JP2021004325A - Methacrylic resin composition and molding thereof, and method for producing film - Google Patents

Abstract

To provide a methacrylic resin composition which is excellent in impact strength, optical performance and mechanical performance and contains multilayer structure polymer particles.SOLUTION: A methacrylic resin composition in which a methacrylic resin (A) forms a matrix and a rubber-like elastic body (B) is dispersed, and satisfies that 1) a particle size distribution of (B) has multiple peaks, the one peak having the largest average particle size in (B) contains two or more layers of multilayer structure polymer particles (a) containing a rubber component layer (aI) and a hard resin component layer (aII), the other peak having the smallest average particle diameter contains a block copolymer (2) containing a methacrylic polymer block (bII) and an acrylic polymer block (bI), 2) a theoretical distance between surfaces of (aI) satisfies a specific relationship, 3) a rubber component content of the total of (aI) and (bI) in the composition is 5-45 mass%, and 4) a (bI) percentage content to the rubber component content of the total of (aI) and (bI) in the composition is 5-90 mass%.SELECTED DRAWING: None

Description

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

Since methacrylic resin is excellent in optical performance such as transparency and surface gloss, and mechanical performance such as rigidity and scratch resistance, display members such as lighting fixtures and signboards, optical members such as display parts, interior members, building members, etc. It has been used conventionally for various purposes such as electronic and electrical components. However, since methacrylic resin is a brittle material, it is generally difficult to adapt it to applications that require impact strength.

To improve the impact strength of the methacrylic resin, multi-layered polymer particles (so-called core-sell type polymer particles) having a rubber component layer inside and a thermoplastic resin component layer on the outermost layer are added. The method used is preferably used. This method is currently the most widely practiced in industry.

For example, Patent Document 1 knows a method of blending a multilayer structure acrylic rubber produced by an emulsion polymerization method with a methacrylic resin. However, the impact strength improving effect of the methacrylic resin by this method cannot be said to be sufficient, and it is necessary to add a large amount of acrylic rubber in order to satisfy the required impact strength. Adding a large amount of acrylic rubber is not preferable because it impairs the optical performance and mechanical performance of the methacrylic resin.

As a method for improving 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 was added to the multilayer structure polymer particles composed of a copolymer of an acrylic acid ester and a methacrylic acid ester. The 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.

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

Special Publication No. 59-36645 WO2012 / 057079 A JP-A-2002-194167 WO2017 / 188290 A

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 product thereof, and a method for producing a film.

[1]
A methacrylic resin composition in which a methacrylic resin (A) forms a matrix and a rubber-like elastic body (B) is dispersed satisfies the following requirements (1) to (4). Acrylic composition.
(1) The particle size distribution of the rubber-like elastic body (B) dispersed in the composition is multimodal, and among the rubber-like elastic bodies (B), one peak having the largest average particle size is the rubber component. The other peak containing two or more layers of the multilayer structure polymer particles (a) containing the layer (aI) and the hard resin component layer (aII) and having the smallest average particle size is the methacrylic polymer block (bII). Includes a block copolymer (b) containing an acrylic polymer block (bI).
(2) The multilayer structure polymer particles (a) satisfy the following formula (W).
L / de ² ≤ 5.5 (W)
L: Distance between theoretical surfaces of the multilayer structure polymer particle rubber component layer de: Average particle size of the multilayer structure polymer particle rubber component layer However, the theoretical surface distance (L) of the multilayer structure polymer particle rubber component layer is as follows. It is calculated from the calculation formula (X) of.
L = de × ((π / 6φ) ^1/3 -1) (X)
φ: Volume fraction up to the multilayer structure polymer particle rubber component layer (3) The total rubber component content of (aI) and (bI) in the methacrylic resin composition is in the range of 5 to 45% by mass. ..
(4) The ratio of the (bI) content 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 methacrylic resin composition according to [1], wherein the average particle diameter of the multilayer structure polymer particles (a) rubber component layer (aI) is in the range of 0.05 to 0.3 μm.
[3]
The methacrylic resin composition according to [1] or [2], wherein the multilayer structure polymer particles (a) contain 5 to 40% by mass of a rubber component layer (aI).
[4]
The multilayer structure polymer particles (a) include at least one rubber component layer (aI) and at least one hard resin component layer (aII), and the outermost layer of the particles (a) is a hard resin component layer (aII). The rubber component layer (aI) is an acrylic acid ester monomer unit of 50 to 89.99% by mass, another monofunctional monomer unit of 44.99 to 10% by mass, and a polyfunctional monomer unit. The hard resin component layer (aII) contains a copolymer consisting of 0.01 to 10% by mass, and the methacrylic acid ester monomer unit is 40 to 100% by mass and the other monomer unit is 60 to 0% by mass alone. It contains a polymer or copolymer, and is characterized in that the mass ratio (aI / aII) of the total amount of the rubber component layer (aI) and the total amount of the hard resin component layer (bI) is 30/70 to 90/10. The methacrylic resin composition according to any one of [1] to [3].
[5]
The description according to any one of [1] to [4], wherein the acrylic resin block (bI) of the block copolymer (b) is contained in the methacrylic resin composition in an amount of 3 to 10% by mass. A methacrylic resin composition.
[6]
The acrylic polymer block (bI) of the block copolymer (b) is a copolymer block of 50 to 90% by mass of acrylic acid alkyl ester and 50 to 10% by mass of (meth) acrylic acid aromatic ester. 1] The methacrylic resin composition according to any one of [5].
[7]
The methacrylic resin composition according to [6], wherein the (meth) acrylic acid aromatic ester is benzyl acrylic acid.
[8]
Weight average molecular weights of methacrylic polymer block (bII) and acrylic polymer block (bI) of block copolymer (b) Mw (bII), Mw (bI) and methacrylic resin (A) weight average molecular weight Mw The methacrylic resin composition according to any one of [1] to [7], 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)
[9]
A molded product containing the methacrylic resin composition according to any one of [1] to [8].
[10]
The molded product according to [9], which is an injection molded product.
[11]
A method for producing a film, which comprises a step of melt extrusion or solution casting of the methacrylic resin composition according to any one of [1] to [8].

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

"Methacrylic resin composition"
The methacrylic resin composition of the present invention contains a methacrylic resin (A) and a rubber-like elastic body (B), and the rubber-like elastic body (B) is a multilayer structure polymer particle (a) having at least one two or more layers. ) And at least one block copolymer (b).

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

The block copolymer (b) includes 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 the present specification, the total amount of (aI) and (bI) may be described as "rubber component content", but the methacrylic resin composition of the present invention is a rubber other than (aI) and (bI). It may contain an ingredient.

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), and more preferably 30 to 80% by mass of the methacrylic resin (A). It contains 85% by mass and 15 to 70% by mass of the rubbery elastic body (B).

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

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

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

Examples of the monomer other than methyl methacrylate include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, s-butyl acrylate, and t-butyl acrylate. Butyl, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethyl hexyl acrylate, pentadecyl acrylate, dodecyl acrylate; phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, 2-ethyl acrylate Hydroxyethyl, 2-ethoxyethyl acrylate, glycidyl acrylate, allyl acrylate; acrylic acid 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, methacrylic 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; such as ethylene, propylene, 1-butene, isobutylene, 1-octene, etc. Olefins; conjugated diene such as butadiene, isoprene, milsen; aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene; acrylamide, methacrylicamide, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl Examples thereof include 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, one 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, and particularly preferably. It is 50,000 or more and 500,000 or less. If Mw (A) is too small, the impact resistance and toughness of the molded product obtained from the obtained methacrylic resin composition tend to decrease. If Mw (A) is too large, the fluidity of the methacrylic resin composition tends to decrease, and the molding processability tends to decrease.

