Resin composition, molding material, resin molded body and film, and method for producing same

Abstract

Provided are a resin composition and a method for producing same, the resin composition comprising a (meth)acrylic polymer (A) which is a random copolymer and / or a homopolymer, and a (meth)acrylic copolymer (B) which is a block copolymer and / or a graft copolymer, wherein: the (meth)acrylic polymer (A) includes 50% by mass or more of a repeating unit derived from methyl methacrylate; the (meth)acrylic polymer (A) includes a (meth)acrylic polymer (A1) in which the mass average molecular weight in terms of polystyrene, as determined by gel permeation chromatography (GPC), exceeds 130,000; the (meth)acrylic copolymer (B) is a polymer including a polymer (B1) and a polymer (B2) in the same molecule; the polymer (B1) is a polymer including 50% by mass or more of a unit derived from methyl methacrylate and having a glass transition temperature higher than 0°C; and the polymer (B2) is a polymer having a glass transition temperature of 0°C or lower.

Description

Resin composition, molding material, resin molded body, and film, and manufacturing method thereof

[0001] The present invention relates to a resin composition, a molding material containing the resin composition, a resin molded article and a film using the molding material, and methods for producing these.

[0002] Acrylic resins have excellent transparency, weather resistance, high elasticity, surface hardness, and other properties, and are therefore widely used in applications such as display front panels for liquid crystal displays and organic electroluminescence displays, signage, lighting equipment, home appliances, vehicle interior and exterior materials, industrial materials, construction materials, lenses, light guide plates, light collecting members, and optical films used in liquid crystal displays and organic electroluminescence displays.

[0003] In some of these applications, it is required to impart flexibility to acrylic resin products. Also, it is required that acrylic resins can be molded into thin or complex shapes using melt molding methods such as injection molding and extrusion molding. In other words, there is a demand for acrylic resins with excellent melt moldability.

[0004] As a technique for improving the impact resistance of an acrylic resin, for example, Patent Document 1 discloses a resin composition in which a rubber having a core-shell structure (core-shell rubber) having a core part made of crosslinked rubber and a shell part that ensures compatibility and dispersibility with a (meth)acrylic polymer that serves as a matrix is ​​blended with a (meth)acrylic resin.

[0005] The resin composition described in Patent Document 1 contains a core-shell rubber, which increases the melt viscosity and tends to reduce the melt moldability, which has the problem that the use of the resin composition is limited to resin products with large thicknesses or simple shapes.

[0006] To solve the above problems, a resin composition has been proposed in which a block copolymer and / or a graft copolymer is blended with a (meth)acrylic resin instead of a core-shell rubber. In a block copolymer and / or a graft copolymer, two or more polymer segments are chemically bonded to each other. Therefore, the phase-separated structure of a resin composition in which a block copolymer and / or a graft copolymer having a poly(meth)acrylate chain is blended with an acrylic resin is nanometer-sized (called a "microphase-separated structure"). Therefore, in such a resin composition and a molded article obtained by molding the resin composition, it is possible to simultaneously exhibit the properties of both the acrylic resin matrix and the block copolymer and / or the graft copolymer. Furthermore, the properties of each polymer segment of the block copolymer and / or the graft copolymer can also be exhibited.

[0007] A resin composition containing the block copolymer and / or graft copolymer in an acrylic resin forms a microphase-separated structure, and therefore a resin molded article obtained by molding the resin composition can maintain the transparency of the acrylic resin and exhibit excellent properties (e.g., flexibility, impact resistance, etc.) of each polymer segment of the block copolymer and / or graft copolymer.

[0008] As a technique for improving the impact resistance of acrylic resins using block copolymers, for example, Patent Document 2 discloses a method for obtaining a block copolymer by controlled radical polymerization in the presence of nitroxide. Specifically, the patent document discloses a technique for obtaining a sheet-like molded article containing the block copolymer by polymerizing a syrup in a mold to produce a cast sheet. Patent Document 2 describes that the obtained sheet-like molded article contains a (meth)acrylic resin and a block copolymer having a polymethyl methacrylate chain and an n-butyl acrylate-styrene copolymer chain, and has excellent impact resistance and transparency.

[0009] On the other hand, as a method for producing the above-mentioned block copolymers and / or graft copolymers, a method is known in which an acrylic macromonomer (hereinafter referred to as a "macromonomer") is first produced using a very small amount of a cobalt complex with an extremely high chain transfer constant, and then the macromonomer is copolymerized with other monomers to produce the block copolymers and / or graft copolymers. Catalytic chain transfer polymerization (CCTP) is known as a method for producing an acrylic macromonomer using a cobalt complex. A macromonomer is a polymer having a polymerizable functional group in its molecular structure, and is sometimes called a macromer.

[0010] Patent Document 3 discloses a technology in which a macromonomer is produced by CCTP, the obtained macromonomer is used to produce a macromonomer copolymer, and the obtained macromonomer copolymer is then added to an acrylic resin, thereby achieving both impact resistance and transparency.

[0011] Japanese Patent Publication No. 62-21804 Japanese Patent Application Laid-Open No. 2008-274290 Japanese Patent Application Laid-Open No. 2022-065185

[0012] In the method described in Patent Document 2, the synthesis of the block copolymer, the synthesis of the polymethyl methacrylate matrix, and the production of the molded body are carried out simultaneously, and therefore, the method is not suitable for melt molding, and there is a problem that it cannot be molded into thin or complex shapes.

[0013] The method described in Patent Document 3 uses a molding material that is melt-moldable and has excellent moldability to obtain a molded article having good impact resistance and flexibility. However, when a film is produced using this method, the resulting film has a problem of being easily torn and difficult to handle.

[0014] The present invention aims to provide an acrylic resin molding material containing a block copolymer and / or a graft copolymer, which is easy to handle and can give a film having excellent surface smoothness, a molding material using the same, a resin molded product and film obtained by molding the same, and methods for producing these.

[0015] The present inventors have found that the above-mentioned problems can be solved by blending specific (meth)acrylic polymers in combination.

[0016] [1] A resin composition comprising a (meth)acrylic polymer (A) which is a random copolymer and / or a homopolymer, and a (meth)acrylic copolymer (B) which is a block copolymer and / or a graft copolymer, wherein the (meth)acrylic polymer (A) contains 50% by mass or more of repeating units derived from methyl methacrylate, the (meth)acrylic polymer (A) contains a (meth)acrylic polymer (A1) having a polystyrene-equivalent weight average molecular weight determined by gel permeation chromatography (GPC) measurement of more than 130,000, the (meth)acrylic copolymer (B) is a polymer containing a polymer (B1) and a polymer (B2) in the same molecule, the polymer (B1) containing 50% by mass or more of units derived from methyl methacrylate and having a glass transition temperature higher than 0°C, and the polymer (B2) is a polymer having a glass transition temperature of 0°C or lower.

[0017] [2] The resin composition according to [1], wherein the (meth)acrylic polymer (A) further comprises a (meth)acrylic polymer (A2), which has a melt flow rate of 7.0 g / 10 min or more at 230°C and 37.3 N according to JIS K7210 or ISO 1133, and the (meth)acrylic polymer (A2) is contained in an amount of 3 to 15% by mass relative to 100% by mass of the total resin composition.

[0018] [3] The resin composition according to [1] or [2], wherein the (meth)acrylic polymer (A1) has a melt flow rate of less than 7.0 g / 10 min under conditions of 230 ° C. and 37.3 N in accordance with JIS K7210 or ISO 1133.

[0019] [4] The resin composition according to any one of [1] to [3], wherein the (meth)acrylic copolymer (B) is contained in an amount of 15% by mass or more relative to 100% by mass of the total of the resin composition.

[0020] [5] The resin composition according to any one of [1] to [4], wherein the mass average molecular weight of the (meth)acrylic copolymer (B) exceeds 300,000.

[0021] [6] The resin composition according to any one of [1] to [5], wherein the (meth)acrylic copolymer (B) contains a repeating unit derived from a macromonomer (b1) represented by the following general formula (1):

[0022]

[0023] [In formula (1), R ０ ~R ｎ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group. １ ~X ｎ are each independently a hydrogen atom or a methyl group; Z is a terminal group; and n is a natural number from 1 to 10,000.

[0024] [7] A molding material comprising the resin composition according to any one of [1] to [6].

[0025] [8] The molding material according to [7], which is a molding material for a film.

[0026] [9] The molding material according to [7], which is a molding material for extrusion film.

[0027]

[10] A resin molded product obtained by molding the molding material according to any one of [7] to [9].

[0028]

[11] An optical film obtained by molding the molding material according to any one of [7] to [9].

[0029]

[12] A polarizing plate protective film obtained by molding the molding material according to any one of [7] to [9].

[0030]

[13] A polarizing plate comprising the resin molded product according to

[10] .

[0031]

[14] An image display device comprising the resin molded article according to

[10] .

[0032]

[15] A method for producing a resin composition by mixing a (meth)acrylic polymer (A) which is a random copolymer and / or a homopolymer, and a (meth)acrylic copolymer (B) which is a block copolymer and / or a graft copolymer, wherein the (meth)acrylic polymer (A) contains 50% by mass or more of repeating units derived from methyl methacrylate, the (meth)acrylic polymer (A) contains a (meth)acrylic polymer (A1) having a polystyrene-equivalent weight average molecular weight determined by gel permeation chromatography (GPC) measurement of more than 130,000, the (meth)acrylic copolymer (B) is a polymer containing a polymer (B1) and a polymer (B2) in the same molecule, the polymer (B1) contains 50% by mass or more of units derived from methyl methacrylate and has a glass transition temperature higher than 0°C, and the polymer (B2) is a polymer having a glass transition temperature of 0°C or lower.

[0033]

[16] The method for producing a resin composition according to

[15] , wherein the (meth)acrylic polymer (A) further comprises a (meth)acrylic polymer (A2), which has a melt flow rate of 7.0 g / 10 min or more at 230°C and 37.3 N according to JIS K7210 or ISO 1133, and the (meth)acrylic polymer (A2) is contained in an amount of 3 to 15% by mass relative to 100% by mass of the total resin composition.

[0034]

[17] The method for producing a resin composition according to

[15] or

[16] , wherein the (meth)acrylic polymer (A1) has a melt flow rate of less than 7.0 g / 10 min under conditions of 230°C and 37.3 N in accordance with JIS K7210 or ISO 1133.

[0035]

[18] The method for producing a resin composition according to any one of

[15] to

[17] , wherein the (meth)acrylic copolymer (B) is contained in an amount of 15% by mass or more relative to 100% by mass of the total of the resin composition.

[0036]

[19] The method for producing a resin composition according to any one of

[15] to

[18] , wherein the (meth)acrylic copolymer (B) has a mass average molecular weight of more than 300,000.

[0037]

[20] The method for producing a resin composition according to any one of

[15] to

[19] , wherein the (meth)acrylic copolymer (B) contains a repeating unit derived from a macromonomer (b1) represented by the following general formula (1):

[0038]

[0039] [In formula (1), R ０ ~R ｎ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group. １ ~X ｎ are each independently a hydrogen atom or a methyl group; Z is a terminal group; and n is a natural number from 1 to 10,000.

[0040]

[21] A method for producing a resin molded article, comprising producing a resin composition by the method for producing a resin composition according to any one of

[15] to

[20] , and molding a molding material containing the resin composition.

[0041] The resin composition of the present invention and the molding material of the present invention are excellent in moldability and handling properties, and furthermore, can give a film having excellent surface smoothness.

[0042] The handleability of the film of the present invention can be improved by, for example, preventing cracks from propagating in unintended directions when the film is cut; allowing the blade to run smoothly; and suppressing dust generation when the film is cut.

[0043] Hereinafter, embodiments for carrying out the present invention will be described in detail. The present invention is not limited to the following description, and can be carried out in various modifications within the scope of the gist thereof. In the present invention, "(meth)acrylic" means one or both of "acrylic" and "methacrylic". "(meth)acrylate" means one or both of "methacrylate" and "acrylate". The same applies to "(meth)acryloyl".

