Decorative film and article

Abstract

The present invention provides: a decorative film which has a highly reliable hard coating layer that has both high stretchability capable of coping with deep drawing applications, and chemical resistance and scratch resistance; and an article which includes the hard coating layer and a body to be decorated. This decorative film (101) has, on a base material layer (1), a hard coating layer (10) which is a cured product of a thermosetting composition that contains a (meth)acrylic copolymer (A) having a hydroxyl group, an isocyanate-based curing agent (B), and inorganic oxide fine particles (C). The (meth)acrylic copolymer (A) is composed of a unit derived from a monomer having a hydroxyl group and a unit derived from another monomer, and satisfies a specific condition.

Description

Decorative films and articles

[0001] The present disclosure relates to a decorative film having a hard coat layer on a substrate layer, and an article including the hard coat layer and an object to be decorated.

[0002] Resin molded products are widely used in a variety of applications, such as the interior and exterior of automobiles, mobile information terminal devices such as smartphones, notebook computers, and home appliances. Furthermore, the surface of resin molded products is often coated with paint or decorative films to enhance their design. A variety of decorative films have been proposed.

[0003] For example, Patent Document 1 discloses a multilayer body in which a layer made of an acrylic resin (A) and a layer made of an aliphatic polycarbonate resin (B) are laminated together.

[0004] Patent Document 2 discloses a multilayer film in which a layer (B) of a methacrylic resin material is laminated on at least one surface of a layer (A) of a polycarbonate resin material, with the objective of providing a resin film that is crack-resistant, has excellent whitening resistance, has high surface hardness, and is easy to mold. The layer (B) of the methacrylic resin material contains 85 to 100 parts by mass of methacrylic resin and 0 to 15 parts by mass of acrylic rubber particles, and is characterized in that the glass transition temperature (Tg) of the methacrylic resin material and the Tg of the polycarbonate resin material have a predetermined relationship.

[0005] Patent Document 3 describes a decorative film that is composed of a laminate including a hard coat layer made of a cured product of a thermosetting coating material that contains an acrylic copolymer (A) having a hydroxyl group and an isocyanate curing agent (B), and a substrate layer.

[0006] Patent Document 4 discloses a laminated film for decorating three-dimensional molded products, which has a clear coating film layer (A) and a design layer (B) made of an energy ray-curable coating film, and further has an adhesive layer (C), or has a clear coating film layer (A) and a design layer (B-C) that also functions as an adhesive layer, and has a coating film strength within a specific range.

[0007] Patent Document 5 describes a molded article made of an acrylic resin molding material having a polymer (X) containing a specific amount of methyl methacrylate as a monomer unit, with the objective of providing a molded article that is excellent in scratch resistance and transparency.

[0008] Patent Document 6 discloses a multilayer sheet composed of a laminate having a polycarbonate resin layer as a substrate and a thermoplastic acrylic resin layer containing a specific amount of silica particles with an average particle size of 0.1 to 2 μm as the outermost layer of the substrate.

[0009] Patent Document 7 aims to provide a laminate containing an acrylic resin film with excellent formability, and discloses a method for producing a laminate, which includes a step of forming a hard coat layer containing a urethane acrylate resin on at least one surface of a specific acrylic resin film, and a step of forming a low refractive index layer on the hard coat layer, which contains an acrylate resin containing 40% or more of hollow silica fine particles having a particle diameter of less than 100 nm.

[0010] JP 2011-161871 A JP 2010-125645 A JP 2017-186500 A JP 2022-123593 A JP 2017-014395 A International Publication No. 2022 / 054693 International Publication No. 2022 / 185815

[0011] Decorative films require high levels of three-dimensional formability. In recent years, decorative films with excellent three-dimensional formability, particularly those suitable for deep drawing applications such as film insert molding, have become increasingly popular. Furthermore, because decorative films are formed on the surface of substrates, they require not only excellent design but also chemical resistance. Abrasion resistance, which allows them to withstand repeated friction and contact, and scratch resistance, which prevents surface scratches and abrasions, are also important. Abrasion resistance is evaluated based on the amount of abrasion of the coating film, measuring the abrasion of the coating film itself. Scratch resistance, on the other hand, is evaluated based on the number of scratches on the coating film, which is a more stringent evaluation standard. Therefore, scratch resistance is considered to be technically more difficult to achieve than abrasion resistance. While decorative films with excellent abrasion resistance have been proposed, the market desperately needs decorative films with excellent scratch resistance. A simple way to improve chemical resistance and scratch resistance is to increase the thickness of the hard coat layer. However, the market demands thinner decorative films for weight reduction, environmental impact reduction, and economic efficiency.

[0012] The present disclosure has been made in view of the above background, and aims to provide a decorative film having a highly reliable hard coat layer that has high stretchability suitable for deep drawing applications such as film insert molding, and that has both chemical resistance and scratch resistance even when thinned. Another aim is to provide an article formed using the decorative film.

[0013] In order to achieve the above object, the present inventors conducted extensive research and found that the problems of the present disclosure can be solved in the following manner, leading to the completion of the present invention. [1]: A decorative film having a hard coat layer on a substrate layer, wherein the hard coat layer is a cured product of a thermosetting composition containing a (meth)acrylic copolymer (A) having a hydroxyl group, an isocyanate-based curing agent (B), and inorganic oxide fine particles (C), and the (meth)acrylic copolymer (A) is a copolymer composed of units derived from a monomer having a hydroxyl group and units derived from other monomers, and the decorative film satisfies the following conditions (I) to (VI): (I) The hard coat layer has a total light transmittance of 40% or more and a diffuse transmittance of 70% or less. (II) The tensile strength of the hard coat layer in an atmosphere of 25°C and a relative humidity of 50% is 15 to 100 N / mm ２(III) The (meth)acrylic copolymer (A) has a hydroxyl value of 20 to 100 mgKOH / g, an acid value of 0 to 20 mgKOH / g, a glass transition temperature of 30 to 120°C, a weight-average molecular weight of 50,000 to 200,000, and a weight-average molecular weight / number-average molecular weight ratio of 2.0 to 10. (IV) In the (meth)acrylic copolymer (A), the content of units derived from a monomer having one hydroxyl group is 50 mol% or more out of 100 mol% of units derived from a monomer having a hydroxyl group. (V) 56 mol% or more of the hydroxyl groups in the (meth)acrylic copolymer (A) are primary hydroxyl groups. (VI) The average dispersed particle diameter D50 of the inorganic oxide fine particles (C) in the thermosetting composition is 0.01 to 5 μm. [2]: The decorative film according to [1], wherein the thermosetting composition further contains a silicone-based surface conditioner (D). [3]: The decorative film according to [1] or [2], characterized in that the average dispersed particle diameter D50 of the inorganic oxide fine particles (C) in the thermosetting composition is 0.01 to 0.2 μm or 1 to 3 μm. [4]: ​​The decorative film according to any one of [1] to [3], characterized in that the thickness of the hard coat layer is 4 to 15 μm. [5]: An article comprising an object to be decorated and a hard coat layer, wherein the hard coat layer is a cured product of a thermosetting composition containing a (meth)acrylic copolymer (A) having a hydroxyl group, an isocyanate-based curing agent (B), and inorganic oxide fine particles (C), and the (meth)acrylic copolymer (A) is a copolymer consisting of units derived from a monomer having a hydroxyl group and units derived from other monomers, and the article satisfies the following conditions (I) to (VI): (I) The hard coat layer has a total light transmittance of 40% or more and a diffuse transmittance of 70% or less. (II) The hard coat layer has a tensile strength of 15 to 100 N / mm under an atmosphere of 25°C and a relative humidity of 50%. ２(III) The (meth)acrylic copolymer (A) has a hydroxyl value of 20 to 100 mgKOH / g, an acid value of 0 to 20 mgKOH / g, a glass transition temperature of 30 to 120°C, a weight average molecular weight of 50,000 to 200,000, and a weight average molecular weight / number average molecular weight ratio of 2.0 to 10. (IV) In the (meth)acrylic copolymer (A), the content of units derived from monomers having one hydroxyl group is 50 mol% or more out of 100 mol% of units derived from monomers having a hydroxyl group. (V) 56 mol% or more of the hydroxyl groups in the (meth)acrylic copolymer (A) are primary hydroxyl groups. (VI) The average dispersed particle diameter D50 of the inorganic oxide fine particles (C) in the thermosetting composition is 0.01 to 5 μm.

[0014] The present disclosure has the excellent effect of providing a decorative film having a highly reliable hard coat layer that has high stretchability suitable for deep drawing applications such as film insert molding, and that has both chemical resistance and scratch resistance even when thinned. Also, the present disclosure has the excellent effect of providing an article formed using the decorative film.

[0015] Schematic cross-sectional views showing configuration examples of a decorative film according to the present disclosure. Schematic cross-sectional views showing configuration examples of a decorative film according to the present disclosure. Schematic cross-sectional views showing configuration examples of a decorative film according to the present disclosure. Schematic cross-sectional views showing configuration examples of a decorative film according to the present disclosure. Schematic cross-sectional views showing configuration examples of a decorative film according to the present disclosure. Schematic cross-sectional views showing configuration examples of a decorative film according to the present disclosure. Schematic cross-sectional views showing configuration examples of a decorative film according to the present disclosure.

[0016] An example of an embodiment to which the present disclosure is applied will be described below. The numerical values ​​specified in this specification are values ​​determined by the methods disclosed in the embodiments or examples. Furthermore, the numerical values ​​"A to B" specified in this specification include numerical value A as the lower limit and numerical value B as the upper limit. Furthermore, "sheet" in this specification includes "sheet" as defined in JIS as well as "film." Unless otherwise noted, the various components specified in this specification may each be used independently, either alone or in combination of two or more types. Furthermore, "(meth)acrylic" means acrylic and / or methacrylic, and "(meth)acrylate" means acrylate and / or methacrylate.

[0017] The decorative film of this embodiment (hereinafter also referred to as the present decorative film) has a hard coat layer on a base layer. The hard coat layer is a cured product of a thermosetting composition containing a (meth)acrylic copolymer (A) having a hydroxyl group (hereinafter also simply referred to as the (meth)acrylic copolymer (A)), an isocyanate-based curing agent (B), and inorganic oxide fine particles (C). The (meth)acrylic copolymer (A) is a copolymer consisting of units derived from a monomer having a hydroxyl group and units derived from other monomers. The present decorative film satisfies the following conditions (I) to (VI). (I) The hard coat layer has a total light transmittance of 40% or more and a diffuse transmittance of 70% or less. (II) The tensile strength of the hard coat layer in an atmosphere of 25°C and a relative humidity of 50% is 15 to 100 N / mm ２ (III) The (meth)acrylic copolymer (A) has a hydroxyl value of 20 to 100 mgKOH / g, an acid value of 0 to 20 mgKOH / g, a glass transition temperature of 30 to 120°C, a weight average molecular weight of 50,000 to 200,000, and a weight average molecular weight / number average molecular weight ratio of 2.0 to 10. (IV) In the (meth)acrylic copolymer (A), the content of units derived from monomers having one hydroxyl group is 50 mol% or more out of 100 mol% of units derived from monomers having a hydroxyl group. (V) 56 mol% or more of the hydroxyl groups in the (meth)acrylic copolymer (A) are primary hydroxyl groups. (VI) The average dispersed particle diameter D50 of the inorganic oxide fine particles (C) in the thermosetting composition is 0.01 to 5 μm.

