JP2007023093A - Thermoplastic resin composition and molded article thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition having excellent moldability and giving a molded article having excellent scratch resistance, impact resistance and coloring property and provide a molded article having excellent scratch resistance, impact resistance and coloring property (color-developing property). <P>SOLUTION: The thermoplastic resin composition contains (A) 1-99 pts.mass of a graft copolymer produced by grafting at least one kind of monomer selected from aromatic vinyl monomers, (meth)acrylic acid esters and vinyl cyanide monomers to an olefin rubber polymer G and (B) 1-99 pts.mass of a vinyl polymer provided that the grafting ratio of the graft copolymer is 65-90 mass% and the reduced viscosity (ηsp/C) of the acetone-soluble fraction of the graft copolymer A is 0.35-0.60 dl/g. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

Improving the impact resistance of a molded product makes it possible to cope with the reduction in thickness and size of the molded product, and thus has great industrial utility, and various studies have been made so far.
In particular, a resin material in which a rubber component having a low glass transition temperature (Tg) and a low elastic modulus is dispersed in a resin matrix has been industrialized because the molded product exhibits excellent impact resistance.

  Further, an AES resin (acrylonitrile-ethylene / propylene rubber-) obtained by grafting styrene, acrylonitrile or the like onto the rubber component using an ethylene-α-olefin copolymer having substantially no double bond in the main chain. It is known that styrene copolymers) have a higher resistance to ultraviolet rays, oxygen and ozone, and are extremely excellent in weather resistance than ABS resins (acrylonitrile-butadiene-styrene copolymers) using conjugated diene rubbers. These AES resins and the like are widely used for vehicle exterior parts and the like.

  For molded articles used for vehicle exterior parts, not only impact strength, but also design properties, in particular pigment or dye coloring properties (color developing properties) are desired in order to increase the value of the product. However, AES resin has a problem that coloring property is insufficient. Thus, as an AES resin with improved colorability, a resin composition in which a copolymer containing a methacrylic ester unit as a main component is blended with an AES resin has been proposed (see, for example, Patent Documents 1 to 4). .

However, although the above resin composition has good weather resistance and colorability (color development) of the obtained molded article, the molded article has scratch resistance, impact resistance, and resin composition moldability (fluidity). ) Is inadequate, and cannot be said to be sufficient to meet recent severe needs. That is, hitherto, in a resin composition containing a graft copolymer containing a rubber component made of an ethylene-α-olefin copolymer and a thermoplastic resin, the resulting molded article has scratch resistance and impact resistance. However, no one that satisfies all of the colorability and moldability of the resin composition has been found, and development of a resin composition that satisfies these requirements has been strongly desired.
JP 57-117557 A JP 61-34045 A Japanese Patent Laid-Open No. 61-141747 JP 61-141748 A

  The object of the present invention is to obtain a molded article excellent in scratch resistance, impact resistance (especially low-temperature surface impact) and colorability (color development), and a thermoplastic resin excellent in moldability (fluidity). An object of the present invention is to provide a composition and a molded article excellent in scratch resistance, impact resistance (especially low temperature surface impact), and colorability (color development).

  The present inventors have investigated the graft structure of a graft copolymer (graft ratio, reduced viscosity of acetone-soluble matter) for a thermoplastic resin composition comprising a graft copolymer containing an olefinic rubber-like polymer and a thermoplastic resin. ) And the moldability of the thermoplastic resin composition containing it, the impact resistance of the molded product, and the colorability, and as a result, the graft structure (graft ratio, reduced viscosity of acetone-soluble matter) should be specified. Thus, the inventors have found that all the above problems can be solved, and have reached the present invention.

  That is, the thermoplastic resin composition of the present invention is selected from the group consisting of an olefin rubber-like polymer (G), an aromatic vinyl monomer, a (meth) acrylic acid ester, and a vinyl cyanide monomer. 1 to 99 parts by mass of graft copolymer (A) grafted with at least one selected monomer and 1 to 99 parts by mass of vinyl polymer (B) (however, graft copolymer) The total of (A) and the vinyl polymer (B) is 100 parts by mass.), The graft copolymer (A) has a graft ratio of 65 to 90% by mass, and the graft copolymer ( The reduced viscosity (ηsp / C) of the acetone-soluble component of A) is 0.35 to 0.60 dl / g.

