WO2020195798A1

WO2020195798A1 - Thermoplastic resin composition and molded article

Info

Publication number: WO2020195798A1
Application number: PCT/JP2020/010321
Authority: WO
Inventors: 亜里紗園山; 友也真部; 大輝芳村
Original assignee: 株式会社カネカ
Priority date: 2019-03-26
Filing date: 2020-03-10
Publication date: 2020-10-01
Also published as: JPWO2020195798A1; CN113614178B; CN113614178A

Abstract

A thermoplastic resin composition that contains: a particulate graft copolymer that is formed from a seed, a core layer, and a shell layer; and a matrix resin. The matrix resin includes an acrylonitrile-styrene resin. The difference between the refractive index of the seed and the refractive index of the matrix resin is at least 0.07. The core layer comprises a polymer that has a cross-linked structure and is a polymer of a monomer component that includes an acrylic acid ester. The graft copolymer satisfies the following expressions. In the expressions, r1 is the radius (nm) of the seed, and r2 is the radius (nm) of a particle formed from the seed and the core layer. 300≤2×r2≤700; 40≤r2-r1≤210.

Description

Thermoplastic resin composition and molded article

The present invention relates to a thermoplastic resin composition and a molded product.

Conventionally, as a technique for improving the impact resistance of a thermoplastic resin, a method of blending a graft copolymer containing a rubber component into the thermoplastic resin has been known.

However, when a molded product is produced from a thermoplastic resin composition containing such a rubber-containing graft copolymer, the color tone of the molded product may change depending on the graft copolymer, resulting in a decrease in color development.

In order to obtain a thermoplastic resin composition having good color development while improving impact resistance, a method of reducing the difference in refractive index between the matrix resin and the graft copolymer is common. Methyl methacrylate-butadiene-styrene resin (MBS) is widely used as a suitable graft copolymer in that case. However, since MBS contains butadiene rubber, it is susceptible to deterioration by ultraviolet rays and the like, resulting in deterioration of impact resistance and color development, and its use tends to be limited to indoor use.

A graft copolymer containing acrylic rubber is also known instead of butadiene rubber having such restrictions.

Patent Document 1 discloses an ASA (acrylonitrile-acrylate-styrene) -based graft copolymer, which is a graft copolymer containing acrylic rubber, and a resin composition containing a matrix resin. Here, the difference between the refractive index of the seed and shell layer of the graft copolymer composed of the seed, core layer and shell layer and the refractive index of the matrix resin is small so as to be less than 0.035. It is described that the color development is improved by reducing the thickness (r2-r1) of the core having a large difference in refractive index from the matrix resin while selecting the monomer composition of the layer.

On the other hand, it is known that a styrene-acrylonitrile copolymer or an alloy of this and a polycarbonate resin is used as a thermoplastic resin used for a molded product used for automobile interior / exterior applications.

Special Table 2014-527570

According to the method described in Patent Document 1, since it is necessary to reduce the difference in refractive index between the seed and the matrix resin, the monomer composition of the seed is limited. However, the seed composition described in Patent Document 1 has a drawback that the polymerization rate is slow and the productivity is lowered particularly when a seed having a large particle size is to be produced. In addition, since it is necessary to reduce the thickness of the core layer having a function of ensuring impact resistance, the impact resistance tends to decrease.

In view of the above situation, the present invention has excellent impact resistance in a thermoplastic resin composition containing a graft copolymer and a matrix resin without reducing the difference in refractive index between the seed of the graft copolymer and the matrix resin. It is an object of the present invention to provide a thermoplastic resin composition exhibiting color development.

The present inventors are graft copolymers capable of exhibiting excellent impact resistance and color development by blending with a matrix resin containing a styrene-acrylonitrile copolymer widely used in automobile interior / exterior applications. It was investigated. As a result, in the graft copolymer composed of the seed, the core layer and the shell layer, the diameter of the particles composed of the seed and the core layer and the thickness of the core layer are set in specific ranges to set the seed and the matrix. It has been found that excellent impact resistance and color development can be exhibited without adopting a seed monomer composition that reduces the difference in refractive index of the resin.

That is, the present invention contains heat containing a seed, a particulate graft copolymer composed of a core layer formed on the surface of the seed, and a shell layer formed on the surface of the core layer, and a matrix resin. A plastic resin composition, wherein the matrix resin contains an acrylonitrile-styrene resin, and the seed is at least one selected from the group consisting of (meth) acrylic acid esters, aromatic vinyl compounds, and vinyl cyanide compounds. It is composed of a polymer of a monomer component containing a seed, the difference between the refractive index of the seed and the refractive index of the matrix resin is 0.07 or more, and the core layer is a monomer component containing at least one acrylonitrile ester. The shell layer is a polymer containing at least one selected from the group consisting of a (meth) acrylic acid ester, an aromatic vinyl compound, and a vinyl cyanide compound. The graft copolymer, which comprises a polymer of components, relates to a thermoplastic resin composition satisfying the following formulas (1) and (2).
300 ≦ 2xr2 ≦ 700 (1)
40 ≦ r2-r1 ≦ 210 (2)
(In the formula, r1 represents the radius (nm) of the seed, and r2 represents the radius (nm) of the particles composed of the seed and the core layer.)

Preferably, the weight ratio of the core layer in the graft copolymer is 83% by weight or less. Preferably, the seed comprises a polymer obtained by polymerizing 80 to 100% by weight of a (meth) acrylic acid ester and 0 to 20% by weight of an aromatic vinyl compound. Preferably, the (meth) acrylic acid ester in the seed comprises an alkyl methacrylate ester. Preferably, the polymer constituting the seed has a crosslinked structure. Preferably, the core layer is composed of two or more different layers. Preferably, the shell layer comprises a polymer obtained by polymerizing at least an aromatic vinyl compound and a vinyl cyanide compound. Preferably, the weight ratio of the graft copolymer to the total of the matrix resin and the graft copolymer is 3 to 50% by weight.

Preferably, the matrix resin further contains a polycarbonate resin. Preferably, the weight ratio of the acrylonitrile-styrene resin to the polycarbonate resin is 25:75 to 5:95. Preferably, the weight ratio of the graft copolymer to the total of the matrix resin and the graft copolymer is 3 to 15% by weight.

The present invention also relates to a molded product obtained by molding the thermoplastic resin composition.

According to the present invention, in a thermoplastic resin composition containing a graft copolymer and a matrix resin, excellent impact resistance and color development can be obtained without reducing the difference in refractive index between the seed of the graft copolymer and the matrix resin. The thermoplastic resin composition shown can be provided. In addition, the thermoplastic resin composition according to the preferred embodiment of the present invention is excellent in fluidity at the time of melting, and therefore can be easily used for thin-wall molding and large-sized molded products.

An embodiment of the present invention will be described in detail below.

(Thermoplastic resin composition)
The thermoplastic resin composition of the present invention contains a matrix resin and a graft copolymer as an impact resistance improving agent. The ratio of the matrix resin and the graft copolymer used is not particularly limited, and can be appropriately set according to the composition of the matrix resin. From the viewpoint of ensuring good color development while exhibiting excellent impact resistance, the weight ratio of the graft copolymer to the total of the matrix resin and the graft copolymer is usually 1 to 60% by weight. It may be a range. More specifically, when the matrix resin is composed only of acrylonitrile-styrene resin, the weight ratio is preferably 5 to 55% by weight, more preferably 10 to 50% by weight, and further preferably 15 to 45% by weight. preferable. When the matrix resin is composed of a mixture of acrylonitrile-styrene resin and polycarbonate resin, the weight ratio is preferably 2 to 20% by weight, more preferably 3 to 19% by weight, still more preferably 4 to 18% by weight. 5 to 17% by weight is particularly preferable.

