Laminate and protective film

Abstract

To provide a laminate that exhibits superior humidity-heat resistance and weather resistance, a protective film for a substrate having a lightfastness rating of at least III in accordance with ASTM D4303, and a laminate obtained using the protective film.SOLUTION: A laminate comprises an acrylic resin layer comprising at least a layer composed of an acrylic resin composition (A) with a transmittance of below 1% at 380 nm wavelength, and a substrate layer with a lightfastness rating of at least III in accordance with ASTM D4303.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a laminate and a protective film. [Background technology]

[0002] Acrylic resin films are excellent in transparency and weather resistance, and are therefore preferably used as overlay films that are attached to various molded articles such as outdoor building materials to protect the surfaces. Furthermore, the substrate of a molded product is often given various colors and patterns to enhance its design, and there is a demand for an overlay film that does not impair the design regardless of the color or pattern.

[0003] For example, Patent Document 1 discloses an overlay film for a melamine decorative board known as an outdoor building material. Specifically, it discloses an acrylic resin laminate film that has excellent adhesion to a melamine substrate and is excellent in water resistance and appearance. On the other hand, Patent Document 2 discloses a light-shielding film containing a triazine-based ultraviolet absorber that can efficiently block ultraviolet rays in the long wavelength region (380 nm to 400 nm). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2014 / 192708 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-67811 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the films of Patent Documents 1 and 2 are laminated with a melamine decorative board having a lightfastness rating of III or higher according to ASTM D4303, the weather resistance of the resulting laminate may be insufficient.In addition, there is a risk that the appearance of the laminate may be impaired due to bleeding out of additives in a humid and hot environment.

[0006] Therefore, an object of the present invention is to provide a laminate having excellent moist heat resistance and weather resistance, a protective film for a substrate having a lightfastness rating of III or higher according to ASTM D4303, and a laminate using the same. [Means for solving the problem]

[0007] As a result of intensive research, the present inventors have found that the above object can be achieved by combining a resin layer having specific physical properties with a substrate, and have thus completed the present invention. That is, the present invention relates to the following [1] to

[21] . [1] A laminate comprising an acrylic resin layer including at least a layer made of an acrylic resin composition (A) having a transmittance of less than 1% at a wavelength of 380 nm, and a substrate layer having a lightfastness rating of III or higher according to ASTM D4303. [2] The laminate according to [1], wherein the acrylic resin layer has a transmittance of less than 1% at a wavelength of 380 nm after 480 hours of metal weather exposure testing. [3] The laminate according to [1] or [2], wherein the acrylic resin composition (A) contains a core-shell rubber (A-1). [4] The laminate according to any one of [1] to [3], wherein the acrylic resin composition (A) has an acetone insoluble content of 65% or less. [5] The laminate according to any one of [1] to [4], wherein the acrylic resin composition (A) has a storage modulus at 100° C. of 20 MPa or more. [6] The laminate according to any one of [1] to [5], wherein the acrylic resin composition (A) contains an ultraviolet absorber, and the molecular weight of the ultraviolet absorber is 400 or more. [7] The laminate according to [6], wherein the ultraviolet absorber is a triazine-type ultraviolet absorber and / or a benzotriazole-type ultraviolet absorber. [8] The laminate according to [6] or [7], wherein the ultraviolet absorber has a 10% weight loss temperature of 300°C or higher. [9] The laminate according to any one of [6] to [8], wherein the content of the ultraviolet absorber in 100 parts by mass of the acrylic resin composition (A) is 0.01 to 10 parts by mass.

[10] The laminate according to any one of [1] to [9], wherein the acrylic resin composition (A) contains a colorant, and the colorant has a Lightfastness rating of less than III according to ASTM D4303.

[11] The laminate according to any one of [1] to

[10] , wherein the acrylic resin layer has a YI of less than 10.

[12] The laminate according to any one of [1] to

[11] , wherein the substrate layer (also referred to as substrate) contains an azo pigment other than a condensed azo pigment.

[13] The laminate according to any one of [1] to

[11] , wherein the substrate layer (also referred to as substrate) is a melamine substrate.

[14] A protective film for a substrate, comprising at least a layer made of an acrylic resin composition (A), and having a lightfastness rating of III or higher according to ASTM D4303, which has a transmittance at a wavelength of 380 nm of less than 1%.

[15] The protective film for a substrate according to

[14] , wherein the acrylic resin composition (A) contains a core-shell rubber (A-1).

[16] The protective film for a substrate according to

[14] or

[15] , wherein the acrylic resin composition (A) contains an ultraviolet absorber, and the molecular weight of the ultraviolet absorber is 400 or more.

[17] The protective film for a substrate according to

[16] , wherein the ultraviolet absorber is a triazine-type ultraviolet absorber and / or a benzotriazole-type ultraviolet absorber.

[18] The protective film for a substrate according to

[16] or

[17] , wherein the ultraviolet absorber has a 10% weight loss temperature of 300°C or higher.

[19] The protective film for a substrate according to any one of

[16] to

[18] , wherein the content of the ultraviolet absorber in 100 parts by mass of the acrylic resin composition (A) is 0.01 to 10 parts by mass.

[20] The protective film for a substrate according to any one of

[14] to

[19] , wherein the protective film for a substrate is a laminated film comprising a resin layer (I) made of the acrylic resin composition (A) and a resin layer (II) made of an acrylic resin composition (B) containing a reactive group-containing acrylic resin (B-1).

[21] A laminate comprising the protective film for a substrate according to any one of

[14] to

[20] and the substrate. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a laminate with a substrate having excellent moist heat resistance and weather resistance and a Lightfastness rating of III or higher according to ASTM D4303, a protective film for a substrate having a Lightfastness rating of III or higher according to ASTM D4303, and a laminate using the same. DETAILED DESCRIPTION OF THE INVENTION

[0009] One embodiment of the present invention will be described in detail below, but the present invention is not limited to the following embodiments as long as it does not deviate from the purpose. In this specification, the range "to" includes the upper and lower limits. Furthermore, for each preferred range, the upper and lower limits can be used in any combination.

[0010] One aspect of the present invention includes a laminate comprising an acrylic resin layer including at least a layer (hereinafter also referred to as resin layer (I)) made of an acrylic resin composition (A) having a transmittance at a wavelength of 380 nm of less than 1%, and a substrate layer (hereinafter also referred to as substrate or melamine substrate) having a lightfastness rating of III or higher according to ASTM D4303. Also included in one aspect of the present invention are protective films for substrates having a lightfastness rating of III or higher according to ASTM D4303, and laminates using the same.

[0011] [Resin layer (I)] The resin layer (I) is a layer made of an acrylic resin composition (A) described below. The storage modulus of the acrylic resin composition (A) at 100°C is preferably 20 MPa or more, more preferably 20 to 1,000 MPa, and even more preferably 50 to 900 MPa. When the storage modulus of the acrylic resin composition (A) at 100°C is 20 MPa or more, the heat resistance and surface hardness of the melamine decorative board are good. When the storage modulus of the acrylic resin composition (A) at 100°C is 1,000 MPa or less, bleeding out of the ultraviolet absorber is suppressed, and the transferability of the embossed pattern when transferred by hot pressing is good, allowing the production of a melamine decorative board with good appearance. Melamine decorative boards are usually made by hot pressing at a temperature of 140 to 160°C, but when many large-area laminates are stacked and pressed at the same time, the temperature can become uneven in some areas, resulting in low-temperature areas of around 100°C. Even in such cases, a melamine decorative board with a good appearance can be obtained as long as the storage modulus at 100°C is 1000 MPa or less.

[0012] [Acrylic resin composition (A)] The acrylic resin composition (A) of the present invention preferably contains a core-shell rubber (A-1) from the viewpoints of film productivity and handling. For example, the acrylic resin composition (A) may contain a thermoplastic polymer (A-2) and an additive (A-3) in addition to the core-shell rubber (A-1). In particular, the acrylic resin composition (A) preferably contains 5.5 to 95 mass% of the core-shell rubber (A-1) and 5 to 94.5 mass% of the thermoplastic polymer (A-2) relative to 100 mass% of the core-shell rubber (A-1) and the thermoplastic polymer (A-2), and further contains 0.01 to 20 mass parts of the additive (A-3) relative to 100 parts by mass of the core-shell rubber (A-1) and the thermoplastic polymer (A-2). When the content of the core-shell rubber (A-1) is 5.5% by mass or more, the resin layer (I) is provided with greater toughness, the film is less likely to break during production, and productivity is improved. Also, the film is easy to handle when in use. When the content of the thermoplastic polymer (A-2) is 5% by mass or more, the surface hardness of the resin layer (I) is improved.

[0013] The acrylic resin composition (A) more preferably contains 10 to 90 mass% of the core-shell rubber (A-1) and 10 to 90 mass% of the thermoplastic polymer (A-2), and even more preferably contains 15 to 85 mass% of the core-shell rubber (A-1) and 15 to 85 mass% of the thermoplastic polymer (A-2), relative to 100 mass% of the total of the core-shell rubber (A-1) and the thermoplastic polymer (A-2). The acrylic resin composition (A) preferably contains 0.1 to 10 parts by mass, and more preferably 1 to 8 parts by mass, of the additive (A-3) relative to 100 parts by mass of the core-shell rubber (A-1) and the thermoplastic polymer (A-2) combined.

[0014] [Core-shell rubber (A-1)] The core-shell rubber (A-1) may be a particle having a multilayer structure, and is preferably a rubber particle having a multilayer structure of two or more layers, having a layer containing a hard polymer (a-2) as an outer layer on a layer containing an elastic copolymer (a-1) as an inner layer. Specific examples of the core-shell rubber (A-1) include acrylic rubber, silicone rubber, butadiene rubber, etc., and from the viewpoints of transparency and weather resistance, acrylic rubber is preferred. Examples of the acrylic rubber include the same as the core-shell rubber (B-2) described later.

[0015] The particle size of the core-shell rubber (A-1) is preferably 100 to 400 nm, more preferably 150 to 350 nm, and even more preferably 200 to 300 nm. When the particle size of the core-shell rubber (A-1) is 100 nm or more, the amount of rubber added per unit area can be reduced, resulting in better surface hardness. When the particle size of the core-shell rubber (A-1) is 400 nm or less, the film has excellent transparency.

[0016] [Thermoplastic polymer (A-2)] The thermoplastic polymer (A-2) is a thermoplastic polymer other than the core-shell rubber (A-1), and is preferably a polymer obtained by polymerizing a monomer containing an alkyl methacrylate ester as a main component. Examples of the thermoplastic polymer (A-2) include the thermoplastic polymer (B-3) and polymer-based processing aids described below.

[0017] [Additive (A-3)] The additive (A-3) is a compound other than the core-shell rubber (A-1) and the thermoplastic polymer (A-2), and contains an ultraviolet absorber as an essential component, and optionally contains an antiblocking agent, a stabilizer, a lubricant, a plasticizer, a foaming agent, a filler, and a colorant.

[0018] For example, an ultraviolet absorber is included as additive (A-3) to provide weather resistance to protect the substrate. In the present application, it is necessary to protect the melamine decorative laminate, which deteriorates in the long wavelength region of ultraviolet light (380 nm to 400 nm) to visible light (400 nm to 700 nm). Therefore, an ultraviolet absorber (also called a blue light cut agent) having absorption characteristics in the range of 380 nm to 500 nm is preferred. The absorbance at 400 nm measured by the method described below is preferably 0.05 or more, more preferably 0.06 or more.