[0044] In the present invention, "monomer" refers to an unpolymerized compound (monomer component before polymerization), and "repeating unit" and "structural unit" refer to structural units constituting a polymer derived from a monomer formed by polymerization of the monomer. A structural unit constituting a polymer is referred to as a "monomer unit." A "repeating unit" or a "structural unit" may be a unit formed directly by a polymerization reaction, or may be a unit in which a portion of the unit is converted into a different structure by processing the polymer. In the present invention, "mass %" indicates the content of a specific component contained in a total amount of 100 mass %. Unless otherwise specified, in this specification, a numerical range expressed using "to" means a range including the numerical values ​​written before and after "to" as the lower and upper limits, and "A to B" means A or more and B or less.

[0045] In the present invention, the weight average molecular weight (Mw) of the (meth)acrylic polymer (A) means a weight average molecular weight that is a relative molecular weight determined using gel permeation chromatography (GPC) in terms of polystyrene. The weight average molecular weight (Mw) of the (meth)acrylic copolymer (B) means a weight average molecular weight that is a relative molecular weight determined using gel permeation chromatography (GPC) in terms of polymethyl methacrylate (PMMA).

[0046] [Resin Composition] The resin composition of the present invention contains, as essential components, a (meth)acrylic polymer (A) described below and a (meth)acrylic copolymer (B) described below. The (meth)acrylic polymer (A) contains, as an essential component, a (meth)acrylic polymer (A1) described below. Furthermore, the (meth)acrylic polymer (A) preferably contains a (meth)acrylic polymer (A2) described below. The (meth)acrylic copolymer (B) contains, in the same molecule, a polymer (B1) and a polymer (B2) described below, and has at least one of a block copolymer structure and a graft copolymer structure.

[0047] The resin composition of the present invention contains the (meth)acrylic polymer (A1) as an essential component, thereby improving the handleability of the film obtained by molding the resin composition of the present invention and the molding material. The resin composition of the present invention contains the (meth)acrylic copolymer (B) as an essential component, thereby improving the fluidity of the resulting resin composition and molding material, and further improving the flexibility of the resin molded article and film obtained by molding the resin composition and molding material.

[0048] [(Meth)acrylic polymer (A)] The (meth)acrylic polymer (A) is one of the components of the resin composition of the present invention. The (meth)acrylic polymer (A) is a random copolymer and / or a homopolymer, and contains the (meth)acrylic polymer (A1) described below as an essential component.

[0049] The (meth)acrylic polymer (A) contains 50% by mass or more of repeating units derived from methyl methacrylate (hereinafter, may be referred to as "methyl methacrylate units") relative to 100% by mass of the total weight of the (meth)acrylic polymer (A). The (meth)acrylic polymer (A) preferably does not contain a block structure and / or a graft structure.

[0050] The methyl methacrylate units are contained in an amount of preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, relative to 100% by mass of the total weight of the (meth)acrylic polymer (A).

[0051] When the lower limit of the content of methyl methacrylate units in the (meth)acrylic polymer (A) is 50% by mass or more relative to 100% by mass of the total weight of the (meth)acrylic polymer (A), the heat resistance, hardness, scratch resistance, weather resistance, transparency, and processability of the (meth)acrylic polymer (A) can be maintained in a good condition. The upper limit of the content of methyl methacrylate units is not particularly limited, and the (meth)acrylic polymer (A) may be a homopolymer containing 100% by mass of methyl methacrylate units.

[0052] In addition to the repeating units derived from methyl methacrylate, the (meth)acrylic polymer (A) may contain units derived from other comonomers copolymerizable with methyl methacrylate (hereinafter, these units may be referred to as "comonomer units"), from the viewpoint of improving thermal decomposition resistance. In this case, by adjusting the type and content of the comonomer units, it is possible to control the functions of the (meth)acrylic polymer (A), such as the glass transition temperature (Tg), processability, heat resistance, refractive index, weather resistance, mold releasability, and thermal decomposition resistance.

[0053] The upper limit of the content of the comonomer unit in the (meth)acrylic polymer (A) is 50% by mass or less, preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, and particularly preferably 5% by mass or less, relative to 100% by mass of the total mass of the (meth)acrylic polymer (A), because the performance properties of the (meth)acrylic polymer (A), such as heat resistance, hardness, scratch resistance, weather resistance, transparency, and processability, can be favorably maintained.

[0054] The lower limit of the content of the comonomer unit is not particularly limited, and the (meth)acrylic polymer (A) may be a homopolymer containing no comonomer unit, i.e., 100% by mass of methyl methacrylate units.

[0055] Examples of comonomers that form the comonomer units of the (meth)acrylic polymer (A) include the following a) to i): a) (meth)acrylate ester monomers other than methyl methacrylate, such as methyl acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-lauryl (meth)acrylate, n-stearyl (meth)acrylate, cyclohexyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, and phenoxyethyl (meth)acrylate. b) Hydroxyl group-containing (meth)acrylate monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycerol (meth)acrylate, etc. c) Carboxyl group-containing vinyl monomers such as (meth)acrylic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2-(meth)acryloyloxypropyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl phthalic acid, 2-(meth)acryloyloxypropyl phthalic acid, 2-(meth)acryloyloxyethyl maleic acid, 2-(meth)acryloyloxypropyl maleic acid, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxypropyl succinic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, monomethyl itaconate, etc. d) Acid anhydride group-containing vinyl monomers such as maleic anhydride and itaconic anhydride, e) Epoxy group-containing vinyl monomers such as glycidyl (meth)acrylate, glycidyl α-ethyl acrylate and 3,4-epoxybutyl (meth)acrylate, f) Amino group-containing (meth)acrylate vinyl monomers such as dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate.g) Amide group-containing vinyl monomers such as (meth)acrylamide, N-t-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, diacetone acrylamide, maleic acid amide, and maleimide. h) Vinyl monomers such as styrene, α-methylstyrene, vinyl toluene, (meth)acrylonitrile, vinyl chloride, vinyl acetate, and vinyl propionate. i) Polyfunctional vinyl monomers such as divinylbenzene, ethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, allyl (meth)acrylate, and N,N'-methylenebis(meth)acrylamide.

[0056] These may be used alone or in combination of two or more.

[0057] Among these, in terms of easy availability of the monomer, methyl acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred, with methyl acrylate being more preferred.

[0058] The polystyrene-equivalent weight average molecular weight (Mw) of the (meth)acrylic polymer (A) of the present invention, as determined by gel permeation chromatography (GPC), is not particularly limited, but is preferably 50,000 to 300,000, more preferably 70,000 to 200,000, and even more preferably 80,000 to 160,000. If the lower limit of the Mw of the (meth)acrylic polymer (A) is 50,000 or more, the (meth)acrylic polymer (A) is more likely to exhibit its properties, such as heat resistance, hardness, scratch resistance, weather resistance, and transparency. If the upper limit of the Mw of the (meth)acrylic polymer (A) is 300,000 or less, the melt viscosity falls within an appropriate range, resulting in good melt-kneadability and processability.

[0059] The content of the (meth)acrylic polymer (A) is preferably 25% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more, relative to a total of 100% by mass of the resin composition of the present invention. When the content of the (meth)acrylic polymer (A) is 25% by mass or more, the properties characteristic of the (meth)acrylic polymer (A), such as heat resistance, weather resistance, and transparency, can be effectively imparted. When the content of the (meth)acrylic polymer (A) is 90% by mass or less, the content of the (meth)acrylic copolymer (B) increases relatively, making it easier to obtain molding materials with excellent formability and films with excellent handleability.

[0060] [(Meth)acrylic Polymer (A1)] The (meth)acrylic polymer (A1) is used as an essential component of the resin composition of the present invention. The (meth)acrylic polymer (A1) is contained in the (meth)acrylic polymer (A), and is characterized by having a polystyrene-equivalent weight average molecular weight of greater than 130,000 as determined by gel permeation chromatography (GPC). Furthermore, in order to satisfy the aforementioned weight average molecular weight requirement, the (meth)acrylic polymer (A1) preferably has a melt flow rate (MFR) of less than 7.0 g / 10 min, more preferably 4.0 g / 10 min or less, even more preferably 2.0 g / 10 min or less, and particularly preferably 1.0 g / 10 min or less, as measured at 230°C and 37.3 N in accordance with JIS K7210 or ISO 1133. The lower limit of the MFR of the (meth)acrylic polymer (A1) is not particularly limited, but is typically 0.1 g / 10 min or more.

[0061] The inclusion of the (meth)acrylic polymer (A1) can improve the handleability of a molding material using the resin composition of the present invention and a film obtained by molding the molding material. As described above, the handleability of the film can be improved by, for example, preventing cracks from propagating in unintended directions when the film is cut, allowing a blade to run smoothly. Furthermore, dust generation when the film is cut can be suppressed. The monomer units constituting the (meth)acrylic polymer (A1) and the preferred content ratios thereof are the same as those of the (meth)acrylic polymer (A) described above.

[0062] The polystyrene-equivalent weight average molecular weight (Mw) of the (meth)acrylic polymer (A1) measured by gel permeation chromatography (GPC) exceeds 130,000, preferably 135,000 or more, more preferably 140,000 or more, and even more preferably 145,000 or more. If the Mw of the (meth)acrylic polymer (A1) exceeds 130,000, the handleability of the resulting film is improved. Furthermore, the polystyrene-equivalent weight average molecular weight (Mw) of the (meth)acrylic polymer (A1) measured by gel permeation chromatography (GPC) is preferably 300,000 or less, more preferably 200,000 or less, and even more preferably 180,000 or less. If the Mw of the (meth)acrylic polymer (A1) is 300,000 or less, the moldability is improved.

[0063] The content of the (meth)acrylic polymer (A1) is preferably 10% by mass or more, more preferably 30% by mass or more, even more preferably 50% by mass or more, and particularly preferably 60% by mass or more, based on a total of 100% by mass of the resin composition of the present invention. If the content of the (meth)acrylic polymer (A1) is 10% by mass or more, based on a total of 100% by mass of the resin composition of the present invention, the handleability of the resulting film will be good. If the content of the (meth)acrylic polymer (A1) is 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less, based on a total of 100% by mass of the resin composition of the present invention, the moldability will be good.

[0064] Furthermore, the content of the (meth)acrylic copolymer (A1) is preferably 50% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 80% by mass or more, based on 100% by mass of the total (meth)acrylic polymer (A). When the content of the (meth)acrylic polymer (A1) is 50% by mass or more, based on 100% by mass of the total (meth)acrylic polymer (A), the handleability of the resulting film is improved. The content of the (meth)acrylic polymer (A1) may be 100% by mass, based on 100% by mass of the total (meth)acrylic polymer (A). That is, the (meth)acrylic polymer (A) may consist solely of the (meth)acrylic polymer (A1).

[0065] [(Meth)acrylic polymer (A2)] The (meth)acrylic polymer (A2) is a component optionally contained in the resin composition of the present invention. The (meth)acrylic polymer (A2) is contained in the (meth)acrylic polymer (A). The function of the (meth)acrylic polymer (A2) is to adjust the fluidity of the resin composition of the present invention during melt molding. Specifically, it adjusts the relaxation time when the molten resin is extruded from a die during extrusion film molding, and plays a role in improving the smoothness of the film surface that cools and solidifies. That is, by using an appropriate amount of the (meth)acrylic polymer (A2), it is possible to improve the surface smoothness of the film, suppress haze, prevent molding defects, and impart good appearance quality.

[0066] From the viewpoint of improving the surface smoothness of the film and reducing the haze, the (meth)acrylic polymer (A2) preferably has a melt flow rate (MFR) of 7.0 g / 10 min or more, more preferably 10.0 g / 10 min, and even more preferably 12.0 g / 10 min, measured at 230°C and 37.3 N in accordance with JIS K7210 or ISO 1133. There is no particular upper limit to the MFR of the (meth)acrylic polymer (A2), but it is usually 30 g / 10 min or less.

