阅读说明：本技术 热塑性树脂组合物及成型体 (Thermoplastic resin composition and molded article ) 是由 园山亚里纱 真部友也 芳村大辉 于 2020-03-10 设计创作，主要内容包括：本发明提供由种子、芯层、及壳层构成的粒子状的接枝共聚物、及含有基体树脂的热塑性树脂组合物。上述基体树脂含有丙烯腈-苯乙烯树脂。上述种子的折射率与上述基体树脂的折射率之差为0.07以上。上述芯层由具有交联结构且含有丙烯酸酯的单体成分的聚合物形成。上述接枝共聚物满足下述式。式中,r1表示上述种子的半径(nm),r2表示由上述种子和上述芯层构成的粒子的半径(nm)。300≤2×r2≤700;40≤r2-r1≤210。(The present invention provides a particulate graft copolymer composed of a seed, a core layer, and a shell layer, and a thermoplastic resin composition containing a matrix resin. The matrix resin contains an acrylonitrile-styrene resin. 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 formed of a polymer of a monomer component having a crosslinked structure and containing an acrylate. The above graft copolymer satisfies the following formula. Wherein r1 represents the radius (nm) of the seed, and r2 represents the radius (nm) of the particle composed of the seed and the core layer. 300 is more than or equal to 2 xr 2 is more than or equal to 700, and 40 is more than or equal to r2-r1 is more than or equal to 210.)

1. A thermoplastic resin composition comprising a particulate graft copolymer and a matrix resin, wherein the particulate graft copolymer comprises a seed, a core layer formed on the surface of the seed, and a shell layer formed on the surface of the core layer,

the matrix resin comprises an acrylonitrile-styrene resin,

the seed is formed of a polymer containing a monomer component selected from at least one of a (meth) acrylate, an aromatic vinyl compound, and a 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 formed of a polymer of a monomer component having a crosslinked structure and containing at least one acrylate,

the shell layer is formed of a polymer containing at least one monomer component selected from the group consisting of (meth) acrylic acid esters, aromatic vinyl compounds, and vinyl cyanide compounds,

the graft copolymer satisfies the following formulae (1) and (2),

300≤2×r2≤700 (1)

40≤r2-r1≤210 (2)

wherein r1 represents the radius (nm) of the seed, and r2 represents the radius (nm) of the particle composed of the seed and the core layer.

2. The thermoplastic resin composition according to claim 1, wherein,

the core layer accounts for 83 wt% or less of the graft copolymer.

3. The thermoplastic resin composition according to claim 1 or 2, wherein,

the seed is composed of a polymer obtained by polymerizing 80 to 100 wt% of (meth) acrylate and 0 to 20 wt% of an aromatic vinyl compound.

4. The thermoplastic resin composition according to claim 3, wherein,

the (meth) acrylate in the seed comprises an alkyl methacrylate.

5. The thermoplastic resin composition according to any one of claims 1 to 4, wherein,

the polymer constituting the seed has a crosslinked structure.

6. The thermoplastic resin composition according to any one of claims 1 to 5, wherein,

the core layer is composed of two or more layers different from each other.

7. The thermoplastic resin composition according to any one of claims 1 to 6, wherein,

the shell layer is formed by a polymer formed by polymerizing at least an aromatic vinyl compound and a vinyl cyanide compound.

8. The thermoplastic resin composition according to any one of claims 1 to 7, wherein,

the graft copolymer accounts for 1-60 wt% relative to the total weight of the matrix resin and the graft copolymer.

9. The thermoplastic resin composition according to any one of claims 1 to 8, wherein,

the matrix resin further contains a polycarbonate resin.

10. The thermoplastic resin composition of claim 9, wherein,

the weight ratio of the acrylonitrile-styrene resin to the polycarbonate resin is 25: 75-5: 95.

11. The thermoplastic resin composition of claim 9 or 10, wherein,

the graft copolymer accounts for 2-20 wt% relative to the total weight of the matrix resin and the graft copolymer.

12. The thermoplastic resin composition according to any one of claims 1 to 11, wherein,

the Izod impact strength of 30kJ/m was measured under the following measurement conditions on a test piece 1 having a length of 63.5mm, a width of 12.7mm, a thickness of 3.2mm and a notch formed under the following test piece production conditions²In the above-mentioned manner,

test piece production conditions:

(a) 74.4 parts by weight of an aromatic polycarbonate resin having a viscosity-average molecular weight of 19000 (Panlite L-1225WX, manufactured by Diniu corporation)

(b) Acrylonitrile-styrene resin (STYLACT 8701, Asahi Kasei K.K.) 16 parts by weight

(c) 9 parts by weight of the graft copolymer

(d) 0.65 part by weight of a polycarbonate resin master batch (manufactured by Takara chemical Co., Ltd.) containing 30% by weight of carbon black

Kneading the mixture of (a) to (d) with a twin-screw extruder (TEX 44SS, made by Nippon Steel Co., Ltd.) heated to a barrel temperature of 200 to 250 ℃ at a screw rotation speed of 100rpm to obtain extruded pellets, drying the pellets with a hot air dryer at 80 ℃ for 5 hours, and producing test pieces with an injection molding machine (FAS 100B, made by FANUC corporation) at a molding temperature of 250 ℃ and a mold temperature of 70 ℃;

the measurement conditions were as follows:

the Izod impact strength at 10 ℃ was measured by a method based on ASTM D256 standard.

13. The thermoplastic resin composition according to any one of claims 1 to 12, wherein,

an L value measured under the following measurement conditions on a test piece 2 of 3.2mm thick in a dumbbell type according to ASTM D638 produced under the test piece production conditions of claim 12 is 20 or less,

the measurement conditions were as follows:

the reflection L value was measured by a color difference meter (model: SE-2000) manufactured by Nippon Denshoku industries Co., Ltd., according to JIS K8722.

14. The thermoplastic resin composition according to any one of claims 1 to 13, wherein,

the MFR value of the extruded pellets produced in the order of the test piece production conditions according to claim 12 measured under the following measurement conditions is 21 or more,

the measurement conditions were as follows:

the extruded pellets were dried at 80 ℃ for 5 hours by a hot air dryer according to JIS K7210A, and then the MFR value was measured under conditions of a measurement temperature of 260 ℃ and a load of 5 kg.

15. A molded article obtained by molding the thermoplastic resin composition according to any one of claims 1 to 14.

Technical Field

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

Background

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

However, when a molded article is produced from such a thermoplastic resin composition containing a rubber-containing graft copolymer, the color tone of the molded article may be changed by the graft copolymer, resulting in a decrease in color developability.

