JP2021130745A - Multilayer structure polymer particle, thermoplastic resin composition containing the same, molding, and film - Google Patents

Abstract

To provide multilayer structure polymer particles which are excellent in reduction in spitting faults at the time of formation of a film, and can suppress poor appearance and mold dirt generated at the time of processing of a molding, and a thermoplastic resin composition containing the same, a molding and a film.SOLUTION: Multilayer structure polymer particles having an inner layer containing a crosslinked rubber (I) layer and an outer layer containing a thermoplastic resin (II) graft-bonded to the inner layer have a weight reduction ratio at 200-280°C when a temperature is raised from 200°C at a rate of 1°C/min under nitrogen atmosphere by thermogravimetric measurement of 5% or less.SELECTED DRAWING: None

Description

The present invention relates to multilayer structure polymer particles, a thermoplastic resin composition containing the same, a molded product, and a film.

(Meta) Acrylic resins are used in various fields because they have excellent transparency, color tone, appearance, weather resistance, luster and processability. In particular, films formed from (meth) acrylic resins are widely used in optical applications, decorative applications, etc. because they have high transparency, low moisture permeability, and are easy to perform primary and secondary processing.

On the other hand, (meth) acrylic resins are generally brittle and lack impact resistance. Therefore, in order to supplement this property, impact resistance and strength are improved by blending the particles of the graft copolymer having a crosslinked rubber layer and having a specific particle size with the (meth) acrylic resin. Techniques for making the particles have been proposed (Patent Documents 1 to 3).
However, a molded product using a resin composition obtained by melt-kneading such graft copolymer particles and a (meth) acrylic resin has a decrease in impact resistance due to poor dispersion, and has defects such as lumps and fish eyes. May occur. In addition, especially when the molding temperature becomes high, the defects caused by the thermal decomposition of the resin and the substances generated by the thermal decomposition may cause bubbles (silver streaks) in the molded product or stain the mold. be.
Therefore, as a method for solving such a problem, organic fine particles obtained by further polymerizing a (meth) acrylic acid ester as a shell portion on a particulate polymer having an average particle diameter of 0.01 μm to 1 μm as a core portion are added. A method to be used has been proposed (Patent Document 4). Further, as a method of suppressing mold stains, a method of adding an antioxidant to the multilayer structure polymer particles has been proposed (Patent Document 5).

Japanese Unexamined Patent Publication No. 48-55233 International Publication No. 2016/139927 International Publication No. 2017/20243 JP-A-2007-254727 Japanese Unexamined Patent Publication No. 2012-180454

The method disclosed in the patent document has been desired to be improved because it may not be possible to reduce the defects of the film or the molded product or it may lead to an increase in cost.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide multilayer structure polymer particles capable of suppressing the occurrence of defects, poor appearance, and mold stains during processing into a molded product or film. And. Another object of the present invention is to provide a thermoplastic resin composition, a molded product and a film containing the same.

As a result of diligent studies on the above problems, the present inventors have made use of multilayer structure polymer particles having a weight loss rate of a specific value or less, which causes the occurrence of bump defects in films, molded products, etc., poor appearance, and stains on molds. We have found that it is possible to suppress the above, and completed the present invention.

That is, the present invention is the following [1] to [15].
[1] Multilayered polymer particles having an inner layer including a crosslinked rubber (I) layer and an outer layer containing a thermoplastic resin (II) graft-bonded to the inner layer under a nitrogen atmosphere by thermogravimetric analysis. Multilayered polymer particles having a weight loss rate of 5% or less at 200 ° C. to 280 ° C. when the temperature is raised from 200 ° C. to 1 ° C./min.
[2] The multilayer structure polymer particles according to the above [1], wherein the mass ratio [V2 / V1] is 0.30 or more when the mass of the inner layer is V1 and the mass of the outer layer is V2.
[3] The multilayer structure polymer particles according to the above [1] or [2], wherein the acetone solubility is 45% by mass or less.
[4] The multilayer structure polymer particles according to any one of the above [1] to [3], wherein the median diameter measured by the laser diffraction-scattering method is 80 to 500 nm.
[5] The multilayer structure polymer particle according to any one of the above [1] to [4], wherein the thermoplastic resin (II) has a number average molecular weight of 20,000 to 50,000.
[6] The crosslinked rubber (I) has an acrylic acid ester unit of 50.0 to 99.0% by mass and a polyfunctional monomer unit of 0.01 to 5.0% by mass, and can be copolymerized with these. Contains 0.01 to 49.0% by mass of unsaturated monomer units, and the thermoplastic resin (II) contains 40.0 to 99.0% by mass of methacrylic acid ester units, and other copolymerizable products thereof. The multilayer structure polymer particle according to any one of the above [1] to [5], which contains 0.1 to 60.0% by mass of an unsaturated monomer unit.
[7] A thermoplastic resin composition containing 5 to 95% by mass of the thermoplastic resin (III) and 5 to 95% by mass of the multilayer structure polymer particles according to any one of the above [1] to [6].
[8] The thermoplastic resin composition according to the above [7], wherein the thermoplastic resin (III) is an amorphous resin.
[9] The thermoplastic resin composition according to the above [7] or [8], wherein the glass transition temperature of the thermoplastic resin (III) is 50 to 170 ° C.
[10] The thermoplastic resin composition according to any one of the above [7] to [9], wherein the thermoplastic resin (III) has a number average molecular weight of 10,000 to 500,000.
[11] The thermoplastic resin composition according to any one of the above [7] to [10], wherein the thermoplastic resin (III) is a (meth) acrylic resin.
[12] The heat according to the above [11], wherein the (meth) acrylic resin contains 80.0 to 99.9% by mass of a methacrylic acid ester unit and 0.1 to 20.0% by mass of an acrylic acid ester unit. Plastic resin composition.
[13] A molded product made of the thermoplastic resin composition according to any one of the above [7] to [12].
[14] A film comprising the thermoplastic resin composition according to any one of the above [7] to [12].
[15] A molded product containing the multilayer structure polymer particles according to any one of the above [1] to [6].

According to the present invention, it is possible to provide multilayer structure polymer particles capable of suppressing the occurrence of bump defects, poor appearance, and mold stains during processing into a molded product or film. Further, it is possible to provide a thermoplastic resin composition, a molded product and a film containing the same.

