阅读说明：本技术 热塑性树脂组合物及其成型品 (Thermoplastic resin composition and molded article thereof ) 是由 上田隆志 小林正典 佐藤大辅 于 2020-03-23 设计创作，主要内容包括：本发明涉及一种树脂组合物,是混配有聚碳酸酯树脂(I)、特定的接枝共聚物(II)、乙烯基系共聚物(III)、无机填充材料(IV)、磷酸酯系化合物(V)的热塑性树脂组合物,乙烯基系共聚物(III)的重均分子量为110,000以下,乙烯基系共聚物(III)与聚碳酸酯树脂(I)的熔体流动速率之比为7以上且12以下,磷酸酯系化合物(V)的混配量相对于(I)～(IV)的合计100重量份为1～10重量份。(The present invention relates to a thermoplastic resin composition comprising a polycarbonate resin (I), a specific graft copolymer (II), a vinyl copolymer (III), an inorganic filler (IV), and a phosphate ester compound (V), wherein the weight average molecular weight of the vinyl copolymer (III) is 110,000 or less, the ratio of the melt flow rates of the vinyl copolymer (III) and the polycarbonate resin (I) is 7 or more and 12 or less, and the amount of the phosphate ester compound (V) to be compounded is 1 to 10 parts by weight based on 100 parts by weight of the total of (I) to (IV).)

1. A thermoplastic resin composition comprising a polycarbonate resin (I), a graft copolymer (II), a vinyl copolymer (III), an inorganic filler (IV) and a phosphate ester compound (V),

the graft copolymer (II) is at least one of a graft copolymer (II-1) and a graft copolymer (II-2), wherein the graft copolymer (II-1) is obtained by graft-polymerizing a monomer mixture containing at least an aromatic vinyl monomer and a vinyl cyanide monomer in the presence of a diene rubber polymer, and the graft copolymer (II-2) is obtained by graft-polymerizing a monomer mixture containing at least an aromatic vinyl monomer and a vinyl cyanide monomer in the presence of an acrylic rubber polymer obtained by polymerizing an acrylate monomer and a polyfunctional monomer,

The weight-average molecular weight of the vinyl copolymer (III) is 110,000 or less,

melt flow Rate III of the vinyl copolymer (III) at 240 ℃ under 10kg_MFMelt flow rate I with polycarbonate resin (I) at 240 ℃ under a load of 10kg_MFRatio of (III)_MF/I_MFIs 7 or more and 12 or less, III_MFAnd I_MFThe units of (a) are all g/10 minutes,

the amount of the phosphate ester compound (V) is 1 to 10 parts by weight based on 100 parts by weight of the total of (I) to (IV).

2. The thermoplastic resin composition according to claim 1, wherein the inorganic filler (IV) is at least one of talc and wollastonite.

3. A molded article obtained by molding the thermoplastic resin composition according to claim 1 or 2.

Technical Field

The present invention relates to a thermoplastic resin composition having excellent flowability, in which appearance defects (Silver appearance) due to Silver streaks (Silver flow) in a molded article are suppressed, and to a molded article thereof.

Background

Polycarbonate resins are widely used in various fields including the automobile field, the household electrical appliance field, the OA equipment field, and the building material field because of their excellent heat resistance and impact resistance. On the other hand, rubber-reinforced styrene resins represented by ABS resins have excellent processability and mechanical properties, and therefore, are used as molding materials for various structural members in a wide range of fields such as automobile fields, household electric appliance fields, OA equipment fields, and the like.

Since a polycarbonate resin is inferior to a rubber-reinforced styrene resin in molding processability and secondary processability in injection molding, it is common to alloy a polycarbonate resin and a rubber-reinforced styrene resin by melt-mixing them in order to compensate for the disadvantages of the polycarbonate resin. In particular, in the automobile field, dimensional stability is required in addition to heat resistance, impact resistance, moldability and the like, and for improvement thereof, blending of an inorganic filler such as talc has been attempted.

However, a silicate compound-based inorganic filler such as a rubber-reinforced styrene resin or talc produced through an emulsion polymerization/acid coagulation/neutralization step may be alkaline, and when it is blended in a polycarbonate resin, there is a problem that a molded article having poor appearance such as silver streaks due to alkaline decomposition of the resin occurs.

As a conventional technique for blending a silicate compound-based inorganic filler such as talc into a polycarbonate resin/rubber-reinforced styrene resin alloy, for example, patent document 1 discloses a resin composition containing an aromatic polycarbonate resin, a styrene-based resin, a phosphate ester-based compound, and an inorganic filler in a specific composition.

Patent document 2 discloses a resin composition containing an aromatic polycarbonate, an ABS resin, a phosphate ester compound, a fluoropolymer, and talc in a specific composition.

Patent document 3 discloses a resin composition prepared by blending an aromatic polycarbonate resin, a styrene resin, a phosphate ester compound, and talc having a specific molecular weight in a specific composition.

Further, patent document 4 discloses a resin composition prepared by blending an aromatic polycarbonate resin, a styrene resin, a polyester resin, and talc in a specific composition.

Patent document 5 discloses an ABS resin produced by emulsion polymerization.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2003-138122

Patent document 2: japanese patent laid-open publication No. 2015-28135

Patent document 3: japanese patent laid-open No. 2001 and 49106

Patent document 4: international publication No. 2018/083975

Patent document 5: japanese patent laid-open No. 2012 and 177088

Disclosure of Invention

Problems to be solved by the invention

However, the resin composition described in patent document 1 has a problem that the effect is not sufficient and the fluidity is also problematic although the silver appearance is improved to some extent.

Patent document 2 does not describe improvement in the appearance of silver due to decomposition of the resin, and the effect is insufficient.

Patent document 3 also does not describe improvement of the silver appearance due to decomposition of the resin, and the effect thereof is not sufficient.

The technique described in patent document 4 is effective for crystalline resins in terms of improvement of defects in silver appearance caused by inorganic fillers, but is not sufficiently effective for defects in silver appearance caused by rubber-reinforced styrene resins obtained by emulsion polymerization.

The technique described in patent document 5 is also insufficient in the effect of improving the silver appearance.

Accordingly, an object of the present invention is to provide a thermoplastic resin composition and a molded article having excellent flowability, in which the silver appearance of the molded article is suppressed.

Means for solving the problems

As a result of intensive studies to solve the above problems, the present inventors have found that a thermoplastic resin composition having excellent flowability and capable of suppressing the silver appearance of a molded article can be obtained by compounding a polycarbonate resin, a graft copolymer, a vinyl copolymer, an inorganic filler, and a phosphate ester compound in a specific composition and controlling the melt viscosity ratio of the vinyl copolymer to the polycarbonate, and have completed the present invention.

That is, the present invention is constituted by the following (1) to (3).

