JP2020147653A - Acrylic resin composition for film, and acrylic resin film - Google Patents

Abstract

To provide an acrylic resin composition which can form a film having resistance to bending whiteness while achieving both trimming property and surface hardness.SOLUTION: An acrylic resin composition for film (E) contains multilayer structure polymer particles (C) containing a crosslinked elastic body layer (A) having an average particle diameter of 70 nm or more and 110 nm or less and a shell layer (B), and a thermoplastic resin (D) containing 75 wt.% or more of methyl methacrylate. The crosslinked elastic body layer (A) contains 75 wt.% or more of alkyl acrylate (a-1) and a crosslinked elastomer layer containing allyl (meth)acrylate (H). The shell layer (B) contains 50 wt.% or more of methyl methacrylate (b-1), alkyl acrylate (b-2) having an alkyl group having 1 to 12 carbon atoms, and a chain transfer agent. A weight ratio of (A) to (E) is 15.5% or more and less than 21%, and a weight ratio of (b-2) to (E) is 0.8% or more and less than 3%.SELECTED DRAWING: None

Description

The present invention relates to an acrylic resin composition for a film, and an acrylic resin film, a laminated film, and a molded product using the same.

Acrylic resin films made by processing and molding an acrylic resin composition containing a rubber-like elastic body are used for various purposes by taking advantage of excellent properties such as transparency, hardness, weather resistance, and secondary moldability. It has been deployed. For example, it is used for decoration / protection as a paint substitute that is used by laminating a film on the surface of automobile interior / exterior parts, for decoration / protection of the exterior of products such as portable electronic devices, personal computers, and home appliances, and antireflection. , Addition of functions such as anti-glare and anti-fouling properties, and decoration / protection of building materials, furniture, floor materials, etc.

When applied to applications such as decoration and protection of surfaces with such a planar shape or three-dimensional shape, acrylic resin films can be used for pressure molding, vacuum forming, heat press molding, insert / inmold molding, and three-dimensional lamination. Secondary molding such as molding is performed.

Cracks and cracks occur in the film when secondary molding of an acrylic resin film or a decorative / protective film using the acrylic resin film, or when trimming the film after molding or laminating on a decorative base material. It is easy to cause whitening or whitening, but these cause poor appearance of the product and reduce the yield for decoration and protection. For this reason, the acrylic resin film has excellent crack resistance (hereinafter, also referred to as trimming property) that does not cause cracks or cracks during trimming, and less whitening caused by stress during pulling, bending, or cutting (hereinafter, also referred to as trimming property). , Bending and whitening resistance) are required to be compatible. Further, since it is necessary that the surface of the decorated / protected member is not easily damaged during use, the acrylic resin film is also required to have a certain surface hardness.

Furthermore, in recent years, various surface shapes such as various patterns, patterns, gloss, matte, and embossing have been applied to a base material having a three-dimensional shape, such as the surface of an automobile interior member, and weather resistance, antireflection, and antiglare have been applied. When it is required to impart various functions such as property, antifouling property, and chemical resistance to sunscreens, etc., the surface of the acrylic resin film may be given an uneven shape or various functions may be imparted. Additives may be added to the film, or surface treatment or coating layer lamination may be performed on the film. When such surface shape is given, additives are used, surface treatment or coating is performed, the acrylic resin film is cracked due to the uneven portion of the surface, additives, hard and brittle coating, etc. It tends to be easy. Therefore, the acrylic resin film is required to have further improved crack resistance (trimming property) as compared with the conventional one, while maintaining features such as surface hardness and bending whitening resistance.

Various acrylic resin films have been proposed to enable such various decorations and imparting functionality, but surface hardness, trimming property, and bending whitening resistance are in a trade-off relationship with each other. No acrylic resin film has been found that has a sufficient level of.

In order to provide an acrylic resin film applicable to the above-mentioned applications, for example, the reducing viscosity of the thermoplastic polymer constituting the acrylic resin film, the particle size of the rubber-containing polymer, the rubber content, and the like are specified. (Patent Document 1), a method for defining the reduced viscosity of the acrylic polymer, the content of the multilayer structure acrylic polymer (Patent Documents 2 and 3), and rubber particles having different particle diameters are used in combination. A method of suppressing white turbidity of a film during high-temperature processing (Patent Document 4) and the like are known. These films are excellent in transparency and film moldability.

However, the acrylic resin films described in Patent Documents 1 to 4 have not been developed in consideration of the bending whitening resistance of the film. Therefore, with respect to the acrylic resin films described in Patent Documents 1 to 4, when the film is laminated on a molded product having a complicated shape, stress is concentrated on corners and the like, so that the film tends to be whitened. When the film is whitened, the commercial value of the molded product provided with the acrylic resin film is significantly impaired. Further, these acrylic resin films use a large amount of rubber-like elastic body, and if the moldability and crack resistance are sufficiently increased, the surface hardness of the film may decrease.

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 bending whitening resistance. An acrylic resin film obtained by forming the composition (D) into a film has been proposed in Patent Document 5.

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

However, the acrylic resin film described in Patent Document 5 still has a large whitening as a result of using a certain amount of the rubber-containing graft copolymer (B) having a large particle size, and after bending, secondary molding, and decorative molding. It has not been possible to realize a film in which whitening is sufficiently reduced when the film is cut, which may cause a problem in decoration that requires a dark color or high transparency. The amount of rubber-like elastic body used was still small as a whole, and cracks and cracks during trimming were not always sufficiently suppressed.

Patent Documents 6 and 9 disclose an acrylic resin film using a core-shell rubber that defines the relationship between the particle size of the core rubber and the concentration of the crosslinked graft cross-linking agent. However, although whitening is unlikely to occur in this film, the trimming property is low, and even in Example 6 of Patent Document 9, which is considered to have the highest trimming property, the trimming property is not sufficient. In addition, the alkyl acrylate component is larger than the matrix resin component, and the content of the graft polymer of the core-shell rubber, which is considered to be soft, is high. Therefore, the surface hardness is low because the matrix resin phase is softened, and the pencil hardness of Example 6 of Patent Document 9 is actually 2B.

Patent Document 7 discloses an acrylic resin film in which the concentration of the crosslinked graft cross-linking agent of the core-shell rubber is low and the amount of the rubber component is 25-40% by weight of the whole, which is a relatively high concentration. In this document, since the rubber component having a low degree of cross-linking is blended in 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 matrix containing a methacrylic resin matrix having a low acrylate component content and high heat resistance, and an acrylic resin film containing 5-30% by weight of a core-shell rubber having a relatively large particle size. Although this film has a high surface hardness, it has a small amount of rubber components, and since it contains hard crosslinked polymethylmethacrylate particles inside the rubber particles, it has low trimming property and uses a core-shell rubber having a large particle size. There was a problem that bleaching was also relatively large.

Japanese Unexamined Patent Publication No. 8-323934 Japanese Unexamined Patent Publication No. 10-279766 Japanese Unexamined Patent Publication No. 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 situation, the present invention is for a film capable of forming a film having both trimming property (crack resistance at the time of trimming) and surface hardness, and having bending whitening resistance with less whitening at the time of secondary molding or cutting. An object of the present invention is to provide an acrylic resin composition, and an acrylic resin film, a laminated film, and a molded product using the acrylic resin composition.

As a result of intensive studies to solve the above problems, the present inventors have a specific composition in which the particle size of the crosslinked elastic layer and the amount of the crosslinked / graft crosslinker used satisfy a specific relationship and the particle size is in a specific range. In the presence of the crosslinked thermoplastic layer of the above, multilayer structure polymer particles formed by polymerizing a shell layer having a specific composition so as to satisfy a specific graft ratio, the ratio of the crosslinked thermoplastic layer to the entire resin composition and the shell layer. By blending with a thermoplastic resin mainly composed of methyl methacrylate so that the proportions of the alkylate acrylates are within a specific range, both excellent trimming properties and surface hardness, which have not been achieved in the past, are achieved. , It has been found that it is possible to provide an acrylic resin film having excellent bending whitening resistance.

