Resin composition, molding material, and molded body

Abstract

Disclosed is a resin composition which contains a (meth)acrylic polymer (A), a (meth)acrylic copolymer (B), and a rubbery graft polymer (C) that has a crosslinked structure and / or a (meth)acrylic polymer (D), wherein: the (meth)acrylic polymer (A) is a random copolymer and / or a homopolymer and contains 50% by mass or more of a repeating unit that is derived from methyl methacrylate; the (meth)acrylic copolymer (B) is a block copolymer and / or a graft copolymer; and the (meth)acrylic polymer (D) is a random copolymer and / or a homopolymer, contains 50% by mass or more of a repeating unit that is derived from methyl methacrylate, and has a mass average molecular weight of 500,000 or more.

Description

Resin composition, molding material, and molded body

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

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

[0003] Some of these applications require acrylic resin products to be endowed with flexibility, toughness, and impact resistance, and there is also a demand for acrylic resins with excellent melt-moldability, which allows them to be molded into thin or complex shapes using melt-molding methods such as injection molding and extrusion molding.

[0004] As a technology for improving the impact resistance of acrylic resins, for example, Patent Document 1 discloses a resin composition in which a rubber (core-shell rubber) having a core-shell structure, which has a core made of crosslinked rubber and a shell that ensures compatibility and dispersibility with the (meth)acrylic polymer that forms the matrix, is blended with a (meth)acrylic resin. However, the resin composition described in Patent Document 1 tends to have an increased melt viscosity due to the inclusion of the core-shell rubber, resulting in a decrease in melt moldability. This has resulted in the problem that the use of the resin composition is limited to resin products with large thicknesses or simple shapes.

[0005] A known technique for improving the melt moldability of acrylic resins is to use resin compositions containing block copolymers and / or graft copolymers in combination with (meth)acrylic resins. In block copolymers and / or graft copolymers, two or more polymer segments are chemically bonded to one another. Therefore, the phase-separated structure of resin compositions containing block copolymers and / or graft copolymers with poly(meth)acrylate chains in combination with acrylic resins is nanometer-sized (referred to as a "microphase-separated structure"). Therefore, in such resin compositions and molded articles obtained by molding the resin compositions, it is possible to simultaneously develop the properties of both the acrylic resin matrix and the block copolymer and / or graft copolymer. Furthermore, it is also possible to develop the properties of each polymer segment of the block copolymer and / or graft copolymer.

[0006] A resin composition containing the block copolymer and / or graft copolymer in an acrylic resin forms a microphase-separated structure, and therefore, a 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.

[0007] As a technique for improving the impact resistance of acrylic resins using block copolymers, for example, Patent Document 2 describes a method for obtaining a block copolymer by controlled radical polymerization in the presence of nitroxide. Specifically, the 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 also describes that the obtained sheet-like molded article contains a (meth)acrylic polymer and a block copolymer having a polymethyl methacrylate chain and an n-butyl acrylate-styrene copolymer chain, and has excellent impact resistance and transparency.

[0008] 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 "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 acrylic macromonomers using a cobalt complex. A macromonomer is a polymer having a polymerizable functional group in its molecular structure, and is sometimes called a macromer.

[0009] Patent Document 3 discloses a technology in which a macromonomer is produced by CCTP, a macromonomer copolymer is produced using the obtained macromonomer, and the obtained macromonomer copolymer is added to an acrylic resin, thereby achieving both impact resistance and transparency.

[0010] Japanese Patent Publication No. 62-21804 Japanese Patent Application Laid-Open No. 2008-274290 Japanese Patent Application Laid-Open No. 2022-065185

[0011] The method described in Patent Document 3 uses a molding material that is melt-moldable and has excellent moldability to obtain a molded product with good impact resistance. However, there is a problem in that the toughness is low and the impact resistance value in a notched Charpy impact test is insufficient.

[0012] The first aspect of the present invention aims to solve the problems of the prior art and to provide a resin composition, molding material, and molded article that are acrylic resin molding materials containing block copolymers and / or graft copolymers and that have excellent toughness and impact resistance while maintaining excellent moldability.

[0013] In the method described in Patent Document 2, the synthesis of the block copolymer, the synthesis of the matrix (meth)acrylic polymer, and the production of the molded body are carried out simultaneously, which makes the method unsuitable for melt molding and makes it difficult to mold into thin films or complex shapes. In the method described in Patent Document 3, a molded body with good impact resistance is obtained using a melt-moldable molding material. However, there are problems with the resulting molded body having relatively high haze and insufficient transparency.

[0014] The second aspect of the present invention aims to solve the problems of the prior art and to provide a resin composition and molding material that can give molded articles having excellent transparency and appearance quality realized by excellent moldability, excellent impact resistance, flexibility, and low haze.

[0015] The present inventors have found that the problems of the first invention and the second invention can be solved by blending specific (meth)acrylic resins in combination.

[0016] That is, the present invention is summarized as follows.

[0017] [1] A resin composition comprising a (meth)acrylic polymer (A), a (meth)acrylic copolymer (B), and a rubbery graft polymer (C) having a crosslinked structure, wherein the (meth)acrylic polymer (A) is a random copolymer and / or a homopolymer, the (meth)acrylic polymer (A) contains 50% by mass or more of repeating units derived from methyl methacrylate, the (meth)acrylic copolymer (B) is a block copolymer and / or a graft copolymer containing a polymer (B1) and a polymer (B2), the polymer (B1) contains 50% by mass or more of repeating units derived from methyl methacrylate and has a glass transition temperature of 0°C or higher, and the polymer (B2) has a glass transition temperature of less than 0°C.

[0018] [2] The resin composition according to [1], containing 25% by mass or more of the (meth)acrylic copolymer (B) relative to 100% by mass of the total of the resin composition.

[0019] [3] The resin composition according to [1] or [2], wherein the (meth)acrylic copolymer (B) has a weight average molecular weight of 300,000 or more in terms of polymethyl methacrylate.

[0020] [4] The resin composition according to any one of [1] to [3], wherein the rubbery graft polymer (C) is a particulate rubber containing a core composed of a rubber portion and a shell component, and the rubbery portion is a silicone-acrylic composite rubber.

[0021] [5] The resin composition according to any one of [1] to [4], wherein the resin composition further comprises a (meth)acrylic polymer (D) which is a random copolymer and / or a homopolymer, wherein the (meth)acrylic polymer (A) comprises 50% by mass or more of repeating units derived from methyl methacrylate and has a mass average molecular weight of 50,000 to 200,000, wherein the (meth)acrylic polymer (D) comprises 50% by mass or more of repeating units derived from methyl methacrylate and has a mass average molecular weight of 500,000 or more, and wherein the (meth)acrylic polymer (D) is contained in an amount of 0.2 to 15% by mass relative to 100% by mass of the total of the resin composition.

[0022] [6] A resin composition comprising a (meth)acrylic polymer (A), a (meth)acrylic copolymer (B), and a (meth)acrylic polymer (D), wherein the (meth)acrylic polymer (A) and the (meth)acrylic polymer (D) are random copolymers and / or homopolymers, the (meth)acrylic polymer (A) contains 50% by mass or more of repeating units derived from methyl methacrylate and has a mass average molecular weight of 50,000 to 200,000, the (meth)acrylic copolymer (B) is a block copolymer and / or graft copolymer, and the (meth)acrylic polymer (D) contains 50% by mass or more of repeating units derived from methyl methacrylate and has a mass average molecular weight of 500,000 or more, and the (meth)acrylic polymer (D) is contained in an amount of 0.2 to 15% by mass, relative to 100% by mass of the total of the resin composition.

[0023] [7] The resin composition according to [6], wherein the (meth)acrylic polymer (A) comprises a (meth)acrylic polymer (A2) having a melt flow rate of 7.0 g / 10 min or more as measured in accordance with JIS K7210 or ISO 1133 under conditions of 230°C and 37.3 N, and the (meth)acrylic polymer (A2) is contained in an amount of 3 to 15 mass% relative to 100 mass% of the total resin composition.

[0024] [8] The resin composition according to [6] or [7], wherein the (meth)acrylic copolymer (B) contains a polymer (B1) containing 50% by mass or more of repeating units derived from methyl methacrylate.

[0025] [9] The resin composition according to any one of [6] to [8], wherein the resin composition further contains a rubbery graft polymer (C) having a crosslinked structure.

[0026]

[10] The resin composition according to any one of [1] to [9], wherein the (meth)acrylic copolymer (B) contains a structural unit derived from a macromonomer (b1) represented by the following general formula (1):

[0027]

[0028] (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. n is a natural number from 1 to 10,000.

[0029]

[11] A molding material comprising the resin composition according to any one of [1] to

[10] .

[0030]

[12] The molding material according to

[11] , which is a molding material for injection molding.

[0031]

[13] A molded article using the molding material according to

[11] or

[12] .

[0032]

[14] A vehicle part comprising the molded article according to

[13] .

[15] A vehicle exterior part comprising the molded article according to

[13] .

[16] A housing equipment member comprising the molded article according to

[13] .

[17] An optical member comprising the molded article according to

[13] .