[0019] In terms of maintaining ultraviolet shielding ability for a long period of time, benzotriazole-type ultraviolet absorbers and / or triazine-type ultraviolet absorbers are preferred, and triazine-type ultraviolet absorbers are more preferred.

[0020] The molecular weight of the ultraviolet absorber is preferably 300 or more, more preferably 400 or more, and even more preferably 500 or more. If the molecular weight is 300 or more, the ultraviolet absorber is less likely to volatilize during film formation, and the light-blocking performance is less likely to decrease and mold contamination is less likely to occur. Furthermore, bleed-out of the ultraviolet absorber after molding is less. On the other hand, the upper limit of the ultraviolet absorber is not particularly limited, but from the viewpoint of compatibility with the core-shell rubber (A-1) or the thermoplastic polymer (A-2), for example, it is 300,000 or less, more preferably 200,000 or less, more preferably 100,000 or less, more preferably 5,000 or less, more preferably 3,000 or less, and most preferably 1,000 or less.

[0021] The 10% weight loss temperature of the ultraviolet absorber is preferably 250°C or higher, more preferably 300°C or higher, and even more preferably 350°C or higher. If the 10% weight loss temperature is 250°C or higher, the ultraviolet absorber is less likely to decompose during film formation, and the light-blocking performance is less likely to decrease. On the other hand, the upper limit of the 10% weight loss temperature is preferably 1000°C or lower, more preferably 950°C or lower, more preferably 900°C or lower, more preferably 800°C or lower, more preferably 700°C or lower, more preferably 600°C or lower, and most preferably 500°C or lower.

[0022] Examples of benzotriazole-type ultraviolet absorbers that satisfy the above requirements include Phenol, 2-(5-chloro-2H-benzotriazol-2-yl)-6-(1,1-dimethylethyl)-4-methyl; "Tinuvin 326" (trade name, manufactured by BASF). Commercially available triazine-based ultraviolet absorbers that satisfy the above requirements include, for example, 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-1,3,5-triazine, "ADEKA STAB LAF70" (trade name, manufactured by ADEKA Corporation). These may be used alone or in combination of two or more, and may also be used in combination with an ultraviolet absorber having absorption characteristics at less than 380 nm.

[0023] Examples of ultraviolet absorbers having absorption characteristics at less than 380 nm include 2,2'-Methylenebis[6-(2H-benzotoriazol-2-yl)-4-(1,3,3,3-tetramethylbutyl)phenol]; "ADK STAB LA31RG" (trade name, manufactured by ADEKA CORPORATION), 2-(4,6-Diphenyl-1,3,5-triazin-2-yl)-5-(hexyloxy)phenol; "TINUVIN 1577" (trade name, manufactured by BASF), and 2-[4,6-Diphenylyl]-1,3,5-triazine-2-yl]-5-(2-ethylhexyloxy)phenol; "TINUVIN 1600" (trade name, manufactured by BASF).

[0024] The content of the ultraviolet absorber is preferably 0.01 to 10 parts by mass per 100 parts by mass of the total of the core-shell rubber (A-1) and the thermoplastic polymer (A-2) from the viewpoint of weather resistance, more preferably 0.5 to 5 parts by mass from the viewpoints of light-blocking performance, prevention of mold contamination during molding, and bleed-out resistance, and even more preferably 1 to 3 parts by mass from the viewpoint of coloring of the film.

[0025] Furthermore, the content of the ultraviolet absorber in 100 parts by mass of the acrylic resin composition (A) is preferably 0.01 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and even more preferably 1 to 3 parts by mass, from the viewpoints of suppressing YI of the film and making the transmittance of the film at a wavelength of 380 nm less than 1%.

[0026] In addition, from the viewpoint of imparting weather resistance to protect the substrate and making fading of the substrate less noticeable, the additive (A-3) preferably contains a colorant. As the colorant, a pigment or dye having a Lightfastness rating of less than III according to ASTM D4303 is more preferred, and a colorant having absorption characteristics in the range of 380 nm to 500 nm is even more preferred. Examples thereof include pigments or dyes other than low-molecular-weight azo pigments or dyes. More specific examples include condensed azo pigments or dyes, anthraquinone pigments or dyes, and perylene pigments or dyes. Specifically, the condensed azo pigments or dyes are disazo-type azo pigments or dyes. Commercially available colorants include, for example, MBR D-05 (trade name) manufactured by Dainichi Seika Color & Chemicals Mfg. Co., Ltd., containing an anthraquinone yellow dye (CI Solvent Yellow 163) as a yellow dye, MBR421 (trade name) manufactured by Dainichi Seika Color & Chemicals Mfg. Co., Ltd., containing an anthraquinone yellow pigment (CI Pigment Yellow 199), MBR151 (trade name) manufactured by Dainichi Seika Color & Chemicals Mfg. Co., Ltd., containing an anthraquinone red pigment (CI Pigment Red 177), MBR155 (trade name) manufactured by Dainichi Seika Color & Chemicals Mfg. Co., Ltd., containing a perylene red pigment (CI Pigment Red 149), MBR155 (trade name) manufactured by Dainichi Seika Color & Chemicals Mfg. Co., Ltd., containing an anthraquinone red pigment (CI Pigment Red 177), MBR165: "Dymic Color MBR165" (trade name) manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd., and MBR D-09 containing an anthraquinone-based red dye (CI Disperse Red 22) as a red dye: "Dymic Color MBR D-09" (trade name) manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.

[0027] The content of the colorant is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the core-shell rubber (A-1) and the thermoplastic polymer (A-2) in total, from the viewpoint of making the transmittance of the film at a wavelength of 380 nm less than 1%, and more preferably 1 to 6 parts by mass, from the viewpoint of coloring the film.

[0028] In order to further improve weather resistance, it is preferable to use a radical scavenger such as a hindered amine light stabilizer in combination with the ultraviolet absorber. Commercially available radical scavengers include, for example, "ADK STAB LA-57," "ADK STAB LA-62," "ADK STAB LA-67," "ADK STAB LA-63," and "ADK STAB LA-68" (all trade names, manufactured by ADEKA CORPORATION); "SANOL LS-770," "SANOL LS-765," "SANOL LS-292," "SANOL LS-2626," "SANOL LS-1114," and "SANOL LS-744" (all trade names, manufactured by Sankyo Lifetech Co., Ltd.). These may be used alone or in combination of two or more.

[0029] From the viewpoint of bleed-out resistance, the amount of the radical scavenger added is preferably 0 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, per 100 parts by mass of the total of the core-shell rubber (A-1) and the thermoplastic polymer (A-2).

[0030] In order to provide an anti-blocking effect, the additive (A-3) preferably contains an anti-blocking agent. An example of a commercially available antiblocking agent is "AEROSIL R976" (manufactured by Nippon Aerosil Co., Ltd.).

[0031] The amount of antiblocking agent added is preferably 0.01 to 2% by mass, more preferably 0.05 to 1.5% by mass, and even more preferably 0.1 to 1.0% by mass, relative to 100% by mass of the acrylic resin composition (A). When the content of the antiblocking agent is 0.01% by mass or more, blocking between films can be prevented when storing the film in sheet form for use in melamine decorative boards, resulting in excellent handleability. When the content of the antiblocking agent is 2% by mass or less, the decrease in transparency of the resulting film can be suppressed, and the occurrence of fisheyes can be reduced.

[0032] Furthermore, in order to prevent sticking to the press plate when the melamine decorative board is produced by pressing, the additive (A-3) preferably contains a release agent. Examples of the release agent include silicone compounds, fluorine compounds, alkyl alcohols, and alkyl carboxylic acids. Among these, alkyl carboxylic acids are preferred from the standpoints of availability and economy. Examples of alkylcarboxylic acids include linoleic acid, vaccenic acid, stearic acid, oleic acid, margaric acid, palmitoleic acid, palmitic acid, and pentadecylic acid. These may be used alone or in combination of two or more.

[0033] The amount of the release agent added is preferably 0.01 to 2 parts by mass, more preferably 0.1 to 0.5 parts by mass, per 100 parts by mass of the core-shell rubber (A-1) and the thermoplastic polymer (A-2) in total, from the viewpoint of preventing sticking to the press plate.

[0034] The acetone insoluble content of the acrylic resin composition (A) is preferably 65% ​​or less, more preferably 60% or less, and even more preferably 55% or less. When the acetone insoluble content is 65% or less, the surface hardness is good. Furthermore, the acetone insoluble content is preferably 1% or more, more preferably 3% or more, even more preferably 5% or more, and most preferably 10% or more. When the acetone insoluble content is 1% or more, the film toughness is good. The acetone insoluble content can be set within a desired range by, for example, adjusting the amount of core-shell rubber (A-1) added to the resin layer (I). The value of the acetone insoluble content can be calculated by the method described in the Examples below.

[0035] [Resin layer (II)] When the film of the present invention is a laminated film, it preferably contains a resin layer (II) in contact with the resin layer (I). From the viewpoint of adhesion to the melamine decorative board, as long as the resin layer (II) is disposed as the outer layer, it may be a two-layer film of two kinds of resin layers (I) / resin layer (II), or a two-layer film of two kinds of resin layers (II) / resin layer (I) / resin layer (II).

[0036] The resin layer (II) is a layer made of an acrylic resin composition (B), and preferably contains a reactive group-containing resin (B-1) as the acrylic resin. The reactive group-containing resin (B-1) contains a monomer unit having a reactive group. The acrylic resin in the resin layer (II) is preferably the reactive group-containing resin (B-1). The resin layer (II) may contain, in addition to the reactive group-containing resin (B-1), a core-shell rubber (B-2), and / or a thermoplastic polymer (B-3), and / or an additive (B-4), and preferably contains the core-shell rubber (B-2), the thermoplastic polymer (B-3), and / or the additive (B-4), and more preferably contains the core-shell rubber (B-2), the thermoplastic polymer (B-3), and the additive (B-4). From the viewpoint of transparency, the resin layer (II) preferably contains silica particles in an amount of less than 2 parts by mass, more preferably less than 1.5 parts by mass, and even more preferably less than 1.0 part by mass, based on the total mass of the resin layer (II). The content of silica particles may be 0 part by mass.

[0037] The resin layer (II) may contain, in addition to the reactive group-containing resin (B-1), a core-shell rubber (B-2), a thermoplastic polymer (B-3), and an additive (B-4). The resin layer (II) may contain 10 to 100 mass% of the reactive group-containing resin (B-1) and 0 to 90 mass% of the core-shell rubber (B-2), with the total of the reactive group-containing resin (B-1) and the core-shell rubber (B-2) being 100 mass% ("containing 0 mass% of the core-shell rubber (B-2)" means that the core-shell rubber (B-2) is not contained). The reactive group-containing resin (B-1) and the core-shell rubber (B-2) in the above ranges are advantageous in terms of adhesion and crack prevention. Furthermore, the composition may contain 0 to 50 parts by mass of a thermoplastic polymer (B-3) (containing 0 parts by mass of the thermoplastic polymer (B-3) means that the thermoplastic polymer (B-3) is not contained), and 0 to 50 parts by mass of an additive (B-4) (containing 0 parts by mass of the additive (B-4) means that the additive (B-4) is not contained), relative to a total of 100 parts by mass of the reactive group-containing resin (B-1) and the core-shell rubber (B-2) (which may not include the core-shell rubber (B-2)).

