JP7245082B2 - ACRYLIC RESIN COMPOSITION FOR FILM AND ACRYLIC RESIN FILM - Google Patents

Description

TECHNICAL FIELD The present invention relates to an acrylic resin composition for films, and an acrylic resin film, laminated film and molded article using the same.

Acrylic resin films made by processing and molding acrylic resin compositions containing rubber-like elastic bodies are used in various applications, taking advantage of their excellent properties such as transparency, hardness, weather resistance, and secondary moldability. is deployed. For example, it can be used for decoration and protection as a substitute for painting by laminating a film on the surface of automobile interior and exterior parts, for decoration and protection of the exterior of products such as mobile electronic devices, personal computers and home appliances, and for antireflection properties. , antiglare and antifouling properties, and decorative and protective applications for building materials, furniture, floor materials, and the like.

When applied to applications such as decoration and protection of surfaces having such planar or three-dimensional shapes, acrylic resin films are used for air pressure molding, vacuum molding, heat press molding, insert/in-mold molding, and three-dimensional lamination. Secondary molding such as molding is performed.

When secondary molding of acrylic resin film or decorative/protective film using this film, or when trimming the film after molding or after lamination to the decorative base material, cracks may occur in the film. These tend to cause poor appearance of the product and reduce the yield of decoration and protection. For this reason, acrylic resin films have excellent crack resistance (hereinafter also referred to as trimming property) that does not cause cracks or breakage during trimming, and less whitening caused by stress during pulling, bending, or cutting (hereinafter referred to as , Bending whitening resistance) are required to be compatible. Moreover, since it is necessary that the surface of the member that has been decorated and protected is not easily damaged during use, the acrylic resin film is also required to have a certain degree of surface hardness.

Furthermore, in recent years, substrates with three-dimensional shapes, such as the surface of automotive interior parts, have been given various surface shapes such as various patterns, patterns, gloss, matte, emboss, etc., and have weather resistance, antireflection, antiglare When it is required to impart various functions such as toughness, antifouling properties, and chemical resistance to sunscreen agents, etc., the surface of the acrylic resin film can be shaped into uneven shapes or various functions can be imparted. In some cases, additives are added to the film, and the film is subjected to surface treatment, lamination of coating layers, and the like. When applying such surface shaping, additives, surface treatment or coating, the acrylic resin film may crack due to the unevenness of the surface, additives, hard and brittle coating, etc. It's easy to get easier. For this reason, acrylic resin films are required to have a further improvement in crack resistance (trimming property) compared to the conventional ones, while maintaining features such as surface hardness and resistance to whitening caused by bending.

Various acrylic resin films have been proposed in order to enable such various decorations and functionalization, but surface hardness, trimming property, and bending whitening resistance are in a trade-off relationship with each other. An acrylic resin film having both at a sufficient level has not yet been found.

In order to provide an acrylic resin film that can be applied to the uses described above, for example, the reduced viscosity of the thermoplastic polymer that constitutes the acrylic resin film, the particle size of the rubber-containing polymer, the rubber content, etc. are specified. A method (Patent Document 1), a method of defining the reduced viscosity of the acrylic polymer and the content of the multilayer structure acrylic polymer (Patent Documents 2 and 3), using rubber particles with different particle sizes together, A method for suppressing cloudiness of a film during high-temperature processing (Patent Document 4) is known. These films are excellent in transparency and film formability.

However, the acrylic resin films described in Patent Documents 1 to 4 have not been developed in consideration of the resistance to whitening caused by bending. For this reason, when the acrylic resin films described in Patent Documents 1 to 4 are laminated on a molded article having a complicated shape, whitening of the film tends to occur due to concentration of stress on corners and the like. When whitening of the film occurs, the commercial value of the molded product provided with the acrylic resin film is significantly impaired. Further, these acrylic resin films contain a large amount of rubber-like elastic material, and if the moldability and crack resistance are sufficiently enhanced, the surface hardness of the film may be lowered.

A methacrylic resin containing a methacrylic acid ester resin (A), a rubber-containing graft copolymer (B), and a rubber-containing graft copolymer (C) as a film having high surface hardness and excellent resistance to whitening on folding. Patent Literature 5 proposes an acrylic resin film obtained by forming the composition (D) into a film.

In Patent Document 5, the amounts of rubber particles constituting the rubber-containing graft copolymer (B) and the rubber-containing graft copolymer particles (C) are optimized, respectively, or the rubber-containing graft copolymer (B) and the rubber It is disclosed that by optimizing the layer structure of the contained graft copolymer particles (C) and the composition of each layer, whitening of the acrylic resin film is suppressed during secondary molding. .

However, in the acrylic resin film described in Patent Document 5, as a result of using a certain amount of the rubber-containing graft copolymer (B) having a large particle size, whitening is still large, and after bending, secondary molding, and after decorative molding, However, it has not been possible to realize a film in which whitening is sufficiently reduced when cutting, etc., and there is a possibility that it will become a problem in the case of decoration that requires dark colors and high transparency. Overall, the amount of rubber-like elastic material used was still small, and the suppression of cracks and breakage during trimming was not always sufficient.

Patent Documents 6 and 9 disclose acrylic resin films using core-shell rubber in which the relationship between the particle size of the core rubber and the concentration of the cross-linking graft crossing agent is specified. However, although whitening does not easily occur with this film, the trimming property is low, and even Example 6 of Patent Document 9, which is considered to have the highest trimming property, was not sufficient in trimming property. Moreover, the content of the graft polymer of the core-shell rubber, which is considered to be soft due to the alkyl acrylate component being larger than that of the matrix resin component, is high. Therefore, since the matrix resin phase is softened, the surface hardness is low, and the pencil hardness of Example 6 of Patent Document 9 was actually 2B.

Patent Document 7 discloses an acrylic resin film in which the concentration of the cross-linking graft crossing agent in the core-shell rubber is low and the amount of the rubber component is blended at a relatively high concentration of 25 to 40% by weight of the total. In this document, since a rubber component with a low degree of cross-linking is blended at a high concentration, the trimming property is excellent, but as a trade-off there is a problem that the surface hardness is remarkably low and whitening is likely to occur.

Patent Document 8 discloses an acrylic resin film containing a methacrylic resin matrix having a low acrylate component content and high heat resistance and 5 to 30% by weight of a core-shell rubber having a relatively large particle size. Although this film has a high surface hardness, it contains a small amount of rubber components and contains hard crosslinked polymethyl methacrylate particles inside the rubber particles, so the trimming property is low. There was also a problem that bleaching was relatively large.

JP-A-8-323934 JP-A-10-279766 JP-A-10-306192 Japanese Patent No. 3835275 Japanese Patent No. 5782521 Japanese Patent No. 4836362 Japanese Patent No. 4809542 Japanese Patent No. 5973658 Japanese Patent No. 4291994

In view of the above-mentioned current situation, the present invention is for a film that can form a film that has both trimming properties (crack resistance during trimming) and surface hardness, and has whitening resistance on bending and less whitening during secondary molding and cutting. An object of the present invention is to provide an acrylic resin composition, and an acrylic resin film, laminated film, and molded article using the same.

As a result of intensive research conducted by the present inventors in order to solve the above problems, a specific composition in which the particle size of the crosslinked elastic layer and the amount of the cross-linking/grafting crossing agent satisfy a specific relationship and the particle size is within a specific range In the presence of the crosslinked elastic layer, a multi-layer structure polymer particle obtained by polymerizing a shell layer having a specific composition so as to satisfy a specific graft ratio is obtained by dividing the ratio of the crosslinked elastic layer with respect to the total resin composition and the shell layer By blending with a thermoplastic resin mainly composed of methyl methacrylate so that the ratio of the acrylic acid alkyl ester falls within a specific range, it is possible to achieve a level of excellent trimming and surface hardness that has not been achieved in the past. found that it is possible to provide an acrylic resin film that also has excellent bending whitening resistance.

That is, the present invention is as follows.
[1] A multilayer structure polymer comprising a crosslinked elastic layer (A) having an average particle size of 70 nm or more and 110 nm or less and one or more shell layers (B) graft-polymerized to the crosslinked elastic layer (A). particles (C), and
An acrylic resin composition (E) for film containing a thermoplastic resin (D) containing 75% by weight or more of methyl methacrylate,
The crosslinked elastic layer (A) comprises 75% by weight or more of an alkyl acrylate (a-1), a crosslinking/grafting crossing agent (H) that is allyl (meth)acrylate, and another monomer (a-2): 0 One or more crosslinked elastomer layers composed of a polymer of monomer components containing not less than 25% by weight and less than 25% by weight,
The shell layer (B) comprises 50% by weight or more of methyl methacrylate (b-1), an acrylic acid alkyl ester (b-2) having a linear or branched alkyl group having 1 to 12 carbon atoms, and other Monomer (b-3) 0% by weight or more and less than 50% by weight, and a polymer of monomer components containing a chain transfer agent and not containing a polyfunctional monomer,
The weight ratio of the crosslinked elastic layer (A) to the total amount of the acrylic resin composition (E) is 15.5% by weight or more and less than 21% by weight,
The weight ratio of the acrylic acid alkyl ester (b-2) to the total amount of the acrylic resin composition (E) is 0.8% by weight or more and less than 3% by weight,
The multi-layer structure polymer particles (C) are acrylic resin compositions for films (E), which satisfy the following 1) to 4).
1) The weight ratio of the crosslinked elastic layer (A) to the total amount of the multilayer structure polymer particles (C) is more than 40% by weight and 60% by weight or less.
2) The average particle diameter d (nm) of the crosslinked elastic layer (A) and the content w of the crosslink/graft crossing agent (H) (wherein the content w is the above-mentioned monomer constituting the crosslinked elastomer layer Among the body components, when the total amount of the components excluding the crosslinking/grafting agent (H) is 100 parts by weight, the ratio of the amount of the crosslinking/grafting agent (H) is expressed by the following relational expression: Fulfill.
0.029d≤w≤0.045d
3) The graft ratio of the shell layer (B) to the crosslinked elastic layer (A) is 51% or more and 80% or less.
4) The weight ratio of the acrylic acid alkyl ester (b-2) to the total amount of the multilayer structure polymer particles (C) is 2% by weight or more and less than 5% by weight.
[2] The acrylic resin composition for film (E) according to [1], wherein the 75 μm-thick film composed of the acrylic resin composition for film (E) satisfies the following 5) to 7).
5) The film is cut with a cutter at 23°C, and no visible cracks are observed at the cut portion formed.
6) Tensile elongation at break at 23°C is 50% or more.
7) The surface hardness of the film is HB or higher in pencil hardness.
[3] The acrylic resin composition for film (E) according to [1] or [2], wherein the 125 μm-thick film composed of the acrylic resin composition for film (E) satisfies the following 8).
8) The number of measurements in the MIT test conforming to JIS P8115 is 50 or more.
[4] The acrylic resin composition for film according to any one of [1] to [3], wherein the film having a thickness of 125 μm composed of the acrylic resin composition for film (E) satisfies the following 9) ( E).
9) When the film is stretched 15% at 23°C, the haze value of the stretched portion is 20% or less.
[5] The acrylic resin composition for film (E) according to [4], wherein the 125 μm-thick film composed of the acrylic resin composition for film (E) satisfies 10) below.
10) When the film is stretched 15% at 23°C, the haze value of the stretched portion is 10% or less.
[6] Multi-layer structure polymer particles (G) containing a crosslinked elastic layer having an average particle diameter of 150 nm or more and 400 nm or less are added in an amount of 0.5 to 2.5 to the total amount of the film acrylic resin composition (E). The acrylic resin composition (E) for film according to any one of [1] to [5], which further contains a weight percent.
[7] An acrylic resin film (F) composed of the film acrylic resin composition (E) according to any one of [1] to [6].
[8] The acrylic resin film (F) according to [7], which is used as an object to which a liquid containing an organic solvent is applied.
[9] A laminated film comprising the acrylic resin film (F) according to [7] or [8] and another film laminated on the film (F).
[10] A molded product body, and the acrylic resin film (F) according to [7] or [8] and/or the laminated film according to [9] laminated on the surface of the molded product body, Molding.

