2 mgKOH / g.

[0247] [Polycarbonate diol polymerization example 6] 234g of 1,4-butanediol, 236g of 1,6-hexanediol, and 396g of ethylene carbonate were charged into a 1L glass flask (hereinafter also referred to as "reactor") equipped with a rectification column filled with structured packing and a stirrer, and then 0.090g of titanium tetra-n-butoxide was added as a catalyst. While extracting a part of the distillate, the reaction was carried out at a reaction temperature of 150 to 165°C for 20 hours. Next, the reactor was directly connected to a condenser, and the reaction temperature was raised to 170 to 180°C, and then the pressure was gradually reduced. While appropriately sampling and measuring the hydroxyl value of the polycarbonate diol produced, the diol component in the reactor was distilled off to obtain a polycarbonate diol (350g) with a hydroxyl value of 55.8mgKOH / g. To the obtained polycarbonate diol (210 g), 90 g of Newpol PE-61 (trade name) (manufactured by Sanyo Chemical Industries, Ltd., oxyethylene group / oxy1-methylethylene group=11 / 89 mass%, number average molecular weight: about 2000, hydroxyl value: about 56.1 mgKOH / g) was added, and the mixture was stirred at 150°C for 10 hours. The reaction temperature was then lowered to 115°C, and 0.086 g of dibutyl phosphate was added, followed by stirring at 115°C for 3 hours to obtain a polycarbonate diol composition PC-6 having a hydroxyl value of 55.9 mgKOH / g.

[0248] [Polyisocyanate composition polymerization example 1: PI-1] By synthesizing in accordance with Example 1 of Japanese Patent No. 5183206, an isocyanate composition PI-1 having an isocyanate group mass concentration % (hereinafter also referred to as "NCO %) of 23.1 and an average NCO functional group number of 3.3 was obtained.

[0249] [Polyisocyanate composition polymerization example 1: PI-2] By synthesizing in accordance with Production Example 1 of Japanese Patent No. 6538363, an isocyanate composition PI-2 having an NCO% of 20.1 and an average NCO functionality of 4.3 was obtained.

[0250] [Polyisocyanate composition polymerization example 1: PI-3] By synthesizing in accordance with Example 1 of Japanese Patent No. 6538363, an isocyanate composition PI-3 having an NCO% of 15.6 and an average NCO functionality of 3.9 was obtained.

[0251] <Production of Solvent-Based Clear Coating Composition> [Example 1] Preparation of coating composition 1 Asahi Kasei Corporation's "Duranol T5652 (polycarbonate diol, number average molecular weight about 2000, hydroxyl value 56.1 mgKOH / g, composition: 1,5-pentanediol / 1,6-hexanediol = 50 mol% / 50 mol%)" (trade name) was used as the base agent, and PI-1 was used as the curing agent. The ratio of the number of moles of hydroxyl groups (OH groups) contained in the base agent to the number of moles of isocyanate groups (NCO groups) contained in the curing agent (hereinafter also referred to as "NCO / OH ratio") was 1.5. The base agent and curing agent were weighed into a plastic container, and 0.3% of BYK's "BYK-331" (trade name) was added as a leveling agent and 250 ppm of dibutyltin dilaurate was added as a catalyst relative to the total mass of the base agent and curing agent. Finally, butyl acetate was added as a solvent so that the solid content of the resulting paint composition was 42%, and the mixture was stirred with a stirrer until it was uniform, obtaining paint composition 1. The resulting coating composition was evaluated according to the above-mentioned methods (fingertouch evaluation, chemical resistance, scratch resistance, and moist heat resistance). The evaluation results are shown in Table 1.

[0252] [Example 2] Preparation of coating composition 2 A coating composition 2 was obtained in the same manner as in Example 1, except that PI-2 was used instead of PI-1 as a curing agent. The obtained coating composition was evaluated based on the above-mentioned methods (touch evaluation, chemical resistance, scratch resistance, and moist heat resistance). The evaluation results are shown in Table 1.

[0253] [Examples 3 to 6] Preparation of Coating Compositions 3 to 6 Coating compositions 3 to 6 were obtained using the same method as in Example 2, except that PC-1 to PC-3 and PC-6 were used instead of Duranol T5652 as the main agent. The obtained coating compositions were evaluated according to the above-mentioned methods (touch evaluation, chemical resistance, scratch resistance, and moist heat resistance). The evaluation results are shown in Table 1.

