Methacrylic melt-extruded molded body

Abstract

The methacrylic melt-extrusion molded article according to the present invention contains: a methacrylic resin (A) that includes 80 mass% or more of a methyl methacrylate unit and that has a weight average molecular weight of 50,000-500,000; an acrylic multilayer polymer (B) that has, in the inside thereof, at least one rubber component layer (b1) having a mean particle size in a range of 0.05-0.15 μm and that has, at the outermost part thereof, at least one thermoplastic resin component layer (b2); and an acrylic block copolymer (C) including a methacrylic acid ester polymer block (c1) and an acrylic acid ester polymer block (c2). The methacrylic melt-extrusion molded article is characterized in that 1-60 mass% of the molded article is an acetone insoluble matter, and, in a cross section parallel to the extrusion direction of the molded article, the acrylic acid ester polymer block (c2) forms spherical or columnar phases, the diameters of the spherical phases or the breadths of the columnar phases are 1-100 nm, and the lengths of the columnar phases are 10-500 nm.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims priority based on Japanese Patent Application No. 2019 - 137232 filed on July 25, 2019 and Japanese Patent Application No. 2019 - 173842 filed on September 25, 2019 (the entire disclosures of which are incorporated herein by reference). The present invention relates to a methacrylic melt - extruded molded article. More specifically, the present invention relates to a methacrylic melt - extruded molded article that is excellent in transparency, surface smoothness, resistance to flexural whitening, pencil hardness, flexibility, moldability, and appearance after molding, and is suitable for decorative applications and building material applications.

Background Art

[0002] Methacrylic resin molded articles have excellent optical properties such as transparency and weather resistance, and the molded articles have a beautiful appearance. Therefore, they have been used in decorative applications such as interior and exterior automotive parts and building materials. A methacrylic resin film that is excellent in weather resistance for the purpose of protecting a decorative layer such as a printed layer and imparting design properties such as a high - class feeling and a sense of depth, and also has good transparency, pencil hardness, and surface smoothness has been conventionally used as a surface protection film. In recent years, the application to members molded into a three - dimensional shape has also increased. Problems during three - dimensional molding include stress whitening during molding, an increase in surface haze, cracking, etc. In addition to the above - mentioned properties, a surface protection layer requires stress - whitening resistance, surface smoothness, flexibility, and flexural resistance.

[0003] As a resin molded article excellent in whitening property during molding, a method using cross - linked rubber polymer particles having a particle diameter of 0.1 μm or less (Patent Document 1) has been proposed. However, it has been difficult to suppress cracking during molding while maintaining high surface hardness only with cross - linked polymer particles or block copolymers having a small particle size.

[0004] As a film excellent in pencil hardness and stress whitening resistance, methods using rubber polymer particles with a particle diameter of 0.07 μm or less (Patent Document 1) and methods using block copolymers as rubber particles (Patent Document 2) have been disclosed. However, it has been difficult to suppress cracking during molding while maintaining high surface hardness with only small-sized polymer particles.

[0005] As a film excellent in pencil hardness, stress whitening resistance, and crack resistance, a method using two types of elastomer particles with different particle diameters, namely crosslinked elastomer particles with a large particle diameter of 0.2 to 0.4 μm and crosslinked elastomer particles with a small particle diameter of 0.18 μm or less, has been disclosed (Patent Documents 3 and 4). However, it is known that adding even a small amount of elastomer particles with a large particle diameter of 0.2 μm or more impairs surface smoothness and deteriorates the haze of the film, and the film performance has not reached excellent levels in terms of transparency, surface smoothness, pencil hardness, stress whitening resistance, and crack resistance.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide a methacrylic melt-extruded molded article suitable for decorative use, which is excellent in transparency, surface smoothness, flexural stress whitening resistance, pencil hardness, flexibility, moldability, and appearance after molding.

Means for Solving the Problems

[0008] As a result of investigations to solve the above problems, the present invention including the following aspects has been completed. 〔1〕 A methacrylic resin (A) containing 80% by mass or more of methyl methacrylate units and having a weight average molecular weight of 50,000 or more and 500,000 or less, An acrylic multilayer polymer (B) having at least one rubber component layer (b1) inside and at least one thermoplastic resin component layer (b2), with the outermost layer being the thermoplastic resin component layer (b2), and the average particle diameter of the rubber component layer (b1) being in the range of 0.05 to 0.15 μm, and an acrylic block copolymer (C) containing a methacrylic acid ester polymer block (c1) and an acrylic acid ester polymer block (c2) A methacrylic melt-extruded molded article containing wherein the acetone-insoluble content of the molded article is 1 to 60% by mass, and in a cross-section parallel to the extrusion direction of the molded article, the acrylic acid ester polymer block (c2) forms a spherical or columnar phase, the diameter of the spherical phase or the short diameter of the columnar phase is 1 nm or more and 100 nm or less, and the long diameter of the columnar phase is 10 nm or more and 500 nm or less. 〔2〕 In the acrylic multilayer polymer (B), the rubber component layer (b1) contains a copolymer composed of 50 to 98.99% by mass of acrylic acid ester monomer units, 1 to 44.99% by mass of other monofunctional monomer units, and 0.01 to 10% by mass of polyfunctional monomers, and the thermoplastic resin component layer (b2) contains a copolymer composed of 40 to 100% by mass of methacrylic acid ester monomer units and 60 to 0% by mass of other monomer units The methacrylic melt-extruded molded article according to 〔1〕, characterized in that. 〔3〕 The acrylic block copolymer (C) contains at least one methacrylic acid ester polymer block (c1) and at least one acrylic acid ester polymer block (c2), and the acrylic block copolymer (C) has 30 to 60% by mass of the methacrylic acid ester polymer block (c1) and 40 to 70% by mass of the acrylic acid ester polymer block (c2). The methacrylic melt-extruded molded article according to [1], characterized in that the content of the acrylic block copolymer (C) in the methacrylic melt-extruded molded article is 1 to 15% by mass. 〔4〕 The methacrylic melt-extruded molded article according to [1], wherein the methacrylic melt-extruded molded article is a film having a thickness of 20 to 200 μm. 〔5〕 The methacrylic melt-extruded molded article according to any one of [1] to [4], further containing a matting agent. 〔6〕 The methacrylic melt-extruded molded article according to any one of [1] to [5], further comprising a functional layer. 〔7〕 The methacrylic melt-extruded molded article according to any one of [1] to [6], wherein the methacrylic melt-extruded molded article is a film, and the film is laminated with another thermoplastic resin film. 〔8〕 The methacrylic melt-extruded molded article according to any one of [1] to [7], which is for decoration. 〔9〕 The methacrylic melt-extruded molded article according to any one of [1] to [7], which is for building materials. 〔10〕 A method for producing a methacrylic melt-extruded molded article, comprising a step of melt-extruding a methacrylic resin composition using a T-die. The methacrylic resin composition includes a methacrylic resin (A) containing 80% by mass or more of methyl methacrylate units and having a weight average molecular weight of 50,000 or more and 500,000 or less, an acrylic multilayer polymer (B) having at least one rubber component layer (b1) inside and at least one thermoplastic resin component layer (b2), and having a thermoplastic resin component layer (b2) as the outermost layer, and an acrylic block copolymer (C) containing a methacrylic ester polymer block (c1) and an acrylic ester polymer block (c2). In the melt extrusion step, a method for producing a methacrylic melt extruded molded body, characterized in that the shear rate applied at die discharge is in the range of 200 to 650 / s.

Effects of the Invention

[0009] The methacrylic melt extruded molded body of the present invention is excellent in transparency, surface smoothness, flexural whitening resistance, pencil hardness, and flexibility, and is suitable for decorative applications and building material applications.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0011] "Methacrylic melt extruded molded body" The methacrylic melt-extruded molded article of the present invention contains a methacrylic resin (A) containing 80% by mass or more of methyl methacrylate units and having a weight average molecular weight of 50,000 or more and 500,000 or less, an acrylic multilayer polymer (B) composed of a thermoplastic resin component and including an outermost layer and at least one rubber component layer covered in contact with the outermost layer, and an acrylic block copolymer (C) containing a methacrylic acid ester polymer block (c1) and an acrylic acid ester polymer block (c2). The molded article contains these components, the acetone-insoluble content of the molded article is 1 to 60% by mass, and in a cross-section parallel to the extrusion direction of the molded article, the acrylic acid ester polymer block (c2) forms a spherical or columnar phase, the diameter of the spherical phase or the short diameter of the columnar phase is 1 nm or more and 100 nm or less, and the long diameter of the columnar phase is 10 nm or more and 500 nm or less. In one preferred embodiment of the present invention, in the molded article of the present invention, the methacrylic resin (A) forms a matrix, and a rubber-like elastic body containing the acrylic multilayer polymer (B) and the acrylic block copolymer (C) is dispersed.

[0012] The acetone-insoluble content of the methacrylic melt-extruded molded article of the present invention is preferably 1 to 60% by mass, more preferably 1 to 50% by mass, still more preferably 5 to 45% by mass, particularly preferably 10 to 40% by mass, and most preferably 20 to 40% by mass. It is preferable to use the finely cut molded article for the measurement of the acetone-insoluble content. The acetone-soluble content of the methacrylic melt-extruded molded article of the present invention is preferably 99 to 40% by mass, more preferably 99 to 50% by mass, still more preferably 95 to 55% by mass, particularly preferably 90 to 60% by mass, and most preferably 80 to 60% by mass.

[0013] The acetone-insoluble content can be determined by using 25 mL of acetone per 1 g of the molded article, stirring at room temperature for 24 hours, centrifuging to separate the precipitate as the acetone-insoluble content, measuring the mass after drying, and calculating according to the following formula.

[0014] [Number] The methacrylic melt-extruded molded article contains a methacrylic resin (A), an acrylic multilayer polymer (B), and an acrylic block copolymer (C) in the following proportions: · Content of methacrylic resin (A) Preferably 10 to 89.9% by mass, more preferably 20 to 79% by mass · Content of acrylic multilayer polymer (B) Preferably 10 to 89.9% by mass, more preferably 20 to 79% by mass · Content of acrylic block copolymer (C) Preferably 0.1 to 15% by mass, more preferably 1 to 10% by mass.

[0015] (Methacrylic resin (A)) The methacrylic resin (A) used in the present invention has a proportion of structural units derived from methyl methacrylate of 80% by mass or more, preferably 90% by mass or more. Further, the proportion of structural units derived from monomers other than methyl methacrylate in the methacrylic resin (A) is 20% by mass or less, preferably 10% by mass or less.