According to the present invention, an acrylic resin composition for a film can form a film having both good trimming property (cracking resistance during trimming) and surface hardness, and with little whitening during secondary molding or cutting and having resistance to whitening on bending. It is possible to provide a product, and an acrylic resin film, a laminated film, and a molded product using the same. Since the acrylic resin film of the present invention has excellent resistance to whitening upon bending, whitening of the film is suppressed even when laminated on the surface of a molded article having a three-dimensional shape.

Embodiments of the present invention are described in detail below.

<Acrylic resin composition (E)>
The acrylic resin composition (E) of the present invention contains at least the multilayer structure polymer particles (C) and the thermoplastic resin (D). According to a preferred embodiment of the present invention, in the acrylic resin composition (E), the multilayer structure polymer particles (C) are dispersed in the matrix of the thermoplastic resin (D).

<Thermoplastic resin (D)>
The thermoplastic resin (D) used in the present invention is an acrylic resin containing 75% by weight or more of methyl methacrylate. The proportion of methyl methacrylate in the thermoplastic resin (D) is preferably 80% by weight or more, more preferably 85% by weight or more, and still more preferably 90% by weight or more, from the viewpoints of hardness and moldability. Also, the upper limit may be 100% by weight, 99% by weight or less, or 98% by weight or less.

In order to improve heat resistance, rigidity, surface hardness, etc., the acrylic resin may be one in which structural units having a specific structure are introduced by copolymerization, functional group modification, modification, or the like. Examples of such a specific structure include, for example, a glutarimide structure as disclosed in JP-A-62-89705, JP-A-02-178310, and International Publication No. 2005/54311, and JP-A-2004-168882. No. and JP-A-2006-171464, etc., a lactone ring structure, as shown in JP-A-2004-307834, etc., obtained by thermally condensing the (meth)acrylic acid unit. Glutaric anhydride structure, maleic anhydride structure as shown in JP-A-5-119217, and N-substituted or unsubstituted maleimide structure as shown in WO 2009/84541, WO 2009/84541 2013/157529, etc., and aromatic vinyl structures such as alpha-methylstyrene in which the aromatic ring is hydrogenated. By introducing these structures into the acrylic resin, the molecular chain can become rigid. As a result, effects such as improved heat resistance, improved surface hardness, reduced heat shrinkage, and improved chemical resistance can be expected.

Examples of monomers other than methyl methacrylate that may be contained in the thermoplastic resin (D) include acrylic acid, acrylic acid derivatives, methacrylic acid, methacrylic acid derivatives, aromatic vinyl derivatives, vinyl cyanide derivatives, or vinylidene halide. These other monomers may be used alone or in combination of two or more.

Examples of acrylic acid derivatives include methyl acrylate, n-butyl acrylate, ethyl acrylate, n-propyl acrylate, isobutyl acrylate, t-butyl acrylate, cyclohexyl acrylate, 2-hydroxyethyl acrylate, and acrylic acid. Examples include acrylates such as 2-phenoxyethyl, benzyl acrylate, 2-(N,N-dimethylamino)ethyl acrylate, and glycidyl acrylate.

Examples of the methacrylic acid derivatives include ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, phenyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, and 2-phenoxy methacrylate. Methacrylic acid esters such as ethyl, isobornyl methacrylate, dicyclopentenyl methacrylate, glycidyl methacrylate, and adamantyl methacrylate.

Examples of the aromatic vinyl derivative include styrene, vinyltoluene, and α-methylstyrene.

Examples of the vinyl cyanide derivative include acrylonitrile and methacrylonitrile.

Examples of the vinylidene halide include vinylidene chloride and vinylidene fluoride.

The method for producing the acrylic resin is not particularly limited, but known polymerization methods such as suspension polymerization method, bulk polymerization method, solution polymerization method, emulsion polymerization method and dispersion polymerization method can be applied. Also, any of known radical polymerization methods, living radical polymerization methods, anionic polymerization methods, and cationic polymerization methods can be applied.

Furthermore, a thermoplastic resin that is at least partially compatible with the acrylic resin may be used in combination with the acrylic resin as long as the object of the present invention is not impaired. Examples of thermoplastic resins that can be used together with acrylic resins include styrene resins, polyvinyl chloride resins, polycarbonate resins, amorphous saturated polyester resins, polyamide resins, phenoxy resins, polyarylate resins, olefin-(meth) acrylic acid derivative resins, cellulose derivatives (cellulose acylate, etc.), vinyl acetate resins, polyvinyl alcohol resins, polyvinyl acetal resins, polylactic acid resins, PHBH resins, and the like.

Styrene-based resins include styrene-acrylonitrile resin, styrene-(meth)acrylic acid resin, styrene-maleic anhydride resin, styrene-N-substituted or unsubstituted maleimide resin, styrene-acrylonitrile-butadiene resin, and styrene-acrylonitrile- acrylic acid ester resin and the like.

Among these thermoplastic resins, styrene resins and polycarbonate resins have excellent compatibility with acrylic resins, and may improve the trimming properties, solvent resistance, low moisture absorption, etc. of acrylic resin films. preferable.

<Multilayer Structure Polymer Particles (C)>
The multilayer structure polymer particle (C) is a polymer having a multilayer structure including a crosslinked elastic layer (A) and one or more shell layers (B) graft-polymerized to the crosslinked elastic layer (A). particles. According to a preferred embodiment of the present invention, the crosslinked elastic layer (A) is particulate, the shell layer (B) is located on the surface side of the particles of the crosslinked elastic layer (A), The multilayer structure polymer particles (C) preferably have a so-called core-shell structure.

In the multilayer structure polymer particles (C) used in the present invention, the weight ratio of the crosslinked elastic layer (A) to the total amount of the multilayer structure polymer particles (C) is more than 40% by weight and 60% by weight or less. is. Within this range, it is possible to provide a film having excellent trimming properties (crack resistance during trimming), surface hardness, and bending whitening resistance, and particularly to improve surface hardness. It is preferably 41% by weight or more and 58% by weight or less, more preferably 45% by weight or more and 55% by weight or less. When the weight ratio of the crosslinked elastic layer (A) is 40% by weight or less, the compounding amount of the multilayer structure polymer particles (C) in the acrylic resin composition (E) for maintaining a certain trimming property increases, Increased melt viscosity and melt elasticity may reduce film appearance quality, dimensional accuracy, and surface hardness. If the weight ratio of the crosslinked elastic body (A) exceeds 60% by weight, it becomes difficult to maintain the grafting rate described below within a certain range, and the interface between the multilayer structure polymer particles (C) and the thermoplastic resin (D) is disturbed. Insufficient affinity may lead to a decrease in trimming properties and an increase in appearance defects such as fish eyes in the acrylic resin film due to poor dispersion of the multilayer structure polymer particles (C). As will be described later, the crosslinked elastic layer (A) may contain concentric spherical hard or semi-hard core particles in its particles. When the crosslinked elastic layer (A) contains such core particles, the weight of the crosslinked elastic layer (A) includes the weight of the core particles.

Further, when blending the multilayer structure polymer particles (C) into the acrylic resin composition (E), the weight ratio of the crosslinked elastic layer (A) to the total weight of the acrylic resin composition (E) was 15.5%. % or more and less than 21% by weight. Within this range, it is possible to provide a film having excellent trimming properties, surface hardness, and bending whitening resistance. It is preferably 17% by weight or more and 20.9% by weight or less, more preferably 18% by weight or more and 20.8% by weight or less. If the weight ratio of the crosslinked elastic layer (A) to the total amount of the acrylic resin composition (E) is less than 15.5% by weight, trimming properties may deteriorate and resistance to whitening on bending may deteriorate. Moreover, when it exceeds 21 weight%, surface hardness may fall.

The crosslinked elastic layer (A) comprises 75% by weight or more of an alkyl acrylate (a-1), a crosslinking/grafting crossing agent (H) that is allyl (meth)acrylate, and another monomer (a-2): 0 It includes a crosslinked elastomer layer composed of a polymer of a monomer component containing not less than 25% by weight and less than 25% by weight. The crosslinked elastomer layer may consist of only one layer, or may consist of two or more layers. As will be described later, the particles of the crosslinked elastic layer (A) may contain core particles inside.

The monomer components of the crosslinked elastomer layer may be mixed together and polymerized in one step. In addition, for the purpose of adjusting the toughness, whitening resistance, etc. of the film, polymerization may be carried out in two or more stages as appropriate, and the composition of the monomer components in each stage may be the same. and may be different from each other.

As the alkyl acrylate (a-1), an alkyl ester of acrylic acid having 1 to 22 carbon atoms is particularly preferably used because it has excellent polymerizability, is inexpensive, and gives a polymer with a low glass transition temperature. be able to.

Specific examples of preferred monomers include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isobornyl acrylate, and acrylic acid. Examples include cyclohexyl, dodecyl acrylate, stearyl acrylate, heptadecyl acrylate, octadecyl acrylate and the like. These may be used alone or in combination of two or more.

The amount of alkyl acrylate (a-1) is 75% by weight or more based on 100% by weight of the monomer component of the crosslinked elastomer layer. When the alkyl acrylate (a-1) is used within this range, the impact resistance of the acrylic resin film and elongation at breakage are good, and excellent trimming properties can be achieved. It is preferably 80% by weight or more, more preferably 85% by weight or more. The upper limit may be 100% or less, and is set according to the amounts of the cross-linking/grafting agent (H) and the other monomer (a-2).