Ratio of weight average molecular weight Mw (A) and number average molecular weight Mn (A) of methacrylic resin (A), Mw (A) / Mn (A) (hereinafter, ratio of weight average molecular weight to number average molecular weight (weight average molecular weight) / Number average molecular weight) is sometimes referred to as “molecular weight distribution”), preferably 1.03 or more and 2.6 or less, more preferably 1.05 or more and 2.3 or less, and particularly preferably 1.2 or more 2 It is less than or equal to 0.0. 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 molded product obtained from the methacrylic resin composition is lowered, and the molded product tends to be brittle.

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

Further, the molecular weight and the 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 a 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., 37.3N)) and "Parapet GF" (MFR: 15 g / 10 minutes (230 ° C., 37.3N)). 3N)), "Parapet EH" (MFR: 1.3 g / 10 minutes (230 ° C, 37.3N)), "Parapet HRL" (MFR: 2.0 g / 10 minutes (230 ° C, 37.3N)) and Examples include "Parapet G" (MFR: 8.0 g / 10 minutes (230 ° C., 37.3 N)) [both trade names, manufactured by Kuraray Co., Ltd.].

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

Further, the particle size distribution of the rubber-like elastic body (B) is multimodal, and among the rubber-like elastic bodies (B), one peak having the largest average particle size is a multilayer structure polymer particle (a) having two or more layers. ), And the other peak having the smallest average particle size contains a block copolymer (b) containing a methacrylic polymer block (bII) and an acrylic polymer block (bI).

Since the rubber-like elastic body (B) contains at least one type of multilayer structure polymer particles (a) and at least one type of block copolymer (b), it is bimodal, trimodal, quaternary or the like. It may be the above. Since the average particle size of the multilayer structure polymer particles (a) is larger than the average particle size of the block copolymer (b), the peak having the largest average particle size becomes the multilayer structure polymer particles (a), and the average particles. The one peak with the smallest diameter is the block copolymer (b).

(Multilayer structure polymer particles (a))
The multilayer structure polymer particles (a) have at least one rubber component layer (aI) inside (hereinafter, may be simply abbreviated as “(aI)”) and at least one hard outermost. It is a particle having a core-shell structure having a resin component (aII) (hereinafter, may be simply abbreviated as “(aII)”) and the outermost part being a hard resin component (aII). The core of the multilayer structure polymer particles (a) is regarded as a “layer”. The number of layers of the multilayer structure polymer particles (a) may be two or more, and may be three, four, or more. The layer structure is a two-layer structure of (aI)-(aII) from the center; (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 can be mentioned. 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 product of the resin composition of the present invention may have insufficient impact strength. If the ratio of (aI) exceeds the above range, it may be difficult to form a particle structure, and the melt fluidity may be lowered, which may make it difficult to knead with other components and to mold the resin composition of the present invention. 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 mass ratio is calculated based on the total amount thereof, and the resin composition of the present invention has two or more hard resin component layers (aII). In the case, the mass ratio is calculated based on the total amount.

(AI) is an acrylic acid ester monomer unit 50 to 89.99% by mass, another monofunctional monomer unit 44.99 to 10% by mass, and a polyfunctional monomer unit 0.01 to 10%. It is preferable to contain a copolymer containing% by mass. The content of the acrylic 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 content of the unit 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) becomes insufficient, and the impact strength of the molded product of the resin composition of the present invention is insufficient. If it exceeds 89.99% by mass, it may be difficult to form a particle structure. If the content of the other monofunctional monomer unit 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 be insufficient. 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 product of the methacrylic resin composition of the present invention becomes high. It may be insufficient, and if it is less than 0.01% by mass, it may be difficult to form a particle structure.

Hereinafter, the raw material monomer of the rubber component layer (aI) will be described.

Examples of the acrylic acid ester 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, and hexyl acrylate. Esters of acrylic acids such as octyl acrylates, 2-ethylhexyl acrylates, dodecyl acrylates, and octadecyl acrylates with saturated aliphatic alcohols (preferably saturated aliphatic alcohols C1 to C18); acrylic acids such as cyclohexyl acrylate and C5 or C6. Examples thereof include esters with alicyclic alcohols; esters with acrylic acids such as phenyl acrylate and phenols; esters with acrylic acids such as benzyl acrylate and aromatic alcohols. Acrylic ester can be used alone or in combination of two or more.

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, etc. Esters of methacrylic acid such as dodecyl methacrylate, myristyl methacrylate, palmityl methacrylate, stearyl methacrylate, and behenyl methacrylate with saturated aliphatic alcohols (preferably saturated aliphatic alcohols C1 to C22); methacrylic acid such as cyclohexyl methacrylate and C5 or C6 ester with alicyclic alcohol; ester with methacrylic acid such as phenyl methacrylate and phenols, ester with methacrylic acid such as benzyl methacrylate and ester with aromatic alcohol; styrene (St), α-methyl Such as styrene, 1-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4- (phenylbutyl) styrene, and halogenated styrene. Aromatic vinyl-based monomers; examples thereof include vinyl cyanide-based monomers such as acrylonitrile and methacrylonitrile. Of these, styrene is preferable. Other monofunctional monomers may be used alone or in combination of two or more.

A polyfunctional monomer is a monomer having two or more carbon-carbon double bonds in the molecule. Examples of the polyfunctional monomer include an ester of an unsaturated monocarboxylic acid such as acrylic acid, methacrylic acid, and cinnamic acid and an unsaturated alcohol such as allyl alcohol and β-metharyl alcohol; the unsaturated monocarboxylic acid described above. Diesters of 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, and the unsaturated alcohols mentioned above. Specifically, allyl acrylate, methallyl acrylate, allyl methacrylate (ARMA), methallyl methacrylate, allyl silicate, methallyl cinnate, diallyl maleate, diallyl phthalate, diallyl terephthalate, diallyl isophthalate, divinylbenzene, ethylene Examples thereof include glycol di (meth) acrylate, butanediol di (meth) acrylate, and hexanediol di (meth) acrylate. Of these, allyl methacrylate (ALMA) is preferable. As the polyfunctional monomer, one kind or two or more kinds can be used.

The layer (aII) preferably contains a copolymer composed of 50 to 100% by mass of the methacrylic ester monomer unit and 50 to 0% by mass of other monomer units. The content of the methacrylic acid ester monomer unit is more preferably 60 to 99% by mass, further preferably 80 to 99% by mass, and the content of the other monomer unit is more preferably 50 to 1% by mass, further preferably. Is 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 multilayer structure polymer particles (a) may be insufficient.

Hereinafter, the raw material monomer of the hard resin component layer (aII) will be described.

Examples of methacrylic acid esters 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, and dodecyl methacrylate. , Myristyl methacrylate, palmityl methacrylate, stearyl methacrylate, behenyl methacrylate, octadecyl methacrylate, phenyl methacrylate, benzyl methacrylate and the like. Of these, 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, and hexyl. Acrylate such as acrylate, octyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, and octadecyl acrylate and ester of saturated aliphatic alcohol (preferably saturated aliphatic alcohol of C1 to C18); acrylic acid such as cyclohexyl acrylate and C5 or Acrylate of C6 with acryloal alcohol; styrene (St), α-methylstyrene, 1-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4 -Aromatic vinyl-based monomers such as benzylstyrene, 4- (phenylbutyl) styrene, and styrene halide; vinyl cyanide-based monomers such as acrylonitrile and methacrylonitrile; maleimide, N-methylmaleimide, N- Maleimide-based monomers such as ethyl maleimide, N-propyl maleimide, N-isopropyl maleimide, N-cyclohexyl maleimide, N-phenyl maleimide, N- (p-bromophenyl) maleimide, and N- (chlorophenyl) maleimide; layer ( Examples thereof include the polyfunctional monomer exemplified in aI). Of these, acrylic acid alkyl esters such as methyl acrylate (MA), ethyl acrylate, and n-butyl acrylate (BA) are preferable.