(1) A thermoplastic resin composition comprising a polycarbonate resin (I), a graft copolymer (II), a vinyl copolymer (III), an inorganic filler (IV) and a phosphate ester compound (V),

the graft copolymer (II) is at least one of a graft copolymer (II-1) and a graft copolymer (II-2), the graft copolymer (II-1) is obtained by graft-polymerizing a monomer mixture containing at least an aromatic vinyl monomer and a vinyl cyanide monomer in the presence of a diene rubber polymer, the graft copolymer (II-2) is obtained by graft-polymerizing a monomer mixture containing at least an aromatic vinyl monomer and a vinyl cyanide monomer in the presence of an acrylic rubber polymer obtained by polymerizing an acrylate monomer and a polyfunctional monomer,

the weight-average molecular weight of the vinyl copolymer (III) is 110,000 or less,

melt flow Rate (III) of vinyl copolymer (III)_MF) [ g/10 min ]](240 ℃, 10kg) melt flow Rate (I) with polycarbonate resin (I)_MF) [ g/10 min ]](temperature: 240 ℃ C., load: 10kg) ((III)_MF)/(I_MF) ) is 7 or more and 12 or less,

The amount of the phosphate ester compound (V) is 1 to 10 parts by weight based on 100 parts by weight of the total of (I) to (IV).

(2) The thermoplastic resin composition according to the item (1), wherein the inorganic filler (IV) is at least one of talc and wollastonite.

(3) A molded article obtained by molding the thermoplastic resin composition according to the above (1) or (2).

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the silver appearance of the molded article can be suppressed, and the yield can be improved.

Further, the thermoplastic resin of the present invention has high fluidity, and therefore, a large-sized molded product, a molded product having a complicated shape, and a thin-walled molded product, which have not been conventionally moldable, can be obtained by injection molding. Therefore, not only can the product be made large and the shape be complicated, but also the product cost can be reduced by making the thickness thin.

Drawings

Fig. 1(a) and 1(b) of fig. 1 are explanatory views schematically showing a square flat plate used in the embodiment, fig. 1(a) is a plan view, and fig. 1(b) is a sectional view taken along line a-a of fig. 1 (a).

Detailed Description

The thermoplastic resin composition and the molded article thereof of the present invention will be specifically described below.

[ polycarbonate resin (I) ]

The polycarbonate resin (I) used in the present invention is a resin having a repeating structural unit represented by the following general formula (1).

(wherein Z represents a substituted or unsubstituted alkylene group having 2 to 5 carbon atoms, cyclohexylene group, oxygen atom, sulfur atom or sulfonyl group₁、R₂、R₃、R₄The hydrogen atom or the alkyl group having 1 to 6 carbon atoms may be the same or different. ).

In the present invention, Z is preferably isopropylidene, R₁～R₄Preferably a hydrogen atom.

The polycarbonate resin (I) is obtained by reacting an aromatic dihydroxy compound exemplified by 2, 2-bis (4-hydroxyphenyl) propane and 2, 2-bis (3, 5-dimethyl-4-hydroxyphenyl) propane with a carbonate precursor exemplified by phosgene.

In the thermoplastic resin composition of the present invention, the content of the polycarbonate resin (I) is preferably in the range of 60 to 90% by weight, more preferably 65 to 85% by weight, and still more preferably 70 to 80% by weight, based on 100% by weight of the total of the contents of the polycarbonate resin (I), the graft copolymer (II), the vinyl copolymer (III), and the inorganic filler (IV). When the amount of the polycarbonate resin (I) added is less than 60% by weight, the flowability is excellent, but the impact resistance and heat resistance may be lowered. On the other hand, when the amount exceeds 90% by weight, although the impact resistance and heat resistance are excellent, the flowability at the time of injection molding is insufficient, and an unmoldable product may be produced.

In the present invention, the viscosity average molecular weight (M) of the polycarbonate resin (I)_V) The content is not particularly limited, but is preferably 10,000 or more and 21,000 or less, more preferably 12,000 or more and 20,000 or less, and most preferably 15,000 or more and 18,000 or less. At M_VWhen the content is 10,000 or more, mechanical properties such as impact resistance and heat resistance tend to be improved, and when the content is 21,000 or less, fluidity tends to be improved and the appearance of the molded article tends to be improved, which is preferable.

In the present invention, in the case of the present invention,viscosity average molecular weight (M) of polycarbonate resin (I)_V) The method can be determined as follows. First, from a solution (concentration c is 0.7) obtained by dissolving 0.7g of polycarbonate resin (I) in 100ml of methylene chloride at 20 ℃, using an ostwald viscometer, a specific viscosity (η) calculated by the following formula was obtained_SP)。

Specific viscosity (. eta.)_SP)＝(t-t₀)/t₀

[t₀The number of seconds of methylene chloride falling, and t is the number of seconds of sample solution falling]

Then, the specific viscosity (. eta.) can be determined_SP) The viscosity average molecular weight M was calculated by the following Schnell formula_V。

η_SP/c＝[η]+0.45×[η]²c (where eta)]To intrinsic viscosity)

[η]＝1.23×10^-4M_V ^0.83

The graft copolymer (II) constituting the thermoplastic resin composition of the present invention is at least one of a graft copolymer (II-1) and a graft copolymer (II-2), the graft copolymer (II-1) is obtained by graft polymerizing a monomer mixture containing at least an aromatic vinyl monomer (B) and a vinyl cyanide monomer (C) in the presence of a diene rubber polymer (a1), and the graft copolymer (II-2) is obtained by graft polymerizing a monomer mixture containing an aromatic vinyl monomer (B) and a vinyl cyanide monomer (C) in the presence of an acrylic rubber polymer (hereinafter, sometimes referred to as "acrylic rubber polymer (a 2)") obtained by copolymerizing an acrylate monomer and a polyfunctional monomer.

[ graft copolymer (II-1) ]

As the diene rubber polymer (A1) that can be used in the graft copolymer (II-1), those having a glass transition temperature of 0 ℃ or lower are suitable, and the lower limit thereof is practically about-80 ℃. Examples of the diene rubber polymer that can be used include polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, styrene-butadiene block copolymer, butyl acrylate-butadiene copolymer and the like, and among them, polybutadiene is preferably used.

The weight-average particle diameter of the diene rubber polymer (A1) is not particularly limited, but is preferably 100 to 1200nm, more preferably 200 to 1200 nm. When a diene rubber polymer (A1) having a weight average particle diameter of less than 100nm is used, impact resistance may be lowered, and when a diene rubber polymer having a weight average particle diameter of more than 1200nm is used, fluidity may be lowered.

In addition, from the viewpoint of both impact resistance and fluidity, the diene rubber polymer (A1) is preferably a combination of particles having a weight average particle diameter of 200 to 400nm and particles having a weight average particle diameter of 450 to 1200nm, more preferably a combination of particles having a weight average particle diameter of 280 to 400nm and particles having a weight average particle diameter of 600 to 1200nm, and still more preferably a combination of particles having a weight average particle diameter of 320 to 380nm and particles having a weight average particle diameter of 700 to 1100 nm.

When 2 kinds of diene rubber-based polymers (a1) having different particle shapes are used, the weight ratio of the particles having a low particle diameter to the particles having a high particle diameter is preferably 90: 10-50: 50, more preferably 80: 20-60: 40, more preferably 75: 25-65: 35, in the above range.

The weight average particle size of the diene rubber polymer (a1) can be measured by the sodium alginate method described in "Rubbaer Age vol.88p.484-490 (1960) by e.schmidt, p.h. biddison" (particle size at 50% cumulative weight fraction is determined from the ratio of the amount of sodium alginate concentration and the cumulative weight fraction of the sodium alginate concentration).

The weight fraction of the diene rubber polymer (A1) in the graft copolymer (II-1) is preferably 40 to 65% by weight, more preferably 40 to 60% by weight, and still more preferably 40 to 50% by weight. It is preferable that the weight fraction is 40% by weight or more because the impact resistance is improved, and 65% by weight or less because the fluidity is improved.