[0016] Examples of monomers other than methyl methacrylate include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, s-butyl acrylate, t-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate; phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate, 2-ethoxyethyl acrylate, glycidyl acrylate, allyl acrylate; cyclohexyl acrylate, norbornenyl acrylate, isobornyl acrylate and other acrylic esters; ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate; phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-ethoxyethyl methacrylate, glycidyl methacrylate, allyl methacrylate; cyclohexyl methacrylate, norbornenyl methacrylate, isobornyl methacrylate and other methacrylic esters other than methyl methacrylate; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride, maleic acid, itaconic acid; olefins such as ethylene, propylene, 1-butene, isobutylene, 1-octene; conjugated dienes such as butadiene, isoprene, myrcene; aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene; acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl pyridine, vinyl ketone, vinyl chloride, vinylidene chloride, vinylidene fluoride: and the like.

[0017] The stereoregularity of the methacrylic resin (A) is not particularly limited, and for example, those having stereoregularity such as isotactic, heterotactic, syndiotactic, etc. may be used.

[0018] The weight average molecular weight of the methacrylic resin (A) (hereinafter referred to as Mw(A)) is preferably 50,000 or more and 500,000 or less, more preferably 60,000 or more and 200,000 or less. If Mw(A) is too small, the impact resistance and toughness of the resulting molded article tend to decrease. If Mw(A) is too large, the fluidity of the methacrylic resin composition to be melt-extruded tends to decrease, and the molding processability tends to decrease.

[0019] The ratio of the weight average molecular weight Mw(A) to the number average molecular weight Mn(A) of the methacrylic resin (A), Mw(A) / Mn(A) (hereinafter, the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) may be referred to as the "molecular weight distribution") is preferably 1.03 or more and 2.6 or less, more preferably 1.05 or more and 2.3 or less, particularly preferably 1.2 or more and 2.0 or less. If the molecular weight distribution is too small, the molding processability of the methacrylic resin composition tends to decrease. If the molecular weight distribution is too large, the impact resistance of the resulting molded article tends to decrease and it tends to become brittle.

[0020] Incidentally, Mw(A) and Mn(A) are values in terms of standard polystyrene measured by GPC (gel permeation chromatography).

[0021] In addition, the molecular weight and molecular weight distribution of the methacrylic resin can be controlled by adjusting the types and amounts of the polymerization initiator and chain transfer agent.

[0022] The methacrylic resin (A) is obtained by polymerizing a monomer or monomer mixture containing 80% by mass or more of methyl methacrylate.

[0023] As the methacrylic resin (A), commercially available products may be used. Examples of such commercially available methacrylic resins include "Parapet H1000B" (MFR: 22 g / 10 min (230 °C, 37.3 N)), "Parapet GF" (MFR: 15 g / 10 min (230 °C, 37.3 N)), "Parapet EH" (MFR: 1.3 g / 10 min (230 °C, 37.3 N)), "Parapet HRL" (MFR: 2.0 g / 10 min (230 °C, 37.3 N)), and "Parapet G" (MFR: 8.0 g / 10 min (230 °C, 37.3 N)) [all are trade names, manufactured by Kuraray Co., Ltd.], etc.

[0024] (Acrylic multilayer polymer (B)) The acrylic multilayer polymer (B) has at least one rubber component layer (b1) (hereinafter, may be simply abbreviated as "(b1)") inside, and at least one thermoplastic resin component layer (b2) (hereinafter, may be simply abbreviated as "(b2)"), and is particles having a core-shell structure with the outermost layer being the thermoplastic resin component layer (b2). Note that the core of the acrylic multilayer polymer (B) is regarded as a "layer". The number of layers of the acrylic multilayer polymer (B) may be two or more, and may be three, four, or more. Examples of the layer structure include a two-layer structure of (b1)-(b2) from the center; a three-layer structure of (b1)-(b1)-(b2), (b1)-(b2)-(b2), or (b2)-(b1)-(b2); a four-layer structure such as (b1)-(b2)-(b1)-(b2), etc. Among them, from the viewpoint of handleability, a two-layer structure of (b1)-(b2); a three-layer structure of (b1)-(b1)-(b2) or (b2)-(b1)-(b2) is preferable, and a three-layer structure of (b2)-(b1)-(b2) is more preferable.

[0025] The mass ratio ((b1) / (b2)) of the total amount of the rubber component layer (b1) to the total amount of the thermoplastic resin component layer (b2) is 30 / 70 to 90 / 10. If the proportion of (b1) is less than the above range, the impact strength of the molded body may be insufficient. If the proportion of (b1) exceeds the above range, it becomes difficult to form a particle structure, and the melt fluidity may decrease, making it difficult to knead with other components and to mold the resin composition. The mass ratio ((b1) / (b2)) is preferably 30 / 70 to 80 / 20, more preferably 40 / 60 to 70 / 30. When the resin composition has two or more rubber component layers (b1), the mass ratio is calculated based on the total amount thereof, and when the resin composition has two or more thermoplastic resin component layers (b2), the mass ratio is calculated based on the total amount thereof.

[0026] (b1) preferably contains a copolymer containing 50 to 98.99% by mass of acrylic acid ester monomer units, 44.99 to 1% by mass of other monofunctional monomer units, and 0.01 to 10% by mass of polyfunctional monomer units. The content of the acrylic acid ester monomer units is more preferably 55 to 89.9% by mass, the content of the monofunctional monomer units is more preferably 44.9 to 10% by mass, and the content of the polyfunctional monomer units is more preferably 0.1 to 5% by mass.

[0027] If the content of the acrylic acid ester monomer units is less than 50% by mass, the rubber elasticity of the acrylic multilayer polymer (B) may be insufficient, and the impact strength of the molded body may be insufficient. If it exceeds 98.99% by mass, it may be difficult to form a particle structure. If the content of the other monofunctional monomer units is less than 1% by mass, the optical performance of the multilayer structure polymer particles may be insufficient. If it exceeds 44.99% by mass, the weather resistance of the acrylic multilayer polymer (B) may be insufficient. If the content of the polyfunctional monomer units exceeds 10% by mass, the rubber elasticity of the acrylic multilayer polymer (B) may be insufficient, and the impact strength of the molded body may be insufficient. If it is less than 0.01% by mass, it may be difficult to form a particle structure.

[0028] Hereinafter, the raw material monomers of the rubber component layer (b1) will be described.

[0029] Examples of acrylic esters include esters of acrylic acid and saturated aliphatic alcohols (preferably C1-C 18 saturated aliphatic alcohols), such as methyl acrylate (MA), ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate (BA), isobutyl acrylate, s-butyl acrylate, t-butyl acrylate, pentyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, and octadecyl acrylate; esters of acrylic acid and C5 or C6 alicyclic alcohols, such as cyclohexyl acrylate; esters of acrylic acid and phenols, such as phenyl acrylate; esters of acrylic acid and aromatic alcohols, such as benzyl acrylate, etc. The acrylic ester can be used alone or in combination of two or more.

[0030] Examples of other monofunctional monomers include esters of methacrylic acid and saturated aliphatic alcohols (preferably C1-C 22esters with saturated aliphatic alcohols; esters of methacrylic acid with C5 or C6 alicyclic alcohols such as cyclohexyl methacrylate; esters of methacrylic acid with phenols such as phenyl methacrylate, esters of methacrylic acid with aromatic alcohols such as benzyl methacrylate, etc., methacrylic acid esters; aromatic vinyl monomers such as styrene (St), α-methylstyrene, 1-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, and halogenated styrene; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, etc. Among them, styrene is preferred. Other monofunctional monomers can be used alone or in combination of two or more.

[0031] The polyfunctional monomer is a monomer having two or more carbon-carbon double bonds in the molecule. Examples of the polyfunctional monomer include esters of unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and cinnamic acid with unsaturated alcohols such as allyl alcohol and methallyl alcohol; diesters of the above unsaturated monocarboxylic acids with glycols such as ethylene glycol, butanediol, and hexanediol; diesters of dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and maleic acid with the above unsaturated alcohols, etc. Specifically, allyl acrylate, methallyl acrylate, allyl methacrylate, methallyl methacrylate, allyl cinnamate, methallyl cinnamate, diallyl maleate, diallyl phthalate, diallyl terephthalate, diallyl isophthalate, divinylbenzene, ethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, and hexanediol di(meth)acrylate, etc. Among them, allyl methacrylate (ALMA) is preferred. The polyfunctional monomer can be used alone or in combination of two or more.

[0032] The layer (b2) preferably contains a copolymer composed of 40 to 100% by mass of a methacrylic acid ester monomer unit and 60 to 0% by mass of other monomer units. The content of the methacrylic acid ester monomer unit is more preferably 50 to 99% by mass, still more preferably 60 to 99% by mass, particularly preferably 80 to 99% by mass, and the content of the other monomer units is more preferably 50 to 1% by mass, still more preferably 40 to 1% by mass, still more preferably 20 to 1% by mass. If the content of the methacrylic acid ester monomer unit is less than 50% by mass, the weather resistance of the acrylic multilayer polymer (B) may be insufficient.

[0033] Hereinafter, the raw material monomers of the thermoplastic resin component layer (b2) will be described.

[0034] Examples of the methacrylic acid ester include methyl methacrylate (MMA), ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, myristyl methacrylate, palmityl methacrylate, stearyl methacrylate, behenyl methacrylate, octadecyl methacrylate, phenyl methacrylate, and benzyl methacrylate. Among them, methyl methacrylate (MMA) is preferred.

[0035] Examples of the other monomers include acrylic acid and saturated aliphatic alcohols (preferably C1 to C 18esters with saturated aliphatic alcohols; esters of acrylic acid with C5 or C6 alicyclic alcohols such as cyclohexyl acrylate; aromatic vinyl monomers such as styrene (St), α-methylstyrene, 1-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, and halogenated styrenes; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; maleimide monomers such as maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-(p-bromophenyl)maleimide, and N-(chlorophenyl)maleimide; polyfunctional monomers exemplified in layer (b1), etc. Among them, alkyl acrylates such as methyl acrylate (MA), ethyl acrylate, and n-butyl acrylate (BA) are preferred.

[0036] In the acrylic multilayer polymer (B), the weight average molecular weight (Mw) measured by the GPC method of the constituent copolymer of the outermost layer (b2) is preferably in the range of 20,000 to 100,000, more preferably in the range of 30,000 to 90,000, and particularly preferably in the range of 40,000 to 80,000. If Mw is less than 20,000, the rubber elasticity of the acrylic multilayer polymer (B) may be insufficient, making it difficult to mold the resin composition. If Mw exceeds 100,000, the impact strength of the molded article may decrease.

[0037] The average particle diameter (de) of the rubber component layer (b1) of the acrylic-based multilayer polymer (B) closest to the outermost layer (preferably in contact with the outermost layer) is in the range of 0.05 to 0.15 μm. If the average particle diameter (de) is less than 0.05 μm, stress concentration in the acrylic-based multilayer polymer (B) becomes insufficient, and the impact strength of the molded article may decrease. If the average particle diameter (de) exceeds 0.15 μm, voids are generated inside the acrylic-based multilayer polymer (B), resulting in whitening. Also, when the rubber content in the resin composition is constant, as the particle diameter increases beyond a certain level, the number of particles decreases, so the surface-to-surface distance between particles tends to increase, and the probability of crack generation in the continuous phase increases, and the impact strength of the molded article may decrease. The voids mentioned here refer to fractures occurring only inside the particles, and since the amount of energy absorption is very small, it does not contribute much to the expression of impact resistance.