[0018] The hard coat layer is obtained by coating and curing a thermosetting composition containing a hydroxyl group-containing (meth)acrylic copolymer (A), an isocyanate-based curing agent (B), and inorganic oxide fine particles (C). This hard coat layer achieves both moldability and surface hardness, which are not possible with acrylic resin films obtained by melt extrusion of thermoplastic acrylic resins. Furthermore, it also ensures light resistance, which is not possible with UV-curable acrylic resin films.

[0019] In order to maintain good moldability during three-dimensional molding, it is advantageous to have high tensile strength at break and elongation. On the other hand, it is necessary to maintain excellent chemical resistance, scratch resistance, and hardness. Taking these balances into consideration, high molecular weight resins with Mw of approximately 200,000 to 1,000,000 have been used for the hard coat layer. Furthermore, a thicker hard coat layer is advantageous for chemical resistance and scratch resistance, and conventionally, thicknesses of 20 μm, 50 μm, 100 μm, etc. have been used for the hard coat layer.

[0020] However, surprisingly, the decorative film of the present disclosure exhibits excellent chemical resistance, abrasion resistance, and hardness, not only when the (meth)acrylic copolymer (A) has a relatively high molecular weight (Mw) of 100,000 or more but 200,000 or less, but also when the (meth)acrylic copolymer (A) has a relatively low molecular weight (Mw) of 50,000 or more but less than 100,000. This is believed to be primarily due to the use of inorganic oxide fine particles (C) having an average dispersed particle diameter D50 of 0.01 to 5 μm in combination with the (meth)acrylic copolymer (A). In addition to the high extensibility of the (meth)acrylic copolymer (A) having a relatively low molecular weight (Mw) of 50,000 or more but less than 100,000, the use of inorganic oxide fine particles (C) in combination provides a film with excellent film strength. Note that hardness is an indicator of the hardness of the coating film and is evaluated by the pencil hardness test described below. Pencil hardness is determined by scratching the coating film in the depth direction, and is therefore greatly influenced by the crosslink density of the entire coating film. It is also greatly influenced by the composition of the substrate. On the other hand, scratch resistance is an index of scratch resistance on the coating film surface, and is evaluated by a scratch resistance test (using steel wool, etc.) described below. Pencil hardness and scratch resistance tests have in common that the coating film is scratched by applying a load, but the parts evaluated are completely different.

[0021] The decorative film of the present disclosure exhibits excellent chemical resistance and scratch resistance not only at thicknesses exceeding 15 μm and not exceeding 200 μm, but also at thicknesses of 4 μm or more and not exceeding 15 μm. This is believed to be primarily due to the use of inorganic oxide microparticles (C) having an average dispersed particle diameter D50 of 0.01 to 5 μm in combination with the (meth)acrylic copolymer (A). Due to these synergistic effects, the decorative film of the present disclosure can provide a highly reliable decorative film that exhibits excellent chemical resistance and scratch resistance even when thinned. This makes the film suitable for deep drawing applications such as film insert molding.

[0022] <(Meth)acrylic Copolymer (A) Having a Hydroxy Group> The (meth)acrylic copolymer (A) having a hydroxyl group is obtained by copolymerizing a monomer having a hydroxyl group (hereinafter also referred to as a "hydroxyl group-containing monomer") with another monomer not having a hydroxyl group (hereinafter also referred to as an "other monomer"). That is, the (meth)acrylic copolymer (A) is a copolymer comprising a unit derived from the monomer having a hydroxyl group and a unit derived from the other monomer.

[0023] The content of the monomer having one hydroxyl group is 50 mol% or more out of 100 mol% of the monomer having a hydroxyl group that is used in the polymerization of the (meth)acrylic copolymer (A) and that constitutes the (meth)acrylic copolymer (A). Since the monomer charge ratio is approximately equal to the composition ratio of the polymer, the content of the unit derived from the monomer having one hydroxyl group is essentially 50 mol% or more out of 100 mol% of the units derived from the monomer having a hydroxyl group that constitutes the (meth)acrylic copolymer (A). By having this content of 50 mol% or more, the crosslinking uniformity within the hard coat layer is increased, contributing to improved chemical resistance and scratch resistance.

[0024] Examples of monomers having one hydroxyl group include hydroxyalkyl (meth)acrylates and compounds in which ε-caprolactone is added to the hydroxyalkyl (meth)acrylates. Among these, hydroxyalkyl (meth)acrylates are preferred. Specific examples are described below, but the present disclosure is not limited to the following examples.

[0025] Specific examples of hydroxyalkyl (meth)acrylates include hydroxyalkyl (meth)acrylates in which the alkyl group has 1 to 4 carbon atoms, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Specific examples of compounds in which ε-caprolactone is added to hydroxyalkyl (meth)acrylates include ε-caprolactone adducts of hydroxyalkyl (meth)acrylates in which the number of carbon atoms is 1 to 4, such as an ε-caprolactone 1-mol adduct of 2-hydroxyethyl (meth)acrylate, an ε-caprolactone 2-mol adduct of 2-hydroxyethyl (meth)acrylate, and an ε-caprolactone 3-mol adduct of 2-hydroxyethyl (meth)acrylate.

[0026] Examples of monomers having two or more hydroxyl groups include 1,1-dihydroxymethyl(meth)acrylate, 1,2-dihydroxyethyl(meth)acrylate, 2,2-dihydroxyethyl(meth)acrylate, and 2,3-dihydroxypropyl(meth)acrylate. Furthermore, as a monomer having two or more hydroxyl groups, a monomer obtained by ring-opening the epoxy group may be used, which is obtained by reacting a (meth)acryloyl monomer having an epoxy group in one molecule with a compound having one functional group reactive with an epoxy group and a hydroxyl group in one molecule or with water.

[0027] At least 56 mol% of the hydroxyl groups in the (meth)acrylic copolymer (A) are primary hydroxyl groups. That is, the type and amount of hydroxyl group-containing monomers are selected and polymerized so that the proportion of primary hydroxyl groups in the hydroxyl groups in the (meth)acrylic copolymer (A) falls within the above range. The proportion of primary hydroxyl groups is preferably 80 mol% or more, more preferably 90 mol% or more. Compared to secondary and tertiary hydroxyl groups, primary hydroxyl groups are more reactive with the isocyanate-based curing agent (B). Therefore, by increasing the proportion of primary hydroxyl groups, unreacted components are less likely to remain in the cured coating film, improving chemical resistance and scratch resistance. The type and amount of hydroxyl groups in the (meth)acrylic copolymer (A) can be determined from the amount (mol) of each hydroxyl group-containing monomer used to form the (meth)acrylic copolymer (A) and the functional groups of the primary and non-primary hydroxyl groups in each monomer.

[0028] The hydroxyl value of the (meth)acrylic copolymer (A) is 20 to 100 mgKOH / g. When the hydroxyl value of the (meth)acrylic copolymer (A) is 20 mgKOH / g or more, the durability of the cured film can be ensured, and when the hydroxyl value is 100 mgKOH / g or less, the moldability of the cured film can be ensured. From the viewpoint of adhesion to the substrate, for example, when the thermosetting composition is coated and laminated on a polycarbonate-based substrate layer, the hydroxyl value of the (meth)acrylic copolymer (A) is preferably 50 mgKOH / g or less. A hydroxyl value of 50 mgKOH / g or less ensures good adhesion between the hard coat layer and the polycarbonate-based substrate layer. Furthermore, when using other substrates, the hydroxyl value is more preferably 90 mgKOH / g or less.

[0029] The other monomer that does not have a hydroxyl group is not particularly limited. Specific examples of the other monomer will be described below. Examples of alkyl (meth)acrylates include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isoamyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and tert-butylhexyl (meth)acrylate, as well as 2-acetoacetoxyethyl (meth)acrylate and phenoxyethyl (meth)acrylate. Examples of monomers having an alicyclic hydrocarbon group include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, cyclododecyl (meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, etc. Examples of monomers having an epoxy group include glycidyl (meth)acrylate, α-methylglycidyl acrylate, α-methylglycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, etc.

[0030] The (meth)acrylic copolymer (A) having a hydroxyl group is preferably one obtained by polymerizing a methacrylate monomer among the various monomers mentioned above.

[0031] The method for polymerizing the monomer is not particularly limited. For example, solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization are exemplified. Among these, solution polymerization is preferred because the resulting reaction mixture can be used as is.

[0032] An example of a method for preparing the (meth)acrylic copolymer (A) by solution polymerization will be described below, although the production method of the present disclosure is not limited to the following method.

[0033] The solvent used in solution polymerization of the monomers is not particularly limited. Examples include aromatic solvents such as toluene and xylene; alcohol solvents such as n-butyl alcohol, propylene glycol monomethyl ether, diacetone alcohol, and ethyl cellosolve; ester solvents such as ethyl acetate, butyl acetate, and cellosolve acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; and dimethylformamide. The amount of solvent may be appropriately determined depending on the concentration of the monomer mixture, the molecular weight of the desired (meth)acrylic copolymer (A), and the like.

[0034] The polymerization initiator is not particularly limited, but specific examples include 2,2'-azobis-(2-methylbutyronitrile), tert-butylperoxy-2-ethylhexanoate, 2,2'-azobisisobutyronitrile, benzoyl peroxide, and di-tert-butyl peroxide. The amount of the polymerization initiator is typically preferably 0.01 to 30 parts by mass, and more preferably 0.05 to 10 parts by mass, per 100 parts by mass of the monomer mixture. When the weight average molecular weight (Mw) is set to 50,000 or more as in the present disclosure, the amount of the polymerization initiator is preferably 0.05 to 1 part by mass per 100 parts by mass of the monomer mixture.

[0035] The polymerization temperature when polymerizing the monomers is usually preferably 40 to 200° C., more preferably 40 to 160° C. When the weight average molecular weight (Mw) is to be 50,000 or more, the polymerization temperature is preferably 90° C. or less.

[0036] The polymerization time of the monomers is appropriately selected depending on the polymerization temperature, the composition of the monomer mixture, the type and amount of the polymerization initiator, and the like.