[18] A medical member comprising the molded article according to

[13] .

[19] A container comprising the molded article according to

[13] .

[0033]

[20] The molding material according to

[11] , which is a molding material for extrusion molding.

[0034]

[21] A molded body comprising the molding material according to

[11] or

[20] .

[0035]

[22] A film comprising the molded article according to

[21] .

[23] An optical film comprising the molded article according to

[21] .

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

[21] .

[25] A film for housing equipment comprising the molded article according to

[21] .

[26] A vehicle part comprising the molded article according to

[21] .

[27] A vehicle exterior part comprising the molded article according to

[21] .

[0036] The resin composition and molding material of the first aspect of the present invention have excellent melt moldability, and molded articles obtained by molding using this molding material have excellent toughness and impact resistance.

[0037] The resin composition and molding material of the second invention of the present invention have excellent melt moldability, and molded articles obtained by molding using this molding material have excellent impact resistance, flexibility, and excellent transparency and appearance quality realized by low haze.

[0038] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the preferred embodiments. The present invention is not limited to the following description, and various modifications can be made within the scope of the present invention.

[0039] 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".

[0040] In the present invention, "monomer" means an unpolymerized compound (monomer component before polymerization). "Repeating unit" and "structural unit" mean 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 "monomer unit." A "repeating unit" or "structural unit" may be a unit formed directly by a polymerization reaction, or may be a unit in which a part of the unit is converted into a different structure by processing the polymer.

[0041] In the present invention, "% by mass" indicates the content of a specific component contained in a total amount of 100% by mass.

[0042] In the present invention, unless otherwise specified, a numerical range expressed using "to" in this specification means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits. In other words, "A to B" means A or more and B or less.

[0043] In the present invention, the mass average molecular weight (Mw) of the (meth)acrylic polymer (A), the (meth)acrylic polymer (D), and other (meth)acrylic polymers means a mass average molecular weight that is a relative molecular weight determined using gel permeation chromatography (GPC) in terms of polystyrene. The mass average molecular weight (Mw) of the (meth)acrylic copolymer (B) means a mass average molecular weight that is a relative molecular weight determined using gel permeation chromatography (GPC) in terms of polymethyl methacrylate (PMMA).

[0044] [Resin Composition] The resin composition of the first aspect of the present invention contains, as essential components, a (meth)acrylic polymer (A), a (meth)acrylic copolymer (B), and a rubbery graft polymer (C) having a crosslinked structure. The resin composition of the first aspect of the present invention may contain, as necessary, a (meth)acrylic polymer (D) and other components.

[0045] The resin composition of the second aspect of the present invention contains, as essential components, a (meth)acrylic polymer (A), a (meth)acrylic copolymer (B), and a (meth)acrylic polymer (D). The (meth)acrylic polymer (A) may optionally contain a (meth)acrylic polymer (A2). The resin composition of the second aspect of the present invention may optionally contain a rubbery graft polymer (C) having a crosslinked structure and other components.

[0046] Hereinafter, the "first invention" and the "second invention" will be collectively referred to as "the present invention."

[0047] [(Meth)acrylic polymer (A)] The (meth)acrylic polymer (A) is one of the components of the resin composition of the present invention.

[0048] The (meth)acrylic polymer (A) is a random copolymer and / or a homopolymer, and contains 50 mass% or more of repeating units derived from methyl methacrylate (hereinafter, may be referred to as "methyl methacrylate units") relative to 100 mass% of the total weight of the (meth)acrylic polymer (A).

[0049] The methyl methacrylate unit content is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, relative to 100% by mass of the total weight of the (meth)acrylic polymer (A). When the lower limit of the methyl methacrylate unit content 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 resin can be maintained in good condition. On the other hand, the upper limit of the methyl methacrylate unit content is not particularly limited, and the (meth)acrylic polymer (A) may be a homopolymer of methyl methacrylate (the methyl methacrylate unit content is 100% by mass).

[0050] The (meth)acrylic polymer (A) may contain, in addition to repeating units derived from methyl methacrylate, units derived from other comonomers copolymerizable with methyl methacrylate (hereinafter, sometimes referred to as "comonomer units") depending on the purpose. For example, when the (meth)acrylic polymer (A) contains repeating units derived from acrylate (hereinafter, sometimes referred to as "acrylate units") as comonomer units, depolymerization of the (meth)acrylic polymer (A) 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, functions such as the glass transition temperature (Tg), processability, heat resistance, refractive index, weather resistance, mold releasability, and thermal decomposition resistance of the (meth)acrylic polymer (A) can be controlled.

[0051] The upper limit of the content of the comonomer unit in the (meth)acrylic polymer (A) is preferably 20% by mass or less relative to 100% by mass of the total mass of the (meth)acrylic polymer (A), since this allows the (meth)acrylic polymer (A) to maintain favorable performance such as heat resistance, hardness, scratch resistance, weather resistance, transparency, and processability. On the other hand, the lower limit of the content of the comonomer unit is not particularly limited, and as described above, the (meth)acrylic polymer (A) may not contain the comonomer unit, i.e., may be a homopolymer of methyl methacrylate.

[0052] Examples of the comonomers that form the comonomer units of the (meth)acrylic polymer (A) include the following a) to i).

[0053] 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.

[0054] These may be used alone or in combination of two or more.

[0055] Among these, methyl acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred in terms of easy availability of the monomer, and methyl acrylate is more preferred in terms of ensuring the rigidity and heat resistance of the resin composition, molding material, and molded article of the present invention.

[0056] The (meth)acrylic polymer (A) in the first invention preferably has a polystyrene-equivalent weight average molecular weight (Mw) of 50,000 to 200,000, more preferably 70,000 to 150,000, and more preferably 80,000 to 120,000.

[0057] In the second aspect, the (meth)acrylic polymer (A) has a polystyrene-equivalent weight average molecular weight (Mw) of 50,000 to 200,000, preferably 70,000 to 150,000, and more preferably 80,000 to 120,000. When the lower limit of Mw of the (meth)acrylic polymer (A) is 50,000 or more, the (meth)acrylic resin is more likely to exhibit its properties, such as heat resistance, hardness, scratch resistance, weather resistance, and transparency. When the upper limit of Mw of the (meth)acrylic polymer (A) is 200,000 or less, the melt viscosity falls within an appropriate range, resulting in good melt-kneadability and processability.

[0058] The (meth)acrylic polymer (A) may be used alone or in combination of two or more different polymers having different resin compositions, physical properties, etc.

[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, based on 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 (meth)acrylic resins, 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, more preferably 85% by mass or less, and even more preferably 80% by mass or less, based on a total of 100% by mass of the resin composition of the present invention. When the content of the (meth)acrylic polymer (A) is 90% by mass or less, the content of the (meth)acrylic copolymer (B) or the rubbery graft polymer (C) having a crosslinked structure and / or the (meth)acrylic polymer (D) increases, thereby enabling the production of a resin composition, molding material, and molded article that are balanced in terms of moldability, toughness, impact resistance, or flexibility, moldability, transparency, etc.

[0060] [(Meth)acrylic polymer (A2)] The (meth)acrylic polymer (A2) is used as a part of the (meth)acrylic polymer (A) in the resin composition of the second invention, if necessary.

[0061] The role of the (meth)acrylic polymer (A2) is to adjust the fluidity during melt molding. By using an appropriate amount of the (meth)acrylic polymer (A2) in the resin composition, it is possible to suppress the haze of a molded article produced by injection molding, prevent molding defects, and impart good appearance quality.

[0062] From the viewpoint of effectively obtaining the above-mentioned effects, 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 or more, and even more preferably 12.0 g / 10 min or more, 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.

[0063] The polystyrene-equivalent weight average molecular weight (Mw) of the (meth)acrylic polymer (A2), like the (meth)acrylic polymer (A), is 50,000 to 200,000, preferably 70,000 to 150,000, and more preferably 80,000 to 120,000. When the lower limit of Mw of the (meth)acrylic polymer (A2) is 50,000 or more, the (meth)acrylic resin's properties such as heat resistance, hardness, scratch resistance, weather resistance, and transparency are easily exhibited. When the upper limit of Mw of the (meth)acrylic polymer (A2) is 200,000 or less, the melt viscosity falls within an appropriate range, resulting in good melt-kneadability and processability.

[0064] When the (meth)acrylic polymer (A2) contains a comonomer unit, the comonomer unit is the same as the comonomer unit contained in the (meth)acrylic polymer (A) described above.

[0065] The content of comonomer units in the (meth)acrylic polymer (A2) is preferably 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 2% by mass or more of comonomer units, the aforementioned melt flow rate is more easily achieved. When the (meth)acrylic polymer (A2) contains 20% by mass or less of comonomer units, the properties of the (meth)acrylic resin, such as heat resistance, hardness, scratch resistance, weather resistance, and transparency, are more easily exhibited.

[0066] The content of the (meth)acrylic polymer (A2) in the resin composition of the second 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, relative to 100% by mass of the resin composition. By setting the content of the (meth)acrylic polymer (A2) to 1% by mass or more, it is possible to effectively suppress haze and molding defects in the molded product. 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.