[0038] From the viewpoints of adhesion, film handling properties, scratch resistance, and prevention of cracks during molding, the resin layer (II) preferably contains 10 to 90 mass% of the reactive group-containing resin (B-1) and 10 to 90 mass% of the core-shell rubber (B-2), more preferably 15 to 90 mass% of the reactive group-containing resin (B-1) and 10 to 85 mass% of the core-shell rubber (B-2), and even more preferably 20 to 90 mass% of the reactive group-containing resin (B-1) and 10 to 80 mass% of the core-shell rubber (B-2), relative to 100 mass% of the total of the reactive group-containing resin (B-1) and the core-shell rubber (B-2). Furthermore, it is preferable that the thermoplastic polymer (B-3) be contained in an amount of 0.1 to 10 parts by mass and the additive (B-4) be contained in an amount of 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass of the thermoplastic polymer (B-3) and 1 to 5 parts by mass of the additive (B-4), and even more preferably 1.5 to 4 parts by mass of the thermoplastic polymer (B-3) and 2 to 4 parts by mass of the additive (B-4), relative to a total of 100 parts by mass of the reactive group-containing resin (B-1) and the core-shell rubber (B-2).

[0039] From the viewpoints of adhesion and prevention of cracks during molding, it is preferable to contain appropriate amounts of both the reactive group-containing resin (B-1) and the core-shell rubber (B-2). The more reactive group-containing resin (B-1), the higher the reactive group content, and the better the adhesion. Furthermore, the more core-shell rubber (B-2) is contained, the more fracture within the resin layer (II) is suppressed, and therefore the better the adhesion. Furthermore, the more reactive group-containing resin (B-1) is contained, the smaller the tensile elongation at break, and the less the resin layer (I) is stretched, which is advantageous from the viewpoint of preventing cracks during molding. In terms of film handling properties, the more the core-shell rubber (B-2) is contained, the better. The more the core-shell rubber (B-2) is contained, the more the toughness of the resin layer (II) improves, and the better the handling properties of the laminated film become. From the viewpoint of scratch resistance, the smaller the content of the core-shell rubber (B-2), the better. The smaller the content of the core-shell rubber (B-2), the higher the surface hardness and the improved scratch resistance. Furthermore, from the viewpoint of film appearance, the less the core-shell rubber (B-2) is, the better. The less the core-shell rubber (B-2) is, the more the generation of gelled matter due to thermal degradation during melt molding is suppressed, the less foreign matter there is, and the better the film appearance becomes.

[0040] The acetone-insoluble content of the resin composition (B) constituting the resin layer (II) is preferably 5 to 80%. The higher the acetone-insoluble content, the more improved the toughness of the film, resulting in better handling and film-forming properties of the laminated film. Furthermore, the lower the acetone-insoluble content, the more suppressed the generation of thermally degraded resin foreign matter, resulting in better film appearance. Furthermore, the lower the acetone-insoluble content, the smaller the tensile elongation at break of the resin layer (II), so that the resin layer (I) is not stretched during molding, preventing cracking. An acetone-insoluble content of 5 to 80% can achieve both film toughness and film appearance, as well as prevention of cracking during molding. The acetone-insoluble content is more preferably 5 to 75%, even more preferably 5 to 70%, and particularly preferably 5 to 60%. The acetone-insoluble content can be set within a desired range by, for example, adjusting the amount of core-shell rubber added to the resin layer (II). The value of the acetone-insoluble content can be calculated by the method described in the Examples below.

[0041] [Reactive group-containing resin (B-1)] The acrylic resin or reactive group-containing resin (B-1) contained in the resin layer (II) as part of the acrylic resin contains a monomer unit having a reactive group. From the viewpoint of adhesion to the melamine decorative board, the monomer unit having a reactive group is preferably a monomer unit having at least one reactive group selected from the group consisting of a monomer unit having a group reactive with an amino group and a monomer unit having a group reactive with a methylol group (hereinafter also referred to as a monomer unit having a group reactive with an amino group or a methylol group), and more preferably a (meth)acrylic monomer unit having at least one reactive group selected from the group consisting of a (meth)acrylic monomer unit having a group reactive with an amino group and a (meth)acrylic monomer unit having a group reactive with a methylol group. The reactive group-containing resin (B-1) may contain, in addition to the monomer units having a reactive group, aromatic vinyl monomer units such as styrene and other monomer units. Specifically, the reactive group-containing resin (B-1) can contain 3 to 100 mass% of monomer units having a reactive group, 0 to 3 mass% of aromatic vinyl monomer units, and 0 to 97 mass% of other monomer units, totaling 100 mass%.

[0042] When the reactive group-containing resin (B-1) contains a monomer unit having a group reactive to an amino group or a methylol group, it can be brought into contact with a material containing methylol melamine and its derivatives, specifically, the melamine resin of a melamine decorative board or its precursor, and then heated and reacted to adhere to the melamine decorative board.

[0043] Examples of groups reactive with amino groups or methylol groups include hydroxyl groups, carboxyl groups, amino groups, amide groups, acid anhydride groups, imide groups, and epoxy groups. The reactive group-containing resin (B-1) may have one or more of these reactive groups. Two or more reactive group-containing resins (B-1) containing different types and / or different ratios of one or more of these reactive groups may also be used in combination. The reaction temperature of the reactive group varies depending on the presence or absence of a catalyst and the pH value in the reaction, but is, for example, preferably 50 to 200° C., more preferably 110 to 170° C. Melamine decorative boards are usually produced at a temperature of 110 to 170° C., so if the reaction temperature is 110 to 170° C., by laminating the laminate film of the present invention with a melamine substrate and heating it, the laminate film can be sufficiently adhered to the melamine substrate while producing the melamine decorative board.

[0044] Examples of monomers having a reactive group include monomers having a hydroxyl group such as hydroxyalkyl (meth)acrylate; monomers having a carboxyl group such as (meth)acrylic acid, (meth)acryloyloxyalkylcarboxylic acid, and (meth)acryloyloxyaromatic carboxylic acid; monomers having an amino group such as aminoalkyl (meth)acrylate; monomers having an amide group such as alkylamidoalkyl (meth)acrylate; acid anhydride monomers such as maleic anhydride; maleimide monomers such as maleimide and alkylmaleimide; and epoxy group-containing monomers such as glycidyl (meth)acrylate. These may be used alone or in combination of two or more.

[0045] Among these, from the viewpoint of adhesiveness, monomers having a hydroxyl group, a carboxyl group, an acid anhydride group, or an epoxy group as a reactive group are preferred. Furthermore, a monomer having a hydroxyl group, a carboxyl group, or an epoxy group as a reactive group is more preferred, since it does not have a hydrolyzable site such as an acid anhydride and allows for efficient production of a polymer in aqueous polymerization such as emulsion polymerization or suspension polymerization.

[0046] Examples of monomers having a hydroxyl group as a reactive group include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxy-1-methylethyl methacrylate, 2-hydroxybutyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-1-methylethyl acrylate, and 2-hydroxybutyl acrylate. In order to prevent the film from having a poor appearance due to a crosslinking reaction during melt molding, a secondary hydroxyl group is preferred, and specifically, 2-hydroxypropyl methacrylate and 2-hydroxypropyl acrylate are preferred. Furthermore, 2-hydroxypropyl methacrylate is more preferred in terms of its good copolymerizability with, for example, methyl methacrylate. These may be used alone or in combination of two or more.

[0047] Examples of the monomer having a carboxyl group as a reactive group include methacrylic acid and acrylic acid. Examples of monomers having an acid anhydride group as a reactive group include maleic anhydride and glutaric anhydride. Maleic anhydride and glutaric anhydride are preferred in terms of preventing poor film appearance due to crosslinking reactions during melt molding. In the case of maleic anhydride and glutaric anhydride, it is basically necessary to copolymerize aromatic vinyl monomer units, so that methacrylic acid and acrylic acid are preferred in terms of preventing yellowing after weathering tests. These may be used alone or in combination of two or more.

[0048] The content of the monomer unit having a reactive group is preferably 3% by mass or more relative to 100% by mass of the reactive group-containing resin (B-1). From the viewpoints of adhesion and prevention of side reactions, the content is preferably 3% by mass or more and 100% by mass or less, more preferably 3% by mass or more and 80% by mass or less, and even more preferably 10% by mass or more and 30% by mass or less. If the content is 3% by mass or more, the adhesion will be better.

[0049] If the content is 80% by mass or less, 20% by mass or more of a non-reactive monomer is used in combination, and side reactions due to reactive groups can be suppressed. Note that this content is a value calculated from the amount of raw materials charged. Furthermore, when a monomer having a reactive group is water-soluble, dissolution in water can be suppressed by using a water-insoluble monomer in combination, and a polymer can be efficiently produced in aqueous polymerization such as emulsion polymerization or suspension polymerization. Increasing the content of reactive groups reduces the compatibility of the reactive group-containing resin (B-1) with the core-shell rubber (B-2) and the thermoplastic polymer (B-3), which may result in a deterioration in the appearance of the laminated film or an increase in haze. From the viewpoint of maintaining a low appearance and haze of the laminated film, the smaller the amount of reactive groups, the better.

[0050] The content of the aromatic vinyl monomer unit is preferably 0 to 3% by mass relative to 100% by mass of the reactive group-containing resin (B-1). If the content is 3% by mass or less, the weather resistance of the resulting laminate film and melamine decorative board will be good. The content of the aromatic vinyl monomer unit relative to 100% by mass of the reactive group-containing resin (B-1) is more preferably 0 to 1% by mass, and even more preferably 0 to 0.1% by mass. The content of the aromatic vinyl monomer unit is preferably low, and may be 0% by mass.

[0051] Examples of other monomers include acrylic monomers, vinyl cyanide monomers such as acrylonitrile, N-phenylmaleimide, and N-cyclohexylmaleimide. These may be used alone or in combination of two or more. In terms of compatibility with the core-shell rubber (B-2) and the thermoplastic polymer (B-3), adhesion to the resin layer (I), stickiness of the laminated film, and handleability, acrylic monomers are preferred, and methyl methacrylate and butyl acrylate are more preferred. The content of the other monomers is preferably 0 to 96% by mass, and more preferably 20 to 96% by mass, relative to 100% by mass of the reactive group-containing resin (B-1), from the viewpoint of suppressing reactions such as crosslinking due to the reactive groups. The content may be 0% by mass. In particular, when methyl methacrylate and butyl acrylate are used in combination, the content is preferably 70 to 100% by mass of methyl methacrylate and 0 to 30% by mass of butyl acrylate, and more preferably 80 to 100% by mass of methyl methacrylate and 0 to 20% by mass of butyl acrylate, relative to 100% by mass of the total of methyl methacrylate and butyl acrylate.

[0052] The reactive group-containing resin (B-1) can be produced by various polymerization methods such as suspension polymerization, emulsion polymerization, bulk polymerization, solution polymerization, etc. However, when a monomer having an acid anhydride or an imide structure is used as a monomer having a reactive group, hydrolysis occurs during polymerization, and therefore the resin cannot be produced by aqueous polymerization such as suspension polymerization or emulsion polymerization. During the polymerization, a chain transfer agent, other polymerization aids, etc. may be used. Mercaptans are preferred as the chain transfer agent.