[0037] The (meth)acrylic copolymer (A) may have an acid value. Having an acid value promotes the reaction between hydroxyl groups and isocyanate groups in the isocyanate curing agent (B), thereby obtaining a cured film with high durability. When an acid value is imparted, the acid value of the (meth)acrylic copolymer (A) is set to 20 mgKOH / g or less. By setting the acid value to 20 mgKOH / g or less, durability can be imparted without impairing moldability. The acid value is more preferably 15 mgKOH / g or less. A method of imparting an acid value to the (meth)acrylic copolymer (A) may be to use a monomer having an acid value as one of the other monomers. Examples of monomers having an acid value include (meth)acrylic acid, maleic anhydride, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl phthalic acid, 2-(meth)acryloyloxyethyl acid phosphate, etc. Among these, (meth)acrylic acid is preferred.

[0038] The glass transition temperature (Tg) of the (meth)acrylic copolymer (A) is 30 to 120°C, preferably 50 to 90°C. A Tg of 30°C or higher provides good hardness and scratch resistance, while a Tg of 120°C or lower provides good moldability. The Tg of the (meth)acrylic copolymer (A) can be adjusted by the type and compositional ratio of other monomers copolymerized with the hydroxyl group-containing monomer and the acidic functional group-containing monomer. Note that the Tg referred to here refers to the Tg measured by differential scanning calorimetry (DSC) for a resin with a 100% solids content obtained by drying a solution of the (meth)acrylic copolymer (A).

[0039] The weight-average molecular weight (Mw) of the (meth)acrylic copolymer (A) is 50,000 to 200,000. By ensuring that the Mw is 200,000 or less, gel formation is prevented, resulting in a hard coat layer with excellent surface smoothness. The upper limit of the Mw is preferably, for example, 150,000, 120,000, 100,000, or 98,000. The lower limit of the Mw is 50,000, preferably, for example, 60,000. The reason why a (meth)acrylic copolymer with a Mw of 50,000 or more and 200,000 or less can significantly improve dispersibility in a thermosetting composition is thought to be that this facilitates preparation of a low-viscosity coating solution in the process of forming the hard coat layer, thereby improving the quality of the coating film. Furthermore, by using inorganic oxide fine particles (C) with excellent dispersibility, a highly reliable decorative film with excellent surface hardness and high scratch resistance can be provided.

[0040] The polydispersity (weight average molecular weight / number average molecular weight) of the (meth)acrylic copolymer (A) is 2.0 to 10. When comparing polymers with similar weight average molecular weights, polymers with low polydispersity contain relatively few low molecular weight components, while polymers with high polydispersity contain relatively many low molecular weight components. The polymer may also contain molecules that are not directly involved in the curing reaction. Among molecules that are not directly involved in the curing reaction, low molecular weight components act as plasticizers, so the polydispersity significantly affects the physical properties of the cured film. That is, a polydispersity of 2.0 or more appropriately reduces the crosslink density of the cured coating film, improving its moldability. On the other hand, a polydispersity of 10 or less appropriately suppresses the plasticity of the cured coating film, maintaining its scratch resistance. The polydispersity is more preferably 2.0 to 8.0, and even more preferably 2.0 to 5.0.

[0041] In order to make the weight average molecular weight (Mw) of the (meth)acrylic copolymer (A) 50,000 or more, methods such as (1) reducing the amount of initiator, (2) lowering the reaction temperature, (3) increasing the monomer concentration, and (4) using a solvent with low chain transfer property can be used. These methods can be used alone or in combination.

[0042] <Isocyanate-Based Curing Agent (B)> The isocyanate-based curing agent (B) reacts with the hydroxyl groups, which are crosslinkable functional groups, in the (meth)acrylic copolymer (A) having the aforementioned hydroxyl groups to form a crosslinked cured resin layer. The blending ratio of the (meth)acrylic copolymer (A) and the isocyanate-based curing agent (B) in the thermosetting composition for forming the hard coat layer is preferably such that the molar ratio (NCO / OH) of the isocyanate groups in the isocyanate-based curing agent (B) to the hydroxyl groups in the (meth)acrylic copolymer (A) is 0.1 to 3.5. By providing 0.1 mol or more of isocyanate groups per mol of hydroxyl groups in the (meth)acrylic copolymer (A), the crosslinking reaction between the (meth)acrylic copolymer (A) and the isocyanate-based curing agent (B) proceeds, resulting in an acrylic resin layer with excellent scratch resistance that cannot be obtained with a simple thermoplastic acrylic extrusion film. By having 3.5 mol or less of isocyanate groups per 1 mol of hydroxyl groups, excessive crosslinking reaction is suppressed, making it suitable for molding in applications where a thicker film (thickness exceeding 15 μm) is deep drawn.

[0043] It is important that the isocyanate-based curing agent (B) has two or more isocyanate groups in one molecule, and examples thereof include aromatic isocyanates, aliphatic isocyanates, and alicyclic isocyanates. Aliphatic isocyanate-based curing agents are preferred in terms of preventing yellowing of the molded decorative film. The isocyanate-based curing agent (B) can be used alone or in combination with two or more other types. Other curing agents that react with hydroxyl groups may also be used as long as they do not affect the physical properties of the decorative film of the present disclosure.

[0044] Examples of aromatic isocyanates include 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, and 4,4',4"-triphenylmethane triisocyanate. Examples of aliphatic isocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate. Examples of alicyclic isocyanates include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and 1,4-bis(isocyanatomethyl)cyclohexane.

[0045] The isocyanate-based curing agent (B) is preferably used in the form of an adduct between the above-mentioned isocyanate and a polyol compound such as trimethylolpropane, a biuret or isocyanurate of the above-mentioned isocyanate, or an adduct between the above-mentioned isocyanate and a known polyether polyol, polyester polyol, acrylic polyol, polybutadiene polyol, polyisoprene polyol, or the like.

[0046] Among the isocyanate-based curing agents (B), low-yellowing aliphatic and alicyclic isocyanates are preferred from the viewpoint of design, and the above adducts are preferred from the viewpoint of the film strength of the cured film. Suitable examples include an adduct of hexamethylene diisocyanate (HDI) and an adduct of 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI). Mixtures of these are also suitable.

[0047] From the viewpoint of storage stability of the thermosetting composition for forming a hard coat layer, a blocked isocyanate curing agent may be used as the isocyanate curing agent (B). As the blocked isocyanate curing agent, the above-mentioned unblocked isocyanate curing agent blocked with various blocking agents is used. As the blocking agent, one that dissociates at a relatively low temperature of about 80°C to 120°C is preferred. When an unblocked isocyanate curing agent is used as the isocyanate curing agent (B), a method is preferably used in which the (meth)acrylic copolymer (A) having a hydroxyl group and the isocyanate curing agent (B) are packaged separately and mixed immediately before use.

[0048] <Inorganic Oxide Fine Particles (C)> The inorganic oxide fine particles (C) have an average dispersed particle diameter D50 of 0.01 to 5 μm in the thermosetting composition. The average dispersed particle diameter D50 can be adjusted by selecting the type of inorganic oxide fine particles (C) and their average particle diameter D50. When the same inorganic oxide fine particles (C) are used, the average dispersed particle diameter D50 can be adjusted by adjusting the content of the inorganic oxide fine particles (C) in the thermosetting composition. Generally, as the content of the inorganic oxide fine particles (C) in the thermosetting composition increases, the average dispersed particle diameter D50 tends to increase due to particle aggregation. The average dispersed particle diameter D50 of the inorganic oxide fine particles (C) in the hard coat layer is substantially the same as the average dispersed particle diameter D50 of the inorganic oxide fine particles (C) in the thermosetting composition.

[0049] The use of inorganic oxide fine particles (C) having the above-described average dispersed particle diameter D50 in the hard coat layer contributes to the hard coat layer's film strength and reduces the contact area by creating an uneven surface, thereby contributing to its abrasion resistance. Furthermore, by using inorganic oxide fine particles (C) having an average dispersed particle diameter D50 of 0.01 to 5 μm in combination with a (meth)acrylic copolymer (A), a decorative film with excellent chemical resistance and abrasion resistance can be obtained, even when the film is thin. Furthermore, by using inorganic oxide fine particles (C) in combination with a (meth)acrylic copolymer (A), a decorative film with high stretchability and film strength can be obtained, even when the (meth)acrylic copolymer (A) has a relatively low molecular weight, such as an Mw of 50,000 to 200,000. The average dispersed particle diameter D50 of the inorganic oxide fine particles (C) in the thermosetting composition is preferably 0.01 to 0.2 μm or 1 to 3 μm. The average dispersed particle diameter D50 is a value measured using a Microtrac MT3300 EXII, and detailed measurement conditions are described in the Examples.

[0050] Specific examples of the inorganic oxide fine particles (C) include inorganic fine particles containing oxides, hydroxides, sulfates, carbonates, silicates, etc. of metals such as magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, and antimony. More specific examples include inorganic particles containing silica, silica gel, aluminum oxide, aluminum hydroxide, calcium hydroxide, calcium carbonate, magnesium oxide, magnesium hydroxide, aluminosilicate, talc, mica, glass fiber, glass powder, etc. The inorganic oxide fine particles (C) can be used alone or in combination of two or more.

[0051] As inorganic oxide fine particles (C) having an average dispersed particle diameter D50 of 0.01 to 0.2 μm in the thermosetting composition, aluminum oxide is preferred. The lower limit of the average dispersed particle diameter D50 of aluminum oxide is more preferably 0.02 μm. The upper limit of the average dispersed particle diameter D50 of aluminum oxide is more preferably 0.1 μm, even more preferably 0.09 μm, and still more preferably 0.08 μm.

[0052] Silica is preferred as the inorganic oxide fine particles (C) having an average dispersed particle diameter D50 of 1 to 3 μm in the thermosetting composition. The lower limit of the average dispersed particle diameter D50 of silica is more preferably 1.1 μm, and even more preferably 1.2 μm. The upper limit of the average dispersed particle diameter D50 of silica is more preferably 2.5 μm, even more preferably 2.2 μm, even more preferably 2.0 μm, and particularly preferably 1.8 μm. When using silica having an average dispersed particle diameter D50 of 1 to 3 μm in the thermosetting composition, it is preferable to use silicone oil in an amount of 1 part by mass or more and less than 5 parts by mass per 100 parts by mass of the (meth)acrylic copolymer (A). The method for measuring the average dispersed particle diameter D50 will be described in detail in the Examples.

[0053] When the average dispersed particle diameter D50 of the inorganic oxide fine particles (C) in the thermosetting composition is 0.01 to 0.2 μm, the inorganic oxide fine particles (C) are preferably contained in an amount of 1 to 30 parts by mass, more preferably 3 to 20 parts by mass, and even more preferably 5 to 10 parts by mass per 100 parts by mass of the (meth)acrylic copolymer (A). By containing 1 part by mass or more, the above-mentioned effect (the effect of imparting strength to the coating of the hard coat layer and improving scratch resistance) can be expected, and by containing 30 parts by mass or less, a durable hard coat layer that is excellent in formability and does not impair transparency can be formed.

