JP7266474B2 - METHACRYLIC RESIN COMPOSITION, MOLDED PRODUCT THEREOF, AND METHOD FOR MANUFACTURING FILM - Google Patents

Description

TECHNICAL FIELD The present invention relates to a methacrylic resin composition, a molded article thereof, and a method for producing a film.

Methacrylic resin is excellent in optical performance such as transparency and surface glossiness, and mechanical performance such as rigidity and scratch resistance. It has been used in various applications such as electronic and electrical materials. However, since methacrylic resin is a brittle material, it is generally difficult to apply it to applications that require impact strength.

In order to improve the impact strength of methacrylic resins, multi-layer structure polymer particles (so-called core-shell type polymer particles) having a rubber component layer inside and a thermoplastic resin component layer as the outermost layer are added. is preferably used. This method is currently the most widely practiced industrially.

For example, Patent Document 1 discloses a method of blending a multi-layer acrylic rubber produced by an emulsion polymerization method with a methacrylic resin. However, the effect of improving the impact strength of the methacrylic resin by this method is not sufficient, and a large amount of acrylic rubber must be added in order to satisfy the required impact strength. Addition of a large amount of acrylic rubber is not preferable because it impairs the optical performance and mechanical performance inherent in the methacrylic resin.

As a method for solving the above problems, a method of blending a block polymer with a methacrylic resin is known. For example, Patent Document 2 discloses a methacrylic resin composition comprising a methacrylic resin and a block copolymer having a methacrylic acid ester polymer block and an acrylic acid ester polymer block. Further, in Patent Document 3, a block copolymer containing a methacrylic polymer block and an acrylic polymer block is added to multi-layer structure polymer particles made of a copolymer of an acrylic acid ester and a methacrylic acid ester. A thermoplastic resin composition is disclosed.

The resin compositions described in these documents tend to improve the balance between impact strength, optical performance, and mechanical performance by finely dispersing the block polymer in the methacrylic resin, but the performance is insufficient.

Furthermore, Patent Document 4 discloses an acrylic thermoplastic resin composition containing two or more layers of multilayer structure polymer particles and a block copolymer.

Japanese Patent Publication No. 59-36645 WO2012/057079A Japanese Patent Application Laid-Open No. 2002-194167 WO2017/188290A

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a methacrylic resin composition having excellent impact strength, optical performance and mechanical performance.

The present invention provides the following methacrylic resin composition, a molded article thereof, and a method for producing a film.
[1]
In a methacrylic resin composition in which a methacrylic resin (A) forms a matrix and a rubber-like elastic body (B) is dispersed, a methacrylic resin that satisfies the following requirements (1) to (6): system resin composition.
(1) Rubber-like elastomer (B) contains multilayer structure polymer particles (a) and block copolymer (b).
(2) The multi-layer structure polymer particles (a) have at least one rubber component layer (aI) and have a hard resin component layer (aII) on the outermost layer, and the average of the rubber component layers closest to the outermost layer The particle size is in the range of 0.19-0.3 μm.
(3) The methacrylic resin composition contains 3 to 20% by mass of the rubber component layer (aI) of the multilayer structure polymer particles (a).
(4) Block copolymer (b) contains methacrylic polymer block (bII) and acrylic polymer block (bI), and acrylic polymer block (bI) is a rubber component.
(5) The total rubber component content of (aI) and (bI) in the methacrylic resin composition is in the range of 5 to 45% by mass.
(6) The content ratio of (bI) to the total rubber component content of (aI) and (bI) in the methacrylic resin composition is in the range of 5 to 90% by mass.
[2]
The multilayer structure polymer particles (a) contain 50 to 89.99% by mass of acrylic acid ester monomer units and 44.99 to 10% by mass of other monofunctional monomer units in the rubber component layer (aI). , and at least one rubber component layer (aI) containing a copolymer consisting of 0.01 to 10% by mass of polyfunctional monomer units, and the outermost layer has 50 to 100 methacrylic acid ester monomer units. % by mass and at least one hard resin component layer (aII) composed of 50 to 0 mass% of other monomer units, and the total amount of the rubber component layer (aI) and the total amount of the hard resin component layer (aII) The methacrylic resin composition according to [1], which has a mass ratio (aI/aII) of 30/70 to 90/10.
[3]
[ 1] or the methacrylic resin composition according to [2].
[4]
The methacrylic resin composition according to [3], wherein the (meth)acrylic acid aromatic ester is benzyl acrylate.
[5]
Weight average molecular weights Mw (bII) and Mw (bI) of methacrylic polymer block (bII) and acrylic polymer block (bI) of block copolymer (b) and weight average molecular weight Mw of methacrylic resin (A) The methacrylic resin composition according to any one of [1] to [4], wherein (A) satisfies the following formulas (Y) and (Z).
0.5≦Mw(A)/Mw(bII)≦2.5 (Y)
5,000≤Mw(bI)≤120,000 (Z)
[6]
A molded article containing the methacrylic resin composition according to any one of [1] to [5].
[7]
The molded article according to [6], which is an injection molded article.
[8]
A method for producing a film, comprising a step of melt-extruding or solution-casting the methacrylic resin composition according to any one of [1] to [5].

According to the present invention, it is possible to provide a methacrylic resin composition excellent in impact strength, optical performance and mechanical performance.

"Methacrylic resin composition"
The methacrylic resin composition of the present invention comprises a methacrylic resin (A) and a rubber-like elastic body (B), wherein the rubber-like elastic body (B) comprises at least one multi-layer structure polymer particle ( a) and at least one block copolymer (b).

The multilayer structure polymer particle (a) comprises at least one rubber component layer (aI) and at least one hard resin component layer (aII).

The block copolymer (b) contains at least one acrylic polymer block (bI) corresponding to the rubber component and at least one methacrylic polymer block (bII) corresponding to the hard resin component.

In this specification, the total amount of (aI) and (bI) is sometimes referred to as "rubber component content", but the methacrylic resin composition of the present invention contains rubbers other than (aI) and (bI) may contain ingredients.

The methacrylic resin composition of the present invention preferably contains 20 to 90% by mass of the methacrylic resin (A) and 10 to 80% by mass of the rubber-like elastic body (B), more preferably 30 to 30% by mass of the methacrylic resin (A). 85% by mass and 15 to 70% by mass of the rubber-like elastic body (B).

In one preferred embodiment, the methacrylic resin composition of the present invention comprises 20 to 90% by mass of methacrylic resin (A), 5 to 40% by mass of multilayer structure polymer particles (a), and block copolymer (b). 5 to 40% by mass.

In the methacrylic resin composition of the present invention, the rubber component layer (aI) of the multilayer structure polymer particles (a) is preferably 3 to 20% by mass, more preferably 3 to 18% by mass, still more preferably 3.5 to 15% by mass. Including % by mass.

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

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, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate; phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, 2-acrylate Hydroxyethyl, 2-ethoxyethyl acrylate, glycidyl acrylate, allyl acrylate; Acrylic esters such as cyclohexyl acrylate, norbornenyl acrylate, isobornyl acrylate; 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, methacryl methacrylic acid esters other than methyl methacrylate such as isobornyl acid; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride, maleic acid and itaconic acid; ethylene, propylene, 1-butene, isobutylene, 1-octene and the like Olefins; conjugated dienes such as butadiene, isoprene and myrcene; aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene and m-methylstyrene; acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl Pyridine, vinyl ketone, vinyl chloride, vinylidene chloride, vinylidene fluoride: and the like.

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

The weight average molecular weight (hereinafter referred to as Mw (A)) of the methacrylic resin (A) is preferably 30,000 or more and 1,000,000 or less, more preferably 40,000 or more and 800,000 or less, particularly preferably 50,000 or more and 500,000 or less. If Mw (A) is too small, the impact resistance and toughness of the molded article obtained from the obtained methacrylic resin composition tend to deteriorate. If the Mw (A) is too large, the fluidity of the methacrylic resin composition tends to be low and the moldability tends to be low.