(Matrix resin)
The matrix resin in the present invention contains at least an acrylonitrile-styrene resin. The acrylonitrile-styrene resin (abbreviated as AS resin, also known as SAN plastic) is a copolymer of acrylonitrile and styrene, and is a resin known as a thermoplastic resin having excellent transparency and heat resistance.

The matrix resin in the present invention may consist only of acrylonitrile-styrene resin, or may further contain a thermoplastic resin other than acrylonitrile-styrene resin.

The thermoplastic resin other than the acrylonitrile-styrene resin is not particularly limited, and examples thereof include polycarbonate resin, polyamide resin, acrylic resin, styrene resin, and polyphenylene ether resin. Only one kind of these may be used, or two or more kinds may be used in combination.

Of these, polycarbonate resin is preferable. The polycarbonate resin is preferably obtained by reacting a divalent or higher phenolic compound with a carbonic acid diester compound such as phosgene or diphenyl carbonate.

The divalent or higher valent phenolic compound is not particularly limited, but for example, 2,2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A), bis (4-hydroxyphenyl) methane, and bis (4-hydroxyphenyl). ) Phenylmethane, bis (4-hydroxyphenyl) naphthylmethane, bis (4-hydroxyphenyl)-(4-isopropylphenyl) methane, bis (3,5-dichloro-4-hydroxyphenyl) methane, bis (3,5) -Dimethyl-4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 1-naphthyl-1,1-bis (4-hydroxyphenyl) ethane, 1-phenyl-1,1-bis ( 4-Hydroxyphenyl) ethane, 1,2-bis (4-hydroxyphenyl) ethane, 2-methyl-1,1-bis (4-hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl-4) -Hydroxyphenyl) propane, 1-ethyl-1,1-bis (4-hydroxyphenyl) propane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane, 2,2-bis (3, 5-Dibromo-4-hydroxyphenyl) propane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3-Fluoro-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) butane, 1,4-bis (4-hydroxyphenyl) butane , 2,2-bis (4-hydroxyphenyl) pentane, 4-methyl-2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) hexane, 4,4-bis ( 4-Hydroxyphenyl) heptane, 2,2-bis (4-hydroxyphenyl) nonane, 1,10-bis (4-hydroxyphenyl) decane, 1,1-bis (4-hydroxyphenyl) -3,3,5 -Trimethylcyclohexane, dihydroxydiarylalkanes such as 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane, 1,1-bis (4-hydroxyphenyl) cyclohexane , 1,1-bis (3,5-dichloro-4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) cyclodecane and other dihydroxydi Arylcycloalkans, dihydroxydiarylsulfones such as bis (4-hydroxyphenyl) sulfone, bis (3,5-dimethyl-4-hydroxyphenyl) sulfone, bis (3-chloro-4-hydroxyphenyl) sulfone, bis ( Dihydroxyaryl ethers such as 4-hydroxyphenyl) ether, bis (3,5-dimethyl-4-hydroxyphenyl) ether, 4,4'-dihydroxybenzophenone, 3,3', 5,5'-tetramethyl-4 , Dihydroxydiarylketones such as 4'-dihydroxybenzophenone, bis (4-hydroxyphenyl) sulfide, bis (3-methyl-4-hydroxyphenyl) sulfide, bis (3,5-dimethyl-4-hydroxyphenyl) sulfide, etc. Dihydroxydiarylsulfides, dihydroxydiaryl sulfoxides such as bis (4-hydroxyphenyl) sulfoxides, dihydroxydiphenyls such as 4,4'-dihydroxydiphenyl, dihydroxyaryls such as 9,9-bis (4-hydroxyphenyl) fluorene. Examples include sulfones. In addition to the above dihydric phenol compounds, dihydroxybenzenes such as hydroquinone, resorcinol and methylhydroquinone, and dihydroxynaphthalene such as 1,5-dihydroxynaphthalene and 2,6-dihydroxynaphthalene are used as divalent phenolic compounds. it can.

Phenolic compounds of trivalent or higher can also be used as long as the obtained polycarbonate resin maintains thermoplasticity. Examples of the trivalent or higher valent phenolic compound include 2,4,4'-trihydroxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 2,4,4'-trihydroxyphenyl ether, 2,2', 4,4'-tetrahydroxyphenyl ether, 2,4,4'-trihydroxydiphenyl-2-propane, 2,2'-bis (2,4-dihydroxy) propane, 2,2', 4,4'-Tetrahydroxydiphenylmethane, 2,4,4'-trihydroxydiphenylmethane, 1- [α-methyl-α- (4'-dihydroxyphenyl) ethyl] -3- [α', α'-bis ( 4 "-Hydroxyphenyl) ethyl] benzene, 1- [α-methyl-α- (4'-dihydroxyphenyl) ethyl] -4- [α', α'-bis (4" -hydroxyphenyl) ethyl] benzene, α, α', α "-tris (4-hydroxyphenyl) -1,3,5-triisopropylbenzene, 2,6-bis (2-hydroxy-5'-methylbenzyl) -4-methylphenol, 4, 6-dimethyl-2,4,6-tris (4'-hydroxyphenyl) -2-heptene, 4,6-dimethyl-2,4,6-tris (4'-hydroxyphenyl) -2-heptane, 1, 3,5-Tris (4'-hydroxyphenyl) benzene, 1,1,1-Tris (4-hydroxyphenyl) ethane, 2,2-bis [4,4-bis (4'-hydroxyphenyl) cyclohexyl] propane , 2,6-bis (2'-hydroxy-5'-isopropylbenzyl) -4-isopropylphenol, bis [2-hydroxy-3- (2'-hydroxy-5'-methylbenzyl) -5-methylphenyl] Methan, bis [2-hydroxy-3- (2'-hydroxy-5'-isopropylbenzyl) -5-methylphenyl] methane, tetrakis (4-hydroxyphenyl) methane, tris (4-hydroxyphenyl) phenylmethane, 2 ', 4', 7-trihydroxyflaban, 2,4,4-trimethyl-2', 4', 7-trihydroxyflavan, 1,3-bis (2', 4'-dihydroxyphenylisopropyl) benzene, tris Examples thereof include (4'-hydroxyphenyl) -amyl-s-triazine.

These divalent or higher valent phenolic compounds may be used alone or in combination of two or more.

If necessary, the polycarbonate resin can contain, if necessary, a component for making a branched polycarbonate resin in addition to a phenolic compound having a valence of 3 or more, as long as the thermoplasticity is not impaired. Examples of the component (branching agent) other than the trivalent or higher valent phenolic compound used to obtain the branched polycarbonate resin include fluoroglucin, merit acid, trimellitic acid, trimellitic acid chloride, trimellitic anhydride, and erosion. Acid, n-propyl gallate, protocatechuic acid, pyromellitic acid, pyromellitic dianhydride, α-resorcinic acid, β-resorcinic acid, resorcinaldehyde, trimethyl chloride, isatinbis (o-cresol), trimethyltrichloride, 4 -Chloroformylphthalic anhydride, benzophenone tetracarboxylic acid and the like can be mentioned.

In addition to this, as the copolymerization component of the polycarbonate resin, a linear aliphatic divalent carboxylic acid such as adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and decandicarboxylic acid may be used.

As a component of the polycarbonate resin, various known substances used as a terminal terminator during polymerization can be used, if necessary, as long as the effects of the present invention are not impaired. Specific examples thereof include monovalent phenolic compounds such as phenol, p-cresol, pt-butylphenol, pt-octylphenol, p-cumylphenol, bromophenol, tribromophenol and nonylphenol.

Examples of the carbonic acid diester compound used as a raw material for the polycarbonate resin include diaryl carbonates such as diphenyl carbonate and dialkyl carbonates such as dimethyl carbonate and diethyl carbonate.

Preferred specific examples of the polycarbonate resin include, for example, a polycarbonate resin obtained by an interfacial polycondensation method in which bisphenol A and phosgene are reacted, a polycarbonate resin obtained by a melt polymerization method in which bisphenol A and diphenyl carbonate are reacted, and the like. ..