[0067] The polystyrene-equivalent weight average molecular weight (Mw) of the (meth)acrylic polymer (A2) determined by gel permeation chromatography (GPC) measurement is preferably 50,000 to 200,000, more preferably 70,000 to 150,000, and even more preferably 80,000 to 120,000. If the lower limit of Mw of the (meth)acrylic polymer (A2) is 50,000 or more, the (meth)acrylic polymer (A) is more likely to exhibit its properties such as heat resistance, hardness, scratch resistance, weather resistance, and transparency. If the upper limit of Mw of the (meth)acrylic polymer (A2) is 200,000 or less, the melt viscosity and relaxation time fall within appropriate ranges, resulting in good melt-kneadability, processability, and surface smoothness of the resulting film.

[0068] The monomer units constituting the (meth)acrylic polymer (A2) are the same as those in the above-mentioned (meth)acrylic polymer (A). The (meth)acrylic polymer (A2) preferably contains the above-mentioned comonomer units in an amount of 2% by mass or more and 20% by mass or less, more preferably 5% by mass or more and 18% by mass or less, and even more preferably 10% by mass or more and 15% by mass or less. When the (meth)acrylic polymer (A2) contains the comonomer units within the above range, the above-mentioned melt flow rate of the (meth)acrylic polymer (A2) can be easily achieved.

[0069] When the (meth)acrylic polymer (A) contains a (meth)acrylic polymer (A2), the content of the (meth)acrylic polymer (A2) in 100% by mass of the resin composition of the present invention is preferably 1% by mass or more and 20% by mass or less, more preferably 2% by mass or more and 15% by mass or less, even more preferably 3% by mass or more and 15% by mass or less, and particularly preferably 3% by mass or more and 12% by mass or less. By setting the content of the (meth)acrylic polymer (A2) to 1% by mass or more, it is easy to achieve the effects of suppressing haze in the obtained film and suppressing molding defects. By setting the content of the (meth)acrylic polymer (A2) to 20% by mass or less, it is possible to prevent a decrease in mechanical properties such as heat resistance and impact resistance of the resin composition.

[0070] [(Meth)acrylic Copolymer (B)] The resin composition of the present invention contains a (meth)acrylic copolymer (B). The (meth)acrylic copolymer (B) is a block copolymer and / or a graft copolymer containing a polymer (B1) and a polymer (B2) described below in the same molecule, and has at least one of a block copolymer structure and a graft copolymer structure.

[0071] The block and / or graft structure of the (meth)acrylic copolymer (B) may be any of diblock, triblock, multiblock, graft, cyclic, star, comb, dendritic, ladder, etc., or may be a structure combining a plurality of these structures. Among these structures, it is preferable that the (meth)acrylic copolymer (B) contains at least one of the diblock, triblock, and graft structures, since flexibility is expected to be imparted and production is relatively easy.

[0072] In the (meth)acrylic copolymer (B), the polymer (B1) has the function of imparting miscibility and compatibility with the (meth)acrylic polymer (A) and the function of enabling the (meth)acrylic copolymer (B) to be handled as a solid. In the (meth)acrylic copolymer (B), the polymer (B2) has the function of imparting flexibility, impact resistance, and moldability.

[0073] For example, the (meth)acrylic copolymer (B) may be a graft copolymer in which the main chain is constituted by the polymer (B1), and a graft chain made of the polymer (B2) is branched and connected to the main chain made of the polymer (B1). Conversely, the main chain may be the polymer (B2) and the side chain may be (B1). The (meth)acrylic copolymer (B) may be a block copolymer in which a polymer made of the polymer (B1) and a polymer made of the polymer (B2) are connected in series. Furthermore, the graft copolymer may have a structure in which the main chain and / or side chain contains a block copolymer.

[0074] The lower limit of the mass average molecular weight (Mw) of the (meth)acrylic copolymer (B) is preferably more than 120,000, more preferably more than 300,000, even more preferably 500,000 or more, and particularly preferably 700,000 or more. If the Mw of the (meth)acrylic copolymer (B) is more than 120,000, the flexibility and impact resistance of the resin composition, molding material, and molded article will be good. The upper limit of the mass average molecular weight (Mw) of the (meth)acrylic copolymer (B) is preferably 5,000,000 or less, more preferably 3,500,000 or less, and even more preferably 2,000,000 or less. If the Mw of the (meth)acrylic copolymer (B) is 5,000,000 or less, the transparency of the resin composition, molding material, and resulting film will be good. In the present invention, the mass average molecular weight (Mw) of the (meth)acrylic copolymer (B) means a mass average molecular weight, which is a relative molecular weight determined using gel permeation chromatography (GPC) and converted into polymethyl methacrylate (PMMA).

[0075] The content of the (meth)acrylic copolymer (B) relative to a total of 100% by mass of the resin composition of the present invention is preferably 15% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more. If the content of the (meth)acrylic copolymer (B) is 15% by mass or more, it is easy to impart the fluidity as a molding material and the handleability as a film, which are characteristics of the (meth)acrylic copolymer (B). If the content of the (meth)acrylic copolymer (B) relative to a total of 100% by mass of the resin composition of the present invention is 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less. If the content of the (meth)acrylic copolymer (B) is 70% by mass or less, it is easy to obtain the effects of the (meth)acrylic polymer (A), and a film having good heat resistance, surface hardness, transparency, etc. can be obtained.

[0076] [Polymer (B1)] The polymer (B1) is a polymer containing 50% by mass or more of methyl methacrylate units and having a glass transition temperature higher than 0° C. By using the same comonomer units as those in the above-mentioned (meth)acrylic polymer (A) in the polymer (B1), the function of the polymer (B1) to impart miscibility and compatibility with the (meth)acrylic polymer (A) can be effectively exhibited.

[0077] Polymer (B1) preferably contains 70% by mass or more of methyl methacrylate units, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, based on 100% by mass of its total weight. If the lower limit of the content of methyl methacrylate units in polymer (B1) is 70% by mass or more, particularly 80% by mass or more, based on 100% by mass of the total weight of polymer (B1), polymer (B1) has good affinity with (meth)acrylic polymer (A), and miscibility and compatibility are improved. There is no particular upper limit on the content of methyl methacrylate units in polymer (B1), and polymer (B1) may be a homopolymer of 100% by mass of methyl methacrylate.

[0078] In addition to methyl methacrylate units, the polymer (B1) may contain other comonomer units copolymerizable with methyl methacrylate depending on the purpose of the (meth)acrylic copolymer (B). For example, when the polymer (B1) contains acrylate units as comonomer units, depolymerization of the polymer (B1) when exposed to high-temperature conditions such as melt molding can be suppressed, thereby improving thermal decomposition resistance. Furthermore, by adjusting the type and content of the comonomer units, the glass transition temperature (Tg), processability, heat resistance, refractive index, weather resistance, mold releasability, thermal decomposition resistance, and other properties of the polymer (B1) can be controlled.

[0079] The upper limit of the content of the comonomer unit in the polymer (B1) is preferably 20% by mass or less relative to 100% by mass of the total mass of the polymer (B1), since this allows good maintenance of performance such as heat resistance, hardness, scratch resistance, weather resistance, transparency, processability, etc. The lower limit of the content of the comonomer unit in the polymer (B1) is not particularly limited, and the polymer (B1) may not contain a comonomer unit, i.e., may be a homopolymer of methyl methacrylate.

[0080] Examples of the comonomers that form the comonomer units of the polymer (B1) include the comonomers a) to i) described above as the comonomers that form the comonomer units of the (meth)acrylic polymer (A). These may be used alone or in combination of two or more.

[0081] As the comonomer of the comonomer unit contained in the polymer (B1), methyl acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred, and methyl acrylate is more preferred, in terms of easy availability of the monomer.

[0082] The polymer (B1) preferably contains a structural unit derived from the macromonomer (b1) described below. In this case, the macromonomer (b1) may contain a methyl methacrylate unit.

[0083] The glass transition temperature (Tg) of the polymer (B1) is higher than 0°C, preferably 50°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher. When the glass transition temperature (Tg) of the polymer (B1) is higher than 0°C, it is expected to have effects such as improving the handleability of the (meth)acrylic copolymer (B) and improving the heat resistance of the resin composition, molded article, and film of the present invention. There is no particular upper limit to the glass transition temperature (Tg) of the polymer (B1), but from the viewpoint of ease of availability, it is usually 130°C or lower. In the present invention, the Tg of the polymer (B1) can be calculated using Fox's formula, employing the values ​​described in known literature such as the Polymer Handbook (POLYMER HANDBOOK FOURTH EDITION 2003) as the Tg of a homopolymer of a monomer that is a constituent unit of the polymer (B1). Alternatively, the dynamic viscoelasticity of the obtained resin molded article can be measured, and the value of tan δ can be used as the Tg.

[0084] The lower limit of the mass average molecular weight (Mw) of the polymer (B1) is preferably 3,000 or more, more preferably 10,000 or more, even more preferably 15,000 or more, and particularly preferably 20,000 or more. When the Mw of the polymer (B1) is 3,000 or more, the affinity of the polymer (B1) with the (meth)acrylic polymer (A) is improved, and miscibility and compatibility can be expected. The upper limit of the mass average molecular weight (Mw) of the polymer (B1) is preferably 1,000,000 or less, more preferably 80,000 or less, even more preferably 60,000 or less, and particularly preferably 40,000 or less. When the Mw of the polymer (B1) is 1,000,000 or less, the melt viscosity falls within an appropriate range. In the present invention, the weight average molecular weight (Mw) of the polymer (B1) means a weight average molecular weight which is a relative molecular weight determined using gel permeation chromatography (GPC) and converted into polymethyl methacrylate (PMMA).

[0085] The polymer (B1) may be a mixture of two or more polymers. In this case, the mass average molecular weight (Mw) is calculated as the value of the entire polymer (B1). When multiple types of polymers (B1) with different mass average molecular weights (Mw) are used in combination, the polymer (B1) with a lower molecular weight plays a role in reducing the syrup viscosity and preventing crosslinking of the copolymer, while the polymer (B1) with a higher molecular weight plays a role in ensuring compatibility with the matrix resin when used as an additive.

[0086] The content of polymer (B1) in (meth)acrylic copolymer (B) is preferably 35% by mass or more and 75% by mass or less, based on 100% by mass of the total weight of (meth)acrylic copolymer (B). If the lower limit of the content of polymer (B1) is 35% by mass or more, it becomes easier to obtain a (meth)acrylic copolymer (B) having excellent miscibility and compatibility with the (meth)acrylic polymer (A). The lower limit of the content of polymer (B1) is preferably 40% by mass or more, more preferably 45% by mass or more, and even more preferably 50% by mass or more. If the upper limit of the content of polymer (B1) is 75% by mass or less, it becomes easier to obtain the effect of imparting flexibility by polymer (B2). The upper limit of the content of polymer (B1) is preferably 70% by mass or less, more preferably 65% ​​by mass or less.

[0087] [Polymer (B2)] The polymer (B2) imparts functions such as film flexibility, impact resistance, and improved flowability during melt molding to the (meth)acrylic copolymer (B) and the resin composition, molding material, and resin molded article of the present invention using the same.

[0088] The glass transition temperature (Tg) of polymer (B2) is 0°C or lower, preferably -10°C or lower, more preferably -20°C or lower, and even more preferably -35°C or lower. When the glass transition temperature (Tg) of polymer (B2) is 0°C or lower, effects such as improved flexibility, impact resistance, and flowability during melt molding can be expected. There is no particular lower limit for the glass transition temperature (Tg) of polymer (B2), but from the viewpoint of ease of availability, it is usually -70°C or higher. In the present invention, the Tg of polymer (B2) can be calculated by using the Fox equation, employing the values ​​described in known literature such as the Polymer Handbook (POLYMER HANDBOOK FOURTH EDITION 2003) as the Tg of a homopolymer of a monomer that is a constituent unit of polymer (B2). Alternatively, dynamic viscoelasticity measurement can be performed on the obtained resin molded product, and the value of tan δ can be used as the Tg.