In order to improve impact resistance and obtain a thermoplastic resin composition having good color development, a method of reducing the difference in refractive index between the matrix resin and the graft copolymer is generally used. As a graft copolymer suitable for this case, methyl methacrylate-butadiene-styrene resin (MBS) is widely used. However, since MBS contains butadiene rubber, deterioration of impact resistance and color development due to deterioration of ultraviolet rays is likely to be a problem, and the use of MBS tends to be limited to indoor use.

Not only butadiene rubbers having such a limitation, but also graft copolymers containing acrylic rubbers are known.

Patent document 1 discloses a resin composition containing an ASA (acrylonitrile-acrylate-styrene) graft copolymer as an acrylic rubber-containing graft copolymer and a matrix resin. It is described that the difference between the refractive index of the seed and shell layer of the graft copolymer comprising the seed, core layer and shell layer and the refractive index of the matrix resin is reduced, and the monomer composition of the seed and shell layer is selected so as to satisfy 0.035, and the color developability is improved by reducing the thickness of the core (r2-r1) having a large difference in refractive index from the matrix resin.

On the other hand, as a thermoplastic resin used for a molded article used for automobile interior and exterior applications, etc., it is known that a styrene-acrylonitrile copolymer and an alloy of the copolymer and a polycarbonate resin can be used.

Documents of the prior art

Patent document

Patent document 1: japanese Kohyo publication 2014-527570

Disclosure of Invention

Problems to be solved by the invention

According to the method described in patent document 1, the difference in refractive index between the seed and the matrix resin must be reduced, and therefore the monomer composition of the seed is limited. However, the seed composition described in patent document 1 has a disadvantage that the polymerization rate is slow and the productivity is lowered when a seed having a large particle size is to be produced. Further, since the thickness of the core layer having a function of ensuring impact resistance needs to be reduced, impact resistance tends to be lowered.

In view of the above-mentioned state of the art, an object of the present invention is to provide a thermoplastic resin composition containing a graft copolymer and a matrix resin, which exhibits excellent impact resistance and color development without reducing the difference in refractive index between the seed of the graft copolymer and the matrix resin.

Means for solving the problems

The present inventors have studied a graft copolymer which can exhibit excellent impact resistance and color development by being blended with a styrene-acrylonitrile copolymer-containing matrix resin widely used for automobile interior and exterior applications and the like. As a result, they found that: by setting the diameter of the particles composed of the seed and the core layer and the thickness of the core layer in the graft copolymer composed of the seed, the core layer and the shell layer to specific ranges, excellent impact resistance and color development can be exhibited without using a monomer composition of the seed that reduces the difference in refractive index between the seed and the matrix resin.

That is, the present invention relates to a thermoplastic resin composition comprising a particulate graft copolymer and a matrix resin, wherein the particulate graft copolymer comprises a seed, a core layer formed on the surface of the seed, and a shell layer formed on the surface of the core layer,

the above-mentioned matrix resin contains an acrylonitrile-styrene resin,

the seed is formed of a polymer containing a monomer component selected from at least one of (meth) acrylate, an aromatic vinyl compound, and a 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 formed of a polymer containing a monomer component having a crosslinked structure and containing at least one acrylate, the shell layer is formed of a polymer containing a monomer component selected from at least one of (meth) acrylate, an aromatic vinyl compound, and a vinyl cyanide compound, and the graft copolymer satisfies the following formulae (1) and (2),

300≤2×r2≤700 (1)

40≤r2-r1≤210 (2)

(wherein r1 represents the radius (nm) of the seed, and r2 represents the radius (nm) of the particle comprising the seed and the core layer.)

The weight ratio of the core layer in the graft copolymer is preferably 83 wt% or less. Preferably, the seed is composed of a polymer obtained by polymerizing 80 to 100 wt% of (meth) acrylate and 0 to 20 wt% of an aromatic vinyl compound. Preferably, the (meth) acrylate in the seed contains an alkyl methacrylate. The seed-constituting polymer preferably has a crosslinked structure. The core layer is preferably composed of two or more different layers. Preferably, the shell layer is formed of a polymer obtained by polymerizing at least an aromatic vinyl compound and a vinyl cyanide compound. The graft copolymer is preferably present in a weight ratio of 3 to 50 wt% based on the total of the base resin and the graft copolymer.

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. The graft copolymer is preferably present in a weight ratio of 3 to 15 wt% based on the total of the base resin and the graft copolymer.

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

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a thermoplastic resin composition containing a graft copolymer and a matrix resin, which exhibits excellent impact resistance and color development without reducing the difference in refractive index between the seed of the graft copolymer and the matrix resin. Further, the thermoplastic resin composition according to a preferred embodiment of the present invention has excellent fluidity when melted, and therefore can be easily used for thin-wall molding and large-sized molded products.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail.

(thermoplastic resin composition)

The thermoplastic resin composition of the present invention contains a matrix resin and a graft copolymer as an impact resistance improver. The ratio of the base resin to the graft copolymer is not particularly limited, and may be appropriately set according to the composition of the base resin. The proportion by weight of the graft copolymer relative to the total amount of the base resin and the graft copolymer may be usually in the range of 1 to 60% by weight from the viewpoint of ensuring good color development while exhibiting excellent impact resistance. More specifically, when the matrix resin is formed of only an acrylonitrile-styrene resin, the weight ratio is preferably 5 to 55 wt%, more preferably 10 to 50 wt%, and still more preferably 15 to 45 wt%. When the matrix resin is a mixture of an acrylonitrile-styrene resin and a polycarbonate resin, the weight ratio is preferably 2 to 20 wt%, more preferably 3 to 19 wt%, still more preferably 4 to 18 wt%, and particularly preferably 5 to 17 wt%.

(matrix resin)

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

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

The thermoplastic resin other than the acrylonitrile-styrene resin is not particularly limited, and examples thereof include: polycarbonate resins, polyamide resins, acrylic resins, styrene resins, polyphenylene ether resins, and the like. These resins may be used alone or in combination of two or more.

Among them, polycarbonate resins are preferred. The polycarbonate resin is preferably obtained by reacting a phenolic compound having a valence of 2 or more with a carbonic acid diester compound such as phosgene or diphenyl carbonate.