The graft copolymer (A) is obtained by adding 80 to 60 parts by mass of an aromatic vinyl monomer and 20 to 40 parts by mass of a vinyl cyanide monomer (provided aromatic The total of the vinyl group vinyl monomer and the vinyl cyanide monomer is 100 parts by mass.
The gel content of the olefin rubber-like polymer (G) is preferably 30 to 90% by mass.
The olefin rubber-like polymer (G) is preferably produced by a mechanical emulsification method.

The olefinic rubbery polymer (G) is composed of 80 to 99.9 parts by mass of an ethylene-propylene rubbery polymer (E), 0.1 to 20 parts by mass of a low molecular weight acid-modified α-olefinic polymer, (However, the total of the ethylene-propylene rubber-like polymer (E) and the low molecular weight acid-modified α-olefin polymer is 100 parts by mass).
The molded article of the present invention is formed by molding the thermoplastic resin composition of the present invention.

According to the thermoplastic resin composition of the present invention, it is possible to obtain a molded article excellent in scratch resistance, impact resistance (particularly, low-temperature surface impact), and colorability (color development). Moreover, the thermoplastic resin composition of the present invention is excellent in moldability (fluidity).
The molded article of the present invention is excellent in scratch resistance, impact resistance (particularly low temperature impact), and colorability.

<< Olefin rubbery polymer (G) >>
The structure of the olefin rubber polymer (G) used in the graft copolymer (A) according to the present invention is not particularly limited, but an ethylene-propylene rubber polymer (E) is preferably exemplified. .

  Examples of the ethylene-propylene rubber-like polymer (E) include an ethylene-propylene copolymer (EPR) and an ethylene-propylene-nonconjugated diene copolymer (EPDM). Of these, ethylene-propylene-nonconjugated diene copolymer (EPDM) is preferred because the resulting molded article has excellent impact strength.

  Specific examples of the ethylene-propylene-nonconjugated diene copolymer include, as nonconjugated diene units, for example, dicyclopentadiene, ethylidene norbornene, 1,4-hexadiene, 1,5-hexadiene, 2-methyl-1,5. -A copolymer having one or more of hexadiene, 1,4-cycloheptadiene, 1,5-cyclooctadiene and the like. Among these, an ethylene-propylene-nonconjugated diene copolymer having a dicyclopentadiene unit and / or an ethylidene norbornene unit as a nonconjugated diene unit is preferable because of excellent impact strength and molded appearance of the obtained molded product.

The molar ratio of ethylene units to propylene units (ethylene units: propylene units) in the ethylene-propylene rubber-like polymer (E) is preferably in the range of 5: 1 to 3: 2. Within this range, the resulting molded article is excellent in impact resistance.
The proportion of unsaturated groups in the ethylene-propylene rubber-like polymer (E) depends on the kind and ratio of the above-mentioned nonconjugated diene units, but may be in the range of 8-50 in terms of iodine value. preferable. Within this range, the resulting molded article is excellent in impact resistance and weather resistance.

  The production method of the olefin rubber-like polymer (G) is not particularly limited, and a known method can be used. In particular, an uncrosslinked ethylene-propylene rubber-like polymer (E) is obtained by the “mechanical emulsification method”. After the water emulsion was obtained, a cross-linked ethylene-propylene rubber-like polymer (E) (olefin rubber-like polymer was obtained by adding a crosslinking agent and a polymerization initiator to the water emulsion and subjecting to heat treatment. The method of obtaining the latex (G)) is preferred. The “mechanical emulsification method” is a method in which mechanical shearing force is applied to an uncrosslinked ethylene-propylene rubber-like polymer (E) produced in a separate process in the presence of an emulsifier and a wax-like polymer. This is a method for finely dispersing and stabilizing the non-crosslinked ethylene-propylene rubber polymer (E) in water. When the olefinic rubbery polymer (G) produced by this method is used, the manipulation of the gel content of the olefinic rubbery polymer (G) becomes easy, and the resulting molded article has scratch resistance. Excellent.

The mass average particle diameter of the olefin-based rubbery polymer (G) in the latex is in an appropriate range for obtaining a molded product excellent in good colorability, glossiness, and impact resistance aimed by the present invention. It is desirable to be controlled. The mass average particle diameter is preferably 200 to 800 nm, more preferably 250 to 700 nm, and still more preferably 300 to 600 nm, from the viewpoint of impact resistance of the obtained molded product.
Methods for controlling the mass average particle diameter of the olefin rubber-like polymer (G) in the latex include the type or amount of emulsifier, the type or amount of wax-like polymer, the shear force during mechanical emulsification, temperature conditions, etc. The method of adjusting is mentioned.