Monomers (a-2) other than alkyl acrylate (a-1) include, for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and t-butyl methacrylate. , phenyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, phenoxyethyl methacrylate, isobornyl methacrylate, methacrylic acid esters such as dicyclopentenyl methacrylate, vinyl halides such as vinyl chloride and vinyl bromide, acrylonitrile, methacrylonitrile Vinyl esters such as vinyl cyanide, vinyl formate, vinyl acetate, vinyl propionate, etc., aromatic vinyl derivatives such as styrene, vinyl toluene, α-methylstyrene, vinylidene halides such as vinylidene chloride, vinylidene fluoride, acrylic acid , acrylic acid such as sodium acrylate, calcium acrylate, and its salts, β-hydroxyethyl acrylate, phenoxyethyl acrylate, benzyl acrylate, dimethylaminoethyl acrylate, glycidyl acrylate, acrylamide, N-methylol Acrylic acid derivatives such as acrylamide, methacrylic acid, methacrylic acid such as sodium methacrylate, calcium methacrylate, and salts thereof, methacrylic acid derivatives such as methacrylamide, β-hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, and glycidyl methacrylate , maleic anhydride, N-alkylmaleimide, N-phenylmaleimide and other maleic acid derivatives. These may be used alone or in combination of two or more. Among these, methacrylic acid esters and aromatic vinyl derivatives are particularly preferred from the viewpoint of weather resistance and transparency.

The amount of the other monomer (a-2) is set according to the amounts of the alkyl acrylate (a-1) and the cross-linking/grafting crossing agent (H), and is 0 at 100% by weight of the monomer component of the cross-linked elastomer layer. % by weight or more and less than 25% by weight. When the amount of the other monomer (a-2) used is large, the impact resistance of the acrylic resin film tends to decrease, the elongation at tensile breakage decreases, and sufficient trimming properties may not be achieved. It is preferably 1% by weight or more and less than 30% by weight, more preferably 5% by weight or more and less than 20% by weight. The other monomer (a-2) is an optional monomer and may not be used.

In the crosslinked elastomer layer, allyl acrylate and/or allyl methacrylate (both are collectively referred to as allyl (meth)acrylate) is used as a crosslink/graft crossing agent (H). This forms a crosslinked structure and forms graft points for graft polymerization of the shell layer (B) to the crosslinked elastic layer (A). The amount of allyl (meth)acrylate is preferably 0.1% by weight or more and 10% by weight or less, more preferably 0.5% by weight or more and 5% by weight or less, based on 100% by weight of the monomer component of the crosslinked elastomer layer. % by weight or more and 4% by weight or less is more preferable. When the amount of allyl (meth)acrylate used is within the above range, a suitable degree of cross-linking of the cross-linked elastic layer (A) and a suitable graft ratio of the shell layer (B) can be achieved, resulting in excellent trimming properties and bending resistance. Whitening property can be achieved, and it is also preferable from the viewpoint of the fluidity of the resin composition during molding.

However, in the crosslinked elastomer layer, polyfunctional monomers other than allyl (meth)acrylate may be used in combination. Examples of such polyfunctional monomers include triallyl cyanurate and triallyl isocyanate. Nurate, diallyl phthalate, diallyl maleate, divinyl adipate, divinylbenzene, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, polyethylene glycol dimethacrylate, and dipropylene Glycol dimethacrylate and the like can be mentioned.

In the crosslinked elastic layer (A), the amount of allyl (meth)acrylate in the crosslinked elastic layer (A) is adjusted to increase the graft coverage efficiency of the shell layer (B), which will be described later. A) may be changed inside the particle and near the surface. Specifically, as disclosed in Japanese Patent No. 1460364, Japanese Patent No. 1786959, etc., the content of allyl (meth)acrylate in the vicinity of the surface of the particles of the crosslinked elastic layer (A) is By making the amount larger than the inside of the particle, the coating of the crosslinked elastic layer (A) with the shell layer (B) is improved, the dispersibility in the thermoplastic resin (D) is improved, and the multilayer structure polymer particles ( It is possible to suppress deterioration of the trimming property due to peeling at the interface between C) and the thermoplastic resin (D). Furthermore, since a relatively small amount of the shell layer (B) provides a sufficient coating, the total amount of the multilayer structure polymer particles (C) can be reduced, and the melt processability of the acrylic resin film due to the decrease in melt viscosity. , improvement of film processing accuracy, improvement of surface hardness, etc. can be expected. In this case, the content w of the cross-linking/grafting cross-linking agent (H), which will be described later, is the total amount of the components excluding the cross-linking/grafting cross-linking agent (H) among all the monomer components constituting the crosslinked elastomer layer. The ratio of the total amount of the cross-linking/grafting crossing agent (H) is shown in parts by weight.

For the monomer component of the crosslinked elastomer layer, control of the molecular weight and crosslink density of the polymer constituting the crosslinked elastomer layer, and thermal stability related to the amount of double bond ends of the polymer due to disproportionation termination of the polymerization reaction A chain transfer agent may be added for the purpose of controlling the The chain transfer agent is selected and used from those commonly used in radical polymerization. Examples of chain transfer agents include monofunctional or polyfunctional mercaptan compounds having 2 to 20 carbon atoms such as n-octylmercaptan, n-dodecylmercaptan, and t-dodecylmercaptan, mercapto acids, thiophenol, and tetrachloride. Carbon or mixtures thereof and the like are preferred. The amount of the chain transfer agent used is preferably 0 parts by weight or more and 0.1 parts by weight or less, more preferably 0 parts by weight or more and 0.1 part by weight or more per 100 parts by weight of the total amount of the monomer components of the crosslinked elastomer layer. 2 parts by weight or less. However, the chain transfer agent is an optional component in the crosslinked elastomer layer and may not be used.

The particles of the crosslinked elastic layer (A) may consist of a single layer made of a crosslinked elastomer, or may consist of two or more layers made of a crosslinked elastomer. It may have a multi-layer structure of concentric spheres with a core particle of rigid or semi-rigid polymer inside. Examples of such core particles include hard crosslinked methacrylic resin particles as disclosed in JP-B-55-27576, and methyl methacrylate-acrylate-styrene particles as disclosed in JP-A-4-270751. Examples include semi-rigid crosslinked particles, crosslinked rubber particles having a high degree of crosslinking, and the like. In some cases, improvement in transparency, color tone, etc. can be expected by providing such core particles.

Monomers constituting the hard or semi-rigid polymer of the core particles include methacrylate esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, benzyl methacrylate and phenoxyethyl methacrylate, methyl acrylate, acrylic Alkyl acrylates such as ethyl acetate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate and n-octyl acrylate, aromatics such as styrene and α-methylstyrene Examples include vinyl, vinyl cyanide such as acrylonitrile, maleic acid derivatives such as maleic anhydride and maleimides, and polyfunctional monomers having two or more non-conjugated double bonds per molecule.

Among these, methyl methacrylate, butyl methacrylate, butyl acrylate, ethyl acrylate, styrene, acrylonitrile and the like are particularly preferred. As the polyfunctional monomer, allyl (meth)acrylate and the compounds described above for the crosslinked elastomer layer can be used. Furthermore, during the polymerization of a hard or semi-hard crosslinked resin layer, in addition to these monomers, a chain transfer agent is added for the purpose of controlling the thermal stability, etc. by controlling the crosslink density and reducing the double bond ends of the polymer. They may be used together. As the chain transfer agent, the same chain transfer agent as used in the polymerization of the crosslinked elastomer layer can be used. The amount of the chain transfer agent used is preferably 0 parts by weight or more and 2 parts by weight or less, more preferably 0 parts by weight or more and 0.5 parts by weight or less with respect to 100 parts by weight of the total amount of the rigid or semi-rigid crosslinked resin layer. be.

In the present invention, the average particle size of the crosslinked elastic layer (A) is 70 nm or more and 110 nm or less. Within this range, it is possible to provide a film having excellent trimming properties, surface hardness, and bending whitening resistance. It is preferably 75 nm or more and 100 nm or less. Here, the average particle size of the crosslinked elastic layer (A) is measured using a laser diffraction particle size distribution measuring device such as Microtrac particle size distribution measuring device MT3000 manufactured by Nikkiso Co., Ltd., and using a light scattering method in a latex state. can be measured

In the present invention, the average particle size of the crosslinked elastic layer (A) and the content of the crosslink/graft crossing agent (H) greatly affect the trimming properties, surface hardness, and bending whitening resistance of the film. To achieve the effect of the invention, it is desirable to set both values so as to satisfy a specific relationship. Specifically, the average particle diameter d (nm) of the crosslinked elastic layer (A) and the content w of the crosslink/graft crossing agent (H) are expressed by the following relational expression:
0.029d≤w≤0.045d
The average particle size of the crosslinked elastic layer (A) and the content of the crosslink/graft crossing agent (H) are set so as to satisfy the above. Within the range of the above relational expression, it is possible to realize a film having excellent trimming properties, surface hardness, and bending whitening resistance. If w is less than 0.029d, the resistance to whitening on bending may deteriorate. On the other hand, when w exceeds 0.045d, the trimming property may deteriorate. However, the content w of the cross-linking/grafting crossing agent (H) was set to 100 parts by weight of the total amount of components excluding the cross-linking/grafting crossing agent (H) among the monomer components constituting the crosslinked elastomer layer. It shows the ratio of the amount of the cross-linking/grafting crossing agent (H) at the time.

<Shell layer (B)>
The shell layer (B) is formed by graft-polymerizing a monomer component for the shell layer in the presence of the particles of the crosslinked elastic layer (A), thereby stacking the shell layer (B) on the crosslinked elastic layer (A). It can be formed by grafting coalescence. In the above graft polymerization, some polymer components (also referred to as free polymers) that are not graft-bonded to the crosslinked elastic layer (A) may occur. is included in

The shell layer (B) occupies a portion of the multilayer structure polymer particles (C) other than the portion occupied by the crosslinked elastic layer (A). The weight ratio of the shell layer (B) to the total weight of the multilayer structure polymer particles (C) is 40% by weight or more and less than 60% by weight. If the weight ratio of the shell layer (B) is less than 40% by weight, it will be difficult to maintain the graft ratio described later within a certain range, and the dispersibility of the multilayer structure polymer particles (C) in the acrylic resin film (F) will be affected. may decrease, resulting in appearance defects such as fisheyes in the film, and may decrease the trimming properties and bending whitening resistance. When the weight ratio of the shell layer (B) is 60% by weight or more, the graft crossing sites of the graft polymer tend to penetrate inside the particles of the crosslinked elastic layer (A), and the crosslinked elastic layer becomes hard. Trimming performance may deteriorate. In addition, in order to maintain a constant content of the crosslinked elastic layer (A) in the acrylic resin film (F), the amount of the multi-layer structure polymer particles (C) blended in the acrylic resin film (F) is increased. This may increase the melt viscosity and melt elasticity of the resin composition (E), making it difficult to melt-form an acrylic resin film having excellent dimensional accuracy and appearance quality. Also, when the ratio of the shell layer (B), which is slightly softer than the thermoplastic resin (D), in the acrylic resin film increases, the surface hardness of the film tends to decrease.