The above-mentioned phenolic compound having a valence of 2 or more is not particularly limited, and examples thereof include: 2, 2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A), bis (4-hydroxyphenyl) methane, 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-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-bis (3, 5-dimethyl-4-hydroxyphenyl) propane, 1-ethyl-1, 1-bis (4-hydroxyphenyl) propane, 2-bis (3, 5-dichloro-4-hydroxyphenyl) propane, 2-bis (3, 5-dibromo-4-hydroxyphenyl) propane, 2-bis (3-chloro-4-hydroxyphenyl) propane, 2-bis (3-methyl-4-hydroxyphenyl) propane, 2-bis (3-fluoro-4-hydroxyphenyl) propane, 1-bis (4-hydroxyphenyl) butane, 2-bis (4-hydroxyphenyl) propane, 2-bis (3-fluoro-4-hydroxyphenyl) propane, 1-bis (4-hydroxyphenyl) propane, 2-bis (3-hydroxy-phenyl) propane, 2-bis (4-hydroxy-phenyl) propane, 2-bis (4-hydroxy-phenyl) propane, 2, or 2, or 2, or, 1, 4-bis (4-hydroxyphenyl) butane, 2-bis (4-hydroxyphenyl) pentane, 4-methyl-2, 2-bis (4-hydroxyphenyl) pentane, 2-bis (4-hydroxyphenyl) hexane, 4-bis (4-hydroxyphenyl) heptane, 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, dihydroxydiarylcycloalkanes such as 5-dichloro-4-hydroxyphenyl) cyclohexane and 1, 1-bis (4-hydroxyphenyl) cyclodecane, dihydroxydiarylsulfones such as bis (4-hydroxyphenyl) sulfone, bis (3, 5-dimethyl-4-hydroxyphenyl) sulfone and bis (3-chloro-4-hydroxyphenyl) sulfone, dihydroxyaryl ethers such as bis (4-hydroxyphenyl) ether and bis (3, 5-dimethyl-4-hydroxyphenyl) ether, dihydroxyaryl ketones such as 4,4 '-dihydroxybenzophenone and 3, 3', 5,5 '-tetramethyl-4, 4' -dihydroxybenzophenone, dihydroxydiaryl sulfides such as bis (4-hydroxyphenyl) sulfide, bis (3-methyl-4-hydroxyphenyl) sulfide, Dihydroxydiaryl sulfides such as bis (3, 5-dimethyl-4-hydroxyphenyl) sulfide, dihydroxydiaryl sulfoxides such as bis (4-hydroxyphenyl) sulfoxide, dihydroxydiphenyl compounds such as 4, 4' -dihydroxydiphenyl, and dihydroxyaryl fluorenes such as 9, 9-bis (4-hydroxyphenyl) fluorene. In addition to the above-mentioned phenol compounds having a valence of 2, dihydroxybenzenes such as quinol, resorcinol and methyl quinol, dihydroxynaphthalenes such as1, 5-dihydroxynaphthalene and 2, 6-dihydroxynaphthalene, and the like can be used as the phenol compounds having a valence of 2.

The phenolic compound having a valence of 3 or more may be used in a range where the obtained polycarbonate resin retains thermoplasticity. Examples of the above-mentioned phenolic compound having a valence of 3 or more include 2,4,4 '-trihydroxybenzophenone, 2', 4,4 '-tetrahydroxybenzophenone, 2,4, 4' -trihydroxyphenyl ether, 2 ', 4, 4' -tetrahydroxyphenyl ether, 2,4,4 '-trihydroxydiphenyl-2-propane, 2' -bis (2, 4-dihydroxy) propane, 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" -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-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 ] methane, bis [ 2-hydroxy-3- (2 ' -hydroxy-5 ' -isopropylbenzyl) -5-methylphenyl ] methane, tetrakis (4-hydroxyphenyl) methane, tris (4-hydroxyphenyl) phenylmethane, 2 ', 4 ', 7-trihydroxyflavan, 2,4, 4-trimethyl-2', 4 ', 7-trihydroxyflavan, 1, 3-bis (2', 4 '-dihydroxyphenylisopropyl) benzene, tris (4' -hydroxyphenyl) -pentyl-s-triazine, and the like.

These phenolic compounds having a valence of 2 or more may be used alone or in combination of two or more.

The polycarbonate resin may contain a component for forming a branched polycarbonate resin as needed, in addition to the phenolic compound having a valence of 3 or more, within a range not to impair thermoplasticity. Examples of the component (branching agent) other than the phenolic compound having a valence of 3 or more for obtaining the branched polycarbonate-based resin include: phloroglucinol, mellitic acid, trimellitic acid chloride, trimellitic anhydride, gallic acid, n-propyl gallate, protocatechuic acid, pyromellitic dianhydride, 3, 5-dihydroxybenzoic acid, 2, 4-dihydroxybenzoic acid, resorcinol aldehyde, trimethyl chloride (trimethychloride), isatinbis (o-cresol), trimethyl trichloride (trimethyltrichloride), 4-chloroformyl phthalic anhydride, benzophenone tetracarboxylic acid, and the like.

As the copolymerization component of the polycarbonate resin, in addition to the above, for example: and linear aliphatic 2-valent carboxylic acids such as adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and decanedicarboxylic acid.

As the components of the polycarbonate resin, various known components used as a terminal polymerization inhibitor in polymerization may be used as necessary within a range not impairing the effect of the present invention. Specific examples of the phenolic compound having a valence of 1 include phenol, p-cresol, p-tert-butylphenol, p-tert-octylphenol, p-cumylphenol, bromophenol, tribromophenol, and nonylphenol.

Examples of the carbonic acid diester compound used as a raw material of 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: polycarbonate resins obtained by an interfacial polycondensation method in which bisphenol a is reacted with phosgene, polycarbonate resins obtained by a melt polymerization method in which bisphenol a is reacted with diphenyl carbonate, and the like.

Particularly preferred matrix resins in the present invention are mixtures of acrylonitrile-styrene resins and polycarbonate resins. 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, and the ratio of the acrylonitrile-styrene resin: the weight ratio of the polycarbonate resin is preferably 50:50 to 1:99, more preferably 40:60 to 2:98, and further preferably 30:70 to 3: 97. Particularly, it is most preferably 25:75 to 5:95 in order to obtain excellent impact resistance.

(graft copolymer)

The graft copolymer in the present invention is a particulate graft copolymer comprising 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 present on the innermost side of the particles constituting the graft copolymer, and is composed of a polymer containing at least one monomer component selected from the group consisting of a (meth) acrylate, an aromatic vinyl compound, and a vinyl cyanide compound.

The (meth) acrylate is not particularly limited, and examples thereof include: alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and behenyl (meth) acrylate; aromatic ring-containing (meth) acrylates such as phenoxyethyl (meth) acrylate and benzyl (meth) acrylate; hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate; glycidyl (meth) acrylates such as glycidyl (meth) acrylate and glycidyl alkyl (meth) acrylate; alkoxyalkyl (meth) acrylates, and the like. In the present application, (meth) acrylic acid means a meaning in which acrylic acid and methacrylic acid are collectively expressed.