That is, the present invention is as follows.
[1] A multilayer structure polymer containing a crosslinked elastic layer (A) having an average particle diameter of 70 nm or more and 110 nm or less and one or more shell layers (B) graft-polymerized on the crosslinked elastic layer (A). Particle (C) and
Acrylic resin composition (E) for a film containing a thermoplastic resin (D) containing 75% by weight or more of methyl methacrylate.
The crosslinked elastic layer (A) contains 75% by weight or more of alkyl (a-1) acrylate, the crosslinked / graft crosslinker (H) which is allyl (meth) acrylate, and other monomers (a-2) 0. It contains one or more crosslinked elastomer layers composed of polymers of monomer components containing% by weight or more and less than 25% by weight.
The shell layer (B) is an acrylic acid alkyl ester (b-2) having a linear or branched alkyl group having 50% by weight or more of methyl methacrylate (b-1) and 1 to 12 carbon atoms, and the like. Monomer (b-3) is composed of a polymer of a monomer component containing 0% by weight or more and less than 50% by weight and 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 multilayer structure polymer particles (C) are an acrylic resin composition (E) for a film that satisfies 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) exceeds 40% by weight and is 60% by weight or less.
2) The average particle size d (nm) of the crosslinked elastic layer (A) and the content w of the crosslinked / graft crosslinker (H) (however, the content w is the single amount constituting the crosslinked elastomer layer). The ratio of the amount of the cross-linking / graft cross-linking agent (H) when the total amount of the components excluding the cross-linking / graft cross-linking agent (H) among the body components is 100 parts by weight) has 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 (E) for a film according to [1], wherein a film having a thickness of 75 μm composed of the acrylic resin composition (E) for a film satisfies the following 5) to 7).
5) The film was cut with a cutter under the condition of 23 ° C., and there are no visually recognizable cracks in the cut portion formed.
6) The tensile elongation at break at 23 ° C. is 50% or more.
7) The surface hardness of the early film is HB or higher in pencil hardness.
[3] The acrylic resin composition (E) for a film according to [1] or [2], wherein a film having a thickness of 125 μm composed of the acrylic resin composition (E) for a film 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 a film having a thickness of 125 μm composed of the acrylic resin composition for film (E) satisfies the following 9). E).
9) The haze value of the stretched portion when the film is stretched by 15% at 23 ° C. is 20% or less.
[5] The acrylic resin composition (E) for a film according to [4], wherein a film having a thickness of 125 μm composed of the acrylic resin composition (E) for a film satisfies the following 10).
10) The haze value of the stretched portion when the film is stretched by 15% at 23 ° C. is 10% or less.
[6] The multilayer structure polymer particles (G) containing the crosslinked elastic layer having an average particle diameter of 150 nm or more and 400 nm or less are 0.5 to 2.5 with respect to the total amount of the acrylic resin composition (E) for a film. The acrylic resin composition (E) for a film according to any one of [1] to [5], which is further contained in a proportion of% by weight.
[7] An acrylic resin film (F) composed of the acrylic resin composition (E) for a film 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] The molded article main 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 article main body are included. Molding.

According to the present invention, an acrylic resin composition for a film capable of forming a film having bending whitening resistance with less whitening during secondary molding or cutting while achieving both trimming property (crack resistance at the time of trimming) and surface hardness. It is possible to provide an article, and an acrylic resin film, a laminated film, and a molded article using the same. Since the acrylic resin film of the present invention has excellent bending whitening resistance, whitening of the film is suppressed even when laminated on the surface of a molded product having a three-dimensional shape.

Embodiments of the present invention will be 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 made 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, still more preferably 90% by weight or more, from the viewpoint of hardness and moldability. Further, the upper limit value 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 have a structural unit having a specific structure introduced by copolymerization, functional group modification, modification, or the like. Examples of such a specific structure include a glutarimide structure as shown in JP-A-62-89705, JP-A-02-178310, and International Publication No. 2005/54311, and JP-A-2004-168882. Obtained by thermally condensing and cyclizing a lactone ring structure as shown in Japanese Patent Application Laid-Open No. 2006-171464 and the like, and a (meth) acrylic acid unit as shown in Japanese Patent Application Laid-Open No. 2004-307834. Glutamic anhydride structure, maleic anhydride structure as shown in JP-A-5-119217, and N-substituted or unsubstituted maleimide structure as shown in International Publication No. 2009/8451, International Publication No. Examples thereof include aromatic vinyl structures such as alphamethylstyrene to which an aromatic ring is hydrogenated, as shown in 2013/157529 and the like. By introducing these structures into the acrylic resin, the molecular chain can become rigid. As a result, effects such as improvement of heat resistance, improvement of surface hardness, reduction of heat shrinkage, and improvement of chemical resistance can be expected.

Examples of the monomers other than methyl methacrylate, which 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, and the like. Alternatively, vinylidene halide and the like can be mentioned. These other monomers may be one kind or a combination of two or more kinds.

Examples of the acrylic acid derivative include methyl acrylate, n-butyl acrylate, ethyl acrylate, n-propyl acrylate, isobutyl acrylate, t-butyl acrylate, cyclohexyl acrylate, 2-hydroxyethyl acrylate, and acrylate. Acrylic acid esters such as 2--phenoxyethyl, benzyl acrylate, 2- (N, N-dimethylamino) ethyl acrylate, and glycidyl acrylate can be mentioned.

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

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

Examples of the vinyl cyanide derivative include acrylonitrile and methacrylonitrile.

Examples of the halogenated vinylidene 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. Further, any of a known radical polymerization method, living radical polymerization method, anion polymerization method, and cationic polymerization method can be applied.

Further, a thermoplastic resin having 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 the thermoplastic resin that can be used together with the acrylic resin include styrene resin, polyvinyl chloride resin, polycarbonate resin, amorphous saturated polyester resin, polyamide resin, phenoxy resin, polyallylate resin, and olefin- (meth). Examples thereof include acrylic acid derivative resins, cellulose derivatives (cellulose acylate and the like), 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-. Examples thereof include acrylic acid ester resin.

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

<Multilayer polymer particles (C)>
The multilayer structure polymer particles (C) are a multilayer structure polymer including a crosslinked elastic layer (A) and one or more shell layers (B) graft-polymerized on the crosslinked elastic layer (A). It is a particle. According to a preferred embodiment of the present invention, the crosslinked elastic layer (A) is in the form of particles, and 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) exceeds 40% by weight and is 60% by weight or less. Is. Within this range, it is possible to provide a film having excellent trimming property (cracking resistance at the time of trimming), surface hardness, and bending whitening resistance, and in particular, the surface hardness can be improved. It is preferably 41% by weight or more and 58% by weight or less, and 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 amount of the multilayer structure polymer particles (C) blended in the acrylic resin composition (E) for maintaining a constant trimming property increases. There is a possibility that the appearance quality and dimensional accuracy of the film may decrease and the surface hardness may decrease due to the increase in melt viscosity and melt elasticity. If the weight ratio of the crosslinked elastic body (A) exceeds 60% by weight, it becomes difficult to maintain the graft ratio described later within a certain range, and the interface between the multilayer structure polymer particles (C) and the thermoplastic resin (D) There is a possibility that the affinity is insufficient, the trimming property is lowered, and appearance defects such as fish eyes in the acrylic resin film are increased 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 the particles. When the crosslinked elastic layer (A) contains such core particles, the weight of the crosslinked elastic layer (A) shall also include the weight of the core particles.

Further, when the multilayer structure polymer particles (C) are blended into the acrylic resin composition (E), the weight ratio of the crosslinked elastic layer (A) to the total amount of the acrylic resin composition (E) is 15.5 weight. The multilayer structure polymer particles (C) are blended in an amount of% or more and less than 21% by weight. Within this range, it is possible to provide a film having excellent trimming property, surface hardness, and bending whitening resistance. It is preferably 17% by weight or more and 20.9% by weight or less, and 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, the trimming property may be lowered and the bending whitening resistance may be deteriorated. If it exceeds 21% by weight, the surface hardness may decrease.

The crosslinked elastic layer (A) contains 75% by weight or more of alkyl (a-1) acrylate, the crosslinked / graft crosslinker (H) which is allyl (meth) acrylate, and other monomers (a-2) 0. It contains a crosslinked elastomer layer composed of a polymer of a monomer component containing% by weight or more and less than 25% by weight. The crosslinked elastomer layer may be only one layer or may be composed of two or more layers. Further, 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 and polymerized in one step. Further, for the purpose of adjusting the toughness, bleaching resistance, etc. of the film, the film may be appropriately polymerized in two or more stages, and the composition of the monomer component in each stage may be the same. However, they may be different from each other.