Examples of the aromatic vinyl monomer (B) contained in the monomer mixture include styrene, α -methylstyrene, vinyltoluene, o-ethylstyrene, p-methylstyrene, chlorostyrene, and bromostyrene, and styrene is particularly preferably used.

Examples of the vinyl cyanide-based monomer (C) contained in the monomer mixture include acrylonitrile, methacrylonitrile, and ethacrylonitrile, and acrylonitrile is particularly preferably used.

In addition, other vinyl monomers copolymerizable with the aromatic vinyl monomer (B) and the vinyl cyanide monomer (C) may be contained in the monomer mixture to such an extent that the effect of the present invention is not lost. Specific examples of the other vinyl monomers include N-phenylmaleimide, N-methylmaleimide, and methyl methacrylate, and these monomers can be selected according to the purpose, and they can be used alone or in combination of two or more. In addition, if the intention is to further improve heat resistance and flame retardancy, N-phenylmaleimide is preferable. In addition, if importance is attached to the improvement of hardness, methyl methacrylate is preferably used.

The weight fraction of the aromatic vinyl monomer (B) in the graft copolymer (II-1) is preferably 26 to 43% by weight, more preferably 30 to 41% by weight, and particularly preferably 35 to 41% by weight. When the weight fraction of the aromatic vinyl monomer (B) is 26% by weight or more, coloration tends to be less likely, while when the weight fraction of the aromatic vinyl monomer (B) is 43% by weight or less, graft polymerization tends to proceed easily, the graft ratio is improved, and the impact resistance is improved.

The weight fraction of the vinyl cyanide monomer (C) in the graft copolymer (II-1) is preferably 9 to 17% by weight, more preferably 10 to 16% by weight, and still more preferably 12 to 16% by weight. When the weight fraction of the vinyl cyanide monomer (C) is 9% by weight or more, graft polymerization tends to proceed easily, the graft ratio is improved, and impact resistance tends to be improved, and when the weight fraction of the vinyl cyanide monomer (C) is 17% by weight or less, coloring tends to be less likely.

The graft ratio of the graft copolymer (II-1) is not particularly limited. The graft ratio is preferably 7 to 30%, more preferably 20 to 28%, and still more preferably 22 to 26% in view of the balance between impact resistance and fluidity. The graft ratio (%) is represented by the following formula.

Graft ratio (%) [ amount of vinyl polymer graft-polymerized with diene rubber polymer ]/[ rubber content of graft copolymer ] × 100.

As the polymerization method of the graft copolymer (II-1), any method such as emulsion polymerization, suspension polymerization, continuous bulk polymerization, solution continuous polymerization and the like can be used, and 2 or more kinds thereof can be combined. The emulsion polymerization method is most preferable because the temperature control during polymerization is easy.

Examples of the graft copolymer (II-1) include an acrylonitrile/butadiene/styrene graft copolymer (ABS resin), a methyl methacrylate/butadiene/styrene graft copolymer (MBS resin), a methyl methacrylate/acrylonitrile/butadiene/styrene graft copolymer (MABS resin), and the like. Among them, acrylonitrile/butadiene/styrene graft copolymer (ABS resin) is preferable.

[ graft copolymer (II-2) ]

The thermoplastic resin composition comprising the graft copolymer (II-2) is excellent in weather resistance.

The acrylic ester monomer (a) constituting the acrylic rubber polymer (a2) obtained by copolymerizing the acrylic ester monomer (a) and the polyfunctional monomer (b) which can be used for the graft copolymer (II-2) is preferably an acrylic ester monomer having an alkyl group having 1 to 10 carbon atoms, and examples thereof include methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate, and octyl acrylate. More than 2 of them may be used. Among them, n-butyl acrylate is preferable.

The polyfunctional monomer (b) constituting the acrylic rubber polymer (a2) is not particularly limited as long as it has 2 or more functional groups, and examples of the functional groups include groups having a carbon-carbon double bond such as allyl group and (meth) acryloyl group. Examples of the polyfunctional monomer (b) include allyl compounds such as allyl acrylate, allyl methacrylate, diallyl maleate, triallyl cyanurate, and triallyl isocyanurate, and di (meth) acrylate compounds such as divinylbenzene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and propylene glycol dimethacrylate. More than 2 of them may be used. Among them, allyl methacrylate is preferable because the gel swelling degree of the acrylic rubber-like polymer (a2) in toluene and the graft ratio of the graft copolymer (II-2) described later can be easily adjusted to desired ranges.

The acrylic rubber polymer (A2) in the present invention is preferably obtained by copolymerizing 97 to 99.5 wt% of the acrylate monomer (a) and 3 to 0.5 wt% of the polyfunctional monomer (b) with respect to 100 wt% of the total of the acrylate monomer (a) and the polyfunctional monomer (b). When the acrylate monomer (a) is 97% by weight or more and the polyfunctional monomer (b) is 3% by weight or less, the gel swell of the acrylic rubber polymer (a2) in toluene described later tends to increase, and the graft ratio of the graft copolymer (II-2) described later tends to decrease. As a result, the thermoplastic resin composition has improved flowability, and can have a structure in which the particles of the graft copolymer (II-2) are aggregated, so that the impact strength and the surface impact property of the molded article are improved.

More preferably, the amount of the acrylate monomer (a) is 98% by weight or more and the amount of the polyfunctional monomer (b) is 2% by weight or less, and still more preferably, the amount of the acrylate monomer (a) exceeds 98.5% by weight and the amount of the polyfunctional monomer (b) is less than 1.5% by weight.

On the other hand, when the acrylate monomer (a) is 99.5% by weight or less and the polyfunctional monomer (b) is 0.5% by weight or more, the graft ratio of the graft copolymer (II-2) described later is improved, and the impact strength and the surface impact property of the molded article are improved, which is preferable.

The acrylate monomer (a) is more preferably 99.3% by weight or less, and still more preferably 99.0% by weight or less. The polyfunctional monomer (b) is more preferably 0.7% by weight or more, and still more preferably 1.0% by weight or more.

As a polymerization method of the acrylic rubber polymer (a2), any method such as emulsion polymerization, suspension polymerization, continuous bulk polymerization, solution continuous polymerization, or the like can be used, and 2 or more kinds thereof can be combined. Among them, the emulsion polymerization method or the bulk polymerization method is preferable. The emulsion polymerization method is most preferable because the volume average particle diameter can be easily adjusted to a desired range by heat removal during polymerization.

The emulsifier used in the emulsion polymerization method is not particularly limited, and various surfactants can be used. As the surfactant, anionic surfactants such as carboxylate type, sulfate type, and sulfonate type surfactants are preferably used. More than 2 of them may be used.

Specific examples of the anionic surfactant include caprylate, caprate, laurate, myristate, palmitate, stearate, oleate, linoleate, linolenate, rosinate, behenate, and behenate Acid salts, castor oil sulfate salts, lauryl alcohol sulfate salts, dodecylbenzene sulfonate salts, alkylnaphthalene sulfonate salts, alkyldiphenyl ether disulfonate salts, naphthalene sulfonate condensate salts, dialkyl sulfosuccinate salts, polyoxyethylene lauryl sulfate salts, polyoxyethylene alkyl ether sulfate salts, polyoxyethylene alkylphenyl ether sulfate salts, and the like. Examples of the salt include alkali metal salts such as ammonium salt, sodium salt, lithium salt, and potassium salt.