  The emulsifier that can be used in the mechanical emulsification may be any commonly used emulsifier, and examples thereof include known ones such as a long-chain alkyl carboxylate, a sulfosuccinic acid alkyl ester salt, and an alkylbenzene sulfonate. Further, the amount used thereof suppresses the thermal coloring of the resulting thermoplastic resin composition, and the particle diameter can be easily controlled during mechanical emulsification. Therefore, the non-crosslinked ethylene-propylene rubber polymer 100 used as a raw material is used. 1-8 mass parts is preferable with respect to mass parts.

The waxy polymer that can be used in the mechanical emulsification is preferably a thermoplastic polymer containing a carboxylic acid or an anhydride group thereof, which can be neutralized. Among these, a low molecular weight acid-modified α-olefin polymer obtained by graft polymerization of an ethylenically unsaturated carboxylic acid or an anhydride thereof to a low molecular weight α-olefin polymer is particularly preferable.
The low molecular weight acid-modified α-olefin polymer preferably has a mass average molecular weight of 1,000 to 9,000, more preferably 1,500 to 7,500, and 2,000 to 6,000. Is more preferable. Furthermore, what has an acid value in the range of 20-40 mgKOH / g is preferable. When it is in this range, the molded article obtained has excellent molding appearance (surface gloss, colorability) and scratch resistance.

  The ratio of the ethylene-propylene rubber-like polymer (E) and the low molecular weight acid-modified α-olefin polymer is 80-99.9 parts by mass of the ethylene-propylene rubber-like polymer (E), low molecular weight acid-modified. 0.1 to 20 parts by mass of an α-olefin polymer is preferable, 85 to 99 parts by mass of an ethylene-propylene rubbery polymer (E), 1 to 15 parts by mass of a low molecular weight acid-modified α-olefin polymer (however, The total of the ethylene-propylene rubber-like polymer (E) and the low molecular weight acid-modified α-olefin polymer is 100 parts by mass). When it is in this range, the molded article obtained has excellent molding appearance (surface gloss, colorability) and scratch resistance.

As the olefin rubber polymer (G), it is optional to use a cross-linked uncrosslinked ethylene-propylene rubber polymer (E).
As the crosslinking agent, for example, polyfunctional such as divinylbenzene, allyl methacrylate, ethylene glycol dimethacrylate, 1,3-butylene dimethacrylate, tetraethylene glycol diacrylate, triallyl cyanurate, triallyl isocyanurate, pentaerythritol tetraacrylate, etc. Ionic monomers. These may be used individually by 1 type and may be used in combination of 2 or more type. Of these, divinylbenzene is preferred. The standard of the usage-amount of divinylbenzene is the range of 0.2-10 mass parts normally with respect to 100 mass parts of non-crosslinked ethylene-propylene type rubber-like polymers (E).

The gel content in the olefin rubber-like polymer (G) (100% by mass) is preferably 30 to 90% by mass, more preferably 40 to 80% by mass, further preferably 50 to 75% by mass, 55-70 mass% is especially preferable. Within this range, the resulting molded article is excellent in scratch resistance, impact resistance, and molding appearance (surface gloss, color developability).
The gel content in the olefinic rubbery polymer (G) is determined by coagulating the latex of the olefinic rubbery polymer (G) after crosslinking the ethylene-propylene rubbery polymer (E) with dilute sulfuric acid. The coagulated product was washed with water and dried, then 1 g of this was sampled and immersed in 200 ml of toluene at 120 ° C. for 5 hours, then filtered through a 200 mesh stainless steel wire mesh, the residue was dried and its mass was measured. Ask.

<< Graft Copolymer (A) >>
The graft copolymer (A) is selected from the group consisting of the above-mentioned olefin rubber-like polymer (G), aromatic vinyl monomers, (meth) acrylic acid esters, and vinyl cyanide monomers. A graft copolymer in which at least one monomer is grafted.