[0038] From the perspective of stress concentration on the acrylic-based multilayer polymer (B), the average particle diameter (de) is preferably 0.05 to 0.15 μm, more preferably 0.07 to 0.12 μm.

[0039] The average particle diameter (de) of the rubber component layer (b1) of the acrylic-based multilayer polymer (B) can be determined by a method of measuring a cross-section of the molded article with an electron microscope or a method of measuring latex by light scattering. The method using an electron microscope is the average value of the major axis diameter and the minor axis diameter of the rubber component layer ( b1 ) of the stained acrylic-based multilayer polymer (B) observed with a transmission electron microscope when a cross-section of the molded article is electron-stained with ruthenium tetroxide and constitutes the outermost layer. The method using light scattering can be measured by sampling latex polymerized up to the rubber component layer during the polymerization of the multilayer structure polymer particles and using a laser diffraction / scattering particle size distribution measuring device LA-950V2 manufactured by Horiba, Ltd.

[0040] In one preferred embodiment of the present invention, the method for producing the acrylic multilayer polymer (B) is not particularly limited as long as it can obtain the acrylic multilayer polymer (B) having the rubber component layer (b1) / thermoplastic resin component layer (b2) as described above. A preferred method for producing the acrylic multilayer polymer (B) having a three-layer structure (core - intermediate layer - outermost layer) is to emulsion polymerize the monomers for obtaining the polymer constituting the center core to obtain seed particles (i), and in the presence of the seed particles (i), emulsion polymerize the monomers for obtaining the polymer constituting the intermediate layer to obtain seed particles (ii), and in the presence of the seed particles (ii), emulsion polymerize the monomers for obtaining the polymer constituting the outermost layer to obtain seed particles (iii). The acrylic multilayer polymer (B) having a two-layer structure or a four-layer or more layer structure can be easily produced by those skilled in the art with reference to the above description of the production method of the acrylic multilayer polymer (B) having a three-layer structure. The emulsion polymerization method or the seed emulsion polymerization method is a technique well known in the art as a technique for obtaining general multilayer structure polymer particles, so a detailed description can refer to other documents. In the case of the above preferred example, the seed particles (i) are single-layer particles composed of the thermoplastic resin component layer (b2, core), the seed particles (ii) are two-layer particles composed of the thermoplastic resin component layer (b2, core)+rubber component layer (b1, intermediate layer), and the seed particles (iii) are three-layer particles composed of the thermoplastic resin component layer (b2, core)+rubber component layer (b1, intermediate layer)+thermoplastic resin component layer (b2, outermost layer).

[0041] In the polymerization reaction step, the polymerization conditions are adjusted so that the Mw of the constituent copolymer of at least the thermoplastic resin component layer (b2) constituting the outermost part is 20,000 to 100,000. The adjustment of the polymerization conditions is mainly adjusted by the amount of a molecular weight regulator such as an alkyl mercaptan. The polymerization conditions of the entire polymerization reaction step are adjusted so that the average particle diameter up to the outermost thermoplastic resin component layer (b2) in the finally obtained acrylic multilayer polymer (B) is in the range of 0.05 to 0.15 μm. In addition, the average particle diameter up to the outermost thermoplastic resin component layer (b2) in the acrylic-based multilayer polymer particles (B) can be measured by the light scattering method using a laser diffraction / scattering particle size distribution measuring apparatus LA-950V2 manufactured by Horiba, Ltd. by sampling the polymerized latex during the polymerization of the multilayer structure polymer particles.

[0042] (Acrylic block copolymer (C)) The acrylic block copolymer (C) used in the present invention has a methacrylic acid ester polymer block (c1) and an acrylic acid ester polymer block (c2). The acrylic block copolymer (C) may have only one methacrylic acid ester polymer block (c1) or may have a plurality of them. Also, the acrylic block copolymer (C) may have only one acrylic acid ester polymer block (c2) or may have a plurality of them. Such an acrylic block copolymer (C) has good compatibility with the methacrylic resin (A) and the acrylic-based multilayer polymer (B).

[0043] From the above viewpoint of compatibility, as the acrylic block copolymer (C), a block copolymer containing 10 to 80% by mass of a polymer block (c1) having a methacrylic acid ester monomer unit and 90 to 20% by mass of a polymer block (c2) mainly having an acrylic acid ester monomer unit (however, the total amount of the polymer block (c1) and the polymer block (c2) is 100% by mass) is preferable. In the acrylic block copolymer (C), the content of the polymer block (c1) is more preferably 20 to 70% by mass, still more preferably 30 to 60% by mass, and the content of the polymer block (c2) is more preferably 80 to 30% by mass, still more preferably 70 to 40% by mass.

[0044] The number of polymer blocks (c1) in one molecule may be singular or plural. When the number of polymer blocks (c1) in one molecule is plural, the composition and molecular weight of the structural units of the plural polymer blocks (c1) may be the same or different. Similarly, the number of polymer blocks (c2) in one molecule may be singular or plural. When the number of polymer blocks (c2) in one molecule is plural, the composition and molecular weight of the structural units of the plural polymer blocks (c2) may be the same or different.

[0045] The polymer block (c1) mainly contains methacrylic acid ester monomer units. The content of the methacrylic acid ester monomer units in the polymer block (c1) is preferably 80% by mass or more, more preferably 90% by mass or more, particularly preferably 95% by mass or more, and most preferably 98% by mass or more, and it may be composed only of methacrylic acid ester monomer units.

[0046] Hereinafter, the raw material monomers of the methacrylic polymer block (c1) will be described.

[0047] Examples of the methacrylic ester include methyl methacrylate (MMA), ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate, isobornyl methacrylate, phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, glycidyl methacrylate, and allyl methacrylate (ALMA). Among them, from the viewpoints of improving transparency and heat resistance, methyl methacrylate (MMA), ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, and isobornyl methacrylate are preferable, and methyl methacrylate (MMA) is particularly preferable. The methacrylic ester can be used alone or in combination of two or more.

[0048] The weight average molecular weight (Mw(c1)) of the methacrylic polymer block (c1) preferably has a lower limit of 5,000, more preferably 8,000, still more preferably 12,000, particularly preferably 15,000, and most preferably 20,000, and an upper limit preferably of 150,000, more preferably 120,000, and particularly preferably 100,000. When the acrylic block copolymer (C) has a plurality of polymer blocks (c1), the weight average molecular weight (Mw(c1)) is the total amount of Mw of the plurality of polymer blocks (c1).

[0049] In one preferred embodiment of the present invention, the weight average molecular weight Mw(c1) of the methacrylic polymer block (c1) of the acrylic block copolymer (C) and the weight average molecular weight Mw(A) of the methacrylic resin (A) satisfy the following formula (Y). 0.5 ≦ Mw(A) / Mw(c1) ≦ 2.5 (Y)

[0050] The ratio of the weight average molecular weight Mw(A) of the methacrylic resin (A) to Mw(c1), i.e., Mw(A) / Mw(c1), is 0.5 or more and 2.5 or less, preferably 0.6 or more and 2.3 or less, more preferably 0.7 or more and 2.2 or less. When Mw(A) / Mw(c1) is outside the above range, the dispersed particle diameter of the acrylic block copolymer (C) in the methacrylic resin (A) becomes large, and whitening occurs when stress is applied. When Mw(A) / Mw(c1) is within the above range, the dispersed particle diameter of the acrylic block copolymer (C) in the methacrylic resin (A) becomes small, so the stress whitening resistance is excellent.

[0051] From the viewpoints of the transparency, flexibility, flexibility, flex resistance, impact resistance, moldability, and surface smoothness of the molded article of the present invention, the content of the methacrylic polymer block (c1) in the acrylic block copolymer (C) is preferably 10 to 80% by mass, more preferably 20 to 70% by mass. When the acrylic block copolymer (C) has a plurality of polymer blocks (c1), the content of the polymer block (c1) is the total content of the plurality of polymer blocks (c1).

[0052] In one preferred embodiment of the present invention, the acrylic polymer block (c2) mainly contains acrylate monomer units. The content of the acrylate monomer units in the acrylic polymer block (c2) is preferably 45% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more, and particularly preferably 90% by mass or more.

[0053] Hereinafter, the raw material monomers of the acrylic polymer block (c2) will be described.

[0054] Examples of the acrylate ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate (BA), isobutyl acrylate, s-butyl acrylate, t-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate, isobornyl acrylate, phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate, 2-methoxyethyl acrylate, glycidyl acrylate, and allyl acrylate. The acrylate ester can be used alone or in combination of two or more.

[0055] In another preferred embodiment of the present invention, from the viewpoint of transparency, as the acrylic polymer block (c2), a polymer block (c2-p) containing an alkyl acrylate monomer unit and a (meth)acrylic acid aromatic hydrocarbon ester monomer unit is preferred. Here, the content of the alkyl acrylate monomer unit in the polymer block (c2) is preferably 50 to 90% by mass, more preferably 60 to 80% by mass, and the content of the (meth)acrylic acid aromatic hydrocarbon ester monomer unit is preferably 50 to 10% by mass, more preferably 40 to 20% by mass.

[0056] In one preferred embodiment of the present invention, the weight average molecular weight Mw(c2) of the acrylic polymer block (c2) satisfies the following formula (Z), more preferably the following formula (Z1). 5,000 ≦ Mw(c2) ≦ 120,000 (Z) 40,000 ≦ Mw(c2) ≦ 120,000 (Z1)

[0057] The weight average molecular weight Mw(c2) of the acrylic polymer block (c2) preferably has a lower limit of 5,000, more preferably 15,000, still more preferably 20,000, particularly preferably 30,000, and most preferably 40,000, and an upper limit preferably of 120,000, more preferably 110,000, and particularly preferably 100,000. If Mw(c2) is too small, the impact resistance of the molded body may decrease. On the other hand, if Mw(c2) is too large, the surface smoothness of the molded body may decrease. When the acrylic block copolymer (C) has a plurality of polymer blocks (c2), the weight average molecular weight Mw(c2) is the total amount of Mw of the plurality of polymer blocks (c2).

[0058] From the viewpoints of the transparency, flexibility, flexibility, flex resistance, impact resistance, moldability, and surface smoothness of the molded body, the content of the acrylic polymer block (c2) in the acrylic block copolymer (C) is preferably 10 to 90% by mass, more preferably 20 to 80% by mass. When the acrylic block copolymer (C) has a plurality of polymer blocks (c2), the content of the polymer block (c2) is the total content of the plurality of acrylic polymer blocks (c2).

[0059] In the melt-extruded molded body, the dispersed phase of the acrylic polymer block ( c2 ) in the cross-section parallel to the extrusion direction in the methacrylic resin (A) is preferably a spherical or columnar phase. When the dispersed phase becomes a lamellar phase, the extruded molded body becomes cloudy and whitens when stressed.