In the multilayer structure polymer particles (a), the weight average molecular weight (Mw) of the constituent copolymer of the outermost layer (aII) measured by the GPC method is in the range of 20,000 to 100,000. It is preferably in the range of 30,000 to 90,000, more preferably in the range of 40,000 to 80,000. If the Mw is less than 20,000, the rubber elasticity of the multilayer structure polymer particles (a) may be insufficient, making it difficult to mold the molded product of the resin composition of the present invention. If Mw exceeds 100,000, the impact strength of the molded product may decrease.

The average particle size (de) of the multilayer structure polymer particles (a) rubber component layer is preferably in the range of 0.05 to 0.3 μm. In the resin composition, the multilayer structure polymer particles (a) provide a field for stress concentration. If the average particle size is less than 0.05 μm, the stress concentration on the multilayer structure polymer particles (a) becomes insufficient, and the impact strength of the molded product may decrease. If it exceeds 0.3 μm, voids are likely to be generated inside the multilayer structure polymer particles (a). Further, when the rubber content in the resin composition is constant, the number of particles decreases when the particle size becomes larger than a certain level, so that 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. Voids here are fractures that occur only inside the particles, and since the amount of energy absorbed 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 size is preferably 0.06 to 0.25 μm, more preferably 0.07 to 0.23 μm.

The average particle size (de) of the multilayer structure polymer particles (a) rubber component layer 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. The method using an electron microscope is performed in the rubber component layer (aII) of the stained multilayer structure polymer particles (a) observed by a transmission electron microscope when the resin composition of the present invention is electronically dyed with ruthenium tetroxide. It is the average value of the major axis diameter and the minor axis diameter of what constitutes the outermost part. In the method by the light scattering method, when the multilayer structure polymer particles are polymerized, the latex polymerized up to the rubber component layer is sampled and measured using a laser diffraction / scattering type particle size distribution measuring device LA-950V2 manufactured by Horiba Seisakusho Co., Ltd. it can.

The theoretical surface-to-surface distance (L) of the multilayer structure polymer particles (a) rubber component layer is described in the following formula (S.Wu; Polymer, 26, 1855, (1985)). It has a relationship expressed by the theoretical formula of X).
L = de × ((π / 6φ) ^1/3 -1) (X)
L: Theoretical surface-to-surface distance of the multilayer structure polymer particle rubber component layer (aI) de: Average particle diameter of the multilayer structure polymer particle rubber component layer (aI) φ: Up to the multilayer structure polymer particle rubber component layer (aI) Volume fraction

In the resin composition of the present invention, the distance between the theoretical surfaces (L) of the multilayer structure polymer particles (a) rubber component layer and the average particle diameter (de) of the multilayer structure polymer particle rubber component layer are set.
L / de ² ≤ 5.5 (W)
[L: Theoretical surface-to-surface distance of the multilayer structure polymer particle rubber component layer (aI) de: Average particle size of the multilayer structure polymer particle rubber component layer (aI) However, of the multilayer structure polymer particle rubber component layer (aI) The theoretical surface-to-surface distance (L) is calculated from the above formula (X). ]
Satisfy the relationship. It is preferably L / de ² ≤ 5.4, and more preferably L / de ² ≤ 5.3. By satisfying the relationship of L / de ² ≤ 5.5, the stress state of the multilayer structure polymer particles (a) rubber component interlayer matrix region changes, and the block copolymer (b) exists in the matrix region. As a result, shear yield is promoted and impact strength is improved.

In one preferred embodiment of the present invention, the method for producing the multilayer structure polymer particles (a) according to the present invention is a multilayer structure polymer having a rubber component layer (aI) / hard resin component layer (aII) as described above. The method is not particularly limited as long as the particles (a) can be obtained. A preferred method for producing the multilayer structure polymer particles (a) having a three-layer structure (core-intermediate layer-outermost layer) according to the present invention is to emulsion-polymerize a monomer for obtaining a polymer constituting the center core. Seed particles (i) are obtained, and in the presence of seed particles (i), a monomer for obtaining a polymer constituting an intermediate layer is seed-emulsified and polymerized to obtain seed particles (ii). This includes a step of seed emulsion polymerization of a monomer for obtaining a polymer constituting the outermost layer in the presence of the above to obtain seed particles (iii). The multi-layered polymer particles (a) having a two-layer structure or a four-layer or higher layer structure may be one of ordinary skill in the art with reference to the above description of the method for producing the three-layer structure multi-layer structure polymer particles (a). Can be easily manufactured. Since the emulsification polymerization method or the seed emulsification polymerization method is a technique well known in the art as a method for obtaining general multilayer structure polymer particles, detailed explanations can be referred to in other documents. In the above preferred example, the seed particles (i) are single-layer 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. The particles are composed of two layers (aI, intermediate layer), and the seed particles (iii) are hard resin component layer (aII, core) + rubber component layer (aI, intermediate layer) + hard resin component layer (aII, most). It is a particle having a three-layer structure (outer layer).

In the polymerization reaction step, the polymerization conditions are adjusted so that the Mw of the constituent copolymer of the hard resin component layer (aII) constituting at least the outermost layer is 20,000 to 100,000. The polymerization conditions are mainly adjusted by the amount of a molecular weight modifier such as alkyl mercaptan. Polymerization in the total polymerization reaction step so that the average particle diameter of the finally obtained multilayer structure polymer particles (a) up to the outermost hard resin component layer (aII) is in the range of 0.07 to 0.35 μm. Adjust the conditions.

The average particle size of the multilayer structure polymer particles (a) up to the outermost hard resin component layer (aII) is determined by sampling the polymerized latex during the multilayer structure polymer particle polymerization and laser diffraction / manufactured by Horiba Seisakusho Co., Ltd. It can be measured by a light scattering method using a scattering type particle size distribution measuring device LA-950V2.

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

From the viewpoint of compatibility, the block copolymer (b) includes 10 to 80% by mass of the polymer block (bII) having a methacrylic acid ester monomer unit and a weight mainly having an acrylic acid ester monomer unit. Block copolymers containing 90 to 20% by mass of the coalesced block (bI) (provided that the total amount of the polymer block (bII) and the polymer block (bI) is 100% by mass) are preferable. In the block copolymer (b), the content of the polymer block (bII) is more preferably 20 to 70% by mass, further preferably 30 to 60% by mass, and the content of the polymer block (bI). Is more preferably 80 to 30% by mass, still 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 plurality of polymer blocks (bII) may be the same or non-identical. Similarly, the number of polymer blocks (bI) in a 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 plurality of polymer blocks (bI) may be the same or non-identical.

The polymer block (bII) mainly contains a methacrylic acid ester monomer unit. The content of the methacrylic ester monomer unit 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. It may be composed of only the methacrylic ester monomer unit.

Hereinafter, the raw material monomer of the methacrylic polymer block (bII) will be described.

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, and 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. Nyl methacrylate and the like are preferable, and methyl methacrylate (MMA) is particularly preferable. One kind or two or more kinds of 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, still more preferably 12,000, and particularly preferably 15,000. It is preferably 20,000, with an upper limit of preferably 150,000, more preferably 120,000, and particularly preferably 100,000. When the block copolymer (b) has a plurality of polymer blocks (bII), the weight average molecular weight (Mw (bII)) is the total amount of Mw of the plurality of polymer blocks (bII).