[0067] [(Meth)acrylic Copolymer (B)] The resin composition of the present invention contains a (meth)acrylic copolymer (B).

[0068] The (meth)acrylic copolymer (B) is a block copolymer and / or a graft copolymer, that is, the (meth)acrylic copolymer (B) has at least one of the structure of a block copolymer and the structure of a graft copolymer.

[0069] The block and / or graft structure of the (meth)acrylic copolymer (B) according to the present invention 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 to have at least one of the diblock, triblock, and graft structures, since this can impart excellent impact resistance and flexibility and is relatively easy to produce.

[0070] The (meth)acrylic copolymer (B) according to the first invention is a block copolymer and / or graft copolymer containing a polymer (B1) and a polymer (B2), wherein the polymer (B1) contains 50% by mass or more of repeating units derived from methyl methacrylate and has a glass transition temperature of 0° C. or higher, and the polymer (B2) has a glass transition temperature of less than 0° C. In the first invention, the (meth)acrylic copolymer (B) preferably has a weight average molecular weight of 300,000 or more in terms of polymethyl methacrylate.

[0071] The (meth)acrylic copolymer (B) according to the second aspect of the invention preferably contains a polymer (B1) containing 50% by mass or more of repeating units derived from methyl methacrylate, and similarly to the first aspect of the invention, it is particularly preferable that the (meth)acrylic copolymer (B) contains the polymer (B1) and the polymer (B2) described below.

[0072] In the (meth)acrylic copolymer (B) according to the present invention, 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) according to the present invention, the polymer (B2) has the function of imparting flexibility, impact resistance, and moldability.

[0073] The (meth)acrylic copolymer (B) according to a preferred embodiment of the present invention contains a polymer (B1) and a polymer (B2) in the same polymer molecule. 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 (meth)acrylic copolymer (B) may have a main chain made of the polymer (B2) and a side chain made of the polymer (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 content of the (meth)acrylic copolymer (B) is preferably 25% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more, based on a total of 100% by mass of the resin composition of the first invention. When the content of the (meth)acrylic copolymer (B) is 25% by mass or more, the resin composition is more likely to be imparted with the fluidity and impact resistance that are characteristic of the (meth)acrylic copolymer (B). When the content of the (meth)acrylic copolymer (B) is 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less, based on a total of 100% by mass of the resin composition of the first invention. When the content of the (meth)acrylic copolymer (B) is 70% by mass or less, the content of the (meth)acrylic polymer (A) and the rubbery graft polymer (C) having a crosslinked structure is ensured, making it easier to obtain the effects of these components, and a resin composition, molding material, and molded article having a balanced moldability, toughness, impact resistance, etc. can be obtained.

[0075] The content of the (meth)acrylic copolymer (B) is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, based on a total of 100% by mass of the resin composition of the second invention. When the content of the (meth)acrylic copolymer (B) is 10% by mass or more, the resin composition is more likely to be imparted with the fluidity and flexibility that are characteristic of the (meth)acrylic copolymer (B). When the content of the (meth)acrylic copolymer (B) is 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less, based on a total of 100% by mass of the resin composition of the second invention. When the content of the (meth)acrylic copolymer (B) is 70% by mass or less, the contents of the (meth)acrylic polymer (A) and the (meth)acrylic polymer (D) are ensured, making it easier to obtain the effects of these components, and a resin composition, molding material, and molded article having a balanced flexibility, moldability, transparency, etc. can be obtained.

[0076] The lower limit of the mass average molecular weight (Mw) of the (meth)acrylic copolymer (B) according to the present invention is preferably 50,000 or more, more preferably 100,000 or more, even more preferably 200,000 or more, and particularly preferably 300,000 or more. If the mass average molecular weight (Mw) of the (meth)acrylic copolymer (B) is 50,000 or more, the flexibility and impact resistance of the resin composition, molding material, and molded article are improved. In particular, in the first aspect, if the mass average molecular weight (Mw) of the (meth)acrylic copolymer (B) is 300,000 or more, impact resistance is more easily obtained. From this viewpoint, the mass average molecular weight (Mw) of the (meth)acrylic copolymer (B) is preferably 500,000 or more, particularly 800,000 or more. The upper limit of the mass average molecular weight (Mw) of the (meth)acrylic copolymer (B) according to the present invention is preferably 5,000,000 or less, more preferably 3,500,000 or less, and even more preferably 2,000,000 or less. When the mass average molecular weight (Mw) of the (meth)acrylic copolymer (B) is 5,000,000 or less, the transparency of the resin composition, molding material, and molded article becomes good.

[0077] 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).

[0078] [Polymer (B1)] The polymer (B1) preferably contains 50 mass% or more of methyl methacrylate units. In addition, by using a comonomer unit common to the (meth)acrylic polymer (A) in the polymer (B1), the polymer (B1) can effectively exhibit its function of imparting miscibility and compatibility with the (meth)acrylic polymer (A).

[0079] The polymer (B1) preferably contains 50% 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 the total weight of the polymer (B1). If the lower limit of the content of methyl methacrylate units in the polymer (B1) is 50% by mass or more, based on 100% by mass of the total weight of the polymer (B1), the polymer (B1) has good affinity with the (meth)acrylic polymer (A), and the miscibility and compatibility are improved. The upper limit of the content of methyl methacrylate units is not particularly limited, and the polymer (B1) may be a homopolymer having a content of 100% by mass of methyl methacrylate units.

[0080] In addition to the methyl methacrylate unit, the polymer (B1) may contain a comonomer unit derived from another comonomer copolymerizable with methyl methacrylate depending on the purpose. For example, when the polymer (B1) contains an acrylate unit as a comonomer unit, 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 unit, functions such as the glass transition temperature (Tg), processability, heat resistance, refractive index, weather resistance, mold releasability, and thermal decomposition resistance of the polymer (B1) can be controlled.

[0081] The upper limit of the content of the comonomer unit in the polymer (B1) is preferably 50% by mass or less relative to the total mass (100% by mass) of the polymer (B1), since this allows good maintenance of performance such as heat resistance, hardness, scratch resistance, weather resistance, transparency, and processability. On the other hand, the lower limit of the content of the comonomer unit may be 0% by mass.

[0082] Examples of the comonomer that forms the comonomer unit of the polymer (B1) include a) to i) that are described above as the comonomer that forms the comonomer unit of the (meth)acrylic polymer (A), and one type can be used alone, or two or more types can be used in combination.

[0083] 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.

[0084] 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.

[0085] In the first invention, the glass transition temperature (Tg) of the polymer (B1) is 0° C. or higher, preferably 20° C. or higher, more preferably 40° C. or higher, and even more preferably 60° C. or higher. When the glass transition temperature (Tg) of the polymer (B1) is 0° C. or higher, the (meth)acrylic copolymer (B) can be handled as a solid. There is no particular upper limit for the glass transition temperature of the polymer (B1), but it is preferably 120° C. or lower, particularly preferably 110° C. or lower, in view of the feasibility of using readily available raw materials.

[0086] In the second invention, the glass transition temperature (Tg) of the polymer (B1) is also preferably within the above-mentioned preferred range for the same reasons as above.

[0087] In the present invention, the Tg of polymer (B1) can be calculated using the Fox equation, using the values ​​of the homopolymers of the monomers that are the structural units of polymer (B1) as described in known documents such as the Polymer Handbook (POLYMER HANDBOOK FOURTH EDITION 2003). Alternatively, the dynamic viscoelasticity of the obtained molded article can be measured, and the value of tan δ can be used as the Tg.

[0088] The lower limit of the mass average molecular weight (Mw) of the polymer (B1) in the present invention is preferably at least 3,000, more preferably at least 10,000, even more preferably at least 15,000, and particularly preferably at least 20,000. When the Mw of the polymer (B1) is 3,000 or more, the affinity of the polymer (B1) for the (meth)acrylic polymer (A) becomes good, and miscibility and compatibility can be expected to be imparted.

[0089] The upper limit of the mass average molecular weight (Mw) of the polymer (B1) in the present invention 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.

[0090] 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).

[0091] The polymer (B1) in the present invention 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.

[0092] 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 the (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 more preferably 40% by mass or more, even more preferably 45% by mass or more, and particularly preferably 50% by mass or more. On the other hand, 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 moldability and flexibility due to polymer (B2). The upper limit of the content of polymer (B1) is more preferably 70% by mass or less, even more preferably 65% ​​by mass or less.

[0093] [Polymer (B2)] The polymer (B2) imparts functions such as flexibility, impact resistance, and improved flowability during melt molding to the (meth)acrylic copolymer (B) and the resin composition, molding material, and molded article of the present invention using the same.

[0094] The glass transition temperature (Tg) of the polymer (B2) is preferably 0° C. or lower, more preferably −10° C. or lower, even more preferably −20° C. or lower, and particularly preferably −35° C. or lower. When the glass transition temperature (Tg) of the polymer (B2) is 0° C. or lower, effects such as improved flexibility, impact resistance, and flowability during melt molding can be expected. The lower limit of the glass transition temperature (Tg) of the polymer (B2) is usually −60° C.