  As the graft copolymer (A), the olefin rubber-like polymer (G) is aromatic in terms of scratch resistance, impact resistance (particularly low-temperature surface impact), colorability and moldability (fluidity). 80-60 parts by weight of vinyl monomer and 20-40 parts by weight of vinyl cyanide monomer (however, the total of the aromatic vinyl monomer and vinyl cyanide monomer is 100 parts by weight) .) Is particularly preferred.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene and the like. One aromatic vinyl monomer may be used alone, or two or more aromatic vinyl monomers may be used in combination.
As (meth) acrylic acid esters, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, dodecyl acrylate, octadecyl acrylate, phenyl acrylate, benzyl acrylate, etc. Acrylic acid esters of methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, phenyl methacrylate, benzyl methacrylate Methacrylic acid esters such as acrylate and the like. One (meth) acrylic acid ester may be used alone, or two or more may be used in combination.
Examples of the vinyl cyanide monomer include acrylonitrile and methacrylonitrile. A vinyl cyanide monomer may be used individually by 1 type, and may use 2 or more types together.

  Since the ratio of the olefinic rubbery polymer (G) and the monomer is excellent in impact resistance and colorability of the resulting molded product, 20 to 80 parts by mass of the olefinic rubbery polymer (G), 20 to 80 parts by mass of the monomer is preferable, 30 to 75 parts by mass of the olefinic rubbery polymer (G), 25 to 70 parts by mass of the monomer are more preferable, and 40 to 70 parts by mass of the olefinic rubbery polymer (G) Parts, and 30 to 60 parts by mass of the monomer (however, the total of the olefin rubber-like polymer (G) and the monomer is 100 parts by mass).

In the present invention, a graft copolymer is used for the purpose of obtaining a molded article having a good balance of scratch resistance, impact resistance (particularly low-temperature surface impact), molding appearance and colorability, and a thermoplastic resin composition having excellent moldability. It is important to control the graft ratio of (A).
The graft ratio of the graft copolymer (A) is 65 to 90% by mass, preferably 70 to 90% by mass, and more preferably 70 to 85% by mass. By setting the graft ratio to 65% by mass or more, the color developability and impact strength of the molded product are improved, and by setting the graft rate to 90% by mass or less, the moldability (fluidity) of the thermoplastic resin composition is improved. To do.

  As a method for controlling the graft ratio of the graft copolymer (A), a method for optimizing the graft polymerization temperature or the method for supplying the monomer mixture; a method for adjusting the type or amount of the chain transfer agent or the polymerization initiator, etc. And a known method. These methods are preferably used in combination.

The graft ratio is measured as follows.
First, 20 ml of latex of the graft copolymer (A) is coagulated with 80 ml of isopropyl alcohol, and the solidified product is dried to obtain the solid content of the graft copolymer (A). And the graft copolymer yield (X) from the value is calculated | required.
X (%) = solid content of graft copolymer (A) / solid content of graft copolymer (A) when polymerized 100% × 100

Next, 2.5 g of the solid content of the graft copolymer (A) was added to 80 ml of acetone and refluxed at 65 to 70 ° C. for 3 hours. The obtained suspension acetone solution was centrifuged at 14000 rpm for 30 minutes. Then, the precipitation component and the supernatant solution (acetone solution) are separated respectively. And the precipitation component is fully dried and the mass (Y (g)) is measured. Then, the graft ratio is calculated from the following formula.
Graft rate (%) = [(Y × 100) − (olefinic rubbery polymer (G) (g) × X) used for graft polymerization] / [monomer used for graft polymerization (g) × X ]

In the present invention, a graft copolymer is used for the purpose of obtaining a molded article having a good balance of scratch resistance, impact resistance (particularly low-temperature surface impact), molding appearance and colorability, and a thermoplastic resin composition having excellent moldability. It is important to control the molecular weight of the acetone soluble part of (A). In the present invention, the reduced viscosity ηsp / C is used as an index of the molecular weight of the acetone-soluble component.
The graft copolymer (A) has a reduced viscosity ηsp / C of 0.35 dl / g to 0.60 dl / g, preferably 0.3 dl / g to 0.5 dl / g, preferably 0.3 dl / g to 0 More preferably, 4 dl / g. When the reduced viscosity ηsp / C is 0.35 dl / g or more, the impact strength of the molded product is improved, and when the reduced viscosity ηsp / C is 0.60 dl / g or less, molding of the thermoplastic resin composition is achieved. Property (fluidity) is improved.