As the alkyl acrylate (a-1), an alkyl ester having 1 or more and 22 or less carbon atoms of acrylic acid is particularly preferably used from the viewpoints of excellent polymerizability, low cost, and giving a polymer having a low glass transition temperature. be able to.

Specific examples of preferable monomers include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isobornyl acrylate, acrylate. Cyclohexyl, dodecyl acrylate, stearyl acrylate, heptadecyl acrylate, octadecyl acrylate and the like can be mentioned. 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 alkyl acrylate (a-1) is used in this range, the impact resistance of the acrylic resin film and the elongation at tensile break are good, and excellent trimming property can be achieved. It is preferably 80% by weight or more, and more preferably 85% by weight or more. The upper limit may be 100% or less, and is set according to the amount of the cross-linking / graft cross-linking agent (H) and the other monomer (a-2).

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

The amount of the other monomer (a-2) is set according to the amount of the alkyl acrylate (a-1) and the cross-linking / graft cross-linking agent (H), and is 0 in 100% by weight of the monomer component of the cross-linked elastomer layer. It is more than% by weight and less than 25% by weight. If 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 the time of tensile breakage decreases, and sufficient trimming property may not be achieved. It is preferably 1% by weight or more and less than 30% by weight, and more preferably 5% by weight or more and less than 20% by weight. The other monomer (a-2) is an arbitrary monomer and does not have to be used.

In the crosslinked elastomer layer, allyl acrylate and / or allyl methacrylate (collectively referred to as (meth) allyl acrylate) is used as the cross-linking / graft cross-linking agent (H). As a result, a crosslinked structure is formed, and a graft point for graft-polymerizing the shell layer (B) with respect to the crosslinked elastic layer (A) is formed. 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. More preferably, it is by weight% or more and 4% by weight or less. When the amount of allyl (meth) acrylate used is within the above range, an appropriate degree of cross-linking of the cross-linked elastic body layer (A) and a graft ratio of the shell layer (B) can be realized, so that excellent trimming property and bending resistance can be achieved. Whitening property can be achieved, and it is also preferable from the viewpoint of fluidity of the resin composition at the time of molding.

However, in the crosslinked elastomer layer, a polyfunctional monomer other than allyl (meth) acrylate may be used in combination, and examples of such a polyfunctional monomer include triallyl cyanurate and triallyl isothia. Nurate, diallyl phthalate, diallyl maleate, divinyl adipate, divinylbenzene, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethyl roll propantrimethacrylate, polyethylene glycol dimethacrylate, and dipropylene. Glycoldimethacrylate and the like can be mentioned.

Further, in the crosslinked elastic layer (A), for the purpose of increasing the graft coating efficiency by the shell layer (B) described later, the amount of allyl (meth) acrylate in the crosslinked elastic layer (A) is adjusted to the crosslinked elastic layer (A). It may be changed inside the particle of A) and near the surface. Specifically, as shown in Japanese Patent No. 1460364 and Japanese Patent No. 1786959, the content of allyl (meth) acrylate in the vicinity of the surface of the particles of the crosslinked elastic layer (A) is determined. By increasing the amount more than the inside of the particles, the coating of the crosslinked elastic layer (A) by the shell layer (B) can be improved, the dispersibility in the thermoplastic resin (D) can be improved, or the multilayer structure polymer particles (multilayer structure polymer particles) can be improved. It is possible to suppress a decrease in trimming property due to peeling of the interface between C) and the thermoplastic resin (D). Further, since sufficient coating can be obtained with a relatively small amount of the shell layer (B), the blending amount of the entire multilayer structure polymer particles (C) can be reduced, and the melt processability of the acrylic resin film due to the decrease in melt viscosity can be obtained. , Improvement of film processing accuracy, improvement of surface hardness, etc. can be expected. In this case, the content w of the cross-linking / graft cross-linking agent (H) described later is 100, which is the total amount of the components excluding the cross-linking / graft cross-linking agent (H) among all the monomer components constituting the cross-linked elastomer layer. The ratio of the total amount of the cross-linking / graft cross-linking agent (H) in terms of parts by weight is shown.

The monomer component of the crosslinked elastomer layer includes the control of the molecular weight and crosslink density of the polymer constituting the crosslinked elastomer layer, and the thermal stability associated with the amount of double-bonded terminals of the polymer by stopping the disproportionation of the polymerization reaction. A chain transfer agent may be added for the purpose of controlling the above. The chain transfer agent is usually selected from those used for radical polymerization. Examples of the chain transfer agent include monofunctional or polyfunctional mercaptan compounds having 2 to 20 carbon atoms such as n-octyl mercaptan, n-dodecyl mercaptan, and t-dodecyl mercaptan, mercapto acids, thiophenols, and tetrachloride. Carbon or a mixture thereof and the like are preferable. 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 parts by weight, based on 100 parts by weight of the total amount of the monomer components of the crosslinked elastomer layer. It is 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 formed of the crosslinked elastomer, or may consist of two or more layers formed of the crosslinked elastomer, but the crosslinked elastomer layer may be composed of two or more layers. It may have a concentric spherical multilayer structure including core particles made of a hard or semi-hard elastomer inside. Examples of such core particles include hard crosslinked methacrylic resin particles as shown in Japanese Patent Publication No. 55-27576 and the like, and methyl methacrylate-acrylic acid ester-styrene as shown in Japanese Patent Application Laid-Open No. 4-270751. Examples thereof include semi-rigid crosslinked particles and crosslinked rubber particles having a high degree of crosslinkage. By providing such core particles, improvement in transparency, color tone, etc. may be expected.

Examples of the monomer constituting the hard or semi-hard polymer of the core particles include methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, benzyl methacrylate, and phenoxyethyl methacrylate, methyl acrylate, and acrylic acid. Aromas such as ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, -2-ethylhexyl acrylate, alkyl acrylate such as n-octyl acrylate, styrene, α-methylstyrene and the like. Examples thereof include vinyl cyanide such as vinyl and acrylic nitrile, 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 preferable. Further, as the polyfunctional monomer, allyl (meth) acrylate and the above-mentioned compound for the crosslinked elastomer layer can be used. Further, when polymerizing a hard or semi-hard crosslinked resin layer, in addition to these monomers, a chain transfer agent is used for the purpose of controlling the crosslink density and the thermal stability by reducing the double bond ends of the polymer. It may be used together. As the chain transfer agent, the same chain transfer agent as 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, based on 100 parts by weight of the total amount of the hard or semi-hard crosslinked resin layer. is there.

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 property, 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 determined by using a laser diffraction type particle size distribution measuring device such as the 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 crosslinked / graft crosslinker (H) greatly affect the trimming property, surface hardness, and bending whitening resistance of the film. To achieve the effect of the invention, it is desirable to set both values to satisfy a particular relationship. Specifically, the average particle diameter d (nm) of the crosslinked elastic layer (A) and the content w of the crosslinked / graft crosslinker (H) are the following relational expressions:
0.029d ≤ w ≤ 0.045d
The average particle size of the crosslinked elastic layer (A) and the content of the crosslinked / graft crosslinker (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 property, surface hardness, and bending whitening resistance. If w is less than 0.029d, the bending whitening resistance may deteriorate. Further, if w exceeds 0.045d, the trimming property may decrease. However, the content w of the cross-linking / graft cross-linking agent (H) is 100 parts by weight based on the total amount of the components excluding the cross-linking / graft cross-linking agent (H) among the monomer components constituting the cross-linked elastomer layer. It shows the ratio of the amount of the cross-linking / graft cross-linking agent (H) at the time.