[0095] In the present invention, the Tg of polymer (B2) can be calculated using the Fox equation, using the values ​​of the homopolymers of the monomers that are the structural units of polymer (B2) as described in known documents such as the Polymer Handbook (POLYMER HANDBOOK FOURTH EDITION 2003). Alternatively, the dynamic viscoelasticity of the obtained molded article can be measured, and the value of tan δ can be used as the Tg.

[0096] 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 more preferably 30% by mass or more, and even more preferably 35% by mass or more. On the other hand, 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 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.

[0097] The refractive index of the polymer (B2) is preferably set so that the difference in refractive index between the polymer (B1) and the methyl methacrylate (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.

[0098] The weight average molecular weight (Mw) of the polymer (B2) in the present invention 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. When the Mw of the polymer (B2) in the present invention is 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 and molding material of the present invention is good.

[0099] In the present invention, the mass average molecular weight (Mw) of the polymer (B2) means a mass average molecular weight (Mw) that is a relative molecular weight determined using gel permeation chromatography (GPC) and converted into polymethyl methacrylate (PMMA).

[0100] [Monomer (b2)] Monomer (b2) is a monomer unit 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.

[0101] 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. On the other hand, if the acrylate content 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).

[0102] The acrylate can provide the obtained molded article with better impact resistance, so the glass transition temperature (Tg) of the acrylate homopolymer is preferably less than 0° C. In the present invention, the Tg of the acrylate homopolymer can be calculated by using the Fox formula and employing values ​​described in known documents such as the Polymer Handbook (POLYMER HANDBOOK FOURTH EDITION 2003).

[0103] 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; Examples of suitable acrylates include carboxyl 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 may be used alone or in combination of two or more.

[0104] 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 less than 0° C. Furthermore, methyl acrylate, ethyl acrylate, and n-butyl acrylate are preferred because they are easily available.

[0105] The aromatic vinyl 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).

[0106] 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 during production of the (meth)acrylic copolymer (B) is sufficiently fast.

[0107] 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.

[0108] The monomer (b2) of the present invention may contain other monomers copolymerizable with the acrylate and the aromatic vinyl, if necessary.

[0109] Other monomers include, for example, 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, 2-methacryloyloxypropyl hexahydrophthalic acid, and 2-methacryloyl methacrylate. 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 can be appropriately selected and used.

[0110] Further, examples of other monomers include carboxy 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.

[0111] The proportion of the other monomers used is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, based on 100% by mass of the total of the monomers (b2).

[0112] [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. In addition, 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.

[0113] [Method for producing (meth)acrylic copolymer (B) using macromonomer] When the (meth)acrylic copolymer (B) is produced using a macromonomer, the macromonomer may be used as a raw material for either the polymer (B1) or the polymer (B2). Specifically, the macromonomer is copolymerized with a comonomer copolymerizable with the macromonomer to obtain a macromonomer copolymer. This macromonomer copolymer is used as the (meth)acrylic copolymer (B).

[0114] Here, as an example, a method for producing a macromonomer copolymer by copolymerizing a macromonomer (b1) as a raw material for a polymer (B1) with a monomer (b2) will be described. In this case, the polymer (B2) has the monomer (b2) as a monomer unit.

[0115] [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.

[0116] 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).

[0117] The cobalt chain transfer agent used in the present invention is represented by the following general formula (2): Examples of such cobalt chain transfer agents 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.

[0118]

[0119] (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.

[0120] 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.

[0121] The amount of the cobalt chain transfer agent used is preferably 5 ppm to 350 ppm relative to 100 parts by mass of the monomer for obtaining 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.

[0122] 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.

[0123] [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.

[0124] 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).

[0125]

[0126] (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. n is a natural number from 1 to 10,000.

[0127] <R ０ ~R ｎ In the formula (1), R ０ ~R ｎThe alkyl group, cycloalkyl group, aryl group or heterocyclic group may have a substituent.

[0128] 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.

[0129] R ０ ~R ｎ Examples 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. Among these, the cyclopropyl group, the cyclobutyl group, and the adamantyl group are preferred because of their ease of availability.

[0130] 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.

[0131] R ０ ~R ｎExamples 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.

[0132] R ０ ~R ｎ Examples of the substituents that may be possessed by R include, independently, 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'' include, independently, R ０ ~R ｎ and the like (excluding heterocyclic groups).

[0133] 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 ｎExamples 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.

[0134] 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.

[0135] <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.

[0136] <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.

[0137] The lower limit of the content of methyl methacrylate units contained in the macromonomer (b1) is not particularly limited, and a content of 50% by mass or more relative to 100% by mass of the total mass of the macromonomer (b1) 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. On the other hand, the upper limit of the content of methyl methacrylate units is not particularly limited, and may be 100% by mass of methyl methacrylate units, or may be 99% by mass or less relative to 100% by mass of the total mass of the macromonomer (b1).

[0138] 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. Furthermore, suspension polymerization is more preferred because the resulting polymer particles are easy to handle.

[0139] In the suspension polymerization method, the macromonomer copolymer is obtained as spherical particles having an average particle size of about 5 μm to 1 mm. The obtained spherical particles are easy to handle and there is little concern about dust scattering when used in processing operations such as extrusion and molding, making them suitable for use as resin compositions. Spherical particles are also preferred because they improve the moldability of the resin composition obtained by the suspension polymerization method.

[0140] The reason why suspension polymerization is superior to emulsion polymerization is not clear, but it is presumed that the suspension polymerization is superior to emulsion polymerization because, in emulsion polymerization, trace amounts of abnormal polymers and residual emulsifiers are generated, which can cause foreign matter and thickening, whereas suspension polymerization does not have such problems. Details of suspension polymerization will be described later.

[0141] Alternatively, the polymerization reaction in producing the macromonomer copolymer may be carried out using a bulk polymerization method such as a mass polymerization method or a cast polymerization method, and may include a step of heating the polymerizable mixture to polymerize it.

[0142] In the case of a solution polymerization method, it is also possible to produce a 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 it is and carrying out a copolymerization reaction.

[0143] 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 molded article can be improved. While the lower limit of the sulfur-containing chain transfer agent content is not particularly limited, it is preferable that the polymerizable composition does not contain a sulfur-containing chain transfer agent.

[0144] In producing the macromonomer copolymer, polymerization can be performed 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. When the mass average molecular weight (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 improved. On the other hand, the upper limit of the mass average molecular weight (Mw) of the copolymer is preferably 3,500,000 or less, more preferably 3,000,000 or less, and even more preferably 2,000,000 or less. When the mass average molecular weight (Mw) of the macromonomer copolymer is 3,500,000 or less, the moldability of the resin composition and molding material of the present invention is improved, and the transparency of the molded article is improved. The above upper and lower limits can be combined arbitrarily. The method for controlling the mass average molecular weight (Mw) of the copolymer to be 240,000 or more is not particularly limited, and 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.

[0145] [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 the macromonomer (b1) (b1, unit: mass%) and the content of the monomer (b2) (b2, unit: mass%) contained in the polymerizable composition (X) is preferably 35:65 to 75:25, more preferably 40:60 to 70:30, still more preferably 45:55 to 70:30, particularly preferably 50:50 to 65:35, and most preferably 55:45 to 65:35 mass%, relative to 100% by mass of the total mass of the polymerizable composition (X). When the lower limit of the content of the macromonomer (b1) contained in the polymerizable composition (X) is 35% by mass or more, or the upper limit of the content of the monomer (b2) is 65% by mass or less, relative to 100% by 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 a resin composition containing the macromonomer copolymer and the obtained molded article can be well maintained.

[0146] [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.

[0147] 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).

[0148] 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).

[0149] 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.

[0150]

[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.

[0151] iii) Aqueous Solution Preparation Step: 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, the dispersibility of the droplets of the polymerizable mixture formed in the aqueous solution when the polymerizable mixture is dispersed in the aqueous solution can be controlled.

[0152] The water used in the aqueous solution is preferably deionized water, since this improves the dispersibility of the droplets of the polymerizable mixture.

[0153] 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).

[0154] 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).

[0155] I) Syrup Preparation Step: The polymerizable composition (X) is prepared by adding a solution containing a monomer (b2) to a bead-like macromonomer (b1) produced by suspension polymerization dispersed in an aqueous solution. 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 may be the same as that described in iii) above.

[0156] 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.

[0157] 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).

[0158] 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.

[0159] In the latter stage of the polymerization reaction, the suspension may be heated to increase the reaction rate of the polymerizable composition (X) and 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.

[0160] 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.

[0161] [Rubber graft polymer (C) having a crosslinked structure] The resin composition of the first invention contains a rubber graft polymer (C) having a crosslinked structure. The resin composition of the second invention may contain a rubber graft polymer (C) having a crosslinked structure.

[0162] The rubbery graft polymer (C) having a crosslinked structure is different from the (meth)acrylic copolymer (B), and is a particulate rubber (core-shell rubber) containing a core consisting of a rubber portion and a shell component having functions such as compatibility with the matrix.