The shell layer (B) comprises 50% by weight or more of methyl methacrylate (b-1), an acrylic acid alkyl ester (b-2) having a linear or branched alkyl group having 1 to 12 carbon atoms, and other It is composed of a polymer of a monomer component containing 0% by weight or more and less than 50% by weight of monomer (b-3) and a chain transfer agent and containing no polyfunctional monomer. The shell layer (B) may consist of only one layer, or may consist of two or more layers.

The amount of methyl methacrylate (b-1) is 50% by weight or more based on 100% by weight of the monomer component of the shell layer (B). When methyl methacrylate (b-1) is used in this range, it has excellent compatibility with the thermoplastic resin (D), can improve the transparency of the film, and has excellent trimming properties, surface hardness, and resistance. It is possible to realize a film having whitening property on bending. It is preferably 60% by weight or more, more preferably 70% by weight or more, still more preferably 80% by weight or more, and particularly preferably 90% by weight or more. The upper limit may be less than 100% by weight, and is set according to the amounts of the alkyl acrylate (b-2) and other monomer (b-3) described later, but is preferably 99% by weight or less. It is more preferably 97% by weight or less, still more preferably 95% by weight or less.

Examples of alkyl acrylates (b-2) having a linear or branched alkyl group having 1 to 12 carbon atoms include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, Examples include 2-ethylhexyl acrylate, n-octyl acrylate and dodecyl acrylate. These may be used alone or in combination of two or more. The number of carbon atoms in the alkyl is preferably 1-8, more preferably 1-6, even more preferably 1-4.

In the present invention, the weight ratio of the acrylic acid alkyl ester (b-2) to the total amount of the multilayer structure polymer particles (C), and the acrylic acid alkyl ester (b-2) to the total amount of the acrylic resin composition (E) ) are set within specific ranges. The former is 2% by weight or more and less than 5% by weight, preferably 2.1% by weight or more and 4.5% by weight or less, more preferably 2.2% by weight or more and 4.0% by weight or less. The latter is 0.8 wt% or more and less than 3 wt%, preferably 0.8 wt% or more and 2.5 wt% or less, more preferably 0.8 wt% or more and 2.0 wt% or less, More preferably, it is 0.8% by weight or more and 1.5% by weight or less. By setting the amount of alkyl acrylate (b-2) used, the amount of shell layer (B) used, and the amount of multilayer structure polymer particles (C) used so as to satisfy the above ranges, , a film having excellent trimming properties, surface hardness, and bending whitening resistance can be realized. If the former is less than 2% by weight or the latter is less than 0.8% by weight, trimming properties and resistance to whitening on bending may deteriorate. If the former is 5% by weight or more or the latter is 3% by weight or more, the surface hardness of the film may decrease.

Other monomers (b-3) other than methyl methacrylate (b-1) and alkyl acrylate (b-2) include, for example, methacrylates other than methyl methacrylate, and linear chains having 1 to 12 carbon atoms. Acrylic acid esters other than acrylic acid alkyl esters having a linear or branched alkyl group, aromatic vinyl compounds such as styrene and its nucleus-substituted derivatives, unsaturated nitriles such as acrylonitrile, (meth)acrylic acid and its derivatives, Examples include N-substituted maleimides, maleic anhydride, (meth)acrylamide, and the like.

The amount of the other monomer (b-3) is set according to the amounts of the methyl methacrylate (b-1) and the alkyl acrylate (b-2), and the monomer components of the shell layer (B) It is 0% by weight or more and less than 50% by weight in 100% by weight. It is more preferably 0% by weight or more and less than 30% by weight, and still more preferably 0% by weight or more and less than 10% by weight. The other monomer (b-3) is an optional monomer and may not be used.

Further, as another monomer (b-3), a monomer that is a reactive ultraviolet absorber may be used. That is, the shell layer (B) may contain structural units derived from a reactive ultraviolet absorber. Thereby, an acrylic resin film having good weather resistance and chemical resistance can be obtained.

As the reactive UV absorber, a known reactive UV absorber can be used without particular limitation, but for example, 2-(2'-hydroxy-5'-methacryloyloxyethylphenyl)-2H-benzotriazole kind can be used. Specifically, 2-(2′-hydroxy-5′-acryloyloxyethylphenyl)-2H-benzotriazole, 2-(2′-hydroxy-5′-methacryloyloxyethylphenyl-2H-benzotriazole, 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl)-5-chloro-2H-benzotriazole, 2-(2′-hydroxy-5′-methacryloyloxypropylphenyl)-2H-benzotriazole, 2-(2 '-hydroxy-5'-methacryloyloxyethyl-3'-t-butylphenyl)-2H-benzotriazole, etc. More preferably, 2-(2'-hydroxy-5'- methacryloyloxyethylphenyl)-2H-benzotriazole.

When a reactive ultraviolet absorber is used, the amount of the reactive ultraviolet absorber is preferably 0.01% by weight or more and 5% by weight or less based on 100% by weight of the monomer component of the shell layer (B), and 0.1% by weight. % or more and 3% by weight or less is more preferable.

A monomer component of the shell layer (B) contains a chain transfer agent. By using a chain transfer agent in the shell layer (B), the molecular weight of the polymer constituting the shell layer (B), the graft ratio described later, and the generation of free polymer not bonded to the crosslinked elastic layer (A) Amount etc. can be controlled. As the chain transfer agent in the shell layer (B), the same chain transfer agents as those described above for the crosslinked elastomer layer can be used. Particularly preferred are n-octyl mercaptan and the like.

The monomer component of the shell layer (B) does not contain a polyfunctional monomer containing allyl (meth)acrylate, and therefore the shell layer (B) does not substantially have a crosslinked structure. is. Here, the polyfunctional monomer has two or more carbon-carbon unsaturated bonds per molecule that can be copolymerized with methyl methacrylate (b-1) or alkyl acrylate (b-2). Refers to a compound, specifically those mentioned above for the crosslinked elastomeric layer.

In the present invention, the graft ratio of the shell layer (B) to the crosslinked elastic layer (A) is 51% or more and 80% or less. The graft ratio indicates the ratio of the weight of the polymer component of the shell layer (B) bonded to the crosslinked elastic layer (A) to the weight of the crosslinked elastic layer (A). When the graft ratio is within the above range, it is possible to realize a film having excellent trimming properties, surface hardness, and bending whitening resistance. It is preferably 55% or more and 75% or less, more preferably 60% or more and 70% or less. The graft ratio is determined by the type and amount of the cross-linking agent and graft crossing agent used in the cross-linked elastic layer (A), the number of parts of the shell layer (B), the polymerization temperature, the concentration of the monomers constituting the shell layer during polymerization, It can be adjusted by selecting the type and amount of chain transfer agent used in the shell layer. If the graft ratio is less than 51%, the interfacial adhesion between the multilayer structure polymer particles (C) and the thermoplastic resin (D) may become weak, and the multilayer structure polymer particles in the acrylic resin film (F) ( There is a possibility that the dispersibility of C) will be lowered, causing appearance defects such as fisheyes in the film, and that the trimming properties and bending whitening resistance will be lowered. If the graft ratio exceeds 80%, the graft site of the graft polymer tends to enter the inside of the particles of the crosslinked elastic layer (A), and the crosslinked elastic layer becomes hard, which may reduce trimming properties. . The graft ratio can be measured by a known method, for example, by separating the multi-layer structure polymer particles into a crosslinked elastic layer+grafted polymer portion and a non-grafted polymer portion using an organic solvent.

<Method for producing multilayer structure polymer particles (C)>
The method for producing the multilayer structure polymer particles (C) is not particularly limited, and a known emulsion polymerization method, miniemulsion polymerization method, suspension polymerization method, bulk polymerization method, solution polymerization method, or dispersion polymerization method can be applied. be. The emulsion polymerization method is particularly preferred because it has a wide adjustment range for the resin structure.

Known initiators such as organic peroxides, inorganic peroxides and azo compounds can be used as the initiator used in the emulsion polymerization of the multilayer structure polymer particles (C). Specifically, t-butyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, succinic acid peroxide, t-butyl peroxymaleate, cumene hydroperoxide, Organic peroxides such as benzoyl peroxide and lauroyl peroxide; inorganic peroxides such as potassium persulfate, sodium persulfate and ammonium persulfate; and azo compounds such as azobisisobutyronitrile. These may be used alone or in combination of two or more.

These initiators may be used as thermal decomposition type radical polymerization initiators, or these initiators may be added to sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, hydroxyacetone acid, and the like. It may also be used as a redox initiator system in combination with a reducing agent and a catalyst such as ferrous sulfate or a complex of ferrous sulfate and ethylenediaminetetraacetate-2-sodium.

Among them, from the viewpoint of polymerization stability and particle size control, inorganic peroxides such as potassium persulfate, sodium persulfate and ammonium persulfate are used, or t-butyl hydroperoxide, cumene hydroperoxide and the like are used. It is more preferable to use a redox type initiator system using an organic peroxide of .

The above inorganic peroxide or organic peroxide is added by a known method such as a method of adding as it is to the polymerization system, a method of adding by mixing with a monomer, or a method of adding after dispersing in an aqueous emulsifier solution. can do. From the viewpoint of the transparency of the acrylic resin film, the method of adding by mixing with the monomer and the method of adding by dispersing in an emulsifier aqueous solution are preferable.

The surfactant used for emulsion polymerization of the multilayer structure polymer particles (C)) is not particularly limited. A wide range of known surfactants can be used for emulsion polymerization. Preferred surfactants include, for example, oleic acid, tallow fatty acid, N-laurylsarcosinate, alkylethercarboxylic acid, alkylsulfonic acid, alkylethersulfonic acid, alkylbenzenesulfonic acid, dialkylsulfosuccinic acid, alkylsulfuric acid, alkyl Anionic surfactants such as sodium, potassium, and ammonium salts of acid group-containing compounds such as ether sulfuric acid, fatty acids, alkyl phosphates, alkyl ether phosphates, alkyl phenyl ether phosphates, surfactins, alkylphenols, Examples include nonionic surfactants such as reaction products of aliphatic alcohols with propylene oxide and ethylene oxide. Among these surfactants, anionic surfactants having excellent emulsion stabilizing ability are preferred, and sulfonic acid-based, sulfate monoester-based and phosphoric acid-based surfactants are particularly preferred. These surfactants may be used alone or in combination of two or more.

From the latex of the multilayer structure polymer particles (C) obtained by emulsion polymerization, the multilayer structure polymer particles (C) can be separated and recovered by a known method. For example, the multi-layered structure polymer particles (C) can be recovered by adding a water-soluble electrolyte to the latex and solidifying it, followed by washing and drying the solid content. Alternatively, the multi-layer structure polymer particles (C) can be separated by spray drying, freeze-drying, or the like on the latex, and then recovered after appropriate washing and drying.

More preferably, for the purpose of reducing appearance defects and internal foreign substances in the acrylic resin film, prior to separation and recovery of the multilayer structure polymer particles (C), the latex of the multilayer structure polymer particles (C) is filtered or meshed in advance. Filtration removes substances that cause foreign matter and defects, such as environmental foreign matter and polymerized scale.

