Polyol composition, polyurethane resin-forming composition, coating agent set, coating film, and method for forming coating film

Abstract

A polyol composition comprising: (A) a polyol comprising at least one selected from the group consisting of polycarbonate polyols and polyester polyols; (B) a urethane-forming metal catalyst; (C) at least one carbonyl compound selected from the group consisting of carboxylic acids, carboxylic acid anhydrides, and beta-diketones; and (D) a hindered amine light stabilizer, wherein the content of volatile organic compounds is 0-10 mass%.

Description

Polyol composition, polyurethane resin-forming composition, coating agent set, coating film, and method for forming a coating film.

[0001] This disclosure relates to a polyol composition, a polyurethane resin-forming composition, a coating agent set, a coating film, and a method for forming a coating film.

[0002] Polyurethane resin-forming compositions containing polyols and polyisocyanates are used as coating agents. Polyurethane resin-forming compositions are generally two-component compositions, prepared by storing a composition containing a polyol as the main component (polyol composition) and a polyisocyanate separately and mixing them at the time of application. Examples of polyols used in coating agents include polycarbonate polyols, polyester polyols, and polyether polyols.

[0003] In recent years, in-mold coating has attracted attention as a method for coating the surface of plastic molded products, etc., from the perspective of reducing environmental impact (see, for example, Patent Document 1). In-mold coating is a method in which a coating agent is injected into a mold, such as a die, while the substrate is placed inside the mold, and the coating agent is reacted to form a coating film on the surface of the substrate. With this method, the mold used to form the substrate can be used as the mold for coating, so it is possible to coat the surface of the substrate in fewer steps compared to conventional coating methods, and it is possible to reduce the amount of waste and energy consumption associated with coating.

[0004] Japanese Patent Publication No. 2005-074896

[0005] Polyol compositions contain a metal catalyst (urethane-forming metal catalyst) as a catalyst for urethane formation to ensure sufficient reactivity with polyisocyanates. However, when a polyol composition contains at least one of polycarbonate polyols and polyester polyols and a urethane-forming metal catalyst, the viscosity of the polyol composition may change significantly due to storage over a certain period. Such viscosity changes affect the miscibility between the polyol composition and polyisocyanates and can lead to a decrease in workability during painting.

[0006] Therefore, one aspect of this disclosure aims to ensure sufficient reactivity of a polyol composition containing at least one of a polycarbonate polyol and a polyester polyol and a urethane-coated metal catalyst with respect to a polyisocyanate, while suppressing changes in the viscosity of the composition over time.

[0007] Some aspects of this disclosure provide the following [1] to [9].

[0008] [1] A polyol composition comprising: (A) a polyol comprising at least one selected from the group consisting of polycarbonate polyols and polyester polyols; (B) a urethane metal catalyst; (C) at least one carbonyl compound selected from the group consisting of carboxylic acids, carboxylic acid anhydrides and β-diketones; and (D) a hindered amine light stabilizer, wherein the content of volatile organic compounds is 0 to 10% by mass.

[0009] [2] (E) The polyol composition according to [1], further containing an ultraviolet absorber.

[0010] [3] The polyol composition according to [1] or [2], wherein the component (C) comprises at least one selected from the group consisting of carboxylic acids and β-diketones.

[0011] [4] The polyol composition according to any one of [1] to [3], wherein the content of component (C) is 0.1 to 30.0 mol per 1 mol of component (B).

[0012] [5] A polyurethane resin-forming composition comprising: (A) a polyol comprising at least one selected from the group consisting of polycarbonate polyols and polyester polyols; (B) a urethane metal catalyst; (C) at least one carbonyl compound selected from the group consisting of carboxylic acids, carboxylic acid anhydrides and β-diketones; (D) a hindered amine light stabilizer; and (F) a polyisocyanate, wherein the content of volatile organic compounds is 0 to 10% by mass.

[0013] [6] The polyurethane resin-forming composition described in [5], used as a coating agent for in-mold coating.

[0014] [7] A coating agent set for preparing a polyurethane resin-forming composition according to [5] or [6], comprising: a first agent containing component (A), component (B), component (C), and component (D); and a second agent containing component (F).

[0015] [8] A coating film comprising a reaction product of the polyurethane resin-forming composition described in [5] or [6].

[0016] [9] A method for forming a coating film, comprising: preparing a substrate and a mold in which the substrate is placed; injecting the polyurethane resin-forming composition described in [5] or [6] into the mold and applying the polyurethane resin-forming composition to the surface of the substrate; and reacting the polyurethane resin-forming composition to form a coating film on the surface of the substrate.

[0017] According to one aspect of this disclosure, it is possible to suppress changes in viscosity of a polyol composition over time while ensuring sufficient reactivity of the polyol composition containing at least one of a polycarbonate polyol and a polyester polyol and a urethane metal catalyst with respect to a polyisocyanate.

[0018] This is a schematic diagram illustrating one embodiment of the in-mold coating method of the present disclosure.

[0019] Several embodiments of this disclosure are described below. However, this disclosure is not limited to the embodiments described below.

[0020] In this specification, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. Unless otherwise specified, the units of the numbers before and after "~" are the same. In numerical ranges described in stages within this specification, the upper or lower limit of one stage may be replaced with the upper or lower limit of another stage. Furthermore, in numerical ranges described within this specification, the upper or lower limit of that range may be replaced with the values ​​shown in the examples. Also, individually stated upper and lower limits can be combined in any way. The materials exemplified below may be used individually or in combination of two or more, unless otherwise specified. The content of each component in a composition, if multiple substances corresponding to each component exist in the composition, means the total amount of those multiple substances present in the composition, unless otherwise specified.

[0021] <Polyol Composition> One embodiment of the present disclosure relates to a polyol composition containing (A) a polyol (hereinafter also referred to as "component (A)") selected from the group consisting of polycarbonate polyols and polyester polyols, (B) a urethane metal catalyst (hereinafter also referred to as "component (B)"), (C) at least one carbonyl compound (hereinafter also referred to as "component (C)") selected from the group consisting of carboxylic acids, carboxylic acid anhydrides and β-diketones, and (D) a hindered amine light stabilizer (hereinafter also referred to as "component (D)"), wherein the content of volatile organic compounds (based on the total mass of the polyol composition) is 0 to 10% by mass. Here, "volatile organic compound" means an organic compound whose boiling point at 1 atm is 180°C or lower.

[0022] The above polyol composition exhibits sufficient reactivity with polyisocyanates while being less susceptible to viscosity changes over time. The reason for this effect is unclear, but it is presumed to be as follows.

[0023] Polycarbonate polyols and polyester polyols contain multiple types of polyols with different molecular weights due to their manufacturing process. However, when a urethane metal catalyst is present in the composition, it is presumed that the urethane metal catalyst promotes the transesterification reaction between these polyols, causing a change in the molecular weight distribution of the polyols over time and resulting in a change in the viscosity of the polyol composition. On the other hand, in the above polyol composition, it is presumed that the specific carbonyl compound added as component (C) coordinates with the urethane metal catalyst, thereby suppressing the catalytic activity of the urethane metal catalyst in the transesterification reaction with the polyols. This suppresses the transesterification reaction between the polyols and thus suppresses the change in viscosity over time.

[0024] Since the above polyol composition has sufficient reactivity with polyisocyanate, a composition containing the above polyol composition and polyisocyanate has polyurethane resin-forming properties. In this specification, a composition containing the above polyol composition and polyisocyanate is referred to as a polyurethane resin-forming composition.

[0025] The above polyol composition tends to maintain its reactivity with polyisocyanate even after storage for a certain period. The reason for this is not clear, but it is presumed that the specific carbonyl compound added as component (C) protects the urethane metal catalyst by coordinating with it, thereby suppressing catalyst deactivation.

[0026] The above polyol composition tends to improve the weather resistance (particularly gloss retention) of a coating film made of polyurethane resin formed using the polyol composition and polyisocyanate. Specifically, coating films formed using the above polyol composition and polyisocyanate tend to show less deterioration of surface gloss due to the influence of the usage environment such as light, temperature, and humidity. Therefore, the above polyol composition can be used to form coating films, and in particular, it can be used to form coating films that can maintain good surface gloss even when used on parts that require weather resistance (for example, plastic molded products used in interior and exterior parts of automobiles).

[0027] Since the content of volatile organic compounds in the above polyol composition (based on the total mass of the polyol composition) is 0 to 10% by mass, it can be used for in-mold coating. By the way, in a general coating agent, volatile organic compounds are used as a solvent to dissolve additives. However, in the in-mold coating method, since the inside of the mold is a closed space, the use of a solvent (volatile organic compound) is restricted in order to avoid poor formation of the coating film due to air bubbles or the like. Therefore, when an additive is used in a coating agent for in-mold coating, energy such as thermal energy is required to dissolve the additive, and there is a problem that the energy consumption during preparation increases. On the other hand, in the above polyol composition, the components (B), (C), and (D) which are additives are easily dissolved in the component (A). Therefore, according to the above polyol composition, there is a tendency to reduce the energy consumption during preparation.

[0028] Hereinafter, the components that can be contained in the polyol composition will be described.

[0029] [Component (A)] The component (A) contains at least one selected from the group consisting of polycarbonate polyol and polyester polyol. As the component (A), one kind of polyol may be used alone, or two or more kinds of polyols may be used in combination.