A particularly preferable matrix resin in the present invention is a mixture of acrylonitrile-styrene resin and polycarbonate resin. The ratio of the acrylonitrile-styrene resin to the polycarbonate resin in the mixture is not particularly limited and can be appropriately set by those skilled in the art, but the weight ratio of the acrylonitrile-styrene resin: polycarbonate resin is 50:50 to 1:99. It is preferable, 40:60 to 2:98 is more preferable, and 30:70 to 3:97 is even more preferable. In particular, 25:75 to 5:95 is most preferable because excellent impact resistance can be obtained.

(Graft copolymer)
The graft copolymer in the present invention is in the form of particles composed of a seed, a core layer formed on the surface of the seed, and a shell layer formed on the surface of the core layer.

(seed)
The seed is a small particle existing inside the particles constituting the graft copolymer, and at least one selected from the group consisting of a (meth) acrylic acid ester, an aromatic vinyl compound, and a vinyl cyanide compound. It is composed of a polymer of the monomer components contained.

The (meth) acrylic acid ester is not particularly limited, and for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic. (Meta) acrylic acid alkyl esters such as octyl acid, dodecyl (meth) acrylic acid, stearyl (meth) acrylic acid, behenyl (meth) acrylic acid; phenoxyethyl (meth) acrylic acid, benzyl (meth) acrylic acid, etc. Arocyclic ring-containing (meth) acrylates; hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate; glycidyl such as glycidyl (meth) acrylate and glycidylalkyl (meth) acrylate. (Meta) acrylates; Examples thereof include alkoxyalkyl (meth) acrylates. In the present application, (meth) acrylic is a collective description of acrylic and methacrylic.

The aromatic vinyl compound is not particularly limited, and examples thereof include styrene, α-methylstyrene, monochlorostyrene, and dichlorostyrene.

The vinyl cyanide compound is not particularly limited, and examples thereof include acrylonitrile and methacrylonitrile.

In addition to these, vinyl carboxylic acids such as acrylic acid and methacrylic acid; vinyl halides such as vinyl chloride, vinyl bromide and chloroprene; vinyl acetate; alkenes such as ethylene, propylene, butylene and isobutylene are used in combination. May be good.

The present invention can exhibit good color development in a thermoplastic resin containing a graft copolymer, but it is not necessary to adjust so that the difference between the refractive index of the seed and the refractive index of the matrix resin becomes small. , The difference in refractive index is 0.07 or more. Therefore, as described in Patent Document 1, it is not necessary to select the monomer composition of the seed so that the difference in refractive index is less than 0.035. In particular, the styrene-based monomer composition disclosed in Patent Document 1 has a problem that the polymerization rate for forming seeds is slow and the productivity is lowered. However, in the present invention, it is not necessary to select the monomer composition of the seed disclosed in Patent Document 1, and the problem of such a decrease in productivity can be avoided. Further, if the difference in refractive index is less than 0.07, the impact resistance, particularly the impact resistance at a low temperature, is not sufficient. The difference in refractive index is preferably 0.08 or more, more preferably 0.085 or more, and further preferably 0.09 or more. The upper limit of the refractive index difference is not particularly limited, but may be, for example, 0.15 or less, 0.13 or less, or 0.11 or less.

The refractive index of the seed is the refractive index of the monomer forming the seed. When the seed is formed from two or more kinds of monomers, the refractive index of the seed is calculated from the refractive index of each monomer and the weight ratio of each monomer to the whole seed. The refractive index of the matrix resin was measured according to the JIS K7142 standard. When the matrix resin is a mixture, the refractive index of the matrix resin is calculated from the refractive index of each resin and the weight ratio of each resin in the entire matrix resin.

According to a preferred embodiment of the present invention, the polymer constituting the seed is a polymer mainly composed of (meth) acrylic acid ester, and specifically, 80 to 100% by weight of (meth) acrylic acid ester and It is a polymer obtained by polymerizing 0 to 20% by weight of an aromatic vinyl compound. A seed composed of a polymer having such a monomer composition can easily achieve a refractive index difference of 0.07 or more between the seed and the matrix resin described above, and has impact resistance, particularly impact resistance at low temperatures. Can be improved. Further, since the seed can be polymerized at a higher speed than the styrene-based seed described in Patent Document 1, productivity can be improved. The ratio of each of the monomers is the weight ratio of each monomer to the total polymer constituting the seed. From the viewpoint of higher impact resistance and productivity, preferably (meth) acrylic acid ester is 85% by weight or more, aromatic vinyl compound is 15% by weight or less, and more preferably (meth) acrylic acid ester is 90% by weight. % Or more, the aromatic vinyl compound is 10% by weight or less, more preferably the (meth) acrylic acid ester is 95% by weight or more, and the aromatic vinyl compound is 5% by weight or less. The proportion of the aromatic vinyl compound may be 0% by weight.

As the (meth) acrylic acid ester used in the seed, it is preferable to use an alkyl methacrylate ester. By using the methacrylic acid alkyl ester in the seed, the seed can be composed of a hard polymer, which is advantageous for improving the color development property. Of these, methyl methacrylate is particularly preferable.

The (meth) acrylic acid ester used in the seed may be only one or more kinds of methacrylic acid alkyl esters, or one or more kinds of methacrylic acid alkyl esters and one or more kinds. Acrylic acid alkyl ester of the above may be used in combination. The latter is preferable from the viewpoint of thermal stability described later. It is particularly preferable to use butyl acrylate as the acrylic acid alkyl ester.

According to a particularly preferred embodiment of the present invention, the monomer composition of the polymer constituting the seed is 40 to 100% by weight of the methacrylic acid alkyl ester, 0 to 35% by weight of the acrylic acid alkyl ester, and 0 to 10% by weight of the aromatic vinyl compound. % And 0 to 15% of other monomers having a copolymerizable double bond, preferably 40 to 99.9% by weight of alkyl methacrylate ester and 0.1 to 35% by weight of alkyl acrylate ester. , 0 to 10% by weight of the aromatic vinyl compound, and 0 to 15% by weight of the other monomer having a copolymerizable double bond, more preferably 40 to 99.8% by weight of the alkyl methacrylate ester, acrylic. More preferably, it is 0.1 to 35% by weight of an acid alkyl ester, 0.1 to 10% by weight of an aromatic vinyl compound, and 0 to 15% by weight of another monomer having a copolymerizable double bond. Acid alkyl ester 51-96.9% by weight, acrylic acid alkyl ester 3.1-29% by weight, aromatic vinyl compound 0-10% by weight, and 0-10% of other monomers having copolymerizable double bonds. It is even more preferably by weight%. Within this range, the thermal stability of the graft copolymer can be increased, and it can withstand high-temperature molding. Specifically, the methacrylic acid alkyl ester, which is the main component, easily undergoes zip depolymerization during high-temperature molding and is easily thermally decomposed. However, by containing the acrylic acid alkyl ester and the aromatic vinyl compound in the above range, zipping is performed. Depolymerization can be easily suppressed and thermal stability can be improved.

The seed may be composed of a polymer having no crosslinked structure introduced therein, but is preferably composed of a polymer having a crosslinked structure. As a result, the seed can be composed of a hard polymer, which is advantageous for improving the color development property. The method for introducing the crosslinked structure is not particularly limited, but for example, when the monomer component is polymerized to synthesize a seed, a crosslinked monomer such as a polyfunctional monomer or a mercapto group-containing compound may be used.

Examples of the polyfunctional monomer include allylalkyl (meth) acrylates such as allyl (meth) acrylate and allylalkyl (meth) acrylate; allyloxyalkyl (meth) acrylates; (poly) ethylene glycol di (meth) acrylate. Polyfunctional (meth) having two or more (meth) acrylic groups such as butanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and tetraethylene glycol di (meth) acrylate. Acrylate; Examples thereof include diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, and divinylbenzene. Allyl methacrylate, triallyl isocyanurate, butanediol di (meth) acrylate, and divinylbenzene are preferable, and allyl methacrylate is particularly preferable.