<Shell layer (B)>
In the shell layer (B), a monomer component for the shell layer is graft-polymerized in the presence of particles of the crosslinked elastic layer (A), and the weight of the shell layer (B) is added to the crosslinked elastic layer (A). It can be formed by graft-bonding the coalescing. In the graft polymerization, some polymer components (also referred to as free polymers) that are not graft-bonded to the crosslinked elastic layer (A) may be generated, and this free polymer is also a multilayer structure polymer particles (C). It 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 amount 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 is 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). May cause appearance defects such as fish eyes in the film, and may reduce trimming property and bending whitening resistance. When the weight ratio of the shell layer (B) is 60% by weight or more, the graft cross-linking portion of the graft polymer easily penetrates into the particles of the crosslinked elastic layer (A), and the crosslinked elastic layer becomes hard. Trimmability may decrease. Further, in order to maintain a constant content of the crosslinked elastic body layer (A) in the acrylic resin film (F), the amount of the multilayer structure polymer particles (C) blended in the acrylic resin film (F) increases, and the acrylic The melt viscosity and melt elasticity of the resin composition (E) may increase, making it difficult to form a melt film of an acrylic resin film having excellent dimensional accuracy and appearance quality. Further, when the ratio of the shell layer (B), which is slightly softer than that of the thermoplastic resin (D), is higher in the acrylic resin film, the surface hardness of the film tends to decrease.

The shell layer (B) is an acrylic acid alkyl ester (b-2) having a linear or branched alkyl group having 50% by weight or more of methyl methacrylate (b-1) and 1 to 12 carbon atoms, and the like. The monomer (b-3) is composed of a polymer of 0% by weight or more and less than 50% by weight, and a monomer component containing a chain transfer agent and not containing a polyfunctional monomer. The shell layer (B) may be composed of only one layer, or may be composed 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 enhance the transparency of the film, and has excellent trimming property, surface hardness, and resistance. It is possible to realize a film having foldable whitening property. 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 amount of the acrylic acid alkyl ester (b-2) and other monomers (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 the acrylic acid alkyl ester (b-2) having a linear or branched alkyl group having 1 to 12 carbon atoms include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and isobutyl acrylate. Examples thereof include 2-ethylhexyl acrylate, n-octyl acrylate, and dodecyl acrylate. These may be used alone or in combination of two or more. The alkyl has preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms.

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). ) Is set in a specific range. 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, and more preferably 2.2% by weight or more and 4.0% by weight or less. The latter is 0.8% by weight or more and less than 3% by weight, preferably 0.8% by weight or more and 2.5% by weight or less, and more preferably 0.8% by weight or more and 2.0% by weight or less. More preferably, it is 0.8% by weight or more and 1.5% by weight or less. By setting the amount of the acrylic acid alkyl ester (b-2) used, the amount of the shell layer (B) used, and the amount of the multilayer structure polymer particles (C) used so as to satisfy the above range, respectively. It is possible to realize a film having excellent trimming property, surface hardness, and bending whitening resistance. If the former is less than 2% by weight or the latter is less than 0.8% by weight, the trimming property and bending whitening resistance may be deteriorated. When 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.

Examples of the other monomer (b-3) other than methyl methacrylate (b-1) and acrylic acid alkyl ester (b-2) include a methacrylate ester other than methyl methacrylate and a linear chain having 1 to 12 carbon atoms. Acrylic acid esters other than acrylic acid alkyl esters having a state or branched alkyl group, aromatic vinyl compounds such as styrene and its nuclear substituents, unsaturated nitriles such as acrylonitrile, (meth) acrylic acid and its derivatives, Examples thereof include N-substituted maleimides, maleic anhydride, (meth) acrylamide and the like.

The amount of the other monomer (b-3) is set according to the amount of methyl methacrylate (b-1) and the acrylic acid alkyl ester (b-2), and the monomer component 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 further preferably 0% by weight or more and less than 10% by weight. The other monomer (b-3) is an arbitrary monomer and does not have to be used.

Moreover, you may use a monomer which is a reactive ultraviolet absorber as another monomer (b-3). That is, the shell layer (B) may contain structural units derived from the reactive UV absorber. As a result, an acrylic resin film having good weather resistance and chemical resistance can be obtained.

As the reactive ultraviolet absorber, a known reactive ultraviolet absorber can be used, and is not particularly limited, 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 and the like can be mentioned. More preferably, 2- (2'-hydroxy-5'- is considered from the viewpoint of cost and handleability. Methacryloyloxyethylphenyl) -2H-benzotriazole.

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

The 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 formation of a free polymer not bonded to the crosslinked elastic layer (A). The amount and the like can be controlled. As the chain transfer agent in the shell layer (B), the same chain transfer agent as the above-mentioned chain transfer agent can be used for the crosslinked elastomer layer, but among them, a mercaptan compound is preferable, and t-dodecyl mercaptan, n-dodecyl mercaptan, etc. Especially preferred is 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 thus the shell layer (B) has substantially no crosslinked structure. Is. Here, the polyfunctional monomer has two or more carbon-carbon unsaturated bonds that can be copolymerized with methyl methacrylate (b-1) or acrylic acid alkyl ester (b-2) in one molecule. It refers to a compound, and specific examples thereof include those described above for a crosslinked elastomer 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, a film having excellent trimming property, surface hardness, and bending whitening resistance can be realized. It is preferably 55% or more and 75% or less, and more preferably 60% or more and 70% or less. The graft ratio is the type and amount of the cross-linking agent or graft cross-linking agent used for 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 at the time of polymerization, and the like. It can be adjusted by selecting the type and amount of the chain transfer agent used for 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 be weakened, and the multilayer structure polymer particles in the acrylic resin film (F) ( The dispersibility of C) may be lowered to cause appearance defects such as fish eyes in the film, and trimming property and bending whitening resistance may be lowered. When the graft ratio exceeds 80%, the graft portion of the graft polymer easily penetrates into the crosslinked elastic body layer (A) particles, and the crosslinked elastic body layer becomes hard, which may reduce the trimming property. .. The graft ratio can be measured by a known method such as separating the multilayer structure polymer particles into a crosslinked elastic layer + a graft polymer portion and an ungrafted polymer component with an organic solvent.

<Manufacturing method of 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, mini-emulsion polymerization method, suspension polymerization method, massive polymerization method, solution polymerization method, or dispersion polymerization method can be applied. is there. The emulsification polymerization method is particularly preferable because the adjustment range of the resin structure is large.

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

These initiators may be used as thermally decomposable radical polymerization initiators, or these initiators may be such as sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, hydroxyacetone acid and the like. It may be used as a redox-type polymerization initiator system in which a reducing agent, ferrous sulfate, or ferrous sulfate and a catalyst such as a complex of ethylenediamine tetraacetate-2-sodium are combined.

Among these, 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, etc. It is more preferable to use a redox-type initiator system using the above organic peroxide.

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

The surfactant used for emulsion polymerization of the multilayer structure polymer particles (C)) is not particularly limited. Known surfactants can be widely used for emulsion polymerization. Preferred surfactants include, for example, oleic acid, beef fatty acid, N-lauryl sarcosic acid, alkyl ether carboxylic acid, alkyl sulphonic acid, alkyl ether sulphonic acid, alkylbenzene sulphonic acid, dialkyl sulphosuccinic acid, alkyl sulfate, alkyl. Anionic surfactants such as sodium salts, potassium salts and ammonium salts of acid group-containing compounds such as ether sulfuric acid, fatty acids, alkyl phosphoric acid, alkyl ether phosphoric acid, alkylphenyl ether phosphoric acid and surfactin, and alkylphenols, Examples thereof include nonionic surfactants such as reaction products of aliphatic alcohols and propylene oxide and ethylene oxide. Among these, anionic surfactants having excellent emulsion stabilizing ability are preferable, and sulfonic acid-based, sulfuric acid monoester-based, and phosphoric acid-based surfactants are particularly preferable. These surfactants may be used alone or in combination of two or more.

The multilayer structure polymer particles (C) can be separated and recovered from the latex of the multilayer structure polymer particles (C) obtained by emulsion polymerization by a known method. For example, the multilayer structure polymer particles (C) can be recovered by adding a water-soluble electrolyte to the latex and coagulating it, and then washing and drying the solid content. Further, the multilayer structure polymer particles (C) can be separated by a treatment such as spray drying or freeze drying of the latex, appropriately washed, dried and then recovered.

More preferably, for the purpose of reducing appearance defects and internal foreign substances in the acrylic resin film, the latex of the multilayer structure polymer particles (C) is previously filtered or meshed with a filter or mesh prior to separation and recovery of the multilayer structure polymer particles (C). By filtering, substances that cause foreign matter defects such as environmental foreign matter and polymerization scale are removed.