[0053] The glass transition temperature (Tg) of the reactive group-containing resin (B-1) is preferably 60°C or higher and lower than 150°C, more preferably 60°C or higher and lower than 100°C, even more preferably 60°C or higher and lower than 98°C, even more preferably 70°C or higher and lower than 95°C, and particularly preferably 75°C or higher and lower than 90°C. If the Tg is 60°C or higher, the melamine decorative board using the laminate film of the present invention will have good heat resistance and water resistance, and in particular, good adhesion after a test in which the film is immersed in hot water at 65°C for 48 hours. Furthermore, the film and raw resin will no longer be sticky and the blocking properties will be reduced, making it easy to unwind from the film roll and easy to handle. Furthermore, poor appearance due to blocking marks will be less likely to occur, making it possible to obtain a laminate film with excellent appearance quality. Furthermore, the resin layer (II) will be less likely to be stretched during molding, which is effective in preventing cracks during molding. If the Tg is less than 150°C, when producing a melamine decorative board laminated with the laminate film of the present invention, the adhesion between the melamine decorative paper and the laminate film is better even if press processing is performed at a lower temperature. That is, the processing conditions when producing a melamine decorative board laminated with the laminate film are relaxed. Furthermore, since the laminate film of the present invention can be melt-molded at a lower temperature, the generation of thermally degraded resin foreign matter is suppressed, and the film appearance is improved.

[0054] The Tg can be determined by the Fox equation using the Tg values ​​of the homopolymers of the components that make up the reactive group-containing resin (B-1).The Fox equation is shown below. 1 / (273+Tg)=Σ(wi / (273+Tgi)) In the formula, Tg is the Tg (°C) of the copolymer (or its mixture), wi is the mass fraction of monomer i, and Tgi is the Tg (°C) of the homopolymer obtained by polymerizing monomer i.

[0055] Here, the Tg value of a homopolymer is determined from the value described in the POLYMER HANDBOOK THIRD EDITION (WILEY INTERSCIENCE) or the value in the catalog of the monomer manufacturer. If the monomer contains a crosslinkable monomer, the Tg is determined for the monomer excluding the crosslinkable monomer.

[0056] [Core-shell rubber (B-2)] The core-shell rubber (B-2) may be any particle having a multilayer structure, and is preferably a rubber particle having a multilayer structure of two or more layers, in which an outer layer containing a hard polymer is formed on an inner layer containing an elastic copolymer. Examples of materials for the core-shell rubber include acrylic rubber, silicone rubber, and butadiene rubber, with acrylic rubber being preferred in terms of transparency and weather resistance.

[0057] When the core-shell rubber (B-2) is an acrylic rubber, it is preferable that the acrylic rubber particles have a multilayer structure of two or more layers, in which a layer containing a hard polymer (a-2) as an outer layer having a structure of one or more layers and obtained by graft polymerization of a monomer having alkyl methacrylate as the main component is formed on a layer containing an elastic copolymer (a-1) as an inner layer having a structure of one or more layers and obtained mainly from alkyl (meth)acrylate. The core-shell rubber (B-2) may also have one or more layers containing an intermediate polymer (a-3) between the layer containing the elastic copolymer (a-1) and the layer containing the hard polymer (a-2). The content of the elastic copolymer (a-1) in the core-shell rubber (B-2) is preferably 10 to 90% by mass, more preferably 20 to 70% by mass, from the viewpoint of preventing cracks during molding of the melamine decorative board. The content of the hard polymer (a-2) in the core-shell rubber (B-2) is preferably 10 to 90% by mass, more preferably 30 to 70% by mass. The content of the intermediate polymer (a-3) in the core-shell rubber (B-2) is preferably 0 to 35% by mass, more preferably 0 to 20% by mass. When the content of the intermediate polymer (a-3) is 35% by mass or less, the balance of the final polymer is good.

[0058] The elastic copolymer (a-1) is preferably a polymer obtained by polymerizing a monomer composition containing an alkyl (meth)acrylate. Here, (meth)acrylate refers to acrylate or methacrylate. The elastic copolymer (a-1) is more preferably a polymer obtained by polymerizing a monomer composition containing an alkyl acrylate. The monomer composition may further contain a monomer other than alkyl (meth)acrylate and a crosslinkable monomer. For example, the elastic copolymer (a-1) may contain 80 to 100 mass% of an alkyl acrylate having an alkyl group with 1 to 8 carbon atoms and an alkyl methacrylate having an alkyl group with 1 to 4 carbon atoms, 0 to 20 mass% of a monomer other than alkyl (meth)acrylate, and 0 to 10 mass% of a crosslinkable monomer (total 100 mass%).

[0059] Examples of alkyl acrylates having an alkyl group having 1 to 8 carbon atoms include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate, and more preferably alkyl acrylates having a low Tg. These may be used alone or in combination of two or more.

[0060] The alkyl acrylate is used as a main component of the monomers constituting the elastic copolymer (a-1). Specifically, the amount of alkyl acrylate used is preferably 30 to 99.9% by mass based on the total amount of monomers constituting the elastic copolymer (a-1). When the amount used is 30% by mass or more, the formability of the film becomes better. The amount used is more preferably 50 to 95% by mass. When the elastic copolymer (a-1) has a structure of two or more layers, the range of the amount used indicates the amount of alkyl acrylate used in the elastic copolymer (a-1) as a whole. For example, when the elastic copolymer (a-1) has a hard core structure, the amount of alkyl acrylate used in the first layer (core) can be less than 30 mass%.

[0061] Examples of alkyl methacrylates having an alkyl group having 1 to 4 carbon atoms include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. These may be used alone or in combination of two or more. The amount of alkyl methacrylate used is preferably 0 to 69.9% by mass, more preferably 0 to 40% by mass, based on the total monomers constituting the elastic copolymer (a-1).

[0062] Examples of the monomer other than alkyl (meth)acrylate include other vinyl monomers copolymerizable with the alkyl (meth)acrylate. Examples of the monomer other than alkyl (meth)acrylate include styrene and acrylonitrile. These may be used alone or in combination of two or more. When a monomer other than alkyl (meth)acrylate is used, the amount used is preferably 0 to 69.9% by mass, more preferably 0 to 20% by mass, based on the total monomers constituting the elastic copolymer (a-1).

[0063] Examples of the crosslinkable monomer include ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, propylene glycol dimethacrylate, and a graft crosslinking agent. These may be used alone or in combination of two or more. The amount of the crosslinkable monomer used is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, based on the total monomers constituting the elastic copolymer (a-1). From the viewpoint of stability in particle generation of the core-shell rubber (B-2), it is preferable to use a graft crosslinking agent as the crosslinkable monomer.

[0064] Examples of the grafting agent include allyl esters, methallyl esters, or crotyl esters of α,β-unsaturated carboxylic acids or unsaturated dicarboxylic acids; triallyl cyanurate; and triallyl isocyanurate. Among these, allyl esters of acrylic acid, methacrylic acid, maleic acid, fumaric acid, etc. are preferred, and allyl methacrylate is more preferred because of its excellent effect. In such a graft crossing agent, the conjugated unsaturated bond of the ester reacts and chemically bonds much faster than the allyl group, methallyl group, or crotyl group, and therefore most of the allyl group, methallyl group, or crotyl group, which reacts more slowly, works effectively during the polymerization of the next layer polymer, providing a graft bond between two adjacent layers.

[0065] The glass transition temperature (Tg) of the elastic copolymer (a-1) is preferably -100°C or higher and lower than 20°C, more preferably -80°C or higher and lower than 10°C, even more preferably -70°C or higher and lower than 0°C, and particularly preferably -60°C or higher and lower than 0°C. If the Tg is -100°C or higher, the resin layer (III) is less likely to be stretched during molding, which is advantageous for preventing cracks during molding. If the Tg is lower than 20°C, toughness can be imparted to the laminate film of the present invention, resulting in better film formability. The Tg can be determined by the method described above.

[0066] Prior to polymerization of the elastic copolymer (a-1), a core having a Tg exceeding 0°C may be polymerized. The core preferably accounts for 0 to 10% by mass of the core-shell rubber (B-2) in terms of the stability of polymer particle generation. The core is preferably obtained by polymerizing monomers including 10 to 50% by mass of alkyl acrylate having an alkyl group with 1 to 8 carbon atoms, 20 to 70% by mass of alkyl methacrylate having an alkyl group with 1 to 4 carbon atoms, 0 to 10% by mass of other vinyl monomers, and 0.1 to 10% by mass of a crosslinkable monomer.

[0067] The rigid polymer (a-2) is preferably a polymer obtained by polymerizing a monomer other than alkyl methacrylate, alkyl acrylate, and alkyl (meth)acrylate. For example, the rigid polymer (a-2) can be obtained by polymerizing, in the presence of the elastic copolymer (a-1), a monomer mixture consisting of 51 to 100 mass% of alkyl methacrylate having an alkyl group with 1 to 4 carbon atoms and 0 to 49 mass% of a monomer other than alkyl acrylate having an alkyl group with 1 to 8 carbon atoms or alkyl (meth)acrylate. The monomers other than alkyl methacrylate having an alkyl group with 1 to 4 carbon atoms, alkyl acrylate having an alkyl group with 1 to 8 carbon atoms, and alkyl (meth)acrylate can be the same as those used in the polymerization of the elastic copolymer (a-1).

[0068] The glass transition temperature (Tg) of the rigid polymer (a-2) is preferably 60°C or higher and lower than 150°C, more preferably 60°C or higher and lower than 140°C, even more preferably 60°C or higher and lower than 130°C, even more preferably 70°C or higher and lower than 120°C, and particularly preferably 75°C or higher and lower than 110°C. If the Tg is 60°C or higher, the resin layer (II) or the resin layer (III) described below is less likely to be stretched during molding, which is advantageous for preventing cracks during molding. If the Tg is lower than 150°C, the laminated film of the present invention can be molded at a lower temperature during melt molding, which suppresses the generation of thermally degraded resin foreign matter and improves the film appearance. The Tg can be determined by the method described above.

[0069] The intermediate polymer (a-3) is preferably a polymer obtained by polymerizing a monomer composition containing an alkyl acrylate, an alkyl methacrylate, a monomer other than alkyl (meth)acrylate, and a crosslinkable monomer. The intermediate polymer (a-3) is more preferably a polymer obtained by polymerizing a monomer composition containing an alkyl acrylate having an alkyl group containing 1 to 8 carbon atoms, an alkyl methacrylate having an alkyl group containing 1 to 4 carbon atoms, a monomer other than alkyl (meth)acrylate, and a crosslinkable monomer. For example, the intermediate polymer (a-3) may contain 10 to 90% by mass of an alkyl acrylate having an alkyl group containing 1 to 8 carbon atoms, 90 to 10% by mass of an alkyl methacrylate having an alkyl group containing 1 to 4 carbon atoms, 0 to 20% by mass of a monomer other than alkyl (meth)acrylate, and 0 to 10% by mass of a crosslinkable monomer (total 100% by mass).

[0070] The monomers used in the intermediate polymer (a-3) may be the same as those used in the polymerization of the elastic copolymer (a-1). Preferably, the alkyl acrylate content (monomer composition ratio) in the intermediate polymer (a-3) is lower than that in the elastic copolymer (a-1) and higher than that in the rigid polymer (a-2).

[0071] The average particle size of the core-shell rubber (B-2) is preferably 0.01 to 0.5 μm, more preferably 0.08 to 0.3 μm. In particular, from the viewpoint of film formability, the average particle size is preferably 0.08 μm or more. The average particle size is a value measured by the method described below.

[0072] The method for producing the core-shell rubber (B-2) is not particularly limited. The elastic copolymer (a-1) and the rigid polymer (a-2) can be produced, for example, by emulsion polymerization. Alternatively, they can be produced by emulsion suspension polymerization, in which the emulsion polymerization is followed by conversion to a suspension polymerization system during polymerization of the polymer constituting the outermost layer. The polymerization temperature is appropriately selected depending on the type and amount of the polymerization initiator used, but is preferably 40 to 120°C, more preferably 60 to 95°C. Known polymerization initiators can be used as the polymerization initiator. The polymerization initiator can be added to either the aqueous phase or the monomer phase, or both.