In one preferred embodiment of the present invention, the weight average molecular weights of the methacrylic polymer block (bII) of the block copolymer (b) Mw (bII), Mw (bI) and the methacrylic resin (A). Mw (A) satisfies the following formula (Y).
0.5 ≤ Mw (A) / Mw (bII) ≤ 2.5 (Y)

The ratio of the weight average molecular weight Mw (A) of the methacrylic resin (A) to Mw (bII), that is, Mw (A) / Mw (bII) is 0.5 or more and 2.5 or less, preferably 0.6 or more. It is 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 product made from the resin composition tends to decrease. On the other hand, if Mw (A) / Mw (bII) is too large, the surface smoothness and transparency of the plate-shaped molded product prepared from the resin composition tend to deteriorate. When Mw (A) / Mw (bII) is in the above range, the dispersed particle size of the block copolymer (b) in the methacrylic resin (A) becomes small, so that the transparency is excellent.

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

In one preferred embodiment of the invention, the acrylic polymer block (bI) primarily comprises an acrylic ester monomer unit. The content of the acrylic acid ester monomer unit in the acrylic polymer block (bI) is preferably 60% by mass or more, more preferably 65% by mass or more, still more preferably 70% by mass or more, and particularly preferably 90% by mass. % Or more.

Hereinafter, the raw material monomer of the acrylic polymer block (bI) will be described.

Acrylate 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. 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. And so on. Acrylic ester can be used alone or in combination of two or more.

In another preferred embodiment of the present invention, from the viewpoint of transparency of the resin composition of the present invention, the acrylic polymer block (bI) includes an acrylic acid alkyl ester monomer unit and (meth) acrylic acid. A polymer block (bI-p) containing an aromatic hydrocarbon ester monomer unit is preferable. 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, and (meth) acrylic acid aromatic carbonation. The content of the hydrogen ester monomer unit 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 weight average molecular weight Mw (bI) of the acrylic polymer block (bI) has a lower limit of preferably 5,000, more preferably 15,000, still more preferably 20,000, particularly preferably 30,000, and most preferably. It is 40,000, with an upper limit of preferably 120,000, more preferably 110,000, and particularly preferably 100,000. If Mw (bI) is too small, the impact resistance of the molded product of the thermoplastic resin composition of the present invention may decrease. On the other hand, if Mw (bI) is excessive, the surface smoothness of the molded product of the resin composition of the present invention may decrease. When the block copolymer (b) has a plurality of polymer blocks (bI), the weight average molecular weight Mw (bI) is the total amount of Mw of the plurality of polymer blocks (bI).

The content of the acrylic polymer block (bI) in the block copolymer (b) is the transparency, flexibility, flexibility, bending resistance, and impact resistance of the molded article of the methacrylic resin composition of the present invention. From the viewpoint of property, 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 a plurality of polymer blocks (bI), the content of the polymer block (bI) is the total content of the plurality of acrylic polymer blocks (bI).

The average size of the acrylic polymer block (bI) domain of the block copolymer (b) can be measured as follows. The major axis diameter and shortness of the acrylic polymer block (b1) of the stained block copolymer (b) observed with a transmission electron microscope when the resin composition of the present invention is electron-stained with ruthenium tetraoxide. The average value with the shaft diameter is used as the domain size, and 10 domain sizes appropriately selected from each of the acrylic polymer blocks (b1) stained in the transmission electron microscope observation image are measured, and the average value is used as the domain size. The average size of.

The average size of the acrylic polymer block (bI) domain of the block copolymer (b) is preferably equal to or less than the average particle diameter (de) of the multilayer structure polymer particles (a) and the rubber component layer (aI). The ratio of the acrylic polymer block (b1) to the multilayer structure polymer particles (a) (average size of acrylic polymer block (bI) domain / average particle size of rubber component layer (aI)) is 0.06 to It is more preferably in the range of 1.0. When the domain average size of the acrylic polymer block (bI) is within the above range, the methacrylic resin composition of the present invention is excellent in impact strength.

The bond form 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 (bI) is connected to one end of the polymer block (bII); the polymer block. A triblock copolymer having a (bI)-(bII)-(bI) structure in which one end of the polymer block (bI) is connected to each of both ends of (bII); both ends of the polymer block (bI). Examples thereof 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 other.

Of these, diblock copolymers and triblock copolymers are preferable, and diblock copolymers having a (bII)-(bI) structure and triblock copolymers having a (bII)-(bI)-(bII) structure are preferable. More preferred.

If necessary, the block copolymer (b) may have a functional group such as a hydroxyl group, a carboxyl group, an acid anhydride group, and an amino group in the molecular chain and / or at the terminal 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 50,000 to 200,000. When Mw (b) is within the above range, the amount of unmelted material at the time of melt-kneading of the raw material in the production of the resin composition which causes the generation of lumps in the molded product can be made extremely small.

The block copolymer (b) preferably has a ratio (Mw (b) / Mn (b)) of a weight average molecular weight (Mw (b)) to a number average molecular weight (Mn (b)) of 1.0 to 2. It is 0.0, more preferably 1.0 to 1.6. When Mw (b) / Mn (b) is within the above range, the amount of unmelted material at the time of melt-kneading of the raw material in the production of the resin composition, which causes the generation of lumps in the molded product, should be extremely small. Can be done.

The method for producing the block copolymer (b) is not particularly limited, and a method of living-polymerizing each polymer block is common. As the living polymerization method, an organic alkali metal compound is used as a polymerization initiator to perform anionic polymerization in the presence of an alkali metal or an alkali earth metal salt or other mineral salt, and an organic alkali metal compound is used as a polymerization initiator to form an organic aluminum. Examples thereof include a method of anion polymerization in the presence of a compound, a method of polymerizing 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-halogen ester compound as a polymerization initiator. In addition, a method of polymerizing using a multivalent radical polymerization initiator or a multivalent radical chain transfer agent can also be mentioned. Among them, since 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, an organoalkali metal compound is used as a polymerization initiator for the organoaluminum compound. A method of anionic polymerization in the presence is particularly preferred.

The refractive index of the block copolymer (b) is not particularly limited, and is preferably 1.485 to 1.495, more preferably 1.487 to 1.493. When the refractive index is within the above range, the transparency of the thermoplastic resin composition of the present invention becomes high. In the present specification, the "refractive index" means a value measured at a wavelength of 587.6 nm (D line).

A resin composition having excellent transparency and impact strength by adding the multilayer structure polymer particles (a) according to the present invention to the mixing step with the methacrylic resin (A) and the block copolymer (b) and kneading them. Can be obtained. There are the following four methods for mixing the methacrylic resin (A), the multilayer structure polymer particles (a), and the block copolymer (b), and any of them may be selected.
(i) A two-step 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 with the mixture of (A) + (a);
(ii) A two-step mixing method in which the methacrylic resin (A) and the block copolymer (b) are first mixed, and the multilayer structure polymer particles (a) are mixed with the mixture of (A) + (b);
(iii) A two-step mixing method in which the multilayer structure polymer particles (a) and the block copolymer (b) are first mixed, and then the methacrylic resin (A) is mixed with 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, a known method such as a batch type kneader such as a Banbury mixer, a pressure kneader, or a lavender plast graph, or a continuous kneader such as a single-screw, twin-screw, or multi-screw extruder is used. It can be carried out. Alternatively, a method may be used in which a high-concentration master pellet is once prepared by the above method, and then the diluted master pellet is melt-kneaded. From the viewpoint of productivity, the single-screw method or the double-screw method is preferable. In particular, a single-screw extruder is preferable because the shear energy given to the resin composition is small.