[0089] The content of polymer (B2) in (meth)acrylic copolymer (B) is preferably 25% by mass or more and 65% by mass or less, based on 100% by mass of the total weight of the (meth)acrylic copolymer (B). If the lower limit of the content of polymer (B2) is 25% by mass or more, the (meth)acrylic copolymer (B) is more likely to provide the effects of improving flexibility, impact resistance, and moldability. The lower limit of the content of polymer (B2) is preferably 25% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more. If the upper limit of the content of polymer (B2) is 65% by mass or less, the (meth)acrylic copolymer (B) becomes easy to handle. The upper limit of the content of polymer (B2) is preferably 65% ​​by mass or less, more preferably 60% by mass or less, even more preferably 55% by mass or less, particularly preferably 50% by mass or less, and most preferably 45% by mass or less.

[0090] The refractive index of the polymer (B2) is preferably set so that the difference in refractive index between the polymer (B1) and the (meth)acrylic polymer (A) is small. This results in good transparency of the resin composition, molding material, and molded article of the present invention. The refractive index difference between the polymer (B2) and the polymer (B1) is preferably 0.1 or less, more preferably 0.05 or less, and even more preferably 0.02 or less. Similarly, the refractive index difference between the polymer (B2) and the (meth)acrylic polymer (A) is preferably 0.1 or less, more preferably 0.05 or less, and even more preferably 0.02 or less.

[0091] The mass average molecular weight (Mw) of the polymer (B2) is preferably 3,000 or more, more preferably 10,000 or more, even more preferably 15,000 or more, and particularly preferably 20,000 or more. When the Mw of the polymer (B2) is 3,000 or more, the impact resistance is good. Furthermore, the mass average molecular weight (Mw) of the polymer (B2) is preferably 2,500,000 or less, more preferably 2,000,000 or less, even more preferably 1,500,000 or less, and particularly preferably 1,000,000 or less. When the Mw of the polymer (B2) is 2,500,000 or less, the transparency of the resin composition, molding material, and film of the present invention is good.

[0092] The mass average molecular weight (Mw) of the polymer (B2) can be calculated from the mass average molecular weight (Mw) of the entire (meth)acrylic copolymer (B) and the weight ratio of the polymer (B1) to the polymer (B2). １ It can be determined by a method such as H-NMR. For example, when the mass average molecular weight (Mw) of the (meth)acrylic copolymer (B) is 100,000 and the proportion of the polymer (B2) in a total of 100 mass% of the (meth)acrylic copolymer (B) is 40 mass%, the mass average molecular weight (Mw) of the polymer (B2) can be calculated as 100,000 × 0.4 = 400,000.

[0093] [Monomer (b2)] Monomer (b2) is a monomer used as a raw material for polymer (B2). Monomer (b2) is not particularly limited as long as it can produce a (meth)acrylic copolymer (B), and various polymerizable monomers can be used as needed. Specifically, it is preferable to mainly use acrylates or aromatic vinyls in order to set a low glass transition temperature (Tg) to impart flexibility, impact resistance, and moldability, and to adjust the refractive index. Furthermore, other monomers can be used as needed.

[0094] The acrylate used in monomer (b2) is preferably 70% by mass or more, more preferably 79% by mass or more, and even more preferably 81% by mass or more, relative to 100% by mass of the total weight of monomer (b2). If the lower limit of the acrylate content is 70% by mass or more, the (meth)acrylic copolymer (B) is provided with the effect of improving flexibility, impact resistance, and moldability. If the acrylate content of monomer (b2) is low, the effect of improving flexibility, impact resistance, and moldability may be insufficient. The upper limit of the acrylate content in monomer (b2) is not particularly limited, but is preferably less than 100% by mass, more preferably 95% by mass or less, and even more preferably 90% by mass or less, relative to 100% by mass of the total mass of monomer (b2).

[0095] The glass transition temperature (Tg) of the acrylate homopolymer is preferably 0° C. or lower, since this can improve the impact resistance of the resulting resin molded article. In the present invention, the Tg of the acrylate homopolymer can be calculated using the Fox formula using values ​​described in known documents such as the Polymer Handbook (POLYMER HANDBOOK FOURTH EDITION 2003).

[0096] Examples of the acrylate used in the monomer (b2) include acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, n-lauryl acrylate, n-stearyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, and phenoxyethyl acrylate; hydroxyl group-containing acrylates such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, and glycerol acrylate; 2-acryloyloxyethyl hexahydrophthalic acid, 2-acryloyloxypropyl hexahydrophthalic acid, 2-acryloyloxyethyl phthalic acid, 2-acryloyloxyethyl phthalic acid, and 2-acryloyloxyethyl acrylate; Carboxy group-containing acrylates such as 2-acryloyloxypropyl phthalate, 2-acryloyloxyethyl maleate, 2-acryloyloxypropyl maleate, 2-acryloyloxyethyl succinate, and 2-acryloyloxypropyl succinate; epoxy group-containing acrylates such as glycidyl acrylate, glycidyl α-ethyl acrylate, and 3,4-epoxybutyl acrylate; amino group-containing acrylates such as dimethylaminoethyl acrylate and diethylaminoethyl acrylate; and polyfunctional acrylates such as ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,6-hexanediol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, allyl acrylate, and N,N'-methylenebisacrylamide. These can be used alone or in combination of two or more.

[0097] Among the above-mentioned monomers, 2-ethylhexyl acrylate, 4-hydroxybutyl acrylate, n-butyl acrylate, n-propyl acrylate, ethyl acrylate, and 2-hydroxyethyl acrylate are preferred because the Tg of the homopolymer of the monomer is 0° C. or less. Furthermore, methyl acrylate, ethyl acrylate, and n-butyl acrylate are preferred because they are easily available.

[0098] The aromatic vinyl that can be used in the monomer (b2) is used for the purpose of adjusting the refractive index of the polymer (B2) and adjusting the polymerization rate when producing the polymer (B2) and the (meth)acrylic copolymer (B). The content of the aromatic vinyl used in the monomer (b2) is preferably 10 to 30% by mass, more preferably 13 to 21% by mass, and even more preferably 15 to 19% by mass, relative to 100% by mass of the total mass of the monomer (b2). When the content of the aromatic vinyl contained in the monomer (b2) is 10% by mass or more, the resin composition, molding material, and molded article of the present invention can exhibit good transparency. When the content of the aromatic vinyl contained in the monomer (b2) is 30% by mass or less, the polymerization reaction rate when producing the (meth)acrylic copolymer (B) can be sufficiently fast.

[0099] Examples of aromatic vinyls include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene, p-t-butylstyrene, vinylethylbenzene, vinyltoluene, vinylxylene, vinylnaphthalene, diphenylethylene, and divinylbenzene. Among these, styrene is preferred from the viewpoints of practical physical properties and productivity. These can be used alone or in combination of two or more.

[0100] Monomer (b2) may contain other monomers copolymerizable with the acrylate and the aromatic vinyl, as needed. Examples of such other monomers include methacrylates such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, n-lauryl methacrylate, n-stearyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, and phenoxyethyl methacrylate; hydroxyl group-containing methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, and glycerol methacrylate; 2-methacryloyloxyethyl hexahydrophthalic acid, 2-methacryloyloxypropyl hexahydrophthalic acid, and 2-methacryloyloxypropyl hexahydrophthalic acid; Carboxy group-containing methacrylates such as 2-methacryloyloxyethyl phthalate, 2-methacryloyloxypropyl phthalate, 2-methacryloyloxyethyl maleate, 2-methacryloyloxypropyl maleate, 2-methacryloyloxyethyl succinate, and 2-methacryloyloxypropyl succinate; epoxy group-containing methacrylates such as glycidyl methacrylate and 3,4-epoxybutyl methacrylate; amino group-containing methacrylates such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; polyfunctional methacrylates such as ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, tripropylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and allyl methacrylate; and the like. One or more of these may be appropriately selected and used.

[0101] Further, examples of other monomers include carboxyl group-containing vinyl monomers such as (meth)acrylic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, and monomethyl itaconate; acid anhydride group-containing vinyl monomers such as maleic anhydride and itaconic anhydride; amide group-containing vinyl monomers such as (meth)acrylamide, N-t-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, diacetone acrylamide, maleic acid amide, and maleimide; and vinyl monomers such as (meth)acrylonitrile, vinyl chloride, vinyl acetate, and vinyl propionate. When other monomers are used, the amount thereof is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, relative to 100% by mass of the total of monomer (b2). Other monomers may not be used.

[0102] [Method for producing (meth)acrylic copolymer (B)] Examples of methods for producing the (meth)acrylic copolymer (B) according to the present invention include living polymerization methods and methods using a macromonomer (b1) described below. Examples of living polymerization methods include living radical polymerization methods and living anionic polymerization methods. Examples of living radical polymerization methods include reversible addition-fragmentation chain transfer polymerization (RAFT), atom transfer radical polymerization (ATRP), nitroxide-mediated polymerization (NMP), and living radical polymerization with organotellurium as a growing terminal (TERP). The method using macromonomer (b1) is advantageous in that the (meth)acrylic copolymer (B) can be produced relatively easily. The method using macromonomer (b1) is preferred because it has the advantage of not requiring the removal of catalyst or auxiliary residues or terminal treatment steps required in living polymerization methods.

[0103] [Method for Producing (Meth)acrylic Copolymer (B) Using Macromonomer] In a method for producing a (meth)acrylic copolymer (B) using a macromonomer, the macromonomer may be used as a raw material for either polymer (B1) or polymer (B2). A macromonomer copolymer is obtained by copolymerizing the macromonomer with a comonomer copolymerizable with the macromonomer. This macromonomer copolymer is used as the (meth)acrylic copolymer (B). Here, as an example, a method for producing a macromonomer copolymer by using macromonomer (b1) as a raw material for polymer (B1) and copolymerizing the macromonomer (b1) with monomer (b2) will be described. In this case, polymer (B2) has monomer (b2) as a monomer unit.

[0104] [Method of Producing Macromonomer (b1)] Macromonomer (b1) can be produced by known methods. Examples of methods for producing the macromonomer include a method using a cobalt chain transfer agent (U.S. Patent No. 4,680,352), a method using an α-substituted unsaturated compound such as α-bromomethylstyrene as a chain transfer agent (WO 88 / 04304), a method of chemically bonding a polymerizable group (JP-A No. 60-133007, U.S. Patent No. 5,147,952, and JP-A No. 06-298921), and a method using thermal decomposition (JP-A No. 11-240854). Among these, the method for producing macromonomer (b1) is preferably a method using a cobalt chain transfer agent, as it requires fewer production steps and uses a catalyst with a high chain transfer constant.

[0105] Examples of methods for producing the macromonomer (b1) using a cobalt chain transfer agent include bulk polymerization, solution polymerization, and aqueous dispersion polymerization methods such as suspension polymerization and emulsion polymerization. Among these, the aqueous dispersion polymerization method is preferred from the viewpoint of simplifying the recovery step of the macromonomer (b1).

[0106] The cobalt chain transfer agent used in the present invention is represented by the following general formula (2): Examples of the cobalt chain transfer agent that can be used include those described in Japanese Patent No. 3,587,530, JP-A Nos. 6-23209 and 7-35411, U.S. Pat. Nos. 45,269,945, 4,694,054, 4,834,326, 4,886,861, and 5,324,879, International Publication No. 95 / 17435, and Published Japanese Translation of PCT International Publication No. 9-510499.

[0107]

[0108] [In the formula, R １１ ~R １４ are each independently an alkyl group, a cycloalkyl group, or an aryl group. １１ ~X １４ are each independently an F atom, a Cl atom, a Br atom, an OH group, an alkoxy group, an aryloxy group, an alkyl group, or an aryl group.