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 referred to as the ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) is sometimes referred to as “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 moldability of the methacrylic resin composition tends to deteriorate. If the molecular weight distribution is too large, the impact resistance of the molded product obtained from the methacrylic resin composition tends to be low and the product tends to be brittle.

Mw (A) and Mn (A) are standard polystyrene conversion values measured by GPC (gel permeation chromatography).

Moreover, 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 the chain transfer agent.

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

In the present invention, a commercially available product may be used as the methacrylic resin (A). Examples of such commercially available methacrylic resins include "Parapet H1000B" (MFR: 22 g/10 minutes (230°C, 37.3 N)) and "Parapet GF" (MFR: 15 g/10 minutes (230°C, 37.3 N)). 3N)), “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 minutes (230° C., 37.3 N)) [all trade names, manufactured by Kuraray Co., Ltd.] and the like.

(Rubber-like elastic body (B))
The rubber-like elastic material (B) used in the present invention contains at least one multilayer structure polymer particle (a) having two or more layers and at least one block copolymer (b).

(Multilayer structure polymer particles (a))
The multilayer structure polymer particle (a) has therein at least one rubber component layer (aI) (hereinafter sometimes simply abbreviated as "(aI)") and at least one hard resin component layer. (aII) (hereinafter sometimes simply abbreviated as “(aII)”), and the outermost layer is a hard resin component layer (aII), which has a core-shell structure. In addition, the core of the multilayer structure polymer particle (a) is regarded as a "layer". The number of layers of the multilayer structure polymer particles (a) may be 2 or more, and may be 3, 4 or more. As the layer structure, from the center, a two-layer structure of (aI)-(aII); (aI)-(aI)-(aII), (aI)-(aII)-(aII), or (aII)-( A three-layer structure of aI)-(aII); a four-layer structure of (aI)-(aII)-(aI)-(aII), and the like. Among them, from the viewpoint of handleability, a two-layer structure of (aI)-(aII); a three-layer structure of (aI)-(aI)-(aII) or (aII)-(aI)-(aII) is preferable, A three-layer structure of (aII)-(aI)-(aII) is more preferable.

The mass ratio ((aI)/(aII)) of the total amount of the rubber component layer (aI) to the total amount of the hard resin component layer (aII) is 30/70 to 90/10. If the ratio of (aI) is less than the above range, the molded article of the resin composition of the present invention may have insufficient impact strength. If the ratio of (aI) exceeds the above range, it may become difficult to form a particle structure, and the melt fluidity may decrease, making kneading with other components and molding of the resin composition of the present invention difficult. The mass ratio ((aI)/(aII)) is preferably 30/70 to 80/20, more preferably 40/60 to 70/30. When the resin composition of the present invention has two or more rubber component layers (aI), the total mass ratio is calculated, and the resin composition of the present invention has two or more hard resin component layers (aII). In that case, calculate the mass ratio with the total amount.

(aI) contains 50 to 89.99% by weight of acrylate monomer units, 44.99 to 10% by weight of other monofunctional monomer units, and 0.01 to 10% of polyfunctional monomer units % by weight. The content of the acrylic acid ester monomer unit is more preferably 55 to 89.9% by mass, the content of the monofunctional monomer unit is more preferably 44.9 to 10% by mass, and the polyfunctional monomer The unit content is more preferably 0.1 to 5% by mass.

If the content of the acrylic acid ester monomer unit is less than 50% by mass, the rubber elasticity of the multilayer structure polymer particles (a) will be insufficient, and the impact strength of the molded article of the resin composition of the present invention will be insufficient. If it exceeds 89.99% by mass, it may become difficult to form a grain structure. If the content of other monofunctional monomer units is less than 10% by mass, the optical performance of the multilayer structure polymer particles may be insufficient, and if it exceeds 44.99% by mass, the multilayer structure polymer particles may The weather resistance of (a) may be insufficient. If the content of the polyfunctional monomer unit exceeds 10% by mass, the rubber elasticity of the multilayer structure polymer particles (a) becomes insufficient, and the impact strength of the molded article of the methacrylic resin composition of the present invention is reduced. If it is less than 0.01% by mass, it may become difficult to form a grain structure.

Raw material monomers for the rubber component layer (aI) are described below.

Acrylic esters include 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, esters of acrylic acid with saturated fatty alcohols (preferably C1-C18 saturated fatty alcohols) such as octyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, and octadecyl acrylate; Examples include esters with alicyclic alcohols; esters with acrylic acid such as phenylacrylate and phenols; and esters with acrylic acid such as benzylacrylate and aromatic alcohols. One or two or more acrylic acid esters can be used.

Other monofunctional monomers 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, esters of methacrylic acid with saturated fatty alcohols (preferably C1-C22 saturated fatty alcohols) such as dodecyl methacrylate, myristyl methacrylate, palmityl methacrylate, stearyl methacrylate, and behenyl methacrylate; methacrylic acid with C5 or C5 or cyclohexyl methacrylate; Esters with C6 alicyclic alcohols; Esters of methacrylic acid and phenols such as phenyl methacrylate; Methacrylic acid esters such as esters of methacrylic acid and aromatic alcohols such as benzyl methacrylate; Styrene (St), α-methyl styrene, 1-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, and halogenated styrenes; aromatic vinyl-based monomers; and vinyl cyanide-based monomers such as acrylonitrile and methacrylonitrile. Among them, styrene is preferred. Other monofunctional monomers can be used singly or in combination of two or more.

A polyfunctional monomer is a monomer having two or more carbon-carbon double bonds in the molecule. Polyfunctional monomers 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; , ethylene glycol, butanediol, and hexanediol; and diesters of dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and maleic acid with the above-mentioned unsaturated alcohols. Specifically, allyl acrylate, methallyl acrylate, allyl methacrylate (ARMA), methallyl methacrylate, allyl cinnamate, methallyl cinnamate, diallyl maleate, diallyl phthalate, diallyl terephthalate, diallyl isophthalate, divinylbenzene, ethylene Glycol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, and the like. Among them, allyl methacrylate (ALMA) is preferred. 1 type(s) or 2 or more types can be used for a polyfunctional monomer.

Layer (aII) preferably contains a copolymer consisting of 50 to 100% by mass of methacrylate ester monomer units and 50 to 0% by mass of other monomer units. The content of methacrylic acid ester monomer units is more preferably 60 to 99% by mass, more preferably 80 to 99% by mass, and the content of other monomer units is more preferably 40 to 1% by mass, more preferably is 20 to 1% by mass. If the content of the methacrylic acid ester monomer units is less than 50% by mass, the multilayer structure polymer particles (a) may have insufficient weather resistance.

Raw material monomers for the hard resin component layer (aII) are described below.

Methacrylates 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.

Other monomers include 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 esters of acrylic acid with saturated fatty alcohols (preferably C1-C18 saturated fatty alcohols) such as acrylates, octyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate and octadecyl acrylate; Esters of C6 with cycloaliphatic alcohols; styrene (St), α-methylstyrene, 1-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4 -aromatic vinyl monomers such as benzylstyrene, 4-(phenylbutyl)styrene, and halogenated styrene; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; maleimide, N-methylmaleimide, N- maleimide-based monomers such as ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-(p-bromophenyl)maleimide, and N-(chlorophenyl)maleimide; Examples thereof include the polyfunctional monomers exemplified in aI). Among them, acrylic acid alkyl esters such as methyl acrylate (MA), ethyl acrylate and n-butyl acrylate (BA) are preferred.

In the multilayer structure polymer particles (a), the weight average molecular weight (Mw) of the copolymer constituting the outermost layer (aII) is in the range of 20,000 to 100,000 as measured by the GPC method. It is preferably in the range of 30,000 to 90,000, and particularly preferably in the range of 40,000 to 80,000. If the Mw is less than 20,000, the rubber elasticity of the multi-layer structure polymer particles (a) will be insufficient, and molding of molded articles of the resin composition of the present invention may be difficult. If Mw exceeds 100,000, the impact strength of the molded article may be lowered.