[0060] Also, the particle diameter of the dispersed phase of the acrylic polymer block ( c2 ) is preferably 1 nm or more and 200 nm or less in diameter in the case of a spherical phase, and more preferably 10 nm or more and 100 nm or less. If it is less than 1 nm, the stress concentration around the acrylic polymer block is small and the flex resistance is not exhibited. If it exceeds 200 nm, it whitens when stressed.

[0061] In the case of the columnar phase, the minor axis of the columnar phase is preferably 1 nm or more and 200 nm or less, and the major axis of the columnar phase is preferably 1 nm or more and 500 nm or less, more preferably 10 nm or more and 400 nm or less. When the major axis is less than 10 nm, the stress concentration around the acrylic polymer block is small and the flex resistance is not exhibited. When it exceeds 500 nm, it turns white when stressed.

[0062] The bonding form between the methacrylic polymer block (c1) and the acrylic polymer block (c2) in the acrylic block copolymer (C) is not particularly limited. Examples of the acrylic block copolymer (C) include diblock copolymers having a (c1)-(c2) structure in which one end of the polymer block (c2) is connected to one end of the polymer block (c1); triblock copolymers having a (c2)-(c1)-(c2) structure in which one end of the polymer block (c2) is connected to each of both ends of the polymer block (c1); and linear block copolymers such as triblock copolymers having a (c1)-(c2)-(c1) structure in which one end of the polymer block (c1) is connected to each of both ends of the polymer block (c2).

[0063] Among them, diblock copolymers and triblock copolymers are preferred, and diblock copolymers having a (c1)-(c2) structure and triblock copolymers having a (c1)-(c2)-(c1) structure are more preferred.

[0064] The acrylic block copolymer (C) may have functional groups such as hydroxyl groups, carboxyl groups, acid anhydride groups, and amino groups in the molecular chain and / or at the molecular chain ends, if necessary.

[0065] The acrylic block copolymer (C) has a weight average molecular weight (Mw(C)) of 32,000 to 300,000, preferably 40,000 to 250,000, more preferably 45,000 to 230,000, and particularly preferably 50,000 to 200,000. When Mw(C) is within the above range, the amount of unmelted matter during the melt-kneading of the raw materials in the production of the resin composition, which causes the generation of lumps in the molded article, can be made extremely small.

[0066] The acrylic block copolymer (C) preferably has a ratio (Mw(C) / Mn(C)) of weight-average molecular weight (Mw(C)) to number-average molecular weight (Mn(C)) of 1.0 to 2.0, more preferably 1.0 to 1.6. When Mw(C) / Mn(C) is within the above range, the amount of unmelted matter during melt-kneading of raw materials in the production of the resin composition, which causes the generation of lumps in the molded article, can be made extremely small.

[0067] The method for producing the acrylic block copolymer (C) is not particularly limited, and a method of living polymerization of each polymer block is common. Examples of the living polymerization method include an anionic polymerization method using an organic alkali metal compound as a polymerization initiator in the presence of a mineral acid salt such as an alkali metal or alkaline earth metal salt, an anionic polymerization method using an organic alkali metal compound as a polymerization initiator in the presence of an organic aluminum compound, a polymerization method using an organic rare earth metal complex as a polymerization initiator, and a radical polymerization method using an α-halogenated ester compound as a polymerization initiator in the presence of a copper compound. A polymerization method using a polyvalent radical polymerization initiator or a polyvalent radical chain transfer agent is also included. Among them, since the acrylic block copolymer (C) can be obtained with high purity, the composition and molecular weight of each block can be easily controlled, and it is economical, the method of anionic polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organic aluminum compound is particularly preferred.

[0068] The refractive index of the acrylic block copolymer (C) is not particularly limited, preferably 1.485 to 1.495, more preferably 1.487 to 1.493. When the refractive index is within the above range, the transparency is high. In this specification, the "refractive index" means a value measured at a wavelength of 587.6 nm (D line).

[0069] (Methacrylic resin composition) By adding and kneading the acrylic-based multilayer polymer (B) according to the present invention to the mixing step of the methacrylic resin (A) and the acrylic block copolymer (C), a methacrylic resin composition for producing a methacrylic melt-extruded molded article excellent in transparency, surface smoothness, bending whitening resistance, pencil hardness, and flexibility can be obtained.

[0070] There are the following four methods for mixing the methacrylic resin (A), the acrylic-based multilayer polymer (B), and the acrylic block copolymer (C), and any of them may be selected. (i) A two-step mixing method in which the methacrylic resin (A) and the acrylic-based multilayer polymer (B) are first mixed, and the acrylic block copolymer (C) is mixed with the mixture of (A)+( B ); (ii) A two-step mixing method in which the methacrylic resin (A) and the acrylic block copolymer (C) are first mixed, and the acrylic-based multilayer polymer (B) is mixed with the mixture of (A)+( C ); (iii) A two-step mixing method in which the acrylic-based multilayer polymer (B) and the acrylic block copolymer (C) are first mixed, and the methacrylic resin (A) is mixed with the mixture of ( B )+( C ); (iv) A method of mixing the methacrylic resin (A), the acrylic-based multilayer polymer (B), and the acrylic block copolymer (C) in one step.

[0071] As the kneading method, it can be carried out by a known method such as kneading using a batch kneader such as a Banbury mixer, a pressure kneader, a Brabender plastograph, or a continuous kneader such as a single-screw, twin-screw, or multi-screw extruder. Also, a method of melting and kneading a diluted product after once producing a high-concentration master pellet by the above method may be used. From the viewpoint of productivity, it is preferably a single-screw method or a twin-screw method. In particular, a single-screw extruder is preferable because the shear energy applied to the resin composition is small.

[0072] (Rubber content) In the present invention, the total amount of the rubber component layer (b1) of the acrylic-based multilayer polymer (B) and the acrylic-based polymer block (c2) of the acrylic-based block copolymer (C) is 5 to 60% by mass, preferably 6 to 50% by mass, and more preferably 7 to 30% by mass. When the total amount of the rubber component layer (b1) and the acrylic-based polymer block (c2) is less than 5% by mass, the impact strength deteriorates, and when it exceeds 60% by mass, the rigidity deteriorates.

[0073] (c2 rubber ratio) In the present invention, the content ratio of the acrylic-based polymer block (c2) to the total rubber content of (b1) and (c2) is in the range of 5 to 90% by mass, preferably in the range of 10 to 85% by mass, and more preferably in the range of 15 to 80% by mass. When the content ratio of the acrylic-based polymer block (c2) to the rubber content is in the range of 5 to 90% by mass, the synergistic effect between the multilayer structure polymer particles and the block copolymer works, and the impact strength is excellent.

[0074] (Optional component) Within the scope that does not impair the effects of the present invention, other polymers may be contained as necessary in addition to the methacrylic resin (A), acrylic multilayer polymer (B), and acrylic block copolymer (C). Examples of other polymers include olefin resins such as polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, and polynorbornene; ethylene-based ionomers; styrene-based resins such as polystyrene, styrene-maleic anhydride copolymer, high-impact polystyrene, AS resin, ABS resin, AES resin, AAS resin, ACS resin, and MBS resin; methyl methacrylate-styrene copolymer; ester-based resins such as polyethylene terephthalate and polybutylene terephthalate; amide-based resins such as nylon 6, nylon 66, and polyamide elastomer; other thermoplastic resins such as polyphenylene sulfide, polyether ether ketone, polysulfone, polyphenylene oxide, polyimide, polyetherimide, polycarbonate, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacetal, and phenoxy-based resin; thermosetting resins such as phenolic resin, melamine-based resin, silicone-based resin, and epoxy-based resin; polyurethane; modified polyphenylene ether; silicone-modified resin; acrylic rubber, silicone rubber; styrene-based thermoplastic elastomers such as SEPS, SEBS, and SIS; olefin-based rubbers such as IR, EPR, and EPDM. One or more of the other polymers can be used.

[0075] The methacrylic melt-extruded molded article of the present invention may contain various additives as necessary. Examples of the additives include antioxidants, heat deterioration inhibitors, ultraviolet absorbers, light stabilizers, lubricants, mold release agents, polymer processing aids, antistatic agents, flame retardants, dyes / pigments, matting agents, anti-blocking agents, impact resistance modifiers, and phosphors. The content of these additives can be appropriately set within a range that does not impair the effects of the present invention. For example, with respect to 100 parts by mass of the thermoplastic resin composition to be subjected to melt extrusion molding, the content of the antioxidant is 0.01 to 1 part by mass, the content of the ultraviolet absorber is 0.01 to 3 parts by mass, the content of the light stabilizer is 0.01 to 3 parts by mass, the content of the lubricant is 0.01 to 3 parts by mass, the content of the dye / pigment is 0.01 to 3 parts by mass, the content of the matting agent is 0.1 to 20 parts by mass, and the content of the anti-blocking agent is preferably 0.001 to 1 part by mass. Other additives can also be added in the range of 0.01 to 3 parts by mass.

[0076] The antioxidant is effective in preventing oxidative degradation of the resin by itself in the presence of oxygen. Examples thereof include phosphorus-based antioxidants, phenol-based antioxidants, sulfur-based antioxidants, and amine-based antioxidants. Among them, from the viewpoint of preventing deterioration of optical properties due to coloring, phosphorus-based antioxidants and phenol-based antioxidants are preferable, and the use of a phenol-based antioxidant alone or the combined use of a phosphorus-based antioxidant and a phenol-based antioxidant is more preferable. When a phosphorus-based antioxidant and a phenol-based antioxidant are used in combination, it is preferable to use them in a mass ratio of phosphorus-based antioxidant / phenol-based antioxidant of 0.2 / 1 to 2 / 1, and more preferably 0.5 / 1 to 1 / 1.

[0077] Preferable examples of the phosphorus-based antioxidant include 2,2-methylenebis(4,6-di-t-butylphenyl) octyl phosphite ("Adekastab HP-10" manufactured by ADEKA Corporation), tris(2,4-di-t-butylphenyl) phosphite ("Irgafos 168" manufactured by BASF Japan Ltd.), and 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane ("Adekastab PEP-36" manufactured by ADEKA Corporation).

[0078] As phenolic antioxidants, pentaerythrityl - tetrakis[3-(3,5 - di - t - butyl - 4 - hydroxyphenyl)propionate] (「IRGANOX1010」manufactured by BASF Japan Ltd.), octadecyl - 3-(3,5 - di - t - butyl - 4 - hydroxyphenyl)propionate (「IRGANOX1076」manufactured by BASF Japan Ltd.), etc. are preferable.

[0079] As sulfur - based antioxidants, dilauryl 3,3’ - thiodipropionate, distearyl 3,3’ - thiodipropionate, pentaerythritol tetrakis(3 - laurylthiopropionate), etc. are preferable.

[0080] As amine - based antioxidants, octylated diphenylamine, etc. are preferable.