[0030] From the viewpoint of excellent coating film forming properties in in-mold coating, the component (A) may be liquid at 25°C. In this specification, "liquid at 25°C" means that when it is heated to 80°C or higher, subsequently allowed to stand at 25°C for 24 hours, and then tilted, a slight fluidity can be confirmed by visual observation.

[0031] Polycarbonate polyol is a compound having a plurality of hydroxyl groups (-OH) and a plurality of carbonate groups (-OCOO-). Polycarbonate polyol is, for example, a reaction product of a polyol component (hereinafter, also referred to as "(a1) component") and a carbonate component (hereinafter, also referred to as "(a2) component"), and contains the (a1) component and the (a2) component as monomer units.

[0032] From the viewpoint of obtaining better transparency, the polycarbonate polyol may be an aliphatic polycarbonate polyol. As used herein, the term "aliphatic polycarbonate polyol" means a polycarbonate polyol having no aromatic ring (e.g., benzene ring).

[0033] Component (a1) may contain a glycol. A glycol is a compound having a structure in which a hydroxyl group is substituted on each of two carbon atoms of a linear aliphatic hydrocarbon or a cyclic aliphatic hydrocarbon. Examples of the glycol include linear glycols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, 1,20-eicosanediol, and branched glycols such as 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,3-butanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanediol, 2-methyl-1,8-octanediol, 1,12-octadecanediol. When component (a1) contains some of these glycols alone or a specific combination of several glycols, the polycarbonate polyol is likely to be liquid at 25°C.

[0034] Polycarbonate polyols tend to become liquid at 25°C the lower the crystallinity of component (a1). Furthermore, polycarbonate polyols tend to become liquid at 25°C when two or more components (a1) are used in combination. Also, when two or more components (a1) are used in combination, the smaller the ratio (mass ratio) of the linear single component, the more likely the polycarbonate polyol is to become liquid at 25°C. Additionally, when two or more components (a1) are used in combination, the polycarbonate polyol is even more likely to become liquid at 25°C if it includes a component (a1) with a short carbon chain (for example, a component (a1) with 6 or fewer carbon atoms) and / or a branched component (a1).

[0035] For example, if component (a1) contains at least one selected from the group consisting of 1,3-butanediol, 3-methyl-1,5-pentanediol, and 2-methyl-1,8-octanediol, and a linear glycol having 3 to 6 carbon atoms (i.e., if the polycarbonate polyol contains at least one selected from the group consisting of 1,3-butanediol, 3-methyl-1,5-pentanediol, and 2-methyl-1,8-octanediol, and a linear glycol having 3 to 6 carbon atoms as monomer units), the polycarbonate polyol tends to become liquid at 25°C.

[0036] Component (a1) may contain diols other than glycol. The content of diols other than glycol in component (a1) may be 0 to 45% by mass, 0 to 20% by mass, or 0 to 5% by mass, based on the total mass of component (a1).

[0037] Component (a1) may contain a polyol having three or more hydroxyl groups. The content of the polyol having three or more hydroxyl groups in component (a1) may be 0 to 45% by mass, 0 to 20% by mass, or 0 to 5% by mass, based on the total mass of component (a1).

[0038] Component (a2) can be any compound capable of condensing with component (a1) to produce a polycarbonate polyol. Examples of component (a2) include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, and dipropyl carbonate; alkylene carbonates such as ethylene carbonate and propylene carbonate; and diaryl carbonates such as diphenyl carbonate, dinaphthyl carbonate, diantryl carbonate, diphenanthryl carbonate, diindanyl carbonate, and bistetrahydronaphthyl carbonate. These may be used individually or in combination of two or more.

[0039] The polycarbonate polyol may be a reaction product obtained by reacting the reaction product of component (a1) and component (a2), or component (a1) and component (a2), with another reactant (e.g., polyester polyol) in the presence of a catalyst. When the other reactant is polyester polyol, the polycarbonate polyol can be called polyester polycarbonate polyol. The polyester polycarbonate polyol contains the above components (a1) and (a2) as monomer units and also contains an ester skeleton derived from polyester polyol.

[0040] Polycarbonate polyols may contain silicon atoms. The silicon atom content in the polycarbonate polyol may be 0 to 10% by mass, 0 to 1% by mass, or 0 to 0.1% by mass, based on the total mass of the polycarbonate polyol.

[0041] The hydroxyl value of the polycarbonate polyol may be, for example, 100 to 400 mg KOH / g. Having the hydroxyl value of the polycarbonate polyol within this range improves the low-temperature processability of the polyurethane resin-forming composition, and tends to result in a better appearance of the coating film formed in the in-mold coating method. From the viewpoint of further improving the low-temperature processability of the polyurethane resin-forming composition, enhancing the compatibility between the polyol composition and polyisocyanate, and further improving coating film formation, the hydroxyl value of the polycarbonate polyol may be 150 mg KOH / g or more, or 200 mg KOH / g or more. From the viewpoint of forming a coating film with superior mechanical properties, the hydroxyl value of the polycarbonate polyol may be 380 mg KOH / g or less, or 350 mg KOH / g or less. From these viewpoints, the hydroxyl value of the polycarbonate polyol may be 150 to 380 mg KOH / g or 200 to 350 mg KOH / g.

[0042] In this specification, hydroxyl value refers to the number of milligrams (mg) of potassium hydroxide equivalent to hydroxyl groups in 1 g of sample, and is measured in accordance with JIS K1557-1.

[0043] The molecular weight of the polycarbonate polyol may be, for example, 200 or more. From the viewpoint of obtaining a coating film with superior mechanical properties, the molecular weight of the polycarbonate polyol may be 300 or more, 400 or more, or 450 or more. From the viewpoint of further improving the low-temperature processability of the polyurethane resin-forming composition, improving the compatibility between the polyol composition and polyisocyanate, and further improving coating film formation, the molecular weight of the polycarbonate polyol may be 1100 or less, 1000 or less, or 800 or less. From these viewpoints, the molecular weight of the polycarbonate polyol may be 200 to 1100, 300 to 1000, or 400 to 800.

[0044] In this specification, molecular weight is defined as the molecular weight measured by gel permeation chromatography (for example, the converted molecular weight using a polycarbonate diol consisting of 1,6-hexanediol as a calibration curve), but it can also be calculated from the hydroxyl value and the number of hydroxyl groups (theoretical value).

[0045] The above polycarbonate polyol can be obtained, for example, by reacting component (a1) and component (a2) under a catalyst such as tetrabutoxytitanium. The reaction may be carried out, for example, under a nitrogen atmosphere in a reaction apparatus equipped with a stirrer, thermometer, heating device and distillation column. Specifically, for example, under a nitrogen atmosphere, the temperature can be gradually increased to 190°C while distilling off ethanol, and then the pressure can be gradually reduced to 0.5 kPa or less, and the reaction can be carried out at a pressure of 0.5 kPa or less for 4 hours or more to obtain a polycarbonate polyol as a reaction product of component (a1) and component (a2). The mixing ratio of each component may be adjusted as appropriate, for example, from the viewpoint of hydroxyl value.

[0046] From the viewpoint of obtaining better weather resistance, the content of polycarbonate polyol in component (A) may be 30% by mass or more, 50% by mass or more, or 60% by mass or more, based on the total mass of component (A). From the viewpoint of obtaining better weather resistance, the content of polycarbonate polyol in component (A) may be 90% by mass or less, 85% by mass or less, or 80% by mass or less, based on the total mass of component (A). From the above viewpoint, the content of polycarbonate polyol in component (A) may be 30 to 90% by mass, 50 to 85% by mass or 60 to 80% by mass, based on the total mass of component (A).

[0047] Polyester polyols are compounds having multiple hydroxyl groups (-OH) and multiple ester bonds (-COO-). Examples of polyester polyols include condensed polyester polyols and lactone polyester polyols. Condensed polyester polyols are, for example, condensed polymers of a polyol component (hereinafter also referred to as "component (a3)") and a dicarboxylic acid component (hereinafter also referred to as "component (a4)"), and contain component (a3) ​​and component (a4) as monomer units. Lactone polyester polyols are, for example, ring-opening addition polymers of cyclic ester compounds such as lactones (hereinafter also referred to as "component (a5)"), and contain component (a5) as a monomer unit.

[0048] (a3) Component may include, for example, the same glycols listed in component (a1) above.

[0049] (a4) Examples of components include polybasic acids such as oxalic acid, malonic acid, maleic acid, adipic acid, tartaric acid, pimelic acid, sebacic acid, phthalic acid, and terephthalic acid, or their anhydrides or ester-forming derivatives. These may be used individually or in combination of two or more.

[0050] (a5) Examples of components include β-propiolactone, β-butyrolactone, γ-butyrolactone, β-valerolactone, γ-valerolactone, δ-valerolactone, α-caprolactone, β-caprolactone, γ-caprolactone, δ-caprolactone, ε-caprolactone, α-methyl-ε-caprolactone, β-methyl-ε-caprolactone, 4-methylcaprolactone, γ-caprylolactone, ε-caprylolactone, ε-palmitractone, etc. These may be used individually or in combination of two or more.