The average particle size (de) of the multilayer structure polymer particles (a) rubber component layer closest to the outermost layer is in the range of 0.19 to 0.3 μm. If the average particle diameter (de) is less than 0.19 μm, the stress concentration on the multilayer structure polymer particles (a) will be insufficient, and the impact strength of the molded article may decrease. If the average particle size (de) exceeds 0.3 μm, voids are likely to occur inside the multilayer structure polymer particles (a). In addition, when the rubber content in the resin composition is constant, the number of particles decreases when the particle size increases beyond a certain level, so the distance between the surfaces of the particles tends to increase, and cracks occur in the continuous phase. The probability increases, and the impact strength of the molded product may decrease. The voids referred to here are fractures that occur only inside the particles, and since the amount of energy absorption is very small, they do not contribute much to the development of impact resistance.

From the viewpoint of stress concentration on the multilayer structure polymer particles (a), the average particle diameter (de) is preferably 0.195 to 0.25 μm, more preferably 0.20 to 0.23 μm.

The average particle size (de) of the rubber component layer (aI) of the multilayer structure polymer particles (a) can be determined by a method of measuring the resin composition with an electron microscope or a method of measuring latex by a light scattering method. can be done. In the method using an electron microscope, the rubber component layer (aII) of the dyed multi-layer structure polymer particles (a) observed with a transmission electron microscope when the resin composition of the present invention is electron-dyed with ruthenium tetroxide and is the average value of the major axis diameter and the minor axis diameter of those constituting the outermost part. In the method using the light scattering method, the latex polymerized up to the rubber component layer is sampled during the polymerization of the multi-layer structure polymer particles, and measured using a laser diffraction/scattering particle size distribution analyzer LA-950V2 manufactured by Horiba, Ltd. can.

In one preferred embodiment of the present invention, the method for producing the multilayered polymer particles (a) according to the present invention comprises a multilayered structure polymer having the rubber component layer (I)/hard resin component layer (II) as described above. The method is not particularly limited as long as it can obtain particles (a). A preferred method for producing the multi-layer structure polymer particles (a) having a three-layer structure (core-intermediate layer-outermost layer) related to the present invention is to emulsion-polymerize monomers for obtaining the polymer constituting the center core. Seed particles (i) are obtained, and seed particles (ii) are obtained by seed emulsion polymerization of a monomer for obtaining a polymer constituting the intermediate layer in the presence of the seed particles (i). and the step of obtaining seed particles (iii) by subjecting the monomers for obtaining the polymer constituting the outermost layer to seed emulsion polymerization in the presence of . The multi-layer structure polymer particles (a) having a two-layer structure or a four-layer or more layer structure may be obtained by those skilled in the art by referring to the above description of the production method for the three-layer structure multi-layer structure polymer particles (a). can be easily manufactured. The emulsion polymerization method or the seed emulsion polymerization method is a technique well known in the technical field as a technique for obtaining general multi-layer structure polymer particles, and therefore other documents can be referred to for detailed explanations. In the above preferred example, the seed particles (i) are single-layered particles composed of the hard resin component layer (aII, core), and the seed particles (ii) are the hard resin component layer (aII, core) + rubber component. It is a particle having a two-layer structure of a layer (aI, intermediate layer), and seed particles (iii) are hard resin component layer (aII, core) + rubber component layer (aI, intermediate layer) + hard resin component layer (aII, maximum layer). outer layer).

In the polymerization reaction step, the polymerization conditions are adjusted so that Mw of the copolymer constituting at least the outermost hard resin component layer (aII) is 20,000 to 100,000. The polymerization conditions are adjusted mainly by adjusting the amount of the molecular weight modifier such as alkyl mercaptan. Polymerization in all the polymerization reaction steps is carried out so that the average particle diameter of the finally obtained multilayer structure polymer particles (a) to the outermost hard resin component layer (aII) is in the range of 0.2 to 0.35 μm. Adjust conditions.

The average particle diameter up to the outermost hard resin component layer (aII) in the multilayer structure polymer particles (a) was obtained by sampling the polymerized latex at the time of polymerization of the multilayer structure polymer particles, and measuring the laser diffraction/ It can be measured by a light scattering method using a scattering type particle size distribution analyzer LA-950V2.

(Block copolymer (b))
The block copolymer (b) used in the present invention has a methacrylate polymer block (bII) and an acrylate polymer block (bI). The block copolymer (b) may have one or more methacrylate polymer blocks (bII). Moreover, the block copolymer (b) may have only one acrylic acid ester polymer block (bI), or may have a plurality of them. Such a block copolymer (b) has good compatibility with the methacrylic resin (A) and the multilayer structure polymer particles (a).

From the viewpoint of compatibility, the block copolymer (b) includes 10 to 80% by mass of a polymer block (bII) having methacrylate monomer units and a polymer block (bII) having mainly acrylic ester monomer units. A block copolymer containing 90 to 20% by mass of coalescing block (bI) (provided that the total amount of polymer block (bII) and polymer block (bI) is 100% by mass) is preferred. In the block copolymer (b), the content of polymer block (bII) is more preferably 20 to 70% by mass, more preferably 30 to 60% by mass, and the content of polymer block (bI) is more preferably 80 to 30% by mass, more preferably 70 to 40% by mass.

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

Polymer block (bII) contains mainly methacrylate monomer units. The content of the methacrylate monomer units in the polymer block (bII) 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 may be composed only of methacrylic acid ester monomer units.

Raw material monomers for the methacrylic polymer block (bII) are described below.

Methacrylic acid esters 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) and the like. Among them, from the viewpoint of improving the transparency and heat resistance of the methacrylic resin composition of the present invention, methyl methacrylate (MMA), ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, and isobol Nil methacrylate and the like are preferred, and methyl methacrylate (MMA) is particularly preferred. One or two or more methacrylic acid esters can be used.

The weight-average molecular weight (Mw(bII)) of the methacrylic polymer block (bII) has a lower limit of preferably 5,000, more preferably 8,000, even more preferably 12,000, particularly preferably 15,000, and most preferably 15,000. It is preferably 20,000, and the upper limit is preferably 150,000, more preferably 120,000, and particularly preferably 100,000. When the block copolymer (b) has multiple polymer blocks (bII), the weight average molecular weight (Mw(bII)) is the total amount of Mw of the multiple polymer blocks (bII).

In a preferred embodiment of the present invention, the weight average molecular weight Mw (bII) of the methacrylic polymer block (bII) of the block copolymer (b) and the weight average molecular weight Mw (A) of the methacrylic resin (A) are , satisfies the following equation (Y).
0.5≦Mw(A)/Mw(bII)≦2.5 (Y)

The ratio of the weight average molecular weight Mw(A) to Mw(bII) of the methacrylic resin (A), that is, Mw(A)/Mw(bII) is 0.5 or more and 2.5 or less, preferably 0.6 or more and 2.5. 3 or less, more preferably 0.7 or more and 2.2 or less. If Mw(A)/Mw(bII) is too small, the impact strength of the molded article produced from the resin composition tends to be low. On the other hand, if Mw(A)/Mw(bII) is too large, the surface smoothness and transparency of the plate-like molded article produced from the resin composition tend to deteriorate. When Mw(A)/Mw(bII) is within the above range, the dispersed particle size of the block copolymer (b) in the methacrylic resin (A) is small, resulting in excellent transparency.

The content of the methacrylic polymer block (bII) in the block copolymer (b) determines the transparency, flexibility, flexibility, flex resistance, and impact resistance of the molded article of the thermoplastic resin composition of the present invention. From the viewpoint of properties, moldability, and surface smoothness, it is preferably 10 to 80% by mass, more preferably 20 to 70% by mass. When the block copolymer (b) has multiple polymer blocks (bII), the content of the polymer blocks (bII) is the total content of the multiple polymer blocks (bII).