As a method for controlling the reduced viscosity of the acetone-soluble portion of the graft copolymer (A), a method for optimizing the graft polymerization temperature or the method for supplying the monomer mixture; the type or amount of the chain transfer agent or the polymerization initiator Known methods such as a method of adjusting These methods are preferably used in combination.
The reduced viscosity ηsp / C is a value measured at 25 ° C. by dissolving 0.2 g of acetone-soluble matter in 100 ml of N, N-dimethylformamide.

  The graft copolymer (A) is produced, for example, by emulsion graft polymerization. That is, the monomer or monomer mixture used for graft polymerization is added to the latex of the olefin rubber-like polymer (G) produced by the “mechanical emulsification method” as described above, and in the presence of an emulsifier and a polymerization initiator. And can be produced by a known radical polymerization technique. At this time, various known chain transfer agents for controlling the graft ratio and the molecular weight of the graft component may be added.

  Examples of the polymerization initiator include peroxides, azo initiators, redox initiators in which an oxidizing agent and a reducing agent are combined. Of these, redox initiators are preferred, redox initiators containing organic peroxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, t-butyl peroxide as peroxides are more preferred, cumene hydroper Redox initiators comprising oxide-ferrous sulfate-sodium pyrophosphate-dextrose are particularly preferred.

  As the emulsifier, the emulsifier used in the production of the olefin rubber-like polymer (G) may be used as it is (that is, it is not necessary to add an emulsifier before graft polymerization). An emulsifier may be added. Examples of the emulsifier to be added include the same as the emulsifier used in the production of the olefin rubber-like polymer (G).

  As a method of recovering the graft copolymer (A) from the latex of the graft copolymer (A), the latex is poured into hot water in which a coagulant is dissolved, and the graft copolymer (A) is coagulated. A method of recovering the graft copolymer (A) by spraying the graft copolymer (A) latex in a heated atmosphere (spray drying) Method).

  Examples of the coagulant used in the wet method include inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, and nitric acid; metal salts such as calcium chloride, calcium acetate, and aluminum sulfate. The coagulant is selected in combination with the emulsifier used in the polymerization. That is, when only carboxylic acid soaps such as fatty acid soaps and rosin acid soaps are used as emulsifiers, the graft copolymer (A) can be recovered using any coagulant. For example, when an emulsifier that shows a stable emulsifying power even in an acidic region such as sodium alkylbenzene sulfonate is contained, an inorganic acid is insufficient, and a metal salt must be used.

  In order to obtain a dry graft copolymer (A) from the slurry of the graft copolymer (A) obtained by the wet method, first, the emulsifier residue remaining in the slurry is eluted in water by washing, Examples include a method of dehydrating this slurry with a centrifugal dehydrator or a press dehydrator, and then drying with an air dryer or the like; a method of simultaneously performing dehydration and drying with a press dehydrator, an extruder, or the like. Under the present circumstances, you may send what was discharged | emitted from the press dehydrator or the extruder directly to the extruder or molding machine which manufactures a thermoplastic resin composition, and may be made into a molded article.

<< Vinyl polymer (B) >>
The vinyl polymer (B) is obtained by (co) polymerizing vinyl monomers.
Examples of vinyl monomers include aromatic vinyl monomers, vinyl cyanide monomers, (meth) acrylic acid esters, maleimide compounds, and unsaturated carboxylic acids.

  Examples of the vinyl polymer (B) include acrylonitrile-styrene copolymer (SAN), polymethyl methacrylate (PMMA), styrene-methyl methacrylate copolymer (MS), and acrylonitrile-α-methylstyrene copolymer (αSAN). , Acrylonitrile-methyl methacrylate copolymer (MAN), acrylonitrile-styrene-methyl methacrylate terpolymer (MAS), styrene-acrylonitrile-N-phenylmaleimide terpolymer (SAM), and hard resins such as polystyrene. It is done. These may be used alone or in combination of two or more.

  Acrylonitrile-styrene copolymer is excellent because the molded product obtained has excellent balance of scratch resistance, impact resistance (especially low-temperature surface impact), molded appearance and colorability, and excellent moldability of the thermoplastic resin composition. One or more selected from the group consisting of a resin (SAN), an acrylonitrile-methyl methacrylate copolymer (MAN), and an acrylonitrile-styrene-methyl methacrylate terpolymer (MAS) resin is more preferable, and an acrylonitrile-styrene copolymer (SAN) and acrylonitrile-styrene-methyl methacrylate terpolymer (MAS) are more preferable.