[0051] The hydroxyl value of the polyester polyol may be, for example, 100 to 400 mg KOH / g. Having a hydroxyl value within this range enhances the low-temperature processability of the polyurethane resin-forming composition, and tends to result in a better appearance of the coating film formed in the in-mold coating method. From the viewpoint of further enhancing the low-temperature processability of the polyurethane resin-forming composition, improving the compatibility between the polyol composition and polyisocyanate, and further improving coating film formation, the hydroxyl value of the polyester polyol may be 150 mg KOH / g or more, or 200 mg KOH / g or more. From the viewpoint of forming a coating film with superior mechanical properties, the hydroxyl value of the polyester polyol may be 380 mg KOH / g or less, or 350 mg KOH / g or less. From these viewpoints, the hydroxyl value of the polyester polyol may be 150 to 380 mg KOH / g or 200 to 350 mg KOH / g.

[0052] The molecular weight of the polyester polyol may be, for example, 200 or more. From the viewpoint of obtaining a coating film with superior mechanical properties, the molecular weight of the polyester polyol may be 300 or more, 400 or more, or 450 or more. From the viewpoint of further improving the low-temperature processability of the polyurethane resin-forming composition, improving the compatibility between the polyol composition and the polyisocyanate, and further improving the coating film formation properties, the molecular weight of the polyester polyol may be 1100 or less, 1000 or less, or 800 or less. From these viewpoints, the molecular weight of the polyester polyol may be 200 to 1100, 300 to 1000, or 400 to 800.

[0053] From the viewpoint of obtaining better weather resistance, the polyester polyol content in component (A) may be 30% by mass or more, 50% by mass or more, or 60% by mass or more, based on the total mass of component (A). From the viewpoint of obtaining better weather resistance, the polyester polyol content in component (A) may be 90% by mass or less, 85% by mass or less, or 80% by mass or less, based on the total mass of component (A). From the above viewpoint, the polyester polyol content in component (A) may be 30 to 90% by mass, 50 to 85% by mass or 60 to 80% by mass, based on the total mass of component (A).

[0054] Component (A) may consist only of a polyol selected from the group consisting of polycarbonate polyols and polyester polyols (hereinafter referred to as "polyol (A1)"), but may also contain other polyols (hereinafter referred to as "polyol (A2)").

[0055] From the viewpoint of obtaining better weather resistance, the content of polyol (A1) in component (A) may be 30% by mass or more, 50% by mass or more, or 60% by mass or more, based on the total mass of component (A). From the viewpoint of obtaining better weather resistance, the content of polyol (A1) in component (A) may be 90% by mass or less, 85% by mass or less, or 80% by mass or less, based on the total mass of component (A). From the above viewpoint, the content of polyol (A1) in component (A) may be 30 to 90% by mass, 50 to 85% by mass or 60 to 80% by mass, based on the total mass of component (A).

[0056] As polyol (A2), a polyol with a molecular weight of less than 200 (hereinafter referred to as "low molecular weight polyol") may be used. The molecular weight of the low molecular weight polyol may be, for example, 50 or more and less than 200, and may be 60 to 180 or 70 to 150.

[0057] The low molecular weight polyol may be a diol or a polyol having three or more hydroxyl groups. When the low molecular weight polyol contains a diol, it is easier to obtain a coating film with superior self-healing properties, and it also improves the compatibility between the polyol composition and the polyisocyanate, as well as enhances coating film formation due to lower viscosity.

[0058] Examples of diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2-methyl-1,3-propanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, dimethylolheptane, diethylene glycol, dipropylene glycol, neopentyl glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, and dimerdiol. From the viewpoint of obtaining a coating film with superior self-healing properties, improving the compatibility between the polyol composition and the polyisocyanate, and further enhancing coating film formation by lowering viscosity, at least one selected from the group consisting of 1,3-butanediol and 2-methyl-1,3-propanediol may be used. The above-mentioned diols can be used alone or in combination of two or more types.

[0059] The content of the above-mentioned diol may be 5 to 55% by mass, 10 to 50% by mass, or 15 to 40% by mass, based on the total mass of component (A), from the viewpoint of obtaining a coating film with better self-healing properties, improving compatibility between the polyol composition and polyisocyanate, and further enhancing coating film formation by lowering viscosity.

[0060] The content of low molecular weight polyols may be 10 to 70% by mass, 15 to 50% by mass, or 20 to 40% by mass, based on the total mass of component (A), from the viewpoint of suppressing a decrease in self-healing properties and curability.

[0061] The average hydroxyl value of component (A) may be 300 mg KOH / g or more, or 400 mg KOH / g or more, or 500 mg KOH / g or more, from the viewpoint of having superior weather resistance (especially gloss retention). The average hydroxyl value of component (A) may be 800 mg KOH / g or less, or 700 mg KOH / g or less, or 600 mg KOH / g or less, from the viewpoint of further improving the low-temperature processability of the polyurethane resin-forming composition, improving the compatibility between the polyol composition and the polyisocyanate, and further improving the film-forming properties. From these viewpoints, the average hydroxyl value of component (A) may be 300 to 800 mg KOH / g, or 400 to 700 mg KOH / g or 500 to 600 mg KOH / g. The average hydroxyl value of component (A) is the weighted average of the hydroxyl values ​​weighted by the mass of each polyol contained in component (A). It is calculated by multiplying the hydroxyl value of each polyol by its respective mass, summing the values, and then dividing by the mass of component (A) (the total mass of each polyol).

[0062] The average number of hydroxyl groups in component (A) may be 2.0 to 3.0, or 2.0 to 2.5 or 2.0 to 2.3, from the viewpoint of obtaining better weather resistance. The average number of hydroxyl groups in component (A) is the weighted average value of the number of hydroxyl groups weighted by the amount of substance of each polyol contained in component (A), and is obtained by multiplying the number of hydroxyl groups of each polyol by their respective amounts of substance, finding the sum, and dividing by the amount of substance of component (A) (the sum of the amounts of substance of each polyol).

[0063] The content of component (A) may be, for example, 50 to 99% by mass, 60 to 98% by mass, or 70 to 97% by mass, based on the total mass of the polyol composition.

[0064] [Component (B)] Component (B) (urethane metal catalyst) is a metal catalyst that promotes urethane formation through the reaction of polyol and polyisocyanate. Examples of component (B) include tin compounds, iron compounds, lithium compounds, lead compounds, zinc compounds, etc. These may be used individually or in combination of two or more. Component (B) may contain a tin compound from the viewpoint of promoting the reaction between polyol and polyisocyanate and obtaining a good coating film appearance.

[0065] Examples of tin compounds include dioctyl tin dilaurate, dibutyl tin dilaurate, dibutyl tin dioctoate, tin 2-ethylhexanoate, dibutyl tin oxylaurate, dibutyl tin diacetate, dibutyl tin bis(acetylacetonate), and dibutyl tin diversate. These can be used individually or in combination of two or more. Dibutyl tin dilaurate may be used as the tin compound from the viewpoint of promoting the reaction between the polyol and the polyisocyanate, and from the viewpoint of obtaining a good coating film appearance.

[0066] Examples of iron compounds include iron acetylacetonate and iron chloride. These can be used individually or in combination of two or more.

[0067] Examples of lithium compounds include lithium acetylacetonate and lithium octylate. These can be used individually or in combination of two or more.

[0068] Examples of lead compounds include lead octoate. These can be used individually or in combination of two or more.

[0069] Examples of zinc compounds include zinc octoate. These can be used individually or in combination of two or more.

[0070] From the viewpoint of promoting the reaction between the polyol and the polyisocyanate, the content of component (B) may be 0.1 parts by mass or more, 0.3 parts by mass or more, or 0.5 parts by mass or more per 100 parts by mass of component (A). From the viewpoint of reducing the rate of change in viscosity over time and obtaining better weather resistance and hydrolysis resistance, the content may be 3.5 parts by mass or less, 1.5 parts by mass or less, or 1.0 part by mass or less per 100 parts by mass of component (A). From these viewpoints, the content of component (B) may be 0.1 to 3.5 parts by mass, 0.3 to 1.5 parts by mass, or 0.5 to 1.0 parts by mass per 100 parts by mass of component (A).

[0071] [Component (C)] Component (C) comprises at least one carbonyl compound selected from the group consisting of carboxylic acids, carboxylic acid anhydrides, and β-diketones. These carbonyl compounds may have coordinating properties with component (B). For example, component (C) may be a carbonyl compound that can form a coordination bond with the metal constituting component (B). Component (C) may be one carbonyl compound used alone, or two or more carbonyl compounds may be used in combination.

[0072] A carboxylic acid has at least one carboxyl group (-COOH). The number of carboxyl groups in a carboxylic acid may be one or more. From the viewpoint of excellent solubility in polyols and promoting the reaction between polyols and isocyanates, the number may be 1 to 3, and from the viewpoint of further promoting the reaction between polyols and isocyanates, it may be 1. From the viewpoint of reducing the rate of change in viscosity over time, the carboxylic acid may be a compound represented by the following formula (C-1).

[0073] In formula (C-1), R １ｃThis represents an alkyl group having 1 to 17 carbon atoms. The alkyl group may be linear or branched. The number of carbon atoms in the alkyl group may be 3 to 15 or 5 to 11. Examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, 1-ethylpentyl group, 1-butylheptyl group, and the like.