The ratio of the polyfunctional monomer used is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the total of the monomer components (monomers other than the polyfunctional monomer) constituting the polymer of the seed. It is more preferably 0.1 to 8 parts by weight, still more preferably 0.5 to 6 parts by weight.

The weight ratio of the seed in the graft copolymer is preferably 3 to 40% by weight, more preferably 4 to 30% by weight, still more preferably 5 to 25% by weight, from the viewpoint of color development. Further, from the viewpoint of imparting impact resistance, 20% by weight or less is more preferable, 15% by weight or less is more preferable, and 10% by weight or less is particularly preferable.

(Core layer)
The core layer is a polymer layer formed on the surface of seed particles, is a polymer of a monomer component containing at least one acrylic acid ester, and is composed of a polymer having a crosslinked structure. Is. This core layer mainly has a function of imparting impact resistance to the matrix resin. The polymer constituting the core layer is preferably grafted to the polymer constituting the seed. The core layer does not cover the entire surface of the seed particles, but may cover at least a part of the surface of the seed particles.

The polymer constituting the core layer is a polymer of monomer components containing an acrylic acid ester. Specific examples of acrylic acid esters include those listed with respect to seeds. In particular, an acrylic acid alkyl ester is preferable, and butyl acrylate is more preferable. Further, a monomer other than the acrylic acid ester may be used in combination, or may not be used in combination. As the other monomer, it can be appropriately selected from the monomers listed for the seed. The weight ratio of the acrylic acid ester to the entire monomer component of the core layer is preferably 50% by weight or more, more preferably 70% by weight or more, further preferably 80% by weight or more, and particularly preferably 90% by weight or more.

The polymer constituting the core layer has a crosslinked structure. The method for introducing the crosslinked structure and specific examples of the polyfunctional monomer are the same as those described above for the seed. The total usage ratio of the polyfunctional monomer in the core layer is preferably 0.01 to 10% by weight with respect to a total of 100 parts by weight of the monomer components (monomers other than the polyfunctional monomer) constituting the polymer of the core layer. It is, more preferably 0.05 to 5 parts by weight, still more preferably 0.1 to 3 parts by weight.

Further, the core layer may be a single layer, but may be a layer composed of two or more layers. According to a preferred embodiment of the present invention, the core layer is composed of two or more layers having different compositions from each other. In this case, the core layer is composed of a first core layer formed on the surface of the seed and a second core layer formed on the surface of the first core layer. The composition of the first core layer and the second core layer can be appropriately selected from the above.

According to a preferred embodiment, the weight ratio of the second core layer to the entire core layer is preferably 1 to 50% by weight, more preferably 2 to 30% by weight, still more preferably 3 to 10% by weight, and the second. The usage ratio of the polyfunctional monomer in the core layer is set higher than the usage ratio of the polyfunctional monomer in the first core layer (that is, the cross-linking density of the second core layer is higher than the cross-linking density of the first core layer. Set high). In such a core layer having a two-layer structure, impact resistance is mainly imparted by the first core layer located inside. On the other hand, the second core layer, which is located on the outside and is harder than the first core layer, regulates the formation of the free polymer, thereby suppressing the aggregation of the particles of the graft copolymer and the matrix resin and the graft co-weight. The compatibility of coalescence can be improved. As a result, the dispersibility of the graft copolymer in the matrix resin is improved, and as a result, the color development property and the impact resistance can be further improved.

Specifically, the ratio of the polyfunctional monomer used in the first core layer is preferably 100 parts by weight in total of the monomer components (monomers other than the polyfunctional monomer) constituting the polymer of the first core layer. Is 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, still more preferably 0.1 to 1 part by weight, and the ratio of the polyfunctional monomer used in the second core layer is , It is preferably 0.5 to 10 parts by weight, more preferably 1 to 5 parts by weight, based on a total of 100 parts by weight of the monomer components (monomers other than the polyfunctional monomer) constituting the polymer of the second core layer. It is a part, more preferably 1.5 to 4 parts by weight.

The weight ratio of the entire core layer to the graft copolymer is preferably 83% by weight or less from the viewpoint of color development. In this range, the color development property is more likely to be improved. It is more preferably 73% by weight or less, further preferably 63% by weight or less, still more preferably 53% by weight or less, and particularly preferably 50% by weight or less. From the viewpoint of imparting impact resistance, the lower limit of the weight ratio is preferably 20% by weight or more, more preferably 30% by weight or more, further preferably 35% by weight or more, still more preferably 40% by weight or more.

The graft copolymer of the present invention is characterized in that the diameter of the particles composed of the seed and the core layer and the thickness of the core layer each satisfy specific conditions. The diameter of the particles composed of the seed and the core layer is represented by the following formula (1), and the thickness of the core layer is represented by the following formula (2).
300 ≦ 2xr2 ≦ 700 (1)
40 ≦ r2-r1 ≦ 210 (2)

In each formula, r1 represents the radius (nm) of the seed. r2 represents the radius (nm) of the particles composed of the seed and the core layer (that is, the particles before the seed and the core layer are formed and the shell layer is formed). 2 × r1 and 2 × r2 are the latex states of the seeds or the latex states of the particles before the seed and core layers are formed and the shell layer is formed, respectively, and MICROTRAC manufactured by Nikkiso Co., Ltd. It can be measured as a volume average particle size (nm) using UPA150.

The above formula (1) defines that the diameter of the particles composed of the seed and the core layer (hereinafter, also referred to as the particle diameter) is 300 to 700 nm. If the diameter is less than 300 nm, the impact resistance, particularly the impact resistance at a low temperature, is not sufficient. The particle size is preferably 320 nm or more, more preferably 340 nm or more, further preferably 360 nm or more, particularly preferably 380 nm or more, and most preferably 400 nm or more. In the present invention, by making the particle diameter to the core layer relatively large in this way, the light scattering mechanism is changed from Rayleigh scattering to Mie scattering, and therefore, good color development is achieved despite the large particles. It was realized. Since the scattering mechanism is changed to Mie scattering in this way to achieve good color development, the influence of the difference in refractive index between the seed and the matrix resin on the color development is alleviated, and as described in Patent Document 1. It is presumed that good color development can be achieved even though the difference in the refractive index is not reduced. The upper limit of the particle size is not particularly limited, but from the viewpoint of productivity, it is preferably 650 nm or less, preferably 600 nm or less, further preferably 550 nm or less, and even more preferably 500 nm or less.

The above formula (2) defines that the thickness of the core layer is 40 to 210 nm. With this relatively thick core layer, an excellent balance between impact resistance and color development can be achieved. The thickness of the core layer is preferably 45 to 200 nm, more preferably 50 to 180 nm, further preferably 55 to 160 nm, further preferably 60 to 140 nm, and particularly preferably 65 to 130 nm.

(Shell layer)
The shell layer is a polymer layer formed on the surface of the core layer, and is a layer located on the outermost side of the graft copolymer particles. The shell layer improves the compatibility between the graft copolymer and the matrix resin, and enables the graft copolymer to be dispersed in the state of primary particles in the resin composition or a molded product made of the same. The polymer constituting the shell layer is preferably grafted on the polymer constituting the core layer. Further, a part of the polymer constituting the shell layer may be grafted on the polymer constituting the seed. The shell layer does not cover the entire surface of the core layer, but may cover at least a part of the surface of the core layer.

The shell layer is composed of a polymer of a monomer component containing at least one selected from the group consisting of (meth) acrylic acid ester, aromatic vinyl compound, and vinyl cyanide compound. These monomers can be appropriately selected from the specific examples of the monomers described above for the seed.