For example, the opening of the filter or mesh may be two times or more larger than the average particle size of the multilayer structure polymer particles (C). As filters and meshes, known filters and meshes used for filtering liquid media can be used. The type, mesh size, filtration accuracy, filtration capacity, etc. of the filter or mesh are appropriately selected according to the target application, the type, size and amount of foreign matter to be removed, and the productivity, but preferably the mesh of the filter is The aperture or filtration accuracy is 0.5 μm or more and 100 μm or less, more preferably 1 μm or more and 50 μm or less.

<Multilayer Structure Polymer Particles (G)>
The acrylic resin composition (E) of the present invention contains, in addition to the multilayer structure polymer particles (C), a small amount of multilayer structure polymer particles (G) containing a crosslinked elastic layer having a relatively large particle size. There may be. The multi-layer structure polymer particles (G) are excellent in the effect of imparting impact resistance and crack resistance to the acrylic resin. It is possible to improve the balance between the properties and the surface hardness.

The multilayer structure polymer particles (G) contain a crosslinked elastic layer containing at least one crosslinked elastomer layer, like the multilayer structure polymer particles (C), but the average particle diameter of the crosslinked elastic layer is 150 nm or more. It differs from the multilayer structure polymer particles (C) in that it is 400 nm or less. The average particle size is more preferably 200 nm or more and 350 nm or less.

The multilayer structure polymer particles (G) typically include a shell layer positioned closer to the surface than the crosslinked elastic layer, similarly to the multilayer structure polymer particles (C). That is, the multilayer structure polymer particles (G) preferably contain a crosslinked elastic layer and a shell layer.

The multi-layer structure polymer particles (G) have an average particle size of the crosslinked elastic layer larger than that of the multi-layer structure polymer particles (C), and have the same monomer composition as the multi-layer structure polymer particles (C). Except that there is no limitation on the ratio, the raw materials, production method, etc. are generally the same as those of the multilayer structure polymer particles (C). Particularly preferably, the crosslinked elastic layer of the multilayer structure polymer particle (G) has a concentric spherical multilayer structure comprising a core particle made of a hard or semi-rigid polymer inside the crosslinked elastomer layer. Such core particles include, for example, hard crosslinked methacrylic resin particles as shown in JP-B-55-27576, and methacrylic resin particles as shown in JP-A-4-270751 and WO 2014/41803. Examples thereof include crosslinked particles having a semi-rigid layer made of a methyl acid-acrylic acid ester-styrene copolymer or the like. By introducing such a core particle, the multilayer structure polymer particles (G) having a larger particle diameter than the multilayer structure polymer particles (C) can be improved in transparency, resistance to whitening on bending, resistance to cracking, and the like. can be done.

The blending ratio of the multilayer structure polymer particles (G) can be appropriately set by those skilled in the art, but it is a ratio of 0.5 to 2.5% by weight with respect to the total amount of the acrylic resin composition (E). is preferred. When the blending ratio is within this range, it is possible to enjoy the effects of blending the multi-layered structure polymer particles (G) and achieve good resistance to whitening on bending. More preferably, it is in the range of 1.0 to 2.0% by weight. If the blending ratio exceeds 2.5% by weight, the trimming property is improved, but the bending resistance to whitening may be significantly deteriorated.

Conventionally known additives used for acrylic resin films can be added to the acrylic resin composition of the present invention as long as the effects of the present invention are not impaired. Such additives include antioxidants, ultraviolet absorbers, light stabilizers, light diffusing agents, matting agents, lubricants, colorants such as pigments and dyes, antiblocking agents made of organic crosslinked particles and inorganic particles, Infrared reflective agents, plasticizers, antistatic agents, etc. made of metals and metal oxides can be mentioned. Additives are not limited to these. These additives can be used in any amount depending on the type of additive, as long as the objects of the present invention are not impaired.

<Acrylic resin film (F)>
The acrylic resin film (F) of the present invention is composed of the acrylic resin composition (E) described above, and has excellent trimming properties (crack resistance during trimming), surface hardness, and secondary molding. It also has resistance to whitening when bending and cutting.

The haze value of the acrylic resin film measured according to JIS K6174 is preferably 1.3% or less, more preferably 1.1% or less, even more preferably 0.8% or less, and particularly preferably 0.6% or less. .

The acrylic resin film of the present invention preferably satisfies any or all of the following requirements 5) to 9) when the thickness of the film is 75 μm or 125 μm.

5) A film having a thickness of 75 μm is cut with a cutter at 23° C., and no visible cracks are observed at the cut portion formed. Specific test methods are described in Examples. It corresponds to "5+" or "5" of the criteria described later. This physical property indicates excellent trimming properties (crack resistance during trimming).

6) A film having a thickness of 75 μm has a tensile elongation at break at 23° C. of 50% or more. It is preferably 53% or more, more preferably 55% or more, still more preferably 58% or more, still more preferably 60% or more, particularly preferably 63% or more, and most preferably 65% or more. The elongation at break is a value measured using a Tensilon tensile tester under conditions of a chuck distance of 40 mm and a tensile speed of 200 mm/min. Details of the test method are described in Examples.

7) The surface hardness of the film having a thickness of 75 μm is HB or higher as a pencil hardness measured according to JIS K5600-5-4. The pencil hardness may be HB or a hardness exceeding HB (such as H). The details of the test method are described in the Examples section.

8) A film having a thickness of 125 μm is measured 50 times or more in the MIT test based on JIS P8115. It is preferably 60 times or more, more preferably 65 times or more, still more preferably 70 times or more, and particularly preferably 75 times or more. Details of the test method are described in "MIT Test" in Examples.

9) The haze value of the stretched portion is 20% or less when a film having a thickness of 125 µm is stretched 15% at 23°C. It is preferably 15% or less, more preferably 10% or less. Details of the test method are described in "Haze value after stretching at room temperature (bending whitening resistance)" in Examples. This physical property is an index showing excellent bending whitening resistance.

Regarding the 5) trimming property, 6) tensile elongation at break, 7) surface hardness, and 8) the number of measurements in the MIT test, the crosslinked elastic layer (A ) or the ratio of the alkyl acrylate (b-2), the amount of the alkyl acrylate (b-2) in the multilayer structure polymer particles (C), the shell layer ( The graft ratio of B) is greatly affected, and by setting these numerical values within the ranges specified in the present invention, the requirements of 5), 6), 7), and 8) are satisfied. it becomes possible to

Regarding the above 9) haze value after stretching at room temperature, the relational expression between the average particle size of the crosslinked elastic layer (A) and the content of the crosslink/graft crossing agent (H), the shell layer ( The graft ratio of B) is greatly affected, and by setting these numerical values within the ranges specified in the present invention, it is possible to satisfy the requirement of 9) above. In addition to the above, by controlling the proportion of the crosslinked elastic layer (A) in the acrylic resin composition (E) as a whole, it becomes possible to lower the haze value after stretching at room temperature.

<Method for producing acrylic resin film (F)>
The acrylic resin film (F) can be produced by a known processing method. Specific examples of known processing methods include melt processing, calendar molding, press molding, and solvent casting. The melt processing method includes an inflation method, a T-die extrusion method, and the like. In the solvent casting method, after the acrylic resin composition is dissolved and dispersed in a solvent, the resulting dispersion (dope) is poured onto a belt-like substrate in the form of a film. Next, an acrylic resin film is obtained by volatilizing the solvent from the drooled film-like dope.

Among these methods, a solvent-free melt processing method, particularly a T-die extrusion method, is preferred. According to the melt processing method, there are few restrictions on the thickness of the film to be manufactured, a film with excellent surface properties can be manufactured with high productivity, and the load on the natural environment and working environment due to solvents and manufacturing costs are reduced. be able to.

When the acrylic resin composition is formed into a film by a melt processing method or a solvent casting method, from the viewpoint of improving the appearance quality of the acrylic resin film, filtration using a filter or mesh is used to remove external defects and internal defects of the acrylic resin film. It is preferable to remove environmental foreign matter, polymerization scale, degraded resin, and the like in the acrylic resin composition that cause foreign matter and the like.

When producing a film by melt processing, filtration is performed at any one or more times during the preparation of the acrylic resin composition by melt mixing, during pelletization of the molten acrylic resin composition, and during the film formation process using a T-die. It can be carried out. In the solvent casting method, after mixing the multilayer structure polymer particles (C), the thermoplastic resin (D) and other components with a solvent, the mixture may be filtered before cast film formation.

As such a filter or mesh, as long as the filter or mesh has heat resistance and durability according to the melt processing conditions, and resistance to casting solvents, dopes, etc., known filters and meshes can be used without particular limitations. can.

When producing an acrylic resin film by melt processing, in order to obtain a particularly high-quality acrylic resin film, it is necessary to use a molten resin that has a large filtration capacity and causes generation of resin degradation products and cross-linked products that impair the quality of the film. Filters with low retention are preferred. For example, it is preferable to use a leaf disk type filter or a pleated type filter in terms of filtration efficiency and productivity.

When the acrylic resin film is produced by the T-die extrusion method, in order to improve the thickness accuracy of the film, for example, the film thickness distribution in the TD direction (perpendicular to the extrusion direction) of the extruded film is measured online. An automatic die device can be used that automatically adjusts the T-die lip clearance during film extrusion on this basis. Applying an automatic die with an appropriate control method may improve the thickness accuracy of the acrylic resin film.

In the production of an acrylic resin film, if necessary, when molding the film, both sides of the molten film are brought into contact with (sandwiched between) cooling rolls or cooling belts at the same time to obtain a film with better surface properties. be able to. In this case, the molten film is preferably brought into contact simultaneously with a roll or metal belt maintained at a temperature within −80° C., preferably within −60° C. of the glass transition temperature of the acrylic resin composition.

More preferably, as at least one of the rolls for such sandwiching, use a roll having an elastic metal sleeve as disclosed in JP-A-2000-153547, JP-A-11-235747, etc., By transferring the roll mirror surface or specific surface shape using low sandwiching pressure, the film surface has excellent smoothness or moderate surface roughness, and the slipperiness of the film surface is excellent, and blocking between films is suppressed. , a film with less internal strain can be obtained.

Further, depending on the purpose, it is also possible to carry out uniaxial stretching or biaxial stretching subsequent to film formation. Uniaxial or biaxial stretching can be carried out using a known stretching device. Biaxial stretching can be carried out in a known manner, such as successive biaxial stretching, simultaneous biaxial stretching, and longitudinal stretching followed by transverse stretching while relaxing the longitudinal direction to reduce bowing of the film. be.

Furthermore, depending on the application, one side or both sides of the acrylic resin film can be given a surface shape such as a hairline, prism, uneven shape, matte surface, rough surface with a certain degree of surface roughness, or knurling at the edge of the film. may be given. Such a surface profile can be imparted by a known method. For example, by sandwiching both sides of a molten film immediately after extrusion or a molded film fed out from a feeding device between two rolls or belts having a surface shape on at least one surface, the surface shape of the roll is changed. A method of transcription can be mentioned.