[0073] Examples of emulsifiers that can be used in emulsion polymerization include anionic, cationic, and nonionic surfactants, with anionic surfactants being preferred. Examples of anionic surfactants include carboxylate surfactants such as potassium oleate, sodium stearate, sodium myristate, sodium N-lauroylsarcosinate, and dipotassium alkenylsuccinate; sulfate surfactants such as sodium lauryl sulfate; sulfonate surfactants such as dioctyl sodium sulfosuccinate, sodium dodecylbenzenesulfonate, and sodium alkyldiphenyletherdisulfonate; and phosphate surfactants such as polyoxyethylene alkylphenylether sodium phosphate. These surfactants may be used alone or in combination of two or more.

[0074] The polymer latex obtained by emulsion polymerization can be filtered, for example, through a filter with a mesh size of 100 μm or less, and then separated and recovered by methods such as acid coagulation, salt coagulation, freeze coagulation, spray drying, etc. For the acid coagulation, inorganic acids such as sulfuric acid, hydrochloric acid, and phosphoric acid, and organic acids such as acetic acid, etc. can be used. For the salt coagulation, inorganic salts such as sodium sulfate, magnesium sulfate, aluminum sulfate, and calcium chloride, and organic salts such as calcium acetate and magnesium acetate can be used. These can be used alone or in combination of two or more. The separated and recovered polymer can be further washed, dehydrated, dried, etc. to obtain the core-shell rubber (B-2).

[0075] [Thermoplastic polymer (B-3)] The thermoplastic polymer (B-3) may be any polymer other than the reactive group-containing resin (B-1) and the core-shell rubber (B-2), and is preferably a polymer obtained by polymerizing a monomer containing alkyl methacrylate as the main component.

[0076] The thermoplastic polymer (B-3) is more preferably a polymer obtained by polymerizing a monomer other than alkyl methacrylate, alkyl acrylate, and alkyl (meth)acrylate. For example, the thermoplastic polymer (B-3) may be a polymer obtained by polymerizing 50 to 99.9 mass% of alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms, 0.1 to 50 mass% of alkyl acrylate, and 0 to 49.9 mass% of a monomer other than alkyl (meth)acrylate, totaling 100 mass%.

[0077] Examples of the alkyl methacrylate include methyl methacrylate, ethyl methacrylate, and butyl methacrylate, with methyl methacrylate being preferred. These may be used alone or in combination of two or more.

[0078] Examples of alkyl acrylates include methyl acrylate, ethyl acrylate, and butyl acrylate, which may be used alone or in combination of two or more.

[0079] Examples of monomers other than alkyl (meth)acrylates include aromatic vinyl monomers such as styrene, cyanide vinyl monomers such as acrylonitrile, unsaturated dicarboxylic acid anhydrides such as maleic anhydride and itaconic anhydride, N-phenylmaleimide, and N-cyclohexylmaleimide. These may be used alone or in combination of two or more.

[0080] The method for producing the thermoplastic polymer (B-3) is not particularly limited, and various polymerization methods such as suspension polymerization, emulsion polymerization, and bulk polymerization can be used. During polymerization, a chain transfer agent, other polymerization aids, etc. may be used. The chain transfer agent is not particularly limited, but mercaptans are preferred.

[0081] The mass average molecular weight of the thermoplastic polymer (B-3) is preferably 300,000 or less, from the viewpoint of providing a suitable elongation when the film raw material resin is melted and achieving good film formability. Furthermore, the mass average molecular weight is preferably 10,000 or more, from the viewpoint of preventing the film from becoming brittle and therefore less likely to break during film formation and handling. For example, a mass average molecular weight of 10,000 to 300,000 is preferred. The mass average molecular weight is a value measured by the method described below.

[0082] The glass transition temperature (Tg) of the thermoplastic polymer (B-3) is preferably 60°C or higher and lower than 150°C, more preferably 60°C or higher and lower than 140°C, even more preferably 60°C or higher and lower than 130°C, even more preferably 70°C or higher and lower than 120°C, and particularly preferably 75°C or higher and lower than 110°C. If the Tg is 60° C. or higher, the resin layer (II) or the resin layer (III) described below is less likely to be stretched during molding, which is advantageous in preventing cracks during molding. If the Tg is less than 150°C, the laminated film of the present invention can be melt-molded at a lower temperature, which suppresses the generation of foreign matter due to thermal degradation of the resin and improves the appearance of the film.

[0083] The Tg can be determined by the method described above.

[0084] When the thermoplastic polymer (B-3) is used, the content of the thermoplastic polymer (B-3) is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 1 part by mass or more and 5 parts by mass or less, and even more preferably 1.5 parts by mass or more and 4 parts by mass or less, relative to the total mass of the resin composition (b).

[0085] [Additive (B-4)] The additive (B-4) is a compound other than the reactive group-containing resin (B-1), the core-shell rubber (B-2), and the thermoplastic polymer (B-3), and examples thereof include stabilizers, lubricants, plasticizers, foaming agents, fillers, colorants, and ultraviolet absorbers.

[0086] For example, in order to provide the film with weather resistance to protect the substrate, an ultraviolet absorber may be contained as the additive (B-4). The molecular weight of the ultraviolet absorber is preferably at least 300, more preferably at least 400. When the molecular weight is at least 300, bleeding out of the ultraviolet absorber in the laminated film is reduced. As the ultraviolet absorber, a benzotriazole-type ultraviolet absorber having a molecular weight of 400 or more and a triazine-type ultraviolet absorber having a molecular weight of 400 or more are preferred. In terms of maintaining ultraviolet shielding ability for a long period of time, a triazine-type ultraviolet absorber having a molecular weight of 400 or more is more preferred.

[0087] Commercially available benzotriazole-type ultraviolet absorbers with a molecular weight of 400 or more include, for example, "Tinuvin 234" (trade name, manufactured by BASF Japan Ltd.); "Adekastab LA-31" (trade name, manufactured by ADEKA Corporation); and "Tinuvin 326" (trade name, manufactured by BASF Corporation). Commercially available triazine-type ultraviolet absorbers with a molecular weight of 400 or more include, for example, "Tinuvin 1577" (trade name, manufactured by BASF Japan Ltd.) and "Adekastab LAF70" (trade name, manufactured by ADEKA Corporation). These may be used alone or in combination of two or more.

[0088] The amount of the ultraviolet absorber added is preferably 0 to 20 parts by mass per 100 parts by mass of the total of the reactive group-containing resin (B-1) and the core-shell rubber (B-2) from the viewpoint of weather resistance, and more preferably 1 to 5 parts by mass from the viewpoint of preventing mold contamination during molding and bleed-out resistance.

[0089] In order to further improve weather resistance, a radical scavenger such as a hindered amine light stabilizer may be used in combination with the ultraviolet absorber. Commercially available radical scavengers include, for example, "ADK STAB LA-57," "ADK STAB LA-62," "ADK STAB LA-67," "ADK STAB LA-63," and "ADK STAB LA-68" (all trade names, manufactured by ADEKA Corporation); "SANOL LS-770," "SANOL LS-765," "SANOL LS-292," "SANOL LS-2626," "SANOL LS-1114," and "SANOL LS-744" (all trade names, manufactured by Sankyo Lifetech Co., Ltd.). These may be used alone or in combination of two or more.

[0090] Furthermore, as the radical scavenger such as a hindered amine light stabilizer, a high molecular weight hindered amine stabilizer can also be used from the viewpoint of bleed-out resistance. The molecular weight of the hindered amine stabilizer is preferably 1,000 or more, more preferably 2,000 or more. Examples of hindered amine stabilizers with a molecular weight of 2000 or more include "Chimassorb 2020" and "Chimassorb 944" (both trade names, manufactured by BASF Japan Ltd.).

[0091] From the viewpoint of bleed-out resistance, the amount of the radical scavenger added is preferably 0 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, per 100 parts by mass of the total of the reactive group-containing resin (B-1) and the core-shell rubber (B-2).

[0092] In order to provide an anti-blocking effect, an anti-blocking agent such as silica particles may be contained as the additive (B-4). An example of a commercially available antiblocking agent is "AEROSIL R976" (manufactured by Nippon Aerosil Co., Ltd.).

[0093] The amount of antiblocking agent added is preferably 0 parts by mass or more, more preferably 0.01 parts by mass or more, relative to 100 parts by mass of the total of the reactive group-containing resin (B-1) and the core-shell rubber (B-2). On the other hand, it is preferably less than 2 parts by mass, more preferably less than 1.5 parts by mass. The above upper and lower limits can be arbitrarily combined. For example, it is preferably 0 to 2 parts by mass, more preferably 0.01 to 1.5 parts by mass. When the amount of the antiblocking agent added is 0.01 parts by mass or more, a sufficient blocking prevention effect can be achieved, and when the amount is 0.5 parts by mass or less, a decrease in the transparency of the resulting laminated film can be suppressed and the occurrence of fisheyes can be reduced.

[0094] Furthermore, in order to prevent sticking to the press plate when the melamine decorative board is produced by thermocompression molding, a release agent may be contained as the additive (B-4). Examples of the release agent include silicone compounds, fluorine compounds, alkyl alcohols, and alkyl carboxylic acids. Among these, alkyl carboxylic acids are preferred from the standpoints of availability and economy. Examples of alkylcarboxylic acids include linoleic acid, vaccenic acid, stearic acid, oleic acid, margaric acid, palmitoleic acid, palmitic acid, and pentadecylic acid. These may be used alone or in combination of two or more.

[0095] The amount of release agent added is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, per 100 parts by mass of the total of the reactive group-containing resin (B-1) and the core-shell rubber (B-2), in order to prevent sticking to the press plate. On the other hand, it is preferably 2 parts by mass or less, more preferably 0.5 parts by mass or less. The above upper and lower limits can be arbitrarily combined. For example, it is preferably 0.01 to 2 parts by mass, more preferably 0.1 to 0.5 parts by mass.

[0096] [Acrylic resin layer, film, laminated film] The laminate of the present invention has an acrylic resin layer including at least a resin layer (I) made of an acrylic resin composition. The acrylic resin layer may be a film consisting of only the resin layer (I), or may be a laminate film including the resin layer (I) and another resin layer. The other resin layer may be a resin layer (II). In order to obtain a laminate having better weather resistance, it is preferable that the acrylic resin layer has a transmittance of less than 1% at a wavelength of 380 nm after 480 hours of metal weather exposure testing.

[0097] The YI of the acrylic resin layer is preferably less than 10, more preferably 8 or less, and even more preferably 5 or less. When the YI is less than 10, the design of the base layer becomes clearer. On the other hand, there is no particular restriction on the lower limit of YI, and it is preferably 0. The acrylic resin layer will hereinafter also be referred to as a "film" or a "laminated film."

[0098] The thickness of the acrylic resin layer of the present invention is preferably from 10 to 100 μm, more preferably from 20 to 80 μm, and even more preferably from 25 to 60 μm. If the thickness is 10 μm or more, the film can be easily produced and the area concentration of the ultraviolet absorber will be sufficient, so that the resulting melamine decorative board can be endowed with sufficient weather resistance. If the thickness is 100 μm or less, the acrylic resin layer has adequate flexibility, preventing peeling when the resulting melamine decorative board is cut. It is also economically advantageous in terms of mass per unit area. Furthermore, film-forming properties are stable, facilitating the production of laminated films. Furthermore, when laminated on a melamine decorative board, the pencil hardness of the decorative board increases, improving scratch resistance. When the acrylic resin layer of the present invention is a laminated film of resin layer (I) and resin layer (II), when laminating it to a melamine substrate, it is preferable that the resin layer (II) made of the acrylic resin composition (B) is used as the lamination layer facing the substrate, and the resin layer (I) made of the acrylic resin composition (A) is used as the surface layer facing away from the substrate.