The multilayer structure polymer particles according to the embodiment of the present invention, wherein the inner layer is composed of one layer (first layer) and the outer layer is composed of two layers (second layer and third layer). It is a figure which shows the particle. The multilayer structure polymer particles according to the embodiment of the present invention, wherein the inner layer is composed of two layers (first layer and second layer) and the outer layer is composed of one layer (third layer). It is a figure which shows the particle. The multilayer structure polymer particles according to the embodiment of the present invention, wherein the inner layer is composed of two layers (first layer and second layer) and the outer layer is composed of two layers (third layer and fourth layer). It is a figure which shows the multilayer structure polymer particles. The multilayer structure polymer particles according to the embodiment of the present invention, wherein the inner layer is composed of two layers (first layer and second layer) and the outer layer is composed of two layers (third layer and fourth layer). It is a figure which shows the multilayer structure polymer particles.

[Multilayer polymer particles]
Multilayered polymer particles having an inner layer including a crosslinked rubber (I) layer and an outer layer containing a thermoplastic resin (II) graft-bonded to the inner layer, and measured at 200 ° C. under a nitrogen atmosphere by thermogravimetric analysis. The weight loss rate of 200 ° C. to 280 ° C. when the temperature is raised at a rate of 1 ° C./min is 5% or less.

In the multilayer structure polymer particles of the present invention, the weight loss rate of 200 ° C. to 280 ° C. when the temperature is raised from 200 ° C. to 1 ° C./min in a nitrogen atmosphere by thermogravimetric analysis is set to 5% or less. .. It is considered that when the weight reduction rate exceeds 5%, the defects caused by the thermal decomposition component increase and the mold becomes dirty. From such a viewpoint, the weight reduction rate is preferably 4% or less, more preferably 3% or less, and further preferably 2% or less.
The weight loss rate in the present invention is such that the sample is heated to 200 ° C. at 20 ° C./min in a nitrogen atmosphere using a thermogravimetric measuring device, and then from 200 ° C. to 300 ° C. at 1 ° C./min. It can be obtained by measuring the weight loss rate at 200 ° C. to 280 ° C. when the temperature is raised. Specifically, it can be measured by the method described in Examples.

The weight reduction rate is appropriately determined by adjusting the mass ratio [V2 / V1], for example, when the mass of the inner layer of the multilayer structure polymer particles is V1 and the mass of the outer layer of the multilayer structure polymer particles is V2. Can be set.
For example, the mass ratio [V2 / V1] is preferably 0.30 or more, more preferably 0.40 to 0.78, further preferably 0.50 to 0.75, and 0. It is even more preferably .60 to 0.73. When the mass ratio [V2 / V1] is 0.30 or more, the thermal decomposability is improved and the occurrence of lump defects can be suppressed.

In the multilayer structure polymer particles of the present invention, when the crosslinked rubber layer is one layer, the crosslinked rubber layer is referred to alone, or the crosslinked rubber layer and the inner layer thereof are collectively referred to as an "inner layer", and the crosslinked rubber layer is referred to as an "inner layer". The layer outside the rubber layer is called the "outer layer". On the other hand, when two or more crosslinked rubber layers are provided, the outermost crosslinked rubber layer and the layer inside the crosslinked rubber layer are collectively referred to as an "inner layer", and the layer outside the crosslinked rubber layer is referred to as "inner layer". It is called "outer layer". Specific examples of the multilayer structure polymer particles of the present invention are illustrated in FIGS. 1 to 4.
FIG. 1 shows multilayer structure polymer particles having one crosslinked rubber layer, in which the crosslinked rubber layer independently forms an inner layer, and the crosslinked PMMA (polymethylmethacrylate) layer and PMMA outside the crosslinked rubber layer. It is a figure which shows the multilayer structure polymer particle whose layer constitutes an outer layer. Further, FIG. 2 is a diagram showing multilayer structure polymer particles in which a crosslinked rubber layer and a crosslinked PMMA layer inside the crosslinked rubber layer form an inner layer, and a PMMA layer outside the crosslinked rubber layer forms an outer layer.
Further, FIG. 3 is a diagram showing multilayer structure polymer particles in which a crosslinked rubber layer and a crosslinked PMMA layer inside the crosslinked rubber layer form an inner layer, and two PMMA layers outside the crosslinked rubber layer form an outer layer. FIG. 4 is a diagram showing multilayer structure polymer particles in which the crosslinked rubber layer and the crosslinked PMMA layer inside the crosslinked rubber layer form an inner layer, and the crosslinked PMMA layer and the PMMA layer outside the crosslinked rubber layer form an outer layer. be.

<Inner layer>
The inner layer in the present invention contains the crosslinked rubber (I).
[Crosslinked rubber (I)]
The crosslinked rubber (I) constituting the inner layer is not particularly limited, and is butadiene rubber, styrene-butadiene rubber, isoprene rubber, chloroprene rubber, acrylonitrile-butadiene rubber, butyl rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, urethane. Examples thereof include rubber, silicone rubber, fluororubber, chlorosulfonated polyethylene rubber, acrylic rubber, etc. Among these, acrylic rubber is preferable.

The acrylic rubber used for the crosslinked rubber (I) has a structural unit derived from an acrylic acid ester (hereinafter, also referred to as “acrylic acid ester unit”) and a structural unit derived from a polyfunctional monomer (hereinafter, “polyfunctional”). It is preferable to include "sex monomer unit"). By including the structural unit derived from the polyfunctional monomer, the crosslinked rubber (I) and the thermoplastic resin (II) can be graft-bonded.

Examples of the acrylic acid ester used for the crosslinked rubber (I) include an acrylic acid ester which is a hydrocarbon group having 1 to 12 carbon atoms in which the ester portion may have a substituent. Specifically, methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, hydroxyhexyl acrylate. , Isobornyl acrylate, tetrahydrofurfuryl acrylate, phenyl acrylate, cyclohexyl acrylate, benzyl acrylate and the like. Among these, an acrylic acid ester which is a hydrocarbon group having 1 to 6 carbon atoms in which the ester moiety may have a substituent is preferable, 2-ethylhexyl acrylate and n-butyl acrylate are more preferable, and n-butyl acrylate is more preferable. Is more preferable. One of these may be used alone, or two or more thereof may be used in combination.

The content of the acrylic acid ester unit in the crosslinked rubber (I) is preferably 50.0 to 99.0% by mass, more preferably 60.0 to 98.0% by mass, and 70.0 to 90.0% by mass. It is further preferably 97.0% by mass, and even more preferably 75.0 to 96.0% by mass. When the content of the acrylic acid ester unit is within this range, the impact resistance of the multilayer structure polymer particles can be improved.

Examples of the polyfunctional monomer used for the crosslinked rubber (I) include ethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, divinylbenzene, and allyl methacrylate. , Allyl acrylate, allyl maleate, allyl fumarate, diallyl fumarate, triallyl cyanurate and the like. Among these, allyl acrylate and allyl methacrylate are preferable, and allyl methacrylate is more preferable. One of these may be used alone, or two or more thereof may be used in combination.