The thickness of the acrylic resin film is not particularly limited, and is appropriately determined according to the use of the film. When the acrylic resin film is used as the base material of the laminated film, the thickness of the acrylic resin film is determined in consideration of the thickness of the functional layers other than the base material in the laminated film. The thickness of the acrylic resin film is, for example, preferably 20 μm or more and 500 μm or less, more preferably 40 μm or more and 300 μm or less.

According to a preferred embodiment, the acrylic resin film described above has excellent resistance to organic solvents. Therefore, the acrylic resin film can be preferably used as an object (object to be coated) to which the liquid containing the organic solvent is applied.

The liquid containing the organic solvent is not particularly limited, and may be a cleaning liquid or the like. Typically, the liquid containing the organic solvent is preferably a coating liquid for forming the functional layer.

<Laminated film>
The laminated film comprises the acrylic resin film described above and at least one functional layer or other film layer. The laminated film may be provided with a functional layer or a layer made of another film on only one side of the acrylic resin film, or may be provided on both sides. Also, a plurality of functional layers or other films may be stacked and laminated to the acrylic resin film. Moreover, when providing on both sides of the acrylic resin film, each side may be provided with a different functional layer or a layer made of another film.

The functional layer is not particularly limited. As the functional layer, conventionally known various functional layers can be employed without particular limitation. Specific examples of functional layers include a hard coat layer, a low refractive layer, a high refractive layer, an antiglare layer, a light diffusion layer, a matte layer, a chemical resistant layer, an anti-fingerprint layer, an antifouling layer, an antistatic layer, and a polarizing layer. , a colored layer, a design layer, an embossed layer, a light shielding layer, a reflective layer, a conductive layer, a gas barrier layer, a gas absorbing layer, an adhesive layer, a primer layer, and the like. The laminated film may comprise a combination of two or more of these functional layers. Also, one functional layer may have two or more functions.

The other film is not particularly limited, and is a film or sheet having the same function as the functional layer described above, or a surface protection for protecting the outermost surface of an acrylic resin film, a functional layer, or a film layer having other functions. A film, a transfer film having a release layer for transferring a laminated film to a target surface, and the like.
The thickness of each functional layer or other film is not particularly limited, and is appropriately set according to the intended use and function of the laminated film. Typically, the thickness of the laminated film is preferably 20 μm or more and 1 mm or less, more preferably 40 μm or more and 700 μm or less.

<Molded product>
The molded article of the present invention is obtained by laminating the above acrylic resin film and/or laminated film on the surface of the molded article body. Preferable uses of such molded articles include surface protection and decoration of moldings and members having a three-dimensional shape or three-dimensional design, such as vehicle interior materials, building materials, and housings for electrical and electronic equipment.

In addition, the above molded article can also be suitably used for covering at least part of the surface of a member made of a thermoplastic resin, a curable resin, or an inorganic material. Materials for the members include thermoplastic resins such as polycarbonate resins having a bisphenol-based skeleton, fluorene-based skeleton or isosorbide-based skeleton, acrylic resins, styrene resins (AS resins, ABS resins, MAS resins, styrene maleimide resins, styrene maleic anhydride resin, etc.), saturated polyester resin, polyvinyl chloride resin, polyarylate resin, polyphenylene sulfide resin, polyoxymethylene resin, polyamide resin, polylactic acid resin, cellulose acylate resin, polyolefin resin, polyurethane based resins, fluorine resins, and the like. Examples of curable resins include epoxy resins, curable acrylic resins, vinyl ester resins, unsaturated polyester resins, phenol-based resins, melamine-based resins, polyurethane-based resins, and benzoxazine resins. Examples of inorganic materials include hard glass, soft glass, various steel materials, stainless steel materials, copper plates, aluminum-based materials, titanium-based materials, ceramic materials, and stone materials.

The above-mentioned molded article is more preferably used for covering the surface of a member made of transparent resin such as polycarbonate resin, acrylic resin, styrene resin, polyarylate resin, and polyolefin resin. can.

Specific examples of applications for molded products include instrument panels, in-vehicle display front panels, control panels, console boxes, meter covers, door lock pezels, door trims, armrests, steering wheels, power window switch bases, center clusters, dashboards, and shift levers. , Ventilator and other automotive interior applications; weather strips, bumpers, bumper guards, side mudguards, body panels, spoilers, strut mounts, wheel caps, center pillars, door mirrors, center ornaments, emblems, logos, side moldings, door moldings, wind moldings Automotive exterior applications such as windows, head lamp covers, tail lamp covers, windshield parts, camera module covers, front grilles; Buttons, etc., televisions, DVD players, stereo equipment, rice cookers, washing machines, refrigerators, air conditioners, humidifiers, dehumidifiers, fans, and other household electrical and electronic equipment; housings, front panels, buttons, surfaces of furniture products, etc. Applications such as decorative materials, furniture exterior material applications; architectural interior material applications such as wall surfaces, ceilings, floors, bathtubs, toilet seats, etc.; architectural exterior materials such as siding walls, fences, roofs, gates, gable boards, etc. Material use; Surface decorative material use for furniture such as window frames, doors, handrail thresholds, and lintels; Optical member uses such as various displays, lenses, mirrors, goggles, and window glass; Railway vehicles, aircraft, ships, motorcycles, bicycles, etc. Examples include interior and exterior uses of various vehicles other than automobiles.

When using the acrylic resin film and/or laminated film described above, it has a complicated three-dimensional shape, and the surface hardness, scratch resistance, chemical resistance, antifouling property, reflective property, antiglare property, etc. are controlled. , can easily produce molded products with excellent appearance. For this reason, the above-mentioned molded product is preferably used for, among the above-mentioned applications, for example, an in-vehicle display front plate having a planar shape, a curved surface shape, or a three-dimensional shape.

As a method for laminating a molded article comprising the acrylic resin film and/or laminated film described above onto the surface of a molded article, member, or the like, any known method can be used without particular limitation. In particular, as a surface decoration or surface protection method for forming a layer composed of the acrylic resin film and/or laminated film on the surface of a molded article or member having a three-dimensional shape, for example, Japanese Patent Publication No. 63-6339 , JP-B-4-9647, JP-A-7-9480, JP-A-8-323934, JP-A-10-279766, etc., a film in-mold molding method or a film insert molding method, or a patent A three-dimensional laminate molding method similar to the methods described in Japanese Patent No. 3733564 and Japanese Patent No. 3924760 can be preferably used.

In the film in-mold molding method or film insert molding method, a functional layer, a printed decorative layer, a backer sheet, an adhesive layer, a binder layer, etc. are laminated as necessary on the acrylic resin film and/or laminated film described above, A decorative film that has been given a shape in advance by vacuum forming, pressure forming, hot press molding, etc., or not is inserted into the injection mold, and the thermoplastic resin is injected into the mold cavity. This is a method of laminating and integrating a film on the surface of an injection molded article. In the three-dimensional laminate molding method, if necessary, a functional layer, a printed decorative layer, a backer sheet, etc. are laminated on the above-mentioned acrylic resin film and / or laminated film, and an adhesive layer is further laminated. This is a molding method in which a decorative film with an adhesive layer softened in is attached to the surface of a molded body under vacuum or compressed air. At that time, the resin temperature, molding conditions, functional layers, printed layers, decorative layers, vapor deposition layers, adhesive layers, embossed shapes, etc. on the above-mentioned acrylic resin film and / or laminated film, the presence or absence of a backer sheet, etc. can be appropriately set in consideration of the molding method, the type of base resin, the application, and the like.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. In addition, "part" shows a "weight part" below.

(Method for measuring average particle size)
The average particle diameter of the particles of each crosslinked elastic layer is measured in the latex state of each crosslinked elastic layer using a laser diffraction particle size distribution analyzer (Microtrac particle size distribution analyzer MT3000 manufactured by Nikkiso Co., Ltd.). It is the measured volume average particle size.

(Method for measuring graft ratio)
2 g of the multilayer structure polymer particles (C) were weighed, dissolved in 50 ml of methyl ethyl ketone, and centrifuged at 30000 rpm for 1 hour using a centrifuge (CP60E manufactured by Hitachi Koki Co., Ltd.) to separate the insoluble and soluble components. separated. Using the obtained methyl ethyl ketone-insoluble matter, the graft ratio was calculated according to the following formula.
Graft rate (%) = [(weight of insoluble portion of methyl ethyl ketone - R) / R] x 100
However, R is the charged weight of the monofunctional monomer constituting the crosslinked elastic layer (A) in 2 g of the multilayer structure polymer particles (C).

(Production example 1)
<Production of multilayer structure polymer particles (C1)>
An 8 L polymerization apparatus equipped with a stirrer was charged with the following materials.
・Deionized water 200 parts ・Polyoxyethylene lauryl ether sodium phosphate 0.12 parts (manufactured by Toho Chemical Industry Co., Ltd., sodium salt of product RD-510Y)
・Sodium formaldehyde sulfoxylate 0.15 parts ・Ethylenediaminetetraacetate-2-sodium 0.0048 parts ・Ferrous sulfate 0.0012 parts

After the inside of the polymerizer was sufficiently purged with nitrogen gas to create a substantially oxygen-free state, the inside temperature was raised to 60° C., and polyoxyethylene lauryl ether phosphorus was added to the raw material mixture of the crosslinked elastic layer (A1) shown in Table 1. 0.1 part of sodium phosphate was dissolved and added continuously over 180 minutes. After the addition was completed, the polymerization was continued for 0.5 hour to obtain particles of the crosslinked elastic layer (A1). The volume average particle diameter of the particles of the crosslinked elastic layer (A1) was 82 nm. The polymerization conversion rate was 99.0%.

After that, 0.2 part of sodium polyoxyethylene lauryl ether phosphate was charged, and then the raw material mixture for the shell layer (B1) shown in Table 1 was continuously added over 240 minutes. After completion of the addition, polymerization was continued for 1.0 hour to obtain a multi-layer structure polymer particle latex. The polymerization conversion rate was 99.9%. The resulting latex was salted out with magnesium chloride, coagulated, washed with water and dried to obtain a powder of multi-layer structure polymer particles (C1). The graft ratio measured for the multilayer structure polymer particles (C1) was 69%.

(Production example 2)
<Production of multilayer structure polymer particles (C2)>
Polymerization was carried out in the same manner as in Production Example 1 except that the raw material mixture of the crosslinked elastic layer (A2) and the shell layer (B2) shown in Table 1 was used, followed by coagulation, washing with water, and drying to obtain multi-layer structure polymer particles ( A powder of C2) was obtained. The volume average particle diameter of the particles of the crosslinked elastic layer (A2) was 80 nm. The graft rate measured for the multilayer structure polymer particles (C2) was 70%.