[0163] The core-shell rubber of the rubbery graft polymer (C) having a crosslinked structure is used to impart flexibility and impact resistance to the resin composition, molding material, and molded article of the present invention. In particular, the use of the rubbery graft polymer (C) having a crosslinked structure is effective for achieving improved toughness, which is difficult to achieve with the (meth)acrylic copolymer (B), and for obtaining good results in notched Charpy impact tests. Furthermore, the acrylic copolymer (B) may cause anisotropy in mechanical properties due to the orientation of the rubber component in the flow direction during injection molding. In contrast, the core-shell rubber has crosslinked rubber particles, which reduces deformation of the rubber domains during injection molding. Using the acrylic copolymer (B) in combination with the rubbery graft polymer (C) having a crosslinked structure effectively eliminates anisotropy.

[0164] The rubbery graft polymer (C) having a crosslinked structure can be appropriately selected from commonly available ones and used. Examples of the core of the core-shell rubber include acrylic rubber containing acrylate as a structural unit, butadiene rubber containing butadiene as a structural unit, butadiene-acrylic composite rubber containing butadiene and acrylate as structural units, and silicone-acrylic composite rubber containing dimethylsiloxane and acrylate as structural units.

[0165] Among these, those in which the refractive index of the core is close to that of the (meth)acrylic polymer (A) are preferred, since this results in good transparency of the resin composition. From the viewpoint of refractive index, preferred core types are acrylic rubber containing acrylate as a structural unit and butadiene-acrylic composite rubber containing butadiene and acrylate as structural units. Preferred core types are acrylic rubber and silicone-acrylic composite rubber containing dimethylsiloxane and acrylate as structural units, since this results in good weather resistance of the resin composition. In terms of the effect of improving toughness and impact resistance, preferred core types are butadiene rubber containing butadiene as a structural unit, butadiene-acrylic composite rubber containing butadiene and acrylate as structural units, and silicone-acrylic composite rubber containing dimethylsiloxane and acrylate as structural units. Furthermore, silicone-acrylic composite rubber is particularly preferred, since it achieves both improved toughness and impact resistance and weather resistance. The type of core can be appropriately selected and used depending on the performance requirements of the molded article. Multiple core-shell rubbers with different core types may be used in combination.

[0166] The rubbery graft polymer (C) having a crosslinked structure is not particularly limited, but preferably has a multilayer structure of three or more layers including an inner layer, an intermediate layer, and a graft layer.

[0167] The mass average particle diameter of the rubbery graft polymer (C) having a crosslinked structure is preferably 50 nm or more, more preferably 100 nm or more, and even more preferably 200 nm or more. The mass average particle diameter of the rubbery graft polymer (C) having a crosslinked structure is preferably 1000 nm or less, more preferably 700 nm or less, even more preferably 600 nm or less, and particularly preferably 500 nm or less. If the mass average particle diameter is 50 nm or more, it functions as a rubber and can improve toughness and impact resistance. If the mass average particle diameter is 1000 nm or less, the number of particles increases, resulting in good toughness and impact resistance. The mass average particle diameter of the rubbery graft polymer (C) having a crosslinked structure is measured by the method described in the Examples section below.

[0168] The content of the rubbery graft polymer (C) having a crosslinked structure in the resin composition of the first invention, and the lower limit of the content of the rubbery graft polymer (C) having a crosslinked structure when the resin composition of the second invention contains the rubbery graft polymer (C) having a crosslinked structure, is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on 100% by mass of the total resin composition of the present invention. By including 5% by mass or more of the rubbery graft polymer (C) having a crosslinked structure, toughness, flexibility, and impact resistance can be effectively imparted to the resin composition, molding material, and molded article of the present invention. Furthermore, molded articles with little anisotropy can be obtained. The upper limit of the content of the rubbery graft polymer (C) having a crosslinked structure is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, based on 100% by mass of the total resin composition of the present invention. When the content of the rubbery graft polymer (C) having a crosslinked structure is 50% by mass or less, good moldability can be ensured for the resin composition and molding material of the present invention.

[0169] [(Meth)acrylic polymer (D)] The resin composition of the second invention contains a (meth)acrylic polymer (D) different from the (meth)acrylic polymer (A) and the (meth)acrylic copolymer (B). The resin composition of the first invention may also contain this (meth)acrylic polymer (D).

[0170] The (meth)acrylic polymer (D) has the effect of suppressing the haze of the molded article of the present invention produced by injection molding and also suppressing molding defects, thereby improving the appearance quality.

[0171] The (meth)acrylic polymer (D) is a random copolymer and / or a homopolymer, and contains 50% by mass or more of methyl methacrylate units and has a mass average molecular weight (Mw) of 500,000 or more.

[0172] The proportion of repeating units derived from methyl methacrylate relative to a total of 100% by mass of the (meth)acrylic polymer (D) is 50 to 100% by mass, more preferably 60 to 90% by mass, and even more preferably 70 to 85% by mass. When the proportion of repeating units derived from methyl methacrylate contained in the (meth)acrylic polymer (D) is 50% by mass or more, the compatibility and miscibility of the (meth)acrylic polymer resin (A) and the (meth)acrylic polymer (D) are improved. When the proportion of repeating units derived from methyl methacrylate relative to a total of 100% by mass of the (meth)acrylic polymer (D) is 100% by mass or less, the softening temperature can be adjusted and thermal decomposition resistance can be improved. In other words, copolymerizing a monomer other than methyl methacrylate with the (meth)acrylic polymer (D) can balance various performance properties.

[0173] Examples of comonomers forming comonomer units other than methyl methacrylate units contained in the (meth)acrylic polymer (D) include alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, and n-butyl acrylate. Copolymerization of these comonomers with methyl methacrylate can improve the thermal decomposition resistance of the (meth)acrylic copolymer (D) during melt molding.

[0174] In the present invention, the lower limit of the polystyrene-equivalent mass average molecular weight (Mw) of the (meth)acrylic polymer (D) is 500,000 or more, preferably 700,000 or more, and more preferably 1,000,000 or more. If the mass average molecular weight (Mw) of the (meth)acrylic polymer (D) is 500,000 or more, the transparency of the obtained molded article will be good, and the appearance quality of the molded article obtained by injection molding will be good. The upper limit of the mass average molecular weight (Mw) of the (meth)acrylic polymer (D) is preferably 10,000,000 or less, more preferably 6,000,000 or less, and even more preferably 4,000,000 or less. If the mass average molecular weight (Mw) of the (meth)acrylic polymer (D) is 10,000,000 or less, the moldability will be good.

[0175] Commercially available (meth)acrylic polymers (D) may also be used. Commercially available (meth)acrylic polymers (D) include acrylic polymer processing aids, such as Metablen (registered trademark) P type manufactured by Mitsubishi Chemical Corporation. Examples of Metablen (registered trademark) P type include P-531A, P-530A, P-551A, P-550A, P-501A, and P-570A.

[0176] The (meth)acrylic polymer (D) may be used alone or in combination of two or more different polymers having different resin compositions, physical properties, etc.

[0177] The content of the (meth)acrylic polymer (D) in the resin composition of the second invention, and the content of the (meth)acrylic polymer (D) in the resin composition of the first invention when the resin composition contains the (meth)acrylic polymer (D), is 0.2% by mass or more, preferably 0.5% by mass or more, and more preferably 1.0% by mass or more, relative to 100% by mass of the total resin composition of the present invention. When the content of the (meth)acrylic polymer (D) is 0.2% by mass or more, the haze of the molded article of the present invention produced by injection molding is kept low, and molding defects such as flow marks and jetting are suppressed, thereby improving the appearance quality. The upper limit of the content of the (meth)acrylic polymer (D) is 15% by mass or less, preferably 10% by mass or less, and more preferably 5% by mass or less, relative to 100% by mass of the total resin composition of the present invention. When the content of the (meth)acrylic polymer (D) is 15% by mass or less, the effect on the moldability of the resin composition of the present invention and the molding material is suppressed.

[0178] [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 rubbery graft polymer (C) having a crosslinked structure, and the (meth)acrylic polymer (D).

[0179] Other components are added to the resin composition as needed.

[0180] Examples of other components include release agents, antioxidants, heat stabilizers, impact modifiers, flexibility imparting agents, weather resistance modifiers, colorants, inorganic pigments, organic pigments, carbon black, ferrite, conductivity imparting agents, ultraviolet absorbers, infrared absorbers, lubricants, inorganic fillers, reinforcing agents, plasticizers, antiplasticizers, neutralizing agents, crosslinking agents, flame retardants, preservatives, insect repellents, fragrances, radical scavengers, sound absorbing materials, core-shell rubber, etc. These other components may be used alone or in combination of two or more.

[0181] [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. Furthermore, the resin composition of the present invention can be processed into pellets after heated, melt-kneaded, and then suitably used as a molding material.