From the viewpoint of improving compatibility with the matrix resin containing acrylonitrile-styrene resin, the polymer constituting the shell layer is preferably composed of at least a polymer obtained by polymerizing an aromatic vinyl compound and a vinyl cyanide compound. In addition to these two types, (meth) acrylic acid ester may be further used. Styrene is preferable as the aromatic vinyl compound, and acrylonitrile is preferable as the vinyl cyanide compound.

From the viewpoint of compatibility with the matrix resin, the weight ratio of the aromatic vinyl compound to the entire polymer constituting the shell layer is preferably 30 to 95% by weight, more preferably 50 to 90% by weight, and 60 to 85% by weight. Is even more preferable. The weight ratio of the vinyl cyanide compound is preferably 5 to 70% by weight, more preferably 10 to 50% by weight, still more preferably 15 to 40% by weight.

The weight ratio of the shell layer in the graft copolymer can be appropriately determined in consideration of the weight ratio of the seed and core layer described above, but compatibility with the matrix resin is achieved while securing the ratio of the seed and core layer. From the viewpoint, for example, it may be 5 to 75% by weight, preferably 10 to 70% by weight, more preferably 20 to 65% by weight, further preferably 30 to 60% by weight, and particularly preferably 40 to 60% by weight.

The shell layer may be formed of a polymer having a crosslinked structure, but is preferably formed of a polymer having no crosslinked structure introduced therein. That is, the shell layer is preferably formed from a polymer synthesized without using a crosslinkable monomer such as a polyfunctional monomer. By not using a crosslinkable monomer in the shell layer, a free polymer can be produced, and the compatibility between the matrix resin and the graft copolymer can be improved.

(Method for producing graft copolymer)
The method for producing the graft copolymer of the present invention can be carried out by a conventional method, and specific examples will be described below. In producing the graft copolymer, first, a seed is formed. The seed can be produced by, for example, emulsion polymerization, suspension polymerization, microsuspension polymerization or the like, and for example, the method described in WO 2005/028546 can be used.

Next, the core layer is formed. The core layer can be formed by polymerizing the monomer component for the core layer by a known radical polymerization in the presence of a seed. When the seed is obtained as an emulsion, it is preferable that the monomer component for the core layer is polymerized by an emulsion polymerization method. When the core layer is composed of the first core layer and the second core layer, the monomer component for the first core layer may be polymerized, and then the monomer component for the second core layer may be polymerized.

Furthermore, a shell layer is formed. The shell layer can be formed by polymerizing the monomer component for the shell layer by a known radical polymerization in the presence of particles composed of a seed and a core layer. When the particles before the seed and core layers are formed and the shell layer is formed are obtained as an emulsion, the polymerization of the monomer components for the shell layer is preferably carried out by an emulsion polymerization method. For example, International Publication No. 2005 It can be produced according to the method described in 028546.

The emulsifier (dispersant) that can be used in emulsion polymerization is not particularly limited, and anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants and the like can be used. Further, a dispersant such as polyvinyl alcohol, alkyl-substituted cellulose, polyvinylpyrrolidone, and a polyacrylic acid derivative may be used. Among the above emulsifiers, the anionic surfactant is not particularly limited, and examples thereof include the following compounds: potassium laurate, potassium coconut fatty acid, potassium myristate, potassium oleate, potassium diethanolamine oleate, sodium oleate. , Sodium palmitate, potassium stearate, sodium stearate, mixed fatty acid soda soap, semi-hardened beef fat fatty acid soda soap, castor oil potassium soap and other fatty acid soaps; sodium dodecyl sulfate, higher alcohol sodium sulfate, triethanolamine dodecyl sulfate, dodecyl Alkyl sulfate esters such as ammonium sulfate, sodium polyoxyethylene alkyl ether sulfate, triethanolamine polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfate, and sodium 2-ethylhexyl sulfate; alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate. Sodium acid; sodium dialkyl sulfosuccinate such as sodium di-2-ethylhexyl sulfosuccinate; sodium alkylnaphthalene sulfonate; sodium alkyldiphenyl ether disulfonate; potassium alkyl phosphate; phosphate ester salt such as polyoxyethylene lauryl ether sodium phosphate Sodium salt of sodium phthalene sulfonic acid formalin condensate; polycarboxylic acid type polymer anion; sodium acyl (beef fat) methyl taurate; sodium acyl (palm) methyl taurate; sodium cocoyl acetylate; sodium α-sulfo fatty acid ester Sodium amide ether sulfonate; oleyl sarcosin; sodium lauroyl sarcosin; soap logate, etc.

The nonionic surfactant among the above emulsifiers is not particularly limited, and examples thereof include the following compounds: polyoxy such as polyoxyethylene nonylphenyl ether, polyoxyethylene oleyl ether, and polyoxyethylene lauryl ether. Polyoxyethylene sorbitan esters such as ethylene alkyl allyl ethers or polyoxyethylene alkyl ethers, polyoxyethylene sorbitan monolaurates, polyoxyethylene sorbitan monostearates, polyethylene glucol monolaurates, polyethylene glucol monostearates, Polyoxyethylene fatty acid esters such as polyethylene glucol monooleate, oxyethylene / oxypropylene block copolymers, etc.

The cationic surfactant among the above emulsifiers is not particularly limited, and examples thereof include the following compounds: alkylamine salts such as coconatamine acetate, stearylamine acetate, octadecylamine acetate, and tetradecylamine acetate; Tertiary ammonium salts such as lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, cetyltrimethylammonium chloride, distearyldimethylammonium chloride, alkylbenzyldimethylammonium chloride, hexadecyltrimethylammonium chloride, and behenyltrimethylammonium chloride.

The amphoteric surfactant among the above emulsifiers is not particularly limited, and examples thereof include the following compounds: alkyl betaines such as lauryl betaine, stearyl betaine, and dimethyl lauryl betaine; sodium lauryl diaminoethylglycine; amide betaine; imidazoline. Lauryl carboxymethyl hydroxyethyl imidazolinium betaine, etc.

These emulsifiers (dispersants) may be used alone or in combination of two or more. By adjusting the amount of the emulsifier used, the above-mentioned r1 and r2 can be controlled.

It is preferable to use a small amount of emulsifier (dispersant) as long as it does not interfere with the dispersion stability of the aqueous latex of the polymer particles. The higher the water solubility of the emulsifier (dispersant), the more preferable it is. When the water solubility is high, the emulsifier (dispersant) can be easily removed by washing with water, and adverse effects on the finally obtained resin composition or molded product can be easily prevented.

When the emulsion polymerization method is adopted, a known initiator, that is, 2,2'-azobisisobutyronitrile, hydrogen peroxide, potassium persulfate, ammonium persulfate and the like can be used as the pyrolytic initiator. ..

In addition, organic compounds such as t-butyl peroxyisopropyl carbonate, paramentan hydroperoxide, cumene hydroperoxide, dicumyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, and t-hexyl peroxide. Oxides; peroxides such as inorganic peroxides such as hydrogen peroxide, potassium persulfate, ammonium persulfate, and optionally sodium formaldehyde sulfoxylates, reducing agents such as glucose, and optionally iron sulfate (II). ), And if necessary, a chelating agent such as disodium ethylenediamine tetraacetate, and if necessary, a phosphorus-containing compound such as sodium pyrophosphate can be used in combination with a redox-type initiator.

When a redox-type initiator system is used, polymerization can be carried out even at a low temperature at which the peroxide does not substantially undergo thermal decomposition, and the polymerization temperature can be set in a wide range, which is preferable. Of these, it is preferable to use organic peroxides such as cumene hydroperoxide, dicumyl peroxide, and t-butyl hydroperoxide as the redox-type initiator. The amount of the initiator used, and when the redox-type initiator is used, the amount of the reducing agent, transition metal salt, chelating agent, etc. used can be used within a known range. Further, when polymerizing a monomer having two or more radically polymerizable double bonds, a known chain transfer agent can be used in a known range. Surfactants can be additionally used, but this is also in the known range.