The aromatic vinyl compound is not particularly limited, and examples thereof include: styrene, alpha-methylstyrene, monochlorostyrene, dichlorostyrene, and the like.

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

In addition, a combination of vinylcarboxylic acids such as acrylic acid and methacrylic acid; vinyl halides such as vinyl chloride, vinyl bromide and chloroprene; vinyl acetate; olefins such as ethylene, propylene, butylene, and isobutylene.

The present invention can exhibit good color development in a thermoplastic resin containing a graft copolymer, but it is not necessary to adjust the difference between the refractive index of the seed and the refractive index of the matrix resin to be small, and the difference between the refractive indices is 0.07 or more. Thus, it is not necessary to select the monomer composition of the seed so that the refractive index difference is less than 0.035 as described in patent document 1. In particular, the monomer composition mainly composed of styrene 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, such a problem of reduction in productivity can be avoided without selecting the monomer composition of the seed disclosed in patent document 1. When the refractive index difference is less than 0.07, impact resistance, particularly impact resistance at low temperatures, is insufficient. The refractive index difference is preferably 0.08 or more, more preferably 0.085 or more, and still more preferably 0.09 or more. The upper limit of the refractive index difference is not particularly limited, and 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. In the case where the seed is formed of 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 in the entire seed. The refractive index of the matrix resin was measured in accordance with JIS K7142. In the case where 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) acrylate, specifically, a polymer obtained by polymerizing 80 to 100% by weight of (meth) acrylate and 0 to 20% by weight of an aromatic vinyl compound. The seed composed of the polymer having such a monomer composition can easily realize a refractive index difference of 0.07 or more between the seed and the matrix resin, and can improve impact resistance, particularly impact resistance at low temperatures. Further, the above-mentioned seeds can polymerize at a higher rate than the seeds mainly composed of styrene described in patent document 1, and therefore, productivity can be improved. The ratio of each monomer is a weight ratio of each monomer to the entire polymer constituting the seed. From the viewpoint of higher impact resistance and productivity, the (meth) acrylate is preferably 85% by weight or more and the aromatic vinyl compound is 15% by weight or less, more preferably 90% by weight or more and the aromatic vinyl compound is 10% by weight or less, and still more preferably 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) acrylate used in the seed, alkyl methacrylate is preferably used. By using an alkyl methacrylate for the seed, the seed can be made of a hard polymer, which is advantageous for improvement of color development. Among them, methyl methacrylate is particularly preferable.

The (meth) acrylate used in the seed may be only one or two or more kinds of alkyl methacrylate, or one or two or more kinds of alkyl methacrylate may be used in combination with one or two or more kinds of alkyl acrylate. The latter is preferable from the viewpoint of thermal stability described later. As the alkyl acrylate, butyl acrylate is particularly preferably used.

According to a particularly preferred embodiment of the present invention, the monomer composition of the seed-forming polymer is preferably 40 to 100% by weight of an alkyl methacrylate, 0 to 35% by weight of an alkyl acrylate, 0 to 10% by weight of an aromatic vinyl compound, and 0 to 15% by weight of another monomer having a copolymerizable double bond, more preferably 40 to 99.9% by weight of an alkyl methacrylate, 0.1 to 35% by weight of an alkyl acrylate, 0 to 10% by weight of an aromatic vinyl compound, and 0 to 15% by weight of another monomer having a copolymerizable double bond, still more preferably 40 to 99.8% by weight of an alkyl methacrylate, 0.1 to 35% by weight of an alkyl acrylate, 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, and still more preferably 51 to 96.9% by weight of an alkyl methacrylate, 3.1 to 29 wt% of alkyl acrylate, 0 to 10 wt% of aromatic vinyl compound and 0 to 10 wt% of other monomer having copolymerizable double bond. Within this range, the graft copolymer can have improved thermal stability and can withstand high-temperature molding. Specifically, alkyl methacrylate as a main component is likely to undergo zipper depolymerization (zipper depolymerization) during high-temperature molding and is likely to be thermally decomposed, but by containing alkyl acrylate and an aromatic vinyl compound within the above range, zipper depolymerization is likely to be suppressed, and thermal stability can be improved.

The seed may be composed of a polymer into which a crosslinked structure is not introduced, but is preferably composed of a polymer having a crosslinked structure. This makes it possible to form the seed from a hard polymer, which is advantageous for improving the color developability. The method for introducing the crosslinked structure is not particularly limited, and for example, when the seed is synthesized by polymerizing the monomer component, a crosslinkable monomer such as a polyfunctional monomer or a mercapto group-containing compound may be used.

Examples of the polyfunctional monomer include allyl alkyl (meth) acrylates such as allyl (meth) acrylate and allyl alkyl (meth) acrylate; allyloxyalkyl (meth) acrylates; polyfunctional (meth) acrylates having 2 or more (meth) acryloyl groups such as (poly) ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and tetraethylene glycol di (meth) acrylate; diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene, and the like. Allyl methacrylate, triallyl isocyanurate, butanediol di (meth) acrylate, and divinylbenzene are preferable, and allyl methacrylate is particularly preferable.

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

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

(core layer)

The core layer is a polymer layer formed on the surface of the seed particle, and is a layer made of a polymer having a crosslinked structure and containing at least one monomer component of acrylate. The 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 may cover at least a part of the surface of the seed particle, not the entire surface of the seed particle.

The polymer constituting the core layer is a polymer of a monomer component containing an acrylic ester. Specific examples of the acrylic ester include the acrylic esters listed for the seed. Particularly preferred are alkyl acrylates, more preferred is butyl acrylate. Further, monomers other than the acrylic acid ester may be used in combination or may not be used in combination. The other monomer may be suitably selected from the monomers listed for the seed. The weight ratio of the acrylate 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, based on the whole monomer components of the core layer.

The polymer constituting the core layer has a crosslinked structure. Specific examples of the polyfunctional monomer as a method for introducing the crosslinked structure are the same as those of the polyfunctional monomers described above. The total amount of the polyfunctional monomer used in the core layer is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, and still more preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the total of the monomer components (monomers other than the polyfunctional monomer) constituting the polymer of the core layer.

The core layer may be a single layer or 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 seed surface and a second core layer formed on the first core layer surface. The composition of the first core layer and the second core layer may be appropriately selected from the above-described compositions.