(Production example 3)
<Production of multilayer structure polymer particles (C3)>
Same as Production Example 1 except that 0.135 parts of sodium polyoxyethylene lauryl ether phosphate charged at the initial stage of polymerization was used, and the raw material mixture of the crosslinked elastic layer (A3) and shell layer (B3) shown in Table 1 was used. was polymerized, coagulated, washed with water and dried to obtain a powder of multi-layer structure polymer particles (C3). The volume average particle diameter of the particles of the crosslinked elastic layer (A3) was 86 nm. The graft ratio measured for the multilayer structure polymer particles (C3) was 61%.

(Production example 4)
<Production of multilayer structure polymer particles (C4)>
Polymerization was carried out in the same manner as in Production Example 3 except that the raw material mixture of the crosslinked elastic layer (A4) and the shell layer (B4) shown in Table 1 was used, followed by coagulation, washing with water, and drying to obtain multi-layer structure polymer particles ( A powder of C4) was obtained. The volume average particle diameter of the particles of the crosslinked elastic layer (A4) was 85 nm. The graft ratio measured for the multilayer structure polymer particles (C4) was 64%.

(Production example 5)
<Production of multilayer structure polymer particles (C5)>
Same as Production Example 1 except that 0.28 parts of sodium polyoxyethylene lauryl ether phosphate charged at the initial stage of polymerization was used, and the raw material mixture of the crosslinked elastic layer (A5) and shell layer (B5) shown in Table 1 was used. was polymerized, coagulated, washed with water and dried to obtain a powder of multi-layer structure polymer particles (C5). The volume average particle diameter of the particles of the crosslinked elastic layer (A5) was 72 nm. The graft ratio measured for the multilayer structure polymer particles (C5) was 62%.

(Production example 6)
<Production of multilayer structure polymer particles (C6)>
Same as Production Example 1 except that 0.06 parts of sodium polyoxyethylene lauryl ether phosphate charged at the initial stage of polymerization was used, and the raw material mixture of the crosslinked elastic layer (A6) and shell layer (B6) shown in Table 1 was used. was polymerized, coagulated, washed with water and dried to obtain a powder of multi-layer structure polymer particles (C6). The volume average particle diameter of the particles of the crosslinked elastic layer (A6) was 103 nm. The graft ratio measured for the multilayer structure polymer particles (C6) was 66%.

(Production Example 7)
<Production of multilayer structure polymer particles (C7)>
Polymerization was carried out in the same manner as in Production Example 1 except that the raw material mixture of the crosslinked elastic layer (A7) and the shell layer (B7) shown in Table 1 was used, followed by coagulation, washing with water, and drying to obtain multi-layer structure polymer particles ( A powder of C7) was obtained. The volume average particle diameter of the particles of the crosslinked elastic layer (A7) was 77 nm. The graft ratio measured for the multilayer structure polymer particles (C7) was 90%.

(Production Example 8)
<Production of multilayer structure polymer particles (C8)>
Polymerization was carried out in the same manner as in Production Example 3, except that the raw material mixture of the crosslinked elastic layer (A8) and shell layer (B8) shown in Table 1 was used, followed by coagulation, washing with water, and drying to obtain multi-layer structure polymer particles ( A powder of C8) was obtained. The volume average particle diameter of the particles of the crosslinked elastic layer (A8) was 78 nm. The graft rate measured for the multilayer structure polymer particles (C8) was 50%.

(Production Example 9)
<Production of multilayer structure polymer particles (C)>
Polymerization was carried out in the same manner as in Production Example 3 except that the raw material mixture of the crosslinked elastic layer (A9) and the shell layer (B9) shown in Table 1 was used, followed by coagulation, washing with water, and drying to obtain multi-layer structure polymer particles ( A powder of C9) was obtained. The volume average particle diameter of the particles of the crosslinked elastic layer (A9) was 85 nm. The graft ratio measured for the multilayer structure polymer particles (C9) was 66%.

(Production Example 10)
<Production of multilayer structure polymer particles (C10)>
Same as Production Example 1, except that 0.04 part of sodium polyoxyethylene lauryl ether phosphate charged at the initial stage of polymerization was used, and the raw material mixture of the crosslinked elastic layer (A10) and shell layer (B10) shown in Table 1 was used. was polymerized, coagulated, washed with water and dried to obtain a powder of multi-layer structure polymer particles (C10). The volume average particle diameter of the particles of the crosslinked elastic layer (A10) was 112 nm. The graft ratio measured for the multilayer structure polymer particles (C10) was 65%.

(Production Example 11)
<Production of multilayer structure polymer particles (C11)>
Sodium polyoxyethylene lauryl ether phosphate was replaced with 0.28 parts of sodium dioctyl sulfosuccinate as the emulsifier charged at the initial stage of polymerization, and sodium polyoxyethylene lauryl ether phosphate was used as the emulsifier added after polymerization of the crosslinked elastic layer (A). Polymerization was carried out in the same manner as in Production Example 1, except that sodium dioctyl sulfosuccinate was used instead and the raw material mixture of the crosslinked elastic layer (A11) and shell layer (B11) shown in Table 1 was used. The obtained latex was coagulated, washed with water and dried in the same manner except that calcium chloride was used instead of magnesium chloride for the salting out of the latex to obtain a powder of multi-layer structure polymer particles (C11). The volume average particle diameter of the particles of the crosslinked elastic layer (A11) was 80 nm. The graft ratio measured for the multilayer structure polymer particles (C11) was 84%.

(Production Example 12)
<Production of multilayer structure polymer particles (C12)>
Polymerization was carried out in the same manner as in Production Example 11 except that the raw material mixture of the crosslinked elastic layer (A12) and the shell layer (B12) shown in Table 1 was used, followed by coagulation, washing with water, and drying to obtain multi-layer structure polymer particles ( C12) powder was obtained. The volume average particle diameter of the particles of the crosslinked elastic layer (A12) was 80 nm. The graft ratio measured for the multilayer structure polymer particles (C12) was 150%.

(Production Example 13)
<Production of multilayer structure polymer particles (C13)>
Polymerization was carried out in the same manner as in Production Example 11 except that the raw material mixture of the crosslinked elastic layer (A13) and the shell layer (B13) shown in Table 1 was used, followed by coagulation, washing with water, and drying to obtain multi-layer structure polymer particles ( A powder of C13) was obtained. The volume average particle diameter of the particles of the crosslinked elastic layer (A13) was 80 nm. The graft ratio measured for the multilayer structure polymer particles (C13) was 135%.

(Production Example 14)
According to Production Example 5 of Japanese Patent No. 4291994, multilayer structure polymer particles (C14) were produced. The particle diameter of the crosslinked elastic layer was 80 nm, and the graft ratio of the shell layer was 90%.

(Production Example 15)
<Production of multilayer structure polymer particles (G)>
An 8 L polymerization apparatus equipped with a stirrer was charged with the following materials.
・220 parts of deionized water ・0.3 parts of boric acid ・0.03 parts of sodium carbonate ・0.09 parts of sodium N-lauroyl sarcosinate ・0.09 parts of sodium formaldehyde sulfoxylate ・2-sodium ethylenediaminetetraacetate 0.006 parts Ferrous sulfate 0.002 parts

After the inside of the polymerizer was sufficiently replaced with nitrogen gas to make it substantially oxygen-free, the inside temperature was adjusted to 80° C., and 25 parts of vinyl monomer (100% methyl methacrylate), 1 part of allyl methacrylate, 25% of the mixed solution with 0.1 part of t-butyl hydroperoxide was charged at once and polymerized for 45 minutes.

The remaining 75% of this mixture was then added continuously over 1 hour. After the addition was completed, the temperature was maintained for 2 hours to complete the polymerization. An additional 0.2 part of sodium N-lauroyl sarcosinate was also added during this time. Thus, a latex of polymer particles to be the first layer of the core (crosslinked elastic layer (G1)) was obtained. The polymerization conversion rate was 98%.

The obtained latex of polymer particles to be the first layer of the core (crosslinked elastic layer (G1)) was kept at 80° C. in a nitrogen stream, and 0.1 part of potassium persulfate was added. Then, a mixture of 50 parts of a vinyl monomer composition (82% by weight of butyl acrylate and 18% by weight of styrene) and 1 part of allyl methacrylate was continuously added over 5 hours. During this time, 0.1 part of potassium oleate was added in three portions. After the addition of the mixed solution was completed, 0.05 part of potassium persulfate was further added and kept for 2 hours in order to complete the polymerization. Thus, a latex of polymer particles for the core (crosslinked elastic layer (G1)) was obtained. The polymerization conversion rate was 99%. The volume average particle diameter of the particles of the core (crosslinked elastic layer (G1)) was 230 nm.

The latex of the polymer particles of the core (crosslinked elastic layer (G1)) was kept at 80° C., and after adding 0.02 parts of potassium persulfate, the vinyl monomer composition (93.3% by weight of methyl methacrylate) was added. , and 6.7% by weight of butyl acrylate) were continuously added over 1 hour. After completion of addition of the vinyl monomer composition, the mixture was held for 1 hour to obtain a latex of particles in which the inner layer shell was graft polymerized to the crosslinked elastic layer (G1). The polymerization conversion rate was 99%.

A latex of particles obtained by graft polymerization of the inner layer shell to the crosslinked elastic layer (G1) was kept at 80° C., and 10 parts of a vinyl monomer composition (50% by weight of methyl methacrylate and 50% by weight of butyl acrylate) was added to 0.5% by weight. Continuous addition over 5 hours. Hold for 1 hour after completion of addition of the vinyl monomer composition. A latex of particles was obtained. The polymerization conversion rate was 99%.

The obtained latex of the multi-layer structure polymer particles was subjected to salting-out coagulation with calcium chloride, heat treatment and drying to obtain white powdery multi-layer structure polymer particles (G). The average particle size of the multilayer structure polymer particles was 250 nm.

(Example 1)
40 parts of the multilayer structure polymer particles (C1) obtained in Production Example 1 and 60 parts of the thermoplastic resin (D) (methacrylic polymer Sumipex MG5 manufactured by Sumitomo Chemical Co., Ltd., methyl methacrylate content: 95% by weight), Mixed using a Henschel mixer. Next, using a 58 mmΦ single screw extruder (manufactured by Nippon Seiko Co., Ltd.) with a cylinder temperature adjusted to 200 ° C. to 260 ° C., melt kneading is performed at a screw rotation speed of 90 rpm and a discharge rate of 130 kg / hour, and a strand is formed. After cooling in a water tank, it was cut with a pelletizer to obtain pellets of the acrylic resin composition.

The obtained pellets of the acrylic resin composition are melt-kneaded at a discharge rate of 130 kg/hr at a cylinder setting temperature of 180° C. to 240° C. using a 90 mmΦ single-screw extruder with a T-die, and extruded at a die temperature of 240° C. It is discharged from a T-die and brought into contact with both sides of a touch roll equipped with a metal cast roll temperature-controlled to 90°C and an elastic metal sleeve temperature-controlled to 60°C to form a film while cooling and solidifying and winding to obtain a thickness. Acrylic resin films of 75 μm and 125 μm were obtained.