[0054] When the average dispersed particle diameter D50 of the inorganic oxide fine particles (C) in the thermosetting composition is 1 to 3 μm, it is preferable to contain 0.1 to 10 parts by mass of inorganic oxide fine particles (C) per 100 parts by mass of (meth)acrylic copolymer (A), more preferably 0.1 to 3 parts by mass, and even more preferably 0.1 to 1.5 parts by mass. By using an amount of 0.1 parts by mass or more, the above-mentioned effect (the effect of imparting strength to the coating of the hard coat layer and improving scratch resistance) can be expected, and by using an amount of 10 parts by mass or less, a durable hard coat layer with excellent moldability and no impairment of transparency can be formed. Micro-sized inorganic oxide fine particles (C) significantly impair transparency, so the amount added is limited, but in the case of silica, a sufficient effect can be expected with an amount of 3 parts by mass or less.

[0055] <Silicone-based surface conditioner (D)> The thermosetting composition may contain a silicone-based surface conditioner (D). By adding the silicone-based surface conditioner (D), surface defects (poor leveling) can be suppressed when the thermosetting composition is applied in a thick film (more than 15 μm). This effect is particularly significant in the case of a thick film (more than 15 μm). In decorated molded products, the hard coat layer is stretched thinly by decorative molding, so when forming a hard coat layer from a thermosetting coating agent, it is applied so as to form a relatively thick film. In thick film formation, surface defects generally tend to occur more easily, so it is preferable to add a silicone-based surface conditioner (D) for the purpose of more effectively preventing surface defects.

[0056] The combined use of a silicone-based surface conditioner (D) and inorganic oxide fine particles (C) can more effectively improve scratch resistance. Various types of scratching materials are used in scratch resistance tests, including steel wool and metal dusters. By including inorganic oxide fine particles (C), the hard coat layer of the present disclosure can increase the strength or hardness of the coating surface and reduce the contact area of ​​the coating surface. As a result, the hard coat layer of the present disclosure can improve scratch resistance against steel wool, which is made of metal and has a rough surface. Furthermore, the hard coat layer of the present disclosure can reduce the dynamic friction force of the coating surface by further using a silicone-based surface conditioner (D). As a result, the hard coat layer of the present disclosure can effectively improve scratch resistance against a soft, flat cotton-made metal duster. Therefore, the combined use of inorganic oxide fine particles (C) and a silicone-based surface conditioner (D) can provide a hard coat layer with excellent scratch resistance against both steel wool and metal dusters.

[0057] Examples of the silicone-based surface conditioner (D) include polyether-modified silicone oil and silicone-containing acrylic copolymer.

[0058] Specific examples of polyether-modified silicone oils include BYK-300, BYK-302, BYK-306, BYK-307, BYK-320, BYK-325, BYK-330, BYK-331, BYK-333, BYK-337, BYK-342, BYK-345, BYK-347, BYK-348, BYK-349, BYK-375, BYK-377, BYK-378, BYK-3455, BYK-3500, BYK-3510, and BYK-3530 (all manufactured by BYK Japan); Silface SAG001, Silface SAG005 (manufactured by Nissin Chemical Industry Co., Ltd.); FZ-2191, FZ-2166, FZ-2154, FZ-2120, L-720, SH8700, L-7002, L-7001, SF8410, FZ-2123, SH8400, FZ-2164, FZ-77, FZ-2105, FZ-2208 (manufactured by Dow Corning Toray Co., Ltd.); SILWET L-8500, SILWET L-8610, SILWET L-8620, SILWET L-77, SILWET L-7280, SILWET L-7608, SILWET L-7001, SILWET L-7002, SILWET L-7087, SILWET L-7210, SILWET L-7220, SILWET L-7230, SILWET L-7500, SILWET L-7510, SILWET L-7602, SILWET L-7622, ​​SILWET L-7650, SILWET L-720 (all manufactured by Momentive Performance Materials Japan, Inc.). Specific examples of silicone-containing acrylic copolymers include the MODIPER FS series (FS700, FS710, FS720, FS730, FS770, etc.) (manufactured by NOF Corporation). The silicone-based surface conditioner (D) can be used alone or in combination of two or more types.

[0059] The silicone surface conditioner (D) is preferably contained in an amount of 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the (meth)acrylic copolymer (A). By keeping the content of the silicone surface conditioner (D) within this range, excellent scratch resistance is achieved.

[0060] <Thermosetting composition> The thermosetting composition contains a (meth)acrylic copolymer (A), an isocyanate-based curing agent (B), inorganic oxide fine particles (C), and a solvent. The type of solvent is not particularly limited, and known solvents can be used, but organic solvents are preferred from the viewpoint of the solubility of the (meth)acrylic copolymer (A) and the isocyanate-based curing agent (B). Examples of organic solvents include aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate, butyl acetate, and cellosolve acetate; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; and glycol ether solvents such as propylene glycol monomethyl ether (hereinafter referred to as PGM) and propylene glycol monomethyl ether acetate (hereinafter also referred to as PGMAC).

[0061] When a plastic having poor solvent resistance (e.g., polycarbonate) is used as the substrate layer, the solvent preferably contains at least one of alcohol, methyl isobutyl ketone (hereinafter also referred to as MIBK), PGMAC, and PGM. Note that alcohol can be used if the isocyanate-based curing agent (B) is a blocked isocyanate, and even if the isocyanate is an unblocked isocyanate, higher alcohols having poor reactivity with isocyanate groups can be used.

[0062] It is preferable to use a solvent having a boiling point of 50°C to 200°C. By making the boiling point 50°C or higher, the volatility of the solvent can be adjusted when applying the thermosetting composition, which is a curable composition, to a substrate film, making it easier to apply the composition with a uniform film thickness. Furthermore, by making the boiling point 200°C or lower, the drying properties of the solvent can be improved. Note that two or more solvents may be used.

[0063] In the present disclosure, the thermosetting composition may further contain an ultraviolet absorber or ultraviolet stabilizer for the purpose of imparting weather resistance to the hard coat layer formed. Examples of ultraviolet absorbers include organic ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, triazine-based ultraviolet absorbers, and indole-based ultraviolet absorbers, as well as inorganic ultraviolet absorbers such as zinc oxide. Preferred ultraviolet stabilizers are hindered amine compounds. The ultraviolet absorber and ultraviolet stabilizer may be added to the thermosetting composition as an additive, or a functional ultraviolet absorber or stabilizer may be reacted with an acrylic copolymer or another resin. These ultraviolet absorbers and stabilizers are preferably used in an amount of 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass, per 100 parts by mass of the solids content of the thermosetting composition excluding the ultraviolet absorber and ultraviolet stabilizer.

[0064] In the present disclosure, a polyol may be added to improve moldability. The polyol here refers to a compound other than the (meth)acrylic copolymer (A) that contains two or more hydroxyl groups capable of reacting with an isocyanate group. Examples include polyether polyols, polyester polyols, and polycarbonate polyols, and these can be used alone or in combination of two or more. In terms of the durability and moldability of the cured film, polyester polyols are particularly preferred.

[0065] Specific examples of the polyester polyol include ester compounds containing terminal hydroxyl groups obtained by esterifying at least one dicarboxylic acid with at least one polyol such as a polyhydric alcohol, a polyhydric phenol, or an alkoxy-modified product thereof. Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalic acid, p-oxybenzoic acid, p-(hydroxy)benzoic acid, 1,4-cyclohexanedicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid.

[0066] Examples of the polyhydric alcohol include 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 2-methyl-1,4-butanediol, 1,2-dimethyl-1,4-butanediol, 2-ethyl-1,4-butanediol, 1,5-pentanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 3-ethyl-1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,6-hexanediol, 3-methyl-1,6-hexanediol, 1,7-heptanediol, 2-methyl-1,7-heptanediol, and 3-methyl-1,7-heptanediol. Examples of the glycol esters include 4-methyl-1,7-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 2-ethyl-1,8-octanediol, 3-methyl-1,8-octanediol, 4-methyl-1,8-octanediol, 1,9-nonanediol, ethylene glycol, propylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol, cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, trimethylolpropane, 1,1,1-trimethylolpropane ethylene glycol, glycerin, erythritol, xylitol, sorbitol, and mannitol.

[0067] Examples of the polyhydric phenol include catechol, resorcinol, hydroquinone, hexylresorcinol, trihydroxybenzene, and dimethylolphenol.

[0068] Examples of commercially available polyester polyols having two or more hydroxyl groups include Kuraray Polyol P-510, P-1010, P-2010, P-3010, P-4010, P-5010, P-6010, P-2011, P-2012, P-520, P-1020, P-2020, P-1012, P-2012, P-530, P-2030, F-510, F-1010, F-2010, F-3010, and N-2010, all manufactured by Kuraray Co., Ltd.

[0069] Examples of the polyether polyol include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. Commercially available polyether polyols having two or more hydroxyl groups include PTG1000, PTG2000, and PTG3000 manufactured by Hodogaya Chemical Co., Ltd., PTMG650, PTMG850, PTMG1000, PTMG1300, PTMG1500, PTMG1800, PTMG2000, and PTMG3000 manufactured by Mitsubishi Chemical Corporation, and Sannix PP1000, Sannix PP2000, and Sannix PP3000 manufactured by Sanyo Chemical Industries, Ltd.

[0070] An example of the polycarbonate polyol is a polycarbonate diol represented by the following general formula: H—(O—R—OCO—) ｎ —ROH (R: alkyl chain, specifically, diethylene glycol, etc.; n is an integer, for example, 1 to 15.) Examples of commercially available polycarbonate polyols having two or more hydroxyl groups include Kuraray Polyol C-590, C-1090, C-2090, and C-3090 manufactured by Kuraray Co., Ltd. One type of polyol compound can be used, or two or more types can be used in combination.

[0071] The polyol preferably has a number average molecular weight (Mn) of 500 to 7,000, more preferably 800 to 6,000. Having an Mn of 500 or more provides sufficient flexibility, while having an Mn of 7,000 or less provides a high degree of crosslinking. The hydroxyl value of the polyol is preferably 10 mgKOH / g or more, more preferably 15 mgKOH / g or more. A hydroxyl value of 10 mgKOH / g or more provides a high degree of crosslinking, improving abrasion resistance, and a hydroxyl value of 15 mgKOH / g can further increase the degree of crosslinking, further improving abrasion resistance. Therefore, it is more preferable that the number average molecular weight is 800 to 6,000 and the hydroxyl value is 15 mgKOH / g or more.

[0072] The content of the polyol compound other than the (meth)acrylic copolymer (A) is not particularly limited as long as it does not impair the effects of the present disclosure, but the polyol is preferably 200 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 50 parts by mass or less, relative to 100 parts by mass of the (meth)acrylic copolymer (A) contained in the thermosetting composition for forming a hard coat layer. By making the polyol content 200 parts by mass or less relative to 100 parts by mass of the (meth)acrylic copolymer (A), it is possible to significantly improve moldability without significantly impairing durability.