The content of the polyfunctional monomer unit in the crosslinked rubber (I) is preferably 0.01 to 5.0% by mass, more preferably 0.1 to 4.5% by mass. It is more preferably 1.0 to 4.0% by mass. When the content of the polyfunctional monomer unit is within this range, the desired graft ratio can be achieved.

The crosslinked rubber (I) may further contain other unsaturated monomers copolymerizable with the acrylic acid ester and / or polyfunctional monomer. Other unsaturated monomers include, for example, 1,3-butadiene, 1,2-butadiene, isoprene, styrene, α-methylstyrene, vinyltoluene, methylmethacrylate, ethylmethacrylate, n-butylmethacrylate, n-propylmethacrylate. , I-propyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, lauryl methacrylate, hydroxyhexyl methacrylate, isobornyl methacrylate, tetrahydrofurfuryl methacrylate, phenyl methacrylate, cyclohexyl methacrylate, benzyl Examples thereof include methacrylate, acrylonitrile, and methacrylonitrile. Among these, styrene is preferable from the viewpoint of improving transparency. One of these may be used alone, or two or more thereof may be used in combination.

When the crosslinked rubber (I) contains the other unsaturated monomer, the content thereof is preferably 0.01 to 49.0% by mass, preferably 1.0 to 39.0% by mass. Is more preferable, and 2.0 to 29.0% by mass is further preferable.

[Cross-linked hard body]
The inner layer of the multilayer structure polymer particles of the present invention may be a single layer of a layer containing a crosslinked rubber (I), or may be two or more layers each containing a crosslinked rubber (I) having a different composition. , One or two or more layers having a composition different from that of the crosslinked rubber (I) may be contained, but from the viewpoint of improving the strength of the multilayer structure polymer particles, the innermost layer containing the crosslinked hard material (for example, FIGS. And the crosslinked PMMA layer shown in 4) are preferably included. The multilayer structure polymer particles of the present invention particularly preferably have a three-layer structure of a crosslinked hard body, a crosslinked rubber (I), and a thermoplastic resin (II).

The crosslinked hard body preferably contains a structural unit derived from a methacrylic acid ester (hereinafter, also referred to as “methacrylic acid ester unit”). Specifically, as the methacrylic acid ester, a methacrylic acid ester in which the ester portion is an alkyl group having 1 to 4 carbon atoms is preferable, and methyl methacrylate is particularly preferable.

The content of the methacrylic ester unit in the crosslinked hard body is preferably 40.0 to 99.0% by mass, more preferably 50.0 to 98.0% by mass, and 60.0 to 97%. It is more preferably 0.0% by mass. When the content of the methacrylic ester unit is within this range, the strength of the multilayer structure polymer particles can be improved.

Further, the crosslinked hard body preferably contains a structural unit derived from an acrylic acid ester. Examples of the acrylic acid ester include an ester in which the ester moiety is a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent. Specifically, methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, hydroxyhexyl acrylate. , Isobornyl acrylate, tetrahydrofurfuryl acrylate, phenyl acrylate, cyclohexyl acrylate, benzyl acrylate and the like. Among these, an acrylic acid ester which is a hydrocarbon group having 1 to 6 carbon atoms in which the ester moiety may have a substituent is preferable, methyl acrylate, 2-ethylhexyl acrylate, and n-butyl acrylate are more preferable, and methyl. Acrylate is more preferred. One of these may be used alone, or two or more thereof may be used in combination.

The content of the acrylic acid ester unit in the crosslinked hard body is preferably 0.1 to 20.0% by mass, more preferably 1.0 to 15.0% by mass, and 3.0 to 10%. It is more preferably 0% by mass. When the content of the acrylic acid ester unit is within this range, the impact resistance of the multilayer structure polymer particles can be improved.

Further, the crosslinked hard body preferably contains a structural unit derived from a polyfunctional monomer. Examples of the polyfunctional monomer used for the crosslinked hard material include ethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, divinylbenzene, allyl methacrylate, and allyl. Examples thereof include acrylate, allyl maleate, allyl fumarate, diallyl fumarate, and triallyl cyanurate. Among these, allyl acrylate and allyl methacrylate are preferable, and allyl methacrylate is more preferable. One of these may be used alone, or two or more thereof may be used in combination.

The content of the polyfunctional monomer unit in the crosslinked hard body is preferably 0.01 to 3.0% by mass, more preferably 0.1 to 2.0% by mass. When the content of the polyfunctional monomer unit is within this range, it is easy to adjust the hardness to a desired level.

<Outer layer>
The outer layer of the multilayer structure polymer particles of the present invention is a layer containing a thermoplastic resin (II) graft-bonded to the inner layer. The outer layer may be composed of a thermoplastic resin (II) and another resin. From the viewpoint of compatibility with the matrix resin and ease of production, the outer layer of the multilayer structure polymer particles of the present invention preferably contains 50% by mass or more of the thermoplastic resin (II), and preferably contains 70% by mass or more. Is more preferable, 90% by mass or more is further preferable, 95% by mass or more is more preferable, and it may be composed of only the thermoplastic resin (II).

[Thermoplastic resin (II)]
The thermoplastic resin (II) is not particularly limited, and is composed of polyethylene, polypropylene, polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene, polyvinyl acetate, polyurethane, polytetrafluoroethylene, polyamide, polycarbonate, polyester, polyethylene terephthalate, and the like. Examples thereof include polybutylene terephthalate, polyacetal, (meth) acrylic resin, and thermoplastic elastomer, and among these, (meth) acrylic resin is preferable.

The (meth) acrylic resin used as the thermoplastic resin (II) preferably contains a methacrylic ester unit.
As the methacrylic acid ester used for the thermoplastic resin (II), a methacrylic acid ester in which the ester portion is an alkyl group having 1 to 4 carbon atoms is preferable, and methyl methacrylate is particularly preferable. As the methacrylic acid ester used for the thermoplastic resin (II), one type may be used alone, or two or more types may be used in combination.

The content of the methacrylic ester unit in the thermoplastic resin (II) is preferably 40.0 to 99.9% by mass, more preferably 50.0 to 98.0% by mass, and 60. It is more preferably 0 to 97.0% by mass. When the content of the methacrylic ester unit is within this range, the strength of the multilayer structure polymer particles can be appropriately maintained.