According to a preferred embodiment, the weight ratio of the second core layer to the entire core layer is preferably 1 to 50 wt%, more preferably 2 to 30 wt%, and further preferably 3 to 10 wt%, and the usage ratio of the multifunctional monomer in the second core layer is set to be higher than the usage ratio of the multifunctional monomer in the first core layer (that is, the crosslinking density of the second core layer is set to be higher than the crosslinking density of the first core layer). In such a core layer having a two-layer structure, the first core layer located inside provides impact resistance mainly. On the other hand, by adjusting the generation of the free polymer by the second core layer located outside and harder than the first core layer, the aggregation of the particles of the graft copolymer is suppressed, and the compatibility between the matrix resin and the graft copolymer can be improved. This improves the dispersibility of the graft copolymer in the matrix resin, and as a result, the color developability and impact resistance can be further improved.

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

From the viewpoint of color development, the weight ratio of the entire core layer in the graft copolymer is preferably 83% by weight or less. Within this range, further improvement in color developability is facilitated. More preferably 73% by weight or less, still more preferably 63% by weight or less, still more preferably 53% by weight or less, and particularly preferably 50% by weight or less. 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, and further preferably 40% by weight or more, from the viewpoint of imparting impact resistance.

In the graft copolymer of the present invention, the diameter of the particle composed of the seed and the core layer and the thickness of the core layer satisfy specific conditions, respectively. 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≤2×r2≤700 (1)

40≤r2-r1≤210 (2)

In each formula, r1 represents the radius (nm) of the seed. r2 represents the radius (nm) of a particle composed of the seed and the core layer (i.e., a particle before forming the shell layer and composed of the seed and the core layer). The state of 2 × r1 and 2 × 2 is the state of the latex of the seed or the state of the latex of the particle before forming the shell layer, which is formed from the seed and the core layer, and can be measured as the volume average particle diameter (nm) using MICROTRAC UPA150 manufactured by japan ltd.

The formula (1) defines the diameter (hereinafter also referred to as particle diameter) of the particles composed of the seed and the core layer to be 300 to 700 nm. When the diameter is less than 300nm, the impact resistance, particularly the impact resistance at low temperatures, is insufficient. The particle diameter is preferably 320nm or more, more preferably 340nm or more, further preferably 360nm or more, particularly preferably 380nm or more, and most preferably 400nm or more. In the present invention, the particle diameter up to the core layer is set to a relatively large level in this way, and the scattering principle of light is changed from rayleigh scattering to mie scattering, and therefore, excellent color developability can be achieved despite large particles. Since a favorable color-developing property is realized by changing the scattering principle to mie scattering in this way, it is presumed that the influence of the difference in refractive index between the seed and the matrix resin on the color-developing property is alleviated, and the favorable color-developing property can be realized without reducing the difference in refractive index as described in patent document 1. The upper limit of the particle size is not particularly limited, but is preferably 650nm or less, more preferably 600nm or less, further preferably 550nm or less, and further preferably 500nm or less, from the viewpoint of productivity.

The thickness of the core layer is defined by the formula (2) to be 40 to 210 nm. The core layer having a relatively thick thickness can achieve an excellent balance between impact resistance and color developability. The thickness of the core layer is preferably 45 to 200nm, more preferably 50 to 180nm, further preferably 55 to 160nm, further preferably 60 to 140nm, 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 particle. The shell layer improves the compatibility between the graft copolymer and the matrix resin, and the graft copolymer can be dispersed in the form of primary particles in the resin composition or a molded article formed from the resin composition. The polymer constituting the shell layer is preferably grafted with the polymer constituting the core layer. In addition, a part of the polymer constituting the shell layer may be grafted with the polymer constituting the seed. The shell layer may cover at least a part of the surface of the core layer without covering the entire surface of the core layer.

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

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

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

The weight ratio of the shell layer in the graft copolymer may be suitably determined in consideration of the weight ratio of the seed and the core layer, and may be, for example, 5 to 75 wt%, preferably 10 to 70 wt%, more preferably 20 to 65 wt%, further preferably 30 to 60 wt%, and particularly preferably 40 to 60 wt%, from the viewpoint of ensuring the ratio of the seed and the core layer and achieving compatibility with the matrix resin.

The shell layer may be formed of a polymer having a crosslinked structure, but is preferably formed of a polymer into which a crosslinked structure is not introduced. That is, the shell layer is preferably formed of a polymer synthesized without using a crosslinkable monomer such as a polyfunctional monomer. By not using a crosslinking 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 based on a conventional method, and specific examples are described below. In the production of the graft copolymer, a seed is first formed. The seed can be produced by, for example, emulsion polymerization, suspension polymerization, microsuspension polymerization, or the like, and the method described in, for example, international publication No. 2005/028546 can be used.

Next, a core layer is formed. The core layer can be formed by polymerizing the monomer component for the core layer in the presence of the seed by a known radical polymerization. In the case where the seed is obtained in the form of an emulsion, the polymerization of the monomer component for the core layer is preferably carried out by an emulsion polymerization method. In the case where 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.

Thereby forming a shell layer. The shell layer can be formed by polymerizing a monomer component for the shell layer by a known radical polymerization in the presence of particles formed of the seed and the core layer. When particles are obtained in the form of an emulsion, the particles being formed from seeds and a core layer and having a shell layer formed thereon, the polymerization of the monomer component for the shell layer is preferably carried out by an emulsion polymerization method, and the particles can be produced, for example, by the method described in international publication No. 2005/028546.

The emulsifier (dispersant) usable in the emulsion polymerization is not particularly limited, and an anionic surfactant, a nonionic surfactant, a cationic surfactant, an amphoteric surfactant, and the like can be used. Further, a dispersant such as polyvinyl alcohol, alkyl-substituted cellulose, polyvinyl pyrrolidone, polyacrylic acid derivative, or the like may be used. The anionic surfactant in the emulsifier is not particularly limited, and examples thereof include the following compounds: fatty acid soaps such as potassium laurate, potassium coconut oil fatty acid, potassium myristate, potassium oleate diethanolamine salt, sodium oleate, potassium palmitate, potassium stearate, sodium stearate, mixed fatty acid sodium soap, semi-cured tallow fatty acid sodium soap, castor oil potassium soap, etc.; alkyl sulfate ester salts such as sodium lauryl sulfate, sodium higher alcohol sulfate, triethanolamine lauryl sulfate, ammonium lauryl sulfate, sodium polyoxyethylene alkyl ether sulfate, triethanolamine polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfate, and sodium 2-ethylhexyl sulfate; sodium alkylbenzenesulfonates such as sodium dodecylbenzenesulfonate; sodium dialkyl sulfosuccinates such as sodium di-2-ethylhexyl sulfosuccinate; sodium alkylnaphthalene sulfonate; sodium alkyl diphenyl ether disulfonate; a potassium alkyl phosphate salt; phosphoric acid ester salts such as sodium polyoxyethylene lauryl ether phosphate; sodium salt of naphthalenesulfonic acid formalin condensate; a polycarboxylic acid type polymer anion; sodium acyl (tallow) methyl taurate; sodium acyl (coconut) methyl taurate; sodium cocoyl isethionate; alpha-sulfo fatty acid ester sodium salt; amide ether sodium sulfonate; oleoyl sarcosine; sodium lauroyl sarcosinate; rosin acid soaps, and the like.