[0074] Specific examples of carboxylic acids include acetic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, 2-ethylhexanoic acid, 2-butyloctanoic acid, isobutanoic acid, isopentanoic acid, and citric acid. These can be used individually or in combination of two or more. From the viewpoint of excellent solubility in polyols, carboxylic acids having 2 to 12 carbon atoms and branched carboxylic acids such as 2-ethylhexanoic acid may be used, and in particular, carboxylic acids that are liquid at 40°C may be used. From the viewpoint of further reducing the rate of change in viscosity over time, at least one selected from the group consisting of 2-ethylhexanoic acid, isobutanoic acid, isopentanoic acid, and 2-butyloctanoic acid may be used. From the viewpoint of obtaining a coating film with a better appearance and a coating film with better mechanical properties, at least one selected from the group consisting of acetic acid and 2-ethylhexanoic acid may be used.

[0075] A carboxylic acid anhydride has at least one acid anhydride group (-COOCO-). The number of acid anhydride groups in a carboxylic acid anhydride may be one or more. From the viewpoint of reducing the rate of change in viscosity over time, the carboxylic acid anhydride may be a compound represented by the following formula (C-2).

[0076] In formula (C-2), R ２ｃ and R ３ｃEach independently represents an alkyl group having 1 to 5 carbon atoms. R ２ｃ and R ３ｃ Examples of the alkyl group represented by are the same as the examples of the alkyl group having 1 to 5 carbon atoms among the alkyl groups represented by R １ｃ R and R ２ｃ and R ３ｃ may be the same as or different from each other.

[0077] Specific examples of the carboxylic acid anhydride include acetic anhydride, propanoic anhydride, butanoic anhydride, and the like. These can be used alone or in combination of two or more. From the viewpoint of further reducing the rate of change of viscosity over time, acetic anhydride may be used.

[0078] β-diketone is a compound having a structure in which two ketones are bonded via a methylene group (—COCH ２ CO—). From the viewpoint of further reducing the rate of change of viscosity over time, the β-diketone may be a compound represented by the following formula (C-3).

[0079] In formula (C-3), R ４ｃ and R ５ｃ each independently represents an alkyl group having 1 to 5 carbon atoms. R ４ｃ and R ５ｃ Examples of the alkyl group represented by are the same as the examples of the alkyl group having 1 to 5 carbon atoms among the alkyl groups represented by R １ｃ R and R ４ｃ and R ５ｃ may be the same as or different from each other.

[0080] Specific examples of the β-diketone include acetylacetone and the like. These can be used alone or in combination of two or more. From the viewpoint of further reducing the rate of change of viscosity over time, acetylacetone may be used.

[0081] Component (C) may contain at least one selected from the group consisting of carboxylic acids and β-diketones, from the viewpoint of reducing the rate of change in viscosity over time, and may contain at least one selected from the group consisting of compounds represented by formula (C-1) and compounds represented by formula (C-3), and may contain at least one selected from the group consisting of 2-ethylhexanoic acid, isobutanoic acid, isopentanoic acid and acetylacetone.

[0082] The molecular weight of component (C) may be, for example, 60 to 400, 80 to 300, or 100 to 200. If component (C) contains multiple compounds, the number average molecular weight of the multiple compounds may be within the above range.

[0083] From the viewpoint of reducing the rate of change in viscosity over time, the content of component (C) may be 0.1 parts by mass or more, 0.3 parts by mass or more, 0.5 parts by mass or more, or 0.8 parts by mass or more per 100 parts by mass of component (A). From the viewpoint of making it easier to obtain a coating film with superior mechanical properties, the content of component (C) may be 1.5 parts by mass or less, 1.0 part by mass or less, or 0.6 parts by mass or less per 100 parts by mass of component (A). From these viewpoints, the content of component (C) may be 0.1 to 1.5 parts by mass, 0.3 to 1.0 parts by mass, 0.5 to 1.5 parts by mass, 0.8 to 1.5 parts by mass, or 0.1 to 0.6 parts by mass per 100 parts by mass of component (A).

[0084] From the viewpoint of reducing the rate of change in viscosity over time, the content of component (C) may be 1.0 mmol or more, 1.5 mmol or more, 2.0 mmol or more, 2.5 mmol or more, or 3.0 mmol or more per 100 g of component (A). From the viewpoint of obtaining a coating film with superior mechanical properties and promoting the reaction between the polyol and the isocyanate, the content of component (C) may be 20.0 mmol or less, 16.0 mmol or less, 12.0 mmol or less, 10.0 mmol or less, or 8.0 mmol or less per 100 g of component (A). From these viewpoints, the content of component (C) may be 1.0 to 20.0 mmol, 1.0 to 16.0 mmol, 1.0 to 12.0 mmol, 1.5 to 12.0 mmol, 2.0 to 10.0 mmol, 2.5 to 10.0 mmol, or 3.0 to 8.0 mmol per 100 g of component (A).

[0085] The content of component (C) may be 0.1 mol or more, 1.0 mol or more, 1.5 mol or more, 2.0 mol or more, 2.5 mol or more, 3.0 mol or more, or 3.5 mol or more per 1.0 mol of component (B), from the viewpoint of reducing the rate of change in viscosity over time. The content of component (C) may be 30.0 mol or less, 20.0 mol or less, 15.0 mol or less, 12.0 mol or less, 11.0 mol or less, 10.0 mol or less, or 8.0 mol or less per 1.0 mol of component (B), from the viewpoint of making it easier to obtain a coating film with superior mechanical properties and from the viewpoint of promoting the reaction between the polyol and the isocyanate. From these perspectives, the content of component (C) may be 0.1 to 30.0 mol, 1.0 to 20.0 mol, 1.5 to 15.0 mol, 2.0 to 12.0 mol, 2.5 to 11.0 mol, 3.0 to 10.0 mol, or 3.5 to 8.0 mol per 1.0 mol of component (B).

[0086] [Component (D)] Component (D) (hindered amine-based light stabilizer) is an additive that enhances the light stability of the resin by capturing radicals, which are factors that degrade the resin. Component (D) has a hindered amine structure represented by the following formula (D-1), for example.

[0087] In formula (D-1), X represents a substituent such as a hydrogen atom or hydrocarbon group, and * represents a bond.

[0088] As component (D), a wide range of known hindered amine-based light stabilizers used in the field of resin materials can be used. From the viewpoint of obtaining better solubility in component (A) and better weather resistance, a compound in which X in formula (D-1) is a methyl group (i.e., a compound having the structure represented by the following formula (D-2)) may be used.

[0089] The molecular weight of component (D) may be, for example, 400 to 4000. From the viewpoint of superior solubility in component (A), the molecular weight of component (D) may be less than 1000, 700 or less, or 500 or less, and may be 400 or more but less than 1000, 400 to 700, or 400 to 500. Here, if component (D) contains multiple compounds, the weight-average molecular weight of the multiple compounds may be within the above range.

[0090] The base constant (pKb) of component (D) may be, for example, 4 to 12, and may be 4 to 9 from the viewpoint of superior solubility in component (A).

[0091] (D) Specific examples of component include a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and methyl(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate (Tinuvin 292 from BASF), and a reaction product of 1,2,3,4-butanetetracarboxylic acid tetramethyl ester, 1,2,2,6,6-pentamethyl-4-piperidinol, and β,β,β',β'-tetramethyl-2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diethanol (ADEKA stab from ADEKA Corporation). Examples include LA-63P), bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (Tinuvin 770 from BASF), 2,2,6,6-tetramethyl-1-[2-[(3,5,5-trimethyl-1-oxohexyl)oxy]ethyl]-4-piperidinyl 3,5,5-trimethylhexanoate (Tinuvin 249 from BASF), etc.

[0092] From the viewpoint of superior weather resistance (especially gloss retention), the content of component (D) may be 0.05 parts by mass or more, 0.1 parts by mass or more, or 0.2 parts by mass or more, per 100 parts by mass of component (A). From the viewpoint of superior mechanical properties, the content of component (D) may be 5 parts by mass or less, 3 parts by mass or less, or 2 parts by mass or less, per 100 parts by mass of component (A). From the above viewpoint, the content of component (D) may be 0.05 to 5 parts by mass, 0.1 to 3 parts by mass or 0.2 to 2 parts by mass, per 100 parts by mass of component (A).

[0093] [Component (E)] The polyol composition may further contain (E) an ultraviolet absorber (hereinafter also referred to as "component (E)"). An ultraviolet absorber is an additive that has the function of absorbing ultraviolet light. Examples of component (E) include triazine-based ultraviolet absorbers and oxalic acid anilide-based ultraviolet absorbers. These may be used individually or in combination of two or more. From the viewpoint of superior solubility with component (A), component (E) may contain a triazine-based ultraviolet absorber.

[0094] As the triazine-based ultraviolet absorber, a wide range of known triazine-based ultraviolet absorbers used in the field of resin materials can be used. From the viewpoint of obtaining better solubility in component (A) and better weather resistance, a compound represented by the following formula (E-1) may be used.