(Rubber content)
In the methacrylic resin composition of the present invention, the total rubber content 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 It is in the range of 5 to 45% by mass, preferably in the range of 6 to 40% by mass, and more preferably 7 to 30% by mass. If the total rubber content is less than 5% by mass, the impact strength deteriorates, and if it exceeds 45% by mass, the rigidity deteriorates.

(BI rubber ratio)
In the methacrylic resin composition of the present invention, the acrylic polymer block (bI) content ratio to the total rubber content of (aI) and (bI) is in the range of 5 to 90% by mass, and is 10 to 85% by mass. The range is preferably in the range of%, and more preferably in the range of 15 to 80% by mass.

When the acrylic polymer block (bI) content ratio 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, and the impact strength is excellent. ..

(Optional ingredient)
The thermoplastic resin composition of the present invention may contain, if necessary, other polymers in addition to the methacrylic resin (A) and the rubber elastic body (B), as long as the effects of the present invention are not impaired. Good. Other polymers include olefin resins such as polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, and polynorbornene; ethylene-based 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, Amid resins such as nylon 66 and polyamide elastomers; polyphenylene sulfide, polyether ether ketone, 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 resins; thermocurable resins such as phenolic resins, melamine resins, silicone resins, and epoxy resins; polyurethanes; modified polyphenylene ethers; silicones. Modified resins; acrylic rubbers, silicone rubbers; styrene-based thermoplastic polymers such as SEPS, SEBS, and SIS; olefin-based rubbers such as IR, EPR, and EPDM. Other polymers may be used alone or in combination of two or more.

The methacrylic resin composition of the present invention may contain various additives, if necessary. Additives include antioxidants, heat deterioration inhibitors, UV absorbers, light stabilizers, lubricants, mold release agents, polymer processing aids, antistatic agents, flame retardants, dyes / pigments, light diffusers, and luster. Examples thereof include an eraser, an anti-glue agent, an impact resistance modifier, and a phosphor. The content of these additives can be appropriately set as long as the effects of the present invention are not impaired. For example, the content of the antioxidant is 0.01 to 1 part by mass with respect to 100 parts by mass of the thermoplastic resin composition. 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. It is preferable that the amount is 0.01 to 3 parts by mass and the amount of the anti-adhesion agent is 0.001 to 1 part by mass. Other additives can also be added in the range of 0.01 to 3 parts by mass.

The antioxidant is effective in preventing oxidative deterioration of the resin by itself in the presence of oxygen. For example, phosphorus-based antioxidants, phenol-based antioxidants, sulfur-based antioxidants, amine-based antioxidants, and the like can be mentioned. Among them, phosphorus-based antioxidants and phenol-based antioxidants are preferable from the viewpoint of the effect of preventing deterioration of optical properties due to coloring, and the phenol-based antioxidants are used alone or the phosphorus-based antioxidants and phenol-based antioxidants are used. The combined use is more preferable. When a phosphorus-based antioxidant and a phenol-based antioxidant are used in combination, it is preferable to use the phosphorus-based antioxidant / phenol-based antioxidant in a mass ratio of 0.2 / 1 to 2/1. It is more preferable to use it at 5/1 to 1/1.

As phosphorus-based antioxidants, 2,2-methylenebis (4,6-di-t-butylphenyl) octylphosphite ("ADEKA STAB HP-10" manufactured by ADEKA Corporation), 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 Corporation) and the like are preferable.

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

As the sulfur-based antioxidant, dilauryl 3,3'-thiodipropionate, distearyl 3,3'-thiodipropionate, pentaerythritol tetrakis (3-laurylthiopropionate) and the like are preferable.

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

As the thermal deterioration inhibitor, the thermal deterioration of the resin can be prevented by supplementing the polymer radicals generated when exposed to a high temperature under substantially oxygen-free conditions. Examples of the heat deterioration inhibitor include 2-t-butyl-6- (3'-t-butyl-5'-methyl-hydroxybenzyl) -4-methylphenyl acrylate ("Smilizer GM" manufactured by Sumitomo Chemical Co., Ltd.) and 2,4-di-t-amyl-6- (3', 5'-di-t-amyl-2'-hydroxy-α-methylbenzyl) phenylacrylate ("Sumilyzer GS" manufactured by Sumitomo Chemical Co., Ltd.), etc. preferable.

The ultraviolet absorber is a compound that has an ultraviolet absorbing ability and is said to have a function of mainly converting light energy into heat energy. Examples of the ultraviolet absorber include benzophenones, benzotriazoles, triazines, benzoates, salicylates, cyanoacrylates, oxalic acid anilides, malonic acid esters, and formamidines. Of these, benzotriazoles and triazines are preferable. One kind or two or more kinds of ultraviolet absorbers can be used.

Benzotriazoles are highly effective in suppressing deterioration of optical properties such as coloring due to exposure to ultraviolet rays, and are therefore suitable for applying the thermoplastic resin composition of the present invention to optical applications. Examples of benzotriazoles include 4-methyl-2- (2H-benzotriazole-2-yl) phenol (“trade name JF-77” manufactured by Johoku Chemical Industry Co., Ltd.) and 2- (2H-benzotriazole-2-yl). ) -4- (1,1,3,3-Tetramethylbutyl) phenol ("trade name TINUVIN329" manufactured by BASF Japan Ltd.), 2- (2H-benzotriazole-2-yl) -4,6-bis ( 1-Methyl-1-phenylethyl) phenol (“TINUVIN234” manufactured by BASF Japan Ltd.), and 2,2′-methylenebis [6- (2H-benzotriazole-2-yl) -4-t-octylphenol] (“Adecastab LA-31” manufactured by ADEKA Co., Ltd.) and the like are preferable.

Further, when it is desired to efficiently absorb a wavelength in the vicinity of 380 nm, a triazine-type ultraviolet absorber is preferably used. Examples of such an ultraviolet absorber include 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine ("Adecastab LA-F70" manufactured by ADEKA Co., Ltd.). ”), And its analogs, hydroxyphenyltriazine-based ultraviolet absorbers (“TINUVIN 477” and “TINUVIN 460” manufactured by BASF Japan Ltd.) and the like.

A light stabilizer is a compound that is said to have a function of capturing radicals mainly generated by oxidation by light. Suitable light stabilizers include hindered amines such as compounds having a 2,2,6,6-1 tetraalkylpiperidine skeleton. For example, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate (“ADEKA STAB LA-77Y” manufactured by ADEKA Corporation) and the like can be mentioned.

Lubricants are compounds that are said to have the effect of improving mold releasability, processability, etc. by adjusting the slip between the resin and the metal surface and preventing adhesion or adhesion. For example, higher alcohols, hydrocarbons, fatty acids, fatty acid metal salts, aliphatic amides, fatty acid esters and the like can be mentioned. Among them, an aliphatic monohydric alcohol having 12 to 18 carbon atoms and an aliphatic amide are preferable, and an aliphatic amide is more preferable, from the viewpoint of compatibility with the thermoplastic resin composition of the present invention. Aliphatic amides are classified into saturated aliphatic amides and unsaturated aliphatic amides, and unsaturated aliphatic amides are more preferable because a slip effect due to anti-adhesion is expected. As unsaturated aliphatic amides, N, N'-ethylenebisoleic acid amide ("Slipax O" manufactured by Nihon Kasei Corporation) and N, N'-diorail adipic acid amide ("Slipax ZOA" manufactured by Nihon Kasei Corporation) ") And the like.