Conditions such as polymerization temperature, pressure, and deoxygenation at the time of polymerization can be applied within a known range.

The radical copolymer used in the present invention preferably satisfies any one or more of the following properties (i)-(iii). Further, it is more preferable to satisfy any two or more, and it is further preferable to satisfy all three.

(I) The Izod impact strength measured according to the following measurement conditions is obtained for the test piece 1 having a length of 63.5 mm, a width of 12.7 mm, a thickness of 3.2 mm, and a v-notch manufactured according to the following test piece preparation conditions. , 30 kJ / m ² or more. It is preferably 35 kJ / m ² or more, more preferably 40 kJ / m ² or more, and further preferably 45 kJ / m ² or more.
[Test piece preparation conditions]:
(A) Aromatic polycarbonate resin with a viscosity average molecular weight of 19,000 (Panlite L-1225WX manufactured by Teijin Co., Ltd.) 74.4 parts by weight (b) Acrylonitrile-styrene resin (STYLAC T8701 manufactured by Asahi Kasei Co., Ltd.) 16 parts by weight (C) 9 parts by weight of the graft copolymer (d) 0.65 parts by weight of a polycarbonate resin masterbatch containing 30% by weight of carbon black (manufactured by Sowa Chemical Co., Ltd.) The mixture of the above (a) to (d) was added. A twin-screw extruder heated to a barrel temperature of 200 to 250 ° C. (TEX44SS manufactured by Nippon Steel Co., Ltd.) is kneaded under the condition of a screw rotation speed of 100 rpm to obtain extruded pellets. The pellets are dried at 80 ° C. for 5 hours in a hot air dryer, and a test piece is prepared in an injection molding machine (FAS100B manufactured by FANUC Co., Ltd.) under the conditions of a molding temperature of 250 ° C. and a mold temperature of 70 ° C.
[Measurement condition]:
The Izod impact strength at 10 ° C. is measured by a method conforming to the ASTM D256 standard.

(Ii) Regarding the test piece 2 having an ASTM D638 standard dumbbell type and a thickness of 3.2 mm, which was manufactured according to the test piece preparation conditions in (i) above, the L value measured according to the following measurement conditions is 20 or less. is there. It is preferably 15 or less, more preferably 13 or less, still more preferably 11 or less, and particularly preferably 10 or less.
[Measurement condition]:
According to JIS K8722 standard, the reflected L value is measured with a color difference meter (model: SE-2000) manufactured by Nippon Denshoku Kogyo Co., Ltd.

(Iii) The MFR value measured according to the following measurement conditions is 21 or more for the extruded pellets produced according to the procedure in the test piece preparation conditions in (i) above. It is preferably 23 or more, more preferably 24 or more, and even more preferably 25 or more.
[Measurement condition]:
According to the JIS K7210 A method, the extruded pellets are dried at 80 ° C. for 5 hours in a hot air dryer, and then the MFR value is measured under the conditions of a measurement temperature of 260 ° C. and a load of 5 kg.

The thermoplastic resin composition of the present invention contains flame retardants, lubricants, antibacterial agents, mold release agents, nucleating agents, plasticizers, heat stabilizers, antioxidants, light stabilizers, ultraviolet stabilizers, as required. Any additive such as a compatibilizer, a pigment, a dye and an inorganic substance additive can be blended. Those skilled in the art can appropriately set the blending amount of each additive.

The method for producing the thermoplastic resin composition of the present invention is not particularly limited, and a Henschel mixer, a tumbler mixer, or the like can be used for mixing the raw materials, and a single-screw or twin-screw extruder, a Banbury mixer, or the addition is used for melt kneading. A kneader such as a pressure kneader or a mixing roll can be used.

The thermoplastic resin composition of the present invention can be produced for various purposes and can be used for construction applications, electrical / electronic applications, vehicle applications, etc., for example, personal computers, liquid crystal displays, projectors, PDAs, printers, copiers, fax machines, etc. , Video cameras, digital cameras, mobile phones (smartphones), portable audio equipment, game machines, DVD recorders, microwave ovens, rice cookers, and other electrical and electronic applications; road light-transmitting plates, light-collecting windows, carports, lighting lenses, etc. It can be used for construction applications such as lighting covers, sizing for building materials, doors, etc .; for automobiles such as handles, shift levers, and vibration isolators, and for vehicles such as train windows, displays, lighting, and driver's seat panels. In particular, taking advantage of its excellent impact resistance and color development, interior and exterior materials for automobiles, exterior materials for electrical appliances such as mobile phones and smartphones, interior and exterior for civil engineering and construction such as floors, windows, interior and exterior walls, daylighting parts, and road signs. It can be suitably used for materials and the like.

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples.

(Refractive index of seed)
The refractive index of the seed was calculated based on the refractive index of each monomer used at the time of forming the seed and the ratio of its use. Specifically, it is as follows. The refractive index of methyl methacrylate (hereinafter referred to as MMA) is 1.494, the refractive index of butyl acrylate (hereinafter referred to as BA) is 1.463, the refractive index of styrene (hereinafter referred to as ST) is 1.595, and acrylonitrile (hereinafter referred to as AN). ) With a refractive index of 1.516, and calculated based on the following equation 1. The weight ratio of each monomer shall be the weight ratio of each monomer to the total amount of seeds.
(Equation 1)
Refractive index of seed = (MMA refractive index XMMA weight ratio / 100) + (BA refractive index XBA weight ratio / 100) + (ST refractive index XST weight ratio / 100) + (AN refractive index XAN Weight ratio / 100)

(Refractive index of matrix resin)
The refractive index of each resin was measured using a 2 mm plate of AS resin or polycarbonate resin (hereinafter referred to as PC resin) and an Abbe refractometer 2T manufactured by Atago Co., Ltd. in accordance with JIS K7142 standard. When the matrix resin was a mixture, it was calculated based on the following formula 2.
(Equation 2)
Refractive index of matrix resin = (refractive index of AS resin X weight ratio of AS resin to total matrix resin / 100) + (refractive index of PC resin X weight ratio of PC resin to total matrix resin / 100)

(Volume average particle size)
The volume average particle size was measured in the latex state of the seed or in the latex state of the particles before the seed and the core layer were formed and the shell layer was formed. As a measuring device, MICROTRAC UPA150 manufactured by Nikkiso Co., Ltd. was used.

(Polymerization conversion rate)
A part of the obtained latex was collected and precisely weighed, dried in a hot air dryer at 120 ° C. for 1 hour, and the weight after drying was precisely weighed as the solid content. Next, the ratio of the precision results before and after drying was determined as the ratio of solid components in latex. Finally, using this solid component ratio, the polymerization conversion rate was calculated by the following formula 3.
(Equation 3)
Polymerization conversion rate = (total weight of charged raw materials x solid component ratio-total weight of raw materials other than monomer) / weight of charged monomer x 100 (%)

(Izod impact strength)
The mixture of each example and comparative example is kneaded with a twin-screw extruder (TEX44SS manufactured by Japan Steel Works, Ltd.) heated to a barrel temperature of 200 to 250 ° C. under the condition of a screw rotation speed of 100 rpm to obtain extruded pellets. It was. The pellets were dried at 80 ° C. for 5 hours in a hot air dryer, and the length was 63.5 mm under the conditions of an injection molding machine (FAS100B manufactured by FANUC Corporation) at a molding temperature of 250 ° C. and a mold temperature of 70 ° C. A test piece 1 having a width of 12.7 mm, a thickness of 3.2 mm, and a v-notch was prepared. The Izod impact strength of the obtained test piece 1 was measured at −30 ° C., 0 ° C., 10 ° C., and 23 ° C. by a method conforming to the ASTM D256 standard.