The nonionic surfactant in the emulsifier is not particularly limited, and examples thereof include the following compounds: polyoxyethylene alkyl allyl ethers such as polyoxyethylene nonyl phenyl ether, polyoxyethylene oleyl ether and polyoxyethylene lauryl ether, polyoxyethylene sorbitan esters such as polyoxyethylene sorbitan monolaurate and polyoxyethylene sorbitan monostearate, polyoxyethylene fatty acid esters such as polyethylene glycol monolaurate, polyethylene glycol monostearate and polyethylene glycol monooleate, and oxyethylene/oxypropylene block copolymers.

The cationic surfactant in the emulsifier is not particularly limited, and examples thereof include the following compounds: alkylamine salts such as cocoamine acetate, stearylamine acetate, octadecylamine acetate and tetradecylamine acetate; quaternary ammonium salts such as lauryl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, hexadecyltrimethyl ammonium chloride, distearyl dimethyl ammonium chloride, alkylbenzyl dimethyl ammonium chloride, hexadecyltrimethyl ammonium chloride, behenyl trimethyl ammonium chloride, and the like.

The amphoteric surfactant in the emulsifier 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 diamino ethyl glycinate; an amido betaine; imidazoline; lauryl carboxymethylhydroxyethylimidazoleBetaine, and the like.

These emulsifiers (dispersants) may be used alone or in combination of two or more. The amounts of the emulsifiers used can be controlled to control r1 and r 2.

It is preferable to reduce the amount of the emulsifier (dispersant) used if the dispersion stability of the aqueous latex of polymer particles is not impaired. The higher the water solubility of the emulsifier (dispersant), the more preferable. 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 article can be easily prevented.

When the emulsion polymerization method is employed, a known initiator, that is, 2' -azobisisobutyronitrile, hydrogen peroxide, potassium persulfate, ammonium persulfate, or the like can be used as the thermal decomposition type initiator.

Further, organic peroxides such as t-butyl peroxyisopropyl carbonate, p-menthane hydroperoxide, cumene hydroperoxide, dicumyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, and t-hexyl peroxide; a redox initiator which is used in combination with a peroxide such as an inorganic peroxide such as hydrogen peroxide, potassium persulfate, or ammonium persulfate, a reducing agent such as sodium formaldehyde sulfoxylate or glucose which is used as necessary, a transition metal salt such as iron (II) sulfate which is used as necessary, a chelating agent such as disodium ethylenediaminetetraacetate which is used as necessary, a phosphorus-containing compound such as sodium pyrophosphate which is used as necessary, or the like.

When a redox type initiator system is used, polymerization can be carried out at a low temperature at which the peroxide is not substantially thermally decomposed, and it is preferable to set the polymerization temperature in a wide range. Among them, organic peroxides such as cumene hydroperoxide, dicumyl peroxide, and tert-butyl hydroperoxide are preferably used as the redox initiator. The amount of the initiator to be used, and the amount of the reducing agent/transition metal salt/chelating agent in the case of using a redox type initiator, can be used within a known range. In addition, when a monomer having 2 or more radical polymerizable double bonds is polymerized, a known chain transfer agent can be used within a known range. The surfactant may be additionally used, and this is also a known range.

The polymerization temperature, pressure, and deoxidation conditions during the polymerization may be within known ranges.

The radical copolymer used in the present invention preferably satisfies any one or more of the following characteristics (i) to (iii). In addition, any two or more of these characteristics are more preferably satisfied, and all three characteristics are more preferably satisfied.

(i) The Izod impact strength of 30kJ/m was measured under the following measurement conditions on a test piece 1 having a length of 63.5mm, a width of 12.7mm, a thickness of 3.2mm and a notch formed under the following test piece production conditions²The above. Preferably 35kJ/m²Above, more preferably 40kJ/m²Above, more preferably 45kJ/m²The above.

[ test piece production conditions ]:

(a) 74.4 parts by weight of an aromatic polycarbonate resin having a viscosity-average molecular weight of 19000 (Panlite L-1225WX, manufactured by Diniu corporation)

(b) Acrylonitrile-styrene resin (STYLACT 8701, Asahi Kasei K.K.) 16 parts by weight

(c) 9 parts by weight of the above graft copolymer

(d) 0.65 part by weight of a polycarbonate resin master batch (manufactured by Takara chemical Co., Ltd.) containing 30% by weight of carbon black

The mixture of (a) to (d) is kneaded by a twin-screw extruder (TEX 44SS, made by Nippon Steel Co., Ltd.) heated to a barrel temperature of 200 to 250 ℃ at a screw rotation speed of 100rpm to obtain extruded pellets. The pellets were dried at 80 ℃ for 5 hours by a hot air dryer, and a test piece was produced by an injection molding machine (FAS 100B, manufactured by FANUC corporation) at a molding temperature of 250 ℃ and a mold temperature of 70 ℃.

[ measurement conditions ]:

the Izod impact strength at 10 ℃ was measured by a method based on ASTM D256 standard.

(ii) The L value of a 3.2mm thick test piece 2 of a dumbbell type according to ASTM D638 produced under the test piece production conditions in (i) above was 20 or less as measured under the following measurement conditions. Preferably 15 or less, more preferably 13 or less, further preferably 11 or less, and particularly preferably 10 or less.

[ measurement conditions ]:

the reflection L value was measured by a color difference meter (model: SE-2000) manufactured by Nippon Denshoku industries Co., Ltd., according to JIS K8722. A

(iii) (ii) the MFR value measured under the following measurement conditions for the extruded pellets produced in the procedure of the test piece production conditions in (i) above is 21 or more. Preferably 23 or more, more preferably 24 or more, and still more preferably 25 or more.

[ measurement conditions ]:

the extruded pellets were dried at 80 ℃ for 5 hours by a hot air dryer according to JIS K7210A, and then the MFR value was measured under conditions of a measurement temperature of 260 ℃ and a load of 5 kg.