In one preferred embodiment of the present invention, the acrylic polymer block (bI) mainly contains acrylate ester monomer units. The content of acrylic acid ester monomer units in the acrylic polymer block (bI) 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.

Raw material monomers for the acrylic polymer block (bI) are described below.

Acrylic acid esters 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 acrylates, 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 etc. One or two or more acrylic acid esters can be used.

In another preferred embodiment of the present invention, from the viewpoint of the transparency of the resin composition of the present invention, the acrylic polymer block (bI) is composed of acrylic acid alkyl ester monomer units and (meth)acrylic acid Polymer blocks (bI-p) containing aromatic hydrocarbon ester monomer units are preferred. Here, the content of the acrylic acid alkyl ester monomer unit in the polymer block (bI) is preferably 50 to 90% by mass, more preferably 60 to 80% by mass. The content of hydrogen ester monomer units is preferably 50 to 10% by mass, more preferably 40 to 20% by mass.

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

The lower limit of the weight average molecular weight Mw (bI) of the acrylic polymer block (bI) is preferably 5,000, more preferably 15,000, still more preferably 20,000, particularly preferably 30,000, most preferably 40,000, and the upper limit is preferably 120,000, more preferably 110,000, and particularly preferably 100,000. If the Mw(bI) is too small, the impact resistance of the molded product of the methacrylic resin composition of the present invention may be lowered. On the other hand, if the Mw(bI) is too large, the surface smoothness of the molded article of the resin composition of the present invention may be deteriorated. When the block copolymer (b) has multiple polymer blocks (bI), the weight average molecular weight Mw (bI) is the total amount of Mw of the multiple polymer blocks (bI).

The content of the acrylic polymer block (bI) in the block copolymer (b) determines the transparency, flexibility, flexibility, flex resistance, and impact resistance of the molded article of the methacrylic resin composition of the present invention. From the viewpoint of properties, moldability, and surface smoothness, it is preferably 10 to 90% by mass, more preferably 20 to 80% by mass. When the block copolymer (b) has multiple polymer blocks (bI), the content of the polymer blocks (bI) is the total content of the multiple acrylic polymer blocks (bI).

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

Among them, diblock copolymers and triblock copolymers are preferred, and diblock copolymers having a (bII)-(bI) structure and triblock copolymers having a (bII)-(bI)-(bII) structure are more preferred.

The block copolymer (b) may optionally have functional groups such as hydroxyl groups, carboxyl groups, acid anhydride groups, and amino groups in the molecular chain and/or at the ends of the molecular chain.

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

The block copolymer (b) has a ratio (Mw(b)/Mn(b)) between a weight average molecular weight (Mw(b)) and a number average molecular weight (Mn(b)) of preferably 1.0 to 2. .0, more preferably 1.0 to 1.6. When Mw(b)/Mn(b) is within the above range, the amount of unmelted material during melt kneading of raw materials in the production of a resin composition, which causes lumps in molded articles, is extremely small. can be done.

The method for producing the block copolymer (b) is not particularly limited, and a method of living polymerization of each polymer block is common. Examples of the living polymerization method include a method of anionic polymerization 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, and an organic aluminum compound using an organic alkali metal compound as a polymerization initiator. Examples include a method of anionic polymerization in the presence of a compound, a method of polymerization using an organic rare earth metal complex as a polymerization initiator, and a method of radical polymerization in the presence of a copper compound using an α-halogenated ester compound as a polymerization initiator. Moreover, the method of superposing|polymerizing using a polyvalent radical polymerization initiator or a polyvalent radical chain transfer agent is also mentioned. Among them, the block copolymer (b) can be obtained with high purity, the composition and molecular weight of each block can be easily controlled, and it is economical. A method of anionic polymerization in the presence is particularly preferred.

The refractive index of the block copolymer (b) 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 thermoplastic resin composition of the present invention has high transparency. In this specification, "refractive index" means a value measured at a wavelength of 587.6 nm (D line).

A resin composition excellent in transparency and impact strength is obtained by adding the multilayer structure polymer particles (a) related to the present invention to the step of mixing the methacrylic resin (A) and the block copolymer (b) and kneading them. can be obtained. The methacrylic resin (A), the multilayer structure polymer particles (a) and the block copolymer (b) can be mixed by the following four methods, any of which may be selected.
(i) A two-stage mixing method in which the methacrylic resin (A) and the multilayer structure polymer particles (a) are first mixed, and then the block copolymer (b) is mixed in the mixture of (A) + (a);
(ii) A two-stage mixing method in which the methacrylic resin (A) and the block copolymer (b) are first mixed, and the mixture of (A) + (b) is mixed with the multilayer structure polymer particles (a);
(iii) A two-stage mixing method in which the multilayer structure polymer particles (a) and the block copolymer (b) are first mixed, and the methacrylic resin (A) is mixed in the mixture of (a) + (b);
(iv) A method of mixing the methacrylic resin (A), the multilayer structure polymer particles (a) and the block copolymer (b) in one step.

As a kneading method, known methods such as kneading using a batch type kneader such as a Banbury mixer, a pressure kneader, Prabender Plastograph, or a continuous kneader such as a single-screw, twin-screw or multi-screw extruder. It can be carried out. Alternatively, a method of once producing high-concentration master pellets by the above method and then diluting them and melt-kneading them may be used. From the viewpoint of productivity, a single-screw system or a twin-screw system is preferred. In particular, a single-screw extruder is preferable because it imparts less shearing energy to the resin composition.

(rubber content)
In the methacrylic resin composition of the present invention, the total amount of the rubber component layer (aI) of the multilayer structure polymer particles (a) and the acrylic polymer block (bI) of the block copolymer (b) is 5 to 45. % by mass, preferably 6 to 40% by mass, more preferably 7 to 30% by mass. If the total amount of the rubber component layer (aI) and the acrylic polymer block (bI) is less than 1% by mass, the impact strength will deteriorate, and if it exceeds 45% by mass, the rigidity will deteriorate.

(bI rubber ratio)
In the methacrylic resin composition of the present invention, the content ratio of the acrylic polymer block (bI) to the total rubber content of (aI) and (bI) is in the range of 5 to 90 mass%, and 10 to 85 mass. %, more preferably 15 to 80% by mass. When the content ratio of the acrylic polymer block (bI) to the rubber content is in the range of 5 to 90% by mass, the synergistic effect of the multilayer structure polymer particles and the block copolymer works, resulting in excellent impact strength. .

(Optional component)
The thermoplastic resin composition of the present invention may optionally contain other polymers in addition to the methacrylic resin (A) and the rubber elastic body (B) within a range that does not impair the effects of the present invention. good. Other polymers include olefinic resins such as polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, and polynorbornene; ethylene ionomers; polystyrene, styrene-maleic anhydride copolymers, high impact Styrene resins such as polystyrene, AS resin, ABS resin, AES resin, AAS resin, ACS resin, and MBS resin; Methyl methacrylate-styrene copolymer; Ester resins such as polyethylene terephthalate and polybutylene terephthalate; Nylon 6; Nylon 66, and amide resins such as polyamide elastomers; polyphenylene sulfide, polyetheretherketone, polysulfone, polyphenylene oxide, polyimide, polyetherimide, polycarbonate, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polyvinyl alcohol, ethylene- Other thermoplastic resins such as vinyl alcohol copolymers, polyacetals, and phenoxy-based resins; thermosetting resins such as phenolic-based resins, melamine-based resins, silicone-based resins, and epoxy-based resins; polyurethanes; modified polyphenylene ethers; modified resins; acrylic rubbers, silicone rubbers; styrenic thermoplastic elastomers such as SEPS, SEBS and SIS; olefinic rubbers such as IR, EPR and EPDM. Other polymers can be used alone or in combination of two or more.