The initiator used for the polymerization is not particularly limited, but preferably cumene hydroperoxide as a peroxide, azobisisobutyronitrile as an azo compound, potassium persulfate as a persulfate, or the like, and 2 or more kinds of these initiators can be used.

The graft copolymer (II-2) used in the present invention is obtained by graft polymerizing a monomer mixture containing at least an aromatic vinyl monomer (B) and a vinyl cyanide monomer (C) in the presence of the acrylic rubbery polymer (a 2). That is, the graft copolymer (II-2) is a copolymer obtained by graft polymerizing a monomer mixture containing an aromatic vinyl monomer and a vinyl cyanide monomer with the acrylic rubber polymer (a 2).

The compounding amount of the acrylic rubber polymer (a2) is preferably 20 parts by weight or more, and more preferably 30 parts by weight or more, based on 100 parts by weight of the total of the acrylic rubber polymer (a2) and the monomer mixture constituting the graft copolymer (II-2). On the other hand, the compounding amount of the acrylic rubber polymer (a2) is preferably 70 parts by weight or less, and more preferably 60 parts by weight or less. The amount of the monomer mixture is preferably 30 parts by weight or more, and more preferably 40 parts by weight or more. On the other hand, the compounding amount of the monomer mixture is preferably 80 parts by weight or less, more preferably 70 parts by weight or less.

The monomer mixture constituting the graft copolymer (II-2) contains the aromatic vinyl monomer (B) and the vinyl cyanide monomer (C), and may further contain a monomer copolymerizable therewith as required.

Examples of the aromatic vinyl monomer (B) include styrene, α -methylstyrene, p-methylstyrene, m-methylstyrene, o-methylstyrene and t-butylstyrene. More than 2 of them may be used. Among them, styrene is preferable.

Examples of the vinyl cyanide monomer (C) include acrylonitrile, methacrylonitrile, and ethacrylonitrile. More than 2 of them may be used. Among them, acrylonitrile is preferable.

The other copolymerizable monomer is not particularly limited as long as the effect of the present invention is not impaired, but is preferably, for example, methyl (meth) acrylate as an unsaturated carboxylic acid alkyl ester monomer, methacrylic acid as an unsaturated fatty acid, acrylamide, methacrylamide or N-phenylmaleimide as a maleimide monomer, and 2 or more of them may be used.

The mixing ratio of the monomer mixture is preferably 60 to 80 wt% of the aromatic vinyl monomer (B), 20 to 40 wt% of the vinyl cyanide monomer (C), and 0 to 20 wt% of the other copolymerizable monomer, based on 100 wt% of the total amount of the monomer mixture.

The graft ratio (. beta.) of the graft copolymer (II-2) is preferably 5 to 40%. The graft ratio (. beta.) is an index indicating the compatibility of the graft copolymer (II-2), and when the graft ratio is 5% or more, the compatibility of the graft copolymer (II-2) in the thermoplastic resin composition is improved, and the impact strength and the surface impact property of the molded article can be further improved. More preferably 8% or more. On the other hand, if the graft ratio is 40% or less, the particles of the graft copolymer (II-2) tend to aggregate together in the thermoplastic resin composition, and the impact strength and the surface impact property of the molded article can be further improved. More preferably 35% or less, and still more preferably 30% or less.

The graft ratio (. beta.) of the graft copolymer (II-2) can be determined by the following method. First, 100ml of acetonitrile was added to a predetermined amount (m; about 1.5g) of the graft copolymer (II-2) which had been vacuum-dried at 80 ℃ for 3 hours, and the mixture was refluxed in a hot water bath at 70 ℃ for 3 hours. After the solution was centrifuged at 9000rpm for 40 minutes, insoluble matter was filtered, and the insoluble matter was dried under vacuum at 80 ℃ for 5 hours to measure the weight (n; unit g). The graft ratio (. beta.) was calculated from the following equation. Here, L is the rubber content (wt%) of the graft copolymer (i.e., the content (wt%) of the acrylic rubbery polymer (A2) in the graft copolymer (II-2)).

The graft ratio (%) { [ (n) - ((m) × L/100) ]/[ (m) × L/100] } × 100.

The graft ratio of the graft copolymer (II-2) can be adjusted to a desired range by using the above-mentioned acrylic rubber polymer (A2) and adjusting the amount of a chain transfer agent, an emulsifier, an initiator and the like used for polymerization.

As the polymerization method of the graft copolymer (II-2), any method such as emulsion polymerization, suspension polymerization, continuous bulk polymerization, solution continuous polymerization and the like can be used, and 2 or more kinds of them can be combined. The emulsion polymerization method is most preferable because the temperature control during polymerization is easy.

Examples of the emulsifier used in the emulsion polymerization method of the graft copolymer (II-2) include emulsifiers exemplified as emulsifiers used in the emulsion polymerization method of the acrylic rubber polymer (A2). The polymerization initiator used for the polymerization of the graft copolymer (II-2) may be a polymerization initiator exemplified as the initiator used for the polymerization of the acrylic rubber polymer (A2).

For the purpose of adjusting the degree of polymerization and the graft ratio of the graft copolymer (II-2), a chain transfer agent may be used. Specific examples of the chain transfer agent include mercaptans such as n-octyl mercaptan, t-dodecyl mercaptan, n-tetradecyl mercaptan and n-octadecyl mercaptan, terpenes such as terpinolene, and the like. More than 2 of them may be used. Among them, n-octyl mercaptan and t-dodecyl mercaptan are preferably used.

From the viewpoint of adjusting the graft ratio of the graft copolymer (II-2) to the above-mentioned preferable range, it is preferable to use 0.05 to 0.5 parts by weight of the chain transfer agent, 0.5 to 5 parts by weight of the emulsifier, and 0.1 to 0.5 parts by weight of the initiator, based on 100 parts by weight of the total of the acrylic rubber polymer (A2) and the monomer mixture in the polymerization of the graft copolymer (II-2).

Examples of the graft copolymer (II-2) include an acrylonitrile/acrylic rubber polymer/styrene graft copolymer (ASA resin), a methyl methacrylate/acrylic rubber polymer/styrene graft copolymer (MSA resin), a methyl methacrylate/acrylonitrile/acrylic rubber polymer/styrene graft copolymer (MASA resin), and the like. Among them, acrylonitrile/acrylic rubbery polymer/styrene graft copolymer (ASA resin) is preferable.

The graft copolymer (II) used in the present invention tends to be alkaline depending on the production method employed. Further, in the present invention, when the graft copolymer (II) exhibiting basicity is used, a more significant effect is brought about.

For example, in the present invention, the graft copolymer (II) can be typically recovered by adding a coagulant to an aqueous dispersion (latex) of the graft copolymer (II) produced by emulsion polymerization. As the coagulant, an acid or a water-soluble salt is used, but in the present invention, coagulation with an acid is preferred from the viewpoint of mold fouling. Specific examples of the coagulant include sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid, and the like, and 2 or more of these can be used. In addition, in the case of coagulation by an acid, the acid may adhere to the graft copolymer (II) and remain, and metal equipment in the production process may be corroded by such an acid. In order to prevent this, it is preferable to recover the graft copolymer (II) after neutralizing the acid remaining in the graft copolymer (II) with a basic compound (neutralizing agent). At this time, since the neutralizing agent adheres to the graft copolymer (II), the graft copolymer (II) tends to exhibit basicity. In the present invention, sodium hydroxide is preferred as the neutralizing agent.