[0109] Specific examples of cobalt chain transfer agents include bis(borondifluorodimethyldioximinocyclohexane)cobalt(II), bis(borondifluorodimethylglyoximate)cobalt(II), bis(borondifluorodiphenylglyoximate)cobalt(II), cobalt(II) complexes of vicinaliminohydroxyimino compounds, cobalt(II) complexes of tetraazatetraalkylcyclotetradecatetraenes, N,N'-bis(salicylidene)ethylenediaminocobalt(II) complexes, cobalt(II) complexes of dialkyldiazadioxodialkyldodecadienes, and cobalt(II) porphyrin complexes. Among these, bis(borondifluorodiphenylglyoximate)cobalt(II) (R １１ ~R １４ : phenyl group, X １１ ~X １４ : F atom) are preferred. One or more of these can be appropriately selected and used.

[0110] The amount of the cobalt chain transfer agent used is preferably 5 to 350 ppm relative to the monomer used to obtain macromonomer (b1). When the amount of the cobalt chain transfer agent used is 5 ppm or more, the molecular weight is likely to be sufficiently reduced. When the amount of the cobalt chain transfer agent used is 350 ppm or less, the obtained macromonomer (b1) is less likely to be discolored.

[0111] The lower limit of the mass average molecular weight (Mw) of the macromonomer (b1) is preferably 3,000 or more, more preferably 10,000 or more, even more preferably 15,000 or more, and particularly preferably 20,000 or more. If the Mw of the macromonomer (b1) is 3,000 or more, the affinity of the polymer (B1) derived from the macromonomer (b1) with the (meth)acrylic polymer (A) will be good, and miscibility and compatibility can be expected. The upper limit of the mass average molecular weight (Mw) of the macromonomer (b1) is preferably 1,000,000 or less, more preferably 80,000 or less, even more preferably 60,000 or less, and particularly preferably 40,000 or less. If the Mw of the macromonomer (b1) is 1,000,000 or less, the melt viscosity of the (meth)acrylic copolymer (B) will be in an appropriate range. In the present invention, the weight average molecular weight (Mw) of the macromonomer (b1) means a weight average molecular weight that is a relative molecular weight determined using gel permeation chromatography (GPC) and converted into polymethyl methacrylate (PMMA).

[0112] Examples of solvents used when obtaining macromonomer (b1) by solution polymerization include hydrocarbons such as toluene, ethers such as diethyl ether and tetrahydrofuran, halogenated hydrocarbons such as dichloromethane and chloroform, ketones such as acetone, alcohols such as methanol, nitriles such as acetonitrile, vinyl esters such as ethyl acetate, carbonates such as ethylene carbonate, and supercritical carbon dioxide. These may be used alone or in combination of two or more.

[0113] [Method for Producing Macromonomer Copolymer] The method for producing the macromonomer copolymer includes a step of polymerizing a polymerizable mixture containing the polymerizable composition (X) described below and a polymerization initiator.

[0114] The polymerizable composition (X) contains a macromonomer (b1) represented by the following general formula (1) and a comonomer copolymerizable with the macromonomer (b1). The comonomer is appropriately selected from the monomers (b2) that are copolymerizable with the macromonomer (b1).

[0115]

[0116] [In formula (1), R ０ ~R ｎ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group. １ ~X ｎ are each independently a hydrogen atom or a methyl group; Z is a terminal group; and n is a natural number from 1 to 10,000.

[0117] <R ０ ~R ｎ In the formula (1), R ０ ~R ｎ The alkyl group, cycloalkyl group, aryl group or heterocyclic group may have a substituent.

[0118] R ０ ~R ｎ Examples of the alkyl group include branched or linear alkyl groups having 1 to 20 carbon atoms. Specific examples include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and icosyl. Among these, in terms of availability, methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, pentyl, hexyl, heptyl, and octyl are preferred, with methyl, ethyl, n-propyl, i-propyl, n-butyl, and t-butyl being more preferred, and methyl being particularly preferred.

[0119] R ０ ~R ｎExamples of the cycloalkyl group include cycloalkyl groups having 3 to 20 carbon atoms. Specific examples include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a t-butylcyclohexyl group, an isobornyl group, and an adamantyl group. In view of availability, a cyclopropyl group, a cyclobutyl group, and an adamantyl group are preferred.

[0120] R ０ ~R ｎ Examples of the aryl group include aryl groups having 6 to 18 carbon atoms. Specific examples include a phenyl group, a benzyl group, and a naphthyl group.

[0121] R ０ ~R ｎ Examples of the heterocyclic group include heterocyclic groups having 5 to 18 carbon atoms. Specific examples include a γ-lactone group, an ε-caprolactone group, and a morpholine group. Examples of heteroatoms contained in the heterocycle include an oxygen atom, a nitrogen atom, and a sulfur atom.

[0122] R ０ ~R ｎ The substituents of each independently include a group or atom selected from the group consisting of an alkyl group, an aryl group, a carboxy group, an alkoxycarbonyl group (-COOR'), a carbamoyl group (-CONR'R''), a cyano group, a hydroxy group, an amino group, an amide group (-NR'R''), a halogen atom, an allyl group, an epoxy group, an alkoxy group (-OR'), and a group exhibiting hydrophilicity or ionicity. Examples of R' or R'' each independently include R ０ ~R ｎ and the like (excluding heterocyclic groups).

[0123] R ０ ~R ｎ Examples of the alkoxycarbonyl group as a substituent of R include a methoxycarbonyl group. ０ ~R ｎ Examples of the carbamoyl group as a substituent of R include an N-methylcarbamoyl group and an N,N-dimethylcarbamoyl group.０ ~R ｎ Examples of the amide group as a substituent of R include a dimethylamide group. ０ ~R ｎ Examples of the halogen atom as a substituent of R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. ０ ~R ｎ Examples of the alkoxy group as a substituent of R include alkoxy groups having 1 to 12 carbon atoms. A specific example is a methoxy group. ０ ~R ｎ Examples of the hydrophilic or ionic group as a substituent include an alkali salt of a carboxy group or an alkali salt of a sulfoxyl group, a poly(alkylene oxide) group such as a polyethylene oxide group or a polypropylene oxide group, and a cationic substituent such as a quaternary ammonium base.

[0124] R ０ ~R ｎ is preferably at least one selected from an alkyl group and a cycloalkyl group, more preferably an alkyl group. As the alkyl group, a methyl group, an ethyl group, an n-propyl group, or an i-propyl group is preferred, and from the viewpoint of availability, a methyl group is more preferred.

[0125] <X １ ~X ｎ In the formula (1), X １ ~X ｎ From the viewpoint of ease of synthesis of the macromonomer (b1), X １ ~X ｎ Preferably, 80 mol % or more of the total moles of (100 mol %) are methyl groups.

[0126] <Z> In the formula (1), Z is a terminal group of the macromonomer (b1). Examples of the terminal group of the macromonomer (b1) include a hydrogen atom and a group derived from a radical polymerization initiator, similar to terminal groups of polymers obtained by known radical polymerization.

[0127] The lower limit of the content of methyl methacrylate units contained in macromonomer (b1) is not particularly limited. If the content of methyl methacrylate units is 50% by mass or more, relative to 100% by mass of the total mass of macromonomer (b1), this is advantageous for improving impact resistance and transparency. The lower limit of the content of methyl methacrylate units is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more. The upper limit of the content of methyl methacrylate units is not particularly limited. Macromonomer (b1) may be 100% by mass of methyl methacrylate units. The content of methyl methacrylate units may be 99% by mass or less, relative to 100% by mass of the total mass of macromonomer (b1).

[0128] In the method for producing the macromonomer copolymer, the polymerization reaction is preferably carried out using a radical polymerization method. Examples of radical polymerization methods include bulk polymerization methods such as bulk polymerization and cast polymerization; solution polymerization; and aqueous dispersion polymerization methods such as suspension polymerization and emulsion polymerization. Aqueous dispersion polymerization methods such as suspension polymerization and emulsion polymerization are preferred because they can simplify the recovery process of the macromonomer copolymer. Suspension polymerization is more preferred because the resulting polymer particles are easy to handle.

[0129] In the suspension polymerization method, the macromonomer copolymer is obtained as spherical particles with an average particle size of approximately 5 μm to 1 mm. The obtained spherical particles are easy to handle and have little risk of dust scattering when used in processing operations such as extrusion and molding, making them suitable for use as resin compositions. The obtained spherical particles are also preferable because they improve the moldability of the resin composition obtained by the suspension polymerization method. Although the reason for this is unclear, it is thought that trace amounts of abnormal polymers and residual emulsifiers produced in emulsion polymerization can cause foreign matter and thickening, and as a result, suspension polymerization is superior to emulsion polymerization. Details of suspension polymerization will be discussed later.

[0130] The polymerization reaction in the production of the macromonomer copolymer can also be carried out using a bulk polymerization method such as a bulk polymerization method or a cast polymerization method. In this case, a step of heating the polymerizable mixture to polymerize is included. When the polymerization reaction in the production of the macromonomer copolymer is carried out using a solution polymerization method, it is also possible to produce the macromonomer copolymer by producing the macromonomer (b1) by solution polymerization, and then adding the monomer (b2) and a thermal polymerization initiator to the solution as is and carrying out the copolymerization reaction to obtain the macromonomer copolymer.

[0131] In the method for producing a macromonomer copolymer according to the present invention, the polymerizable mixture may contain a sulfur-containing chain transfer agent. Here, the sulfur-containing chain transfer agent refers to a mercaptan compound, such as n-butyl mercaptan or n-octyl mercaptan, that is added as a chain transfer agent to adjust the molecular weight of the copolymer during polymerization. When the polymerizable composition contains a sulfur-containing chain transfer agent, the upper limit of its content is preferably less than 0.01 parts by mass per 100 parts by mass of the polymerizable composition (X). When the upper limit of the sulfur-containing chain transfer agent content is less than 0.01 parts by mass, the composition distribution of the copolymer can be prevented from becoming broad, and the impact resistance of the resulting resin molded article can be improved. While there is no particular lower limit on the content of the sulfur-containing chain transfer agent, it is more preferable that the polymerizable composition does not contain a sulfur-containing chain transfer agent.

[0132] In producing the macromonomer copolymer, polymerization can be carried out so that the mass average molecular weight (Mw) of the resulting macromonomer copolymer is 240,000 or more and 3,500,000 or less. The lower limit of the mass average molecular weight (Mw) of the macromonomer copolymer is preferably 240,000 or more, more preferably 300,000 or more, and even more preferably 600,000 or more. If the Mw of the macromonomer copolymer is 240,000 or more, the flexibility and impact resistance of the resin composition, molding material, and molded article of the present invention are good. The upper limit of the mass average molecular weight (Mw) of the macromonomer copolymer is preferably 3,500,000 or less, more preferably 3,000,000 or less, and even more preferably 2,000,000 or less. If the Mw of the macromonomer copolymer is 3,500,000 or less, the transparency and moldability of the resin composition, molding material, and molded article of the present invention are good. The above upper and lower limits can be combined arbitrarily. In the present invention, the mass average molecular weight (Mw) of the macromonomer copolymer means a mass average molecular weight, which is a relative molecular weight determined by gel permeation chromatography (GPC) in terms of polymethyl methacrylate (PMMA).

[0133] There are no particular limitations on the method for controlling the mass average molecular weight (Mw) of the macromonomer copolymer to 240,000 or more. The Mw of the macromonomer copolymer can be controlled by adjusting the polymerization method, the type and amount of polymerization initiator, the amount of chain transfer agent, the polymerization temperature, etc., according to well-known techniques.