The methacrylic resin composition of the present invention may contain various additives as necessary. Additives include antioxidants, heat deterioration inhibitors, UV absorbers, light stabilizers, lubricants, release agents, polymer processing aids, antistatic agents, flame retardants, dyes/pigments, light diffusing agents, gloss erasing agents, anti-sticking agents, impact modifiers, phosphors, and the like. The content of these additives can be appropriately set within a range that does not impair the effects of the present invention. 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, and the content of the dye/pigment is 0.01 to 3 parts by mass, and the anti-adhesion 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 weight.

Antioxidants are effective by themselves to prevent oxidation deterioration of resins in the presence of oxygen. Examples include phosphorus antioxidants, phenolic antioxidants, sulfur antioxidants, and amine antioxidants. Among them, from the viewpoint of preventing deterioration of optical properties due to coloring, phosphorus antioxidants and phenolic antioxidants are preferable, and phenolic antioxidants are used alone or in combination with phosphorus antioxidants and phenolic antioxidants. Combined use is more preferred. When a phosphorus antioxidant and a phenolic antioxidant are used in combination, it is preferable to use the phosphorus antioxidant/phenolic antioxidant at a mass ratio of 0.2/1 to 2/1, and 0.2/1 to 2/1. It is more preferable to use 5/1 to 1/1.

Phosphorus-based antioxidants include 2,2-methylenebis(4,6-di-t-butylphenyl)octyl phosphite (manufactured by ADEKA Co., Ltd. "ADEKA STAB HP-10"), tris (2,4-di-t -butylphenyl) phosphite ("IRGAFOS168" 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 (“ADEKA STAB PEP-36” manufactured by ADEKA Co., Ltd.) and the like are preferable.

Phenolic antioxidants include pentaerythrityl-tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate] (manufactured by BASF Japan Ltd. "IRGANOX1010"), and octadecyl-3- (3,5-Di-t-butyl-4-hydroxyphenyl) propionate (“IRGANOX1076” manufactured by BASF Japan Ltd.) and the like are preferred.

Preferred sulfur-based antioxidants include dilauryl 3,3'-thiodipropionate, distearyl 3,3'-thiodipropionate, pentaerythritol tetrakis(3-laurylthiopropionate), and the like.

As the amine-based antioxidant, octylated diphenylamine and the like are preferable.

The thermal degradation inhibitor can prevent thermal degradation of the resin by capturing polymer radicals generated when exposed to high temperatures under substantially oxygen-free conditions. As the heat deterioration inhibitor, 2-t-butyl-6-(3'-t-butyl-5'-methyl-hydroxybenzyl)-4-methylphenyl acrylate ("Sumilizer GM" manufactured by Sumitomo Chemical Co., Ltd.), and 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. preferable.

A UV absorber is a compound that is said to have an ability to absorb UV rays and mainly has the function of converting light energy into heat energy. Examples of UV absorbers include benzophenones, benzotriazoles, triazines, benzoates, salicylates, cyanoacrylates, oxalic acid anilides, malonic acid esters, and formamidines. Among them, benzotriazoles and triazines are preferred. 1 type(s) or 2 or more types can be used for an ultraviolet absorber.

Benzotriazoles are highly effective in suppressing deterioration of optical properties such as coloration due to exposure to ultraviolet light, and are suitable for optical applications of the thermoplastic resin composition of the present invention. 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 (manufactured by BASF Japan Ltd., "trade name TINUVIN329"), 2-(2H-benzotriazol-2-yl)-4,6-bis ( 1-methyl-1-phenylethyl)phenol (manufactured by BASF Japan Ltd. under the trade name TINUVIN234), and 2,2′-methylenebis[6-(2H-benzotriazol-2-yl)-4-t-octylphenol] (“ADEKA STAB LA-31” manufactured by ADEKA Co., Ltd.) and the like are preferable.

Further, when it is desired to efficiently absorb a wavelength around 380 nm, a triazine-based ultraviolet absorber is preferably used. Examples of such ultraviolet absorbers include 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-1,3,5-triazine (manufactured by ADEKA Co., Ltd., "ADEKA STAB LA-F70 ”), and its analogues, hydroxyphenyltriazine-based UV absorbers (“TINUVIN477” and “TINUVIN460” manufactured by BASF Japan Ltd.).

A photostabilizer is a compound that is said to have a function of scavenging radicals generated mainly by oxidation by light. Suitable light stabilizers include hindered amines such as compounds having a 2,2,6,6-tetraalkylpiperidine skeleton. Examples thereof include bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate ("ADEKA STAB LA-77Y" manufactured by ADEKA Co., Ltd.).

A lubricant is a compound that is said to have the effect of adjusting the slippage between a resin and a metal surface and preventing adhesion or sticking to improve releasability, processability, and the like. Examples include higher alcohols, hydrocarbons, fatty acids, fatty acid metal salts, fatty amides, and fatty acid esters. Among them, from the viewpoint of compatibility with the thermoplastic resin composition of the present invention, 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 preferable because they are expected to have a slip effect due to adhesion prevention. Examples of unsaturated aliphatic amides include N,N'-ethylenebisoleic acid amide ("Slipax O" manufactured by Nippon Kasei Co., Ltd.) and N,N'-dioleyladipate amide ("Slipax ZOA" manufactured by Nippon Kasei Co., Ltd.). ”) and the like.

Release agents include higher alcohols such as cetyl alcohol and stearyl alcohol; glycerin higher fatty acid esters such as stearic acid monoglyceride and stearic acid diglyceride; In the present invention, it is preferable to use higher alcohols and glycerin fatty acid monoester in combination as the release agent. When higher alcohols and glycerin fatty acid monoesters are used in combination, the ratio is not particularly limited, but the amount of higher alcohols used: the amount of glycerin fatty acid monoesters used is in a mass ratio of 2.5:1 to 3.5. 5:1 is preferred, and 2.8:1 to 3.2:1 is more preferred.

A polymer processing aid is a compound that exerts an effect on thickness accuracy and thinning when molding a methacrylic resin composition. Polymeric processing aids are typically polymer particles having a particle size of 0.05 to 0.5 μm, which can be produced by emulsion polymerization methods.

Antistatic agents include sodium heptylsulfonate, sodium octylsulfonate, sodium nonylsulfonate, sodium decylsulfonate, sodium dodecylsulfonate, sodium cetylsulfonate, sodium octadecylsulfonate, sodium diheptylsulfonate, heptylsulfonic acid Potassium, potassium octylsulfonate, potassium nonylsulfonate, potassium decylsulfonate, potassium dodecylsulfonate, potassium cetylsulfonate, potassium octadecylsulfonate, potassium diheptylsulfonate, lithium heptylsulfonate, lithium octylsulfonate, nonylsulfonate Alkyl sulfonates such as lithium oxide, lithium decylsulfonate, lithium dodecylsulfonate, lithium cetylsulfonate, lithium octadecylsulfonate, and lithium diheptylsulfonate.

Examples of flame retardants include magnesium hydroxide, aluminum hydroxide, hydrated aluminum silicate, hydrated magnesium silicate, metal hydrates having hydroxyl groups or water of crystallization such as hydrotalcite, and phosphoric acids such as amine polyphosphate and phosphate esters. trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, tricyclohexyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, dimethylethyl Phosphate flame retardants such as phosphate, methyldibutyl phosphate, ethyldipropyl phosphate and hydroxyphenyldiphenyl phosphate are preferred.

Dyes and pigments include red organic pigments such as para red, fire red, pyrazolone red, thioindicole 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. Pigments may be mentioned, and one or more of these may be used.

Light diffusing agents and matting agents include fine glass particles, polysiloxane-based crosslinked fine particles, crosslinked polymer fine particles, talc, calcium carbonate, barium sulfate, and the like. The copolymer of the present invention preferably does not contain an acid generator.

Anti-adhesion agents include fatty acids such as stearic acid and palmitic acid; fatty acid metal salts such as calcium stearate, zinc stearate, magnesium stearate, potassium palmitate and sodium palmitate; polyethylene wax, polypropylene wax, montanic acid wax and the like. waxes; Low molecular weight polyolefins such as low molecular weight polyethylene and low molecular weight polypropylene; Acrylic resin powder; Polyorganosiloxane such as dimethylpolysiloxane; powder, fluororesin powder such as tetrafluoroethylene resin, molybdenum disulfide powder, silicone resin powder, silicone rubber powder, silica and the like.