[0073] In the present disclosure, the thermosetting composition for forming the hard coat layer may contain the (meth)acrylic copolymer (A) having hydroxyl groups, optional resins other than the aforementioned polyols, organic fine particles other than the inorganic oxide fine particles (C), organic solvents, etc., as long as the object of the present disclosure is not impaired. Examples of the (meth)acrylic copolymer (A) having hydroxyl groups and optional resins other than the aforementioned polyols include polyester resins, urethane resins, epoxy resins, thermoplastic acrylic resins, phenolic resins, and cellulose ester resins. These resins may or may not have crosslinkable functional groups. Preferably, they have crosslinkable functional groups.

[0074] Furthermore, if necessary, a curing accelerator may be added to the thermosetting composition for forming the hard coat layer, as long as it does not interfere with the effects of the present disclosure. The curing accelerator serves as a catalyst that promotes the urethane bond reaction between the hydroxyl groups in the (meth)acrylic copolymer (A) having hydroxyl groups and the isocyanate-based curing agent (B). Examples of the curing accelerator include tin compounds, metal salts, and bases. Specific examples include tin octylate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, tin chloride, iron octylate, cobalt octylate, zinc naphthenate, triethylamine, and triethylenediamine. These may be used alone or in combination.

[0075] If necessary, various additives such as fillers, thixotropy-imparting agents, antioxidants, antioxidants, antistatic agents, flame retardants, thermal conductivity improvers, plasticizers, anti-sagging agents, antifouling agents, preservatives, bactericides, antifoaming agents, leveling agents, curing agents, thickeners, pigment dispersants, and silane coupling agents may be further added to the thermosetting composition for forming the hard coat layer, within a range that does not impair the effects of the present disclosure.

[0076] The thermosetting composition for forming a hard coat layer is not limited, but can be obtained, for example, as follows. For example, a thermosetting composition for forming a hard coat layer can be obtained by weighing and blending predetermined amounts of a hydroxyl group-containing (meth)acrylic copolymer (A), an isocyanate-based curing agent (B), inorganic oxide fine particles (C), and a solvent (preferably an organic solvent) into a container and thoroughly stirring with a stirrer. The weight-average molecular weight (Mw) of the (meth)acrylic copolymer (A) is preferably 200,000 or less. If the Mw exceeds 1,000,000, the viscosity of the thermosetting composition increases, making it more likely to develop fish eyes or other problems resulting from gel formation during application. The solvent serves to adjust the viscosity and fluidity of the thermosetting composition. The solvent used during polymerization of the (meth)acrylic copolymer (A) may be used as is, or may be added during preparation of the thermosetting composition.

[0077] The thermosetting composition for forming a hard coat layer is preferably degassed before being applied to a substrate. If bubbles are present in the thermosetting composition, the bubbles may be mixed into the coating film being formed when the composition is applied to a substrate, and traces of broken bubbles may remain on the surface of the coating film after drying or curing. As a method for degassing, the composition may be stirred and then left to cool, or may be forcibly degassed using a vacuum degasser or the like.

[0078] The decorative film of the present disclosure has a hard coat layer, which is a cured product of the thermosetting composition, on a substrate layer. The decorative film may have a colored layer or a printed layer between the substrate and the hard coat layer.

[0079] <Hard Coat Layer> As described above, the hard coat layer is composed of a cured product of a thermosetting composition containing a (meth)acrylic copolymer (A), an isocyanate-based curing agent (B), and inorganic oxide fine particles (C). The hard coat layer also has a total light transmittance of 40% or more and a diffuse transmittance of 70% or less. Because of the high total light transmittance and low diffuse transmittance, when a colored layer or a printed layer is provided between the substrate layer and the main body of the object to be decorated, such as a molded body, or between the hard coat layer and the substrate layer, the colored layer or the printed layer can be more clearly seen through the hard coat layer. From the viewpoint of improving visibility, it is more preferable that the total light transmittance is 60% or more and the diffuse transmittance is 50% or less.

[0080] The hard coat layer in the present disclosure has a tensile strength of 15 to 100 N / mm under an atmosphere of 25°C and 50% relative humidity (hereinafter referred to as 50% RH). ２ The tensile strength is 15 N / mm ２ By setting the hard coat layer at a temperature of 100 N / mm or more, cracking and whitening of the hard coat layer during molding can be suppressed, and the hard coat layer can be formed to have a tensile strength of 100 N / mm or more. ２ When the tensile strength is not more than 20 N / mm, the decorative film can be excellent in conformity with the shape of the object to be decorated during molding, and molding defects such as the decorative film floating from the object to be decorated can be suppressed. ２ More preferably, 85 N / mm ２ is more preferred.

[0081] The hard coat layer may be formed on a release film, and after the hard coat layer is peeled off and isolated from the release film, it may be attached to a substrate layer or an object to be decorated via a laminating adhesive. The tensile strength of the hard coat layer alone obtained by this manufacturing method is 30 N / mm ２ When used as an acrylic cast film, the tensile strength is preferably 30 N / mm or more. ２ By satisfying the above conditions, the cured acrylic cast film can be rapidly and smoothly peeled off from the substrate film that has been subjected to a release treatment described below. On the other hand, this does not apply when the hard coat layer is formed by directly coating the coating liquid on the substrate layer.

[0082] The tensile strength in an atmosphere of 25°C and 50% RH in the present disclosure is a value measured by the method described in the Examples below. When an isolated hard coat layer (also called a cast film) is pulled by applying force and a stress-strain curve is drawn, initially a constant strain is shown relative to the stress, but when the stress reaches a certain point, the strain increases while the stress decreases. At this point, the film is said to have yielded. The stress at this point is called the "yield value" and is defined as the tensile strength in the present disclosure. The deformation up to the yield point is elastic deformation, and the shape returns to its original shape when the load is removed. However, after the yield point, the deformation becomes plastic, and the film does not return to its original shape by more than the amount of elastic deformation even when the load is removed.

[0083] The decorative film of the present disclosure preferably has an elongation of 150% or more at break in an atmosphere of 135°C and 50% RH. An elongation of 150% or more allows the film to easily conform to the mold during molding. There is no particular upper limit to the elongation, but from the viewpoint of achieving both moldability and durability, an elongation of 150 to 250% is preferred. The elongation in the present disclosure indicates the extent to which the sample has elongated relative to its original length; for example, 0% indicates no elongation at all, and 100% indicates that the sample has elongated to twice its original length (if the original length is 10 mm, it has been elongated by 10 mm, resulting in a total length of 20 mm).

[0084] Although there are no particular limitations on the thickness of the hard coat layer, it is preferably 3 to 200 μm from the viewpoint of formability and durability. In light of recent demands for thinner films, the upper limit of the film thickness is preferably 40 μm, more preferably 20 μm, even more preferably 15 μm, and even more preferably 12 μm or less. Depending on the application, the decorative film of the present disclosure has both chemical resistance and scratch resistance even when thinned, so that the hard coat layer can be applied to a thin thickness of 10 μm, 8 μm, 6 μm, 5 μm, 4 μm, etc.

[0085] <Substrate Layer> The substrate layer (sometimes referred to as "substrate") is not particularly limited as long as it is a film that serves as a support in the decorative film, and known films can be used. Examples include polyethylene film, polypropylene film, polyester film, polycarbonate film, polymethyl methacrylate film, polyamide film, polyimide film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, polystyrene film, polyacrylonitrile film, aluminum foil, and paper. These films can be used alone or in combination. For example, a PMMA / PC film in which polymethyl methacrylate (PMMA) is co-extruded onto polycarbonate (PC), or a film in which a polycarbonate film and a polyester film are laminated with an adhesive, can also be used. Note that polycarbonate film has good formability, polyester film has good solvent resistance (to organic solvents, sunscreen creams, etc.), and polymethyl methacrylate film has good hardness. Therefore, films or combinations thereof can be appropriately selected depending on the intended use. Furthermore, a release film obtained by applying a release agent such as silicone to such a film may be used as the substrate layer.

[0086] A peelable protective film can be further provided on the hard coat layer from the viewpoints of preventing blocking during production of the decorative film, preventing scratches, preventing scratches during molding, preventing mold marks, and preventing contamination of the decorated molded body after molding until it is used. Furthermore, when the decorative film is attached to the body to be decorated using an adhesive layer, a peelable protective film can also be further provided on the adhesive layer provided on the inside of the decorative film from the viewpoint of preventing blocking.

[0087] The protective film that can be used in the present disclosure is not particularly limited, and known plastic films and paper films can be appropriately selected and used. Examples of films that can be used as the protective film include, but are not limited to, polyethylene films, polypropylene films, polyester films, polycarbonate films, polymethyl methacrylate films, polyamide films, polyimide films, polyvinyl chloride films, polyvinylidene chloride films, polyvinyl alcohol films, polystyrene films, polyacrylonitrile films, aluminum foil, and paper. One or more types of films can be laminated together. Furthermore, the protective film may be formed by subjecting the plastic film to a release treatment or adhesive treatment.

[0088] Examples of methods for providing a protective film on the decorative film of the present disclosure include a method in which a coating liquid is applied to a substrate layer, dried, and a hard coat layer or adhesive layer is provided, and then the protective film is laminated, or a method in which a coating liquid is applied to a protective film, dried, and aged as necessary to provide a hard coat layer or adhesive layer, and then the substrate layer or decorative film is laminated. Note that when a hard coat layer is first provided on the protective film, the films may be laminated using an adhesive as necessary.

[0089] The thickness of the substrate layer is not particularly limited, but from the viewpoint of formability and durability, it is preferably 5 to 1,000 μm, more preferably 10 to 500 μm, and even more preferably 10 to 400 μm. The substrate layer may be a combination of multiple types of substrates with different thicknesses, in which case the total thickness of the combined substrate layers is preferably 5 to 1,000 μm.