[0134] [Polymerizable composition (X)] The polymerizable composition (X) is one of the raw materials for the (meth)acrylic copolymer (B). The content ratios of the macromonomer (b1) (b1, unit: mass%) and the monomer (b2) (b2, unit: mass%) contained in the polymerizable composition (X), relative to the total mass of the polymerizable composition (X) (100 mass%), are preferably b1:b2 = 35 to 75 mass%: 65 to 25 mass%, more preferably b1:b2 = 40 to 70 mass%: 60 to 30 mass%, even more preferably b1:b2 = 45 to 70 mass%: 55 to 30 mass%, particularly preferably b1:b2 = 50 to 65: 50 to 35 mass%, and most preferably b1:b2 = 55 to 65: 45 to 35 mass%. The ratio of the content of macromonomer (b1) (b1, unit: mass%) to the content of monomer (b2) (b2, unit: mass%) contained in the polymerizable composition (X) is preferably b1:b2=35:65 to 75:25, more preferably b1:b2=40:60 to 70:30, still more preferably b1:b2=45:55 to 70:30 mass%, particularly preferably b1:b2=50:50 to 65:35, and most preferably b1:b2=55:45 to 65:35 mass%. When the lower limit of the content of macromonomer (b1) contained in the polymerizable composition (X) is 35 mass% or more, or the upper limit of the content of monomer (b2) is 65 mass% or less, relative to 100 mass% of the total mass of the polymerizable composition (X), the macromonomer copolymer becomes easy to handle. When the lower limit of the content of the monomer (b2) in the polymerizable composition (X) is 25 mass% or more, or the upper limit of the content of the macromonomer (b1) is 75 mass% or less, relative to 100 mass% of the total mass of the polymerizable composition (X), the impact resistance of the resin composition containing the macromonomer copolymer and the obtained resin molded article can be well maintained.

[0135] [Production of Macromonomer Copolymer by Suspension Polymerization] The case where the polymerization reaction is carried out by the suspension polymerization method will be described in detail below.

[0136] Specific examples of the method for producing a macromonomer copolymer using suspension polymerization include the following methods (1) and (2). (1) A method comprising the following steps i) to v). This method is a method in which the production of the macromonomer (b1) of the present invention and the production of the macromonomer copolymer are carried out separately. (2) A method in which, of the following steps i) to v), the production of the macromonomer (b1) of the present invention and the production of the macromonomer copolymer of the present invention are carried out continuously, instead of the following steps i) to iii).

[0137] i) Syrup Preparation Step A syrup is prepared by dissolving the bead-like macromonomer (b1) produced by suspension polymerization in a solution containing the monomer (b2), and this is used as the polymerizable composition (X).

[0138] When preparing the polymerizable composition (X), a mixture containing the macromonomer (b1) and the monomer (b2) can be heated at a temperature equal to or lower than the boiling point of the monomer (b2) to promote dissolution of the macromonomer (b1). The temperature at which the polymerizable composition (X) is prepared is preferably in the range of 20°C to 100°C, more preferably in the range of 40°C to 80°C. If the radical polymerization initiator used does not react at the temperature at which the polymerizable composition (X) is prepared, the radical polymerization initiator can be mixed with the polymerizable composition (X) to obtain a polymerizable mixture, and then the polymerizable mixture can be heated.

[0139]

[0033] ii) Radical Polymerization Initiator Dissolving Step: When the radical polymerization initiator reacts at the temperature at which the polymerizable composition (X) obtained in step i) is prepared, the polymerizable composition (X) is once cooled to room temperature or below, and then the radical polymerization initiator is added and dissolved uniformly to obtain a polymerizable mixture. The temperature of the polymerizable composition (X) when the radical polymerization initiator is added is preferably not more than a temperature obtained by subtracting 15°C from the 10-hour half-life temperature of the radical polymerization initiator.

[0140] iii) Step of Preparing an Aqueous Solution: The polymerizable mixture and the aqueous solution are mixed and then stirred to prepare a suspension in which droplets of the polymerizable mixture are dispersed in the aqueous solution. The aqueous solution is an aqueous solution for dispersing the polymerizable mixture, and may contain a dispersant, an electrolyte, and other auxiliary agents. By appropriately selecting the combination of the dispersant and the electrolyte, it is possible to control the dispersibility of the droplets of the polymerizable mixture formed in the aqueous solution when the polymerizable mixture is dispersed in the aqueous solution.

[0141] The water used in the aqueous solution is preferably deionized water, since this improves the dispersibility of the droplets of the polymerizable mixture.

[0142] Examples of dispersants include alkali metal salts of poly(meth)acrylic acid, copolymers of alkali metal salts of (meth)acrylic acid and (meth)acrylic acid esters, copolymers of alkali metal salts of sulfoalkyl (meth)acrylate and (meth)acrylic acid esters, alkali metal salts of polystyrene sulfonates, copolymers of alkali metal salts of styrene sulfonates and (meth)acrylic acid esters, or copolymers consisting of combinations of these monomers; polyvinyl alcohol with a saponification degree of 70 to 100%, methyl cellulose, starch, and hydroxyapatite. These may be used alone or in combination of two or more. Among these, copolymers of alkali metal salts of sulfoalkyl (meth)acrylate and (meth)acrylic acid esters and copolymers of alkali metal salts of (meth)acrylic acid and (meth)acrylic acid esters are preferred, as they exhibit good dispersion stability during suspension polymerization. The dispersant is used, for example, in an amount of 0.0005 to 0.5 parts by mass per 100 parts by mass of the polymerizable composition (X).

[0143] Examples of the electrolyte include sodium carbonate, sodium sulfate, manganese sulfate, etc. The electrolyte is used in an amount of, for example, 0.01 to 1.0 part by mass per 100 parts by mass of the polymerizable composition (X).

[0144] I) Syrup Preparation Step: A solution containing a monomer (b2) is added to a bead-like macromonomer (b1) produced by suspension polymerization dispersed in an aqueous solution to prepare a polymerizable composition (X). The temperature at which the macromonomer (b1) is dissolved in the solution containing the monomer (b2) is preferably in the range of 20°C to 100°C, more preferably in the range of 40°C to 90°C, and even more preferably in the range of 50°C to 80°C. The aqueous solution can be the same as that described in iii) above.

[0145] II) Radical Polymerization Initiator Dissolving Step When the radical polymerization initiator reacts at the temperature at which the polymerizable composition (X) obtained in step I) is prepared, the polymerizable composition (X) is once cooled to room temperature or below, and then the radical polymerization initiator is added and dissolved uniformly to obtain a polymerizable mixture. The temperature of the polymerizable composition (X) when the radical polymerization initiator is added is preferably not more than a temperature obtained by subtracting 15°C from the 10-hour half-life temperature of the radical polymerization initiator.

[0146] When the polymerization reaction is carried out in the presence of a radical polymerization initiator, known organic peroxides such as 2,4-dichlorobenzoyl peroxide and t-butyl peroxypivalate, and known azo compounds such as 2,2'-azobisisobutyronitrile and 2,2'-azobis(2,4-dimethylvaleronitrile) can be used as the radical polymerization initiator. The amount of the radical polymerization initiator to be added can be appropriately selected by a person skilled in the art in accordance with well-known techniques. Typically, the amount of the radical polymerization initiator to be added is 0.0001 to 10 parts by mass per 100 parts by mass of the total amount of the polymerizable composition (X).

[0147] iv) Polymerization Reaction Step Next, the obtained suspension is heated while stirring to initiate the polymerization reaction. It is preferable to remove dissolved oxygen from the polymerizable mixture and the aqueous solution before heating by subjecting them to reduced pressure degassing or nitrogen substitution. The polymerization temperature during the polymerization reaction is an important condition for obtaining a macromonomer copolymer in a high yield. The polymerization temperature here refers to the temperature of the suspension. The polymerization temperature is preferably 50°C to 90°C, more preferably 60°C to 85°C, and even more preferably 65°C to 80°C. If the polymerization temperature is too low, there is a concern that the reaction will proceed slowly and the polymerization time will be long. If the polymerization temperature is too high, cleavage of the adduct radical, which is a reaction intermediate, will take precedence, tending to reduce the yield of the macromonomer copolymer.

[0148] In the latter stage of the polymerization reaction, the suspension may be heated to increase the reaction rate of the polymerizable composition (X) and to eliminate unreacted radical polymerization initiator. The temperature to which the suspension is heated is preferably 80° C. or higher, more preferably 85° C. or higher. The temperature-raising time may be determined by calculating the time required for the radical polymerization initiator to disappear, and is usually about 30 minutes to 2 hours.

[0149] v) Recovery Step After the above step, the suspension is cooled to room temperature or below, and the resulting copolymer in the form of beads is recovered by a known method such as filtration. If necessary, a washing step for removing impurities such as dispersants and electrolytes, a step for removing beads containing air bubbles, a drying step, etc. may be performed. The finally obtained macromonomer copolymer in the form of beads is referred to as the (meth)acrylic copolymer (B) of the present invention.

[0150] [Core-shell rubber (C)] The resin composition of the present invention may contain a core-shell rubber (C) as needed. The core-shell rubber (C) is a component different from the (meth)acrylic copolymer (B). The core-shell rubber (C) is a particulate rubber containing a core made of a rubber component and a shell component having functions such as compatibility with the matrix. The core-shell rubber (C) is used for the purpose of imparting flexibility and impact resistance to the resin composition, molding material, resin molded product, and film of the present invention.

[0151] The core-shell rubber (C) can be appropriately selected from commonly available rubbers. Examples of the core of the core-shell rubber include acrylic rubber containing acrylate as a repeating unit, butadiene rubber containing butadiene as a repeating unit, butadiene-acrylic composite rubber containing butadiene and acrylate as repeating units, and silicone-acrylic composite rubber containing dimethylsiloxane and acrylate as repeating units.

[0152] Among these, it is preferable that the refractive index of the core is close to that of the (meth)acrylic polymer (A), since this improves the transparency of the resin composition. From the viewpoint of refractive index, the core is preferably an acrylic rubber containing acrylate as a repeating unit, or a butadiene-acrylic composite rubber containing butadiene and acrylate as repeating units. From the viewpoint of improving the weather resistance of the resin composition, the core is preferably an acrylic rubber or a silicone-acrylic composite rubber containing dimethylsiloxane and acrylate as repeating units. From the viewpoint of improving toughness and impact resistance, the core is preferably a butadiene rubber containing butadiene as a repeating unit, a butadiene-acrylic composite rubber containing butadiene and acrylate as repeating units, or a silicone-acrylic composite rubber containing dimethylsiloxane and acrylate as repeating units. The type of core can be appropriately selected and used depending on the required performance of the resin molded product and film. Multiple core-shell rubbers with different core types may be used in combination.

[0153] The core-shell rubber (C) is not particularly limited, but preferably has a multi-layer structure of three or more layers including an inner layer, an intermediate layer, and a graft layer.

[0154] The average particle diameter of the core-shell rubber (C) is preferably 50 nm or more, more preferably 100 nm or more, and even more preferably 200 nm or more. The average particle diameter of the core-shell rubber (C) is preferably 1000 nm or less, more preferably 700 nm or less, and even more preferably 500 nm or less. If the average particle diameter is 50 nm or more, it functions as a rubber and can improve toughness and impact resistance. If the average particle diameter is 1000 nm or less, the number of particles increases, resulting in good toughness and impact resistance.

[0155] The core-shell rubber (C) is preferably used in a small amount because it causes foreign matter defects during the production of extruded films. When the core-shell rubber (C) is used, it is preferably used in an amount of 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, relative to 100% by mass of the total resin composition of the present invention. It is most preferable not to use the core-shell rubber (C).

[0156] [Anti-blocking agent (D)] When a film is produced using the resin composition of the present invention, it is preferable to add an anti-blocking agent (D) to prevent blocking during winding of the film. The anti-blocking agent (D) is also called an anti-blocking agent (AB agent) or a lubricant. Various commonly available anti-blocking agents can be used as the anti-blocking agent.

[0157] Various resin particles and inorganic particles can be used as the antiblocking agent (D). Examples of resin particles include acrylic particles, polystyrene particles, polyester particles, silicone fine particles, and polyvinyl chloride particles. Examples of inorganic particles include colloidal silica, fumed silica, zeolite, acicular silica, talc, aluminum oxide, and mineral powder.

[0158] Among these, it is preferable to use acrylic particles because the resin composition of the present invention contains the (meth)acrylic polymer (A). By selecting acrylic particles, the difference in refractive index between the resin composition of the present invention and the acrylic particles becomes small, and a resin molded product and a film having excellent transparency can be obtained.