Here, in the present invention, whether or not the graft copolymer (II) is basic can be judged by the following method. Initially, the graft copolymer (II) was mixed with water to prepare a slurry having a solid content concentration of 10% by weight. Next, it was left in a water bath at 90 ℃ for 3 hours, and then, the graft copolymer (II) was removed using a filter paper (5 kinds A: JIS P3801 (1995)). Further, the temperature of the filtrate was lowered to 20 ℃ and the pH of the filtrate was measured with a pH meter. Basic if the pH exceeds 7. When the pH exceeds 7, the effect of the present invention is easily obtained, and when the pH is 8 or more, a further effect is obtained.

In the thermoplastic resin composition of the present invention, when the total content of the polycarbonate resin (I), the graft copolymer (II), the vinyl copolymer (III), and the inorganic filler (IV) is 100% by weight, the content of the graft copolymer (II) is preferably in the range of 3 to 15% by weight, more preferably 4 to 12% by weight, and still more preferably 5 to 9% by weight. When the amount of the graft copolymer (II) added is 3% by weight or more, the impact resistance is not lowered, and when it is 15% by weight or less, the fluidity is not lowered, which is preferable.

[ vinyl copolymer (III) ]

The vinyl copolymer (III) constituting the thermoplastic resin composition of the present invention is preferably a vinyl copolymer obtained by copolymerizing at least an aromatic vinyl monomer (D) and a vinyl cyanide monomer (E).

In the copolymerization, the amount of the aromatic vinyl monomer (D) is preferably 60 to 85% by weight, the amount of the vinyl cyanide monomer (E) is preferably 15 to 40% by weight, more preferably 65 to 80% by weight, the amount of the vinyl cyanide monomer (E) is 20 to 35% by weight, still more preferably 70 to 80% by weight, and the amount of the vinyl cyanide monomer (E) is 20 to 30% by weight.

When the aromatic vinyl monomer (D) is 60% by weight or more, the compatibility with the polycarbonate resin (I) is improved, and the mechanical properties such as impact resistance are improved. When the amount of the aromatic vinyl monomer (D) is 85% by weight or less, the impact resistance tends to be improved by improving the compatibility with the graft copolymer (II), which is preferable.

In the present invention, the vinyl copolymer (III) does not contain the diene rubber polymer (a1) and the acrylic rubber polymer (a 2). Namely, a copolymer different from the graft copolymer (II-1) and the graft copolymer (II-2).

Examples of the aromatic vinyl monomer (D) which is a constituent of the vinyl copolymer (III) include styrene, α -methylstyrene, vinyltoluene, o-ethylstyrene, p-methylstyrene, m-methylstyrene, t-butylstyrene, vinyltoluene, chlorostyrene, and bromostyrene, similarly to the aromatic vinyl monomer (B) in the graft copolymer (II). These may be used in combination of 1 kind or more. Among them, styrene is particularly preferably used.

Examples of the vinyl cyanide monomer (E) which is a constituent of the vinyl copolymer (III) include acrylonitrile, methacrylonitrile, and ethacrylonitrile, and acrylonitrile is particularly preferably used, similarly to the vinyl cyanide monomer (C) in the graft copolymer (II). These may be used in combination of 1 kind or more.

In addition, in the vinyl copolymer (III), as in the graft copolymer (II), other vinyl monomers copolymerizable with the aromatic vinyl monomer (D) and the vinyl cyanide monomer (E) may be used to such an extent that the effect of the present invention is not lost. Specific examples of the other vinyl monomers include N-phenylmaleimide, N-methylmaleimide, and methyl methacrylate, and these monomers can be selected according to the purpose, and they can be used alone or in combination of two or more. N-phenylmaleimide is preferable if the heat resistance and flame retardancy are further improved. In addition, if importance is attached to the improvement of hardness, methyl methacrylate is preferably used.

The weight average molecular weight of the vinyl copolymer (III) constituting the thermoplastic resin composition of the present invention is 110,000 or less, preferably 105,000 or less, and more preferably 100,000 or less. The lower limit of the weight average molecular weight is not particularly limited, but is preferably 90,000 or more from the viewpoint of impact resistance.

Examples of the vinyl copolymer (III) include an acrylonitrile/styrene copolymer (AS resin), a methyl methacrylate/styrene copolymer (MS resin), and the like. Among them, acrylonitrile/styrene copolymer (AS resin) is preferable.

In the thermoplastic resin composition of the present invention, when the total content of the polycarbonate resin (I), the graft copolymer (II), the vinyl copolymer (III), and the inorganic filler (IV) is 100% by weight, the content of the vinyl copolymer (III) is preferably in the range of 4 to 12% by weight, more preferably 4 to 10% by weight, and still more preferably 4 to 8% by weight. When the amount of the vinyl copolymer (III) added is 4% by weight or more, the molded article hardly has a silver appearance, and when the amount is 12% by weight or less, the impact resistance is not lowered, which is preferable.

In the present invention, the MFR ratio ((III)/(I)) of the vinyl copolymer (III) to the polycarbonate resin (I) at 240 ℃ under 10kg is 7 to 12 inclusive. More preferably 7 to 11, and still more preferably 8 to 11. When 7 or more, the silver appearance is not deteriorated, and when 12 or less, the fluidity is not lowered, which is preferable.

Here, in the present invention, the Silver appearance refers to an appearance defect caused by Silver streaks (Silver streaks) and refers to a Silver stripe pattern. Typically, when a mold is filled with a resin composition measured in a cylinder of an injection molding machine, gas generated in the resin composition by alkali decomposition of the polycarbonate resin is stretched by shear generated at an interface between the resin composition in a molten state and the mold, and the molded product surface has a striped appearance defect.

In a resin composition in which a polycarbonate resin (I) and a graft copolymer (II) are compounded, the graft copolymer (II) may be alkaline, and if such a graft copolymer (II) comes into contact with the polycarbonate resin, the polycarbonate resin is decomposed by the alkali, and bubbles (gas) are generated by the decomposition, resulting in a poor appearance of a molded article such as silver streaks. The alkali decomposition means that an alkali such as hydroxide ion acts on a carbonate bond portion as a catalyst, hydrolysis is promoted, and a gas such as carbon dioxide or a low molecular weight component is generated.

In a resin composition in which two or more resins are blended, when the ratio of the melt viscosities of the respective resins is small, compatibility tends to occur. In other words, if the ratio of the melt viscosities of the resins is large, the resins tend to be phase-separated easily.

Therefore, in the present invention, the difference between the melt viscosities at 240 ℃ of the vinyl copolymer (III) and the polycarbonate resin (I) is set to a specific range, thereby promoting the phase separation of the vinyl copolymer (III) and the polycarbonate resin (I).

When the vinyl copolymer (III) is separated from the polycarbonate resin (I), it is considered that the vinyl copolymer (III) is biased around the graft copolymer (II) having a more similar chemical structure, and the probability frequency of the contact between the graft copolymer (II) having basicity and the polycarbonate resin (I) becomes small, whereby it is estimated that the decomposition of the polycarbonate resin is suppressed and the appearance of silver can be suppressed.