Examples of impact modifiers include core-shell modifiers containing diene rubber as a core layer component; modifiers containing a plurality of rubber particles, and the like.

Examples of phosphors include fluorescent pigments, fluorescent dyes, fluorescent white dyes, fluorescent whitening agents, and fluorescent bleaching agents.

When the methacrylic resin composition of the present invention contains other polymers and/or additives, the methacrylic resin (A) and/or the rubbery elastomer (B) (multilayer structure polymer particles (a) and/or Alternatively, it may be added during the polymerization of the block copolymer (b)), or the methacrylic resin (A) and/or the rubbery elastomer (B) (multilayer structure polymer particles (a) and/or block copolymer It may be added at the time of mixing with the coalescence (b)), or the methacrylic resin (A) and/or the rubbery elastomer (B) (multilayer structure polymer particles (a) and/or block copolymer (b) )) may be added after mixing.

The methacrylic resin composition of the present invention can be molded using a molding method and molding apparatus generally used for thermoplastic polymers. For example, a molded product can be produced by a molding method involving heating and melting such as injection molding, extrusion molding, compression molding, blow molding, calendar molding, vacuum molding, or a solution casting method.

The methacrylic resin composition of the present invention is also useful as a film. be. In addition, if necessary, by simultaneously contacting both sides of the film with a roll or a metal belt, in particular, by simultaneously contacting a roll or a metal belt heated to a temperature higher than the glass transition temperature, the film has a better surface property. It is also possible to obtain In addition, depending on the purpose, it is also possible to modify the film by laminate molding or biaxial stretching.

The film obtained from the methacrylic resin composition of the present invention can be used by laminating it on metal, plastic or the like. Examples of lamination methods include wet lamination in which an adhesive is applied to a metal plate such as a steel plate and then a film is placed on the metal plate, dried, and laminated, dry lamination, extrusion lamination, hot melt lamination, and the like.

As a method of laminating a film on a plastic part, the film is placed in a mold and filled with resin by injection molding, such as film insert molding, laminate injection press molding, or preforming the film and then placing it in the mold. Examples include film in-mold molding in which a film is arranged and resin is filled by injection molding.

The thermoplastic methacrylic resin composition of the present invention and molded articles containing the same can be used as members for various uses. Specific applications include, for example, billboard parts and marking films such as advertising towers, stand signs, sleeve signs, transom signs, and rooftop signs; display parts such as showcases, partitions, and store displays; fluorescent lamp covers, and mood lighting. Lighting parts such as covers, lamp shades, light ceilings, light walls, chandeliers; Interior parts such as furniture, pendants, mirrors; architectural parts; aircraft windshields, pilot visors, motorcycles, motorboat windshields, light shielding plates for buses, automotive side visors, rear visors, head wings, headlight covers, sunroofs, glazing, automotive interior materials, automotive exterior materials such as bumpers Parts related to transportation equipment such as: nameplates for audiovisual equipment, stereo covers, protective masks for TV sets, parts for electronic equipment such as vending machines, mobile phones, and personal computers; parts for medical equipment such as incubators and X-ray parts; machine covers, instrument covers, Equipment-related parts such as experimental equipment, rulers, dials, and observation windows; optical-related parts such as liquid crystal protection plates, light guide plates, light guide films, Fresnel lenses, lenticular lenses, front panels of various displays, and diffusion plates; Traffic-related parts such as information boards, curved mirrors, soundproof walls, etc.; Others, greenhouses, large water tanks, box water tanks, bathroom parts, clock panels, bathtubs, sanitary goods, desk mats, game parts, toys, face protection masks during welding, Examples include back sheets for solar cells, front sheets for flexible solar cells; surface materials used for personal computers, mobile phones, furniture, vending machines, bathroom members, and the like.

On the other hand, laminate laminates of films obtained from the methacrylic resin composition of the present invention include interior and exterior materials for automobiles, daily necessities, wallpaper, paint substitutes, housings for furniture and electrical equipment, and OA equipment such as facsimiles. It can be used for housings, floor coverings, parts of electrical or electronic devices, bathroom fixtures and the like.

As explained above, the methacrylic resin composition of the present invention contains a methacrylic resin (A) and a rubber-like elastic body (B). The rubber-like elastic body (B) contains the multilayer structure polymer particles (a) and the block copolymer (b), and the average particle diameter of the rubber component layer closest to the outermost layer is in the range of 0.19 to 0.3 μm. Since the impact strength of the methacrylic resin can be effectively increased with a small rubber content, the methacrylic resin composition of the present invention is excellent in impact strength, optical performance and mechanical performance. I can provide the film.

Production examples and examples according to the present invention and comparative examples will be described below.

[Evaluation items and evaluation methods]
Evaluation items and evaluation methods in Production Examples, Examples and Comparative Examples are as follows.
(Weight average molecular weight (Mw), molecular weight distribution (Mw/Mn))
The weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn) of the resin were obtained by GPC method (gas chromatography method). Tetrahydrofuran was used as the eluent. As a column, two TSKgel SuperMultipore HZM-M manufactured by Tosoh Corporation and SuperHZ4000 connected in series were used. As a GPC apparatus, HLC-8320 (product number) manufactured by Tosoh Corporation equipped with a differential refractive index detector (RI detector) was used. A sample solution was prepared by dissolving 4 mg of the resin to be measured in 5 ml of tetrahydrofuran. The temperature of the column oven was set to 40° C., 20 μl of the sample solution was injected into the device at an eluent flow rate of 0.35 ml/min, and the chromatogram was measured. Ten points of standard polystyrene having a molecular weight in the range of 400 to 5,000,000 were subjected to GPC measurement to prepare a calibration curve showing the relationship between retention time and molecular weight. Based on this calibration curve, Mw and Mw/Mn of the resin to be measured were determined.

Regarding the measurement of the multi-layer structure polymer particles (a), after the dried multi-layer structure polymer particles were immersed in acetone for 24 hours, the acetone solution was centrifuged to separate the acetone-insoluble matter from the acetone-soluble matter. The Mw of the separated and solidified acetone-soluble portion (outermost hard resin component layer (aII)) was measured.

Further, the weight average molecular weights Mw (bI) and Mw (bII) of the acrylic polymer block (rubber component, bI) and the methacrylic polymer block (hard resin component, bII) of the block copolymer (b) was measured as follows.

Mw (bII) was determined by sampling the polymer contained in the reaction solution obtained by polymerizing the methacrylic polymer block (hard resin component, bII) and measuring Mw. Next, the polymer contained in the reaction solution in which the acrylic polymer block (rubber component, bI) was polymerized was sampled, Mw was measured, and Mw (bI) was determined by subtracting Mw (bII). Mw was measured in the same manner when further methacrylic polymer or acrylic polymer block was polymerized, and the total Mw of each polymer block was defined as Mw (bI) and Mw (bII), respectively.

(Volume average particle size)
The volume average particle size of the latex containing the multilayer structure polymer particles was determined by a light scattering method using a laser diffraction/scattering particle size distribution analyzer LA-950V2 manufactured by Horiba, Ltd. The volume average particle diameter (de) up to the rubber component layer (aI) was obtained by sampling the latex after polymerization of the rubber component layer and measuring the volume average particle diameter. The average particle size up to the outermost layer was obtained by sampling the latex after polymerization of the outermost layer and measuring the volume average particle size.

(Copolymer composition)
Using a nuclear magnetic resonance spectrum ( ¹ H-NMR spectrum), analysis was performed under the following conditions.
Apparatus: Nuclear magnetic resonance apparatus "JNM-LA400" manufactured by JEOL Ltd.
Heavy solvent: deuterated chloroform

(total light transmittance, haze)
The total light transmittance and haze of the injection-molded or press-molded samples were measured according to JIS-K7361 using a spectral color difference meter (“SE5000” manufactured by Nippon Denshoku Industries Co., Ltd.).