[0182] [Molded Article] The resin composition and molding material of the present invention are shaped by known melt molding methods such as extrusion molding, injection molding, compression molding, and blow molding to form a molded article. The shape of the molded article of the present invention is not particularly limited, and examples thereof include a film shape, a sheet shape, a plate shape, a roughly box-like shape, and a three-dimensional shape having curved surfaces. The resin composition and molding material of the first invention are particularly excellent in moldability, toughness, and impact resistance, and therefore can be suitably used as an injection molding material and an extrusion molding material. The resin composition and molding material of the second invention are particularly excellent in moldability, flexibility, and transparency, and therefore can be suitably used as an injection molding material and an extrusion molding material.

[0183] [Uses of Molded Articles] The molded article of the first invention is excellent in toughness and impact resistance, particularly impact resistance in a notched Charpy impact test. The molded article of the second invention is excellent in flexibility, impact resistance, and transparency. Therefore, the molded article of the present invention can be suitably used for optical components such as display front panels for liquid crystal displays, organic electroluminescence displays, etc., signage, lighting equipment, toys, containers, home appliances, vehicle parts such as vehicle interior and exterior parts, medical components, housing equipment components, industrial materials, building materials, lenses, light guide plates, light collecting components, and optical components such as optical films used in displays (image display devices) for liquid crystal displays, organic electroluminescence displays, etc.

[0184] In particular, the film-shaped molded article of the second invention not only has excellent impact resistance and transparency over a wide temperature range, but also is less likely to whiten when folded. Furthermore, the film-shaped molded article of the second invention is less likely to break when repeatedly folded, making it suitable for use in foldable displays and the like.

[0185] The present invention will be described in more detail below with reference to Examples, Comparative Examples, and Reference Examples. The present invention is not limited to the following Examples. In the following, "parts" means "parts by mass."

[0186] [Evaluation Methods] Evaluations in the Examples, Comparative Examples, and Reference Examples were carried out by the following methods.

[0187] (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, Comparative Examples, and Reference 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. A gel permeation chromatography measurement device (manufactured by Tosoh Corporation, model name: HLC-8320) was used, with 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) connected in series. 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 amount: 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 Mw and Mn were determined.

[0188] (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, Comparative Examples, and Reference 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. In the GPC measurement of the copolymer, a high-performance liquid chromatography measurement apparatus (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. The measurement was performed under the following conditions. Separation column temperature: 40°C Mobile phase: tetrahydrofuran Flow rate of mobile phase: 0.6 mL / min Sample injection amount: 10 μL A calibration curve was prepared 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 mass average molecular weight (Mw) and number average molecular weight (Mn), which are relative molecular weights converted into polymethyl methacrylate, were determined.

[0189] (Mass Average Particle Diameter of Rubbery Graft Polymer (C) Having a Crosslinked Structure) The mass average particle diameter of the rubbery graft polymer (C) having a crosslinked structure was measured as follows. The obtained latex was diluted with distilled water to prepare a diluted latex with a solids concentration of about 3%, and 0.1 mL of the diluted latex was used as a sample. Measurement was performed using a CHDF2000 particle size distribution analyzer manufactured by MATEC Corporation, USA, under conditions of a flow rate of 1.4 mL / min, a pressure of about 2.76 MPa (about 4000 psi), and a temperature of 35°C. In the measurement, a capillary cartridge for particle separation and a carrier liquid were used, and the liquid was made approximately neutral. Prior to the measurement, monodisperse polystyrene with known particle diameters manufactured by DUKE Corporation, USA, was used as a standard particle diameter substance, and particle diameters were measured at a total of 12 points ranging from 20 nm to 800 nm to create a calibration curve.

[0190] (Preparation of Test Pieces) The raw materials of the resin composition were melt-kneaded using a 26 mmφ screw-type twin-screw extruder (manufactured by Shibaura Machine Co., Ltd., model name: TEM-26SX) to obtain a pellet-shaped resin composition (molding material). The obtained resin composition was injection-molded using an injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd., model name: SE100EV-A) at a cylinder temperature of 250 ° C. and a mold temperature of 60 ° C. to obtain a plate-shaped molded body (width 50 mm, length 100 mm, thickness 3 mm) and a rod-shaped molded body (width 8 mm, length 80 mm, thickness 4 mm). These molded bodies were used as test pieces for evaluation. Conditioning of the test pieces was performed in accordance with JIS K6717-2.

[0191] (Transparency Evaluation: Haze Measurement) As an index of transparency of the molded articles obtained in Examples, Comparative Examples, and Reference Examples, the haze (unit: %) was measured. The haze (unit: %) was measured at room temperature of 23°C using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., device name: NDH2000) in accordance with JIS K7316, using the plate-shaped molded articles as test pieces.

[0192] (Evaluation of Rigidity: Bending Test) As an index of rigidity of the molded articles obtained in the Examples, Comparative Examples, and Reference Examples, the flexural modulus (unit: MPa) of test pieces of the rod-shaped molded articles was measured using a Tensilon universal testing machine (manufactured by Orientec Co., Ltd., product name: RTC-1250A) in accordance with JIS K 7171. The flexural modulus was determined from a stress-strain curve obtained under conditions of room temperature of 23°C and a test speed of 2 mm / min.

[0193] (Evaluation of Impact Resistance: Charpy Impact Test) As an index of impact resistance of the molded articles obtained in Examples, Comparative Examples, and Reference Examples, the Charpy impact strength (unit: kJ / m) was measured using a Charpy impact tester (manufactured by Toyo Seiki Co., Ltd., product name: DG-CP) in accordance with JIS K7111 using the rod-shaped molded articles as test pieces (with and without notches). ２ ) was measured. The notch was a V-notch with r = 0.25 mm. Five specimens were tested using a 15 J hammer, and the average value was calculated. The test temperature was 23°C. For the notched specimens, measurements were also taken at a test temperature of -30°C.

[0194] (Evaluation of Moldability: Melt Flow Rate) As an index of melt moldability of the resin compositions obtained in the Examples, Comparative Examples, and Reference Examples, the melt flow rate (MFR) (unit: g / 10 min) was measured in accordance with JIS K7210 (Method A) using a melt indexer (manufactured by Techno Seven Co., Ltd., device name: L243) at a temperature of 230°C and a load of 37.3 N. The heating time for the resin composition was 4 minutes, and the sample cutting time interval was 10 to 120 seconds depending on the MFR value of the sample.

[0195] (Raw Materials) The abbreviations for the compounds used in the Examples, Comparative Examples and Reference 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.) AMA: allyl methacrylate (manufactured by Mitsubishi Chemical Corporation) 1,3BD: 1,3-butanediol dimethacrylate (manufactured by Mitsubishi Chemical Corporation) TBHP: t-butyl hydroperoxide CHP: cumene hydroperoxide nOM: n-octyl mercaptan SFS: sodium formaldehyde sulfoxylate dihydrate (Rongalit) 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) Emulsifier (1): polyoxyethylene alkyl ether phosphate ester salt (manufactured by Toho Chemical Co., Ltd., trade name: Phosphanol RS-610NA) ACRYPET (registered trademark) VH: trade name, manufactured by Mitsubishi Chemical Corporation, (meth)acrylic polymer containing 95% by mass or more of methyl methacrylate units, mass average molecular weight 100,000, MFR = 2.0 g / 10 min (230°C, 37.3 N) ACRYPET (registered trademark) VH5: trade name, manufactured by Mitsubishi Chemical Corporation, (meth)acrylic polymer containing 95% by mass or more of methyl methacrylate units, mass average molecular weight 80,000, MFR = 5.5 g / 10 min (230°C, 37.3 N) ACRYPET (registered trademark) MF: trade name, manufactured by Mitsubishi Chemical Corporation, a (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, 37.3 N) METABLEN (registered trademark) P-530A: trade name, manufactured by Mitsubishi Chemical Corporation, a linear (meth)acrylic polymer containing 50% by mass or more of methyl methacrylate units, mass average molecular weight of 2,000,000 or more METABLEN (registered trademark) P-551A: trade name, manufactured by Mitsubishi Chemical Corporation, a linear (meth)acrylic polymer containing 50% by mass or more of methyl methacrylate units, mass average molecular weight of 1,000,000 or more.

[0196] [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.

[0197] 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.

[0198] 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.

[0199] 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.

[0200] [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.

[0201] Next, the inside of the polymerization apparatus was thoroughly purged with nitrogen, and the aqueous dispersion was heated to 80°C and held there for 3 hours, and then heated to 90°C and held 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, and the filtrate was washed with deionized water and dried at 40°C for 16 hours to obtain a bead-like macromonomer (b1). The obtained macromonomer had a number average molecular weight (Mn) of 21,300 and a mass average molecular weight (Mw) of 39,100.

[0202] The Tg of a homopolymer of methyl methacrylate (MMA) is 105°C (POLYMER HANDBOOK FOURTH EDITION 2003), and the Tg of a homopolymer of methyl acrylate (MA) is 10°C (POLYMER HANDBOOK FOURTH EDITION 2003). The Tg of macromonomer (b1) corresponding to polymer (B1) was calculated to be 99°C using the Fox equation.

[0203] [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 4, 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 and maintained at 70 ° C for 1 hour 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 maintained for 4 hours, and then heated to 90 ° C and maintained for 1 hour. After cooling to below 40 ° C, it was filtered through a filter cloth, and the filtrate was washed with deionized water. The filtered residue was then dried at 40°C for 12 hours using a hot air circulation dryer to obtain a bead-like 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.