As the mesh size of the filter and the mesh, for example, those having a diameter larger than the average particle size of the multilayer structure polymer particles (C), which are twice or more larger than the average particle size, can be used. As the filter or mesh, a known filter or mesh used for filtering a liquid medium can be used. The type of filter or mesh, opening, filtration accuracy, filtration capacity, etc. are appropriately selected according to the target application, the type of foreign matter to be removed, the size and amount, and the productivity, but the filter mesh is preferable. The opening or filtration accuracy is 0.5 μm or more and 100 μm or less, and more preferably 1 μm or more and 50 μm or less.

<Multilayer 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 the multilayer structure polymer particles (G) containing a crosslinked elastic layer having a relatively large particle size. There may be. The multilayer structure polymer particles (G) are excellent in the effect of imparting impact resistance and crack resistance to the acrylic resin, and by using this in combination with the multilayer structure polymer particles (C), the acrylic resin film can be trimmed. The balance between properties and surface hardness can be improved.

Like the multilayer structure polymer particles (C), the multilayer structure polymer particles (G) include a crosslinked elastic layer containing one or more crosslinked elastomer layers, and the average particle size 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 located on the surface layer side of the crosslinked elastic layer, like the multilayer structure polymer particles (C). That is, the multilayer structure polymer particles (G) preferably include a crosslinked elastic layer and a shell layer.

The multilayer structure polymer particles (G) have a larger average particle size of the crosslinked elastic layer than that of the multilayer structure polymer particles (C), and have a monomer structure as in the multilayer structure polymer particles (C). Except that there is no limitation on the ratio, the multilayer structure polymer particles (C), the raw materials, the production method, and the like are substantially the same. Particularly preferably, the crosslinked elastic layer of the multilayer structure polymer particles (G) has a concentric spherical multilayer structure in which core particles made of a hard or semi-hard polymer are provided inside the crosslinked elastomer layer. Examples of such core particles include hard crosslinked methacrylic resin particles as shown in Japanese Patent Publication No. 55-27576 and the like, and styrene as shown in Japanese Patent Application Laid-Open No. 4-270751 and International Publication No. 2014/41803. Examples thereof include crosslinked particles having a semi-hard layer made of an acid methyl-acrylic acid ester-styrene copolymer or the like. By introducing such core particles, the transparency, bending whitening resistance, crack resistance, etc. of the multilayer structure polymer particles (G) having a larger particle diameter than the multilayer structure polymer particles (C) can be improved. Can be done.

The blending ratio of the multilayer structure polymer particles (G) can be appropriately set by those skilled in the art, but is 0.5 to 2.5% by weight based on the total amount of the acrylic resin composition (E). Is preferable. When the blending ratio is within this range, good bending whitening resistance can be achieved while enjoying the effect of blending the multilayer structure polymer particles (G). 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 high, but the bending whitening resistance 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. Examples of such additives include antioxidants, ultraviolet absorbers, light stabilizers, light diffusers, matting agents, lubricants, colorants such as pigments and dyes, and antiblocking agents composed of organic crosslinked particles and inorganic particles. Examples thereof include infrared reflectors, plasticizers, and antistatic agents made of metals and metal oxides. Additives are not limited to these. These additives can be used in any amount depending on the type of additive as long as the object of the present invention is 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 property (crack resistance during trimming), surface hardness, and secondary molding. It also has bending whitening resistance with little whitening during time 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 was cut with a cutter under the condition of 23 ° C., and there were no visually recognizable cracks in the formed cut portion. The specific test method is as described in the section of Examples. It corresponds to "5+" or "5" of the judgment criteria described later. This physical property shows excellent trimming property (crack resistance at the time of trimming).

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

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

8) The number of measurements of the MIT test conforming to JIS P8115 for a film having a thickness of 125 μm is 50 or more. 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 as described in the "MIT test" in the examples.

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

Regarding the trimming property of 5), the tensile elongation at break of 6), the surface hardness of 7), and the number of measurements in the MIT test of 8), the crosslinked elastic layer (A) in the entire acrylic resin composition (E). ) Or the ratio of the acrylic acid alkyl ester (b-2), the amount of the acrylic acid alkyl ester (b-2) in the multilayer structure polymer particles (C), and the shell layer (a) with respect to the crosslinked elastic layer (A). The graft ratio of B) has a great influence, and by setting these values within the range specified in the present invention, the requirements of 5), 6), 7), and 8) are satisfied. It becomes possible to do.

9) Regarding the 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 crosslinked / graft crosslinker (H) and the shell layer with respect to the crosslinked elastic layer (A) (9) The graft ratio of B) has a great influence, and by setting each of these values within the range specified in the present invention, the requirement of 9) can be satisfied. In addition to the above, by controlling the ratio of the crosslinked elastic layer (A) to the entire acrylic resin composition (E), it is possible to lower the haze value after stretching at room temperature.

<Manufacturing method of acrylic resin film (F)>
The acrylic resin film (F) can be produced by a known processing method. Specific examples of known processing methods include a melt processing method, a calendar forming method, a press forming method, a solvent casting method, and the like. Examples of the melt processing method include an inflation method and a T-die extrusion method. Further, in the solvent casting method, the acrylic resin composition is dissolved and dispersed in a solvent, and then the obtained dispersion liquid (dope) is poured into a film on a belt-shaped base material. The acrylic resin film is then obtained by volatilizing the solvent from the fluent film-like dope.

Among these methods, a solvent-free melt processing method, particularly a T-die extrusion method, is preferable. According to the melt processing method, there are few restrictions on the thickness of the film to be produced, a film having excellent surface properties can be produced with high productivity, and the load on the natural environment and work environment due to the solvent and the production cost 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, the appearance defect or the inside of the acrylic resin film is used by filtering using a filter or a mesh. It is preferable to remove environmental foreign substances, polymerization scale, deteriorated resin and the like in the acrylic resin composition which cause foreign substances and the like.

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

As such a filter or mesh, a known filter or mesh can be used without particular limitation as long as the filter or mesh has heat resistance and durability according to the melting processing conditions and resistance to a solvent for casting, doping, etc. it can.

When an acrylic resin film is manufactured by melt processing, in order to obtain a high-quality acrylic resin film, the filtration capacity of the molten resin is large, which causes resin deterioration and cross-linked products that impair the quality of the film. A filter with low retention is preferable. For example, it is preferable to use a leaf disc type filter or a pleated type filter in terms of filtration efficiency and productivity.

When the acrylic resin film is manufactured 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 (direction perpendicular to the extrusion direction) of the extruded film is measured online. Based on this, an automatic die device can be used that automatically adjusts the lip clearance of the T-die during extrusion of the film. By applying the automatic die using an appropriate control method, there is a possibility that the thickness accuracy of the acrylic resin film can be improved.

In the production of an acrylic resin film, if necessary, when the film is molded, both sides of the molten film are brought into contact with (sandwich) the cooling roll or the cooling belt at the same time to obtain a film having better surface properties. be able to. In this case, it is preferable that the film in the molten state is simultaneously brought into contact with a roll or a metal belt maintained at a glass transition temperature of −80 ° C. or less, preferably a glass transition temperature of −60 ° C. or less of the acrylic resin composition.

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

Further, depending on the purpose, it is also possible to perform uniaxial stretching or biaxial stretching following the molding of the film. Uniaxial or biaxial stretching can be performed using a known stretching device. Biaxial stretching can be carried out in a known format such as a method of sequentially biaxial stretching, simultaneous biaxial stretching, longitudinal stretching, and then lateral stretching while relaxing the longitudinal direction to reduce the bowing of the film. is there.

Furthermore, depending on the needs of the application, surface shapes such as hairlines, prisms, uneven shapes, matte surfaces, rough surfaces with a certain surface roughness, and knurling to the edges of the film can be applied to one or both sides of the acrylic resin film. It may be given. Such surface shape can be imparted by a known method. For example, the surface shape of a roll is formed by sandwiching both sides of a melted film immediately after extrusion or a molded film unwound from a feeding device between two rolls or belts having a surface shape on at least one surface. Examples include a method of transfer.

The thickness of the acrylic resin film is not particularly limited, and is appropriately determined according to the intended 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 layer 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, and 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 a liquid containing an 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 a functional layer.