The molecular weight of the vinyl polymer (B) is preferably 30,000 to 500,000 in terms of polystyrene-equivalent weight average molecular weight, taking into consideration the fluidity of the thermoplastic resin composition and the mechanical properties of the molded product, and 40,000 to 150,000 is more preferable, and 50,000 to 110,000 is more preferable.
The production of the vinyl polymer (B) is preferably performed by radical polymerization. The radical polymerization is performed by emulsion polymerization, solution polymerization, suspension polymerization, bulk polymerization, or the like.

<< thermoplastic resin composition >>
The thermoplastic resin composition of the present invention contains 1 to 99 parts by mass of the graft copolymer (A) and 1 to 99 parts by mass of the vinyl polymer (B), and the graft copolymer (A). What contains 5-80 mass parts and 20-95 mass parts of vinyl-type polymers (B) is preferable, Graft copolymer (A) 10-60 mass parts and vinyl-type polymer (B) 40-90 masses. (Wherein the total of the graft copolymer (A) and the vinyl polymer (B) is 100 parts by mass).

  The thermoplastic resin composition is usually prepared by a known mixing and kneading method, for example, a graft copolymer (A) and a vinyl polymer (B) in the form of powder, beads, or pellets, if necessary, dyes, pigments, various stable materials. A predetermined amount of additives such as an agent, a reinforcing agent, a filler, a flame retardant, and an antistatic agent are weighed and mixed, and the resulting mixture is melt kneaded. When melt-kneading, an extruder; a Banbury mixer, a pressure kneader, a kneader such as a roll, or the like may be used.

"Molding"
The molded article of the present invention is formed by molding the thermoplastic resin composition of the present invention.
Examples of the molding method include an injection molding method, an extrusion molding method, a blow molding method, a compression molding method, a calendar molding method, and an inflation molding method.
The molded product of the present invention has a fluidity as a raw material thermoplastic resin composition, and also satisfies scratch resistance, impact resistance, colorability, and surface appearance at the same time. It is particularly suitable for applications such as automobile exteriors and building materials that have design properties and impact resistance.

The present invention will be described more specifically with reference to examples and comparative examples. The present invention is not limited to the following examples. Unless otherwise specified,% and parts in the following examples are based on mass.
The mass average particle diameter of the graft copolymer in the latex in the production example was determined by a dynamic light scattering method using DLS-700 type manufactured by Otsuka Electronics Co., Ltd.
Further, the mass average molecular weight of the vinyl polymer was measured by GPC (gel permeation chromatography).

[Production Example 1]
Production of olefin-based rubbery polymer (G-1):
EPDM rubber (ethylene unit content 70%, propylene unit content 27%, containing 5% ethylidene norbornene unit as diene component) 87 parts, potassium oleate 2.6 parts as emulsifier, and low molecular weight acid-modified α-olefin system 13 parts of a polymer (manufactured by Mitsui Chemicals, Ltd., high wax 2203A, mass average molecular weight: 2700, acid value: 30 mg KOH / g) is rotated in the same direction with a rotating meshing twin screw extruder (Ikegai Iron Works, PCM-30) , L / D = 40) from a hopper at a rate of 4 kg / hour, and while continuously feeding a 20% potassium hydroxide aqueous solution at 110 g / hour from a feed port provided in the vent portion of the extruder, heating The temperature (cylinder temperature) is 190 ° C, the screw rotation speed is 250rpm, and continuously supplied to the cooling single screw extruder attached to the tip of the extruder, 90 ° C In it cooled and taken out. The taken-out solid was continuously diffused in hot deionized water to obtain a non-crosslinked olefin-based rubbery polymer latex. Subsequently, in a stainless steel autoclave equipped with a reagent injection container, a cooling tube, a jacket heater, a thermometer, and a stirrer, 100 parts of a non-crosslinked olefin rubber polymer latex (solid content) and 1.0 part of divinylbenzene , 1.0 part of a polymerization initiator (Nippon Yushi Co., Ltd., trade name “Perbutyl C”) was charged, heated to 80 ° C. with stirring, held for 30 minutes, further heated to 120 ° C., A cross-linked olefin rubber polymer (G-1) latex (gel content: 66%, mass average particle size: 420 nm) was obtained by reacting under stirring for 5 hours.