The thermoplastic resin composition of the present invention may contain, as required, any additives such as flame retardants, lubricants, antibacterial agents, mold release agents, nucleating agents, plasticizers, heat stabilizers, antioxidants, light stabilizers, ultraviolet stabilizers, compatibilizing agents, pigments, dyes, and inorganic additives. The compounding amount of each additive can be appropriately set by those skilled in the art.

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 kneader such as a single-screw or twin-screw extruder, a banbury mixer, a pressure kneader, or a mixing roll can be used for melt kneading.

The thermoplastic resin composition of the present invention can be produced and used for various applications, and can be used for architectural applications, electric/electronic applications, vehicle applications, and the like, for example, for electric/electronic applications such as computers, liquid crystal displays, projectors, PDAs, printers, copiers, facsimiles, video cameras, digital cameras, mobile phones (smart phones), mobile audio devices, game machines, DVD recorders, microwave ovens, electric cookers, and the like; building applications such as light-transmitting boards for roads, lighting windows, carports, lighting lenses, lighting covers, sizing for building materials, and doors; and automotive applications such as handlebars, shift levers, and vibration isolators, windows for electric cars, displays, lighting, and panels for driver's seats. Particularly, the resin composition is suitably used for automobile interior and exterior materials, exterior materials for electric appliances such as cellular phones and smart phones, interior and exterior materials for civil engineering and construction such as beds, windows, interior and exterior walls, lighting parts, and road signs, etc., by exhibiting excellent impact resistance and color development.

Examples

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

(refractive index of seed)

The refractive index of the seed is calculated based on the refractive index of each monomer used in forming the seed and the ratio of the monomers used. The details are as follows. The refractive index of methyl methacrylate (hereinafter MMA) was 1.494, the refractive index of butyl acrylate (hereinafter BA) was 1.463, the refractive index of styrene (hereinafter ST) was 1.595, and the refractive index of acrylonitrile (hereinafter AN) was 1.516, and the calculation was performed based on the following formula 1. The weight ratio of each monomer was defined as the weight ratio of each monomer to the whole amount of the seed.

(formula 1)

Refractive index of seed ═ refractive index of MMA × weight ratio of MMA/100) + (refractive index of BA × weight ratio of BA/100) + (refractive index of ST × weight ratio of ST/100) + (refractive index of AN × weight ratio of AN/100)

(refractive index of matrix resin)

The refractive index of each resin was measured using a 2mm plate of AS resin or polycarbonate resin (hereinafter referred to AS PC resin) by using an Abbe refractometer 2T manufactured by Atago in accordance with JIS K7142. When the matrix resin is a mixture, the calculation is performed based on the following formula 2.

(formula 2)

Refractive index of matrix resin (refractive index of AS resin × weight ratio of AS resin in the entire matrix resin/100) + (refractive index of PC resin × weight ratio of PC resin in the entire matrix resin/100)

(volume average particle diameter)

The volume average particle diameter is measured in the state of a latex of a seed or in the state of a latex of a particle before the seed and the core layer are formed and the shell layer is formed. As the measuring apparatus, MICROTRAC UPA150 manufactured by NIGHT-PROTOCOL, Inc. was used.

(polymerization conversion)

A part of the obtained latex was collected/precisely weighed, dried at 120 ℃ for 1 hour in a hot air dryer, and precisely weighed as a solid content. Then, the ratio of the results of the precise weighing before and after the drying was obtained as the solid content ratio in the latex. Finally, using the solid content ratio, the polymerization conversion was calculated by the following formula 3.

(formula 3)

Polymerization conversion (total weight of charged raw materials × solid content ratio-total weight of raw materials other than monomer)/weight of charged monomer × 100 (%)

(Izod impact Strength)

The mixtures of the examples and comparative examples were kneaded by a twin-screw extruder (TEX 44SS, made by Nippon Steel Co., Ltd.) heated to a cylinder temperature of 200 to 250 ℃ at a screw rotation speed of 100rpm, to obtain extruded pellets. The pellets were dried at 80 ℃ for 5 hours by a hot air dryer, and a test piece 1 having a length of 63.5mm, a width of 12.7mm, a thickness of 3.2mm and a notch was produced by an injection molding machine (FAS 100B, manufactured by FANUC corporation) at a molding temperature of 250 ℃ and a mold temperature of 70 ℃. The Izod impact strength at-30 ℃, 0 ℃,10 ℃ and 23 ℃ was measured for the test piece 1 obtained by a method based on ASTM D256.

(L value)

A dumbbell type test piece 2 having a thickness of 3.2mm in accordance with ASTM D638 was produced under the same conditions as those for the test piece 1 having an Izod impact strength. The obtained test piece 2 was measured for reflection L value by a color difference meter (model: SE-2000) manufactured by Nippon Denshoku industries Co., Ltd based on JIS K8722. The lower the L value, the darker black is shown, which means the better the color developability.

(MFR)

The extruded pellets produced under the conditions described above for Izod impact strength were dried at 80 ℃ for 5 hours by a hot air dryer according to JIS K7210A, and then the MFR value was measured under conditions of a measurement temperature of 260 ℃ and a load of 5 kg.

(examples 1 to 20 and comparative examples 1 to 7)

Graft copolymers composed of a seed, a core layer, and a shell layer were prepared based on the weight ratios described in the tables. In the production process, the volume average particle diameter of the seed (2 × r1) and/or the volume average particle diameter of the particles before the seed and the core layer were formed and the shell layer was formed (2 × r2) were measured, and the obtained numerical values of 2 × r2 and the calculated numerical values of r2 to r1 were shown in the tables.

As a representative graft copolymer, a specific order of manufacturing and obtaining the graft copolymer in example 6 is shown below. The procedure for producing the graft copolymer of comparative example 1 will be described separately below. The order of production/acquisition of the graft copolymer in examples other than example 6 and comparative examples other than comparative example 1 was based on the description below regarding example 6, but the amount of the emulsifier used was appropriately changed depending on the particle diameter of the seed, the thickness of the core layer, and the amount of the 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, for example, as described in the tables, but the kind of monomer used in each layer is the same as in example 6, and the use ratio of the monomer in each layer is the same as in example 6. However, in example 19 and comparative examples 6 and 7, the kind of the monomer used for the seed and the ratio of the monomer used were changed.

(production of graft copolymer of example 6)

180 parts by weight of deionized water and 0.023 parts by weight of a 0.5% by weight aqueous solution of dioctyl sodium sulfosuccinate were placed in a glass reactor equipped with a thermometer, a stirrer, a reflux condenser, a nitrogen inlet, and a device for adding monomers and emulsifiers, and the temperature was raised to 60 ℃ while stirring in a nitrogen stream.