[0095] In formula (E-1), R １ R represents a hydrocarbon group having 1 to 15 carbon atoms. ２ ~R ５ Each of these independently represents a hydrogen atom, a hydroxyl group, a methyl group, or an ethyl group. １ The hydrogen atoms in the hydrocarbon group represented by may be substituted with hydroxyl groups, or with alkoxy groups having 1 to 15 carbon atoms. ２ ~R ５ This may be a hydrogen atom, a methyl group, or an ethyl group, and may be a methyl group or an ethyl group, or it may be a methyl group. The effect of improving solubility and weather resistance tends to increase in the order of hydrogen atom, ethyl group, and methyl group.

[0096] R １ The hydrocarbon group represented by may be, for example, an alkyl group. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tetradecyl, and pentadecyl groups. The hydrogen atoms of these alkyl groups may be substituted with hydroxyl groups, or with alkoxy groups having 1 to 15 carbon atoms. Examples of alkoxy groups having 1 to 15 carbon atoms include methoxy, ethoxy, propyloxy, isopropyloxy, butyloxy, isobutyloxy, t-butyloxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tetradecyloxy, and pentadecyloxy groups.

[0097] Triazine-based ultraviolet absorbers may contain a compound represented by the following formula (E-2) in order to improve solubility in component (A) and reduce precipitation at low temperatures (improve low-temperature stability).

[0098] In formula (E-2), R １１ R represents an alkyl group having 1 to 15 carbon atoms. ２ ~R ５ R in equation (E-1) ２ ~R ５ This is synonymous with R. １１ Examples of alkyl groups represented by R include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, undecyl group, dodecyl group, tetradecyl group, pentadecyl group, etc. １１ The alkyl group represented by may be a methyl group, from the viewpoint of further improving solubility in component (A) and low-temperature stability.

[0099] Specific examples of triazine-based UV absorbers include 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine (Tinuvin 405 from BASF), 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl)-5-(octyloxy)phenol, and 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6- Examples include a mixture of bis(2,4-dimethylphenyl)-1,3,5-triazine and 2-[4-[(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine (Tinuvin 400, manufactured by BASF), and 6-methylheptyl 2-[4-[4,6-bis(biphenyl-4-yl)-1,3,5-triazine-2-yl]-3-hydroxyphenoxy]propanoate (Tinuvin 479, manufactured by BASF).

[0100] From the viewpoint of superior weather resistance (especially resistance to yellowing), the content of component (E) may be 0.05 parts by mass or more per 100 parts by mass of component (A), and from the viewpoint of superior mechanical properties, it may be 5 parts by mass or less per 100 parts by mass of component (A). From these viewpoints, the content of component (E) may be 0.05 to 5 parts by mass per 100 parts by mass of component (A). From the same viewpoint as above, the content of component (E) may be 0.1 parts by mass or more or 0.2 parts by mass or more, 3 parts by mass or less or 2 parts by mass or less, 0.1 to 3 parts by mass or 0.2 to 2 parts by mass per 100 parts by mass of component (A).

[0101] From the viewpoint of superior weather resistance, the total content of component (D) and component (E) may be 0.5 parts by mass or more, 0.6 parts by mass or more, or 0.7 parts by mass or more, per 100 parts by mass of component (A). From the viewpoint of superior mechanical properties, the total content of component (D) and component (E) may be 8 parts by mass or less, 5 parts by mass or less, or 3 parts by mass or less, per 100 parts by mass of component (A). From the above viewpoint, the total content of component (D) and component (E) may be 0.5 to 8 parts by mass, 0.6 to 5 parts by mass or 0.7 to 3 parts by mass, per 100 parts by mass of component (A).

[0102] [Volatile Organic Compounds] Examples of volatile organic compounds include ketone compounds such as methyl ethyl ketone, acetylacetone, methyl isobutyl ketone, and cyclohexanone; aromatic compounds such as toluene and xylene; glycol ether compounds such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, and propylene glycol monomethyl ether acetate; ester compounds such as ethyl acetate, butyl acetate, methyl cellosolve acetate, and cellosolve acetate; and Solvesso #100 and Solvesso #150 (both trade names, manufactured by ExxonMobil). Note that volatile organic compounds can also be components (A) to (E). That is, even if a compound falls under components (A) to (E), if its boiling point at 1 atm is 180°C or lower, it is a volatile organic compound.

[0103] The content of volatile organic compounds is 0 to 10% by mass, based on the total mass of the polyol composition. Good in-mold coating properties can be obtained by having the content of volatile organic compounds within the above range. The content of volatile organic compounds may be 5% by mass or less, 1% by mass or less, or 0.1% by mass or less, based on the total mass of the polyol composition. When a volatile organic compound is used as component (C), the content of the volatile organic compound may be 0.1 parts by mass or more, 0.3 parts by mass or more, 0.5 parts by mass or more, or 0.8 parts by mass or more, 1.5 parts by mass or less, 1.0 parts by mass or less, or 0.6 parts by mass or less, 0.1 to 1.5 parts by mass, 0.3 to 1.0 parts by mass, 0.5 to 1.5 parts by mass, 0.8 to 1.5 parts by mass, or 0.1 to 0.6 parts by mass, based on 100 parts by mass of component (A).

[0104] [Other Components] The polyol composition may further contain other components besides those described above. Examples of other components include antioxidants such as 2,6-di-tert-butyl-4-methylphenol, pigments, dyes, flame retardants, hydrolysis inhibitors, lubricants, plasticizers, fillers, antistatic agents, dispersants, storage stabilizers, thickeners, internal release agents, surface modifiers, defoamers, and antibacterial agents.

[0105] The polyol composition may further contain hydroxyl group-containing compounds other than component (A) as other components. However, from the viewpoint of obtaining better transparency, the polyol composition does not need to contain hydroxyl group-containing compounds having aromatic rings. The content of hydroxyl group-containing compounds having aromatic rings may be 5% by mass or less, or 0% by mass, based on the total mass of the polyol composition.

[0106] The viscosity of the polyol composition at 25°C may be 10 to 10,000 mPa·s, 50 to 8,000 mPa·s, 100 to 5,000 mPa·s, or 200 to 2,000 mPa·s. When the viscosity of the polyol composition at 25°C is within the above range, a polyurethane resin-forming composition with superior film-forming properties is more likely to be obtained. In this specification, the viscosity at 25°C is a value measured using a B-type viscometer.

[0107] <Polyurethane Resin Forming Composition> Another embodiment of the present disclosure relates to a polyurethane resin forming composition containing the above-described components (A) to (D) and (F) polyisocyanate (hereinafter also referred to as "component (F)"), wherein the content of volatile organic compounds (based on the total mass of the polyurethane resin forming composition) is 0 to 10% by mass.

[0108] The above polyurethane resin-forming composition facilitates the formation of a coating film with excellent weather resistance during in-mold painting. Therefore, the above polyurethane resin-forming composition can be used as a coating agent for in-mold painting (in-mold coating agent), and in particular, it can be used as a coating agent for plastic molded products used in the interior and exterior parts of automobiles.

[0109] Furthermore, the coating film formed by the above polyurethane resin-forming composition tends to have excellent self-healing properties. While self-healing properties of the coating film are not always necessary, they may be beneficial in applications of plastic molded products used in automotive interior and exterior parts.

[0110] The details of components (A) to (D) contained in the polyurethane resin-forming composition are the same as the details of components (A) to (D) contained in the polyol composition of the above embodiment. The polyurethane resin-forming composition may further contain components other than components (A) to (D) that may be contained in the polyol composition of the above embodiment (component (E), other components).

[0111] The polyurethane resin-forming composition may contain the polyol composition of the above embodiment. That is, the polyurethane resin-forming composition may be a mixture of the polyol composition of the above embodiment, component (F), and other components that are optionally included. In this case, the content of the polyol composition may be, for example, 10 to 80% by mass, 20 to 70% by mass, or 30 to 60% by mass, based on the total mass of the polyurethane resin-forming composition.

[0112] The content of volatile organic compounds in the polyurethane resin-forming composition (based on the total mass of the polyurethane resin-forming composition) is 0 to 10% by mass. Good in-mold coating properties can be obtained by having the content of volatile organic compounds within the above range. The content of volatile organic compounds may be 5% by mass or less, 1% by mass or less, or 0.1% by mass or less, based on the total mass of the polyurethane resin-forming composition. When a volatile organic compound is used as component (C), the content of the volatile organic compound may be 0.1 parts by mass or more, 0.3 parts by mass or more, 0.5 parts by mass or more, or 0.8 parts by mass or more, 1.5 parts by mass or less, 1.0 parts by mass or less, or 0.6 parts by mass or less, 0.1 to 1.5 parts by mass, 0.3 to 1.0 parts by mass, 0.5 to 1.5 parts by mass, 0.8 to 1.5 parts by mass, or 0.1 to 0.6 parts by mass, per 100 parts by mass of component (A).

[0113] [Component (F): Polyisocyanate] Polyisocyanate is a compound having multiple isocyanate groups (-NCO). Component (F) may be a single polyisocyanate or a combination of two or more polyisocyanates.

[0114] Component (F) may be liquid at 25°C from the viewpoint of having superior film-forming properties in in-mold coating.

[0115] Component (F) may include a non-aromatic polyisocyanate in order to further improve the weather resistance (especially resistance to yellowing) of the coating film. In this specification, "non-aromatic polyisocyanate" means a polyisocyanate that does not have an aromatic ring (e.g., a benzene ring).