<Laminated film>
The laminated film includes the above-mentioned acrylic resin film and a layer composed of at least one kind of functional layer or another film. 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. Further, a plurality of functional layers or other films may be laminated and laminated on the acrylic resin film. When both sides of the acrylic resin film are provided, each surface 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, various conventionally known functional layers can be adopted without particular limitation. Specific examples of the functional layer include a hard coat layer, a low refraction layer, a high refraction layer, an antiglare layer, a light diffusion layer, a matte layer, a chemical resistant layer, a fingerprint resistant layer, an antifouling layer, an antistatic layer, and a polarizing layer. , Colored layer, design layer, embossing layer, light shielding layer, reflective layer, conductive layer, gas barrier layer, gas absorbing layer, adhesive layer, primer layer and the like. The laminated film may include two or more of these functional layers in combination. Further, one functional layer may have a plurality of functions of two or more.

The other film is not particularly limited, and surface protection for protecting the outermost surface of a film or sheet having the same function as the above-mentioned functional layer, an acrylic resin film or a functional layer or a film layer having another function. Examples thereof include a film and a transfer film provided with a release layer for transferring a laminated film to a target surface.
The thickness of each functional layer or other film is not particularly limited, and is appropriately set according to the purpose of use and the function of the laminated film. Typically, the thickness of the laminated film is preferably 20 μm or more and 1 mm or less, and more preferably 40 μm or more and 700 μm or less.

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

Further, the above-mentioned molded product can be suitably used for coating at least a part of the surface of a member made of a thermoplastic resin, a curable resin, or an inorganic material. As the material of the member, as the thermoplastic resin, a polycarbonate resin having a bisphenol skeleton, a fluorene skeleton, an isosorbide skeleton, etc., an acrylic resin, a styrene resin (AS resin, ABS resin, MAS resin, styrene maleimide resin, etc. (Stylene anhydride maleic acid 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 Examples include based resins and fluororesins. Examples of the curable resin include epoxy resin, curable acrylic resin, vinyl ester resin, unsaturated polyester resin, phenolic resin, melamine resin, polyurethane resin, and benzoxazine resin. Examples of the inorganic material include hard glass, soft glass, various steel materials, stainless steel materials, copper plates, aluminum-based materials, titanium-based materials, ceramic materials, stone materials and the like.

The above molded product is more preferably used for coating the surface of a member made of a transparent resin such as a polycarbonate resin, an acrylic resin, a styrene resin, a polyarylate resin, and a polyolefin resin. it can.

Specific examples of molded product applications include instrument panels, in-vehicle display front panels, control panels, console boxes, meter covers, door lock bezels, door trims, armrests, steering wheels, power window switch bases, center clusters, dashboards, and shift levers. , Ventilators 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. For automobile exterior applications such as windows, head lamp covers, tail lamp covers, windshield parts, camera module covers, front grills; housings for portable electronic devices such as smartphones, mobile phones, personal computers, game machines, music players, display windows, etc. Buttons, TVs, DVD players, stereo devices, rice cookers, washing machines, refrigerators, air conditioners, humidifiers, dehumidifiers, fans, and other household electronic and electrical equipment; housings for furniture products, front panels, buttons, surfaces Applications such as decorative materials, and exterior materials for furniture; Interior materials for buildings such as walls, ceilings, floors, bathtubs, toilet seats, etc .; Exterior walls such as siding, walls, roofs, gates, windshields, etc. Materials applications: Surface decorative materials for furniture such as window frames, doors, handrails, and duck doors; Optical components such as various displays, lenses, mirrors, goggles, and window glasses; Railway vehicles, aircraft, ships, motorcycles, bicycles, etc. Examples include interior and exterior applications of various vehicles other than automobiles.

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

A known method can be used without particular limitation as a method for laminating a molded product provided with the above-mentioned acrylic resin film and / or a laminated film on the surface of a molded product, a member, or the like. In particular, as a method of surface decoration or surface protection for forming a layer made of the above-mentioned acrylic resin film and / or laminated film on the surface of a molded body or member having a three-dimensional shape, for example, Japanese Patent Publication No. 63-6339. , A film-in-mold molding method or a film insert molding method similar to the methods described in JP-A-49647, JP-A-7-9480, JP-A-8-323934, JP-A-10-279766, etc. A three-dimensional laminating molding method similar to the method described in Japanese Patent No. 3733564 and Japanese Patent No. 3924760 can be preferably used.

In the film in-mold molding method or the film insert molding method, a functional layer, a printing decorative layer, a backer sheet, an adhesive layer, a binder layer, etc. are laminated on the acrylic resin film and / or the laminated film as needed. A thermoplastic resin is injection-molded into a mold cavity with a decorative film that has been pre-shaped or not given a shape by vacuum molding, pressure molding, hot press molding, etc., inserted into the injection molding die. This is a method of laminating and integrating a film on the surface of an injection molded product. Similarly, in the above-mentioned three-dimensional laminating molding method, a functional layer, a printing decorative layer, a backer sheet, etc. are laminated on the above-mentioned acrylic resin film and / or a laminated film as necessary, and after further laminating an adhesive layer, heat is applied. This is a molding method in which a decorative film with an adhesive layer softened in (1) is attached to the surface of a molded product in a vacuum state or an air pressure state. At that time, the resin temperature, molding conditions, the above-mentioned acrylic resin film, and / or the presence or absence of a three-dimensional design such as a functional layer, a printing layer, a decorative layer, a vapor deposition layer, an adhesive layer, an embossed shape, and a backer sheet on the laminated film, etc. Can be appropriately set in consideration of the molding method, the type of the base resin, the application, and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. In the following, "part" means "part by weight".

(Measuring method of average particle size)
The average particle size of the particles in each cross-linked elastic body layer is determined by using a laser diffraction type particle size distribution measuring device (Microtrac particle size distribution measuring device MT3000, etc., manufactured by Nikkiso Co., Ltd.) in the state of latex of each cross-linked elastic body layer. It is the measured volume average particle diameter.

(Measurement method of graft rate)
2 g of the multilayer structure polymer particles (C) are weighed, dissolved in 50 ml of methyl ethyl ketone, and centrifuged at 30,000 rpm for 1 hour with a centrifuge (CP60E manufactured by Hitachi Koki Co., Ltd.) to separate insoluble and soluble components. separated. Using the obtained insoluble methyl ethyl ketone, the graft ratio was calculated by the following formula.
Graft ratio (%) = [(weight of methyl ethyl ketone insoluble content-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).

(Manufacturing Example 1)
<Manufacturing of multilayer polymer particles (C1)>
The following substances were charged into an 8L polymerization apparatus equipped with a stirrer.
・ 200 parts of deionized water ・ 0.12 parts of sodium polyoxyethylene lauryl ether phosphate (sodium salt of product RD-510Y manufactured by Toho Chemical Industry Co., Ltd.)
・ Sodium formaldehyde sulfoxylate 0.15 parts ・ Ethylenediaminetetraacetic acid-2-sodium 0.0048 parts ・ Ferrous sulfate 0.0012 parts

After sufficiently replacing the inside of the polymerization machine with nitrogen gas to make it substantially oxygen-free, the internal temperature was set 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 completion of the addition, the polymerization was continued for another 0.5 hours 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%.

Then, 0.2 part of sodium polyoxyethylene lauryl ether phosphate was charged, and then the raw material mixture of 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 multilayer structure polymer particle latex. The polymerization conversion rate was 99.9%. The obtained latex was salted out with magnesium chloride, coagulated, washed with water, and dried to obtain a powder of the multilayer structure polymer particles (C1). The graft ratio measured for the multilayer structure polymer particles (C1) was 69%.

(Manufacturing Example 2)
<Manufacturing of multilayer polymer particles (C2)>
The same polymerization as in Production Example 1 was carried out except that the raw material mixture of the crosslinked elastic layer (A2) and the shell layer (B2) shown in Table 1 was used, and the multilayer structure polymer particles were solidified, washed with water and dried. The powder of C2) was obtained. The volume average particle diameter of the particles of the crosslinked elastic layer (A2) was 80 nm. The graft ratio measured for the multilayer structure polymer particles (C2) was 70%.

(Manufacturing Example 3)
<Manufacturing of multilayer polymer particles (C3)>
Same as Production Example 1 except that the amount of sodium polyoxyethylene lauryl ether phosphate charged in the initial stage of polymerization was 0.135 parts and the raw material mixture of the crosslinked elastic layer (A3) and the shell layer (B3) shown in Table 1 was used. Was polymerized, coagulated, washed with water, and dried to obtain a powder of the multilayer 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%.