[Examples 2 to 12 and Comparative Examples 1 to 8]
The types and amounts (parts) of the multilayer structure polymer particles (C) and the thermoplastic resin (D), and the amount (parts) of the multilayer structure polymer particles (G) are shown in Tables 2 and 3, respectively. Changed to type and amount (parts). In Table 2, "HM" of the thermoplastic resin (D) is Kuraray Parapet HM (methyl methacrylate content: 100% by weight), and "EX" is Sumitomo Chemical Sumipex EX (methyl methacrylate content: 95% by weight). ). Except for these changes, the acrylic resin films of Examples 2 to 12 and Comparative Examples 1 to 8 with a thickness of 75 μm and 125 μm were obtained in the same manner as in Example 1.

[Comparative Example 9]
According to Example 6 of Japanese Patent No. 4291994, using the multilayer structure polymer particles (C14) obtained in Production Example 14, using Sumipex EX as the thermoplastic resin (D), acrylic particles having a thickness of 75 µm and 125 µm A resin film was obtained.

[Comparative Example 10]
A commercially available acrylic resin film (manufactured by Sumitomo Chemical Co., Ltd., product name Technoloy (registered trademark) S014G, core-shell rubber-containing acrylic resin film) was used.

Using the obtained acrylic resin films of Examples and Comparative Examples, total light transmittance, haze, tensile elongation at break, trimmability, MIT test, surface hardness, and post-stretching haze at room temperature ( Bending whitening resistance) was evaluated. These evaluation results are shown in Tables 2 and 3.

<Total light transmittance, haze value>
Using Haze Meter NDH7000SP manufactured by Nippon Denshoku Kogyo Co., Ltd., the total light transmittance and haze value of a 125 μm thick acrylic resin film and the haze value of a test piece after stretching at room temperature, which will be described later, were measured according to JIS K6174.

<Tensile breaking elongation>
Using a JIS B6732 SDK-600 type dumbbell-shaped test piece punched out of an acrylic resin film having a thickness of 75 μm in the MD direction during extrusion molding, using a Tensilon tensile tester, the distance between gauge lines is 40 mm, and the tensile speed is 200 mm / The tensile elongation at break was measured under conditions of minutes. The value of the tensile elongation at break is the average value excluding the highest value and the lowest value among the measurement results obtained using five test pieces.

<Trimmability>
An acrylic resin film having a thickness of 75 μm was cut into a size of about A4, left at rest at 23° C. for 12 hours or more, and then evaluated under the following conditions.

After fixing the upper end (longer side) of the film to black drawing paper with cellophane tape, the black drawing paper and the film were put together and only the upper end was fixed to a cutter board (OLFA Cutter Mat B160) with cellophane tape. Insert the blade of a cutter (NT Cutter Q-100P manufactured by NT Corporation) into the film at a distance of 10 cm × 10 cm from the right and bottom ends of the film, and set the angle of the cutter blade in the cutting direction (horizontal front direction). The cutter was moved in the cutting direction and cut to the bottom edge of the film. The cutting speed was about 20 cm/s. Using the same film test piece, the cutting position was moved to the left by 2 cm, and the cutting test was performed five times. As for the cutter blade, the cutting edge was cut off for each sample (n=5) and a new cutting edge was used.

Judgment Criteria 5+: (Acceptance) Cutting traces were linear, and no cracks were visually observed in the cutting traces after the test in all samples. Furthermore, the feel during cutting is ductile (continuous and smooth cutting feel).
5: (Acceptance) Cutting traces are linear, and no cracks are visually observed in the cutting traces after the test in all samples. Brittle feel when cutting (at least partially crisp and discontinuous cutting feel)
4: Cutting marks are linear, but 10 or less small cracks (1 mm or less in length) occur per 10 cm of cutting mark length 3: Cutting marks are jagged and large cracks (1 mm or more in length) occur Yes 2: The cutting marks are jagged, and the entire film may crack during cutting 1: The entire film cracks during the first cutting, making it impossible to measure at n = 5

<MIT test>
In accordance with JIS P8115, a test piece obtained by punching an acrylic resin film with a thickness of 125 μm in the MD direction at the time of extrusion molding into a JIS B6732 SDK-600 dumbbell shape is used, and n = 5, and the average value of three points excluding the minimum and maximum values was taken as the MIT value. The measurement conditions were ANGLE: 75, SPEED: 175, MODE: N, a load of 100 g, R: 0.38, and T: 0.25 of the bending device.

<Surface hardness>
Made by Mize Tester No. Using a 601-BI pencil hardness tester, the pencil hardness was measured with a load of 500 g according to JIS K5600-5-4. The measurement of pencil hardness was performed on an acrylic resin film having a thickness of 75 μm.

<Haze value after stretching at room temperature (bending whitening resistance)>
A JIS B6732 SDK-600 dumbbell shape was punched out from an acrylic resin film with a thickness of 125 μm, and a Tensilon tensile tester was used to stretch the film by 15% under the conditions of 23° C., a distance between gauge lines of 40 mm, and a tensile speed of 500 mm/min. rice field. The sample after stretching was allowed to stand at 23° C. for 12 hours, and then the haze value was measured under the conditions described above.

From Table 2, in all of Examples 1 to 12, no cracks were visually observed in the linear cutting marks, and the trimming property (crack resistance during trimming) was excellent, and the pencil hardness was HB. Furthermore, the haze value after stretching at room temperature is less than 20%, indicating that the film also has good resistance to whitening on bending.

On the other hand, from Table 3, in Comparative Examples 1 to 10, the evaluation results of any one or more of trimming properties, surface hardness, and bending whitening resistance are insufficient, and the produced films have excellent trimming properties. , surface hardness, and bending whitening resistance.

Incidentally, Comparative Examples 1 and 3 did not satisfy the requirements for the graft ratio of the shell layer (B) to the crosslinked elastic layer (A), and Comparative Example 2 did not satisfy the crosslinked elastic layer in the acrylic resin composition (E). It does not satisfy the weight ratio requirements of (A). Comparative Example 4 does not satisfy the requirements for the amount of acrylic acid alkyl ester (b-2) in the multilayer structure polymer particles (C). Comparative Examples 5 and 6 do not satisfy the requirements of the relational expression between the volume average particle size of the crosslinked elastic layer (A) and the content of the crosslink/graft crossing agent (H). The requirements for graft ratio of shell layer (B) to layer (A) are also not met. Comparative Examples 7 to 9 did not satisfy the requirements for the amount of the crosslinked elastic layer (A) in the multilayer structure polymer particles (C), and the shell layer (B) was grafted onto the crosslinked elastic layer (A). It does not satisfy the ratio requirement or the amount requirement of the acrylic acid alkyl ester (b-2) in the multilayer structure polymer particles (C).

Claims (10)

Multilayer structure polymer particles (C ),as well as,
An acrylic resin composition (E) for film containing a thermoplastic resin (D) containing 75% by weight or more of methyl methacrylate,
The crosslinked elastic layer (A) comprises 80 % by weight or more of an alkyl acrylate (a-1) having an alkyl group having 1 to 22 carbon atoms , a crosslinking/grafting crossing agent (H) which is allyl (meth)acrylate, and , one or more crosslinked elastomer layers composed of a polymer of a monomer component containing 0% by weight or more and less than 20 % by weight of a monomer (a-2) selected from methacrylic acid esters and aromatic vinyl derivatives ,
The shell layer (B) comprises 50% by weight or more of methyl methacrylate (b-1), alkyl acrylate (b-2) having a linear or branched alkyl group having 1 to 8 carbon atoms, and other Monomer (b-3) 0% by weight or more and less than 50% by weight, and a polymer of monomer components containing a chain transfer agent and not containing a polyfunctional monomer,
The weight ratio of the crosslinked elastic layer (A) to the total amount of the acrylic resin composition (E) is 15.5% by weight or more and less than 21% by weight,
The weight ratio of the acrylic acid alkyl ester (b-2) to the total amount of the acrylic resin composition (E) is 0.8% by weight or more and less than 3% by weight,
The multi-layer structure polymer particles (C) are acrylic resin compositions for films (E), which satisfy the following 1) to 4).
1) The weight ratio of the crosslinked elastic layer (A) to the total amount of the multilayer structure polymer particles (C) is more than 40% by weight and 60% by weight or less.
2) The average particle diameter d (nm) of the crosslinked elastic layer (A) and the content w of the crosslink/graft crossing agent (H) (wherein the content w is the above-mentioned monomer constituting the crosslinked elastomer layer Among the body components, when the total amount of the components excluding the crosslinking/grafting agent (H) is 100 parts by weight, the ratio of the amount of the crosslinking/grafting agent (H) is expressed by the following relational expression: Fulfill.
0.029d≤w≤0.045d
3) The graft ratio of the shell layer (B) to the crosslinked elastic layer (A) is 51% or more and 80% or less.
4) The weight ratio of the acrylic acid alkyl ester (b-2) to the total amount of the multilayer structure polymer particles (C) is 2% by weight or more and less than 5% by weight. The acrylic resin composition (E) for films according to claim 1, wherein a 75 µm-thick film composed of the acrylic resin composition (E) for films satisfies the following 5) to 7).
5) The film is cut with a cutter at 23°C, and no visible cracks are observed at the cut portion formed.
6) Tensile elongation at break at 23°C is 50% or more.
7) The film has a surface hardness of HB or higher in pencil hardness. 3. The acrylic resin composition (E) for films according to claim 1 or 2, wherein a 125 μm thick film composed of the acrylic resin composition (E) for films satisfies the following 8).
8) The number of measurements in the MIT test conforming to JIS P8115 is 50 or more. The acrylic resin composition (E) for films according to any one of claims 1 to 3, wherein a 125 µm-thick film composed of the acrylic resin composition (E) for films satisfies the following 9).
9) When the film is stretched 15% at 23°C, the haze value of the stretched portion is 20% or less. 5. The acrylic resin composition (E) for films according to claim 4, wherein a 125 μm thick film composed of the acrylic resin composition (E) for films satisfies the following 10).
10) When the film is stretched 15% at 23°C, the haze value of the stretched portion is 10% or less. Multilayer structure polymer particles (G) containing a crosslinked elastic layer having an average particle diameter of 150 nm or more and 400 nm or less are added in an amount of 0.5 to 2.5% by weight based on the total amount of the film acrylic resin composition (E). 6. The acrylic resin composition (E) for film according to any one of claims 1 to 5, further containing in proportion. An acrylic resin film (F) composed of the acrylic resin composition (E) for film according to any one of claims 1 to 6. The acrylic resin film (F) according to claim 7, which is used as an object to which a liquid containing an organic solvent is applied. A laminated film comprising the acrylic resin film (F) according to claim 7 or 8 and another film laminated on the film (F). A molded product comprising a molded product main body, and the acrylic resin film (F) according to claim 7 or 8 and/or the laminated film according to claim 9 laminated on the surface of the molded product main body.