[0204] The Tg of a homopolymer of styrene (ST) is 100°C (POLYMER HANDBOOK FOURTH EDITION 2003), and the Tg of a homopolymer of n-butyl acrylate (BA) is -54°C (POLYMER HANDBOOK FOURTH EDITION 2003). The Tg of the polymer (B2) contained in the (meth)acrylic copolymer (B) was calculated to be -37.5°C using the Fox equation.

[0205] [Production Example 5: Synthesis of rubbery graft polymer (C-1) having a crosslinked structure] 168 parts of deionized water were placed in a five-neck flask equipped with a stirrer, a reflux condenser, a nitrogen inlet, a monomer addition port, and a thermometer. Then, the system was heated to 80°C while being purged with nitrogen under stirring and mixing, and 4.0 x 10 ferrous sulfate was added. －５ parts, disodium ethylenediaminetetraacetate 1.2 x 10 －４0.4 parts of sodium formaldehyde sulfoxylate dihydrate were placed in a flask. Five minutes later, a mixture of 22.0 parts of MMA, 16.0 parts of BA, 2.0 parts of ST, 1.2 parts of 1,3BD, 0.15 parts of AMA, 0.07 parts of TBHP, and 1.44 parts of emulsifier (1) was added over 2 hours as an inner layer composition, and the mixture was maintained at 80°C for 1 hour to complete the polymerization of the inner layer. The polymerization rate of the obtained latex (unreacted monomer was measured by gas chromatography, the same applies hereinafter) was 99% or more, and the mass average particle size of the polymer for the inner layer was 190 nm.

[0206] Subsequently, an aqueous solution of 0.2 parts of SFS dissolved in 3.0 parts of deionized water was added to the latex and kept for 15 minutes, and then a mixture of 49.0 parts of BA, 11.0 parts of ST, 0.15 parts of 1,3BD, 1.0 part of AMA, 0.17 parts of CHP, and 0.96 parts of emulsifier (1) was added dropwise over 3 hours as a composition for the intermediate layer, and kept for 2 hours to complete the polymerization of the intermediate layer. The polymerization rate of the obtained latex was 99% or more, and the mass average particle size of the polymer formed up to the intermediate layer was 260 nm.

[0207] Subsequently, an aqueous solution of 0.2 parts of SFS dissolved in 3.0 parts of deionized water was added to the latex and held for 15 minutes. Then, a mixture of 57.0 parts of MMA, 3.0 parts of MA, 0.1 part of TBHP, and 0.18 parts of nOM was added dropwise over 2 hours as a graft layer composition, and the mixture was held for 1 hour to complete the polymerization of the graft layer. The polymerization rate of the final latex obtained was 99% or more. The mass average particle size of the polymer was 280 nm.

[0208] Subsequently, 300 parts of a 1.3% aqueous calcium acetate solution was charged into a stainless steel vessel as a recovery agent aqueous solution, and the temperature was raised to 80°C with mixing and stirring, and 300 parts of the final latex was continuously added over 10 minutes. Thereafter, the temperature was raised to 92°C and maintained for 5 minutes. The mixture was cooled to room temperature, washed with deionized water, and filtered using a centrifugal dehydrator (1300G, 3 minutes) to obtain a wet resin. The resin was then dried at 75°C for 48 hours to obtain a white powdery rubbery graft polymer (C-1) having a crosslinked structure.

[0209] [Production Example 6: Synthesis of Rubber-like Graft Polymer (C-2) Having a Crosslinked Structure] 2 parts of tetraethoxysilane, 2 parts of γ-methacryloyloxypropyldimethoxymethylsilane, and 96 parts of octamethylcyclotetrasiloxane were mixed to obtain 100 parts of a siloxane mixture. 150 parts of distilled water in which 1.00 parts of sodium dodecylbenzenesulfonate had been dissolved was added to this, and the mixture was stirred at 10,000 rpm with a homomixer for 5 minutes. After that, the mixture was passed through a homogenizer twice at a pressure of 20 MPa to obtain a stable premixed organosiloxane emulsion. The emulsion was then placed in a separable flask equipped with a cooling condenser, and a mixture of 0.20 parts of sulfuric acid and 49.8 parts of distilled water was added over 3 minutes. The mixture was then heated to 80°C, maintained at this temperature for 7 hours, and then cooled. The resulting reaction mixture was then held at room temperature for 6 hours and neutralized with an aqueous caustic soda solution to obtain a polyorganosiloxane latex.

[0210] 33.56 parts of the polyorganosiloxane latex obtained above (10.0 parts in terms of polymer) was collected in a separable flask, and 200 parts of distilled water was added and mixed, and then a mixture of 58.8 parts of butyl acrylate, 1.2 parts of allyl methacrylate, and 0.3 parts of t-butyl hydroperoxide was added.

[0211] The atmosphere inside the separable flask was replaced with nitrogen by passing a nitrogen stream through it, and the temperature was raised to 50°C. When the liquid temperature reached 50°C, an aqueous solution of 0.001 parts of ferrous sulfate, 0.003 parts of ethylenediaminetetraacetic acid disodium salt, and 0.24 parts of Rongalit in 10 parts of distilled water was added to initiate radical polymerization. This state was maintained for 1 hour to complete the polymerization of the acrylate component, yielding a composite rubber latex of polyorganosiloxane rubber and butyl acrylate.

[0212] After the liquid temperature of this latex had dropped to 65°C, a mixture of 28 parts of methyl methacrylate, 2 parts of butyl acrylate, and 0.20 parts of t-butyl hydroperoxide was added dropwise over 1 hour to polymerize. After the dropwise addition was completed, the temperature was maintained at 60°C or higher for 1 hour and then cooled to obtain a latex of a rubbery graft polymer in which a methyl methacrylate-ethyl acrylate copolymer was graft polymerized onto a composite rubber made of polydimethylsiloxane and polybutyl acrylate.

[0213] Next, 500 parts of an aqueous solution containing 1% by mass of calcium acetate was heated to 60°C and stirred, and 340 parts of the composite rubber graft copolymer latex was gradually added dropwise thereto to coagulate. A powdery rubbery graft polymer was obtained. Water was added to 100 parts of the resulting rubbery graft polymer, followed by washing for 15 minutes in a flask equipped with a stirrer. After recovery, the resulting mixture was dried to obtain a rubbery graft polymer (C-2) having a crosslinked structure in which the rubber portion was a silicone-acrylic composite rubber.

[0214] [Examples of the First Invention, Comparative Examples, and Reference Examples] [Example I-1] A pellet-shaped resin composition was prepared using a twin-screw extruder (product name: TEM-26SX, 26 mmφ, L / D≈48) manufactured by Shibaura Machine Co., Ltd. 52.5 parts of ACRYPET VH as the (meth)acrylic polymer (A), 37.5 parts of the macromonomer copolymer obtained in Production Example 4 as the (meth)acrylic copolymer (B), and 10.0 parts of the rubbery graft polymer (C) having a crosslinked structure obtained in Production Example 5 were used. The pellet-shaped resin composition was obtained by melt-kneading under conditions of a cylinder temperature of 200 to 230°C and a die temperature of 230°C. Next, using an injection molding machine (product name: SE100EV-A) manufactured by Sumitomo Heavy Industries, Ltd., the obtained resin composition was used to prepare test specimens for evaluation under conditions of a cylinder temperature of 250°C and a mold temperature of 60°C. Bending tests and Charpy impact tests were performed using the obtained injection-molded specimens. The melt flow rate was measured using dried pelletized resin compositions. The resin compositions and the evaluation results of the test pieces obtained are shown in Table 1.

[0215] [Examples I-2 to I-5, Comparative Examples I-1 to I-5, Reference Example I-1] In the same manner as in Example I-1, pellet-shaped resin compositions were prepared using the resin compositions shown in Table 1, and test pieces were prepared and evaluated by injection molding. The resin compositions and the evaluation results of the obtained test pieces are shown in Table 1.

[0216]

[0217] The following can be seen from Table 1. Comparing Examples I-1 to I-5 with Comparative Examples I-1 and I-2, it can be seen that Examples I-1 to I-5 have good notched Charpy impact test values ​​due to the effect of the rubbery graft polymer (C) having a crosslinked structure, and that toughness and impact resistance are improved. Comparing Examples I-1 to I-5 with Comparative Examples I-3 and I-4, it can be seen that Examples I-1 to I-5 have high melt flow rate values ​​due to the effect of the (meth)acrylic copolymer (B), and that they have good moldability. In Example I-4, the rubber portion is a silicone-acrylic composite rubber, and due to the effect of the rubbery graft polymer (C-2) having a crosslinked structure, the notched Charpy impact test value at -30°C is good, and that toughness and impact resistance at low temperatures are improved. Comparative Example I-5 does not contain the (meth)acrylic copolymer (B), and therefore has a low melt flow rate and poor moldability. Example I-5 further contains a (meth)acrylic polymer (D), and it is clear that the haze value is lowered and the transparency and surface appearance are improved compared to Reference Example I-1. As described above, Examples I-1 to I-5 achieve both high toughness and impact resistance and good moldability.