[0090] <Article Comprising an Object to be Decorated and a Hard Coat Layer> The article of the present disclosure comprising an object to be decorated and a hard coat layer is an article in which the hard coat layer is a cured product of a thermosetting composition comprising a (meth)acrylic copolymer (A) having a hydroxyl group, an isocyanate-based curing agent (B), and inorganic oxide fine particles (C), wherein the (meth)acrylic copolymer (A) is a copolymer comprising a unit derived from a monomer having a hydroxyl group and a unit derived from another monomer, and satisfies the following conditions (I) to (VI): (I) The hard coat layer has a total light transmittance of 40% or more and a diffuse transmittance of 70% or less. (II) The hard coat layer has a tensile strength of 15 to 100 N / mm under an atmosphere of 25°C and a relative humidity of 50%. ２(III) The (meth)acrylic copolymer (A) has a hydroxyl value of 20 to 100 mgKOH / g, an acid value of 0 to 20 mgKOH / g, a glass transition temperature of 30 to 120°C, a weight-average molecular weight of 50,000 to 200,000, and a weight-average molecular weight / number-average molecular weight ratio of 2.0 to 10. (IV) The content of units derived from a monomer having one hydroxyl group in 100 mol% of units derived from a monomer having a hydroxyl group is 50 mol% or more. (V) 56 mol% or more of the hydroxyl groups in the (meth)acrylic copolymer (A) are primary hydroxyl groups. (VI) The inorganic oxide fine particles (C) have an average dispersed particle diameter D50 of 0.01 to 5 μm in the thermosetting composition. The article of the present disclosure may be molded or not. There are no particular limitations on the material of the object to be decorated, and known materials can be used. Examples of materials that can be used as the object to be decorated include wood, paper, metal, plastic, fiber-reinforced plastic, rubber, glass, minerals, and clay. These materials can be used alone or in combination of two or more. Examples of plastics include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyurethane, epoxy resin, acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene (AS) resin, poly(meth)acrylate, polycarbonate, polyamide, polyimide, polyphenylene ether, polyphenylene sulfide, polyester, and polytetrafluoroethylene, and these can be used alone or in combination of two or more. Examples of fiber-reinforced plastics include carbon fiber-reinforced plastic, glass fiber-reinforced plastic, aramid fiber-reinforced plastic, and polyethylene fiber-reinforced plastic, and these can be used alone or in combination of two or more. Examples of metals include hot-rolled steel, cold-rolled steel, galvanized steel, electrogalvanized steel, hot-dip galvanized steel, galvannealed hot-dip galvanized steel, zinc alloy-plated steel, copper-plated steel, zinc-nickel-plated steel, zinc-aluminum-plated steel, iron-galvanized steel, aluminum-plated steel, aluminum-galvanized steel, tin-plated steel, aluminum, stainless steel, copper, aluminum alloy, and electromagnetic steel, and these can be used alone or in combination of two or more. In addition, an anti-adhesive layer or the like may be provided on the surface of the metal.

[0091] The article of the present disclosure is manufactured by integrating a body to be decorated with a hard coat layer, and the hard coat layer is formed using the decorative film of the present disclosure. Methods for manufacturing articles using decorative films include a "lamination method," in which the substrate of the decorative film remains within the article, and a "transfer method," in which the substrate is not left behind. In the lamination method, the body to be decorated is decorated with the substrate of the decorative film positioned on the inside and the hard coat layer positioned on the outside. In contrast, in the transfer method, the body to be decorated is decorated with the substrate of the decorative film positioned on the outside and the hard coat layer positioned on the inside, and then the substrate is peeled off, resulting in the hard coat layer being positioned as the outermost layer. Therefore, the article of the present disclosure is not limited in any way by the presence or absence of a substrate derived from the decorative film. There are no particular limitations on the method for integrating the hard coat layer formed from the decorative film of the present disclosure with the body to be decorated, and integration can be achieved using known integration methods. Examples of integration methods include insert molding, in-mold molding, vacuum molding, pressure molding, TOM molding, and press molding.

[0092] The thermosetting composition can be applied by any known method for any of the above methods, including comma coating, gravure coating, reverse coating, roll coating, lip coating, and spray coating.

[0093] The thermosetting composition is preferably dried at 50 to 200°C, more preferably 70 to 120°C. Furthermore, it is preferable to divide the oven into several zones and set the oven temperature in a gradient from low to high, for example, the first zone at 50°C, the second zone at 70°C, and the third zone at 100°C. The residence time in the oven is usually about 1 to 10 minutes. A method may also be used in which several ovens with fixed temperatures are prepared and the composition is dried in each oven at each temperature for several minutes.

[0094] After drying, the reaction between the hydroxyl groups and the isocyanate groups is allowed to proceed (aging) for 1 to 10 days, usually in an environment of room temperature to about 100° C. Although a method of raising the oven temperature to about 150 to 200° C. and completing the reaction between the hydroxyl groups and the isocyanate groups while the film is passing through the oven can be selected, aging at a low temperature is preferred in terms of thermal damage to the base layer.

[0095] The solvent is dried in an oven, and the removed laminate may be aged in a sheet or rolled up. In either case, tack remains in the coating film before aging, and when it overlaps with the opposite side of the substrate layer, a blocking phenomenon may occur. To prevent such a blocking phenomenon, a separator for preventing blocking may be laminated on the coating film when stacking the sheets or when winding it into a roll. As the separator, a polyethylene terephthalate (PET) film that has been subjected to a release treatment, an unstretched propylene film, a polyethylene film, or the like is preferably used.

[0096] The decorative film of the present disclosure has various embodiments. Specific examples of these embodiments will be described with reference to the drawings. FIG. 1 shows a decorative film 101 having a two-layer structure of a hard coat layer 10 and a substrate layer 1. FIG. 2 shows a decorative film 102 having a laminate of the hard coat layer 10 and a substrate layer consisting of two layers, a first substrate layer 1a and a second substrate layer 1b. The first substrate layer 1a and the second substrate layer 1b can be formed, for example, by coextrusion. FIG. 3 shows a decorative film 103 having an adhesive layer 2 sandwiched between the hard coat layer 10 and the substrate layer 1. FIG. 4 shows a decorative film 104 having a hard coat layer 10 and the substrate layer 1, and a colored layer 3 on the side of the substrate layer 1 that does not face the hard coat layer 10. FIG. 5 shows a decorative film 105 having a laminate of the hard coat layer 10, the substrate layer 1, and the colored layer 3, with the colored layer 3 sandwiched between the hard coat layer 10 and the substrate layer 1. Fig. 6 shows a decorative film 106 having a hard coat layer 10, a substrate layer 1, an adhesive layer 2, and a colored layer 3, with the adhesive layer 2 sandwiched between the hard coat layer 10 and the substrate layer 1, and the colored layer 3 on the side of the substrate layer 1 that does not face the adhesive layer 2. Fig. 7 shows a decorative film 107 having a hard coat layer 10, a first substrate layer 1a, a second substrate layer 1b, a first adhesive layer 2a, and a second adhesive layer 2b, with the first adhesive layer 2a located between the hard coat layer 10 and the first substrate layer 1a and the second adhesive layer 2b located between the first substrate layer 1a and the second substrate layer 1b. Fig. 8 shows an embodiment having a hard coat layer 10, a substrate layer 1, a colored layer 3, and an adhesive layer 2, with the colored layer 3 located on the opposite side of the substrate layer 1 (the side that does not face the hard coat layer), and the hard coat layer 10 and the adhesive layer 2 located on the respective surfaces.

[0097] As a result of extensive research, the present inventors have found that by making 56 mol % or more of the hydroxyl groups in the (meth)acrylic copolymer (A) primary hydroxyl groups, a coating film having high scratch resistance and excellent chemical resistance can be obtained. This is believed to be because, by satisfying the above conditions, crosslinking can proceed more uniformly within the coating film.

[0098] The decorative film of the present disclosure uses a thermosetting coating film instead of a photocurable coating film, and therefore can be cured collectively regardless of the shape or size of the object to be decorated, resulting in high versatility and excellent productivity. Furthermore, by satisfying the above-mentioned (III) to (VI) as an acrylic copolymer and also satisfying the above-mentioned (I) to (II) and (VI), not only can excellent moldability be achieved, but also excellent design properties, chemical resistance, and scratch resistance can be obtained.

[0099] Decorative molded articles produced using the decorative film of the present disclosure are used as automotive interior parts such as metallic or piano black instrument panel decoration panels, shift gate panels, door trim, air conditioner operation panels, and car navigation systems, or as exterior parts such as front and rear emblems for automobiles, center ornaments for tire wheels, nameplates, etc. In addition to automotive interior and exterior parts, the decorative film can also be suitably used for exterior materials for home appliances, smart keys, smartphones, mobile phones, laptops, etc., as well as exterior materials for helmets and suitcases, protective sheets for protecting LCD screens for car navigation systems and LCD televisions, exterior materials for power storage devices, sporting goods such as tennis rackets and golf shafts, and building materials such as residential doors, partitions, and wall materials.

[0100] The present disclosure will be described in more detail below with reference to examples. The present disclosure is not limited to the following examples. In the examples, parts represent parts by mass, and % represents % by mass (excluding % of elongation).

[0101] Synthesis Example A-1 "Acrylic Copolymer (A-1) Solution" 53.85 parts of methyl ethyl ketone (MEK) was charged into a four-neck flask equipped with a condenser, a stirrer, a thermometer, and a nitrogen inlet tube, and the temperature was increased while stirring under a nitrogen atmosphere. When the temperature inside the flask reached 75°C, this temperature was maintained as the synthesis temperature. Thereafter, 13.50 parts of methyl methacrylate (MMA), 54.20 parts of n-butyl methacrylate (BMA), 18.00 parts of cyclohexyl methacrylate (CHMA), 0.50 parts of methacrylic acid (MAA), 12.80 parts of 4-hydroxybutyl acrylate (4HBA), 1.00 parts of 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate (FA-711MM), 0.11 parts of 2,2'-azobis(2,4-dimethylvaleronitrile) (V-65), and a monomer solution obtained by mixing 20.18 parts of MEK was added dropwise over 2 hours. One hour after the completion of the addition of the monomer, 0.021 parts of V-65 was added every hour to continue the reaction, and the reaction was continued until the amount of unreacted monomer in the solution was 1% or less. The reaction was terminated by cooling when the unreacted monomer content was 1% or less, and the solids content was adjusted to 30% using MEK, yielding a solution of acrylic copolymer (A-1). The acrylic copolymer (A-1) had a glass transition temperature of 30°C, an acid value of 3 mgKOH / g, a hydroxyl value of 50 mgKOH / g, a number average molecular weight of 70,000, a weight average molecular weight of 150,000, and a polydispersity index (Mw / Mn) of 2.14. The solids content, glass transition temperature (Tg), acid value, hydroxyl value, number average molecular weight (Mn), weight average molecular weight (Mw), and polydispersity index (Mw / Mn) were measured by the methods described below.

[0102] <<Measurement of Solid Content>> The mass of a lidded aluminum dish with a diameter of 55 mm and a depth of 15 mm was measured to four decimal places. Approximately 1.5 g of resin solution was placed in the aluminum dish, and the lid was immediately replaced, and the mass was measured quickly and accurately. With the lid removed, the dish was placed in an oven at 150°C and dried for 10 minutes. After cooling to room temperature, the mass of the aluminum dish and lid was measured, and the solid content was calculated using the following formula: Solid content (%) = (mass after drying - mass of aluminum dish) ÷ (mass before drying - mass of aluminum dish) x 100

[0103] Measurement of Glass Transition Temperature (Tg) The solvent in the acrylic copolymer solution was evaporated to prepare a sample with a 100% solids content. An aluminum pan containing approximately 10 mg of sample and another aluminum pan containing no sample were placed in a differential scanning calorimetry (DSC) instrument, and cooled to a temperature 50°C below the predicted glass transition temperature using liquid nitrogen in a nitrogen gas stream. The instrument was then heated at a rate of 10°C / min to a temperature 50°C above the predicted glass transition temperature, and a DSC curve was plotted. The extrapolated glass transition onset temperature (Tg) was determined from the intersection of a line extending the low-temperature baseline of the DSC curve (the portion of the DSC curve in the temperature range where no transition or reaction occurs in the test specimen) toward the high-temperature side and a tangent drawn at the point where the gradient of the stepwise change in the glass transition curve is maximum. This was designated as Tg.