[0081] As heat - deterioration inhibitors, those that can prevent the thermal deterioration of resins by scavenging polymer radicals generated when exposed to high temperatures under substantially oxygen - free conditions are suitable. As heat - deterioration inhibitors, 2 - t - butyl - 6-(3’ - t - butyl - 5’ - methyl - hydroxybenzyl)-4 - methylphenyl acrylate (「Sumilizer GM」manufactured by Sumitomo Chemical Co., Ltd.), 2,4 - di - t - amyl - 6-(3’,5’ - di - t - amyl - 2’ - hydroxy - α - methylbenzyl)phenyl acrylate (「Sumilizer GS」manufactured by Sumitomo Chemical Co., Ltd.), etc. are preferable.

[0082] An ultraviolet absorber is a compound that has ultraviolet - absorbing ability and is said to mainly have a function of converting light energy into thermal energy. Examples of ultraviolet absorbers include benzophenones, benzotriazoles, triazines, benzoates, salicylates, cyanoacrylates, oxalic acid anilides, malonic acid esters, and formamidines, etc. Among them, benzotriazoles and triazines are preferable. One or more ultraviolet absorbers can be used.

[0083] Benzotriazoles are highly effective in suppressing the degradation of optical properties such as coloration caused by ultraviolet irradiation, and are thus suitable for optical applications. Preferred benzotriazoles include 4-methyl-2-(2H-benzotriazol-2-yl)phenol (“trade name JF-77” manufactured by Johoku Chemical Industry Co., Ltd.), 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (“trade name Tinuvin 329” manufactured by BASF Japan Ltd.), 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (“trade name Tinuvin 234” manufactured by BASF Japan Ltd.), and 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-t-octylphenol] (“Adekastab LA-31” manufactured by ADEKA Corporation), etc.

[0084] When it is desired to efficiently absorb wavelengths near 380 nm, triazine-based ultraviolet absorbers are preferably used. Such ultraviolet absorbers include 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-1,3,5-triazine (“Adekastab LA-F70” manufactured by ADEKA Corporation), and hydroxy-phenyltriazine-based ultraviolet absorbers which are analogs thereof, such as “Tinuvin 477” and “Tinuvin 460” manufactured by BASF Japan Ltd.

[0085] A light stabilizer is a compound that is said to mainly have a function of capturing radicals generated by oxidation by light. Preferred light stabilizers include hindered amines such as compounds having a 2,2,6,6-tetraalkylpiperidine skeleton. For example, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (“Adekastab LA-77Y” manufactured by ADEKA Corporation), etc.

[0086] A lubricant is a compound that is said to have the effect of improving mold release properties, workability, etc. by adjusting the slipperiness between a resin and a metal surface and preventing adhesion or sticking. For example, higher alcohols, hydrocarbons, fatty acids, fatty acid metal salts, aliphatic amides, and fatty acid esters can be mentioned. Among them, from the viewpoint of compatibility with the methacrylic resin composition, aliphatic monohydric alcohols and aliphatic amides having 12 to 18 carbon atoms are preferred, and aliphatic amides are more preferred. Aliphatic amides are classified into saturated aliphatic amides and unsaturated aliphatic amides, and unsaturated aliphatic amides are more preferred because a slip effect due to anti-adhesion is expected. Examples of unsaturated aliphatic amides include N,N'-ethylenebisoleic acid amide ("Slipax O" manufactured by Nippon Kasei Co., Ltd.) and N,N'-dioleyl adipic acid amide ("Slipax ZOA" manufactured by Nippon Kasei Co., Ltd.).

[0087] Examples of mold release agents include higher alcohols such as cetyl alcohol and stearyl alcohol; glycerin higher fatty acid esters such as monoglyceride stearate and diglyceride stearate. In the present invention, it is preferable to use higher alcohols and glycerin fatty acid monoesters in combination as mold release agents. When higher alcohols and glycerin fatty acid monoesters are used in combination, the ratio is not particularly limited, but the usage amount of higher alcohols: the usage amount of glycerin fatty acid monoesters is preferably 2.5:1 to 3.5:1, and more preferably 2.8:1 to 3.2:1, by mass ratio.

[0088] A polymer processing aid is a compound that exerts an effect on thickness accuracy and thinning when molding a methacrylic resin composition. The polymer processing aid is usually polymer particles having a particle diameter of 0.05 to 0.5 μm, which can be produced by an emulsion polymerization method.

[0089] Examples of the antistatic agent include alkyl sulfonates such as sodium heptyl sulfonate, sodium octyl sulfonate, sodium nonyl sulfonate, sodium decyl sulfonate, sodium dodecyl sulfonate, sodium cetyl sulfonate, sodium octadecyl sulfonate, sodium diheptyl sulfonate, potassium heptyl sulfonate, potassium octyl sulfonate, potassium nonyl sulfonate, potassium decyl sulfonate, potassium dodecyl sulfonate, potassium cetyl sulfonate, potassium octadecyl sulfonate, potassium diheptyl sulfonate, lithium heptyl sulfonate, lithium octyl sulfonate, lithium nonyl sulfonate, lithium decyl sulfonate, lithium dodecyl sulfonate, lithium cetyl sulfonate, lithium octadecyl sulfonate, and lithium diheptyl sulfonate.

[0090] Examples of the flame retardant include metal hydrates having a hydroxyl group or water of crystallization such as magnesium hydroxide, aluminum hydroxide, aluminum silicate hydrate, magnesium silicate hydrate, and hydrotalcite; phosphate compounds such as polyamine phosphate and phosphate ester; and silicon compounds. Phosphate ester flame retardants such as trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, tricyclohexyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, dimethylethyl phosphate, methyldibutyl phosphate, ethyldipropyl phosphate, and hydroxyphenyldiphenyl phosphate are preferred.

[0091] Examples of the dye and pigment include red organic pigments such as para red, fire red, pyrazolone red, thioindigo red, and perylene red; blue organic pigments such as cyanine blue and indanthrene blue; and green organic pigments such as cyanine green and naphthol green. One or more of these can be used.

[0092] Examples of the matting agent include glass fine particles, polysiloxane-based crosslinked fine particles, crosslinked polymer fine particles, mica, talc, calcium carbonate, barium sulfate, and the like.

[0093] Examples of the anti-blocking agent include fatty acids such as stearic acid and palmitic acid; metal salts of fatty acids such as calcium stearate, zinc stearate, magnesium stearate, potassium palmitate, and sodium palmitate; waxes such as polyethylene wax, polypropylene wax, and montanic acid-based waxes; low molecular weight polyolefins such as low molecular weight polyethylene and low molecular weight polypropylene; acrylic resin powder; polyorganosiloxanes such as dimethylpolysiloxane; amide-based resin powders such as octadecylamine, alkyl phosphates, fatty acid esters, and ethylene bisstearylamide; fluororesin powders such as tetrafluoroethylene resin; molybdenum disulfide powder; silicone resin powder; silicone rubber powder; silica, and the like.

[0094] Examples of the impact resistance modifier include core-shell type modifiers containing a diene-based rubber as a core layer component; modifiers containing a plurality of rubber particles, and the like.

[0095] Examples of the phosphor include fluorescent pigments, fluorescent dyes, fluorescent whitening dyes, fluorescent brighteners, fluorescent bleaching agents, and the like.

[0096] When adding other polymers and / or additives to the methacrylic resin composition, they may be added during the polymerization of the methacrylic resin (A) and / or the acrylic multilayer polymer (B) and / or the acrylic block copolymer (C), or may be added during the mixing with the methacrylic resin (A) and / or the acrylic multilayer polymer (B) and / or the acrylic block copolymer (C), or may be added after mixing the methacrylic resin (A) and / or the acrylic multilayer polymer (B) and / or the acrylic block copolymer (C).

[0097] The molded article of the present invention is molded by a melt extrusion method for controlling the dispersed phase of the acrylic block polymer (C). The molded article is also useful as a film, and can be well processed, for example, by an inflation method, a T-die extrusion method, which are ordinary melt extrusion methods, a calendar method, or a solution casting method. Further, if necessary, by simultaneously bringing both sides of the film into contact with a roll or a metal belt, particularly by simultaneously bringing it into contact with a roll or a metal belt heated to a temperature equal to or higher than the glass transition temperature, it is also possible to obtain a film with more excellent surface properties. Further, depending on the purpose, it is also possible to laminate-mold the film or modify the film by biaxial stretching. Among these, the T-die extrusion method is particularly preferable. The thickness of the film is preferably 20 to 200 μm, more preferably 30 to 100 μm.

[0098] In order to disperse the acrylic block polymer in a columnar phase, in the T-die extrusion method, the ratio Dr / Dt of the die lip opening (Dr) to the thickness (Dt) of the molded article is preferably in the range of 1 ≤ Dr / Dt ≤ 20, more preferably in the range of 3 ≤ Dr / Dt ≤ 10. If Dr / Dt is less than 1, the acrylic block polymer becomes a spherical phase with a large dispersed particle diameter and whitens when stress is applied. On the other hand, if Dr / Dt exceeds 20, it becomes a columnar phase with a large major axis, whitens when stress is applied, and the anisotropy increases.

[0099] When manufactured using a T-die, the shear rate applied at the time of die discharge is preferably in the range of 200 to 650 / s, more preferably in the range of 300 to 550 / s. If the shear rate is less than 200 / s, the shear applied to the block copolymer is small, the dispersed particle diameter becomes large, and it whitens. On the other hand, if the shear rate exceeds 650 / s, the block copolymer is strongly sheared, the dispersed particle diameter becomes 1 nm or less, and the flexibility of the molded article is not exhibited.

[0100] The methacrylic melt-extruded molded article of the present invention, particularly a film, can be laminated and used on metals, plastics, etc. As the lamination method, there are wet lamination in which an adhesive is applied to a metal plate such as a steel plate, then the film is placed on the metal plate and dried and bonded, dry lamination, extrusion lamination, hot melt lamination, and the like.

[0101] As a method of laminating a film on a plastic part, there are film insert molding in which the film is placed in a mold and resin is filled by injection molding, laminate injection press molding, and film in-mold molding in which the film is preformed and then placed in a mold and resin is filled by injection molding.

[0102] The methacrylic melt-extruded film of the present invention can be further laminated with a functional layer or a thermoplastic resin film to form a laminated film.

[0103] When the molded article of the present invention is a methacrylic melt-extruded film, it can be laminated with a methacrylic melt-extruded film and a functional layer to form a laminated film. The functional layer can be formed on one side or both sides of the film. Examples of the functional layer include a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, etc., and at least one of these can be included.

[0104] When the methacrylic melt-extruded film which is the molded article of the present invention is a laminated film in which a functional layer and a film are laminated, the thickness of the functional layer is preferably 0.1 to 20 μm, more preferably 1 to 10 μm, and the thickness of the laminated film is preferably 20 to 220 μm, more preferably 30 to 110 μm.