[0116] Examples of non-aromatic polyisocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates, and modified versions thereof. Modified versions may be included from the viewpoint of improving miscibility with polyols, curing of the polyurethane resin-forming composition with shorter heating times, obtaining coating films with superior mechanical properties, and obtaining superior weather resistance and hydrolysis resistance. Examples of modified versions include isocyanurate modified versions, allophanate modified versions, biuret modified versions, urethane modified versions, urea modified versions, carbodiimide modified versions, uretonimine modified versions, uretdione modified versions, iminooxadiazine modified versions, and the like.

[0117] Examples of aliphatic polyisocyanates include hexamethylene diisocyanate, tetramethylene diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methylpentane-1,5-diisocyanate, lysine diisocyanate, trioxyethylene diisocyanate, ethylene diisocyanate, trimethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, 2,2'-dimethylpentane diisocyanate, 2,2,4-trimethylhexane diisocyanate, decamethylene diisocyanate, butene diisocyanate, 1,3-butadiene-1,4-diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate. Examples include ethylene diisocyanate, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, 1,8-diisocyanate-4-isocyanate methyl octane, 2,5,7-trimethyl-1,8-diisocyanate-5-isocyanate methyl octane, bis(isocyanate ethyl) carbonate, bis(isocyanate ethyl) ether, 1,4-butylene glycol dipropyl ether-α,α'-diisocyanate, lysine diisocyanate methyl ester, 2-isocyanate ethyl-2,6-diisocyanate hexanoate, and 2-isocyanate propyl-2,6-diisocyanate hexanoate. These may be used individually or in combination of two or more.

[0118] Examples of alicyclic polyisocyanates include isophorone diisocyanate, cyclohexyl diisocyanate, bis(isocyanate-methyl)cyclohexane, dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, dicyclohexyldimethylmethane diisocyanate, 2,2'-dimethyldicyclohexylmethane diisocyanate, bis(4-isocyanate-n-butylidene)pentaerythritol, and hydrogenated dimer acid diisocyanate. , 2-isocyanatemethyl-3-(3-isocyanatetopropyl)-5-isocyanatemethyl-bicyclo[2.2.1]-heptane, 2-isocyanatemethyl-3-(3-isocyanatetopropyl)-6-isocyanatemethyl-bicyclo[2.2.1]-heptane, 2-isocyanatemethyl-2-(3-isocyanatetopropyl)-5-isocyanatemethyl-bicyclo[2.2.1]-heptane, 2-isocyanatemethyl-2-(3-isocyanatepropyl (L)-6-isocyanatemethyl-bicyclo[2.2.1]-heptane,2-isocyanatemethyl-3-(3-isocyanatetopropyl)-5-(2-isocyanateethyl)-bicyclo-[2.2.1]-heptane,2-isocyanatemethyl-3-(3-isocyanatetopropyl)-6-(2-isocyanateethyl)-bicyclo-[2.2.1]-heptane,2-isocyanatemethyl-2-(3-isocyanatetopropyl)-5-(2-isocyanateethyl) Examples include bicyclo-[2.2.1]-heptane, 2-isocyanatemethyl-2-(3-isocyanatepropyl)-6-(2-isocyanateethyl)-bicyclo-[2.2.1]-heptane, 2,5-bis(isocyanatemethyl)-bicyclo[2.2.1]-heptane, hydrogenated diphenylmethane diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, and hydrogenated tetramethylxylene diisocyanate. These may be used individually or in combination of two or more.

[0119] Among the polyisocyanates described above, when component (F) contains an isocyanurate modified aliphatic diisocyanate, the curability (e.g., low-temperature rapid curing) tends to be further improved. From the viewpoint of further improving curability, the content of the above isocyanurate modified aliphatic diisocyanate in component (F) may be 10% by mass or more, 30% by mass or more, or 50% by mass or more, or 100% by mass or less, 90% by mass or less, or 70% by mass or less, or 10 to 100% by mass, 30 to 90% by mass, or 50 to 70% by mass. Note that the above content is based on the total mass of component (F).

[0120] If component (F) contains an isocyanurate modified aliphatic diisocyanate, component (F) may also contain modified non-aromatic polyisocyanates other than the isocyanurate modified aliphatic diisocyanate, to the extent that it does not impair the purpose of this disclosure. The content of modified non-aromatic polyisocyanates other than the isocyanurate modified aliphatic diisocyanate in component (F) may be 90% by mass or less, 70% by mass or less, 50% by mass or less, 30% by mass or less, or 10% by mass or less, and may also be 0% by mass. The above content is based on the total mass of component (F).

[0121] The NCO content of component (F) may be 10 to 40% by mass, and may also be 15 to 35% by mass or 19 to 30% by mass. When the NCO content of component (F) is 10% by mass or more, the coating film tends to have higher hardness. When the NCO content of component (F) is 40% by mass or less, the coating film tends to exhibit good self-healing properties. The above content is based on the total mass of component (F).

[0122] In this specification, the NCO content is the value measured by the method described in JIS K1603-1 (Test method for aromatic isocyanates in polyurethane raw materials).

[0123] The viscosity of the polyisocyanate at 25°C may be 10 to 10,000 mPa·s, and may also be 50 to 8,000 mPa·s, 100 to 5,000 mPa·s, or 200 to 2,000 mPa·s. When the viscosity of the polyisocyanate at 25°C is within the above range, a polyurethane resin-forming composition (coating agent) with even better film-forming properties is more likely to be obtained.

[0124] The content of component (F) may be, for example, 20 to 90% by mass, 30 to 80% by mass, or 40 to 70% by mass, based on the total mass of the polyurethane resin-forming composition.

[0125] The polyurethane resin-forming composition may further contain isocyanate group-containing compounds other than component (F). However, from the viewpoint of obtaining better transparency, the polyurethane resin-forming composition does not need to contain isocyanate group-containing compounds having aromatic rings. The content of isocyanate group-containing compounds having aromatic rings may be 5% by mass or less, or 0% by mass, based on the total mass of the polyurethane resin-forming composition.

[0126] The ratio of the number of moles of isocyanate groups in the isocyanate group-containing compound contained in the polyurethane resin-forming composition to the number of moles of hydroxyl groups in the hydroxyl group-containing compound contained in the polyurethane resin-forming composition (NCO / OH equivalent) may be 0.8 or higher, 0.9 or higher, or 1.0 or higher, from the viewpoint of suppressing excess hydroxyl groups and further improving the durability and mechanical properties of the coating film. The NCO / OH equivalent may be 1.3 or lower, 1.2 or lower, or 1.1 or lower, from the viewpoint of suppressing excess isocyanate groups and further improving the durability and mechanical properties of the coating film. The NCO / OH equivalent may be 0.8 to 1.3, 0.9 to 1.2, or 1.0 to 1.1, from the above viewpoint.

[0127] <Coating Set> Another embodiment of the present disclosure relates to a coating set for preparing the polyurethane resin-forming composition of the above embodiment. The coating set is, for example, a coating set for in-mold coating (in-mold coating set). The coating set comprises a first agent containing the above components (A), (B), (C), and (D), and a second agent containing the above component (F). The first agent may be the polyol composition of the above embodiment. When the coating set consists of a first agent and a second agent, the polyurethane resin-forming composition of the above embodiment can be prepared by mixing the first agent and the second agent.

[0128] The first component of the above-mentioned coating agent set contains components (A), (B), (C), and (D). However, since the additive component (D) is easily soluble in component (A), the first component can be prepared at a relatively low temperature (for example, below 100°C).

[0129] The first and second agents may contain component (E) above, and may also contain other components that can be contained in the polyurethane resin-forming composition. However, from the viewpoint of storage stability, hydroxyl group-containing compounds other than component (A) may be incorporated into the first agent, and isocyanate group-containing compounds other than component (F) may be incorporated into the second agent.

[0130] The coating set may further comprise other agents different from the first and second agents. These other agents may contain other components that can be included in the polyurethane resin-forming composition, and may contain component (E). If the coating set further comprises other agents, the polyurethane resin-forming composition of the above embodiment can be prepared by mixing the first agent, the second agent, and the other agents.

[0131] The viscosity of the first component at 25°C may be 10 to 10,000 mPa·s, and may also be 50 to 8,000 mPa·s, 100 to 5,000 mPa·s, or 200 to 2,000 mPa·s. When the viscosity of the first component at 25°C is within the above range, a polyurethane resin-forming composition (coating agent) with even better film-forming properties is more likely to be obtained.

[0132] The viscosity of the second component at 25°C may be 10 to 10,000 mPa·s, and may also be 50 to 8,000 mPa·s, 100 to 5,000 mPa·s, or 200 to 2,000 mPa·s. When the viscosity of the second component at 25°C is within the above range, a polyurethane resin-forming composition (coating agent) with even better film-forming properties is more likely to be obtained.

[0133] When using the in-mold coating agent set, for example, the first agent, the second agent, and any other agents used may be mixed so that the NCO / OH equivalent is within the range described above.

[0134] <Coating Film> Another embodiment of the present disclosure relates to a coating film comprising a reaction product of the polyurethane resin-forming composition of the above embodiment. Here, the reaction product of the polyurethane resin-forming composition is a reaction product obtained by reacting the components contained in the polyurethane resin-forming composition (at least component (A) and component (F)). Therefore, the coating film contains a polyurethane resin produced by the reaction of at least component (A) and component (F). The coating film may also contain some of the components contained in the polyurethane resin-forming composition (for example, unreacted components).