[0104] <<Measurement of Acid Value (AV)>> Approximately 1 g of the acrylic copolymer solution was precisely weighed into a stoppered Erlenmeyer flask, and 50 mL of a toluene / ethanol (volume ratio: toluene / ethanol = 2 / 1) mixture was added and dissolved. Phenolphthalein test solution was added as an indicator, and the mixture was allowed to stand for 30 seconds. The solution was then titrated with 0.1 mol / L alcoholic potassium hydroxide solution until it turned a pale pink color. The acid value was calculated using the following formula. The acid value was the value for the acrylic copolymer in its dry state. Acid value (mg KOH / g) = (a × F × 56.1 × 0.1) / S, where S is the amount of acrylic copolymer solution collected × (solid content of acrylic copolymer solution / 100) (g), a is the amount of 0.1 mol / L alcoholic potassium hydroxide solution titrated (mL), and F is the titer of the 0.1 mol / L alcoholic potassium hydroxide solution.

[0105] Measurement of Hydroxyl Value (OHV): Approximately 1 g of the acrylic copolymer solution was precisely weighed into a stoppered Erlenmeyer flask and dissolved in 50 mL of a toluene / ethanol (volume ratio: toluene / ethanol = 2 / 1). Exactly 5 mL of an acetylating agent (a solution prepared by dissolving 25 g of acetic anhydride in pyridine to a volume of 100 mL) was then added, and the mixture was heated to 100°C and stirred for approximately 1 hour. Phenolphthalein test solution was added as an indicator and the mixture was stirred for 30 seconds. The solution was then titrated with 0.5 mol / L alcoholic potassium hydroxide solution until it turned a pale pink color. Separately, as a blank test, the acetylating agent was added to the toluene / ethanol mixture alone, and the resulting solution was heated to 100°C for 1 hour. This solution was then titrated with 0.5 mol / L alcoholic potassium hydroxide solution. The hydroxyl value was calculated using the following formula: The hydroxyl value was the value for the acrylic copolymer in its dry state. Hydroxyl value (mg KOH / g) = {(b - a) x F x 56.1 x 0.5} / S + D S: Amount of acrylic copolymer solution collected x (solid content of acrylic copolymer solution / 100) (g) a: Titration amount (mL) of 0.5 mol / L alcoholic potassium hydroxide solution b: Titration amount (mL) of 0.5 mol / L alcoholic potassium hydroxide solution in a blank experiment F: Titer of 0.5 mol / L alcoholic potassium hydroxide solution D: Acid value (mg KOH / g)

[0106] <<Measurement of number average molecular weight (Mn) and weight average molecular weight (Mw)>> Measurements were made using a Shodex GPC-101 system manufactured by Showa Denko K.K. Column: Shodex KF-805L + KF-803L + KF-802 Detector: Differential refractometer (RI) Column temperature: 40°C Eluent: Tetrahydrofuran (THF) Flow rate: 1.0 mL / min Sample concentration: 0.2% Calibration curve standard sample: TSK standard polystyrene The polydispersity was calculated from the obtained Mn and Mw using the following formula: Polydispersity = Mw / Mn

[0107] Synthesis Examples A-2 to A-18 "Acrylic Copolymer (A-2) to (A-18) Solutions" and Comparative Synthesis Examples A'-1 to A'-6 "Acrylic Copolymer (A'-1) to (A'-6) Solutions" Acrylic copolymer solutions were obtained by carrying out reactions in the same manner as in Synthesis Example A-1 using the compositions shown in Tables 1 to 3. "V-65 (aging)" in the tables indicates the number of parts of V-65 added per hour until the unreacted monomer content was 1% or less. The glass transition temperature, acid value, hydroxyl value, number average molecular weight, weight average molecular weight, and polydispersity are shown in Tables 1 to 3. The solids content was adjusted to 30% in all cases.

[0108] The symbols in the table are as follows: MMA: methyl methacrylate BMA: n-butyl methacrylate CHMA: cyclohexyl methacrylate IBX-MA: isobornyl methacrylate BA: n-butyl acrylate 2-EHMA: 2-ethylhexyl methacrylate MAA: methacrylic acid 4HBA: 4-hydroxybutyl acrylate HEMA: 2-hydroxyethyl methacrylate GLMA: glyceryl methacrylate (2,3-dihydroxypropyl methacrylate) 2HPMA: 2-hydroxypropyl methacrylate FA-711MM: 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, manufactured by Resonac Corporation V-65: 2,2'-azobis(2,4-dimethylvaleronitrile) In Tables 1 to 3, "content of monomer having one hydroxyl group" refers to the content of monomer (monomer-derived structural unit) having one hydroxyl group in the compound, relative to 100 mol% of monomer (monomer-derived structural unit) having a hydroxyl group that constitutes the (meth)acrylic copolymer (A). In addition, "proportion of primary OH groups" in the same tables refers to the proportion of primary hydroxyl groups among the hydroxyl groups in the (meth)acrylic copolymer (A).

[0109]

[0110]

[0111]

[0112] Example 1 (Production of Thermosetting Composition) To the acrylic copolymer solution obtained in Synthesis Example (A-1) containing 100 parts by mass (solid content) of the acrylic copolymer (A-1), 0.1 parts by mass (solid content) of BYK-300 (manufactured by BYK Corporation) and 1 part by mass (solid content) of BYK-UV3510 (manufactured by BYK Corporation) were added as the silicone surface conditioner (D), and the mixture was stirred for 15 minutes. Thereafter, as inorganic oxide fine particles (C-1), Optisol LAA-130C (manufactured by RANCO Corporation) diluted to 20% by mass with methyl ethyl ketone was added so that the solid content was 1 part by mass, and the mixture was stirred. Further, 12 parts by mass (solid content) of Duranate "P301-75E" (manufactured by Asahi Kasei Chemicals Corporation, polyisocyanate of hexamethylene diisocyanate) was added as an isocyanate-based curing agent (B-1), and PGM was further added so that the solid content became 30%, followed by stirring to obtain a thermosetting composition.

[0113] (Production of Decorative Film) Using an applicator, the thermosetting composition obtained above was applied to the surface of the PMMA-based resin layer of Iupilon Film DF02U (manufactured by Mitsubishi Gas Chemical Company, Inc., a two-layer sheet of PMMA-based resin layer / PC-based resin layer, total thickness 125 μm), and dried in an oven at 100°C for 2 minutes to volatilize the solvents. An applicator was selected so that the film thickness after drying would be 12 μm. The film was then left in a thermostatic chamber at 40°C for 4 days to allow the reaction between the acrylic copolymer and the polyisocyanate compound to proceed (aging), resulting in a decorative film in which a cured coating film was formed on the PMMA-based resin layer of the PMMA / PC film.

[0114] Examples 2 to 51, Comparative Examples 1 to 10 Thermosetting compositions and decorative films were produced in the same manner as in Example 1, except that the materials, blending amounts, and film thicknesses were changed as shown in Tables 6 to 10. Note that the inorganic oxide fine particles (C-1) were in the form of a dispersion and were therefore used without dilution.

[0115] As the inorganic oxide fine particles (C), those shown in Table 4 were used.

[0116] The silicone surface conditioner (D) used was one shown in Table 5.

[0117] <<Measurement of Average Dispersed Particle Diameter D50>> The dispersed particle diameter D50 of the inorganic oxide fine particles (C) in the thermosetting composition was measured using a particle size distribution measuring device using dynamic light scattering ("MT3300 EXII" manufactured by Microtrac-Bell Corporation). In the present disclosure, the thermosetting composition of each Example and Comparative Example in which inorganic oxide fine particles are dispersed (in the case of Synthesis Example A-1, an acrylic copolymer (A-1) solution adjusted to a solids content of 30%) was used, and the average value of three 60-second measurements was used at a concentration such that the loading index was in the range of 1.0±0.2.

[0118] <<Measurement of Total Light Transmittance and Diffuse Transmittance>> The thermosetting composition was applied to a release-treated PET film using an applicator to a thickness corresponding to each example, and then dried in a 100°C oven for 2 minutes to volatilize the solvents. The film was then left in a 40°C thermostatic chamber for 4 days to allow the reaction between the acrylic copolymer and the polyisocyanate compound to proceed (aging). The hard coat layer was isolated, and the total light transmittance and diffuse transmittance were measured using a haze meter SH-7000 manufactured by Nippon Denshoku Industries Co., Ltd. (wavelength range: 380 to 780 nm).

[0119] <<Measurement of Tensile Strength>> A thermosetting composition was applied to a release-treated PET film using an applicator so that the film would have a dry thickness of 100 μm, and the composition was dried in an oven at 100°C for 2 minutes to volatilize the solvents. The hard coat layer was then isolated and subjected to a tensile test using a Tensilon Universal Testing Machine RTE-1210 manufactured by TENSILON Co., Ltd. under the following conditions at 25°C and 50% RH to obtain a stress-strain curve. Tensile speed: 30 mm / min; Sample size: Width 20 mm x Thickness approx. 100 μm; Chuck distance: 23 mm

[0120] The decorative films obtained in the examples and comparative examples were evaluated for scratch resistance, elongation, sunscreen resistance, transparency, pencil hardness and weather resistance according to the methods described below.

[0121] <Evaluation of Scratch Resistance> [Steel Wool Resistance (SW Resistance)] A square pad of 1 cm2 equipped with #0000 steel wool was placed on the surface of the hard coat layer of each of the decorative films (hard coat layer / PMMA / PC film) prepared above, and was then moved back and forth 10 times with a load of 500 g, after which the appearance was visually evaluated and the number of scratches was counted. A level of 2 or higher was deemed acceptable. Evaluation criteria: 5: 0 scratches: particularly excellent; 4: 1 to less than 3 scratches: excellent; 3: 3 to less than 10 scratches: good; 2: 10 to less than 20 scratches: acceptable for practical use; 1: 20 or more scratches: target not achieved.