[0105] When the molded article of the present invention is a methacrylic melt-extruded film, a laminated film can be formed by laminating the methacrylic melt-extruded film and a thermoplastic resin film. The thermoplastic resin film can be formed on one or both sides of the methacrylic melt-extruded film. Examples of the thermoplastic resin of the thermoplastic resin film include various thermoplastic resins such as polyolefins (polyethylene, polypropylene, polymethylpentene, etc.), polystyrene, polycarbonate, polyvinyl chloride, methacrylic resin, nylon, polyethylene terephthalate, and copolymers having a plurality of monomer units constituting these thermoplastic resins. In the thermoplastic resin film, the thermoplastic resin may contain only one kind or two or more kinds.

[0106] In the case of the laminated film including the methacrylic melt-extruded film and the thermoplastic resin film of the present invention, the thickness of the thermoplastic resin film is preferably 20 to 200 μm, more preferably 30 to 100 μm, and the thickness of the methacrylic melt-extruded film is preferably 5 to 100 μm, more preferably 10 to 15 μm.

[0107] The methacrylic melt-extruded molded article of the present invention can be used as members for various applications. Specific applications include, for example, sign components such as advertising towers, stand signs, sleeve signs, lattice signs, rooftop signs, etc. and marking films; display components such as showcases, partition boards, store displays, etc.; lighting components such as fluorescent lamp covers, mood lighting covers, lamp shades, light ceilings, light walls, chandeliers, etc.; interior components such as furniture, pendants, mirrors, etc.; architectural components such as doors, domes, safety window glasses, partitions, staircase waistboards, balcony waistboards, roofs of leisure buildings, etc.; transportation-related components such as aircraft windshields, pilot visors, motorcycles, motorboat windshields, bus sunshades, automotive side visors, rear visors, head wings, headlight covers, sunroofs, glazing, automotive interior members, bumpers, etc.; electronic device components such as audio-visual nameplates, stereo covers, TV protection masks, vending machines, mobile phones, personal computers, etc.; medical device components such as incubators, X-ray components, etc.; equipment-related components such as machine covers, instrument covers, experimental devices, rulers, dials, observation windows, etc.; optical-related components such as liquid crystal protection plates, light guide plates, light guide films, Fresnel lenses, lenticular lenses, front panels of various displays, diffusion plates, etc.; traffic-related components such as road signs, guide plates, curve mirrors, sound insulation walls, etc.; and others, such as greenhouse materials, large aquariums, box aquariums, bathroom members, watch panels, bathtubs, sanitary ware, desk mats, gaming components, toys, masks for facial protection during welding, backsheets of solar cells, front sheets for flexible solar cells; surface materials used for personal computers, mobile phones, furniture, vending machines, bathroom members, etc.

[0108] On the other hand, the methacrylic melt-extruded molded article of the present invention, particularly the laminate of films, can be used for automotive interior and exterior materials, daily sundries, wallpapers, paint replacement applications, housings of furniture and electrical equipment, housings of OA equipment such as facsimiles, floor materials, components of electrical or electronic devices, bathroom facilities, etc.

[0109] As described above, the methacrylic melt-extruded molded article of the present invention contains a methacrylic resin (A), an acrylic multilayer polymer (B), and an acrylic block copolymer (C). By controlling the acrylic block polymer to a specific dispersed phase, it is possible to provide a methacrylic molded article and a film excellent in transparency, surface smoothness, flexural whitening resistance, pencil hardness, and flexibility, and suitable for decorative applications and building material applications.

Examples

[0110] Next, the effects of the present invention will be described with reference to Examples and Comparative Examples. It should be noted that the present invention is not limited in any way by the following Examples. In the following description, unless otherwise specified, "parts" represents "parts by mass" and "%" represents "% by mass".

[0111] The evaluation of the methacrylic melt-extruded molded article which is a film was carried out by the following method.

[0112] [Observation of morphology] Using the films (thickness 75 μm) formed from the Examples and Comparative Examples described below, cross-sectional slices of the plane parallel to the extrusion direction were prepared at a thickness of 50 nm using an ultramicrotome (Leica EM UC7rt manufactured by JEOL Ltd.). The prepared slices were stained with a 10% aqueous solution of phosphotungstic acid, and the shape of the stained part (the average particle diameter (de) of the rubber component layer (b1) in the acrylic multilayer polymer (B) and the morphology of the acrylic polymer block (c2) in the acrylic block copolymer (C)) was observed using STEM (main body: JSM-7600F, detector: SM-74240RTED manufactured by JEOL Ltd.).

[0113] (Dispersed in spherical phase) When the acrylic block copolymer is spherically (sphere) dispersed, two types of spherical stained parts with different particle diameters of the block copolymer and the acrylic multilayer polymer stained respectively are observed. For each of the two types of spherical stained parts, the average particle diameter of 30 stained parts was measured, and the component with the smaller average particle diameter was taken as the diameter of the block copolymer (Figure 1).

[0114] (Dispersed in columnar phase) When the acrylic block copolymer is dispersed in a columnar (cylinder) form, the stained portions dispersed in a columnar shape are regarded as the block copolymer, and the major axis and minor axis of 30 such stained portions were measured, and the average values were taken as the major axis and minor axis (Figure 2).

[0115] (Acetone-insoluble content) 2 g (mass before separation) of the formed film (thickness 75 μm) was put into 50 mL of acetone and stirred at room temperature for 24 hours. The entire amount of the obtained solution was centrifuged using a centrifuge (manufactured by Hitachi Koki Co., Ltd., CR20GIII) under the conditions of a rotation speed of 20,000 rpm, a temperature of 0 °C, and 180 minutes. The supernatant and the precipitate were separated and collected, and each was dried under vacuum at 50 °C for 8 hours to obtain the acetone-soluble content and the acetone-insoluble content. The mass of the obtained precipitate was measured, and the ratio of the acetone-insoluble content was determined based on the following formula. Acetone-insoluble content (%) = [(precipitate mass) / (mass before separation)] × 100

[0116] (Haze) The resin film (thickness 75 μm) was cut into 50 mm × 50 mm to obtain a test piece, and the haze was measured at 23 °C in accordance with JIS K7105 and evaluated according to the following criteria. 〇: 0.5% or less △: 0.5% to 1.0% ×: 1.0% or more [Δ Haze before and after heating] The resin film (thickness 75 μm) was cut into 100 mm × 100 mm to obtain a test piece and heated in an oven set at 100 °C for 30 minutes. The haze of the sample immediately after heating was measured, and the difference from the haze value before heating was calculated as Δ haze and evaluated according to the following criteria. 〇: 0.5% or less △: More than 0.5% and less than 1.0% ×: 1.0% or more

[0117] [Pencil hardness of the film] A resin film (75 μm) was cut into 10 cm × 10 cm to obtain test pieces, and the pencil hardness was measured in accordance with JIS K5600-5-4 and evaluated according to the following criteria. 〇: 2B or higher ×: 3B or lower

[0118] (Stress whitening resistance) A film with a thickness of 75 μm was bent at 90° at room temperature (23°C), and the presence or absence of whitening at the bent portion was confirmed. 〇: No whitening ×: Whitening present

[0119] (MIT flexibility) Test pieces were taken from the center of a film with a thickness of 75 μm, and the number of bends in a direction perpendicular to the flow direction of the film was measured by a method compliant with ISO 5626 (JIS P8115 (2001)) and evaluated according to the following criteria. ◎: 60 times or more 〇: 30 times or more ×: Less than 30 times

[0120] [Formability (250% stretchability)] A resin molded body (a film with a thickness of 75 μm) was cut into 20 cm × 30 cm, and corona discharge treatment was applied to one side thereof. Then, aluminum was deposited by vacuum evaporation to obtain a laminated film. The thickness of the aluminum layer was 30 nm. This laminated film was cut into 100 mm × 100 mm to obtain test pieces, which were set in a biaxial stretching birefringence measuring device (manufactured by Etto Co., Ltd., SDR-563K) and stretched under the conditions of a temperature of 145°C, a stretching speed of 3600% / min, and a stretching ratio of 250%. Five test pieces were stretched by such a method and evaluated as follows. 〇: None of them broke. △: One or two of them broke. ×: Three or more of them broke.

[0121] [Appearance after molding (vapor deposition property)] The laminated film obtained above was placed on white paper (manufactured by FUJI Xerox Co., Ltd., C2r), and the specular glossiness of the non-vapor-deposited surface was visually evaluated under a fluorescent lamp (200 lux). 〇: With mirror gloss (no whitening) △: Slightly with mirror gloss (no whitening) ×: Without mirror gloss (with whitening)

[0122] 〔Average particle diameter of rubber component layer (b1)〕 Using films (thickness 75 μm) formed from the following Examples and Comparative Examples, cross-sectional slices of the surface parallel to the extrusion direction were prepared at a thickness of 50 nm using an ultramicrotome (Leica EM UC7rt manufactured by JEOL Ltd.). The prepared slices were electron-stained with a 10% aqueous solution of phosphotungstic acid, and the shape (morphology) of the stained portion was observed using an electron microscope (main body: JSM-7600F, detector: SM-74240RTED manufactured by JEOL Ltd.). Regarding the observed spherical stained portions, the average particle diameter of 30 stained portions was measured for each, and this was taken as the average particle diameter of the rubber component layer (b1).

[0123] (Production Example 1) Acrylic-based multilayer polymer (B-1) Into a reactor equipped with a stirrer, thermometer, nitrogen gas inlet tube, monomer inlet tube, and reflux condenser, 150 parts by mass of deionized water, 0.10 part by mass of sodium polyoxyethylene tridecyl ether acetate, and 0.05 part by mass of sodium carbonate were charged. After thoroughly replacing the inside of the container with nitrogen gas to a state where there was substantially no oxygen, the internal temperature was set to 80°C. 0.01 part by mass of potassium persulfate was added thereto and stirred for 5 minutes. Then, 10 parts by mass of a mixture consisting of methyl methacrylate, methyl acrylate, and allyl methacrylate in a mass ratio of 93.9 / 6.1 / 0.2 was continuously added dropwise over 50 minutes. After completion of the dropwise addition, the reaction was carried out for about 30 minutes until the polymerization rate reached 98% or more.

[0124] Next, 0.05 part by mass of potassium persulfate was added to the same reactor and stirred for 5 minutes. Then, 50 parts by mass of a mixture consisting of n-butyl acrylate, styrene, and allyl methacrylate in a mass ratio of 82.2 / 17.8 / 4.0 was continuously added dropwise over 90 minutes. After completion of the dropwise addition, the reaction was carried out for about 60 minutes until the polymerization rate reached 98% or more.

[0125] Next, 0.04 part by mass of potassium persulfate was charged into the reactor and stirred for 5 minutes. Then, 40 parts by mass of a mixture consisting of methyl methacrylate, methyl acrylate, and n-octyl mercaptan in a mass ratio of 94.0 / 6.0 / 0.3 was continuously added dropwise over 30 minutes. After the addition was completed, the reaction was carried out for about 60 minutes until the polymerization rate reached 98% or more. A latex containing multilayer particles (B-1) with a volume average particle diameter of 110 nm was obtained. The average particle diameter of the rubber component layer (b-1) was 80 nm.