[0254] [ Reference example 7 ] Preparation of coating composition 7 Coating composition 7 was obtained in the same manner as in Example 2, except that "Setalux1152" (trade name) manufactured by Allnex (acrylic polyol, hydroxyl value 138.6 mg KOH / g resin, solid content 61 mass%) was used as the main agent instead of Duranol T5652. The obtained coating composition was evaluated according to the above-mentioned methods (touch evaluation, chemical resistance, scratch resistance, moist heat resistance). The evaluation results are shown in Table 1.

[0255] [Example 8] Preparation of coating composition 8 As the main agent, instead of Duranol T5652, 70% by mass of "Setalux1152" (trade name) manufactured by Allnex and 30% by mass of "Duranol T5651 (polycarbonate diol, number average molecular weight about 1000, hydroxyl value 110.5 mgKOH / g, composition: 1,5-pentanediol / 1,6-hexanediol = 50 mol% / 50 mol%)" (trade name) manufactured by Asahi Kasei Corporation were used, and the same method as in Example 2 was used to obtain coating composition 8. The obtained coating composition was evaluated based on the above-mentioned method (touch evaluation, chemical resistance, scratch resistance, and moist heat resistance). The evaluation results are shown in Table 1.

[0256] [Table 1]

[0257] [Comparative Examples 1 to 6] Preparation of Coating Compositions 9 to 14 Coating compositions 9 to 14 were obtained using the same method as in Examples 1 to 6, except that the amount of catalyst was changed from 250 ppm to 25 ppm. The obtained coating compositions were evaluated based on the above-mentioned methods (touch evaluation, chemical resistance, scratch resistance, and moist heat resistance). The evaluation results are shown in Table 2.

[0258] [Comparative Examples 7-8] Preparation of Coating Compositions 15-16 Except for changing the amount of catalyst from 250 ppm to 0 ppm, Reference Example 7 and ExamplesCoating compositions 15 to 16 were obtained using the same method as in Example 8. The resulting coating compositions were evaluated according to the above-mentioned methods (touch evaluation, chemical resistance, scratch resistance, and moist heat resistance). The evaluation results are shown in Table 2.

[0259] [Table 2]

[0260] <Production of Solvent-Based Soft-Feel Coating Composition> [Example 9] Preparation of coating composition 17 Asahi Kasei Corporation's "Duranol T5652" (trade name) was used as the base agent, and PI-1 was used as the curing agent. The base agent and curing agent were weighed into a plastic container so that the NCO / OH ratio was 1.5. BYK's "BYK-331" (trade name) was added as a leveling agent at 0.3%, Evonik's "ACEMATT TS 100" (trade name) was added as a matting agent at 10.0%, and dibutyltin dilaurate was added as a catalyst at 2000 ppm. Finally, butyl acetate was added as a solvent so that the solid content of the resulting paint composition was 40%, and the mixture was stirred with a stirrer until it was uniform, to obtain paint composition 17. The resulting paint composition was evaluated based on the above methods (touch evaluation, sunscreen resistance, weather resistance). The evaluation results are shown in Table 3.

[0261] [Example 10] Preparation of coating composition 18 A coating composition 18 was obtained using the same method as in Example 9, except that PI-2 was used instead of PI-1 as a curing agent. The obtained coating composition was evaluated based on the above-mentioned methods (touch evaluation, sunscreen resistance, weather resistance). The evaluation results are shown in Table 3.

[0262] [Examples 11 to 14] Preparation of Coating Compositions 19 to 22 Coating compositions 19 to 22 were obtained using the same method as in Example 10, except that PC-1 to PC-3 and PC-6 were used instead of Duranol T5652 as the main agent. The obtained coating compositions were evaluated (touch evaluation, sunscreen resistance, weather resistance) based on the above-mentioned methods. The evaluation results are shown in Table 3.

[0263] [Table 3]

[0264] [Comparative Examples 9 to 14] Preparation of Coating Compositions 23 to 28 Except for changing the amount of catalyst from 2000 ppm to 500 ppm, coating compositions 23 to 28 were obtained using the same method as in Examples 9 to 14. The obtained coating compositions were evaluated (touch evaluation, sunscreen resistance, weather resistance) based on the above-mentioned methods. The evaluation results are shown in Table 4.