[0099] The thickness of the resin layer (I) is preferably from 1 to 99.5 μm, more preferably from 5 to 90 μm, and even more preferably from 20 to 80 μm. If the thickness of the resin layer (I) is 1 μm or more, the weather resistance and water resistance of the resulting melamine decorative board will be good. Also, if the thickness of the resin layer (I) is 99.5 μm or less, it is economically advantageous in terms of mass per unit area.

[0100] The thickness of the resin layer (II) is preferably 99 μm or less, more preferably 10 μm or less, and more preferably 7 μm or less, while it is preferably 0.5 μm or more, more preferably 2 μm or more, and even more preferably 3 μm or more. If the thickness of the resin layer (II) is 0.5 μm or more, the melamine adhesiveness is improved, and if the thickness of the resin layer (II) is 99 μm or less, it is economically advantageous in terms of mass per unit area.

[0101] The laminated film may have a layer (hereinafter referred to as an intermediate layer) other than the surface layer, and a known resin may be used as the intermediate layer. For example, compositions such as polyvinyl chloride resin, polycarbonate resin, ABS resin, AS resin, MBS resin, MS resin, styrene resin, methacrylic resin, polyglutarimide, glutaric anhydride polymer, lactone-cyclized methacrylic resin, polyvinylidene fluoride, fluorine-containing resin, polyethylene terephthalate resin, polybutylene terephthalate resin, TPO resin, polyethylene resin, and polypropylene resin are exemplified, and from the viewpoint of compatibility with the resin layer (I) and the resin layer (II), acrylic resin and fluorine-containing resin are more preferred.

[0102] The number of intermediate layers is preferably 3 or less, and more preferably 2 or less. If the number of intermediate layers is more than 3, film formation may be difficult.

[0103] The haze of the laminate film is preferably 20% or less, more preferably 10% or less. If the haze is 20% or less, for example, when used for protecting a decorative board, the pattern on the decorative board will not become cloudy, and a decorative board with excellent design can be obtained.

[0104] [Method of manufacturing acrylic resin layer and laminated film] From the viewpoint of productivity, the method for producing the acrylic resin layer of the present invention is preferably a method of forming a laminate structure of the resin layer (I) and the resin layer (II) by co-extrusion through a feed block die or a multi-manifold die. Alternatively, a method can be used in which the resin layer (I) and the resin layer (II) are each formed into a film by melt extrusion using a T-die, and the two films are laminated by thermal lamination. Furthermore, an extrusion lamination method can be used in which one resin layer is formed into a film and then the other resin layer is laminated by melt extrusion. When melt extrusion is performed, the resin composition in a molten state can be extruded while being filtered through a screen mesh of 200 mesh or more to remove nuclei and impurities that may cause surface defects.

[0105] The extruder used to produce pellets is preferably one equipped with one or more vent ports. This is because heating the acrylic resin composition (B) converts the acid into an anhydride, generating water and / or methanol and / or decomposition products, which can be removed through the vent port to prevent poor appearance due to foaming during film production. The extruder used may be a single-screw or multi-screw extruder. For the same reason, it is preferable to use an extruder equipped with a vent for film production.

[0106] Furthermore, in order to prevent foaming and thermal degradation of the acrylic resin composition (B), it is preferable to use a coating method in which a solution containing the acrylic resin composition (B) is applied to the resin layer (I) formed into a film to laminate the resin layer (II). For example, a solution in which the acrylic resin composition (B) is dissolved in a solvent such as an organic solvent is applied to the resin layer (I) by a printing method such as gravure printing, screen printing, or offset printing, or a coating method such as blade coating or rod coating, and the resulting solution is then heated and dried to remove the solvent. Alternatively, the resin layer (I) may be laminated by applying a solution containing the acrylic resin composition (A) to the resin layer (II) formed into a film.

[0107] Examples of the solvent include alcohol-based solvents such as methanol and ethanol; aromatic solvents such as xylene and toluene; aliphatic hydrocarbon-based solvents such as hexane and pentane; halogenated hydrocarbon-based solvents such as chloroform and carbon tetrachloride; phenol-based solvents such as phenol and cresol; ketone-based solvents such as methyl ethyl ketone and methyl isobutyl ketone; ether-based solvents such as diethyl ether and methoxytoluene; fatty acid-based solvents such as formic acid and acetic acid; acid anhydride-based solvents such as acetic anhydride; ester-based solvents such as ethyl acetate and n-propyl acetate; nitrogen-containing solvents such as dimethylformamide and dimethylacetamide; sulfur-containing solvents such as thiophene and dimethyl sulfoxide; solvents having two or more functional groups such as diacetone alcohol and 2-methoxyethanol (methyl cellosolve), and water. Among these, dimethylformamide and dimethylacetamide are preferred from the viewpoint of dissolving power. These may be used alone or in combination of two or more.

[0108] Depending on the printability or coatability of the resin composition as a paint, additives for improving solution properties such as anti-skinning agents, thickeners, anti-settling agents, anti-sagging agents, defoamers, leveling agents, etc. Furthermore, additives for improving coating film performance such as extender pigments, light stabilizers, ultraviolet absorbers, antioxidants, antibacterial agents, anti-fungal agents, flame retardants, etc. may be added to the resin composition.

[0109] [Protective film, melamine decorative panel] The acrylic resin layer of the present invention has excellent adhesiveness and can be adhered to various substrates, making it suitable for use as a protective film. In particular, the acrylic resin layer of the present invention has excellent weather resistance, making it suitable for use as a protective film for substrates having a lightfastness rating of III or higher according to ASTM D4303. Examples of such substrates include melamine resins, and the acrylic resin layer of the present invention can be suitable for use as a protective film for melamine decorative boards having a lightfastness rating of III or higher according to ASTM D4303. It also has excellent resistance to water whitening, making it suitable for outdoor use.

[0110] Melamine decorative boards are used on horizontal surfaces such as desks and counters, and on vertical surfaces such as walls, and their configuration and manufacturing method are described in detail in the Decorative Board Handbook (published by the New Construction Materials Research Institute in 1973), etc. These melamine decorative boards can be obtained, for example, by impregnating decorative paper for decorative boards with melamine resin, laminating the dried melamine resin-impregnated paper with resin-impregnated core paper as a core material layer, and, if necessary, impregnating overlay paper with melamine resin to protect the pattern of the decorative paper, laminating the dried melamine resin-impregnated overlay paper with balance paper as the bottom layer to suppress warping, and then thermocompressing the resulting product.

[0111] The melamine resin-impregnated paper may be, for example, decorative paper for decorative laminates impregnated with melamine-formaldehyde resin and dried. The resin-impregnated core paper may be, for example, core paper for decorative laminates impregnated with a slurry containing a resin liquid mainly composed of phenol-formaldehyde resin, melamine-formaldehyde resin, or a mixture thereof, and an inorganic filler such as aluminum hydroxide or calcium carbonate, and dried. Thermocompression molding can be carried out, for example, by laminating a resin-impregnated core paper and a melamine resin-impregnated paper (melamine base material) with the laminated film of the present invention, under conditions of a temperature of 110 to 170°C, a pressure of 5 to 10 MPa, and a time of 10 to 90 minutes.

[0112] Examples of pigments or dyes used in the melamine-impregnated paper include titanium oxide, insoluble azo (red), condensed azo (red), quinacridone (red), anthraquinone (red), thioindigo (red), perylene (red), perinone (orange), insoluble azo (yellow), quinaphthalone, isoindolinone, iron oxide (yellow), cyanine blue, cyanine green, iron oxide (brown), iron oxide (black), and carbon black. Among these, pigments and dyes with a Lightfastness rating of III or higher according to ASTM D4303 are preferred, including azo pigments other than condensed azo pigments. Specific examples of condensed azo pigments or dyes include disazo-type azo pigments or dyes. Specifically, for example, PigmentRed170, PigmentRed112, PigmentRed2, PigmentRed4, PigmentRed5, PigmentRed8, PigmentRed22, PigmentRed23, PigmentRed112, PigmentRed146, PigmentRed266, PigmentRed268, PigmentRed269, PigmentOrange13, P PigmentOrange5, PigmentOrange16, PigmentYellow1, PigmentYellow12, PigmentYellow13, PigmentYellow14, PigmentYellow17, PigmentYellow55, PigmentYellow74, PigmentYellow126, PigmentYellow127, and PigmentYellow176.

[0113] Lightfastness ratings based on ASTM D4303 can be quantitatively evaluated by ΔE before and after weather resistance testing, and are rated I to V depending on the ΔE value. Specifically, if ΔE is less than 4, it is rated as rating I, if ΔE is between 4 and 8, it is rated as rating II, if ΔE is between 8 and 16, it is rated as rating III, if ΔE is between 16 and 24, it is rated as rating IV, and if ΔE is 24 or more, it is rated as rating V.

[0114] Lightfastness ratings can also be evaluated using BS 1006 as a standard, with Lightfastness rating I, based on ASTM D4303, being expressed as 7-8, rating II as 6, rating III as 4-5, rating IV as 2-3, and rating V as 1.

[0115] The film used in the laminate of the present application is preferably used as a protective film for a substrate having a lightfastness rating of III or higher based on the above-mentioned ASTM D4303 standard, and more preferably a protective film for a substrate having such a rating of III to V.

[0116] When laminating the acrylic resin layer or substrate protective film layer of the present invention to a melamine substrate, it is preferable to heat-seal the resin layer (II) composed of the acrylic resin composition (B) so that it faces the melamine substrate. This method allows lamination without the use of adhesives or pressure-sensitive adhesives. Lamination can be performed continuously or discontinuously, for example, by a discontinuous lamination method using a heat press. In particular, when producing a melamine decorative board, laminating the melamine substrate and the laminate film of the present invention and then heat-pressing the laminate film allows the laminate film to be laminated simultaneously with the production of the melamine decorative board, which is advantageous because it reduces the number of steps. Furthermore, the laminate film of the present invention exhibits excellent adhesion after a hot water test, even when the pressing conditions for lamination to the melamine substrate are low temperature and short time, which is industrially advantageous. [Example]

[0117] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" means "parts by mass." The abbreviations in the examples are as follows.

[0118] MMA: Methyl methacrylate MA: Methyl acrylate EA: Ethyl acrylate BMA: Butyl methacrylate BA: Butyl acrylate HPMA: 2-hydroxypropyl methacrylate MAA: methacrylic acid St: styrene AMA: Allyl methacrylate BDMA: 1,3-butylene glycol dimethacrylate CHP: Cumene hydroperoxide tBH: t-butyl hydroperoxide LPO: Lauryl peroxide nOM: n-octyl mercaptan RS610NA: mono-n-dodecyloxytetraoxyethylene sodium phosphate (trade name: "Phosphanol RS-610NA", manufactured by Toho Chemical Industry Co., Ltd.) LA31: ADEKA Corporation, "ADEKA STAB LA-31RG" (product name) LAF70: ADEKA Corporation, "ADEKA STAB LAF70" (product name) Tv326: BASF's "Tinuvin 326" (product name) 2020: BASF, "Chimassorb2020" (product name) R976: AEROSIL R976 (product name) manufactured by Nippon Aerosil 1076: BASF, "Irganox 1076" (product name) VH5001: Methacrylic resin (PMMA), manufactured by Mitsubishi Chemical Corporation, "ACRYPET VH5001" (product name) VH: Mitsubishi Rayon Co., Ltd., "ACRYPET VH001" (product name) L1000: Acrylic polymer external lubricant, manufactured by Mitsubishi Chemical Corporation, "Metablen L-1000" (product name) XIRAN3500: "XIRAN3500" (product name) made by POLYSCOPE MBR D-05: "Dymic Color MBR D-05" (product name) manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd. MBR165: "Dymic Color MBR165" (product name) manufactured by Dainichi Seika Color & Chemicals Mfg. Co., Ltd. LAF70, Tv326, and LA31 have the physical properties shown in Table 1 in a 10 mg / L chloroform solution.