Examples of the release agent include higher alcohols such as cetyl alcohol and stearyl alcohol; and 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 a release agent. When the higher alcohols and the glycerin fatty acid monoester are used in combination, the ratio is not particularly limited, but the amount of the higher alcohols used: the amount of the glycerin fatty acid monoester used is 2.5: 1 to 3 by mass ratio. 5: 1 is preferable, and 2.8: 1-3.2: 1 is more preferable.

The 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 a polymer particle having a particle size of 0.05 to 0.5 μm, which can be usually produced by an emulsion polymerization method.

Antistatic agents include sodium heptyl sulfonate, sodium octyl sulfonate, sodium nonyl sulfonate, sodium decyl sulfonate, sodium dodecyl sulfonate, sodium cetyl sulfonate, sodium octadecyl sulfonate, sodium diheptyl sulfonate, heptyl sulfonic acid. Potassium, 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, nonyl sulfonate Examples thereof include alkyl sulfonates such as lithium silicate, lithium decyl sulfonate, lithium dodecyl sulfonate, lithium cetyl sulfonate, lithium octadecyl sulfonate, and lithium diheptyl sulfonate.

Examples of the flame retardant include metal hydrates having a hydroxyl group or crystalline water such as magnesium hydroxide, aluminum hydroxide, hydrated aluminum silicate, hydrated magnesium silicate, and hydrotalcite, and phosphoric acid such as polyphosphate amine and phosphoric acid ester. Examples include compounds and silicon compounds, including trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, tricyclohexyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, and dimethyl ethyl. Phosphate-based flame retardants such as phosphate, methyldibutyl phosphate, ethyldipropyl phosphate, and hydroxyphenyldiphenyl phosphate are preferred.

Dyes / pigments include red organic pigments such as parared, fire red, pyrazolone red, thioindico red, and perylene red, blue organic pigments such as cyanine blue and indanslen blue, and green organic pigments such as cyanine green and naphthol green. Pigments are mentioned, and one or more of these can be used.

Examples of the light diffusing agent and the matting agent include glass fine 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.

Examples of the anti-sticking agent 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 powders; polyorganosiloxanes such as dimethylpolysiloxane; amide resins such as octadecylamine, alkyl phosphate, fatty acid esters, and ethylenebisstearylamide. Examples thereof include powder, fluororesin powder such as ethylene tetrafluoride resin, molybdenum disulfide powder, silicone resin powder, silicone rubber powder, and silica.

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

Examples of the phosphor include a fluorescent pigment, a fluorescent dye, a fluorescent white dye, a fluorescent whitening agent, and a fluorescent bleaching agent.

When the methacrylic resin composition of the present invention contains another polymer and / or an additive, the methacrylic resin (A) and / or the rubber-like elastic material (B) (multilayer polymer particles (a) and / Alternatively, it may be added at the time of polymerization of the block copolymer (b)), or a methacrylic resin (A) and / or a rubber-like elastic body (B) (multilayer structure polymer particles (a) and / or block common weight. It may be added at the time of mixing with the coalescence (b), or may be added at the time of mixing with the methacrylic resin (A) and / or the rubbery elastic body (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 by using a molding processing method or a molding processing apparatus generally used for a thermoplastic polymer. For example, a molded product can be manufactured by a molding process method such as injection molding, extrusion molding, compression molding, blow molding, calendar molding, vacuum molding, etc., which undergoes heat melting, a solution casting method, or the like.

The methacrylic resin composition of the present invention is also useful as a film, and is satisfactorily processed by, for example, an ordinary melt extrusion method such as an inflation method, a T-die extrusion method, a calendar method, or a solution casting method. To. Further, if necessary, a film having better surface properties can be obtained by simultaneously contacting both sides of the film with a roll or a metal belt, particularly by simultaneously contacting 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. Further, depending on the purpose, it is possible to modify the film by laminating molding of the film or biaxial stretching.

The film obtained from the methacrylic resin composition of the present invention can be used by laminating it on a metal, plastic or the like. Examples of the laminating method include wet laminating, dry laminating, extraction laminating, hot melt laminating, and the like, 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 and dried and bonded.

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

The methacrylic thermoplastic resin composition of the present invention and a molded product containing the same can be used as a member for various purposes. Specific applications include, for example, signboard parts such as advertising towers, stand signs, sleeve signs, column signboards, roof signs, and marking films; display parts such as showcases, dividers, and store displays; fluorescent lamp covers, mood lighting. Lighting parts such as covers, lamp shades, light ceilings, light walls, chandeliers; Interior parts such as furniture, pendants, mirrors; Doors, dome, safety window glass, partitions, staircase wainscots, balcony wainscots, roofs of leisure buildings, etc. Building parts; aircraft windshields, pilot visors, motorcycles, motor boat windshields, bus shading plates, automobile side visors, rear visors, head wings, headlight covers, sun roofs, glazing, automobile interior parts, bumpers and other automobile exterior parts. Transport equipment related parts such as; nameplates for audiovisual images, stereo covers, TV protective masks, vending machines, mobile phones, personal computers and other electronic equipment parts; incubators, roentgen parts and other medical equipment parts; machine covers, instrument covers, etc. Equipment-related parts such as experimental equipment, rulers, dials, observation windows; optical parts such as liquid crystal protective plates, light guide plates, light guide films, frennel lenses, lenticular lenses, front plates of various displays, diffusers, etc .; road signs, Traffic-related parts such as information boards, curved mirrors, soundproof walls; other greenhouses, large water tanks, box water tanks, bathroom parts, clock panels, bathtubs, sanitary, desk mats, game parts, toys, face protection masks during welding, Examples include backsheets for solar cells, front seats for flexible solar cells; surface materials used for personal computers, mobile phones, furniture, vending machines, bathroom members, and the like.

On the other hand, the laminated laminated products of the film obtained from the methacrylic resin composition of the present invention include automobile interior / exterior materials, daily miscellaneous goods, wallpaper, coating alternative applications, housings for furniture and electrical equipment, and OA equipment such as facsimiles. It can be used for housings, flooring materials, electrical or electronic equipment parts, bathroom equipment, etc.

As described above, the methacrylic resin composition of the present invention contains the methacrylic resin (A) and the 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 multilayer structure polymer particles (a) and the block copolymer (a) are contained in the methacrylic resin (A) matrix. The methacrylic resin composition of the present invention has an impact because b) works excellently synergistically by taking a specific dispersed state and the impact strength of the methacrylic resin can be effectively increased with a small rubber content. It is possible to provide a molded product and a film having excellent strength, optical performance and mechanical performance.

The methacrylic resin composition of the present invention has good impact strength when the multilayer structure polymer particles (a) and the block copolymer (b) in the methacrylic resin (A) matrix take a specific dispersed state. Therefore, in order to realize such a dispersed state, it can be suitably manufactured by injection molding, melt extrusion, solution casting, or the like.

Hereinafter, production examples and examples according to the present invention, and comparative examples will be described.

[Evaluation items and evaluation methods]
The evaluation items and evaluation methods in the 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 the molecular weight distribution (Mw / Mn) of the resin were determined by the GPC method (gas chromatography method). Tetrahydrofuran was used as the eluent. As a column, two TSKgel SuperMultipore HZM-M manufactured by Tosoh Corporation and a SuperHZ4000 connected in series were used. As the 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., the eluent flow rate was 0.35 ml / min, 20 μl of the sample solution was injected into the apparatus, and the chromatogram was measured. Ten standard polystyrenes having a molecular weight in the range of 400 to 5,000,000 were measured by GPC, and a calibration curve showing the relationship between the retention time and the molecular weight was prepared. The Mw and Mw / Mn of the resin to be measured were determined based on this calibration curve.