[0126] (Production Example 2) Acrylic Multilayer Polymer (B-2) Into a reactor equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, a monomer inlet tube, and a reflux condenser, 150 parts by mass of deionized water, 0.03 part by mass of sodium polyoxyethylene tridecyl ether acetate, and 0.05 part by mass of sodium carbonate were charged. After thoroughly replacing the inside of the container with nitrogen gas to make it substantially oxygen-free, the internal temperature was set to 80°C. Then, 0.01 part by mass of potassium persulfate was added and stirred for 5 minutes. Thereafter, 10 parts by mass of a mixture consisting of methyl methacrylate, methyl acrylate, and allyl methacrylate in a mass ratio of 93.9 / 6.1 / 0.2 was continuously added dropwise over 50 minutes. After the addition was completed, the reaction was carried out for about 30 minutes until the polymerization rate reached 98% or more.

[0127] Next, 0.05 part by mass of potassium persulfate was charged into the same reactor and stirred for 5 minutes. Then, 50 parts by mass of a mixture consisting of n-butyl acrylate, styrene, and allyl methacrylate in a mass ratio of 82.2 / 17.8 / 4.0 was continuously added dropwise over 90 minutes. After the addition was completed, the reaction was carried out for about 60 minutes until the polymerization rate reached 98% or more.

[0128] Next, 0.04 part by mass of potassium persulfate was charged into the reactor and stirred for 5 minutes. Then, 40 parts by mass of a mixture consisting of methyl methacrylate, methyl acrylate, and n-octyl mercaptan with a mass ratio of 94.0 / 6.0 / 0.3 was continuously dropped in over 30 minutes. After the dropping was completed, the reaction was carried out for about 60 minutes until the polymerization rate reached 98% or more. A latex containing multilayer structured polymer particles (B-2) with a volume average particle diameter of 220 nm was obtained. The average particle diameter of the rubber component layer (b-1) was 200 nm.

[0129] (Production Example 3) Methacrylic resin (A-1) Methacrylic resin (A-1): A methacrylic copolymer composed of methyl methacrylate (MMA) units (content 99.3% by mass) and methyl acrylate (MA) units (content 0.7% by mass), with Mw = 84,000 and Mw / Mn = 2.1, was produced according to a conventional method.

[0130] (Production Example 4) Methacrylic resin (A-2) Methacrylic resin (A-2): A methacrylic copolymer composed of methyl methacrylate (MMA) units (content 93.6% by mass) and methyl acrylate (MA) units (6.4% by mass), with Mw = 120,000 and Mw / Mn = 2.1, was produced according to a conventional method.

[0131] (Production Example 5) Block copolymer (C-1) Block copolymer (C-1): A diblock copolymer consisting of [methyl methacrylate (MMA) polymer block (c1)] - [n-butyl acrylate (BA) / benzyl acrylate (BzA) copolymer block (c2)], with a weight average molecular weight (Mw) of 120,000, a mass ratio of polymer blocks (c1):(c2) of 50:50, and a mass ratio of each monomer (MMA:BA) = (50:50), was produced according to a conventional method.

[0132] (Production Example 6) Block copolymer (C-2) Block copolymer (C-2): Consisting of [methyl methacrylate (MMA) polymer block (c1)] - [n-butyl acrylate (BA) polymer block (c2)] - [methyl methacrylate (MMA) polymer block (c1)], with a weight-average molecular weight (Mw) of 70,000, a mass ratio of polymer blocks (b1):(b2):(b1) of 14.3:50.0:35.7, and a mass ratio of each monomer (MMA:BA) = (50:50) triblock copolymer.

[0133] (Production Example 7) Block copolymer (C-3) Block copolymer (C-3): Consisting of [methyl methacrylate (MMA) polymer block (c1)] - [n-butyl acrylate (BA) polymer block (c2)] - [methyl methacrylate (MMA) polymer block (c1)], with a weight-average molecular weight (Mw) of 65,000, a mass ratio of polymer blocks (c1):(c2):(c1) of 15:70:15, and a mass ratio of each monomer (MMA:BA) = (30:70) triblock copolymer.

[0134] (Production Example 8) Block copolymer (C-4) Block copolymer (C-4): Consisting of [methyl methacrylate (MMA) polymer block (c1)] - [n-butyl acrylate (BA) polymer block (c2)] - [methyl methacrylate (MMA) polymer block (c1)], with a weight-average molecular weight (Mw) of 120,000, a mass ratio of polymer blocks (c1):(c2):(c1) of 8.5:83:8.5, and a mass ratio of each monomer (MMA:BA) = (17:83) triblock copolymer.

[0135] (Example 1) 47 parts of pellets of acrylic multilayer polymer (B-1), 50 parts of methacrylic resin (A-1) (100% MMA-derived structural unit, weight-average molecular weight 80,000), and 3 parts of pellets of acrylic block copolymer (C-1) were kneaded using a twin-screw extruder and pelletized using a pelletizer to obtain a thermoplastic resin (R1).

[0136] Using a single-screw vent extruder with a screw diameter of 50 mm and a T-die with a width of 500 mm and a lip opening of 0.5 mm, a thermoplastic resin (R1) was melt-extruded at a discharge rate of 40 kg / h and a resin temperature of 260°C to obtain a film-like melt. The shear rate was 480 / s. Next, the melt was sandwiched and pressed at a linear pressure of 30 kg / cm with a first nip roll having a gap of 50 μm, which consisted of a mirror-finished metal elastic roll adjusted to 85°C and a mirror-finished metal rigid roll adjusted to 90°C. Then, it was sandwiched and pressed at a linear pressure of 30 kg / cm with a second nip roll having a gap of 50 μm, which consisted of a mirror-finished metal rigid roll adjusted to 90°C and a mirror-finished metal rigid roll adjusted to 85°C, to obtain a single-layer resin film (1) with a thickness of 75 μm (acetone-insoluble content: 28%).

[0137] Regarding the obtained resin film (1), when the morphology of the block copolymer was confirmed by the above-described measurement method, it was found to be spherically dispersed with a diameter of 20 nm. Various evaluations were performed on this film. The evaluation results are shown in Table 1. The resin film (1) was excellent in transparency, surface hardness, stress whitening resistance, and flexibility.

[0138] (Example 2) A resin film (2) (acetone-insoluble content: 28%) was obtained in the same manner as in Example 1, except that C-2 was used as the acrylic block copolymer. Regarding the obtained resin film (2), when the morphology of the block copolymer was confirmed by the above-described measurement method, it was found to be columnarly dispersed with a minor axis of 20 nm and a major axis of 100 nm. The evaluation results are shown in Table 1. The resin film (2) was excellent in transparency, surface hardness, stress whitening resistance, and flexibility.

[0139] (Example 3) A resin film (3) (acetone-insoluble content: 29%) was obtained in the same manner as in Example 1, except that 49 parts of the acrylic-based multilayer polymer (B-1) was changed to 1 part of C-3 as the acrylic-based block copolymer. When the morphology of the block copolymer was confirmed for the obtained resin film (3) by the above-described measurement method, it was columnarly dispersed with a minor axis of 20 nm and a major axis of 100 nm. The evaluation results are shown in Table 1. The resin film (3) was excellent in transparency, surface hardness, stress whitening resistance, and flexibility.

[0140] (Example 4) A resin film (4) (acetone-insoluble content: 39%) was obtained in the same manner as in Example 1, except that 65 parts of the acrylic-based multilayer polymer (B-1) was changed to 30 parts of the methacrylic-based resin (A-1) and 5 parts of the acrylic-based block copolymer (C-2). When the morphology of the block copolymer was confirmed for the obtained resin film (4) by the above-described measurement method, it was columnarly dispersed with a minor axis of 20 nm and a major axis of 200 nm. The evaluation results are shown in Table 1. The resin film (4) was excellent in transparency, surface hardness, stress whitening resistance, and particularly flexibility.

[0141] (Example 5) A resin film (5) (acetone-insoluble content: 36%) was obtained in the same manner as in Example 1, except that 60 parts of the acrylic-based multilayer polymer (B-1) was changed to 30 parts of the methacrylic-based resin (A-1) and 10 parts of the acrylic-based block copolymer (C-1). When the morphology of the block copolymer was confirmed for the obtained resin film (5) by the above-described measurement method, it was columnarly dispersed with a minor axis of 20 nm and a major axis of 300 nm. The evaluation results are shown in Table 1. The resin film (5) was excellent in transparency, surface hardness, stress whitening resistance, and particularly flexibility.

[0142] (Example 6) A resin film (6) (acetone-insoluble content: 28%) was obtained in the same manner as in Example 1, except that 50 parts of the methacrylic resin (A-2) was changed to 50 parts and 3 parts of the acrylic block copolymer (C-2) was changed to 3 parts. When the morphology of the block copolymer in the obtained resin film (6) was confirmed by the above-described measurement method, it was columnarly dispersed with a minor axis of 20 nm and a major axis of 200 nm. The evaluation results are shown in Table 1. The resin film (6) was excellent in transparency, surface hardness, stress whitening resistance, and particularly flexibility.

[0143] (Example 7) A resin film (7) (acetone-insoluble content: 27%) was obtained in the same manner as in Example 1, except that 40 parts of the acrylic multilayer polymer (B-1) was changed to 40 parts, 5 parts of the acrylic multilayer polymer (B-2) was changed to 5 parts, and 5 parts of the acrylic block copolymer (C-2) was changed to 5 parts. When the morphology of the block copolymer in the obtained resin film (7) was confirmed by the above-described measurement method, it was columnarly dispersed with a minor axis of 20 nm and a major axis of 200 nm. The evaluation results are shown in Table 1. Although the transparency of the resin film (7) was slightly inferior, it was excellent in pencil hardness, stress whitening resistance, and particularly flexibility.

[0144] (Comparative Example 1) A resin film (8) (acetone-insoluble content: 28%) was obtained in the same manner as in Example 1, except that 50 parts of the methacrylic resin (A-2) was changed to 50 parts and 5 parts of the acrylic block copolymer (C-3) was changed to 5 parts. When the morphology of the block copolymer in the obtained resin film (8) was confirmed by the above-described measurement method, it was columnarly dispersed with a minor axis of 30 nm and a major axis of 1000 nm or more. The evaluation results are shown in Table 1. The resin film (8) had large dispersed particle diameters of the block copolymer and whitening occurred when it was bent.

[0145] (Comparative Example 2) A resin film (9) (acetone-insoluble content: 22%) was obtained in the same manner as in Example 1, except that 37 parts of the acrylic multilayer polymer (B-1) was changed to 37 parts and 10 parts of the acrylic block copolymer (C-2) was changed to 10 parts. When the morphology of the block copolymer in the obtained resin film (9) was confirmed by the above-described measurement method, it was columnarly dispersed with a minor axis of 40 nm and a major axis of 600 nm. The evaluation results are shown in Table 1. The resin film (9) had large dispersed particle diameters of the block copolymer and whitened when bent.