[0119] [Table 1]

[0120] In the examples, various physical properties were measured according to the following methods.

[0121] (1) Mass average molecular weight (Mw) and molecular weight distribution The mass average molecular weight (Mw) and number average molecular weight of the polymer were determined by the following method. A sample prepared by dissolving the polymer in tetrahydrofuran was subjected to measurement at 40°C using gel permeation chromatography (model name: "HLC-8200", manufactured by Tosoh Corporation), columns (trade name: "TSK-GEL SUPER MULTIPORE HZ-H", manufactured by Tosoh Corporation, inner diameter 4.6 mm × length 15 cm × 2 columns), and an eluent (tetrahydrofuran). The mass average molecular weight (Mw) and number average molecular weight were determined from a calibration curve using standard polystyrene. Furthermore, the molecular weight distribution was calculated using the following formula.

[0122] Molecular weight distribution = (mass average molecular weight) / (number average molecular weight).

[0123] (2) Glass transition temperature (Tg) The glass transition temperature of the polymer was calculated from the Fox equation using the values ​​listed in the Polymer Handbook (J. Brandrup, Interscience, 1989) or the values ​​in the catalogues of the monomer manufacturers.

[0124] (3) Average particle size The average particle size of the core-shell rubber was measured by measuring the final particle size of the polymer latex obtained by emulsion polymerization using a light scattering photometer (product name: "DLS-700", manufactured by Otsuka Electronics Co., Ltd.) by dynamic light scattering.

[0125] (4) Acetone insolubles 50 ml of acetone was added to 0.5 g of the obtained acrylic resin composition (A) or (B) and stirred at 65°C for 4 hours. The mixture was then centrifuged at 4°C and 14,000 rpm for 30 minutes. After removing the supernatant, 50 ml of acetone was added again and centrifuged again under the same conditions. After removing the supernatant, the precipitated gel was vacuum dried for 8 hours and its mass was measured. The acetone-insoluble content was calculated using the following formula: Acetone insoluble matter (%) = (mass of acetone insoluble matter (g) / 0.5) x 100

[0126] (5) Thickness of resin layers (I) and (II) The laminated film was cut into a suitable size, and the thicknesses of the resin layers (I) and (II) were measured using a reflection spectroscopic film thickness meter FE3000 (trade name, manufactured by Otsuka Electronics Co., Ltd.).

[0127] (6) Total light transmittance (TT), haze (Haze), yellowness (YI), color difference (ΔE) The total light transmittance (TT) of the obtained laminated film was evaluated in accordance with JIS K7361-1, the haze in accordance with JIS K7136, the yellowness index (YI) in accordance with JIS K7373, and the color difference (ΔE) in accordance with JIS K5600-4-6.

[0128] (7)380nm, 400nm transmittance The transmittance of the laminated film at 380 nm and 400 nm was measured using an ultraviolet-visible spectrophotometer (product name: "V-630", manufactured by JASCO Corporation).

[0129] (8) Melamine substrate endothermic peak temperature Using a DSC6200 (product name, manufactured by SII Nanotechnology), the endothermic peak temperature was measured when the melamine substrate was heated from 25°C to 200°C at a rate of 10°C / min under a nitrogen gas flow, and the first endothermic peak temperature was taken as the melamine substrate endothermic peak temperature.

[0130] (9) Adhesion evaluation A melamine decorative panel at room temperature was cut with a cutter knife into a grid of 100 squares spaced 1 mm apart, and peelability was checked using cellophane tape (manufactured by Nichiban Co., Ltd.). This test was performed in the initial state, after the boiling test, and after the hot water test, and the results were rated as follows: no peeling at all (class 0); less than 5% peeling of the mass (class 1); less than 15% peeling of the mass (class 2); less than 35% peeling of the mass (class 3); less than 65% peeling of the mass (class 4); and more than 65% peeling of the mass (class 5).

[0131] (10) Storage modulus (E') After preparing a monolayer film consisting of layer (I), a test piece was cut into a width of 6 mm and a length of 20 mm, and the test piece was measured using an EXSTAR DMS6100 manufactured by Seiko Instruments Inc. in a tensile mode at a heating rate of 2°C / min and a measurement frequency of 0.1 Hz.

[0132] (11) Moisture and heat resistance The laminated film was left standing for 21 days under conditions of a temperature of 80°C and a relative humidity of 90%, and then the ejection property of the ultraviolet absorber was evaluated by the change in haze (ΔHaze) before and after the test.

[0133] (12) Weather resistance evaluation A metal weather meter (model name: "KU-R4CI-A", manufactured by Daipla Wintes Co., Ltd.) was used, and the irradiation intensity was 65 mW / cm. 2 The test was conducted using a 24-hour cycle consisting of 20 hours of irradiation (53°C, 50% RH) and 4 hours of irradiation and spraying (30°C, 98% RH) (including 30 seconds of spraying) using a KF-1 filter (295-780 nm). After 10 cycles (480 hours later), the color difference (ΔE), 380 nm transmittance, and 400 nm transmittance were measured.

[0134] <Production Example 1: Production of Core-Shell Rubbers (A-1A) and (B-2A)> A vessel equipped with a stirrer was charged with 8.5 parts of deionized water, and then the following component (ii) was added thereto while stirring, followed by stirring for 20 minutes to prepare an emulsion. Next, 191.5 parts of deionized water and the following component (i) were placed in a polymerization vessel equipped with a cooler, and the temperature was raised to 70° C. Next, the prepared emulsion was added dropwise to the polymerization vessel over 8 minutes while stirring under nitrogen, and the reaction was continued for 15 minutes. Subsequently, the following component (iii) was added dropwise to the polymerization vessel over 90 minutes, and the reaction was continued for 60 minutes to obtain a latex of an elastic copolymer, the Tg of which was −48° C.

[0135] Subsequently, the following component (iv) was added dropwise to the polymerization vessel over 45 minutes, and the reaction was continued for 60 minutes to form an intermediate polymer on the elastic copolymer. The Tg of the intermediate polymer alone was 20°C. Subsequently, the following component (v) was added dropwise to the polymerization vessel over 140 minutes, and the reaction was continued for 60 minutes to form a hard polymer on the intermediate polymer. Through these steps, a latex containing 100 parts of core-shell rubber (A-1A) was obtained. The Tg of the hard polymer alone was 84°C. The average particle size of the core-shell rubber (A-1A) measured after polymerization was 0.12 μm. This core-shell rubber (A-1A) latex was filtered through a filter with a mesh size of 50 μm. Then, it was coagulated using calcium acetate, filtered, washed with water, and dried to obtain a core-shell rubber (A-1A). The core-shell rubber (A-1A) is the same as the core-shell rubber (B-2A) used in the examples described later.

[0136] (i) Sodium formaldehyde sulfoxylate 0.2 parts Ferrous sulfate 0.0001 parts Disodium ethylenediaminetetraacetate 0.0003 parts (ii) MMA 0.3 Division BA 4.5 parts AMA 0.05 parts BDMA 0.2 part CHP 0.025 part RS610NA 1.1 part (iii) MMA 1.5 Division BA 22.5 parts AMA 0.25 parts BDMA 1.0 parts CHP 0.016 parts (iv) MMA 6.0 Division BA 4.0 Department AMA 0.075 parts CHP 0.013 parts (v) MMA 55.2 BA 4.8 parts nOM 0.22 parts tBH 0.075 parts

[0137] <Production Examples 2 and 3: Production of Core-Shell Rubbers (A-1B) and (B-2B)> In Production Examples 2 and 3, core-shell rubbers (A-1B) and (B-2B) were obtained in the same manner as in Production Example 1, except that the monomers used were changed as shown in Table 2.

[0138] <Production Example 2: Production of Core-Shell Rubber (A-1B)> Under a nitrogen atmosphere, 206 parts of deionized water was placed in a reaction vessel equipped with a reflux condenser and heated to 80°C. Component (i) shown below was added, and while stirring, 1 / 10 of raw material (ii) shown below (part of the raw materials for the elastic copolymer (a-1)) was charged and held for 15 minutes. The remaining raw material (ii) was then continuously added so that the rate of increase of the monomer mixture relative to water was 8% by mass / hour. The mixture was then held for 1 hour to allow polymerization to occur, yielding a polymer latex. Subsequently, 0.2 parts of sodium formaldehyde sulfoxylate was added to the polymer latex. After holding for 15 minutes, the mixture was stirred under a nitrogen atmosphere at 80°C, and raw material (iii) shown below (part of the raw materials for the elastic copolymer (a-1)) was continuously added so that the rate of increase of the monomer mixture relative to water was 4% by mass / hour. The mixture was then held for 2 hours to allow polymerization to occur, yielding a latex of elastic copolymer (a-1).

[0139] To this latex of elastic copolymer (a-1), 0.2 parts by mass of sodium formaldehyde sulfoxylate was added. After 15 minutes of stirring at 80°C under a nitrogen atmosphere, raw material (iv) (raw material for rigid polymer (a-2)) shown below was continuously added so that the rate of increase of the monomer mixture relative to water was 10% by mass / hour. The mixture was then held for 1 hour to allow polymerization, yielding a latex of core-shell rubber (A-1B). The particle size of the core-shell rubber (A-1B) was 0.28 μm.

[0140] The core-shell rubber (A-1B) latex was filtered through a filter with a mesh size of 50 μm, and then subjected to coagulation, aggregation, and solidification reactions using calcium acetate. The resulting mixture was then filtered, washed with water, and dried to obtain the core-shell rubber (A-1B).

[0141] (i) Sodium formaldehyde sulfoxylate 0.4 parts Ferrous sulfate 0.00004 parts Disodium ethylenediaminetetraacetate 0.00012 parts (ii) MMA 11.25 BA 12.5 parts St 1.25 part AMA 0.094 parts BDMA 0.75 part tBH 0.044 parts RS610NA 0.75 part (iii) BA 30.9 Division St 6.6 part AMA 0.66 parts BDMA 0.09 part CHP 0.11 part RS610NA 0.6 part (iv) MMA 35.6 Division MA 1.9 parts nOM 0.11 parts tBH 0.06 parts

[0142] <Production Example 3: Production of Core-Shell Rubber (B-2B)> Under a nitrogen atmosphere, 153 parts of deionized water was placed in a reaction vessel equipped with a reflux condenser and heated to 80°C. Component (i) below was added, and then component (ii) below was added while stirring. The mixture was then maintained for 1 hour to allow polymerization to occur, yielding a polymer latex. Next, 0.1 parts of sodium formaldehyde sulfoxylate was added to the polymer latex. After 15 minutes of stirring, the mixture was stirred at 80°C under a nitrogen atmosphere while adding component (iii) below. The mixture was then held for 1 hour to allow polymerization, yielding a latex of core-shell rubber (B-2B). The average particle size of the core-shell rubber (B-2B) was 0.12 μm. The latex of this core-shell rubber (B-2B) was filtered through a filter with 50 μm openings, then coagulated with calcium acetate, filtered, washed with water, and dried to obtain a core-shell rubber (B-2B).