(L value)
Under the same conditions as the Izod impact strength test piece 1, a dumbbell type test piece 2 having an ASTM D638 standard and a thickness of 3.2 mm was produced. The reflected L value of the obtained test piece 2 was measured with a color difference meter (model: SE-2000) manufactured by Nippon Denshoku Kogyo Co., Ltd. in accordance with JIS K8722 standard. The lower the L value, the darker the black color, which means that the color development property is good.

(MFR)
Extruded pellets prepared under the above-mentioned conditions regarding Izod impact strength are dried in a hot air dryer at 80 ° C. for 5 hours according to the JIS K7210 A method, and then the MFR value is determined under the conditions of a measurement temperature of 260 ° C. and a load of 5 kg. It was measured.

(Examples 1 to 20 and Comparative Examples 1 to 7)
A graft copolymer composed of a seed, a core layer, and a shell layer was prepared based on the weight ratios shown in each table. In the process of preparation, the volume average particle diameter (2 × r1) of the seed and the volume average particle diameter (2 × r2) of the particles before the seed and the core layer are formed and the shell layer is formed are measured. The obtained 2 × r2 numerical value and the calculated r2-r1 numerical value are shown in each table.

The specific procedure for producing and acquiring the graft copolymer in Example 6 as a typical graft copolymer is shown below. The procedure for producing the graft copolymer of Comparative Example 1 will also be described later. The procedure for producing and obtaining the graft copolymer in Examples other than Example 6 or Comparative Examples other than Comparative Example 1 conforms to the following description regarding Example 6, but the amount of the emulsifier used is the particle size of the seed. It was changed as appropriate according to the thickness of the core layer and the amount of monomer used. The weight ratios of the seed, core layer (first core layer and second core layer), and shell layer in the graft copolymer are as shown in each table, but the monomer species used in each layer are Examples. It is the same as No. 6, and the usage ratio of the monomer in each layer is the same as the usage ratio of the monomer in Example 6. However, with respect to Example 19 and Comparative Examples 6 and 7, the monomer species used in the seed and the usage ratio thereof were changed.

(Production of Graft Copolymer of Example 6)
180 parts by weight of deionized water and 0.5% by weight of sodium dioctyl sulfosuccinate aqueous solution in a glass reactor having a thermometer, a stirrer, a reflux condenser, a nitrogen inlet, and a device for adding a monomer and an emulsifier. .023 parts by weight was charged and the temperature was raised to 60 ° C. while stirring in a nitrogen stream.

There, 4.75 parts by weight of methyl methacrylate (hereinafter referred to as MMA), 0.25 parts by weight of butyl acrylate (hereinafter referred to as BA), 0.25 parts by weight of allyl methacrylate, and 0.015 parts by weight of cumene hydroperoxide. Was added. Next, 0.0033 parts by weight and 5 parts by weight of a mixed solution prepared by dissolving disodium ethylenediaminetetraacetate and ferrous sulfate in deionized water at a mixing ratio of 4: 1 to a concentration of 0.5% by mass. 0.04 parts by weight of sodium formaldehyde sulfoxylate at a% concentration was charged. In that state, the mixture was stirred for 60 minutes to form seed particles with a polymerization conversion rate of 97%.

0.005 part by weight of cumene hydroperoxide was charged therein, and a mixture of 42.5 part by weight of BA and 0.2 part by weight of allyl methacrylate was added over 120 minutes. During the addition, 0.005 parts by weight of cumene hydroperoxide was added according to the progress of polymerization. After the addition, the mixture was stirred for 60 minutes while raising the temperature to 65 ° C. to form a first core layer with a polymerization conversion rate of 98%.

A mixture of disodium ethylenediamine tetraacetate and ferrous sulfate at a mixing ratio of 4: 1 and dissolved in deionized water so as to have a concentration of 0.5% by weight was charged therein in an amount of 0.0027 parts by weight. A mixture of 2.5 parts by weight, 0.06 parts by weight of allyl methacrylate, and 0.0063 parts by weight of cumene hydroperoxide was added over 10 minutes. After the addition, the mixture was stirred for 60 minutes to form a second core layer with a polymerization conversion rate of 99%.

0.16 parts by weight of sodium formaldehyde sulfoxylate having a concentration of 5% by weight was charged therein, and 12.7 parts by weight of acrylonitrile (hereinafter referred to as AN), 36.3 parts by weight of styrene (hereinafter referred to as ST), BA1.0. A mixture of 0.12 parts by weight of t-dodecyl mercaptan and 0.2 parts by weight of t-butyl hydroperoxide was added over 180 minutes. After the addition, 0.0051 parts by mass, 5% by weight of a mixed solution in which disodium ethylenediaminetetraacetate and ferrous sulfate were dissolved in deionized water at a mixing ratio of 4: 1 to a concentration of 0.5% by mass. 0.05 part by weight of sodium formaldehyde sulfoxylate was charged and stirred for 10 minutes. Then, 0.05 part by weight of t-butyl hydroperoxide was charged and stirred for 20 minutes. Then, 0.05 part by weight of t-butyl hydroperoxide was charged and stirred for 40 minutes to form a shell layer having a polymerization conversion rate of 99.5%. From the above, a latex of a graft copolymer composed of a seed, a core layer (first core layer and second core layer), and a shell layer was obtained.

(Production of Graft Copolymer of Comparative Example 1)
155 parts by weight of deionized water, 0.48 parts by weight of boric acid, 0.05 parts by mass of sodium carbonate in a glass reactor equipped with a thermometer, agitator, a reflux condenser, a nitrogen inlet, and a device for adding monomers and emulsifiers. , And 0.016 parts by weight of an aqueous solution of polyoxyethylene lauryl ether phosphoric acid having a concentration of 1.0% by mass was charged, and the temperature was raised to 50 ° C. while stirring in a nitrogen stream.

A mixture of 8.5 parts by weight of BA and 0.04 parts by weight of allyl methacrylate was added thereto, and 0.0017 parts by weight of t-butyl hydroperoxide was charged. Next, 0.007 parts by weight and 5% by weight of a mixed solution in which disodium ethylenediaminetetraacetate and ferrous sulfate were dissolved in deionized water at a mixing ratio of 4: 1 to a concentration of 0.5% by mass. 0.2 part by weight of sodium formaldehyde sulfoxylate having a concentration was charged and stirred for 50 minutes. A mixture of 76.5 parts by weight of BA, 0.38 parts by weight of allyl methacrylate, 0.025 parts by weight of t-butyl hydroperoxide, and 0.765 parts by weight of polyoxyethylene lauryl ether phosphoric acid was added thereto over 220 minutes. did. During the addition, 0.02 part by weight of a 2% by weight aqueous sodium hydroxide solution was appropriately added. After adding the mixture, 0.015 parts by weight of t-butyl hydroperoxide was added and stirred for 45 minutes to form a core layer with a polymerization conversion rate of 98.5%.

A mixture of 13.5 parts by weight of MMA, 1.5 parts by weight of BA, 0.007 parts by weight of t-butyl hydroperoxide, and 0.14 parts by weight of polyoxyethylene lauryl ether phosphoric acid was added thereto over 50 minutes. During the addition, 0.01 part by weight of a 2% by weight aqueous sodium hydroxide solution was appropriately added. After adding the mixture, the mixture was stirred for 15 minutes, and 0.015 parts by weight of t-butyl hydroperoxide was added. Then, the mixture was stirred for 15 minutes, 0.03 part by weight of t-butyl hydroperoxide was added, and the mixture was further stirred for 30 minutes to form a shell layer having a polymerization conversion rate of 100%. From the above, a latex of a graft copolymer composed of only a core layer and a shell layer was obtained.

(Acquisition of white resin powder of graft copolymer)
500 parts by weight of deionized water and 5 parts by weight of a 25% by mass calcium chloride aqueous solution were heated to 70 ° C., and the latex of the graft copolymer was added thereto to obtain a slurry containing coagulated latex particles. Then, the solidified latex particle slurry was heated to 95 ° C., dehydrated and dried to obtain a graft copolymer as a white resin powder.