Regarding the measurement of the multilayer structure polymer particles (a), after immersing the dried multilayer structure polymer particles in acetone for 24 hours, the acetone solution is centrifuged to obtain an acetone insoluble component and an acetone soluble component. Mw was measured for the separated and solidified acetone-soluble component (the outermost hard resin component layer (aII)).

Further, the weight average molecular weights Mw (bI) and Mw (bII) of each block 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 obtained by polymerizing the acrylic polymer block (rubber component, bI) was sampled, Mw was measured, and Mw (bII) was subtracted to determine Mw (bI). Mw was measured by the same method in the case of further polymerizing a methacrylic polymer or an acrylic polymer block, 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 polymer particles was determined by a light scattering method using a laser diffraction / scattering type particle size distribution measuring device LA-950V2 manufactured by Horiba Seisakusho Co., Ltd. For the volume average particle size (de) up to the rubber component layer (aI), the latex after the rubber component layer polymerization was sampled and the volume average particle size was measured. For the average particle size up to the outermost layer, the latex after the outermost layer polymerization was sampled and the volume average particle size was measured.

(Copolymerization composition)
The analysis was performed under the following conditions using a nuclear magnetic resonance spectrum ( ¹ H-NMR spectrum).
Device: Nuclear magnetic resonance device "JNM-LA400" manufactured by JEOL Ltd.
Deuterated solvent: Deuterated chloroform

(Total light transmittance, haze)
For injection-molded or press-molded samples, the total light transmittance and haze were measured using a spectrocolorimeter (“SE5000” manufactured by Nippon Denshoku Kogyo Co., Ltd.) in accordance with JIS-K7361.

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

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

(Mass of each layer or block)
Since the masses of the rubber component layer (aI) and the hard resin component layer (aII) of the multilayer structure polymer particles (a) are almost all reacted with the monomers used, the monomers or a mixture of monomers Calculated based on mass. The masses of the acrylic polymer block (bI) and the methacrylic polymer block (bII) of the block copolymer are obtained by sampling the reaction solution at the time of polymerizing each polymer block, and the nuclear magnetic resonance spectrum ( ¹ H-NMR spectrum). ) Was used for measurement.

The volume fraction (core layer + intermediate layer) (φ) up to the outermost rubber component layer of the multilayer structure polymer particles was calculated from the mass of each layer and the average density of each layer.

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

In the following, "part" means "part by mass".

(Rubber elastic body (B))
(Multilayer structure polymer particles (a));
Production Example 1: Multilayer polymer particles (Ba-1):
Place 100 parts of ion-exchanged water in a glass-lined reaction vessel with a condenser, thermometer and stirrer, followed by a surfactant (polyoxyethylene alkyl ether sodium acetate (NIKKOL-ECT-3NEX)) 0. 019 parts and 0.10 parts of sodium carbonate were added and dissolved. The inside of the reaction vessel was replaced with nitrogen gas to make it substantially oxygen-free. Then, the inside of the reaction vessel was heated to bring the aqueous solution to 80 ° C.

To the aqueous solution, 0.04 part of potassium persulfate was added, and further, a mixture c consisting of 32.6 parts of methyl methacrylate, 2.1 parts of methyl acrylate and 0.07 part of allyl methacrylate was continuously added over 50 minutes. did. After the addition of the mixture c was completed, the mixture was held for 40 minutes and emulsion polymerization was carried out to obtain 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 held for 90 minutes, and seed emulsion polymerization was carried out to obtain 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. It was 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 Latex I-1. Latex I-1 was placed in a container equipped with a stirrer and mixed, and then an aqueous magnesium sulfate solution was added for salting out and solidification. The coagulated product was washed with water, dehydrated and dried to obtain multilayer structure polymer particles (Ba-1). Table 1 shows the physical characteristics of the multilayer structure polymer particles (Ba-1).

Production Example 2; Multilayer Polymer Particles (Ba-2):
Place 100 parts of ion-exchanged water in a glass-lined reaction vessel with a condenser, thermometer and stirrer, then 0.019 parts of surfactant ("Perex SS-H" manufactured by Kao Co., Ltd.) and carbonate. 0.5 part of sodium was added and dissolved. The inside of the reaction vessel was replaced with nitrogen gas to make it substantially oxygen-free. Then, 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 further, a mixture c consisting of 9.4 parts of methyl methacrylate, 0.6 part of methyl acrylate and 0.02 part of allyl methacrylate was continuously added over 20 minutes. did. After the addition of the mixture c was completed, the mixture was held for 30 minutes and emulsion polymerization was carried out to obtain latex c.

Next, 0.07 parts 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 held for 60 minutes, and seed emulsion polymerization was carried out to obtain latex i.

Next, a mixture o consisting of 37.6 parts of methyl methacrylate, 2.4 parts of methyl acrylate and 0.12 parts of n-octyl mercaptan was added to the latex i without interruption over 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 Latex I-2. Latex I-2 was placed in a container equipped with a stirrer and mixed, and then an aqueous magnesium sulfate solution was added for salting out and solidification. The coagulated product was washed with water, dehydrated and dried to obtain multilayer structure polymer particles (Ba-2). Table 1 shows the physical characteristics of the multilayer structure polymer particles (Ba-2).

Production Example 3; Multilayer Polymer Particles (Ba-3):
In a nitrogen atmosphere, 150 parts by mass of distilled water, 1.3 parts by mass of an emulsifier (Kao Corporation "Neoperex G-15"), and a dispersant (Kao) were placed in a polymer equipped with a stirring blade, a cooling tube, and a dropping funnel. "Poise 520" manufactured by the same company) 1.0 part by mass was added and heated to 80 ° C. to uniformly dissolve. Then, at the same temperature, 0.05 parts by mass of potassium persulfate was added, then 41.25 parts by mass of n-butyl acrylate (BA) as an acrylate monomer, and another monofunctional monomer. 8.75 parts by mass of styrene (St), 0.3 parts by mass of allyl methacrylate (ALMA) as a polyfunctional monomer, and 0.25 parts by mass of a surfactant ("Adecacol CS-141E" manufactured by ADEKA). The mixture composed of the parts was added dropwise from the dropping funnel over 60 minutes to form the first layer (layer (Ia)). After completion of the dropping, the reaction was continued at 80 ° C. for another 1 hour, and it was confirmed by gas chromatography that 99% or more of each monomer was consumed.

Next, 0.02 parts by mass of potassium peroxydisulfate was added to the obtained copolymer latex, and then 15.81 parts by mass of n-butyl acrylate (BA) as an acrylate monomer, and other monofunctionality. 3.19 parts by mass of styrene (St) as a monomer, 1.0 part by mass of methyl methacrylate (MMA) as another monofunctional monomer, allyl methacrylate (ALMA) 0 as a polyfunctional monomer A mixture consisting of .16 parts by mass and 0.1 parts by mass of the surfactant (“Adecacol CS-141E”) was added dropwise from the dropping funnel over 40 minutes to form a second layer (layer (Ib)). After completion of the dropping, the reaction was continued at 80 ° C. for another 1 hour, and it was confirmed by gas chromatography that 99% or more of each monomer was consumed.