(Manufacturing Example 4)
<Manufacturing of multilayer polymer particles (C4)>
The same polymerization as in Production Example 3 was carried out except that the raw material mixture of the crosslinked elastic layer (A4) and the shell layer (B4) shown in Table 1 was used, and the multilayer structure polymer particles were solidified, washed with water and dried. The 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%.

(Manufacturing Example 5)
<Manufacturing of multilayer polymer particles (C5)>
Same as Production Example 1 except that 0.28 parts of sodium polyoxyethylene lauryl ether phosphate charged in the initial stage of polymerization was used and the raw material mixture of the crosslinked elastic layer (A5) and the shell layer (B5) shown in Table 1 was used. Was polymerized, coagulated, washed with water, and dried to obtain a powder of the multilayer 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%.

(Manufacturing Example 6)
<Manufacturing of multilayer polymer particles (C6)>
Same as Production Example 1 except that the amount of sodium polyoxyethylene lauryl ether phosphate charged in the initial stage of polymerization was 0.06 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 the multilayer 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%.

(Manufacturing Example 7)
<Manufacturing of multilayer polymer particles (C7)>
The same polymerization as in Production Example 1 was carried out except that the raw material mixture of the crosslinked elastic layer (A7) and the shell layer (B7) shown in Table 1 was used, and the multilayer structure polymer particles were solidified, washed with water and dried. The 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%.

(Manufacturing Example 8)
<Manufacturing of multilayer polymer particles (C8)>
The same polymerization as in Production Example 3 was carried out except that the raw material mixture of the crosslinked elastic layer (A8) and the shell layer (B8) shown in Table 1 was used, and the multilayer structure polymer particles were solidified, washed with water and dried. The powder of C8) was obtained. The volume average particle diameter of the particles of the crosslinked elastic layer (A8) was 78 nm. The graft ratio measured for the multilayer structure polymer particles (C8) was 50%.

(Manufacturing Example 9)
<Manufacturing of multilayer polymer particles (C)>
The same polymerization as in Production Example 3 was carried out except that the raw material mixture of the crosslinked elastic layer (A9) and the shell layer (B9) shown in Table 1 was used, and the multilayer structure polymer particles were solidified, washed with water and dried. The 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%.

(Manufacturing Example 10)
<Manufacturing of multilayer polymer particles (C10)>
Same as Production Example 1 except that the amount of sodium polyoxyethylene lauryl ether phosphate charged in the initial stage of polymerization was 0.04 and the raw material mixture of the crosslinked elastic layer (A10) and the shell layer (B10) shown in Table 1 was used. Was polymerized, coagulated, washed with water, and dried to obtain a powder of the multilayer 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%.

(Manufacturing Example 11)
<Manufacturing of multilayer polymer particles (C11)>
The emulsifier to be charged at the initial stage of polymerization is 0.28 part of sodium dioctyl sulfosuccinate instead of sodium polyoxyethylene lauryl ether phosphate, and the emulsifier to be added after the polymerization of the crosslinked elastic layer (A) is sodium polyoxyethylene lauryl ether phosphate. Instead, sodium dioctyl sulfosuccinate was used, and the same polymerization as in Production Example 1 was carried out except that the raw material mixture of the crosslinked elastic layer (A11) and the 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 the obtained latex was salted out using calcium chloride instead of magnesium chloride to obtain a powder of the multilayer 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%.

(Manufacturing Example 12)
<Manufacturing of multilayer polymer particles (C12)>
The same polymerization as in Production Example 11 was carried out except that the raw material mixture of the crosslinked elastic layer (A12) and the shell layer (B12) shown in Table 1 was used, and the multilayer structure polymer particles were solidified, washed with water and dried. The powder of C12) 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%.

(Manufacturing Example 13)
<Manufacturing of multilayer polymer particles (C13)>
The same polymerization as in Production Example 11 was carried out except that the raw material mixture of the crosslinked elastic layer (A13) and the shell layer (B13) shown in Table 1 was used, and the multilayer structure polymer particles were solidified, washed with water and dried. The 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%.

(Manufacturing Example 14)
Multilayer structure polymer particles (C14) were produced according to Production Example 5 of Japanese Patent No. 429/1994. The particle size of the crosslinked elastic layer was 80 nm, and the graft ratio of the shell layer was 90%.

(Manufacturing Example 15)
<Manufacturing of multilayer polymer particles (G)>
The following substances were charged into an 8 L polymerization apparatus equipped with a stirrer.
・ 220 parts of deionized water ・ 0.3 part of boric acid ・ 0.03 part of sodium carbonate ・ 0.09 part of sodium N-lauroyl sarcosinate ・ 0.09 part of sodium formaldehyde sulfoxylate ・ -2-sodium ethylenediaminetetraacetate 0.006 parts, ferrous sulfate 0.002 parts

After sufficiently replacing the inside of the polymerization machine with nitrogen gas to make it substantially oxygen-free, the internal temperature was set to 80 ° C., and 25 parts of vinyl monomer (100% methyl methacrylate) and 1 part of allyl methacrylate were added. Twenty-five percent of the mixed solution with 0.1 part of t-butylhydroperoxide was charged in a batch and polymerized for 45 minutes.

Subsequently, the remaining 75% of this mixed solution was continuously added over 1 hour. After completion of the addition, the mixture was kept at the same temperature for 2 hours to complete the polymerization. In the meantime, 0.2 parts of sodium N-lauroyl sarcosine was added. In this way, 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 latex of the polymer particles serving as the first layer of the obtained 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 mixed solution consisting 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 period, 0.1 part of potassium oleate was added in 3 portions. After the addition of the mixed solution was completed, 0.05 part of potassium persulfate was further added to complete the polymerization, and the mixture was retained for 2 hours. In this way, a latex of polymer particles of 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., 0.02 part of potassium persulfate was added, and then the vinyl monomer composition (methyl methacrylate 93.3% by weight) was added. , And butyl acrylate (6.7% by weight) were continuously added over 1 hour. After the addition of the vinyl monomer composition was completed, the mixture was held for 1 hour to obtain a latex of particles having an inner shell graft-polymerized on the crosslinked elastic layer (G1). The polymerization conversion rate was 99%.

The latex of the particles having the inner shell graft-polymerized on the crosslinked elastic layer (G1) was kept at 80 ° C., and 10 parts of the vinyl monomer composition (methyl methacrylate 50% by weight and butyl acrylate 50% by weight) was added to 0. It was added continuously for 5 hours. A multilayer structure polymer composed of a core having a two-layer structure (crosslinked elastic layer (G1)) and a shell having two layers (graft polymer layer (G2)), which is held for 1 hour after the addition of the vinyl monomer composition is completed. Particle latex was obtained. The polymerization conversion rate was 99%.

The latex of the obtained multilayer structure polymer particles was salted out, solidified, heat-treated, and dried with calcium chloride to obtain white powdery multilayer 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 a thermoplastic resin (D) (methacrylic polymer Sumitomo Chemical's Sumipex MG5, methyl methacrylate content: 95% by weight) were added. Mixing was performed using a Henschel mixer. Next, using a 58 mmΦ single-screw extruder (manufactured by Japan Steel Works, Ltd.) whose cylinder temperature was adjusted to 200 ° C to 260 ° C, melt-kneading was performed at a screw rotation speed of 90 rpm and a discharge rate of 130 kg / hour to form a strand. After cooling in a water tank, the mixture was cut with a pelletizer to obtain pellets of an acrylic resin composition.

The pellets of the obtained acrylic resin composition are melt-kneaded at a cylinder set temperature of 180 ° C. to 240 ° C. at a discharge rate of 130 kg / hr using a 90 mmΦ single-screw extruder with a T-die, and at a die temperature of 240 ° C. Discharged from a T-die, both sides are brought into contact with a touch roll equipped with a metallic cast roll whose temperature has been adjusted to 90 ° C and an elastic metal sleeve whose temperature has been adjusted to 60 ° C. 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 amounts (parts) of the multilayer structure polymer particles (G) used are shown in Tables 2 and 3, respectively. Changed to type and quantity (part). In Table 2, "HM" of the thermoplastic resin (D) is Kuraray's parapet HM (methyl methacrylate content: 100% by weight), and "EX" is Sumitomo Chemical's Sumipex EX (methyl methacrylate content: 95% by weight). ) Means. Other than these changes, acrylic resin films having a thickness of 75 μm and 125 μm of Examples 2 to 12 and Comparative Examples 1 to 8 were obtained in the same manner as in Example 1.