The thermoplastic resin (II) can further contain structural units derived from other unsaturated monomers copolymerizable with the monomer. Specific examples of other unsaturated monomers include methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, and 2-ethylhexyl acrylate. , N-octyl acrylate, lauryl acrylate, hydroxyhexyl acrylate, isobornyl acrylate, tetrahydrofurfuryl acrylate, phenyl acrylate, cyclohexyl acrylate, benzyl acrylate and the like. Among these, methyl acrylate is preferable from the viewpoint of cost.
As the other unsaturated monomer used in the thermoplastic resin (II), one type may be used alone, or two or more types may be used in combination.

When the thermoplastic resin (II) contains the unsaturated monomer, the content may be 0.10 to 60.00% by mass, or 2.00 to 50.00% by mass. It may be 3.00 to 40.00% by mass, but from the viewpoint of thermal decomposition resistance, the upper limit value is preferably 25.00% by mass, more preferably 12.00% by mass. , 8.00% by mass is more preferable. The lower limit may be 4.00% by mass.

The number average molecular weight of the thermoplastic resin (II) is preferably 20,000 to 50,000, more preferably 21,000 to 45,000, and preferably 22,000 to 40,000. It is even more preferably 30,000 to 40,000. When the number average molecular weight of the thermoplastic resin (II) is within the above range, it is possible to obtain multilayer structure polymer particles having excellent thermal stability at the retention portion during film formation or the like.

It is difficult to directly measure the number average molecular weight of the thermoplastic resin (II) graft-bonded to the inner layer from the multilayer structure polymer particles. Therefore, in the present invention, in order to measure the number average molecular weight of the thermoplastic resin (II), the thermoplastic resin (II) which is not graft-bonded to the inner layer is manufactured under the same conditions as when graft-bonded to the inner layer. , The number average molecular weight of the thermoplastic resin (II) grafted is estimated from the number average molecular weight of the resin. The number average molecular weight of the non-graft-bonded thermoplastic resin (II) can be determined by gel permeation chromatography (GPC) based on the molecular weight of standard polystyrene, and specifically, it is determined by the method described in Examples. be able to.

<Manufacturing method of multilayer polymer particles>
The method for producing the multilayer structure polymer particles of the present invention is not particularly limited, but it is preferably produced by the emulsion polymerization method from the viewpoint of ease of controlling the particle size and the like. Specifically, for example, a polymerization reaction step (S1) for forming a crosslinked hard body, a polymerization reaction step (S2) for forming a layer containing a crosslinked rubber (I), and a polymerization for forming a layer containing a thermoplastic resin (II). It can be produced by carrying out the reaction step (S3) in the order of lamination. Hereinafter, the emulsion polymerization method will be described as an example.

In the polymerization reaction steps (S1) and (S2), a monomer mixture corresponding to the composition of the crosslinked hard body and the crosslinked rubber (I) can be copolymerized by a known method, and specifically, an emulsifier and pH. To carry out a polymerization reaction by mixing a modifier, a polymerization initiator, a monomer mixture, a chain transfer agent, etc. with water and heating them to obtain a crosslinked hard body emulsion and a crosslinked rubber (I) emulsion, respectively. Can be done.

After performing the polymerization reaction step (S1), a monomer mixture corresponding to the composition of the crosslinked rubber (I), a polymerization initiator, a chain transfer agent and the like are added to the emulsion to crosslink as the inner first layer. A hard body and a layer containing the crosslinked rubber (I) as the second layer can be obtained. In addition, (S1) and (S2) may be performed a plurality of times, respectively.

In the polymerization reaction step (S3), the multilayer structure polymer of the present invention is polymerized by adding (co) a monomer mixture, a polymerization initiator, and a chain transfer agent corresponding to the composition of the thermoplastic resin (II) to the emulsion. Particles can be obtained.

The emulsifier used in the polymerization reaction steps (S1) to (S3) is not particularly limited as long as it is an emulsifier used for emulsion polymerization, but an anionic emulsifier, a nonionic emulsifier and the like can be used. These emulsifiers can be used alone or in combination of two or more.
Examples of the anionic emulsifier include dialkyl sulfosuccinates such as sodium dioctyl sulfosuccinate and sodium dilauryl sulfosuccinate; alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate; alkyl sulfates such as sodium dodecyl sulphate; polyoxyethylene nonylphenyl. Polyoxyethylene nonylphenyl ether sulfate such as ether sodium sulfate; polyoxyethylene alkyl ether sulfate such as polyoxyethylene alkyl ether sulfate; alkyl ether carboxylate such as polyoxyethylene tridecyl ether sodium acetate and the like can be mentioned. ..
Examples of the nonionic emulsifier include polyoxyethylene alkyl ether and polyoxyethylene nonylphenyl ether.

The polymerization initiator used in the polymerization reaction steps (S1) to (S3) is not particularly limited as long as it generates reactive radicals, and is, for example, tert-hexylperoxyisopropyl monocarbonate, tert-hexylperoxy 2. -Ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy2-ethylhexanoate, tert-butylperoxypivalate, tert-hexylperoxypivalate, tert-butylperoxyneodecanoe -To, tert-hexyl peroxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1,1-bis (tert-hexylperoxy) cyclohexane, benzoylperoxide, 3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, 2,2'-azobis (2-methylpropionitrile), 2,2'-azobis (2-methylbutyronitrile), dimethyl 2,2 ′ -Azobis (2-methylpropionate), potassium persulfate, ammonium persulfate, sodium persulfate and the like can be mentioned. Of these, potassium persulfate is preferable.

The amount of the polymerization initiator is preferably 0.001 to 0.5 parts by mass with respect to 100 parts by mass of each of the monomer mixtures in the polymerization reaction steps (S1) to (S3), and is 0.01. It is more preferably ~ 0.4 parts by mass, and further preferably 0.05 to 0.3 parts by mass.

Examples of the chain transfer agent used in the polymerization reaction steps (S1) to (S3) include n-octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, 1,4-butanedithiol, 1,6-hexanedithiol, and ethylene. Glycol bisthiopropionate, butanediol bisthioglycolate, butanediol bisthiopropionate, hexanediol bisthioglycolate, hexanediol bisthiopropionate, trimetylolpropanthris- (β-thiopropionate) , Pentaerythritol tetrakisthiopropionate and the like. Of these, n-octyl mercaptan and n-dodecyl mercaptan are preferable, and n-octyl mercaptan is more preferable. One of these may be used alone, or two or more thereof may be used in combination.

The amount of the chain transfer agent used can be appropriately adjusted, but the amount used in the polymerization reaction step (S3) is preferably 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the polymerization reaction raw material. It is more preferably 0.03 to 0.3 parts by mass, further preferably 0.05 to 0.2 parts by mass, and particularly preferably 0.08 to 0.15 parts by mass. When the amount of the chain transfer agent used is within the above range, the weight loss rate can be kept low.