[0265] [Table 4]

[0266] <Production of Water-Based Clear Coating Composition> [Example 15] Preparation of coating composition 29 PC-4 was used as the base agent, and "Duranate WT30-100 (polyisocyanate: NCO% 16.4, average NCO functional group number 3.1)" (trade name) manufactured by Asahi Kasei Corporation was used as the curing agent. The base agent and curing agent were weighed into a plastic container so that the NCO / OH ratio was 1.5, and 0.3% of "BYK-331" (trade name) manufactured by BYK was added as a leveling agent relative to the total mass of the base agent and curing agent, and 1000 ppm of "Borchers LH10" (trade name) manufactured by OMG Borchers was added as an aqueous catalyst. Finally, pure water was added as a solvent so that the solid content of the resulting paint composition was 42%, and the mixture was stirred using a stirrer until it was uniformly dispersed to obtain paint composition 29. The resulting paint composition was evaluated based on the above-mentioned methods (touch evaluation, chemical resistance, scratch resistance, and moist heat resistance). The evaluation results are shown in Table 5.

[0267] [Example 16] Preparation of coating composition 30 A coating composition 30 was obtained using the same method as in Example 15, except that PI-3 was used as the curing agent instead of Duranate WT30-100. The obtained coating composition was evaluated based on the above-mentioned methods (touch evaluation, chemical resistance, scratch resistance, and moist heat resistance). The evaluation results are shown in Table 5.

[0268] [Examples 17-18] Preparation of Coating Compositions 31-32 Except for using PC-5 and PC-3 instead of PC-4 as the main agent, coating compositions 31 to 32 were obtained using the same method as in Example 16. The obtained coating compositions were evaluated based on the above-mentioned methods (touch evaluation, chemical resistance, scratch resistance, and moist heat resistance). The evaluation results are shown in Table 5.

[0269] [ Reference example 19 ] Preparation of coating composition 33 A coating composition 33 was obtained in the same manner as in Example 16, except that "Setaqua6515" (trade name) manufactured by Allnex (water-based acrylic polyol, hydroxyl value 108.9 mg KOH / g resin, solid content 45 mass%) was used instead of PC-4 as the base resin. The obtained coating composition was evaluated (touch evaluation, chemical resistance, scratch resistance, and moist heat resistance) based on the above-mentioned methods. The evaluation results are shown in Table 5.

[0270] [Example 20] Preparation of coating composition 34 A coating composition 34 was obtained using the same method as in Example 16, except that the resin ratio of "Setaqua6515" (trade name) manufactured by Allnex was 70% by mass and PC-4 was 30% by mass. The obtained coating composition was evaluated based on the above-mentioned methods (touch evaluation, chemical resistance, scratch resistance, and moist heat resistance). The evaluation results are shown in Table 5.

[0271] [Example 21] Preparation of coating composition 35 Coating composition 35 was obtained in the same manner as in Example 16, except that "DAOTAN TW 6450 / 30WA" (product name) manufactured by Daicel-Allnex Corporation (polyurethane dispersion, hydroxyl value 30 mg KOH / g resin, solid content 30 mass%) was used instead of PC-4 as the main agent. The obtained coating composition was evaluated according to the above-mentioned methods (touch evaluation, chemical resistance, scratch resistance, moist heat resistance). The evaluation results are shown in Table 5.

[0272] [Table 5]

[0273] [Comparative Examples 15-18 and 20] Preparation of Coating Compositions 36-39 and 41 Except for changing the amount of the aqueous catalyst from 1000 ppm to 250 ppm, coating compositions 36 to 39 and 41 were obtained using the same methods as in Examples 15 to 18 and 20. The obtained coating compositions were evaluated according to the above-mentioned methods (touch evaluation, chemical resistance, scratch resistance, and moist heat resistance). The evaluation results are shown in Table 6.

[0274] [Comparative Example 19] Preparation of Coating Composition 40 Except for changing the amount of aqueous catalyst from 1000ppm to 50ppm, Reference example 19 Using the same method as in , a coating composition 40 was obtained. The obtained coating composition was evaluated based on the above-mentioned methods (touch evaluation, chemical resistance, scratch resistance, and moist heat resistance). The evaluation results are shown in Table 6.