[0135] The thickness of the coating film is, for example, 1 to 10,000 μm, and may be 5 to 5,000 μm or 10 to 1,000 μm.

[0136] The coating film can be formed by first forming a coating film made of the polyurethane resin-forming composition of the above embodiment, and then reacting the composition. More specifically, it can be formed, for example, by the in-mold coating method described later. Since the reaction of the polyurethane resin-forming composition causes the coating film made of the composition to harden, the coating film made of the polyurethane resin-forming composition and the coating film of the above embodiment can also be referred to as the uncured film and the cured film, respectively.

[0137] The coating film may be provided on a substrate such as a plastic molded product and constitute a part of a component including the substrate (for example, an interior part of an automobile). That is, in another embodiment, the present disclosure provides a component comprising a substrate and the coating film provided on the substrate.

[0138] <In-mold coating method> Another embodiment of the present disclosure relates to an in-mold coating method comprising: preparing a substrate and a mold in which the substrate is placed; injecting the polyurethane resin-forming composition of the above embodiment into the mold; applying the polyurethane resin-forming composition to the surface of the substrate; and reacting the polyurethane resin-forming composition to form a coating film on the surface of the substrate. According to this method, the coating film of the above embodiment can be obtained. The in-mold coating method of this embodiment will be described below with reference to Figure 1.

[0139] Figure 1 is a schematic diagram illustrating one embodiment of the in-mold coating method. In this embodiment of the in-mold coating method, first, a substrate 1 and a mold 2 in which the substrate 1 is placed are prepared (see Figure 1(a)).

[0140] The base material 1 is, for example, a molded body (plastic molded product) made of a plastic material. Examples of plastic materials include acrylic polyol resin, polycarbonate resin, polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polystyrene resin, AS resin, ABS resin, polycarbonate-ABS resin, 6-nylon resin, 6,6-nylon resin, MXD6 nylon resin, polyvinyl chloride resin, polyvinyl alcohol resin, polyurethane resin, phenolic resin, melamine resin, polyacetal resin, chlorinated polyolefin resin, polyolefin resin, polyamide resin, polyetheretherketone resin, polyphenylene sulfide resin, NBR resin, chloroprene resin, SBR resin, SEBS resin, and combinations thereof. The surface of the molded body may be subjected to surface treatment such as corona discharge treatment. Other coating films that can serve as intermediate layers may be formed on the surface of the molded body.

[0141] Mold 2 has a gap 2a for forming a coating film between the inner wall of mold 2 and the base material 1, an opening 2b for injecting the coating agent, and a flow path 2c for supplying the coating agent from the opening 2b to the gap 2a. Mold 2 may be the same mold used to mold the base material 1, and may have an internal structure that is the same shape as the target base material 1. In this case, for example, after injecting a plastic material heated and melted in an injection cylinder into mold 2, cooling and pressurizing to mold the base material 1, the clamping force may be reduced, or the gap between the obtained molded product (base material) and the inner wall of the mold may be slightly opened to provide a gap 2a for forming a coating film between the base material 1 and mold 2.

[0142] Next, the composition 6 (polyurethane resin-forming composition) of the above embodiment is prepared by supplying the first agent 3 and the second agent 4 into the tank 5 and mixing them, and the composition 6 is injected into the mold 2 to coat the surface 1a of the substrate 1 with composition 6 (see Figure 1(b)). When preparing composition 6, the first agent 3 and the second agent 4 may be heated to mix them more uniformly. Also, when injecting composition 6, composition 6 and the mold 2 may be heated to the extent that composition 6 does not become excessively viscous. However, the temperature of composition 6 at the time of injection may be 30°C or less, and the temperature of the mold 2 at the time of injection may be 85°C or less.

[0143] Next, by reacting composition 6, a coating film 7 (e.g., a cured film) containing the reaction products of composition 6 is formed on the surface of the substrate 1 (see Figure 1(c)). The reaction of composition 6 may be carried out by injecting composition 6 into a heated mold. The heating temperature should not exceed the heat resistance of the substrate, and from the viewpoint of coating film formation, it may be 50 to 150°C or 50 to 85°C. In order to allow the reaction of composition 6 to proceed more sufficiently, the coating film may be heated again after the substrate is removed from the mold.

[0144] The contents of this disclosure will be described in more detail below using examples and comparative examples, but this disclosure is not limited to the following examples.

[0145] <Synthesis and Evaluation of Polycarbonate Polyols> (Synthesis Example 1) In a reaction apparatus equipped with a stirrer, thermometer, heating device, and distillation column, 792 g of 3-methyl-1,5-pentanediol (manufactured by Kuraray Co., Ltd.) and 88 g of 1,6-hexanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged as polyol components (mixture of polyols), 638 g of diethyl carbonate (manufactured by Tokyo Chemical Industry Co., Ltd.) was charged as the carbonate component, and 0.05 g of tetrabutoxytitanium was charged as a reaction catalyst. The temperature inside the apparatus was gradually increased to 190°C under a nitrogen stream. When the distillation of ethanol slowed down and the top temperature of the distillation column fell below 50°C, the temperature inside the apparatus was kept at 190°C and the pressure was gradually reduced to 0.1 kPa. The reaction was continued at a pressure of 0.1 kPa for another 5 hours to distill off the ethanol. This synthesized the polycarbonate polyol (PCP) of Synthesis Example 1.

[0146] (Condition Evaluation) The obtained polycarbonate polyol was heated to 100°C, then placed in a transparent glass bottle and left to stand for 24 hours at 25°C. After standing, the polycarbonate polyol was visually observed to see if it had fluidity when the glass bottle was tilted at 25°C. It was confirmed that the polycarbonate polyol had fluidity (i.e., was in a liquid state).

[0147] (Hydroxyl Value Measurement) The hydroxyl value of the polycarbonate polyol obtained in Synthesis Example 1 was evaluated using an acetylation reagent in accordance with JIS K1557-1. Based on the hydroxyl value, the molecular weight of the polycarbonate polyol was calculated using a theoretical value (calculated value) of 2 for the number of hydroxyl groups. The hydroxyl value of the polycarbonate polyol was 226.8 mgKOH / g, and the molecular weight calculated from the hydroxyl value and the number of hydroxyl groups was 495.

[0148] <Examples 1-11 and Comparative Examples 1-7> (Preparation of Polyol Compositions) Components (A) (polyol), (B) (urethane-based metal catalyst), (C) (carbonyl compound), (D) (hindered amine-based light stabilizer), and (E) (ultraviolet absorber) shown in Tables 1-2 were placed in a poly bottle in the mixing ratios (unit: mass%) shown in Tables 1-2. An appropriate amount of nitrogen was flowed into the poly bottle to replace the atmosphere with nitrogen, and then it was sealed. The contents were mixed using a mixing rotor to obtain a polyol composition. In Tables 1-2, "(C) mol / (B) mol" indicates the ratio of the content of component (C) per 1 mol of (B) (unit: mol).

[0149] (Calculation of average hydroxyl value) The average hydroxyl value of component (A) contained in the polyol composition was calculated using the following formula. The results are shown in Tables 1 and 2. Average hydroxyl value (unit: mgKOH / g) = (Hydroxyl value of component (A) 1 × Mass of component (A) 1 added + Hydroxyl value of component (A) 2 × Mass of component (A) 2 added) / Total mass of component (A) added Here, component (A) 1 and component (A) 2 refer to the respective materials blended as component (A). For example, in Example 1, component (A) 1 is "PCP" in the table, and component (A) 2 is "1,3-BG" in the table.

[0150] (Evaluation of viscosity and storage stability of polyol composition) Polyol compositions stored within 24 hours at 23-25°C after preparation were placed in glass bottles (manufactured by AS ONE Corporation, standard bottle No. 11), and the glass bottles were immersed in a constant temperature water bath at 25°C for 5 hours. Subsequently, the viscosity of the polyol composition at 25°C (initial viscosity "V1", unit: mPa·s) was measured using a B-type viscometer (manufactured by Toki Sangyo Co., Ltd., TVB-22L).

[0151] Meanwhile, the viscosity of the polyol composition stored for four weeks in an explosion-proof constant temperature bath at 45°C was similarly measured at 25°C (viscosity after 4 weeks of storage at 45°C "V2", unit: mPa·s). The four-week storage was carried out by placing 200 g of the polyol composition into a 250 mL square can (manufactured by Seibu Container Co., Ltd.), replacing the atmosphere inside the can with nitrogen, sealing it, and storing the can in an explosion-proof constant temperature bath at 45°C for four weeks.