[0218] [Examples of the Second Invention, Comparative Examples, and Reference Examples] [Example II-1] A pellet-shaped resin composition was prepared using a twin-screw extruder (product name: TEM-26SX, 26 mmφ, L / D≈48) manufactured by Shibaura Machine Co., Ltd. 42.5 parts of ACRYPET VH5 as the (meth)acrylic polymer (A), 37.5 parts of the macromonomer copolymer obtained in Production Example 4 as the (meth)acrylic copolymer (B), 20.0 parts of the rubbery graft polymer (C-1) having a crosslinked structure obtained in Production Example 5, and 3.0 parts of Metablen P-551A as the (meth)acrylic polymer (D) were melt-kneaded under conditions of a cylinder temperature of 200 to 230°C and a die temperature of 230°C to obtain a pellet-shaped resin composition. Next, using an injection molding machine (product name: SE100EV-A) manufactured by Sumitomo Heavy Industries, Ltd., test specimens for evaluation were produced using the obtained resin composition under conditions of a cylinder temperature of 250°C and a mold temperature of 60°C. Using the obtained injection-molded specimens, haze value measurement, bending test, and Charpy impact test were carried out. For melt flow rate measurement, dried pellet-shaped resin composition was used. The resin composition and the evaluation results of the obtained test specimens are shown in Table 2.

[0219] [Examples II-2 to II-6, Comparative Examples II-1 to II-3, Reference Example II-1] In the same manner as in Example II-1, pellet-shaped resin compositions were prepared using the resin compositions shown in Table 2, and test pieces were prepared and evaluated by injection molding. The resin compositions and the evaluation results of the obtained test pieces are shown in Table 2.

[0220]

[0221] The following can be seen from Table 2. Comparing Example II-6 with Comparative Example II-2, it can be seen that adding a (meth)acrylic polymer (D) to a resin composition containing a (meth)acrylic polymer (A) and a (meth)acrylic polymer (B) reduces the haze value, improving transparency and surface appearance. Compared to Comparative Example II-3, Example II-6 and Comparative Example II-2 show that the (meth)acrylic polymer (B) contributes to a low flexural modulus, flexibility, and impact resistance, and the melt flow rate is large, resulting in excellent moldability. In Examples II-1 to II-5, the inclusion of a rubbery graft polymer (C) having a crosslinked structure in addition to the (meth)acrylic copolymer (B) provides even more excellent flexibility and impact resistance. Comparing Examples II-1 to II-5 with Comparative Example II-1 shows that the (meth)acrylic copolymer (B) contributes to a low flexural modulus, flexibility, and impact resistance, and the melt flow rate is large, resulting in excellent moldability. Furthermore, comparing Example II-1 with Examples II-2 and II-3, it can be seen that P530A is more effective at suppressing haze than P551A. Compared to Example II-3, Examples II-4 and II-5, which used MF as the (meth)acrylic polymer (A2), further suppressed haze and improved moldability. Compared to Reference Example II-1, Examples II-1 to II-6 contain (meth)acrylic polymer (D), thereby suppressing haze to a low level, providing excellent transparency and good appearance quality. Reference Example II-1 does not contain (meth)acrylic polymer (D), so its transparency is insufficient, but it is excellent in impact resistance and moldability. Comparative Example II-3, which contains only (meth)acrylic polymer (A), is excellent in transparency, but has a high flexural modulus, poor flexibility, and poor impact resistance.

[0222] The resin composition of the first invention contains as its constituent components a (meth)acrylic polymer (A), a specific (meth)acrylic copolymer (B), and a rubbery graft polymer (C) having a crosslinked structure, and therefore has excellent toughness, impact resistance, and moldability. The molding material and molded article of the first invention are obtained by molding the resin composition, and therefore have excellent toughness, impact resistance, and moldability.

[0223] The resin composition of the second invention contains the (meth)acrylic polymer (A) and the specific (meth)acrylic copolymer (B) and (meth)acrylic polymer (D) as constituent components, and therefore has excellent flexibility, moldability, and transparency. The molding material and molded article of the second invention are obtained by molding the resin composition, and therefore have excellent flexibility, impact resistance, and transparency, and can provide molded articles with good appearance quality.

[0224] 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. 2023-101504 filed on June 21, 2023, and Japanese Patent Application No. 2023-101505 filed on June 21, 2023, which are incorporated by reference in their entirety.

Claims

1. A resin composition comprising a (meth)acrylic polymer (A), a (meth)acrylic copolymer (B), and a rubbery graft polymer (C) having a crosslinked structure, The (meth)acrylic polymer (A) is a random copolymer and / or a homopolymer. The (meth)acrylic polymer (A) contains 50% by mass or more of repeating units derived from methyl methacrylate, The (meth)acrylic copolymer (B) is a block copolymer and / or graft copolymer comprising polymer (B1) and polymer (B2), The polymer (B1) contains 50% by mass or more of repeating units derived from methyl methacrylate, and has a glass transition temperature of 0°C or higher. A resin composition in which the polymer (B2) is a polymer with a glass transition temperature of less than 0°C.

2. The resin composition according to claim 1, wherein the (meth)acrylic copolymer (B) is contained in an amount of 25% by mass or more based on a total mass of 100% by mass of the resin composition.

3. The resin composition according to claim 1 or 2, wherein the mass-average molecular weight of the (meth)acrylic copolymer (B) on a polymethyl methacrylate basis is 300,000 or more.

4. The resin composition according to claim 1 or 2, wherein the rubbery graft polymer (C) is a particulate rubber comprising a core made of a rubbery portion and a shell component, and the rubbery portion is a silicone-acrylic composite rubber.

5. The resin composition further comprises a (meth)acrylic polymer (D) which is a random copolymer and / or homopolymer. The (meth)acrylic polymer (A) contains 50% by mass or more of repeating units derived from methyl methacrylate, and has a mass-average molecular weight of 50,000 to 200,000. The (meth)acrylic polymer (D) contains 50% by mass or more of repeating units derived from methyl methacrylate, and has a mass-average molecular weight of 500,000 or more. The resin composition according to claim 1 or 2, wherein the (meth)acrylic polymer (D) is contained in an amount of 0.2 to 15% by mass based on 100% by mass of the total resin composition.

6. A resin composition comprising (meth)acrylic polymer (A), (meth)acrylic copolymer (B), and (meth)acrylic polymer (D), The (meth)acrylic polymer (A) and (meth)acrylic polymer (D) are random copolymers and / or homopolymers. The (meth)acrylic polymer (A) contains 50% by mass or more of repeating units derived from methyl methacrylate, and has a mass-average molecular weight of 50,000 to 200,000. The (meth)acrylic copolymer (B) is a block copolymer and / or a graft copolymer. The (meth)acrylic polymer (D) contains 50% by mass or more of repeating units derived from methyl methacrylate, and has a mass-average molecular weight of 500,000 or more. A resin composition containing the (meth)acrylic polymer (D) in an amount of 0.2 to 15% by mass relative to 100% by mass of the total resin composition.

7. The (meth)acrylic polymer (A) comprises (meth)acrylic polymer (A2) whose melt flow rate, measured at 230°C and 37.3N in accordance with JIS K7210 or ISO 1133, is 7.0 g / 10 min or more. The resin composition according to claim 6, wherein 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.

8. The resin composition according to claim 6 or 7, wherein the (meth)acrylic copolymer (B) comprises a polymer (B1) containing 50% by mass or more of repeating units derived from methyl methacrylate.

9. The resin composition according to claim 6 or 7, wherein the resin composition further comprises a rubbery graft polymer (C) having a crosslinked structure.

10. The resin composition according to claim 1, 2, 6, or 7, wherein the (meth)acrylic copolymer (B) comprises a constituent unit derived from a macromonomer (b1) represented by the following general formula (1). 【Chemistry 1】 (In formula (1), R ０ ~R ｎ Each of these is independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group. １ ~X ｎ Each of these is independently either a hydrogen atom or a methyl group. Z is a terminal group. n is a natural number between 1 and 10,000.

11. A molding material comprising the resin composition according to claim 1, 2, 6, or 7.

12. The molding material according to claim 11, which is a molding material for injection molding.

13. A molded article using the molding material described in claim 11.

14. A vehicle part comprising the molded body described in claim 13.

15. A vehicle exterior part comprising the molded body described in claim 13.

16. A housing equipment component comprising the molded body described in claim 13.

17. An optical component comprising the molded body described in claim 13.

18. A medical component comprising the molded body described in claim 13.

19. A container comprising the molded body described in claim 13.

20. The molding material according to claim 11, which is a molding material for extrusion molding.

21. A film comprising the molded article described in claim 13.

22. An optical film comprising the molded article described in claim 13.

23. An image display device comprising the molded body described in claim 13.

24. A film for residential equipment, comprising the molded article described in claim 13.

25. A vehicle part comprising the molded body described in claim 13.

26. A vehicle exterior part comprising the molded body described in claim 13.

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