The multilayer structure polymer particles can be taken out and purified from the emulsion containing the multilayer structure polymer particles obtained by the emulsion polymerization method by a known method. For example, it can be carried out by freeze-coagulation or washing with water.

The amount of the chain transfer agent used in the monomer mixture used in the polymerization reaction step (S3) is preferably 0.01 to 0.2% by mass, preferably 0.02 to 0.18% by mass. It is more preferably 0.03 to 0.17% by mass, further preferably 0.05 to 0.15% by mass.
The amount of the chain transfer agent used is preferably 1 to 199 parts by mass, more preferably 5 to 190 parts by mass with respect to 100 parts by mass of the polymerization initiator used in the polymerization reaction step (S3). It is preferably 10 to 150 parts by mass, and more preferably 10 to 150 parts by mass.

<Acetone solubility>
The acetone solubility of the multilayer structure polymer particles of the present invention is preferably 45% by mass or less, more preferably 30% by mass or less, further preferably 25% by mass or less, and 20% by mass. It is more preferably less than or equal to, more preferably 15% by mass or less, particularly preferably 10% by mass or less, and preferably 1% by mass or more, and 2% by mass or more. More preferably, it is more preferably 5% by mass or more. When the acetone solubility is not more than the above upper limit value, the thermal stability of the multilayer structure polymer particles at the time of film formation of the matrix resin (base resin) and the multilayer structure polymer particles is improved, and the weight of the multilayer structure polymer particles is improved. The rate of decrease can be kept low. Further, when the acetone solubility is at least the above lower limit value, the crosslinked rubber (I) and the thermoplastic resin (II), that is, the inner layer and the outer layer are sufficiently graft-bonded, which is preferable.
The acetone solubility can be adjusted by adjusting the blending amount of the polyfunctional monomer, the blending amount of the chain transfer agent, and the like.
The acetone solubility of the multilayer structure polymer particles of the present invention is the ratio of the thermoplastic resin (II) in which the multilayer structure polymer particles are dissolved in acetone and not graft-bonded to the mass of the multilayer structure polymer particles. .. The acetone solubility (% by mass) can be determined by the method described in Examples.

<Median diameter De>
For the emulsion of the multilayer structure polymer particles of the present invention, the median diameter De measured by the laser diffraction-scattering method is preferably 80 to 500 nm, more preferably 150 to 400 nm, and more preferably 200 to 300 nm. Is even more preferable. When the median diameter De of the multilayer structure polymer particles is within the above range, the required impact resistance can be obtained.
Here, the median diameter De of the multilayer structure polymer particles is an average value of the outer diameters of the multilayer structure polymer particles, and can be specifically obtained by the method described in Examples.

[Thermoplastic resin composition]
The thermoplastic resin composition of the present invention contains 5 to 95% by mass of the multilayer structure polymer particles of the present invention and 5 to 95% by mass of the thermoplastic resin (III). When the content of the multilayer structure polymer particles in the thermoplastic resin composition is within the above range, the impact resistance of the molded product can be improved. From this viewpoint, the content of the multilayer structure polymer particles in the thermoplastic resin composition is preferably 7 to 80% by mass, more preferably 10 to 60% by mass, and 15 to 50% by mass. It is more preferable to have.
Further, from the same viewpoint, the content of the thermoplastic resin (III) in the thermoplastic resin composition of the present invention is 5 to 95% by mass, preferably 20 to 93% by mass, preferably 40 to 90%. It is more preferably by mass, and even more preferably 50 to 85% by mass.

The thermoplastic resin (III) is a resin that can be a multilayer structure polymer particles and a matrix resin (base resin), and the same resins as those listed as the thermoplastic resin (II) can be used, but is amorphous. It is preferably a resin. Examples of the amorphous resin that can be used as the thermoplastic resin (III) include polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene, polycarbonate, (meth) acrylic resin, thermoplastic elastomer, and the like, and in particular (meth). ) Acrylo-based resin is preferably used.
When the thermoplastic resin (III) is a (meth) acrylic resin, the methacrylic ester constituting the (meth) acrylic resin is preferably a methacrylic ester in which the ester portion is an alkyl group having 1 to 4 carbon atoms. , Methyl methacrylate is particularly preferred. As the methacrylic acid ester used for the thermoplastic resin (III), one type may be used alone, or two or more types may be used in combination.

Examples of the acrylic acid ester used in the thermoplastic resin (III) include an ester in which the ester moiety is a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent. Specifically, methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, hydroxyhexyl acrylate. , Isobornyl acrylate, tetrahydrofurfuryl acrylate, phenyl acrylate, cyclohexyl acrylate, benzyl acrylate and the like. Among these, an ester in which the ester moiety is a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent is preferable, methyl acrylate, 2-ethylhexyl acrylate, and n-butyl acrylate are more preferable, and methyl acrylate is preferable. More preferred. One of these may be used alone, or two or more thereof may be used in combination.

The thermoplastic resin (III) is preferably a (meth) acrylic resin containing 80.0 to 99.9% by mass of methacrylic acid ester units and 0.1 to 20.0% by mass of acrylic acid ester units. It is more preferable that the (meth) acrylic resin contains 85.0 to 99.8% by mass of the methacrylic acid ester unit and 0.2 to 15.0% by mass of the acrylic acid ester unit, and the methacrylic acid ester unit is 90. A (meth) acrylic resin containing 0 to 99.7% by mass and 0.3 to 10.0% by mass of an acrylic ester unit is more preferable.

The glass transition temperature (Tg) of the thermoplastic resin (III) is preferably 50 to 170 ° C, more preferably 70 to 150 ° C, and even more preferably 90 to 140 ° C. When the glass transition temperature (Tg) of the thermoplastic resin (III) is within the above range, stable film formation can be achieved.
The glass transition temperature of the thermoplastic resin (III) can be measured in accordance with JIS K7121: 2012, and specifically, it can be measured by the method described in Examples. A differential scanning calorimetry (DSC) device (eg, manufactured by TA; Q20) can be used for the measurement. The measurement condition of the DSC curve is that the sample is once heated to 230 ° C., then cooled to −90 ° C., and then heated from −90 ° C. to 230 ° C. at 10 ° C./min. The intermediate point glass transition temperature is obtained from the DSC curve measured at the time of the second temperature rise, and the intermediate point glass transition temperature is defined as the glass transition temperature (Tg).

The number average molecular weight of the thermoplastic resin (III) is preferably 10,000 to 500,000, more preferably 20,000 to 200,000, and preferably 25,000 to 100,000. More preferred. When the number average molecular weight of the thermoplastic resin (III) is within the above range, appropriate strength can be exhibited when the thermoplastic resin composition of the present invention is used as a molded product such as a film.