(flexural modulus)
An injection-molded or press-molded sample was subjected to three-point bending at 23° C. using an autograph (manufactured by Shimadzu Corporation) according to JIS-K7171, and the bending elastic modulus (MPa) was measured.

(Charpy impact value)
The impact value (without notch) of injection-molded or press-molded samples was measured by a method according to JIS-K7111 under conditions of a temperature of 23° C. and a relative humidity of 50%. Measurement was performed 10 times, and the average value was adopted as the Charpy impact value.

(mass of each layer or block)
The mass of the rubber component layer (aI) and the hard resin component layer (aII) of the multilayer structure polymer particles (a) is the weight of the monomer or monomer mixture, since almost all of the monomers used have reacted. Calculated based on mass. The mass of the acrylic polymer block (bI) and the methacrylic polymer block (bII) of the block copolymer was obtained by sampling the reaction solution during polymerization of each polymer block and measuring the nuclear magnetic resonance spectrum ( ¹ H-NMR spectrum). ) was used.

[material]
Raw materials used in Examples and Comparative Examples are as follows.
(Methacrylic resin (A))
Methacrylic resin (A-1): consisting of methyl methacrylate (MMA) units (99.3% by mass content) and methyl acrylate (MA) units (0.7% by mass content), Mw = 84,000, Mw A methacrylic copolymer having /Mn=2.1.
Methacrylic resin (A-2): consisting of methyl methacrylate (MMA) units (93.6% by mass content) and methyl acrylate (MA) units (6.4% by mass), Mw = 120,000, Mw/Mn = 2.1 methacrylic copolymer.
Methacrylic resin (A-3): consisting of methyl methacrylate (MMA) units (93.6% by mass content) and methyl acrylate (MA) units (6.4% by mass), Mw = 200,000, Mw/Mn = 2.4 methacrylic copolymer.

In addition, "part" means a "mass part" below.

(Rubber-like elastic body (B))
(multilayer structure polymer particles (a));
Production Example 1; Multilayer Structure Polymer Particles (Ba-1):
100 parts of ion-exchanged water was placed in a glass-lined reaction vessel equipped with a condenser, thermometer and stirrer, and then a surfactant (sodium polyoxyethylene alkyl ether acetate (NIKKOL-ECT-3NEX)) was added. 019 parts and 0.10 parts sodium carbonate were added and dissolved. The inside of the reaction vessel was replaced with nitrogen gas to make it substantially free of oxygen. After that, the inside of the reaction vessel was heated to bring the aqueous solution to 80°C.

0.04 parts of potassium persulfate was added to the aqueous solution, and a mixture c consisting of 32.6 parts of methyl methacrylate, 2.1 parts of methyl acrylate and 0.07 parts of allyl methacrylate was added continuously over 50 minutes. bottom. Emulsion polymerization was carried out for 40 minutes after the end of the addition of the mixture c to obtain a latex c.

Next, 0.05 part of potassium persulfate was added to latex c, and a mixture i consisting of 36.6 parts of butyl acrylate, 7.9 parts of styrene and 0.89 parts of allyl methacrylate was continuously added over 60 minutes. added. After the addition of the mixture i was completed, the mixture was maintained for 90 minutes, and seed emulsion polymerization was carried out to obtain a latex i.

Next, 0.02 part of potassium persulfate was added to this latex i, and a mixture o consisting of 18.6 parts of methyl methacrylate, 1.2 parts of methyl acrylate and 0.04 part of n-octyl mercaptan was added for 30 minutes. added without interruption. After the addition of the mixture o was completed, the mixture was held for 60 minutes, and seed emulsion polymerization was carried out to obtain a latex I-1. After latex I-1 was placed in a container equipped with a stirrer and mixed, an aqueous solution of magnesium sulfate was added to cause salting-out coagulation. The coagulate was washed with water, dehydrated and dried to obtain multilayer structure polymer particles (a-1). Table 1 shows the physical properties of the multilayer structure polymer particles (a-1).

Production Example 2; Multilayer Structure Polymer Particles (Ba-2):
100 parts of ion-exchanged water was placed in a glass-lined reaction vessel equipped with a condenser, thermometer and stirrer, and then 0.019 parts of a surfactant ("Pelex SS-H" manufactured by Kao Corporation) and carbonic acid were added. 0.5 part of sodium was added and dissolved. The inside of the reaction vessel was replaced with nitrogen gas to make it substantially free of oxygen. After that, the inside of the reaction vessel was heated to bring the aqueous solution to 80°C.

To the aqueous solution, 0.02 part of potassium persulfate was added, and a mixture c consisting of 9.4 parts of methyl methacrylate, 0.6 parts of methyl acrylate and 0.02 parts of allyl methacrylate was continuously added over 20 minutes. bottom. Emulsion polymerization was carried out for 30 minutes after the end of the addition of the mixture c to obtain a latex c.

Next, 0.07 part of potassium persulfate was added to latex c, and a mixture i consisting of 41.1 parts of butyl acrylate, 8.9 parts of styrene and 2.0 parts of allyl methacrylate was continuously added over 80 minutes. added. After the addition of the mixture i was completed, the mixture was maintained for 60 minutes, and seed emulsion polymerization was performed to obtain a latex i.

Then, to this latex i, a further mixture o consisting of 37.6 parts methyl methacrylate, 2.4 parts methyl acrylate and 0.12 parts n-octyl mercaptan was added continuously over a period of 60 minutes. After the addition of the mixture o was completed, the mixture was held for 60 minutes, and seed emulsion polymerization was carried out to obtain a latex I-2. After latex I-2 was placed in a container equipped with a stirrer and mixed, an aqueous solution of magnesium sulfate was added to cause salting-out coagulation. The coagulate was washed with water, dehydrated and dried to obtain multilayer structure polymer particles (Ba-2). Table 1 shows the physical properties of the multilayer structure polymer particles (Ba-2).

Production Example 3; Multilayer Structure Polymer Particles (Ba-3):
Under a nitrogen atmosphere, 150 parts by mass of distilled water, 1.3 parts by mass of an emulsifier ("Neopelex G-15" manufactured by Kao Corporation), and a dispersant (Kao 1.0 parts by mass of "Poise 520" manufactured by Co., Ltd.) was added and heated to 80° C. to dissolve uniformly. Then, at the same temperature, after adding 0.05 parts by mass of potassium peroxodisulfate, 41.25 parts by mass of n-butyl acrylate (BA) as an acrylic acid ester monomer, other monofunctional monomers 8.75 parts by mass of styrene (St) as a polyfunctional monomer, allyl methacrylate (ALMA) 0.3 parts by mass, and a surfactant (ADEKA Co., Ltd. "ADEKA COL CS-141E") 0.25 mass The mixture consisting of the three parts was dropped from the dropping funnel over 60 minutes to form the first layer (layer (Ia)). After completion of dropping, the reaction was continued at 80° C. for an additional hour, and it was confirmed by gas chromatography that 99% or more of each monomer was consumed.

Next, after adding 0.02 parts by mass of potassium peroxydisulfate to the obtained copolymer latex, 15.81 parts by mass of n-butyl acrylate (BA) as an acrylic ester monomer, other monofunctional 3.19 parts by weight of styrene (St) as a monomer, 1.0 parts by weight of methyl methacrylate (MMA) as another monofunctional monomer, and 0 allyl methacrylate (ALMA) as a multifunctional monomer A mixture of 0.16 parts by mass and 0.1 part by mass of a surfactant (“ADEKACOL CS-141E”) was added dropwise from the dropping funnel over 40 minutes to form a second layer (layer (Ib)). After completion of dropping, the reaction was continued at 80° C. for an additional hour, and it was confirmed by gas chromatography that 99% or more of each monomer was consumed.