[0143] (i) Sodium formaldehyde sulfoxylate 0.4 parts Ferrous sulfate 0.00004 parts Disodium ethylenediaminetetraacetate 0.00012 parts (ii) BA 50.9 St 11.6 part AMA 0.56 parts tBH 0.19 parts RS610NA 1.0 part (iii) MMA 35.6 Division MA 1.9 parts tBH 0.056 parts nOM 0.16 parts RS610NA 0.25 part

[0144] [Table 2]

[0145] <Production Example 4: Production of reactive group-containing acrylic polymer (B-1A)> In Production Example 4, a mixture of the following components was placed in a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen gas inlet, and the like. MMA Division 34 BMA 20 copies EA 25th Division MAA Part 21 nOM 0.25 parts LPO 0.4 parts 0.02 parts of methyl methacrylate / methacrylate salt / methacrylate ethyl sulfonate copolymer Sodium sulfate 0.3 parts 145 parts ion-exchanged water

[0146] The atmosphere in the vessel was thoroughly purged with nitrogen gas, and then the mixture was heated to 75°C while stirring, and the polymerization reaction was allowed to proceed in a nitrogen gas stream. After 2 hours, the temperature was raised to 95°C and maintained for an additional 60 minutes to complete the polymerization. The resulting polymer beads were dehydrated and dried to obtain a reactive group-containing acrylic polymer (B-1A). The Tg of the resulting reactive group-containing acrylic resin (B-1A) was 60°C.

[0147] <Production Example 5: Production of reactive group-containing acrylic resin (B-1B)> In Production Example 5, a mixture of the following components was placed in a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen gas inlet, and the like. MMA 80th Division BA 5th Division HPMA 15 copies nOM 0.25 parts LPO 0.4 parts 0.02 parts of methyl methacrylate / methacrylate salt / methacrylate ethyl sulfonate copolymer Sodium sulfate 0.3 parts 145 parts ion-exchanged water The atmosphere in the vessel was thoroughly purged with nitrogen gas, and then the mixture was heated to 75°C while stirring, and the polymerization reaction was allowed to proceed in a nitrogen gas stream. After 2 hours, the temperature was raised to 95°C and maintained for an additional 60 minutes to complete the polymerization. The resulting polymer beads were dehydrated and dried to obtain a reactive group-containing acrylic resin (B-1B). The Tg of the resulting reactive group-containing acrylic resin (B-1B) was 78°C.

[0148] <Production Example 6: Production of thermoplastic polymer (A-2A)> A reaction vessel was charged with 200 parts of nitrogen-substituted ion-exchanged water, 1 part of potassium oleate, and 0.3 parts of potassium persulfate as emulsifiers, followed by 40 parts of MMA, 10 parts of BA, and 0.005 parts of nOM. The mixture was stirred at 65°C under a nitrogen atmosphere for 3 hours to complete the polymerization. Subsequently, a monomer mixture consisting of 48 parts of MMA and 2 parts of BA was added dropwise over 2 hours, and after the completion of the dropwise addition, the mixture was maintained for 2 hours to complete the polymerization. The obtained latex was added to a 0.25% by mass aqueous sulfuric acid solution to cause coagulation, followed by filtration, washing with water, and drying to obtain a thermoplastic polymer (A-2A). The resulting thermoplastic polymer (A-2A) had an Mw of 1,000,000.

[0149] <Production Example 7: Production of acrylic resin composition (A1)> In Production Example 7, 24 parts of the core-shell rubber (A-1B) were blended with 76 parts of VH5001 and 2 parts of (A-2A) as the thermoplastic polymer (A-2). 1 part of L1000, 2.36 parts of LAF70, 0.51 parts of 2020, 0.3 parts of R976, and 0.1 parts of 1076 were added as additives (A-3), and mixed using a Henschel mixer. Next, this was melt-kneaded using a 35 mmφ screw-type twin-screw extruder (L / D=26) under conditions of a cylinder temperature of 200 to 240°C and a die temperature of 240°C, and then pelletized to obtain an acrylic resin composition (A1) for the resin layer (I). The acetone-insoluble content of the acrylic resin composition (A1) was 20%, and the storage modulus of the monolayer film consisting of the layer (I) obtained using the acrylic resin composition (A1) was 728 MPa.

[0150] <Production Examples 8 to 13: Production of acrylic resin compositions (A2) to (A7)> In Production Examples 8 to 13, acrylic resin compositions (A2) to (A7) were obtained in the same manner as in Production Example 7, except that the raw materials used were changed as shown in Table 3.

[0151] [Table 3]

[0152] <Production Example 14: Production of thermoplastic polymer (B-3A)> The thermoplastic polymer (B-3A) used was the same as the thermoplastic polymer (A-2A).

[0153] <Production Examples 15 to 17: Production of acrylic resin compositions (B1) to (B3)> In Production Examples 15 to 17, acrylic resin compositions (B1) to (B3) were obtained in the same manner as in Production Example 7, except that the raw materials used were changed as shown in Table 4.

[0154] [Table 4]

[0155] <Examples 1 to 8: Preparation of laminated film and melamine decorative board> In Example 1, the acrylic resin composition (A1) for the resin layer (I) obtained in Production Example 7 and the acrylic resin composition (B1) for the resin layer (II) obtained in Production Example 14 were dried at 80°C for one day. The acrylic resin composition (B1) was plasticized in a 30 mmφ extruder with a cylinder temperature set to 230°C. The acrylic resin composition (A1) was plasticized in a 40 mmφ extruder equipped with a 400-mesh screen mesh with a cylinder temperature set to 240°C. Next, a 50 μm thick resin laminate film was formed using a two-type, two-layer feedblock die set at 240°C. The thicknesses of resin layers (I) and (II) were 45 μm and 5 μm, respectively. The total light transmittance (TT), haze, yellowing index (YI), and transmittance at 380 nm and 400 nm of the obtained laminate film are summarized in Table 6.

[0156] Furthermore, a melamine substrate (0.1 mm thick, containing Pigment Red 170 / Pigment Orange 13) with a Lightfastness rating of III or higher according to ASTM D4303 was laminated to the resin layer (II) side of this laminate film, and both sides were sandwiched between mirror-finished stainless steel plates and pressed at a temperature of 150°C, a pressure of 3 MPa, and a time of 60 minutes to produce a melamine decorative board. The adhesion results of the resulting melamine decorative board after a water resistance test are shown in Table 6. The endothermic peak temperature of the melamine substrate used was 100°C.

[0157] [Table 5]

[0158] [Table 6]

[0159] In addition, in Examples 2 to 8, laminate films and melamine decorative boards were produced in the same manner as in Example 1, except that the materials shown in Table 5 were used and the thicknesses of the resin layers (I) and (II) were set as shown in Table 5. The evaluation results of the obtained melamine decorative boards are shown in Table 6.

[0160] <Comparative Example 1> A laminate film and a melamine decorative board were produced in the same manner as in Example 1, except that the materials used were as shown in Table 5. The evaluation results of the resulting melamine decorative board are shown in Table 6.

[0161] <Comparative Example 2> A laminate film and a melamine decorative board were produced in the same manner as in Example 1, except that the materials shown in Table 5 were used and laminated with a melamine substrate (thickness 0.1 mm) having a Lightfastness rating of II or less according to ASTM D4303. The evaluation results of the resulting melamine decorative board are shown in Table 6. The endothermic peak temperature of the melamine substrate used was 100°C.

[0162] The above examples and production examples have revealed the following: The laminated films obtained in Examples 1 to 8 have excellent transmittance at a wavelength of 380 nm and excellent weather resistance. They also have excellent moist heat resistance and show little change over time during transportation or storage. Furthermore, they have excellent adhesion to melamine decorative boards, making them highly valuable for industrial use.

[0163] On the other hand, the film obtained in Comparative Example 1 had a transmittance of more than 1% at a wavelength of 380 nm, and when laminated with a substrate layer having a Lightfastness rating of III or higher according to ASTM D4303, the film had poor weather resistance. The film also had poor moist heat resistance. In Comparative Example 2, when the film was laminated with a substrate layer having a rating of II or lower, the film had good weather resistance but poor moist heat resistance.

[0164] Although the present invention has been described above with reference to the embodiments and examples, the present invention is not limited to the above-described embodiments and examples. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

Claims

1. A laminate comprising: an acrylic resin layer including at least a layer made of an acrylic resin composition (A) having a transmittance of less than 1% at a wavelength of 380 nm; and a substrate layer having a Lightfastness rating of III or higher according to ASTM D4303.

2. The laminate according to claim 1 , wherein the acrylic resin layer has a transmittance of less than 1% at a wavelength of 380 nm after 480 hours of metal weather exposure testing.

3. The laminate according to claim 1, wherein the acrylic resin composition (A) contains a core-shell rubber (A-1).

4. The laminate according to claim 1, wherein the acrylic resin composition (A) has an acetone insoluble content of 65% or less.

5. The laminate according to claim 1, wherein the acrylic resin composition (A) has a storage modulus at 100°C of 20 MPa or more.

6. The laminate according to claim 1, wherein the acrylic resin composition (A) contains an ultraviolet absorber, and the molecular weight of the ultraviolet absorber is 400 or more.

7. The laminate according to claim 6, wherein the ultraviolet absorber is a triazine-type ultraviolet absorber and / or a benzotriazole-type ultraviolet absorber.

8. The laminate according to claim 6 , wherein the ultraviolet absorber has a 10% weight loss temperature of 300° C. or higher.

9. 7. The laminate according to claim 6, wherein the content of the ultraviolet absorber in 100 parts by mass of the acrylic resin composition (A) is 0.01 to 10 parts by mass.

10. The laminate according to any one of claims 1 to 9, wherein the acrylic resin composition (A) contains a colorant, and the colorant has a Lightfastness rating of less than III according to ASTM D4303.

11. The laminate according to claim 1 , wherein the acrylic resin layer has a YI of less than 10.

12. The laminate according to any one of claims 1 to 11, wherein the substrate layer (also referred to as substrate) contains an azo pigment other than a condensed azo pigment.

13. The laminate according to any one of claims 1 to 11, wherein the substrate layer (also referred to as substrate) is a melamine substrate.

14. A protective film for a substrate, comprising at least a layer made of an acrylic resin composition (A), and having a lightfastness rating of III or higher according to ASTM D4303, which has a transmittance of less than 1% at a wavelength of 380 nm.

15. The protective film for a substrate according to claim 14, wherein the acrylic resin composition (A) contains a core-shell rubber (A-1).

16. The protective film for a substrate according to claim 14, wherein the acrylic resin composition (A) contains an ultraviolet absorber, and the molecular weight of the ultraviolet absorber is 400 or more.

17. The protective film for a substrate according to claim 16, wherein the ultraviolet absorber is a triazine-type ultraviolet absorber and / or a benzotriazole-type ultraviolet absorber.

18. The protective film for a substrate according to claim 16, wherein the ultraviolet absorber has a 10% weight loss temperature of 300°C or higher.

19. The protective film for a substrate according to claim 16, wherein the content of the ultraviolet absorber per 100 parts by mass of the acrylic resin composition (A) is 0.01 to 10 parts by mass.

20. The protective film for a substrate according to claim 14, wherein the protective film for a substrate is a laminate film comprising a resin layer (I) made of the acrylic resin composition (A) and a resin layer (II) made of an acrylic resin composition (B) containing a reactive group-containing acrylic resin (B-1).

21. A laminate comprising the protective film for a substrate according to any one of claims 14 to 20 and a substrate.

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