Next, 0.03 parts by mass of potassium peroxodisulfate was added to the obtained copolymer latex, followed by 28.5 parts by mass of methyl methacrylate (MMA) as a methacrylate ester monomer, and 28.5 parts by mass as another monomer. A mixture consisting 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 ("Adecacol CS-141E") was added dropwise from a dropping funnel over 40 minutes. The third layer was formed (layer (II)). After completion of the dropping, the reaction was continued at 80 ° C. for another 1 hour, and it was confirmed by gas chromatography that 99.9% or more of each monomer was consumed, and the polymerization was completed.

The obtained latex was placed in a container equipped with a stirrer and mixed, and then an aqueous magnesium sulfate solution was added to carry out salting out and solidification. The coagulated product was washed with water, dehydrated and dried to obtain multilayer structure polymer particles (a-3). Table 1 shows the physical characteristics of the multilayer structure polymer particles (a-3).

(Block copolymer (b));
Block copolymer (Bb-1): Consists 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 mass ratio (bII): (bI) of the polymer block is 50:50, and the mass ratio of each monomer (MMA: BA: BzA) = (50:36). : 14), Mw (b1) = 45,000, Mw (b2) = 45,000 diblock copolymer.
Block copolymer (Bb-2): Consists of [methyl methacrylate (MMA) polymer block (bII)]-[n-butyl acrylate (BA)) copolymer block (bI)] and has a weight average molecular weight (Mw). Is 120,000, the mass ratio of the polymer blocks (bII): (bI) is 50:50, the mass ratio of each monomer (MMA: BA) = (50:50), Mw (b1) = 60. A diblock copolymer having 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 (MMA) bII)], the weight average molecular weight (Mw) is 670 million, and the mass ratio (bII) :( bI) :( bII) of the polymer block is 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]
A single shaft of 40 mmφ with 78.9 parts by mass of methacrylic resin (A-1), 8.1 parts by mass of multilayer structure polymer particles (a-1), and 13.0 parts by mass of block copolymer (b-1). It was melt-kneaded at a cylinder temperature of 230 to 250 ° C. using an extruder. Then, 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 Co., Ltd.) set at a cylinder temperature of 250 ° C. and a mold temperature of 50 ° C., a methacrylic resin composition (R1) was put into a JIS test piece mold at a filling speed of 50 mm / s. Injection was performed to obtain molded articles of 10 mm × 80 mm × 4 mm and 50 mm × 50 mm × 3 mm. Table 2 shows the results of physical property evaluation.

[Examples 2 to 9]
The 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, a molded product was obtained using the obtained resin composition in the same manner as in Example 1. Table 2 shows the results of physical property evaluation in each example.

[Comparative Examples 1 to 8]
Thermoplastic resin compositions (R10) to (R17) 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 product was obtained using the obtained resin composition in the same manner as in Example 1. Table 2 shows the results of physical property evaluation in each comparative example.

[Discussion]
In Examples 1 to 9 using the methacrylic resin composition of the present invention containing the specific methacrylic resin (A), the specific multilayer structure polymer particles (a), and the specific block copolymer (b). The obtained molded product had good impact strength while maintaining optical performance and mechanical performance.

On the other hand, a methacrylic resin (A) alone or a methacrylic resin composition composed of the methacrylic resin (A) and the block copolymer (b) and not containing the multilayer structure polymer particles (a). The molded products obtained in Comparative Examples 1 and 2 used had poor impact strength as compared with Examples.

Use a methacrylic resin composition in which the rubber content of one of the multilayer structure polymer particles (a) or the block copolymer (b) is extremely high or low with respect to the rubber content of the other with respect to the total rubber content. The molded products obtained in Comparative Examples 3 to 4 had poor impact strength as compared with Examples having the same rubber content.

Using a thermoplastic resin composition containing multilayer structure polymer particles (Ba-2) and (Ba-3) having a small volume average particle diameter, obtained in Comparative Examples 5 to 7 in which L / de ² ≥ 5.5. The molded product obtained had a poor impact strength as compared with the examples.

The molded products obtained in Comparative Examples 8 and 9 in which L / de ² ≧ 5.5 had poor impact strength as compared with Examples.

Claims (11)

A methacrylic resin composition in which a methacrylic resin (A) forms a matrix and a rubber-like elastic body (B) is dispersed satisfies the following requirements (1) to (4). Acrylic composition.
(1) The particle size distribution of the rubber-like elastic body (B) dispersed in the composition is multimodal, and among the rubber-like elastic bodies (B), one peak having the largest average particle size is the rubber component. The other peak containing two or more layers of the multilayer structure polymer particles (a) containing the layer (aI) and the hard resin component layer (aII) and having the smallest average particle size is the methacrylic polymer block (bII). Includes a block copolymer (b) containing an acrylic polymer block (bI).
(2) The multilayer structure polymer particles (a) satisfy the following formula (W).
L / de ² ≤ 5.5 (W)
L: The theoretical surface-to-surface distance of the multilayer structure polymer particle rubber component layer de: Average particle size of the multilayer structure polymer particle rubber component layer However, the theoretical surface-to-surface distance (L) of the multilayer structure polymer particle rubber component layer is as follows. It is calculated from the formula (X) of.
L = de × ((π / 6φ) ^1/3 -1) (X)
φ: Volume fraction up to the multilayer structure polymer particle rubber component layer (3) The total rubber component content of (aI) and (bI) in the methacrylic resin composition is in the range of 5 to 45% by mass. ..
(4) The ratio of the (bI) content 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. The methacrylic resin composition according to claim 1, wherein the average particle diameter of the multilayer structure polymer particles (a) rubber component layer (aI) is in the range of 0.05 to 0.3 μm. The methacrylic resin composition according to claim 1 or 2, wherein the multilayer structure polymer particles (a) contain 5 to 40% by mass of a rubber component layer (aI). The multilayer structure polymer particles (a) include at least one rubber component layer (aI) and at least one hard resin component layer (aII), and the outermost layer of the particles (a) is a hard resin component layer (aII). The rubber component layer (aI) is an acrylic acid ester monomer unit of 50 to 89.99% by mass, another monofunctional monomer unit of 44.99 to 10% by mass, and a polyfunctional monomer unit. The hard resin component layer (aII) contains a copolymer consisting of 0.01 to 10% by mass, and the methacrylic acid ester monomer unit is 40 to 100% by mass and the other monomer unit is 60 to 0% by mass alone. It contains a polymer or copolymer, and is characterized in that the mass ratio (aI / aII) of the total amount of the rubber component layer (aI) and the total amount of the hard resin component layer (bI) is 30/70 to 90/10. The methacrylic resin composition according to any one of claims 1 to 3. The methacrylic resin according to any one of claims 1 to 4, wherein the methacrylic resin composition contains 3 to 10% by mass of the acrylic polymer block (bI) of the block copolymer (b). Acrylic composition. Claim that the acrylic polymer block (bI) of the block copolymer (b) is a copolymer block of 50 to 90% by mass of acrylic acid alkyl ester and 50 to 10% by mass of (meth) acrylic acid aromatic ester. Item 2. The methacrylic resin composition according to any one of Items 1 to 5. The methacrylic resin composition according to claim 6, wherein the (meth) acrylic acid aromatic ester is benzyl acrylic acid. Weight average molecular weights of methacrylic polymer block (bII) and acrylic polymer block (bI) of block copolymer (b) Mw (bII), Mw (bI) and methacrylic resin (A) weight average molecular weight Mw The methacrylic resin composition according to any one of claims 1 to 7, 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) A molded product containing the methacrylic resin composition according to any one of claims 1 to 8. The molded product according to claim 9, which is an injection molded product. A method for producing a film, which comprises a step of melt extrusion or solution casting of the methacrylic resin composition according to any one of claims 1 to 8.