[Molded body, film]
The molded product of the present invention contains the multilayer structure polymer particles of the present invention. Further, the molded product and film of the present invention are made of the thermoplastic resin composition of the present invention. Since the molded product and film of the present invention use multilayer structure polymer particles having excellent heat-resistant decomposition properties, it is possible to suppress the occurrence of bump defects during processing into the molded product and film.
The film of the present invention is suitably used for optical members such as a polarizer protective film, a retardation film, a retardation plate, a light diffusing plate, and a light guide plate.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. The measurement of physical property values was carried out by the following method. The abbreviations of the monomers and the like used in Examples and Comparative Examples are as follows.

MMA: Methyl Methacrylate ALMA: Allyl Methacrylate MA: Methyl Acrylate BA: n-Butyl Acrylate St: Styrene n-OM: n-octyl mercaptan

[Weight loss rate]
Using a thermogravimetric analyzer (manufactured by Shimadzu Corporation: TA-50), the temperature of 10 mg of the sample was raised to 200 ° C. at 20 ° C./min under a nitrogen atmosphere (flow rate 50 mL / min), and then from 200 ° C. to 1 The weight loss rate at 200 ° C. to 280 ° C. when the temperature was raised to 300 ° C. at ° C./min was measured.

[Acetone solubility]
2 g of the powder of the multilayer structure polymer particles was precisely weighed and used as the mass (W1) of the sample. The finely weighed powder was immersed in 118 mL of acetone at 25 ° C. for 24 hours. Then, the powder and acetone were stirred to uniformly disperse the multilayer structure polymer particles in acetone, and this was used as a preparation liquid.
Next, 30 g of each of the preparations was taken into four stainless steel centrifuge tubes. The centrifuge tube was weighed in advance. The centrifuge tube was centrifuged at a temperature of 0 ° C. and a rotation speed of 20,000 rpm for 90 minutes with a high-speed cooling centrifuge (manufactured by Hitachi, Ltd .: CR22GIII). The supernatant was decanted from each centrifuge tube. Then, 30 g of acetone was newly added to each centrifuge tube. The precipitate and acetone were stirred. After centrifuge tube was centrifuged again, the supernatant was taken out. Stirring, centrifugation and removal of the supernatant were repeated a total of 4 times. From the above, the acetone-soluble component was sufficiently taken out.
Then, in order to remove acetone from the supernatant liquid, acetone was removed using an evaporator. The eggplant flask from which acetone was removed was dried in vacuum. The polymer (mass of acetone-soluble component; W2) remaining in the eggplant flask after drying was weighed, and the acetone solubility of the multilayer structure polymer particles was calculated by calculating based on the following formula.
Acetone solubility (mass%) = mass of acetone-soluble component (W2) / mass of multilayer polymerized particles (W1) x 100

[Median diameter De]
The emulsion containing the multilayer structure polymer particles obtained by emulsion polymerization was diluted 200-fold with water. The aqueous dispersion was analyzed by a laser diffraction / scattering particle size distribution measuring device (manufactured by HORIBA, Ltd .: LA-950V2), and the median diameter De was calculated from the analyzed values. At this time, the refractive indexes of the multilayer structure polymer particles and water were set to 1.4900 and 1.3333, respectively.

[Number average molecular weight]
Based on the value measured by GPC (gel permeation chromatography), it was determined as a polystyrene-equivalent molecular weight. The measurement conditions were as follows.
Equipment: GPC equipment "HCL-8320" manufactured by Tosoh Corporation
Separation column: Tosoh Corporation "TTSKguradcolum SuperHZ-H", "TSKgel HZM-M" and "TSKgel SuperHZ4000" are connected in series Eluent: Tetrahydrofuran Eluent Flow rate: 0.35 mL / min Column temperature: 40 ° C.
Detection method: Differential refractometer (RI) method

[Number average molecular weight of thermoplastic resin (II)]
The acetone-soluble component obtained in the measurement of the acetone solubility was sufficiently dried, 10 mg was precisely weighed, 5 mL of THF was added, and the mixture was stirred for 3 hours, and then the acetone-soluble component of the multilayer structure polymer particles was mixed with THF. It was evenly dispersed therein. The sample prepared as described above was measured by GPC under the above conditions, and the number average molecular weight of the thermoplastic resin (II) was measured.

[Disadvantages of film]
The pellets of the acrylic resin composition obtained in Examples and Comparative Examples were subjected to a cylinder and T-die (width 150 mm) temperature of 245 ° C. and a lip gap of 0 by a single-screw extruder (Optical Control System model FS-5). Extruded at .5 mm, sandwiched between cooling rolls at 80 ° C to form a film, picked up at 3.5 m / min, formed a film with a thickness of 60 μm, and visually checked the number of defects per ^{1 m 2 at three locations.} The measurements were taken and the average values were compared. The number of defects in the film was determined according to the following criteria.
<Criteria>
1 (Good): The ^{number of defective defects per 1m 2} is less than 10 2 (Normal): The ^{number of defective defects per 1m 2} is 10 or more and less than 50 3 (Bad): The number of defective defects per ^{1m 2 is 50} that's all

[Silver streak]
For the pellets of the acrylic resin composition obtained in Examples and Comparative Examples, an injection molding machine (model IS-22PV manufactured by Toshiba Machine Co., Ltd.) was used, and a flat plate mold (molded product dimensions: 48 mm × 78 mm × 3 mm) was used. , Cylinder temperature 250 ° C, screw rotation speed 100 rpm, mold temperature 60 ° C, back pressure 10 kg / cm ² , injection time 20 seconds, injection speed 2.7 mm / sec, cooling time 30 seconds, with holding pressure (primary pressure 65 / 100 shots of injection molding were performed under the condition of a secondary pressure of 60 kg / cm ² ), and the surface of the molded product was visually observed to check for the presence or absence of silver streaks.
<Criteria>
1 (Good): Silver streak occurs 0 out of 100 2 (Normal): Silver streak occurs less than 5 out of 100 3 (Bad): Silver streak occurs 5 out of 100

[Die stain]
For the pellets of the acrylic resin composition obtained in Examples and Comparative Examples, an injection molding machine (model IS-22PV manufactured by Toshiba Machine Co., Ltd.) was used, and a flat plate mold (molded product dimensions: 48 mm × 78 mm × 3 mm) was used. , Cylinder temperature 250 ° C, screw rotation speed 100 rpm, mold temperature 60 ° C, back pressure 10 kg / cm ² , injection time 20 seconds, injection speed 2.7 mm / sec, cooling time 30 seconds, with holding pressure (primary pressure 65 / Under the condition of secondary pressure 60 kg / cm ² ), 700 shots of injection molding were performed, and the presence or absence of dirt on the mold was examined.
<Criteria>
1 (Good): No mold stain 2 (Normal): Mold stain is found in the range of less than 5% of the inner dimensions of the mold.
3 (bad): Mold stains are found in the range of 5% or more of the inner dimensions of the mold.