(Manufacturing of thermoplastic resin composition)
The white resin powder of the obtained graft copolymer, an aromatic polycarbonate resin having a viscosity average molecular weight of 19,000 (Panlite L-1225WX manufactured by Teijin Co., Ltd.), and an acrylonitrile-styrene resin (STYLAC T8701 manufactured by Asahi Kasei Co., Ltd.). , And a polycarbonate resin masterbatch containing 30% by weight of carbon black (manufactured by Sowa Kagaku Co., Ltd.) was mixed in the number of parts listed in each table, and the mixture was obtained according to the above-mentioned conditions. The MFR and L values were measured and the results are shown in each table.

The thermoplastic resin composition obtained in each Example in Table 1, Izod impact strength measured at 10 ° C. is 30 kJ / ^{m 2} or more, at -30 Izod impact strength measured at ° C. is 14 kJ / ^{m 2} or more, and Since the L value was 20 or less, it can be seen that both impact resistance and color development are excellent. On the other hand, it can be seen that the thermoplastic resin composition obtained in Comparative Example 1 using the graft copolymer having no seed has an L value of 21 and is inferior in color development. Further, the thermoplastic resin compositions obtained in Comparative Examples 2 to 4 using a graft copolymer having a core layer thickness of r2-r1 of less than 40 nm had an Izod impact strength of 30 kJ / m measured at 10 ° C. ^If it is less than ² , it can be seen that the impact resistance is inferior. Further, the thermoplastic resin composition obtained in Comparative Example 5 using a graft copolymer having a diameter of 2xr2 of less than 300 nm, which is the diameter of the particles composed of the seed and the core layer, had an Izod impact strength measured at −30 ° C. It can be seen that the impact resistance at low temperature is inferior.

In Examples 13 to 16 in Table 2, the number of copies of the graft copolymer was changed, but all of them showed good impact resistance and color development. Further, in Examples 17 and 18, although the resin composition in the matrix resin was changed, both showed good impact resistance and color development.

In Example 19 of Table 3, the difference between the refractive index of the seed and the refractive index of the matrix resin was 0.07, which showed good impact resistance and color development, whereas Comparative Example 6 had the refractive index. It can be seen that the difference between the two is 0.06, the Izod impact strength measured at −30 ° C. is low, and the impact resistance at low temperature is inferior.

In Example 20 and Comparative Example 7 in Table 4, the resin composition of the matrix resin was changed. In Example 20, the difference between the refractive index of the seed and the refractive index of the matrix resin was 0.073, and in Comparative Example 7, the difference in the refractive index was 0.03, but in Example 20, comparison was made. The impact resistance was better than that of Example 7.

Claims

A thermoplastic resin composition containing a seed, a particulate graft copolymer composed of a core layer formed on the surface of the seed, and a shell layer formed on the surface of the core layer, and a matrix resin. hand,
The matrix resin contains an acrylonitrile-styrene resin and contains.
The seed comprises a polymer of monomer components containing at least one selected from the group consisting of (meth) acrylic acid ester, aromatic vinyl compound, and vinyl cyanide compound.
The difference between the refractive index of the seed and the refractive index of the matrix resin is 0.07 or more.
The core layer is a polymer of a monomer component containing at least one kind of acrylic acid ester and is composed of a polymer having a crosslinked structure.
The shell layer is composed of a polymer of a monomer component containing at least one selected from the group consisting of (meth) acrylic acid ester, aromatic vinyl compound, and vinyl cyanide compound.
The graft copolymer is a thermoplastic resin composition that satisfies the following formulas (1) and (2).
300 ≦ 2xr2 ≦ 700 (1)
40 ≦ r2-r1 ≦ 210 (2)
(In the formula, r1 represents the radius (nm) of the seed, and r2 represents the radius (nm) of the particles composed of the seed and the core layer.)
The thermoplastic resin composition according to claim 1, wherein the core layer occupies 83% by weight or less in the graft copolymer.
The thermoplastic resin composition according to claim 1 or 2, wherein the seed comprises a polymer obtained by polymerizing 80 to 100% by weight of a (meth) acrylic acid ester and 0 to 20% by weight of an aromatic vinyl compound.
The thermoplastic resin composition according to claim 3, wherein the (meth) acrylic acid ester in the seed contains an alkyl methacrylate ester.
The thermoplastic resin composition according to any one of claims 1 to 4, wherein the polymer constituting the seed has a crosslinked structure.
The thermoplastic resin composition according to any one of claims 1 to 5, wherein the core layer is composed of two or more different layers.
The thermoplastic resin composition according to any one of claims 1 to 6, wherein the shell layer comprises a polymer obtained by polymerizing at least an aromatic vinyl compound and a vinyl cyanide compound.
The thermoplastic resin composition according to any one of claims 1 to 7, wherein the weight ratio of the graft copolymer to the total of the matrix resin and the graft copolymer is 1 to 60% by weight.
The thermoplastic resin composition according to any one of claims 1 to 8, wherein the matrix resin further contains a polycarbonate resin.
The thermoplastic resin composition according to claim 9, wherein the weight ratio of the acrylonitrile-styrene resin to the polycarbonate resin is 25:75 to 5:95.
The thermoplastic resin composition according to claim 9 or 10, wherein the weight ratio of the graft copolymer to the total of the matrix resin and the graft copolymer is 2 to 20% by weight.
The Izod impact strength measured according to the following measurement conditions for the test piece 1 having a length of 63.5 mm, a width of 12.7 mm, a thickness of 3.2 mm, and a v-notch manufactured according to the following test piece preparation conditions is 30 kJ / The thermoplastic resin composition according to any one of claims 1 to 11, which is m 2 or more.
[Test piece preparation conditions]:
(A) Aromatic polycarbonate resin with a viscosity average molecular weight of 19,000 (Panlite L-1225WX manufactured by Teijin Co., Ltd.) 74.4 parts by weight (b) Acrylonitrile-styrene resin (STYLAC T8701 manufactured by Asahi Kasei Co., Ltd.) 16 parts by weight (C) 9 parts by weight of the graft copolymer (d) 0.65 parts by weight of a polycarbonate resin masterbatch containing 30% by weight of carbon black (manufactured by Sowa Chemical Co., Ltd.) The mixture of the above (a) to (d) was added. A twin-screw extruder heated to a barrel temperature of 200 to 250 ° C. (TEX44SS manufactured by Nippon Steel Co., Ltd.) is kneaded under the condition of a screw rotation speed of 100 rpm to obtain extruded pellets. The pellets are dried at 80 ° C. for 5 hours in a hot air dryer, and a test piece is prepared in an injection molding machine (FAS100B manufactured by FANUC Co., Ltd.) under the conditions of a molding temperature of 250 ° C. and a mold temperature of 70 ° C.
[Measurement condition]:
The Izod impact strength at 10 ° C. is measured by a method conforming to the ASTM D256 standard.
Claimed that the L value measured according to the following measurement conditions is 20 or less for the test piece 2 of the ASTM D638 standard dumbbell type and thickness 3.2 mm manufactured according to the test piece preparation condition according to claim 12. Item 2. The thermoplastic resin composition according to any one of Items 1 to 12.
[Measurement condition]:
According to JIS K8722 standard, the reflected L value is measured with a color difference meter (model: SE-2000) manufactured by Nippon Denshoku Kogyo Co., Ltd.
The thermoplastic according to any one of claims 1 to 13, wherein the extruded pellet produced according to the procedure in the test piece preparation condition according to claim 12 has an MFR value of 21 or more measured according to the following measurement conditions. Resin composition.
[Measurement condition]:
According to the JIS K7210 A method, the extruded pellets are dried at 80 ° C. for 5 hours in a hot air dryer, and then the MFR value is measured under the conditions of a measurement temperature of 260 ° C. and a load of 5 kg.
A molded product obtained by molding the thermoplastic resin composition according to any one of claims 1 to 14.