To this, a sample was added, which was a mixture of 4.75 parts by weight of methyl methacrylate (hereinafter, MMA), 0.25 part by weight of butyl acrylate (hereinafter, BA), 0.25 part by weight of allyl methacrylate, and 0.015 part by weight of cumene hydroperoxide. Next, disodium ethylenediaminetetraacetate and ferrous sulfate were mixed at a mixing ratio of 4:1 and dissolved with deionized water to a concentration of 0.5 wt%, and 0.0033 parts by weight of the resulting mixed solution and 0.04 parts by weight of sodium formaldehyde sulfoxylate at a concentration of 5 wt% were added. In this state, the mixture was stirred for 60 minutes, and seed particles were formed at a polymerization conversion of 97%.

0.005 part by weight of cumene hydroperoxide was added thereto, and a mixture of 42.5 parts by weight of BA and 0.2 part by weight of allyl methacrylate was added thereto over 120 minutes. In the course of addition, 0.005 part by weight of cumene hydroperoxide was added depending on the degree of polymerization progress. After the addition, the mixture was stirred for 60 minutes while being heated to 65 ℃ to form a first core layer at a polymerization conversion rate of 98%.

To this, 0.0027 parts by weight of a mixed solution prepared by mixing disodium ethylenediaminetetraacetate at a mixing ratio of 4:1 with ferrous sulfate and dissolving the disodium ethylenediaminetetraacetate in deionized water to a concentration of 0.5% by weight was added, and a mixture of 2.5 parts by weight of BA, 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, stirring was carried out for 60 minutes, and a second core layer was formed at a polymerization conversion of 99%.

To this, 0.16 parts by weight of sodium formaldehyde sulfoxylate having a concentration of 5% by weight was added, and a sample prepared by mixing 12.7 parts by weight of acrylonitrile (hereinafter referred to as AN), 36.3 parts by weight of styrene (hereinafter referred to as ST), 1.0 part by weight of BA, 0.12 part by weight of t-dodecyl mercaptan, and 0.2 part by weight of t-butyl hydroperoxide was added over 180 minutes. After the addition, disodium ethylenediaminetetraacetate and ferrous sulfate were mixed at a mixing ratio of 4:1, and dissolved in deionized water to a concentration of 0.5 wt%, and 0.0051 part by weight of the resulting mixed solution and 0.05 part by weight of sodium formaldehyde sulfoxylate at a concentration of 5 wt% were added and stirred for 10 minutes. Then, 0.05 part by weight of t-butyl hydroperoxide was added thereto, and the mixture was stirred for 20 minutes. Then, 0.05 part by weight of t-butyl hydroperoxide was added thereto, and the mixture was stirred for 40 minutes to form a shell at a polymerization conversion of 99.5%. This gave a latex of a graft copolymer comprising a seed, a core layer (first core layer and second core layer), and a shell layer.

(production of graft copolymer of comparative example 1)

155 parts by weight of deionized water, 0.48 part by weight of boric acid, 0.05 part by weight of sodium carbonate, and 0.016 part by weight of a 1.0% by weight aqueous polyoxyethylene lauryl ether phosphate solution were placed in a glass reactor equipped with a thermometer, a stirrer, a reflux condenser, a nitrogen inlet, and a device for adding a monomer and an emulsifier, and the temperature was raised to 50 ℃ while stirring in a nitrogen stream.

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

To this was added 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 over 50 minutes. In the course of addition, 0.01 part by weight of a 2% strength by weight aqueous sodium hydroxide solution was added as appropriate. After the mixture was added, the mixture was stirred for 15 minutes, and 0.015 part 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 thereto, and the mixture was further stirred for 30 minutes, whereby a shell layer was formed at a polymerization conversion of 100%. This gave a latex of a graft copolymer composed only of a core layer and a shell layer.

(obtaining of white resin powder of graft copolymer)

500 parts by weight of deionized water and 5 parts by weight of a 25% by weight aqueous calcium chloride solution were heated to 70 ℃ and a latex of a graft copolymer was added thereto to obtain a slurry containing coagulated latex particles. Then, the coagulated latex particle slurry was heated to 95 ℃ and dehydrated and dried to obtain a graft copolymer in the form of white resin powder.

(production of thermoplastic resin composition)

The white resin powder of the obtained graft copolymer, an aromatic polycarbonate resin (Panlite L-1225WX, product of teiman corporation) having a viscosity average molecular weight of 19000, an acrylonitrile-styrene resin (STYLACT 8701, product of asahi chemical corporation), and a polycarbonate resin master batch (product of takawa chemical corporation) containing 30 wt% of carbon black were mixed in the blending parts shown in the tables, and the obtained mixture was measured for Izod impact strength, MFR, and L value under the above conditions, and the results thereof are shown in the tables.

The thermoplastic resin compositions obtained in the respective examples of Table 1 had an Izod impact strength of 30kJ/m measured at 10 ℃²Above that, the Izod impact strength measured at-30 ℃ is 14kJ/m²Above and having an L value of 20 or less, it is found that both impact resistance and color developability are excellent. On the other hand, the thermoplastic resin composition obtained in comparative example 1 using a graft copolymer without a seed had an L value of 21, and it was found that the color developability was poor. Furthermore, the thermoplastic resin compositions obtained in comparative examples 2 to 4 using the graft copolymer having a thickness of r2 to r1 of less than 40nm as the core layer had Izod impact strength of less than 30kJ/m measured at 10 ℃²It was found that the impact resistance was poor. Further, it is understood that the thermoplastic resin composition obtained in comparative example 5 using a graft copolymer having a diameter of 2 × r2 smaller than 300nm as particles composed of a seed and a core layer has a low Izod impact strength measured at-30 ℃ and is inferior in impact resistance at low temperature.

[ Table 2]

Examples 13 to 16 in Table 2 each showed good impact resistance and color development properties, with the number of blending parts of the graft copolymer changed. In examples 17 and 18, the resin composition in the matrix resin was changed, but both of them exhibited good impact resistance and color development.

[ Table 3]

It is understood that in example 19 of table 3, the difference between the refractive index of the seed and the refractive index of the matrix resin is 0.07, and therefore, good impact resistance and color development are exhibited, while in comparative example 6, the difference between the refractive indices is 0.06, and therefore, the Izod impact strength measured at-30 ℃ is low, and the impact resistance at low temperature is poor.

[ Table 4]

Example 20 and comparative example 7 in table 4 have the resin composition in the matrix resin changed. In example 20, the difference between the refractive index of the seed and the refractive index of the matrix resin was set to 0.073, and in comparative example 7, the difference between the refractive indices was set to 0.03, but in example 20, impact resistance was better than in comparative example 7.