[Comparative Example 9]
Acrylics with thicknesses of 75 μm and 125 μm using the multilayer structure polymer particles (C14) obtained in Production Example 14 and Sumipex EX as the thermoplastic resin (D) according to Example 6 of Japanese Patent No. 429/1994. A resin film was obtained.

[Comparative Example 10]
A commercially available acrylic resin film (manufactured by Sumitomo Chemical Co., Ltd., product name Technoroy (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, trimming property, MIT test, surface hardness, and haze after stretching at room temperature (haze) according to the following methods. Bending whitening resistance) was evaluated. The evaluation results are shown in Tables 2 and 3.

<Total light transmittance, haze value>
Using a Haze Meter NDH7000SP manufactured by Nippon Denshoku Kogyo, the total light transmittance and haze value of an acrylic resin film having a thickness of 125 μm 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 test piece obtained by punching a 75 μm-thick acrylic resin film into a JIS B6732 SDK-600 dumbbell shape in the MD direction during extrusion molding, using a Tensilon tensile tester, the distance between marked lines is 40 mm and the tensile speed is 200 mm / The tensile elongation at break was measured under the condition of minutes. The value of tensile elongation at break is an average value excluding the highest value and the lowest value among the measurement results obtained using the five test pieces.

<Trimming property>
An acrylic resin film having a thickness of 75 μm was cut into an approximately A4 size, allowed to stand at 23 ° C. for 12 hours or more, and then evaluated under the following conditions.

After fixing the upper end portion (long side side) of the film to the black drawing paper with cellophane tape, the black drawing paper and the film were combined, and only the upper end portion was fixed to the cutter stand (Olfa Cutter Matte B160) with cellophane tape. Insert the cutter (NT Cutter Q-100P manufactured by NT Co., Ltd.) at a distance of 10 cm x 10 cm from the right and lower ends of the film so that the cutting edge penetrates the film, and set the angle of the cutter blade in the cutting direction (horizontal front direction). The temperature was maintained at 45 ° from the horizontal direction toward, and the cutter was moved in the cutting direction to cut to the lower end 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 5 times, and 1 to 5+ was judged according to the following criteria, and 5 or 5+ was regarded as a pass. As for the cutter blade, the cutting edge was cut off every time one sample (n = 5) was carried out, and a new cutting edge was used.

Judgment Criteria 5+: (Pass) The cutting marks are linear, and there are no visual cracks in the cutting marks after the test for all samples. Furthermore, the cutting feel is ductile (continuous and smooth cutting feel).
5: (Pass) The cutting marks are straight, and there are no visual cracks in the cutting marks after the test in all samples. The feel when cutting is brittle (at least partly there is a discontinuous cutting feel with crispness)
4: Cutting marks are linear, but small cracks (length 1 mm or less) occur 10 or less per 10 cm of cutting mark length 3: Cutting marks are jagged and large cracks (length 1 mm or more) occur 2: The cutting marks are jagged and the entire film may crack during cutting 1: The entire film cracks during the first cutting, making measurement at n = 5 impossible.

<MIT test>
Using a test piece of a 125 μm thick acrylic resin film punched into a JIS B6732 SDK-600 dumbbell shape in the MD direction during extrusion molding in accordance with JIS P8115, using a TOYOSEIKI FOLDING ENDURANCE TESTER at 23 ° C. The measurement was performed in step 5, and the average value of the three points excluding the minimum value and the maximum value was used as the MIT value. The measurement conditions were ANGLE: 75, SPEED: 175, MODE: N, load 100 g, bending device R: 0.38, T: 0.25.

<Surface hardness>
Made by Mize Testing Machine No. The pencil hardness was measured using a 601-BI pencil hardness tester under a load of 500 g according to JIS K5600-5-4. The pencil hardness was measured on an acrylic resin film having a thickness of 75 μm.

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

From Table 2, in each 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. It can be seen that the haze value after stretching at room temperature is less than 20%, which is good, and also has good bending whitening resistance.

On the other hand, from Table 3, in Comparative Examples 1 to 10, the evaluation result of any one or more of trimming property, surface hardness, and bending whitening resistance was insufficient, and the produced film had excellent trimming property. , Surface hardness, and bending whitening resistance were not combined.

In addition, Comparative Examples 1 and 3 do not satisfy the requirement of the graft ratio of the shell layer (B) with respect to the crosslinked elastic layer (A), and Comparative Example 2 is the crosslinked elastic layer in the acrylic resin composition (E). It does not meet the weight ratio requirement of (A). Comparative Example 4 does not satisfy the requirement 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 requirement of the relational expression between the volume average particle size of the crosslinked elastic body layer (A) and the content of the crosslinked / graft crosslinker (H), and Comparative Example 6 is a crosslinked elastic body. The requirement for the graft ratio of the shell layer (B) to the layer (A) is also not satisfied. Comparative Examples 7 to 9 do not satisfy the requirement for the amount of the crosslinked elastic layer (A) in the multilayer structure polymer particles (C), and graft the shell layer (B) to the crosslinked elastic layer (A). The rate requirement and the amount requirement of the acrylic acid alkyl ester (b-2) in the multilayer structure polymer particles (C) are also not satisfied.

Claims (10)

Multilayer structure polymer particles (C) including a crosslinked elastic layer (A) having an average particle diameter of 70 nm or more and 110 nm or less and one or more shell layers (B) graft-polymerized on the crosslinked elastic layer (A). ),as well as,
Acrylic resin composition (E) for a film containing a thermoplastic resin (D) containing 75% by weight or more of methyl methacrylate.
The crosslinked elastic layer (A) contains 75% by weight or more of alkyl (a-1) acrylate, the crosslinked / graft crosslinker (H) which is allyl (meth) acrylate, and other monomers (a-2) 0. It contains one or more crosslinked elastomer layers composed of polymers of monomer components containing% by weight or more and less than 25% by weight.
The shell layer (B) is an acrylic acid alkyl ester (b-2) having a linear or branched alkyl group having 50% by weight or more of methyl methacrylate (b-1) and 1 to 12 carbon atoms, and the like. Monomer (b-3) is composed of a polymer of a monomer component containing 0% by weight or more and less than 50% by weight and 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 multilayer structure polymer particles (C) are an acrylic resin composition (E) for a film that satisfies 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) exceeds 40% by weight and is 60% by weight or less.
2) The average particle size d (nm) of the crosslinked elastic layer (A) and the content w of the crosslinked / graft crosslinker (H) (however, the content w is the single amount constituting the crosslinked elastomer layer). The ratio of the amount of the cross-linking / graft cross-linking agent (H) when the total amount of the components excluding the cross-linking / graft cross-linking agent (H) among the body components is 100 parts by weight) has 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 a film according to claim 1, wherein a film having a thickness of 75 μm composed of the acrylic resin composition (E) for a film satisfies the following 5) to 7).
5) The film was cut with a cutter under the condition of 23 ° C., and there are no visually recognizable cracks in the cut portion formed.
6) The tensile elongation at break at 23 ° C. is 50% or more.
7) The surface hardness of the early film is HB or higher in pencil hardness. The acrylic resin composition (E) for a film according to claim 1 or 2, wherein a film having a thickness of 125 μm composed of the acrylic resin composition (E) for a film 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 a film according to any one of claims 1 to 3, wherein a film having a thickness of 125 μm composed of the acrylic resin composition (E) for a film satisfies the following 9).
9) The haze value of the stretched portion when the film is stretched by 15% at 23 ° C. is 20% or less. The acrylic resin composition (E) for a film according to claim 4, wherein a film having a thickness of 125 μm composed of the acrylic resin composition (E) for a film satisfies the following 10).
10) The haze value of the stretched portion when the film is stretched by 15% at 23 ° C. is 10% or less. The multilayer structure polymer particles (G) containing the crosslinked elastic layer having an average particle diameter of 150 nm or more and 400 nm or less are 0.5 to 2.5% by weight based on the total amount of the acrylic resin composition (E) for a film. The acrylic resin composition (E) for a film according to any one of claims 1 to 5, which is further contained in proportion. An acrylic resin film (F) composed of the acrylic resin composition (E) for a 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 including the 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.