[0275] [Table 6]

[0276] <Production of Water-Based Soft-Feel Coating Composition> [Example 22] Preparation of coating composition 42 PC-4 was used as the base agent, and "Duranate WT30-100" (trade name) manufactured by Asahi Kasei Corporation was used as the curing agent. The base agent and curing agent were weighed into a plastic container so that the NCO / OH ratio was 1.5. Based on the total mass of the base agent and curing agent, 0.3% of "BYK-331" (trade name) manufactured by BYK was used as a leveling agent, 10.0% of "ACEMATT TS 100" (trade name) manufactured by Evonik was used as a matting agent, 0.6% of "Disparlon AQ-002" (trade name) manufactured by Kusumoto Chemical Industries, Ltd. was used as a settling prevention agent, and 3250 ppm of "Borchers LH10" (trade name) manufactured by OMG Borchers was used as an aqueous catalyst. Finally, pure water was added as a solvent so that the solid content of the resulting paint composition was 40%, and the paint composition 42 was obtained by stirring using a stirrer until it was uniformly dispersed. The resulting paint composition was evaluated based on the above-mentioned methods (fingertouch evaluation, sunscreen resistance, weather resistance). The evaluation results are shown in Table 7.

[0277] [Example 23] Preparation of coating composition 43 A coating composition 43 was obtained using the same method as in Example 22, except that PI-3 was used as a curing agent instead of Duranate WT30-100. The obtained coating composition was evaluated based on the above-mentioned methods (touch evaluation, sunscreen resistance, weather resistance). The evaluation results are shown in Table 7.

[0278] [Examples 24-25] Preparation of Coating Compositions 44-45 Except for using PC-5 and PC-3 instead of PC-4 as the main agent, coating compositions 44 to 45 were obtained in the same manner as in Example 23. The obtained coating compositions were evaluated according to the above-mentioned methods (touch evaluation, sunscreen resistance, weather resistance). The evaluation results are shown in Table 7.

[0279] [Table 7]

[0280] [Comparative Examples 21 to 24] Preparation of Coating Compositions 46 to 49 Except for changing the amount of catalyst from 3250 ppm to 1000 ppm, coating compositions 46 to 49 were obtained using the same method as in Examples 22 to 25. The obtained coating compositions were evaluated (touch evaluation, sunscreen resistance, weather resistance) based on the above-mentioned methods. The evaluation results are shown in Table 8.

[0281] [Table 8] [Industrial Applicability]

[0282] The coating composition of the present invention can be suitably used in a wide range of fields, such as coating automobiles, buses, railway vehicles, construction machinery, agricultural machinery, floors, walls and roofs of buildings, metal products, mortar and concrete products, woodworking products, plastic products, and ceramic building materials such as calcium silicate boards and gypsum boards.

Claims

1. Component (A): a polyol composition; and component (B): an isocyanate composition are mixed together. The component (A) has a structure represented by the following (AI), The hydroxyl value of the component (A) is 10 to 400 mgKOH / g, The average NCO functionality of the component (B) is 2.0 or more, a mixing step for obtaining a coating composition in which the number of moles of hydroxyl groups (OH groups) contained in the component (A) and the number of moles of isocyanate groups (NCO groups) contained in the component (B) satisfy the relationship of the following formula 1; A coating step of coating the coating composition; A drying step of drying the applied coating composition at 40°C to 200°C to obtain a coating film, In the drying step, the baking time (drying time) required for the surface to no longer be left with a finger mark after coating is 60 minutes or less. 【Chemistry 1】 (In formula (A-I), R 1 is a divalent linear, branched or cyclic aliphatic hydrocarbon group having 2 to 20 carbon atoms, or an aromatic hydrocarbon group. A plurality of R 1 s may be the same or different. a is a number of 1 to 50.) Molar number of NCO groups / Molar number of OH groups=0.2 to 7.0 (Equation 1)

2. The method for producing a polyurethane coating film according to claim 1, wherein the component (A) contains 50% by mass or more and 95% by mass or less of the structure represented by (AI).