[0122] [Scratch resistance] A square pad of 1 cm2 equipped with a No. 3 scratch was placed on the surface of the hard coat layer of the decorative film prepared above, and was then moved back and forth 500 times with a load of 500 g, after which the appearance was visually evaluated and the number of scratches was counted. A level of 2 or higher was judged to be acceptable. 5: 0 scratches: particularly excellent 4: 1 to less than 3 scratches: excellent 3: 3 to less than 10 scratches: good 2: 10 to less than 20 scratches: acceptable for practical use 1: 20 or more scratches: target not achieved

[0123] <Evaluation of Elongation Rate> In the present disclosure, the elongation rate due to uniaxial stretching was measured as an alternative evaluation of formability. Using the decorative film prepared above, a tensile test was carried out in an atmosphere of 135°C and 50% RH using a Tensilon universal testing machine RTE-1210 manufactured by TENSILON. Tensile speed: 30 mm / min. Sample size: width 20 mm x thickness (125 μm substrate + hard coat layer (film thickness of each sample)). Distance between chucks: 23 mm. The elongation was measured as the value (X) mm at the moment when whitening, cracking or breakage occurred in the hard coat layer of the sample (decorative film). (Elongation) = (X) / 23 x 100. A score of 2 or higher was considered to be acceptable. The elongation of the substrate alone was approximately +300%. Evaluation criteria: 4: +250% or higher: Excellent; 3: +200% or higher but less than +250%: Excellent; 2: +150% or higher but less than +200%: Acceptable for practical use; 1: Less than +150%: Target not achieved.

[0124] <Evaluation of Chemical Resistance 1 (Sunscreen Resistance)> A 200 μm thick layer of sunscreen cream (Neutrogena Ultra Sheer DRY-TOUCH SUNSCREEN SPF45 (manufactured by Johnson & Johnson)) was applied to a 1 cm square area of ​​the hard coat layer of the decorative film prepared above, and left to stand at 55° C. for 4 hours. After leaving the film to stand, the sunscreen cream was rinsed off with water and the film was dried. The appearance of the decorative film on which the sunscreen cream had been applied was visually observed and evaluated according to the following criteria. A level of 2 or higher was rated as passing. Evaluation criteria 4: No defects in appearance such as traces or discoloration were observed on either the hard coat layer or the substrate layer. : Excellent 3: Slight traces of the applied area were visible when tilted. : Excellent 2: Slight traces of the applied area were visible even from the front. : Acceptable for use 1: Whitening of the applied area, surface roughness such as wrinkles, etc. was observed. : Target not achieved

[0125] <Evaluation of Chemical Resistance 2 (Resistance to Alkaline Detergents)> 0.2 mL of a 10% aqueous solution of sodium hydroxide was dropped onto the decorative film (5 cm square) prepared above, and heated in an oven at 55°C for 3 hours. After removal, the appearance was evaluated in the same manner as in the evaluation of Chemical Resistance 1. Evaluation criteria: 4: No defects in appearance such as traces or discoloration were observed on either the hard coat layer or the substrate layer. : Particularly excellent 3: Slight traces of the applied area were visible when tilted. : Excellent 2: Slight traces of the applied area were visible even from the front. : Usable 1: Whitening of the applied area, surface roughness such as wrinkles, etc. were observed. : Target not achieved

[0126] <Transparency Evaluation> The decorative film prepared above was cut into a piece of 3 cm x 3 cm, and the haze value was measured using a spectroscopic haze meter (SH7000, manufactured by Nippon Denshoku Industries Co., Ltd.). Transparency was evaluated according to the following evaluation criteria. A level of 2 or higher was considered acceptable. The haze value of the substrate alone was approximately 0.1. Evaluation criteria: 5: Haze value less than 0.4%: Excellent; 4: Haze value 0.4% or higher but less than 1.0%: Excellent; 3: Haze value 1.0% or higher but less than 1.5%: Good; 2: Haze value 1.5% or higher but less than 2.0%: Acceptable for practical use; 1: Haze value 2.0% or higher: Target not achieved

[0127] <Evaluation of Pencil Hardness> The pencil hardness was measured as the surface hardness of the hard coat layer of the decorative film prepared as described above. In accordance with JIS K5400 (1990), in a thermostatic chamber at an ambient temperature of 23°C, a cylindrical pencil tip was sharpened flat and the tip was held at a 45° angle with a load of 1 kg applied to the hard coat layer side of the decorative film cut to 80 mm x 60 mm, and a line was drawn on the surface to evaluate scratches. Five lines were drawn with the pencil, and the pencil hardness at which two or fewer of the five lines were scratched was used as the evaluation result. For example, five lines were drawn with an H pencil, and if two or fewer of the five lines were scratched, the pencil hardness was expressed as H. If three or more of the five lines were scratched, the test was repeated with an F pencil. If two or fewer lines were scratched, the pencil hardness was rated F. If three or more lines were scratched, the test was repeated with an HB pencil. A grade of H or higher was considered a pass.

[0128] Weather Resistance Test: A weather resistance test was carried out on the hard coat layer surface of the decorative film prepared above using the following accelerated weather resistance tester under the following conditions: Super Xenon Weather Meter SX75 manufactured by Suga Test Instruments Co., Ltd., xenon long life arc lamp 7.5 kW (ultraviolet region 300 to 400 nm), irradiation + rain 38°C, 95% RH, 160 W / m ２ , 12min irradiation 63℃, 50%RH, 160W / m ２ , 1 hour 48 minutes 100 times: 200 hours is one cycle, and a weather resistance test was performed for 10 cycles, for a total of 2000 hours. The gloss value of the hard coat layer surface before and after the test was measured using the gloss meter described below, and weather resistance was evaluated from the difference between the gloss value before the test and the gloss value after the test. Using a BYK-Gardner Micro Trigloss gloss meter, measurements were taken at three locations on the test piece at an incident / reflection angle of 60 degrees, and the average value was calculated. Gloss change (%) = (gloss value after test - gloss value before test) / gloss value before test x 10 3: The change in gloss between before and after the test was less than 10%. 2: The change in gloss after the test was 10% or more but less than 20%. 1: The change in gloss after the test was 20% or more but less than 30%.

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135] The decorative films of the present disclosure were confirmed to exhibit excellent transparency, stretchability, chemical resistance, abrasion resistance, and hardness, as shown in Examples 1 to 51 (Tables 6 to 10). On the other hand, when inorganic oxide fine particles (C) were not included, poor abrasion resistance was confirmed, as shown in Comparative Examples 1 and 2 (Table 11). When the average dispersed particle diameter of the inorganic oxide fine particles (C) in the thermosetting composition was greater than 5 μm, poor abrasion resistance and transparency were confirmed, as shown in Comparative Example 3. When the glass transition temperature of the (meth)acrylic copolymer (A) was less than 30°C, poor abrasion resistance, sunscreen resistance, and stretchability were confirmed, as shown in Comparative Example 9. When the weight-average molecular weight Mw of the (meth)acrylic copolymer (A) was greater than 200,000, poor stretchability was confirmed, as shown in Comparative Example 7. When the glass transition temperature Tg of the (meth)acrylic copolymer (A) was greater than 120°C, poor stretchability was confirmed, as shown in Comparative Example 6. When the weight average molecular weight Mw of the (meth)acrylic copolymer (A) is less than 50,000, it was confirmed that the chemical resistance (sunscreen resistance), scratch resistance, and hardness were poor, as shown in Comparative Example 8.

[0136] This application claims priority based on Japanese Patent Application No. 2023-222196, filed December 28, 2023, the disclosure of which is incorporated herein in its entirety by reference.

[0137] 101 to 108: Decorative film 10: Hard coat layer 1: Base material layer 1a: First base material layer 1b: Second base material layer 2: Adhesive layer 2a: First adhesive layer 2b: Second adhesive layer 3: Colored layer

Claims

1. A decorative film having a hard coat layer on a base material layer, wherein the hard coat layer is a cured product of a thermosetting composition containing a (meth)acrylic copolymer (A) having a hydroxyl group, an isocyanate curing agent (B), and inorganic oxide fine particles (C), the (meth)acrylic copolymer (A) is a copolymer composed of units derived from a monomer having a hydroxyl group and units derived from other monomers, and a decorative film satisfying the following conditions (I) to (VI). (I) The hard coat layer has a total light transmittance of 40% or more and a diffuse transmittance of 70% or less. (II) The tensile strength of the hard coat layer in an atmosphere of 25°C and a relative humidity of 50% is 15 to 100 N / mm ２ is. (III) The (meth)acrylic copolymer (A) has a hydroxyl value of 20 to 100 mgKOH / g, an acid value of 0 to 20 mgKOH / g, a glass transition temperature of 30 to 120°C, a weight average molecular weight of 50,000 to 200,000, and a weight average molecular weight / number average molecular weight of 2.0 to 10. (IV) In 100 mol% of the units derived from the monomer having a hydroxyl group in the (meth)acrylic copolymer (A), the content of the units derived from the monomer having one hydroxyl group is 50 mol% or more. (V) 56 mol% or more of the hydroxyl groups in the (meth)acrylic copolymer (A) are primary hydroxyl groups. (VI) The average dispersed particle diameter D50 of the inorganic oxide fine particles (C) in the thermosetting composition is 0.01 to 5 μm.

2. The decorative film according to claim 1, wherein the thermosetting composition further contains a silicone-based surface conditioner (D).

3. The decorative film according to claim 1, wherein the average dispersed particle diameter D50 of the inorganic oxide fine particles (C) in the thermosetting composition is 0.01 to 0.2 μm or 1 to 3 μm.

4. The decorative film according to claim 1, wherein the thickness of the hard coat layer is 4 to 15 μm.

5. An article comprising a substrate and a hard coat layer, wherein the hard coat layer is a cured product of a thermosetting composition containing a (meth)acrylic copolymer (A) having a hydroxyl group, an isocyanate curing agent (B), and inorganic oxide fine particles (C), and the (meth)acrylic copolymer (A) is a copolymer composed of units derived from a monomer having a hydroxyl group and units derived from other monomers, and the article satisfies the following conditions (I) to (VI). (I) The hard coat layer has a total light transmittance of 40% or more and a diffuse transmittance of 70% or less. (II) The tensile strength of the hard coat layer in an atmosphere of 25 °C and 50% relative humidity is 15 to 100 N / mm ２ . (III) The (meth)acrylic copolymer (A) has a hydroxyl value of 20 to 100 mgKOH / g, an acid value of 0 to 20 mgKOH / g, a glass transition temperature of 30 to 120 °C, a weight average molecular weight of 50,000 to 200,000, and a weight average molecular weight / number average molecular weight of 2.0 to 10. (IV) In 100 mol% of the units derived from the monomer having a hydroxyl group in the (meth)acrylic copolymer (A), the content of the units derived from the monomer having one hydroxyl group is 50 mol% or more. (V) 56 mol% or more of the hydroxyl groups in the (meth)acrylic copolymer (A) are primary hydroxyl groups. (VI) The average dispersed particle diameter D50 of the inorganic oxide fine particles (C) in the thermosetting composition is 0.01 to 5 μm.

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