[Production Example 1: Production of Multilayer Polymer Particles with Three-Layer Structure]
[Synthesis of layer (first layer) containing crosslinked hard body]
A reactor equipped with a stirrer, a thermometer, a nitrogen gas introduction pipe, a monomer introduction pipe and a reflux condenser was prepared. In the reactor, 733 parts by mass of ion-exchanged water, 0.09 parts by mass of polyoxyethylene (EO = 3) tridecyl ether sodium acetate, and 0.5 parts by mass of sodium carbonate were charged. The inside of the reactor was sufficiently replaced with nitrogen gas. Then, the internal temperature was adjusted to 80 ° C.
Separately, 175 parts by mass of a monomer mixture having the composition of the first layer shown in Table 1 was prepared. The first layer raw material was prepared by dissolving 1.23 parts by mass of polyoxyethylene (EO = 3) tridecyl ether sodium acetate as an emulsifier in the monomer mixture. 0.17 parts by mass of potassium persulfate was charged into the reactor, and then the first layer raw material was continuously added dropwise over 45 minutes. After completion of the dropping, the polymerization reaction was further carried out for 40 minutes. From the above, an emulsion containing the polymer component of the first layer was obtained.

[Synthesis of layer (second layer) containing crosslinked rubber (I)]
Next, 0.225 parts by mass of potassium persulfate was charged into the reactor. Separately, 225 parts by mass of a monomer mixture having the composition of the second layer shown in Table 1 was prepared. A second layer raw material was prepared by dissolving 0.59 parts by mass of polyoxyethylene (EO = 3) tridecyl ether sodium acetate as an emulsifier in the monomer mixture. The emulsion obtained in the above step was stirred, and the second layer raw material was continuously added dropwise over 60 minutes. After completion of the dropping, a polymerization reaction was further carried out for 90 minutes to obtain an emulsion containing the crosslinked rubber (I-1).

[Synthesis of layer (third layer) containing thermoplastic resin (II)]
Next, 0.289 parts by mass of potassium persulfate was charged into the reactor. Separately, 289 parts by mass of a monomer mixture having the composition of the third layer shown in Table 1 was prepared. The emulsion containing the crosslinked rubber (I-1) was stirred, and the monomer mixture having the composition of the third layer was continuously added dropwise over 75 minutes. After completion of the dropping, the polymerization reaction was further carried out for 115 minutes.
By the above operation, an emulsion containing multilayer structure polymer particles in which a thermoplastic resin is graft-polymerized on a crosslinked rubber was obtained. By freezing the emulsion, the multilayer structure polymer particles were solidified. Next, the coagulated product was washed with water and dried to obtain a powder of the multilayer structure polymer particles.

[Production Examples 2-4: Production of Multilayer Polymer Particles]
Emulsions containing the crosslinked rubber polymer were obtained up to the first layer and the second layer in the same manner as in Example 1.
Next, 0.289 parts by mass of potassium persulfate was charged into the reactor. Separately, 289 parts by mass of a monomer mixture having the composition of the third layer shown in Table 1 was prepared. The emulsion containing the crosslinked rubber (I-1) was stirred, and the monomer mixture having the composition of the third layer was continuously added dropwise over 75 minutes. After completion of the dropping, the polymerization reaction was further carried out for 115 minutes.
By the above operation, an emulsion containing multilayer structure polymer particles in which a thermoplastic resin is graft-polymerized on a crosslinked rubber was obtained. By freezing the emulsion, the multilayer structure polymer particles were solidified. Next, the coagulated product was washed with water and dried to obtain a powder of the multilayer structure polymer particles.

[Production Example 5: Production of Multilayer Polymer Particles]
Emulsions containing the crosslinked rubber polymer were obtained up to the first layer and the second layer in the same manner as in Example 1.
Next, 0.2 parts by mass of potassium persulfate was charged into the reactor. Separately, 220 parts by mass of a monomer mixture having the composition of the third layer shown in Table 1 was prepared. The emulsion containing the crosslinked rubber (I-1) was stirred, and the monomer mixture having the composition of the third layer was continuously added dropwise over 50 minutes. After completion of the dropping, the polymerization reaction was further carried out for 80 minutes.
By the above operation, an emulsion containing multilayer structure polymer particles in which a thermoplastic resin is graft-polymerized on a crosslinked rubber was obtained. By freezing the emulsion, the multilayer structure polymer particles were solidified. Next, the coagulated product was washed with water and dried to obtain a powder of the multilayer structure polymer particles.

[Production Example 6: Production of Multilayer Polymer Particles]
Emulsions containing the crosslinked rubber polymer were obtained up to the first layer and the second layer in the same manner as in Example 1.
Next, 0.289 parts by mass of potassium persulfate was charged into the reactor. Separately, 289 parts by mass of a monomer mixture composed of the composition of the third layer shown in Table 1 was prepared. The emulsion containing the crosslinked rubber (I-1) was stirred, and the monomer mixture having the composition of the third layer was continuously added dropwise over 75 minutes. After completion of the dropping, the polymerization reaction was further carried out for 115 minutes.
By the above operation, an emulsion containing multilayer structure polymer particles in which a thermoplastic resin is graft-polymerized on a crosslinked rubber was obtained. By freezing the emulsion, the multilayer structure polymer particles were solidified. Next, the coagulated product was washed with water and dried to obtain a powder of the multilayer structure polymer particles.

[Production Example 7: Production of Multilayer Polymer Particles]
Emulsions containing the crosslinked rubber polymer were obtained up to the first layer and the second layer in the same manner as in Example 1.
Next, 0.1 part by mass of potassium persulfate was charged into the reactor. Separately, 100 parts by mass of a monomer mixture composed of the composition of the third layer shown in Table 1 was prepared. The emulsion containing the crosslinked rubber (I-1) was stirred, and the monomer mixture having the composition of the third layer was continuously added dropwise over 25 minutes. After completion of the dropping, the polymerization reaction was further carried out for 45 minutes.
By the above operation, an emulsion containing multilayer structure polymer particles in which a thermoplastic resin is graft-polymerized on a crosslinked rubber was obtained. By freezing the emulsion, the multilayer structure polymer particles were solidified. Next, the coagulated product was washed with water and dried to obtain a powder of the multilayer structure polymer particles.