In the present invention, the method for producing the vinyl copolymer (III) is not particularly limited, and bulk polymerization, suspension polymerization, bulk suspension polymerization, solution polymerization, emulsion polymerization, precipitation polymerization, a combination thereof, and the like can be used. The method of adding the monomers is not particularly limited either, and the monomers may be added together at the initial stage, or the monomers may be polymerized in several stages in order to form or prevent the composition distribution of the copolymer.

In the present invention, the initiators used for the polymerization of the vinyl copolymer (III) are suitably the initiators mentioned for the graft copolymer (II-1).

In the polymerization, a chain transfer agent such as mercaptan or terpene may be used for the purpose of adjusting the polymerization degree of the graft copolymer (II-1) or the vinyl copolymer (III). Specific examples of the chain transfer agent include n-octyl mercaptan, t-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, terpinolene, and the like. Among them, n-octyl mercaptan, t-dodecyl mercaptan and n-dodecyl mercaptan are preferably used. When these chain transfer agents are used, 1 or 2 or more species are used in combination.

[ inorganic Filler (IV) ]

The shape of the inorganic filler (IV) constituting the thermoplastic resin composition of the present invention may be any of plate-like, fibrous, powdery, granular, and the like. Specifically, examples of the filler include powdery and granular fillers such as glass flakes, mica, talc, alumina flakes, kaolin, carbon flakes, metal flakes, flaky carbon, graphite, and clay, plate-like glass fibers, PAN-based and pitch-based carbon fibers, stainless steel fibers, metal fibers such as aluminum fibers and brass fibers, organic fibers such as aramid fibers, gypsum fibers, ceramic fibers, asbestos fibers, zirconia fibers, alumina fibers, silica fibers, titanium oxide fibers, silicon carbide fibers, glass fibers, rock wool, potassium titanate whiskers, barium titanate whiskers, aluminum borate whiskers, and silicon nitride whiskers, whisker-like fillers, silica, calcium carbonate, glass beads, glass microspheres, molybdenum disulfide, wollastonite, montmorillonite, titanium oxide, zinc oxide, barium sulfate, calcium polyphosphate, and graphite.

In particular, the type of the glass fiber is not particularly limited as long as it is a type generally used for reinforcing resins, and can be selected from, for example, long-fiber type, short-fiber type chopped strands, milled fibers, and the like. The inorganic filler may be used by treating the surface thereof with a known coupling agent (e.g., a silane coupling agent, a titanate coupling agent, etc.) or another surface treatment agent.

The glass fibers may be coated or bundled with a thermoplastic resin such as an ethylene/vinyl acetate copolymer or a thermosetting resin such as an epoxy resin.

The inorganic filler may be coated or bundled with a thermoplastic resin such as an ethylene/vinyl acetate copolymer or a thermosetting resin such as an epoxy resin, or may be treated with a coupling agent such as an aminosilane or an epoxysilane.

These fillers may be used in combination of 2 or more.

In the present invention, mica, talc, kaolin, calcium carbonate, and wollastonite are preferable. Among them, particularly talc and wollastonite are preferable in terms of dimensional stability and surface appearance.

When the inorganic filler (IV) is talc, the average particle diameter of talc is preferably 1.0 to 30.0. mu.m, more preferably 2.0 to 20.0. mu.m, and still more preferably 3.0 to 10.0. mu.m, from the viewpoint of a high balance among mechanical properties, dimensional stability, retention stability, and appearance of a molded article. When the average particle diameter is 1.0 μm or more, retention stability tends to be improved and appearance of the molded article tends to be improved, and when the average particle diameter is 30.0 μm or less, mechanical properties and dimensional stability tend to be improved, which is preferable.

When the inorganic filler (IV) is wollastonite, the fiber length is preferably 5.0 to 300.0. mu.m, more preferably 6.0 to 250.0. mu.m, and still more preferably 7.0 to 200.0. mu.m. The average fiber diameter is preferably 1.0 to 10.0. mu.m, more preferably 2.0 to 9.0. mu.m, and still more preferably 3.0 to 8.0. mu.m.

The aspect ratio is preferably 3 to 30, more preferably 3 to 20, and still more preferably 3 to 15. The aspect ratio is preferably 3 or more, because the reinforcing effect is sufficient, and further, in the case of 30 or less, the roughness of the appearance of the molded article is suppressed.

In the thermoplastic resin composition of the present invention, when the total content of the polycarbonate resin (I), the graft copolymer (II), the vinyl copolymer (III), and the inorganic filler (IV) is 100% by weight, the content of the inorganic filler (IV) is preferably in the range of 10 to 20% by weight, more preferably 11 to 19% by weight, and still more preferably 12 to 18% by weight. If the amount of the inorganic filler (IV) added is 10% by weight or more, the mechanical properties and dimensional stability are not deteriorated, and if the amount is 20% by weight or less, the retention stability is not deteriorated, and the silver appearance of the molded article is not deteriorated, which is preferable.

[ phosphate ester-based Compound (V) ]

As the phosphate ester compound (V) constituting the thermoplastic resin composition of the present invention, for example, a compound represented by the following general formula (2) can be used.

In the general formula (2) R₁、R₂、R₃And R₄Each independently of the other represents a hydrogen atom or a 1-valent organic group, provided that R₁、R₂、R₃And R₄At least one of which is a 1-valent organic group. X is a 2-valent organic group, k, l, m and N are each independently 0 or 1, and N is an integer of 0 to 10.

In the general formula (2), examples of the 1-valent organic group include an alkyl group, an aryl group, and a cycloalkyl group which may be substituted, and examples of the substituent in the case of substitution include an alkyl group, an alkoxy group, an alkylthio group, an aryl group, an aryloxy group, and an arylthio group, and a group obtained by combining these substituents (e.g., an arylalkoxyalkyl group) or a group obtained by combining these substituents through oxygen, sulfur, a nitrogen atom, or the like (e.g., an arylsulfonyrylyl group) may be a substituent. In particular, the 1-valent organic group is preferably a 2, 6-dimethylphenyl group.

Examples of the 2-valent organic group include alkylene groups, optionally substituted phenylene groups, and groups derived from polyphenols and polynuclear phenols (e.g., bisphenols). In particular, resorcinol is preferable as the 2-valent organic group.

Suitable specific examples of the phosphate ester-based compound (V) include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, tricyclohexyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, hydroxyphenyl diphenyl phosphate, tolyldiphenyl phosphate, xylyldiphenyl phosphate, and compounds represented by the following chemical formula (3), chemical formula (4) or chemical formula (5).

In the thermoplastic resin composition of the present invention, the content of the phosphate ester compound (V) is in the range of 1 to 10 parts by weight based on 100 parts by weight of the total of (I) to (IV). When the amount is 1 part by weight or more, the silver appearance tends to be improved, and when the amount is 10 parts by weight or less, the heat resistance and impact resistance tend to be improved. The content of the phosphate compound (V) is preferably 2 parts by weight or more, and more preferably 3 parts by weight or more. Further, it is preferably 8 parts by weight or less, and more preferably 6 parts by weight or less.

In addition, a known impact resistance improving material may be used within a range not to impair the characteristics of the present invention. However, it is preferable not to use a polyester resin such as polybutylene terephthalate or polyethylene terephthalate, or a crystalline resin such as nylon resin, from the viewpoint of lowering heat resistance.

In addition, a known matting modifier can be used within a range not to impair the characteristics of the present invention.