[0152] The viscosity change rate of the polyol composition after storage at 45°C for 4 weeks was calculated using the initial viscosity "V1" and the viscosity "V2" after storage at 45°C for 4 weeks, using the following formula: Viscosity change rate (unit: %) = 100 × [(V2 - V1) / (V1)]

[0153] [Evaluation Criteria for Viscosity Change Rate] The viscosity change rate was evaluated according to the following criteria: • A: Absolute value of viscosity change rate is less than 6 • B: Absolute value of viscosity change rate is 6 or more but less than 10 • C: Absolute value of viscosity change rate is 10 or more but less than 13 • D: Absolute value of viscosity change rate is 13 or more

[0154] (Preparation and Reactivity Evaluation of Polyurethane Resin-Forming Composition) As the first agent, a polyol composition was prepared and stored within 24 hours at 23-25°C after preparation. As the second agent, Coronate HXLV (C-HXLV in the table), which is component (F) (polyisocyanate), was prepared. The first and second agents were placed in a stirring container for Awatori Rentaro (manufactured by Shinky Co., Ltd., No. 001, capacity 150 mL) in the mixing ratios (unit: mass%) shown in Tables 1 and 2, with a total amount of 57 g. The ratio of OH groups of component (A) (polyol) to NCO groups of component (F) (polyisocyanate) was set to NCO / OH = 1.05. Immediately after preparation, the mixture of the first and second agents was mixed for 30 seconds at a speed of 2000 rpm in a rotary-orbit mixer (manufactured by Thinky Co., Ltd., product name: Awatori Rentaro ARE-310) to prepare a liquid polyurethane resin-forming composition. Then, with the time immediately after 30 seconds of mixing set as 0 seconds, the fluidity near the surface of the polyurethane resin-forming composition was checked with a wooden stirrer every 5 seconds, and the time until the polyurethane resin-forming composition became solid (initial reaction time "R1", in seconds) was measured.

[0155] Polyol compositions stored in an explosion-proof constant temperature chamber at 45°C for four weeks were also left to stand for 16 to 24 hours in an environment of 23 to 25°C, and then mixed with the second agent (Coronate HXLV) in the same manner as above to prepare a polyurethane resin-forming composition. Subsequently, the time until the polyurethane resin-forming composition became solid (reaction time "R2" after storage at 45°C for four weeks, in seconds) was measured in the same manner as above.

[0156] The rate of change in the reactivity of a polyurethane resin-forming composition after storing a polyol composition at 45°C for 4 weeks was calculated using the following formula, based on the initial reaction time "R1" and the reaction time after 4 weeks of storage at 45°C "R2": Rate of change in reactivity (%) = 100 × [(R2 - R1) / (R1)]

[0157] [Criteria for evaluating initial reactivity] Initial reactivity was evaluated according to the following criteria. Note that if the evaluation of viscosity change rate was D, this evaluation was not performed. ・A: R1 is 5 seconds or more and 60 seconds or less ・B: R1 is greater than 60 seconds and 90 seconds or less ・C: R1 is greater than 90 seconds and 120 seconds or less ・D: R1 is less than 5 seconds or greater than 120 seconds

[0158] [Evaluation Criteria for Reactivity Change Rate] The reactivity change rate was evaluated according to the following criteria. Note that if the initial reactivity evaluation result was D, this evaluation was not performed. ・A: Absolute value of reactivity change rate is 20 or less ・B: Absolute value of reactivity change rate is greater than 20 and 30 or less ・C: Absolute value of reactivity change rate is greater than 30 and 40 or less ・D: Absolute value of reactivity change rate is greater than 40

[0159] (Preparation of Polyurethane Resin-Forming Composition and Fabrication of Coating Film) The first and second agents were mixed for 30 seconds in the same manner as in the reaction evaluation described above to prepare a liquid polyurethane resin-forming composition. Next, the coating liquid made from the obtained polyurethane resin-forming composition was applied to a white steel plate which served as the substrate. At this time, two guides with a height of 600 μm were placed on the substrate, and the coating liquid was poured between the two guides to adjust the cured film thickness to 600 μm. In order to reproduce the conditions of in-mold coating, release glass was placed on the guides so as to cover the coating film (uncured film made from the coating liquid), and then the coating film was cured at 80°C for 1 hour. For coating films made from polyurethane resin-forming compositions that received a D rating for initial reactivity in the reaction evaluation described above, the film was cured at 80°C for 20 hours. After that, the film was cured at 50°C for 6 hours to form a coating film (cured film) containing the reaction products of the polyurethane resin-forming composition. The laminate made from the substrate and coating film (cured film) obtained in this way was used as a test piece and the following evaluation was performed.

[0160] (Weathering Test) The test specimens obtained above were subjected to a 576-hour weathering test using a QUV accelerated weathering tester (manufactured by Q-Lab Corporation) under the following conditions: [Conditions] - Standard: ASTM G154 - Cycle No. 5 (Lamp: UVB-313, Irradiance: 0.62 W / m ２ (Control wavelength: 310 nm, Temperature: 80°C during light irradiation / 50°C during dew, Cycle time: 20 hours during light irradiation / 4 hours during dew)

[0161] (Gloss Retention Evaluation) Using Microtrigloss (manufactured by Big Chemie Co., Ltd.), the gloss of the test specimens obtained above at 60° was measured before and after the weathering test, and the gloss retention rate was calculated using the following formula: Gloss Retention Rate (%) = 100 × [(Gloss of test specimen after weathering test) / (Gloss of test specimen before weathering test)]

[0162] [Evaluation Criteria for 60° Gloss Retention Rate] The 60° gloss retention rate was evaluated according to the following criteria: • A: Gloss retention rate of 90% or more • B: Gloss retention rate of 80% or more but less than 90% • C: Gloss retention rate of 60% or more but less than 80% • D: Gloss retention rate of less than 60%

[0163]

[0164]

[0165] The details of the materials shown in Tables 1 and 2 are as follows: • PCP: Polycarbonate polyol from Synthesis Example 1 • PEP: Polyester polyol (manufactured by Kuraray Co., Ltd., product name: Kuraray Polyol P-510, number of hydroxyl groups: 2, hydroxyl value: 226 mg KOH / g) • 1,3-BG: 1,3-Butanediol (manufactured by Daicel Corporation, molecular weight: 90.12, number of hydroxyl groups: 2, hydroxyl value: 1245 mg KOH / g) • MPD: 2-Methyl-1,3-Propanediol (manufactured by Sigma-Aldrich, molecular weight: 90.12, number of hydroxyl groups: 2, hydroxyl value: 1245 mg KOH / g) • DBTDL: Dibutyltin dilaurate (manufactured by Nitto Chemical Co., Ltd., product name: Neostan U-100, molecular weight: 631.56) • Acetic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., molecular weight: 60.05) • Acetic anhydride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., molecular weight: 102.09) • 2-ethylhexanoic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., molecular weight: 144.21) • Acetylacetone (manufactured by Daicel Corporation, molecular weight: 100.12) • Methyl acetoacetate (manufactured by Daicel Corporation) • Phosphoric acid (manufactured by Kishida Chemical Co., Ltd.) • HALS(1): Tinuvin 292 (manufactured by BASF, a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate (molecular weight 509) and methyl(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate (molecular weight 370), N-CH ３ HALS type) ・Triazine (1): Tinuvin 400 (manufactured by BASF, a 1-methoxy-2-propanol solution of a mixture of 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine and 2-[4-[(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine) ・C-HXLV: Isocyanurate modified form of hexamethylene diisocyanate (manufactured by Tosoh Corporation, trade name: Coronate HXLV, NCO content: 23.4% by mass, viscosity at 25°C: 1100 mPa·s, liquid at 25°C)

[0166] 1...Substrate, 1a...Surface of the substrate, 2...Mold, 2a...Gap, 2b...Opening, 2c...Flow channel, 3...First agent, 4...Second agent, 5...Tank, 6...Polyurethane resin forming composition, 7...Coating film.

Claims

1. A polyol composition comprising: (A) a polyol comprising at least one selected from the group consisting of polycarbonate polyols and polyester polyols; (B) a urethane metal catalyst; (C) at least one carbonyl compound selected from the group consisting of carboxylic acids, carboxylic acid anhydrides and β-diketones; and (D) a hindered amine-based light stabilizer, wherein the content of volatile organic compounds is 0 to 10% by mass.

2. (E) The polyol composition according to claim 1, further containing an ultraviolet absorber.

3. The polyol composition according to claim 1, wherein component (C) comprises at least one selected from the group consisting of carboxylic acids and β-diketones.

4. The polyol composition according to claim 1, wherein the content of component (C) is 0.1 to 30.0 mol per 1 mol of component (B).

5. A polyurethane resin-forming composition comprising: (A) a polyol comprising at least one selected from the group consisting of polycarbonate polyols and polyester polyols; (B) a urethane metal catalyst; (C) at least one carbonyl compound selected from the group consisting of carboxylic acids, carboxylic acid anhydrides and β-diketones; (D) a hindered amine light stabilizer; and (F) a polyisocyanate, wherein the content of volatile organic compounds is 0 to 10% by mass.

6. The polyurethane resin-forming composition according to claim 5, which is used as a coating agent for in-mold coating.

7. A coating agent set for preparing the polyurethane resin-forming composition described in claim 5, comprising: a first agent containing component (A), component (B), component (C), and component (D); and a second agent containing component (F).

8. A coating film comprising a reaction product of the polyurethane resin-forming composition described in claim 5.

9. A method for forming a coating film, comprising: preparing a substrate and a mold in which the substrate is placed; injecting the polyurethane resin-forming composition described in claim 5 into the mold and applying the polyurethane resin-forming composition to the surface of the substrate; and reacting the polyurethane resin-forming composition to form a coating film on the surface of the substrate.

Images