Next, after adding 0.03 parts by mass of potassium peroxodisulfate to the obtained copolymer latex, 28.5 parts by mass of methyl methacrylate (MMA) as a methacrylic acid ester monomer, and A mixture of 1.5 parts by mass of methyl acrylate (MA), 0.3 parts by mass of n-octyl mercaptan, and 0.15 parts by mass of a surfactant (“ADEKACOL CS-141E”) was dropped from the dropping funnel over 40 minutes. to form a third layer (layer (II)). After the dropwise addition was completed, the reaction was continued at 80° C. for 1 hour, and after confirming that 99.9% or more of each monomer had been consumed by gas chromatography, the polymerization was terminated.
After the obtained latex was placed in a container equipped with a stirrer and mixed, an aqueous solution of magnesium sulfate was added to salt out and coagulate the latex. The coagulate was washed with water, dehydrated and dried to obtain multilayer structure polymer particles (a-3). Table 1 shows the physical properties of the multilayer structure polymer particles (a-3).

(Block copolymer (b));
Block copolymer (Bb-1): consisting of [methyl methacrylate (MMA) polymer block (bII)]-[n-butyl acrylate (BA)/benzyl acrylate (BzA) copolymer block (bI)], The weight average molecular weight (Mw) is 90,000, the polymer block mass ratio (bII):(bI) is 50:50, and the monomer mass ratio (MMA:BA:BzA) = (50:36). : 14), a diblock copolymer with Mw (b1) = 45,000 and Mw (b2) = 45,000.
Block copolymer (Bb-2): consisting of [methyl methacrylate (MMA) polymer block (bII)] - [n-butyl acrylate (BA)) copolymer block (bI)], weight average molecular weight (Mw) is 120,000, the mass ratio of polymer blocks (bII): (bI) is 50:50, the mass ratio of each monomer (MMA:BA) = (50:50), Mw (b1) = 60 ,000, Mw(b2)=60,000.
Block copolymer (Bb-3): [methyl methacrylate (MMA) polymer block (bII)] - [n-butyl acrylate (BA) polymer block (bI)] - [methyl methacrylate (MMA) polymer block ( bII)], has a weight average molecular weight (Mw) of 670,000,000, and has a polymer block mass ratio (bII):(bI):(bII) of 17.0:50.0:33.0, A triblock copolymer in which the mass ratio of each monomer (MMA:BA) = (50:50), Mw (b1) = 33,500, and Mw (b2) = 33,500.

[Example 1]
78.9 parts by mass of methacrylic resin (A-1), 8.1 parts by mass of multilayer structure polymer particles (Ba-1), and 13.0 parts by mass of block copolymer (Bb-1) The mixture was melt-kneaded with an extruder at a cylinder temperature of 230 to 250°C. After that, the molten resin composition was extruded to obtain a pellet-shaped methacrylic resin composition (R1), which was dried at 80° C. for 24 hours.
Using an injection molding machine (M-100C manufactured by Meiki Seisakusho) with a cylinder temperature of 250 ° C and a mold temperature of 50 ° C, the methacrylic resin composition (R1) is filled at a rate of 50 mm / s into a JIS test piece mold. Moldings of 10 mm x 80 mm x 4 mm and 50 mm x 50 mm x 3 mm were obtained by injection. Table 2 shows the physical property evaluation results.

[Examples 2 to 9]
Methacrylic thermoplastic resin compositions (R2) to (R9) were obtained in the same manner as in Example 1, except that the compositions were changed to those shown in Table 2. In each example, in the same manner as in Example 1, the obtained resin composition was used to obtain a molded article. Table 2 shows the physical property evaluation results in each example.

[Comparative Examples 1 to 7]
Thermoplastic resin compositions (R10) to (R16) were obtained in the same manner as in Example 1, except that the compositions were changed to those shown in Table 2. In each comparative example, a molded article was obtained using the obtained resin composition in the same manner as in Example 1. Table 2 shows the physical property evaluation results in each comparative example.

[Discussion]
The methacrylic resin composition of the present invention containing a specific methacrylic resin (A), specific multilayer structure polymer particles (Ba1), and a specific block copolymer (Bb-1) or (Bb-2) The molded articles obtained in Examples 1 to 9 used had good impact strength while maintaining optical performance and mechanical performance.

On the other hand, a methacrylic resin composition consisting of a methacrylic resin (A) alone or a methacrylic resin (A) and a block copolymer (Bb-2) and containing no multilayer structure polymer particles (a) The molded articles obtained in Comparative Examples 1 and 2 using the were inferior in impact strength as compared with the examples having the same rubber content.

A methacrylic resin composition is used in which the rubber content of one of the multilayer structure polymer particles (a) and block copolymer (b) is extremely high or low relative to the rubber content of the other. The molded articles obtained in Comparative Examples 3 to 5, which had a high rubber content, were inferior in impact strength as compared with the examples having the same rubber content.

The molded articles obtained in Comparative Examples 6 and 7 using the methacrylic resin compositions containing multi-layered structure polymer particles (Ba-2) and (Ba-3) with small volume average particle diameters were compared with the examples. However, the impact strength was poor.

Claims (7)

In a methacrylic resin composition in which a methacrylic resin (A) forms a matrix and a rubber-like elastic body (B) is dispersed, a methacrylic resin that satisfies the following requirements (1) to ( 7 ): system resin composition.
(1) Rubber-like elastomer (B) contains multilayer structure polymer particles (a) and block copolymer (b).
(2) The multi-layer structure polymer particles (a) have at least one rubber component layer (aI) and have a hard resin component layer (aII) on the outermost layer, and the average of the rubber component layers closest to the outermost layer The particle size is in the range of 0.19-0.3 μm.
(3) The methacrylic resin composition contains 3 to 20% by mass of the rubber component layer (aI) of the multilayer structure polymer particles (a).
(4) Block copolymer (b) contains methacrylic polymer block (bII) and acrylic polymer block (bI), and acrylic polymer block (bI) is a rubber component.
(5) The total rubber component content of (aI) and (bI) in the methacrylic resin composition is in the range of 5 to 45% by mass.
(6) The content ratio of (bI) to the total rubber component content of (aI) and (bI) in the methacrylic resin composition is in the range of 25 to 90% by mass.
(7) Weight average molecular weights Mw (bII) and Mw (bI) of methacrylic polymer block (bII) and acrylic polymer block (bI) of block copolymer (b) and weight of methacrylic resin (A) The average molecular weight Mw (A) satisfies the following formulas (Y) and (Z).
0.5≦Mw(A)/Mw(bII)≦2.5 (Y)
5,000≤Mw(bI)≤120,000 (Z) The multilayer structure polymer particles (a) contain 50 to 89.99% by mass of acrylic acid ester monomer units and 44.99 to 10% by mass of other monofunctional monomer units in the rubber component layer (aI). , and at least one rubber component layer (aI) containing a copolymer consisting of 0.01 to 10% by mass of polyfunctional monomer units, and the outermost layer has 50 to 100 methacrylic acid ester monomer units. % by mass and at least one hard resin component layer (aII) composed of 50 to 0 mass% of other monomer units, and the total amount of the rubber component layer (aI) and the total amount of the hard resin component layer (aII) 2. The methacrylic resin composition according to claim 1, wherein the mass ratio (aI/aII) is from 30/70 to 90/10. The acrylic polymer block (bI) of the block copolymer (b) is a copolymer block of 50 to 90% by mass of alkyl acrylate and 50 to 10% by mass of aromatic (meth)acrylate. 3. The methacrylic resin composition according to Item 1 or 2. 4. The methacrylic resin composition according to claim 3, wherein the (meth)acrylic acid aromatic ester is benzyl acrylate. A molded article comprising the methacrylic resin composition according to any one of claims 1 to 4 . The molded article according to claim 5 , which is an injection molded article. A method for producing a film, comprising a step of melt-extruding or solution-casting the methacrylic resin composition according to any one of claims 1 to 4 .