[0159] The acrylic particles are preferably crosslinked so that the antiblocking agent maintains its particle shape when the resin composition is melt-kneaded. Furthermore, in order to prevent resin clogging, pressure loss, filter clogging, etc. during melt-kneading or melt-molding, the antiblocking agent preferably does not contain large particles. For these reasons, it is preferable to use crosslinked acrylic particles with a small particle size and few coarse particles as the antiblocking agent (D). It is preferable to use monodisperse crosslinked acrylic particles because they contain few coarse particles.

[0160] The average particle size of the antiblocking agent (D) is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 2 μm or less, and most preferably 1 μm or less. If the average particle size of the antiblocking agent (D) is 10 μm or less, antiblocking performance can be exhibited with a small amount added, and the effect on transparency can be minimized. The average particle size of the antiblocking agent (D) is preferably 10 nm or more, preferably 50 nm or more, and preferably 100 nm or more. If the average particle size of the antiblocking agent (D) is 10 nm or more, antiblocking performance can be exhibited.

[0161] The amount of the antiblocking agent added is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, relative to 100% by mass of the total resin composition of the present invention. When the amount of the antiblocking agent (D) added is 0.01% by mass or more, antiblocking performance can be exhibited. The amount of the antiblocking agent (D) added is preferably 2% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, relative to 100% by mass of the total resin composition of the present invention. When the amount of the antiblocking agent (D) added is 2% by mass or less, adverse effects such as a decrease in transparency can be suppressed.

[0162] [Other Components] The resin composition of the present invention may contain other components in addition to the (meth)acrylic polymer (A), the (meth)acrylic copolymer (B), the core-shell rubber (C), and the antiblocking agent (D).

[0163] Other components are added to the resin composition as needed. Examples of other components include release agents, antioxidants, heat stabilizers, impact modifiers, flexibility modifiers, weather resistance modifiers, colorants, inorganic pigments, organic pigments, carbon black, ferrite, conductivity modifiers, ultraviolet absorbers, infrared absorbers, inorganic fillers, reinforcing agents, plasticizers, antiplasticizers, neutralizing agents, crosslinking agents, flame retardants, preservatives, insect repellents, fragrances, radical scavengers, and sound absorbing materials. These other components may be used alone or in combination of two or more.

[0164] [Method for producing resin composition and molding material] The resin composition of the present invention can be produced by mixing raw materials according to a conventional method, and the method is not particularly limited. Examples of the mixing method include a method in which the raw materials are placed in a single-screw extruder or a twin-screw extruder and heated, melt-kneaded at about 220 to 280°C. The resin composition of the present invention can be processed into pellets after heated, melt-kneaded, and then suitably used as a molding material, for example, a film molding material, particularly an extruded film molding material.

[0165] [Resin Molded Article] The resin composition and molding material of the present invention are shaped into a resin molded article by a known melt molding method such as extrusion molding, injection molding, compression molding, blow molding, etc. The shape of the resin molded article of the present invention is not particularly limited, and examples thereof include a film shape, a sheet shape, a plate shape, a substantially box-like shape, and a three-dimensional shape having a curved surface.

[0166] [Uses of Resin Molded Articles] The resin molded article of the present invention has flexibility that allows it to be handled as a film and excellent transparency over a wide temperature range. Therefore, the resin molded article of the present invention can be suitably used for display front panels such as liquid crystal and organic electroluminescence displays, signage, lighting, home appliances, vehicle interior and exterior materials, industrial materials, construction materials, lenses, light guide plates, light collecting members, and optical films used in liquid crystal and organic electroluminescence displays. For example, resin molded articles obtained by molding the molding material of the present invention include polarizing plate protective films and polarizing plates. The resin molded article of the present invention is useful as a component of these image display devices.

[0167] The present invention will be described in more detail below with reference to examples and comparative examples. The present invention is not limited to the following examples. In the following, "parts" means "parts by mass."

[0168] [Evaluation Method] Evaluations in the examples and comparative examples were carried out by the following methods.

[0169] (Weight-average molecular weight (Mw) and number-average molecular weight (Mn) of macromonomer (b1)) The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the macromonomer (b1) obtained in the examples and comparative examples were measured using gel permeation chromatography (GPC). 10 mg of the obtained copolymer was dissolved in 10 mL of tetrahydrofuran, and the solution was filtered through a 0.45 μm filter to prepare a sample for GPC measurement. For the measurement, a gel permeation chromatography measuring device (manufactured by Tosoh Corporation, model name: HLC-8320) was used, to which a polymer measurement guard column (manufactured by Tosoh Corporation, product name: TSK-GUARD COLUMN SUPER H-H) and two polymer measurement columns (manufactured by Tosoh Corporation, product name: TSK-GEL SUPER HM-H) were connected in series. A differential refractometer (RI) was used as a detector. Measurements were performed under the following conditions: separation column temperature: 40°C, mobile phase: tetrahydrofuran, mobile phase flow rate: 0.6 mL / min, sample injection volume: 10 μL. A calibration curve was created using several types of polymethyl methacrylate with known molecular weights (manufactured by Polymer Laboratories, peak molecular weight (Mp) 1,560 to 19,500,000) as standard polymers, and the relative molecular weights Mw and Mn in terms of polymethyl methacrylate were determined.

[0170] (Mass Average Molecular Weight (Mw) and Number Average Molecular Weight (Mn) of Macromonomer Copolymer) The mass average molecular weight (Mw) and number average molecular weight (Mn) of the macromonomer copolymer, which is the (meth)acrylic copolymer (B) obtained in the Examples and Comparative Examples, were measured using gel permeation chromatography (GPC). 10 mg of the obtained copolymer was dissolved in 10 mL of tetrahydrofuran, and the solution filtered through a 0.45 μm filter was used as a sample for GPC measurement. For the measurement, a high-performance liquid chromatography measurement device (manufactured by Tosoh Corporation, model name: HLC-8320) was used, connected in series with a polymer measurement guard column (manufactured by Tosoh Corporation, product name: TSK-GUARD COLUMN SUPER H-H) and one ultra polymer measurement column (manufactured by Tosoh Corporation, product name: TSK-GEL GMHHR-H). A differential refractometer (RI) was used as the detector. Measurements were performed under the following conditions: separation column temperature: 40°C, mobile phase: tetrahydrofuran, mobile phase flow rate: 0.6 mL / min, sample injection volume: 10 μL. A calibration curve was created using several types of polymethyl methacrylate with known molecular weights (manufactured by Polymer Laboratories, peak molecular weight (Mp) 1,560 to 19,500,000) as standard polymers, and the relative molecular weights Mw and Mn in terms of polymethyl methacrylate were determined.

[0171] (Film Handling Efficiency: Evaluation of Cutter Resistance) The extruded films obtained in the Examples and Comparative Examples were cut with scissors, and then a cutter (manufactured by Olfa, product name: Type A) was used to run a blade through the film, and the film was evaluated as follows based on how well it ran. The angle of the blade relative to the film was adjusted to about 45° to 60°. ⊚: Measured 10 times, and the blade could be run 9 or more times. ○: Measured 10 times, and the blade could be run 5 to less than 9 times. ×: Measured 10 times, and the blade could be run less than 5 times. Or the blade could not be run.

[0172] (Other film evaluations: film surface smoothness) Fluorescent light was reflected indoors onto the extruded films obtained in the Examples and Comparative Examples, and surface smoothness was judged based on whether the image of the fluorescent light reflected on the film looked clear. ○: No fine irregularities, and the edge of the fluorescent light looked straight. △: Fine irregularities were slightly visible, and the edge of the fluorescent light looked a little irregular. ×: Fine irregularities were present, and the edge of the fluorescent light looked irregular.

[0173] (Other Film Evaluations: Anti-blocking Property) Two extruded films obtained in Examples and Comparative Examples were stacked and rubbed together, and the ease of film movement was evaluated. ○: Film moves ×: Film does not move

[0174] [Raw Materials] The abbreviations for the compounds used in the Examples and Comparative Examples are as follows: MMA: methyl methacrylate (manufactured by Mitsubishi Chemical Corporation) MA: methyl acrylate (manufactured by Mitsubishi Chemical Corporation) BA: n-butyl acrylate (manufactured by Mitsubishi Chemical Corporation) ST: styrene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Dispersant (1): dispersant produced in Production Example 1 Chain transfer agent (1): chain transfer catalyst produced in Production Example 2 Polymerization initiator (1): 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate (manufactured by NOF Corporation, trade name: Perocta O) Polymerization initiator (2): 2,2'-azobis(2-methylbutyronitrile) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: V-59) (Meth)acrylic polymer (A1-1): a (meth)acrylic polymer containing 90% by mass or more of methyl methacrylate units, mass average molecular weight: 140,000, MFR: 1.0 g / 10 min or less (230°C, 37.3N); (meth)acrylic polymer (A1-2): a (meth)acrylic polymer containing 90% by mass or more of methyl methacrylate units, mass average molecular weight: 150,000, MFR: 1.0 g / 10 min or less (230°C, 37.3N); (meth)acrylic polymer (A1-3): a (meth)acrylic polymer containing 90% by mass or more of methyl methacrylate units, mass average molecular weight: 170,000, MFR: 1.0 g / 10 min or less (230°C, 37.3N). (Meth)acrylic polymer (A2-1): (meth)acrylic polymer containing 80% by mass or more of methyl methacrylate units, mass average molecular weight: 100,000, MFR: 14 g / 10 min (230°C, 37.3N) (meth)acrylic polymer (A-1): (meth)acrylic polymer containing 95% by mass or more of methyl methacrylate units, mass average molecular weight: 100,000, MFR: 2 g / 10 min (230°C, 37.3N) (meth)acrylic polymer (A-2): (meth)acrylic polymer containing 90% by mass or more of methyl methacrylate units, mass average molecular weight: 120,000, MFR: 14 g / 10 min (230°C, 37.3N) Antiblocking agent (D) (MX-80H3wT): trade name, manufactured by Soken Chemical & Engineering Co., Ltd., crosslinked acrylic monodisperse particles, average particle size: 0.8 μm

[0175] [Production Example 1: Synthesis of Dispersant (1)] In a reactor equipped with a stirrer, a cooling tube, and a thermometer, 61.6 parts of a 17% by mass aqueous potassium hydroxide solution, 19.1 parts of MMA, and 19.3 parts of deionized water were charged. Next, the liquid in the reactor was stirred at room temperature, and after confirming the exothermic peak, the mixture was stirred for 4 hours. After this, the reaction liquid in the reactor was cooled to room temperature to obtain an aqueous potassium methacrylate solution.

[0176] Next, 900 parts of deionized water, 70 parts of a 42% by weight aqueous solution of sodium 2-sulfoethyl methacrylate (manufactured by Mitsubishi Chemical Corporation, trade name: Acryester SEM-Na), 16 parts of the above potassium methacrylate aqueous solution, and 7 parts of MMA were placed in a polymerization apparatus equipped with a stirrer, a condenser, and a thermometer, and the mixture was stirred. While the atmosphere inside the polymerization apparatus was replaced with nitrogen, the liquid in the reaction apparatus was heated to 50°C. 0.053 parts of V-50 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: 2,2'-azobis(2-methylpropionamidine) dihydrochloride) was added as a polymerization initiator to the polymerization apparatus, and the liquid in the reaction apparatus was heated to 60°C. After the addition of the polymerization initiator, 1.4 parts of MMA was added in 5 installments every 15 minutes (total amount of MMA: 7 parts). Thereafter, the liquid in the polymerization reactor was kept at 60° C. for 6 hours while stirring, and then cooled to room temperature to obtain a dispersant (1) in the form of a transparent aqueous solution having a solid content of 8% by mass.

[0177] Production Example 2 Synthesis of Chain Transfer Agent (1) In a synthesis apparatus equipped with a stirrer, 2.00 g (8.03 mmol) of cobalt(II) acetate tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., Wako Special Grade), 3.86 g (16.1 mmol) of diphenylglyoxime (manufactured by Tokyo Chemical Industry Co., Ltd., EP Grade), and 100 mL of diethyl ether that had been deoxygenated in advance by nitrogen bubbling were placed under a nitrogen atmosphere, and the mixture was stirred at room temperature for 2 hours.