In Table 1, V1-1 is the content (mass part) of the crosslinked hard body in the inner layer of the multilayer structure polymer particles, and V1-2 is the content (mass) of the crosslinked rubber (I) in the inner layer of the multilayer structure polymer particles. Part), V2 represents the content (mass part) of the outer layer of the multilayer structure polymer particles.

[Manufacturing Example 8: Production of (Meta) Acrylic Resin [Thermoplastic Resin (III)]]
99.3 parts by mass of methyl methacrylate and 0.7 parts by mass of methyl acrylate, a polymerization initiator [2,2'-azobis (2-methylpropionitrile), hydrogen extraction capacity: 1%, 1 hour half-life temperature: 83 ° C. ] 0.008 parts by mass and 0.26 parts by mass of the chain transfer agent (n-octyl mercaptan) were added and dissolved to obtain 3000 kg of a raw material solution.
100 parts by mass of ion-exchanged water, 0.03 parts by mass of sodium sulfate, and 0.45 parts by mass of suspension dispersant were mixed to obtain 6000 kg of a mixed solution. The mixed solution and the raw material solution (total of 9000 kg) were charged in a pressure-resistant polymerization tank, and the polymerization reaction was started at a temperature of 70 ° C. while stirring in a nitrogen atmosphere. After 3 hours from the start of the polymerization reaction, the temperature was raised to 90 ° C. and stirring was continued for 1 hour to obtain a liquid in which the bead-like copolymer was dispersed. Although some polymer adhered to the wall surface of the polymerization tank or the stirring blade, the polymerization reaction proceeded smoothly without foaming.
The obtained copolymer dispersion was washed with an appropriate amount of ion-exchanged water, the beaded copolymer was taken out by a bucket centrifuge, and dried in a hot air dryer at 80 ° C. for 12 hours to form beads ( Meta) Acrylic resin was obtained.
The obtained (meth) acrylic resin has a methyl methacrylate unit content of 99.3% by mass, a methyl acrylate unit content of 0.7% by mass, a number average molecular weight of 46,000, and a glass transition temperature of 120. It was ° C.

[Example 1]
Biaxial kneading of 41 mmφ while controlling 72 parts by mass of the (meth) acrylic resin produced as the thermoplastic resin (III) in Production Example 8 and 28 parts by mass of the multilayer structure polymer particles produced in Production Example 1 with a weight feeder. It was put into the hopper of an extruder (manufactured by Toshiba Machine Co., Ltd., TEM41-SS), the temperature under the hopper was set to 150 ° C, and the barrel temperature was set to 230 ° C, respectively, and the (meth) acrylic resin composition was made into a strand shape. Pellets of the (meth) acrylic resin composition were produced by extruding and cutting with a pelletizer.
Table 2 shows the evaluation results of the obtained (meth) acrylic resin composition, the (meth) acrylic resin film, and the molded product.

[Examples 2 to 6, Comparative Example 1]
Pellets of the (meth) acrylic resin composition were produced in the same manner as in Example 1 except that the composition ratios of the multilayer structure polymer particles and the thermoplastic resin (III) were changed as shown in Table 2. ..
Table 2 shows the evaluation results of the obtained (meth) acrylic resin composition, the (meth) acrylic resin film, and the molded product.

[Evaluation results]
In Examples 1 to 6 using the multilayer structure polymer particles having a weight loss rate of 5% or less at 200 ° C. to 280 ° C., the defects of the film, the appearance of the molded product (generation of silver streaks), and the stain on the mold were observed. All the evaluations were good results. On the other hand, Comparative Example 1 using the multilayer structure polymer particles having a high weight loss rate of 11.0% at 200 ° C. to 280 ° C. shows the defects of the film, the appearance of the molded product (generation of silver streaks), and the stain on the mold. All of the evaluations were bad.

Claims (15)

Multilayered polymer particles having an inner layer including a crosslinked rubber (I) layer and an outer layer containing a thermoplastic resin (II) graft-bonded to the inner layer.
Multilayered polymer particles having a weight loss rate of 5% or less at 200 ° C. to 280 ° C. when the temperature is raised from 200 ° C. to 1 ° C./min under a nitrogen atmosphere by thermogravimetric analysis. The multilayer structure polymer particles according to claim 1, wherein the mass ratio [V2 / V1] is 0.30 or more when the mass of the inner layer is V1 and the mass of the outer layer is V2. The multilayer structure polymer particles according to claim 1 or 2, wherein the acetone solubility is 45% by mass or less. The multilayer structure polymer particles according to any one of claims 1 to 3, wherein the median diameter measured by a laser diffraction-scattering method is 80 to 500 nm. The multilayer structure polymer particle according to any one of claims 1 to 4, wherein the thermoplastic resin (II) has a number average molecular weight of 20,000 to 50,000. The crosslinked rubber (I) has an acrylic acid ester unit of 50.0 to 99.0% by mass, a polyfunctional monomer unit of 0.01 to 5.0% by mass, and other unsaturated products copolymerizable with these. Contains 0.01-49.0% by mass of monomeric units
Claimed that the thermoplastic resin (II) contains 40.0 to 99.0% by mass of a methacrylic acid ester unit and 0.1 to 60.0% by mass of another unsaturated monomer unit copolymerizable therewith. Item 2. The multilayer structure polymer particle according to any one of Items 1 to 5. A thermoplastic resin composition containing 5 to 95% by mass of the thermoplastic resin (III) and 5 to 95% by mass of the multilayer structure polymer particles according to any one of claims 1 to 6. The thermoplastic resin composition according to claim 7, wherein the thermoplastic resin (III) is an amorphous resin. The thermoplastic resin composition according to claim 7 or 8, wherein the thermoplastic resin (III) has a glass transition temperature of 50 to 170 ° C. The thermoplastic resin composition according to any one of claims 7 to 9, wherein the thermoplastic resin (III) has a number average molecular weight of 10,000 to 500,000. The thermoplastic resin composition according to any one of claims 7 to 10, wherein the thermoplastic resin (III) is a (meth) acrylic resin. The thermoplastic resin composition according to claim 11, wherein the (meth) acrylic resin contains 80.0 to 99.9% by mass of a methacrylic acid ester unit and 0.1 to 20.0% by mass of an acrylic acid ester unit. .. A molded product made of the thermoplastic resin composition according to any one of claims 7 to 12. A film comprising the thermoplastic resin composition according to any one of claims 7 to 12. A molded product containing the multilayer structure polymer particles according to any one of claims 1 to 6.

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