Further, a hindered phenol-based antioxidant, a sulfur-containing compound-based antioxidant, a phosphorus-containing organic compound-based antioxidant, a thermal antioxidant such as a phenol-based antioxidant and an acrylate-based antioxidant, a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, a salicylate-based ultraviolet absorber, a polymer or copolymer made of acrylic acid and an ester thereof, methacrylic acid and an ester thereof other than the graft copolymer (II-2), a molding processing aid such as modified polytetrafluoroethylene, a flame retardant/flame retardant aid, an antibacterial agent represented by a silver-based antibacterial agent, an antifungal agent, carbon black, titanium oxide, a mold release agent, a lubricant, a pigment, a dye, and the like may be added as needed within a range not to impair the characteristics of the present invention.

The thermoplastic resin composition of the present invention can be obtained by melt-mixing the respective resin components constituting the composition. The melt-mixing method is not particularly limited, and a method of melt-mixing a material using a single-screw or twin-screw with a cylinder having a heating device and a vent may be employed. The heating temperature during melt mixing is usually selected from the range of 230 to 320 ℃, but the temperature gradient during melt mixing and the like can be freely set within a range not impairing the object of the present invention. In the case of using a twin-screw, the screws may be rotated in the same direction or in different directions. The screw may be either an engaging type or a non-engaging type.

The method for molding the thermoplastic resin composition of the present invention is not particularly limited, and the thermoplastic resin composition is suitably molded by injection molding. The injection molding may be performed at a temperature range of a generally molded thermoplastic resin group, preferably 240 to 300 ℃. The temperature of the mold during injection molding is preferably in the range of 30 to 80 ℃ which is generally used for molding.

The thermoplastic resin composition of the present invention suppresses the silver appearance of a molded article and has excellent fluidity. Further, the thermoplastic resin composition comprising the graft copolymer (II-2) is excellent in weather resistance in addition to the above. Therefore, the thermoplastic resin composition of the present invention is suitable for use in large-sized or complex-shaped molded articles.

That is, the resin composition of the present invention can be suitably used not only for a window panel, a center console, a center instrument group, a console box (console shade), a joystick controller, and the like for automobile interior, but also for a rear spoiler, a grill, a garnish, a door mirror, a roof, a fender, a bumper, and the like, which are exterior materials for automobiles. Furthermore, the resin composition can be suitably used for electric and electronic purposes, OA equipment purposes, and house and building material purposes.

Examples

The present invention will be described in more detail with reference to the following examples, which are not intended to limit the scope of the present invention and may be variously modified. First, the evaluation methods in the reference examples, and comparative examples are described below.

(1) Graft ratio

Prescribed amounts (m; about 1G) of the graft copolymers (II-1), (II-2) obtained by adding 200ml of acetone thereto, refluxing in a hot water bath at a temperature of 70 ℃ for 3 hours, centrifuging the solution at 8800r.p.m. (10000G) for 40 minutes, and filtering the insoluble matter. The acetone-insoluble substance thus obtained was dried under reduced pressure at 60 ℃ for 5 hours, and the mass (n; unit g) thereof was measured. The graft ratio was calculated from the following formula. Here, L is the rubber content (a real number exceeding 0 and less than 1) of the graft copolymer.

The graft ratio (% by mass) is { [ (n) - { (m) × L } ]/[ (m) × L ] } × 100.

(2) Weight average molecular weight

About 0.03g of the vinyl copolymers (III-1) to (III-5) obtained in the following were weighed and dissolved in about 15g of tetrahydrofuran to obtain a solution of about 0.2 mass%. The weight average molecular weight was determined from a GPC chromatogram using the solution in terms of polystyrene as a standard substance. The GPC measurement was measured under the following conditions.

Equipment: waters2695

Column temperature: 40 deg.C

The detector: RI2414 (differential refractometer)

Flow rate of carrier eluent: 0.3 ml/min (solvent: tetrahydrofuran)

Column: TSKgel SuperHZM-M (6.0 mmI.D.. times.15 cm), TSKgel SuperHZM-N (6.0 mmI.D.. times.15 cm) were connected in series (both manufactured by imperial ソー (strain).

Standard sample: chinese imperial ソー made monodisperse polystyrene.

(3) Silver appearance evaluation

A square plate P having an edge angle of 45 DEG in the longitudinal direction and having a width of 70mm, a length of 150mm and a thickness of 3mm, which is schematically shown in FIG. 1(a) and FIG. 1(b), was molded by using an injection molding machine with a cylinder temperature set to 290 ℃ and a mold temperature set to 10 ℃ (FIG. 1(a) is a plan view of the square plate P, FIG. 1(b) is a sectional view taken from A-A of the square plate P, and the position of a gate of the injection molding is indicated by a white bottom arrow). The less the occurrence of silver streaks in the obtained molded article, the more excellent the silver appearance, and the judgment was made by visual observation based on the following criteria. The acceptable levels were set at 3 to 5, and the unacceptable levels were set at 1 and 2.

5: no silver streaks are generated.

4: the number of generated silver streaks was less than 10, which was not problematic.

3: the number of the generated silver streaks was 10 or more and less than 30, which was not problematic.

2: the occurrence of silver streaks in the vicinity of the gate was noticeable and the appearance was problematic.

1: the formation of silver streaks in the entire molded article resulted in a problem in appearance.

(4) Fluidity, melt flow rate

The polycarbonate-based resin (I), the vinyl-based copolymer (III) obtained as follows, and the pellets obtained in each of the examples and comparative examples were subjected to the following conditions in accordance with ISO1133(2011 edition) at temperatures: 240 ℃ and load: the melt flow rate was measured under 10kg conditions.

(5) Impact resistance

From the pellets obtained in each of examples and comparative examples, a multi-mesh test piece a1 type defined in JIS K7139 (2009) was molded using an injection molding machine in which the cylinder temperature was set to 250 ℃ and the mold temperature was set to 60 ℃, and Charpy impact strength (Charpy impact strength) was measured according to ISO179/1eA (2009) using a B2 type test piece cut out therefrom.

(6) Heat resistance

Heat distortion temperature: measured according to ISO75-2 (measured under 1.8 MPa). The test piece was obtained by molding a multi-purpose test piece a1 type specified in JIS K7139 (2009) using an injection molding machine in which the cylinder temperature was set to 250 ℃ and the mold temperature was set to 60 ℃.

< polycarbonate-based resin (I) >

A polycarbonate-series resin (I-1); trade name "" ユーピロン "(registered trademark) H-4000", viscosity average molecular weight: 15,000, manufactured by Mitsubishi エンジニアリングプラスチック (LTD.)

A polycarbonate-series resin (I-2); trade name "" ユーピロン "(registered trademark) H-3000", viscosity average molecular weight: 18,000 manufactured by Mitsubishi エンジニアリングプラスチック

A polycarbonate-series resin (I-3); trade name "ユーピロン" (registered trademark) S-3000 ", viscosity average molecular weight: 21,500 manufactured by Mitsubishi エンジニアリングプラスチック (LTD.)

< preparation of graft copolymer (II-1) >

A rubber-reinforced styrene/acrylonitrile copolymer latex was obtained by emulsion-polymerizing a monomer mixture comprising 40% by weight of styrene and 15% by weight of acrylonitrile in the presence of 45% by weight (in terms of solid content) of a polybutadiene latex (2 kinds of rubber having a weight average particle diameter of 350nm and 800nm in combination, in a mass ratio of 8: 2, diene rubber polymer (A1)). This was added to a dilute sulfuric acid aqueous solution to coagulate it, and then neutralized with a sodium hydroxide aqueous solution, followed by washing, dehydration and drying steps to prepare a graft copolymer (II-1). The graft ratio was 25%. The graft copolymer (II-1) was basic (pH 8).