[0178] Next, 20 mL of boron trifluoride diethyl ether complex (manufactured by Tokyo Chemical Industry Co., Ltd., EP grade) was added, and the mixture was stirred for an additional 6 hours. The resulting mixture was filtered. The filtered solid was washed with diethyl ether and dried at 100 MPa or less and 20°C for 12 hours, yielding 5.02 g (7.93 mmol, yield 99% by mass) of chain transfer agent (1) as a brown solid.

[0179] [Production Example 3: Synthesis of Macromonomer (b1)] In a polymerization apparatus equipped with a stirrer, a condenser, and a thermometer, 145 parts of deionized water, sodium sulfate (Na ２ SO ４ 0.1 parts by mass of dispersant (1) (solid content 8% by mass) produced in Production Example 1 and 0.26 parts by mass of dispersant (1) (solid content 8% by mass) produced in Production Example 1 were added and stirred to prepare a uniform aqueous solution. Next, 95 parts by mass of MMA, 5.0 parts by mass of MA, 0.0014 parts by mass of chain transfer agent (1) produced in Production Example 2, and 0.25 parts by mass of polymerization initiator (1) were added to prepare an aqueous dispersion.

[0180] Next, the inside of the polymerization apparatus was thoroughly purged with nitrogen, and the aqueous dispersion was heated to 80°C and maintained there for 3 hours, and then heated to 90°C and maintained there for 2 hours. The reaction solution was then cooled to 40°C to obtain an aqueous suspension of a macromonomer. This aqueous suspension was filtered through a filter cloth. The residue was washed with deionized water and dried at 40°C for 16 hours to obtain a bead-like macromonomer (b1). The obtained macromonomer (b1) had a number average molecular weight (Mn) of 21,300 and a mass average molecular weight (Mw) of 39,100. The Tg of the homopolymer of methyl methacrylate (MMA) is 105°C (POLYMER HANDBOOK FOURTH EDITION 2003), and the Tg of the homopolymer of methyl acrylate (MA) is 10°C (POLYMER HANDBOOK FOURTH EDITION 2003). The Tg of the macromonomer (b1) was calculated to be 99°C using the Fox equation.

[0181] [Production Example 4: (Meth)acrylic Copolymer (B)] In a polymerization apparatus equipped with a stirrer, a cooling tube, and a thermometer, 60 parts of the macromonomer (b1) obtained in Production Example 3, 150 parts of deionized water, 0.26 parts of dispersant (1), and 0.3 parts of sodium sulfate were added and stirred to obtain an aqueous suspension. Next, the temperature inside the polymerization apparatus was raised to 70 ° C, and 33.2 parts of BA and 6.8 parts of ST were slowly added. Then, the mixture was stirred for 1 hour at 70 ° C to dissolve the macromonomer (b1) in BA and ST, obtaining a dispersion. Next, the polymerization apparatus was cooled to 40 ° C, and 0.5 parts of polymerization initiator (2) was added and stirred for 30 minutes to dissolve. Next, the atmosphere inside the polymerization apparatus was thoroughly purged with nitrogen, and the aqueous dispersion was heated to 82 ° C and held for 4 hours, then heated to 90 ° C and held for 1 hour. After that, the mixture was cooled to 40 ° C or below, filtered through a filter cloth, and the filtrate was washed with deionized water. The water-washed filtrate was dried at 40°C for 12 hours using a hot air circulation dryer to obtain a bead-shaped macromonomer copolymer, (meth)acrylic copolymer (B). The obtained (meth)acrylic copolymer (B) had a number average molecular weight (Mn) of 75,000 and a mass average molecular weight (Mw) of 1,300,000. The Tg of the homopolymer of styrene (ST) was 100°C (POLYMER HANDBOOK FOURTH EDITION 2003), and the Tg of the homopolymer of n-butyl acrylate (BA) was -54°C (POLYMER HANDBOOK FOURTH EDITION 2003). The Tg of the polymer (B2) contained in the (meth)acrylic copolymer (B) was -37.5°C when calculated using the Fox equation.

[0182] Example 1 A pellet-shaped resin composition was prepared using a twin-screw extruder manufactured by Shibaura Machine Co., Ltd. (product name: TEM-26SX, 26 mmφ, L / D≈48). Seventy parts of (A1-1) were used as the (meth)acrylic polymer (A1) and 30 parts of the (meth)acrylic copolymer (B) obtained in Production Example 4. These were melt-kneaded using a 26 mmφ screw-type twin-screw extruder (manufactured by Shibaura Machine Co., Ltd., model name: TEM-26SX) at a cylinder temperature of 200 to 230°C and a die temperature of 230°C to obtain a pellet-shaped resin composition (molding material). The resulting resin composition pellets were used to form a film at 240°C using a single-screw extruder (manufactured by GM Engineering Co., Ltd., GM30-35) equipped with a T-die to produce an extruded film with a thickness of 50 μm. This extruded film was then evaluated as described above. The evaluation results are shown in Table 1.

[0183] [Examples 2 to 5, Comparative Examples 1 and 2] Pellet-shaped resin compositions were prepared using the resin compositions shown in Table 1, and films were produced by extrusion molding and evaluated in the same manner as in Example 1. The blending compositions of the resin compositions and the evaluation results of the obtained films are shown in Table 1.

[0184]

[0185] Comparing Examples 1 to 5 with Comparative Examples 1 and 2, it can be seen that in Examples 1 to 5, the (meth)acrylic polymer (A), which is a random copolymer and / or homopolymer, contains 50% by mass or more of methyl methacrylate units and contains a (meth)acrylic polymer (A1) having a polystyrene-equivalent weight average molecular weight of more than 130,000 as determined by gel permeation chromatography (GPC), thereby improving cutter resistance and providing excellent film handleability. In particular, Examples 4 and 5, which used a (meth)acrylic polymer (A1) with a high weight average molecular weight, showed very good cutter resistance. However, the (meth)acrylic polymers (A1-1), (A1-2), and (A1-3) used as the (meth)acrylic polymer (A1) in Examples 1 to 5 had low fluidity and could not be melt-molded into films by themselves. Combining the (meth)acrylic polymer (A1) with the (meth)acrylic copolymer (B) enabled melt-molding of films with good cutter resistance. Furthermore, Examples 2 to 5 show that the inclusion of the (meth)acrylic polymer (A2) improves the surface smoothness of the resulting film, and Examples 3 to 5 show that the inclusion of the antiblocking agent (D) also provides an antiblocking effect.

[0186] The resin composition and molding material of the present invention contain, as constituent components, a (meth)acrylic polymer (A1) and a (meth)acrylic copolymer (B). The resin molded article of the present invention is obtained by molding the molding material, and therefore, a film having good handleability and good surface smoothness can be obtained.

[0187] Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the present invention. This application is based on Japanese Patent Application No. 2023-151439, filed on September 19, 2023, and is incorporated by reference in its entirety.

Claims

1. A resin composition comprising a (meth)acrylic polymer (A) which is a random copolymer and / or a homopolymer, and a (meth)acrylic copolymer (B) which is a block copolymer and / or a graft copolymer, wherein the (meth)acrylic polymer (A) contains 50% by mass or more of repeating units derived from methyl methacrylate, the (meth)acrylic polymer (A) contains a (meth)acrylic polymer (A1) having a polystyrene-equivalent mass average molecular weight of more than 130,000 as determined by gel permeation chromatography (GPC), the (meth)acrylic copolymer (B) is a polymer containing a polymer (B1) and a polymer (B2) in the same molecule, the polymer (B1) is a polymer containing 50% by mass or more of units derived from methyl methacrylate and having a glass transition temperature higher than 0°C, and the polymer (B2) is a polymer having a glass transition temperature of 0°C or lower.

2. The resin composition according to claim 1, wherein the (meth)acrylic polymer (A) further comprises a (meth)acrylic polymer (A2), the (meth)acrylic polymer (A2) has a melt flow rate of 7.0 g / 10 min or more under conditions of 230°C and 37.3 N in accordance with JIS K7210 or ISO 1133, and the (meth)acrylic polymer (A2) is contained in an amount of 3 to 15 mass% relative to a total of 100 mass% of the resin composition.

3. The resin composition according to claim 1, wherein the (meth)acrylic polymer (A1) has a melt flow rate of less than 7.0 g / 10 min at 230° C. and 37.3 N according to JIS K7210 or ISO 1133.

4. The resin composition according to claim 1, comprising 15% by mass or more of the (meth)acrylic copolymer (B) relative to 100% by mass of the total of the resin composition.

5. The resin composition according to claim 1, wherein the (meth)acrylic copolymer (B) has a mass average molecular weight of more than 300,000.

6. The resin composition according to claim 1, wherein the (meth)acrylic copolymer (B) contains a repeating unit derived from a macromonomer (b1) represented by the following general formula (1): [In formula (1), R ０ ~R ｎ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group. １ ~X ｎ are each independently a hydrogen atom or a methyl group; Z is a terminal group; and n is a natural number from 1 to 10,000.

7. A molding material comprising the resin composition according to any one of claims 1 to 6.

8. The molding material according to claim 7, which is a film molding material.

9. The molding material according to claim 7, which is a molding material for extrusion film.

10. A resin molded product obtained by molding the molding material according to claim 7.

11. An optical film obtained by molding the molding material according to claim 7.

12. A polarizing plate protective film obtained by molding the molding material according to claim 7.

13. A polarizing plate comprising the resin molded article according to claim 10.

14. An image display device comprising the resin molded article according to claim 10.

15. A method for producing a resin composition by mixing a (meth)acrylic polymer (A) which is a random copolymer and / or a homopolymer, and a (meth)acrylic copolymer (B) which is a block copolymer and / or a graft copolymer, characterized in that the (meth)acrylic polymer (A) contains 50% by mass or more of repeating units derived from methyl methacrylate, the (meth)acrylic polymer (A) contains a (meth)acrylic polymer (A1) having a polystyrene-equivalent mass average molecular weight determined by gel permeation chromatography (GPC) measurement of more than 130,000, the (meth)acrylic copolymer (B) is a polymer containing a polymer (B1) and a polymer (B2) in the same molecule, the polymer (B1) is a polymer containing 50% by mass or more of units derived from methyl methacrylate and having a glass transition temperature higher than 0°C, and the polymer (B2) is a polymer having a glass transition temperature of 0°C or lower.

16. The method for producing a resin composition according to claim 15, wherein the (meth)acrylic polymer (A) further comprises a (meth)acrylic polymer (A2), the (meth)acrylic polymer (A2) has a melt flow rate of 7.0 g / 10 min or more under conditions of 230°C and 37.3 N in accordance with JIS K7210 or ISO 1133, and the (meth)acrylic polymer (A2) is contained in an amount of 3 to 15 mass% relative to a total of 100 mass% of the resin composition.

17. A method for producing a resin composition according to claim 15, wherein the (meth)acrylic polymer (A1) has a melt flow rate of less than 7.0 g / 10 min under conditions of 230°C and 37.3 N in accordance with JIS K7210 or ISO 1133.

18. The method for producing a resin composition according to claim 15, wherein the (meth)acrylic copolymer (B) is contained in an amount of 15% by mass or more relative to 100% by mass of the total of the resin composition.

19. The method for producing a resin composition according to claim 15, wherein the (meth)acrylic copolymer (B) has a mass average molecular weight of more than 300,000.

20. A method for producing a resin composition according to claim 15, wherein the (meth)acrylic copolymer (B) contains a repeating unit derived from a macromonomer (b1) represented by the following general formula (1): [In formula (1), R ０ ~R ｎ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group. １ ~X ｎ are each independently a hydrogen atom or a methyl group; Z is a terminal group; and n is a natural number from 1 to 10,000.

21. A method for producing a resin molded article, comprising producing a resin composition by the method for producing a resin composition according to any one of claims 15 to 20, and molding a molding material containing the resin composition.

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