[0146] (Comparative Example 3) A resin film (10) (acetone-insoluble content: 37%) was obtained in the same manner as in Example 1, except that 40 parts of the acrylic multilayer polymer (B-1) was changed to 40 parts and 10 parts of the acrylic multilayer polymer (B-2) was used instead of the acrylic block copolymer. The evaluation results are shown in Table 1. The transparency of the resin film (10) deteriorated due to the influence of adding the multilayer polymer with large particle diameters.

[0147] (Comparative Example 4) A resin film (11) (acetone-insoluble content: 30%) was obtained in the same manner as in Example 1, except that 50 parts of the acrylic multilayer polymer (B-1) was changed to 50 parts and 0 part of the acrylic block copolymer was used. The evaluation results are shown in Table 1. Since the resin film (11) does not contain the block copolymer, it was predicted that it would be inferior in flexibility and prone to cracking during processing.

[0148] (Comparative Example 5) A resin film (12) (acetone-insoluble content: 54%) was obtained in the same manner as in Example 1, except that 90 parts of the acrylic multilayer polymer (B-1), 10 parts of the methacrylic resin (A-1), and 0 part of the acrylic block copolymer were used. The evaluation results are shown in Table 1. Since the resin film (12) has a high content of the multilayer polymer, it is excellent in flexibility, but the surface hardness has deteriorated.

[0149] (Comparative Example 6) A resin film (13) with a thickness of 75 μm (acetone-insoluble content: 36%) was obtained in the same manner as in Example 5, except that the lip opening was changed to 1.5 mm. When the morphology of the block copolymer in the obtained resin film (13) was confirmed by the above-described measurement method, it was found to be spherical and dispersed with a diameter of 200 nm. The evaluation results are shown in Table 1. The resin film (13) had large dispersed particle diameters of the block copolymer and whitened when bent.

[0150] (Example 8) A resin film (14) (acetone-insoluble content: 28.8% by mass) was obtained in the same manner as in Example 1, except that the pellets were changed to 48 parts of the multilayered structure polymer particles (B-1), 50 parts of the methacrylic resin (A-1), and 2 parts of the block copolymer (C-2). The evaluation results are shown in Table 1. The resin film (14) was excellent in transparency, surface hardness, moldability, and vapor deposition properties.

[0151] (Example 9) A resin film (15) (acetone-insoluble content: 39.6% by mass) was obtained in the same manner as in Example 1, except that the pellets were changed to 66 parts of the multilayered structure polymer particles (B-1), 30 parts of the methacrylic resin (A-2), and 4 parts of the block copolymer (C-2). The evaluation results are shown in Table 1. The resin film (15) was excellent in transparency, surface hardness, moldability, and vapor deposition properties.

[0152] (Example 10) A resin film (16) (acetone-insoluble content: 27.0% by mass) was obtained in the same manner as in Example 1, except that the pellets were changed to 45 parts of the multilayered structure polymer particles (B-1), 52 parts of the methacrylic resin (A-2), and 3 parts of the acrylic block copolymer (C-3). The evaluation results are shown in Table 1. The resin film (16) was excellent in transparency, surface hardness, moldability, and vapor deposition properties.

[0153] (Example 11) A resin film (17) (acetone-insoluble content: 16.8% by mass) was obtained in the same manner as in Example 1, except that the pellets were changed to 30 parts of pellets of the multilayer structure polymer particles (B-1), 66 parts of pellets of the methacrylic resin (A-1), and 4 parts of pellets of the block copolymer (C-2). The evaluation results are shown in Table 1. The resin film (17) was excellent in transparency, surface hardness, moldability, and vapor deposition property.

[0154] (Example 12) A resin film (18) (acetone-insoluble content: 27.0% by mass) was obtained in the same manner as in Example 1, except that the pellets were changed to 45 parts of pellets of the multilayer structure polymer particles (B-1), 51 parts of pellets of the methacrylic resin (A-2), and 4 parts of pellets of the acrylic block copolymer (C-4). The evaluation results are shown in Table 1. Although the haze of the resin film (18) was slightly inferior, it was excellent in surface hardness, moldability, and vapor deposition property.

[0155] (Comparative Example 7) A resin film (19) (acetone-insoluble content: 23.8% by mass) was obtained in the same manner as in Example 1, except that the pellets were changed to 36 parts of pellets of the multilayer structure polymer particles (B-2), 59 parts of pellets of the methacrylic resin (A-2), and 5 parts of pellets of the block copolymer (C-2). The evaluation results are shown in Table 1. An increase in haze was observed after heating, and cloudiness was seen in the appearance after vapor deposition and molding of the resin film (19).

[0156] (Comparative Example 8) A resin film (20) (acetone-insoluble content: 48.0% by mass) was obtained in the same manner as in Example 1, except that the pellets were changed to 80 parts of pellets of the multilayer structure polymer particles (B-1) and 20 parts of pellets of the methacrylic resin (A-2). The evaluation results are shown in Table 1. The resin film (20) had a low pencil hardness, and cloudiness was seen in the appearance after molding.

[0157] (Comparative Example 9) A resin film (21) (acetone-insoluble content: 0% by mass) was obtained in the same manner as in Example 1, except that the pellets were changed to 85 parts of pellets of methacrylic resin (A-1) and 15 parts of pellets of block copolymer (C-2). The evaluation results are shown in Table 1. The resin film (21) was very brittle and cracked during molding.

[0158] (Comparative Example 10) A resin film (22) (acetone-insoluble content: 18.0% by mass) was obtained in the same manner as in Example 1, except that the pellets were changed to 30 parts of pellets of multilayer structure polymer particles (B-1), 20 parts of pellets of methacrylic resin (A-1), and 50 parts of pellets of block copolymer (C-2). The evaluation results are shown in Table 1. The pencil hardness of the resin film (22) decreased.

[0159] [Table 1] TIFF0007693541000003.tif137170TIFF0007693541000004.tif131170TIFF0007693541000005.tif130170

[0160] The above results demonstrate that the film of the present invention is excellent in transparency, surface smoothness, anti-flexure whitening property, pencil hardness, flexibility, moldability, and appearance after molding, and is suitable for decorative applications.

Claims

1. A methacrylic resin (A) containing 80% by mass or more of methyl methacrylate units and having a weight average molecular weight of 60,000 or more and 200,000 or less, An acrylic multi-layer polymer (B) having at least one rubber component layer (b1) inside and at least one thermoplastic resin component layer (b2), with the outermost layer being the thermoplastic resin component layer (b2), and the average particle diameter of the rubber component layer (b1) being in the range of 0.05 to 0.15 μm, An acrylic block copolymer (C) containing a methacrylic acid ester polymer block (c1) and an acrylic acid ester polymer block (c2), A methacrylic melt extrusion molded article containing the above components, In the methacrylic melt extrusion molded article, the content of the methacrylic resin (A) is 20 to 52% by mass, The acetone-insoluble content of the molded article is 1 to 60% by mass. In a cross-section parallel to the extrusion direction of the molded article, the acrylic acid ester polymer block (c2) forms a columnar phase, the minor axis of the columnar phase is 1 nm or more and 100 nm or less, and the major axis of the columnar phase is 200 nm or more and 500 nm or less. In the acrylic multi-layer polymer (B), the rubber component layer (b1) contains a copolymer composed of 50 to 98.99% by mass of acrylic acid ester monomer units, 1 to 44.99% by mass of other monofunctional monomer units, and 0.01 to 10% by mass of polyfunctional monomers. The thermoplastic resin component layer (b2) contains a copolymer composed of 40 to 100% by mass of methacrylic acid ester monomer units and 60 to 0% by mass of other monomer units. In the methacrylic melt extrusion molded article, the content of the acrylic multi-layer polymer (B) is 47 to 65% by mass. The acrylic block copolymer (C) contains at least one methacrylate polymer block (c1) and at least one acrylate polymer block (c2), and the acrylic block copolymer (C) contains 30 to 60% by mass of the methacrylate polymer block (c1) and 40 to 70% by mass of the acrylate polymer block (c2). The content of the acrylic block copolymer (C) in the methacrylic melt-extruded molded article is 1 to 10% by mass. A methacrylic melt-extruded molded article, characterized in that the total content of the rubber component layer (b1) and the acrylate polymer block (c2) in the methacrylic melt-extruded molded article is 7 to 60% by mass.

2. The methacrylic melt-extruded molded article according to claim 1, wherein the methacrylic melt-extruded molded article is a film having a thickness of 20 to 200 μm.

3. The methacrylic melt-extruded molded article according to claim 1 or 2, further containing a matting agent.

4. The methacrylic melt-extruded molded article according to any one of claims 1 to 3, further comprising a functional layer.

5. The methacrylic melt-extruded molded article according to any one of claims 1 to 4, wherein the methacrylic melt-extruded molded article is a film, and the film is laminated with another thermoplastic resin film.

6. The methacrylic melt-extruded molded article according to any one of claims 1 to 5, which is for decoration.

7. The methacrylic melt-extruded molded article according to any one of claims 1 to 5, which is for building materials.

8. A method for producing a methacrylic melt-extruded molded article, comprising a step of melt-extruding a methacrylic resin composition using a T-die. The methacrylic resin composition includes a methacrylic resin (A) containing 80% by mass or more of methyl methacrylate units and having a weight average molecular weight of 60,000 or more and 200,000 or less, an acrylic multi-layer polymer (B) having at least one rubber component layer (b1) and at least one thermoplastic resin component layer (b2) inside, with the outermost layer being the thermoplastic resin component layer (b2), and the average particle diameter of the rubber component layer (b1) being in the range of 0.05 to 0.15 μm, and an acrylic block copolymer (C) containing a methacrylic ester polymer block (c1) and an acrylic ester polymer block (c2). The content of the methacrylic resin (A) in the methacrylic melt-extruded molded body is 20 to 52% by mass. The content of the acrylic multi-layer polymer (B) in the methacrylic melt-extruded molded body is 47 to 65% by mass. The methacrylic ester polymer block (c1) accounts for 30 to 60% by mass and the acrylic ester polymer block (c2) accounts for 40 to 70% by mass in the acrylic block copolymer (C), and the content of the acrylic block copolymer (C) in the methacrylic melt-extruded molded body is 1 to 10% by mass. The total content of the rubber component layer (b1) and the acrylic ester polymer block (c2) in the methacrylic melt-extruded molded body is 7 to 60% by mass. In the melt extrusion process, the shear rate applied at die discharge is in the range of 200 to 650 / s, and the ratio Dr / Dt of the die lip opening (Dr) to the thickness (Dt) of the molded body satisfies 3 ≤ Dr / Dt ≤ 10. A method for manufacturing a methacrylic melt-extruded molded body is characterized by this.

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