3. The method for producing a polyurethane coating film according to claim 1 or 2, wherein the component (A) has a structure represented by the following general formula (I): 【Chemistry 2】 (In general formula (I), R 11 is a divalent linear, branched or cyclic aliphatic hydrocarbon group having from 2 to 20 carbon atoms, or an aromatic hydrocarbon group. 11 may be the same or different. n11 is a number of 7 to 70.)

4. The method for producing a polyurethane coating film according to claim 3 , wherein the component (A) contains 5% by mass or more and 50% by mass or less of the structure represented by general formula (I).

5. The method for producing a polyurethane coating film according to claim 3 or 4, wherein the structure represented by general formula (I) is a polyoxyethylene structure.

6. The method for producing a polyurethane coating film according to claim 3 or 4, wherein the content of oxy 1-methylethylene groups is from 10% by mass to 100% by mass, and the content of oxyethylene groups is from 0% by mass to 90% by mass, relative to the total mass of the structure represented by general formula (I).

7. (A) component: a polyol composition; and (B) component: an isocyanate composition, The component (A) has a structure represented by the following (AI), The hydroxyl value of the component (A) is 10 to 400 mgKOH / g, The average NCO functionality of the component (B) is 2.0 or more, the number of moles of hydroxyl groups (OH groups) contained in the component (A) and the number of moles of isocyanate groups (NCO groups) contained in the component (B) satisfy the relationship of the following formula 1, A coating composition in which the baking time (drying time) until no finger mark is left in the following finger touch evaluation is 60 minutes or less; 【Chemistry 3】 (In formula (A-I), R 1 is a divalent linear, branched or cyclic aliphatic hydrocarbon group having 2 to 20 carbon atoms, or an aromatic hydrocarbon group. A plurality of R 1 s may be the same or different. a is a number of 1 to 50.) Molar number of NCO groups / Molar number of OH groups=0.2 to 7.0 (Equation 1) [Finger touch evaluation] A coating composition is applied to a polycarbonate plate (2 mm x 70 mm x 150 mm) so that the dry film thickness is 40 μm, and the applied coating composition is baked at 60° C. to obtain a polyurethane coating film. The baking time (drying time) until no finger mark remains on the surface after application is measured.

8. The coating composition of claim 7, wherein component (A) contains a carbonate group.

9. The coating composition according to claim 7 or 8, wherein the component (A) contains the following component (A1): Component (A1): A polycarbonate diol composition containing a structure represented by the following general formula (I) and a polycarbonate structure represented by the following formula (A-I), both ends of which are hydroxyl groups and have a hydroxyl value of 10 to 400 mgKOH / g, in which the content of the structure represented by the following general formula (I) is 5% by mass or more and 50% by mass or less, and the content of the polycarbonate structure represented by the following formula (A-I) is 50% by mass or more and 95% by mass or less, based on the total mass of the structure represented by the following general formula (I) and the polycarbonate structure represented by the following formula (A-I). 【Chemistry 4】 (In general formula (I), R 11 is a divalent linear, branched or cyclic aliphatic hydrocarbon group having from 2 to 20 carbon atoms, or an aromatic hydrocarbon group. 11 may be the same or different. n11 is a number of 7 to 70.) 【Chemistry 5】 (In formula (AI), R 1 is a divalent linear, branched or cyclic aliphatic hydrocarbon group having from 2 to 20 carbon atoms, or an aromatic hydrocarbon group. 1 may be the same or different. a is a number from 1 to 50.

10. 10. The coating composition according to claim 9, wherein the structure represented by the general formula (I) is a polyoxyethylene structure.

11. The coating composition according to claim 9, wherein the content of oxy 1-methylethylene groups is 10% by mass or more and 100% by mass or less, and the content of oxyethylene groups is 0% by mass or more and 90% by mass or less, relative to the total mass of the structure represented by the general formula (I).

12. The coating composition according to any one of claims 7 to 11, wherein the coating composition is a solvent-based coating composition.

13. The coating composition according to any one of claims 7 to 11, wherein the coating composition is a water-based coating composition.

14. The coating composition according to any one of claims 7 to 11, wherein the coating composition is a solvent-free coating composition.

15. A coating film obtained from the coating composition according to any one of claims 7 to 14.

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