< preparation of graft copolymer (II-2) >

[ Process for obtaining acrylic rubber Polymer (A2) ]

130 parts by weight of pure water and 1 part by weight (in terms of solid content) of an aqueous solution of potassium disproportionate abietate as an emulsifier were charged into a reaction vessel, the temperature was raised to 75 ℃ and a mixture (mixture 1) of 19.8 parts by weight of n-butyl acrylate and 0.2 part by weight of allyl methacrylate was continuously added for 1 hour with stirring (addition step 1). Subsequently, 8 parts by weight of a2 wt% potassium persulfate aqueous solution and 1.5 parts by weight (in terms of solid content) of a disproportionated potassium rosinate aqueous solution were continuously added over 6 hours (addition step 2). Further, a mixture (mixture 3) of 79.2 parts by weight of n-butyl acrylate and 0.8 part by weight of allyl methacrylate was added over 4 hours after 2 hours from the start of the addition of the aqueous potassium persulfate solution and the aqueous potassium disproportionated rosin solution (addition step 3). After the completion of the addition, the mixture was further kept for 1 hour to obtain an acrylic rubber polymer (a2) latex by emulsion polymerization.

[ procedure for obtaining graft copolymer ]

Subsequently, 13.2 parts by weight of pure water, 0.48 part by weight of anhydrous glucose, a mixture of 0.26 part by weight of sodium pyrophosphate and 0.01 part by weight of ferrous sulfate, a mixture of 0.4 part by weight of potassium oleate and 12.5 parts by weight of pure water, 50 parts by weight (in terms of solid content) of acrylic rubber polymer (A2) latex and 94.3 parts by weight of pure water were charged into a reaction vessel, heated to 58 ℃ and, under stirring, a mixture (i) of 36.5 parts by weight of styrene, 13.5 parts by weight of acrylonitrile and 0.2 part by weight of t-dodecyl mercaptan was continuously added over 4 hours. After 0.5 hour from the start of the continuous addition, the temperature in the vessel was raised to 62 ℃ while a mixture of 0.3 parts by weight of cumene hydroperoxide, 2.0 parts by weight of potassium oleate and 12.5 parts by weight of pure water was continuously added over 5 hours. Subsequently, at the end of the addition of the mixture (i), the temperature was further raised up to 65 ℃ to obtain a graft copolymer latex having a polymerization rate of 98%. This was added to a dilute sulfuric acid aqueous solution to coagulate it, and then neutralized with a sodium hydroxide aqueous solution, followed by washing, dehydration and drying steps to obtain a powdery graft copolymer (II-2). The graft ratio was 30%. The graft copolymer (II-2) was basic (pH 8).

< preparation of vinyl copolymer (III) >

A monomer mixture comprising 76% by weight of styrene and 24% by weight of acrylonitrile was suspension-polymerized to obtain a slurry, and the slurry was subjected to washing, dehydration and drying steps to prepare a vinyl copolymer (III-1) having a weight-average molecular weight of 90,000.

A monomer mixture comprising 76% by weight of styrene and 24% by weight of acrylonitrile was suspension-polymerized to obtain a slurry, and the slurry was subjected to washing, dehydration and drying steps to prepare a vinyl copolymer (III-2) having a weight-average molecular weight of 95,000.

A monomer mixture comprising 76% by weight of styrene and 24% by weight of acrylonitrile was suspension-polymerized to obtain a slurry, and the slurry was subjected to washing, dehydration and drying steps to prepare a vinyl copolymer (III-3) having a weight-average molecular weight of 99,000.

A monomer mixture comprising 76% by weight of styrene and 24% by weight of acrylonitrile was suspension-polymerized to obtain a slurry, and the slurry was subjected to washing, dehydration and drying steps to prepare a vinyl copolymer (III-4) having a weight-average molecular weight of 108,000.

A monomer mixture comprising 76% by weight of styrene and 24% by weight of acrylonitrile was suspension-polymerized to obtain a slurry, and the slurry was subjected to washing, dehydration and drying steps to prepare a vinyl copolymer (III-5) having a weight-average molecular weight of 115,000.

< inorganic Filler (IV) >)

Talc (IV-1); trade name "ミクロンホワイト # 5000S", average particle size 4.8 μm, manufactured by Lin chemical Co., Ltd.

Wollastonite (IV-2); the trade name "NYGLOS 4W 10992" was イメリススペシャリティーズジャパン (manufactured by KAPPON NAKAPPA), having an average fiber diameter of 7 μm and an average fiber length of 63 μm.

< phosphate ester-based Compound (V) >

Aromatic condensed phosphoric acid ester; trade name "PX-200" manufactured by Dai eight chemical Co., Ltd.

Examples 1 to 14 and comparative examples 1 to 6

The polycarbonate resin (I), the graft copolymer (II), the vinyl copolymer (III), the inorganic filler (IV), and the phosphate compound (V) were blended as shown in the table, and melt-kneaded by a co-rotating twin-screw extruder (temperature range: 240 to 260 ℃) having a screw diameter of 30mm to obtain pellets. The obtained particles were subjected to the above evaluation. From the obtained pellets, test pieces were produced using an injection molding machine (molding temperature 250 ℃ C., mold temperature 60 ℃ C.), and evaluated by the above-mentioned method. However, the molded article for surface appearance confirmation of the above (3) was produced under the conditions described in (3). The evaluation results are shown in the table.

The thermoplastic resin compositions of examples 1 to 14 suppressed the silver appearance of the molded articles and were excellent in fluidity. On the other hand, as is clear from comparison of examples 1 to 4 with comparative examples 1 to 3, if the ratio of the melt flow rates of the vinyl copolymer (III) and the polycarbonate resin (I) is smaller than the range specified in the present invention, the appearance is deteriorated, and if it is larger, the fluidity is deteriorated. Further, as is clear from comparison of examples 5, 6 and 7 with comparative example 4, if the molecular weight of the vinyl copolymer (III) exceeds the range specified in the present invention, the fluidity is deteriorated. As is clear from comparison of examples 8 to 10 with comparative examples 5 and 6, if the amount of the phosphate ester compound (V) added is smaller than the range specified in the present invention, the appearance is deteriorated, and if it is larger, the impact strength is lowered.

[ Table 1]

[ Table 2]

[ Table 3]

The present invention has been described in detail and with reference to specific embodiments thereof, but it will be apparent to one skilled in the art that various changes and modifications can be added without departing from the spirit and scope thereof. The present application is based on japanese patent application published on 26/3/2019 (japanese patent application 2019-58158), the contents of which are incorporated herein by reference.

Industrial applicability

The present invention relates to a thermoplastic resin composition having excellent flowability and suppressed silver appearance of molded articles, and is used in the automotive field for automotive exterior parts such as rear spoilers, wheel caps, door mirrors, and radiator grilles, automotive interior parts such as power window panels, center consoles, center cluster consoles, joystick controllers, and console boxes, and automotive exterior parts such as rear spoilers, grilles, garnishes, door mirrors, roofs, fenders, and bumpers. In addition to the automotive field, the present invention can be suitably used in the fields of OA equipment, home electric appliances, building materials for houses, suitcases, bags, and the like.

Description of the symbols

P square plates.