[Production Example 2]
Production of olefin-based rubbery polymer (G-2):
An olefin rubber-like polymer (G-2) latex (gel content 25%, mass average particle diameter 400 nm) was obtained in the same manner as in Production Example 1, except that the polymerization initiator was changed to 0.5 part. .

[Production Examples 3 to 12]
Production of graft copolymers (A-1) to (A-6) and (a-1) to (a-3):
In a stainless steel polymerization tank equipped with a reagent injection container, a cooling tube, a jacket heater, a thermometer, and a stirring device, 50 parts (solid content) of olefin rubber-like polymer latex shown in Table 1 and 290 parts of deionized water (olefin) System rubbery polymer latex containing water), potassium hydroxide 0.01 part, anhydrous sodium pyrophosphate 0.45 part, ferrous sulfate heptahydrate 0.01 part, dextrose 0.57 part, The internal temperature was 80 ° C. with stirring. Then, the monomer mixture shown in Table 1 (acrylonitrile (AN) and styrene (St)), an initiator (cumene hydroperoxide (CHP)) and a chain transfer agent (tertiary decyl mercaptan (t-DM)) are 210. Feed dropwise over a period of 0.4 minutes, while anhydrous sodium pyrophosphate 0.45 parts, ferrous sulfate heptahydrate 0.01 parts, dextrose 0.56 parts, sodium oleate 1.0 parts, deionized water 30 parts An aqueous solution consisting of the above was polymerized while being continuously added from another inlet for 210 minutes, and after completion of the dropwise addition, it was kept at an internal temperature of 80 ° C. for 30 minutes and then cooled to obtain a latex of a graft copolymer.
An antioxidant is added to the latex, coagulation treatment is performed with sulfuric acid, and after washing, dehydration, and drying steps, the milky white powdery graft copolymers (A-1) to (A-7), (a- 1) to (a-3) were obtained. Further, the reduced viscosity ηsp / C and the graft ratio of the obtained graft copolymer were measured. The results are shown in Table 1.

[Production Example 13]
Production of vinyl polymer (B-1):
27 parts of styrene, 25 parts of acrylonitrile and 48 parts of methyl methacrylate are polymerized by a known suspension polymerization method, and an acrylonitrile-styrene-methyl methacrylate terpolymer (MAS) having a polystyrene-reduced mass average molecular weight of 105,000 is obtained. Obtained.

[Examples 1-7 and Comparative Examples 1-5]
Graft copolymers (A-1) to (A-7), (a-1) to (a-3) and vinyl copolymer (B-1) were mixed in the proportions shown in Table 2 to release the release agent. After adding 0.4 parts of barium stearate, it was mixed thoroughly using a Henschel mixer. This was shaped with a twin-screw extruder set at a barrel temperature of 230 ° C. to produce pellets. The following evaluation was performed using the pellets. The results are shown in Table 2.

(Charpy impact strength)
A test piece for measuring Charpy impact strength (with a notch) was prepared by an injection molding method. After this test piece was left for 12 hours or more in an atmosphere of 23 ° C. or 0 ° C., Charpy impact strength of the test piece was measured by a method based on ISO179.

(HSI (High Speed Impact) surface impact strength)
About the test piece produced similarly to the test piece for Charpy impact strength measurement, Shimadzu Corporation make and HTM-1 type are used, speed | rate: 3.3m / sec, front-end | tip R: HSI surface impact strength on condition of 6.35mm. It was measured.

(Melt volume rate (MVR))
Measurement was performed under the conditions of a barrel temperature of 220 ° C. and a load of 98 N (10 kgf) by a method based on ISO 1133.
(Pencil hardness (scratch resistance))
A test specimen for measuring scratch resistance was prepared by an injection molding method. About this test piece, pencil hardness was measured by the method based on JISK5400.

(Colorability)
For a total of 100 parts of the graft copolymer (A) and the vinyl polymer (B), 1.0 part of a dye (Sumiplast Black 3BA-2, manufactured by Sumika Finechem Co., Ltd.), pigment (Mitsubishi Chemical ( Pellets containing 0.8 part of Mitsubishi Carbon # 2600 (carbon black)) and 0.4 part of a release agent (barium stearate) were prepared.
Using Toshiba Machine Co., Ltd.'s injection molding machine IS-100EN set to a cylinder temperature of 230 ° C. and a mold temperature of 60 ° C., pellets containing coloring materials were molded to produce a 100 mm × 100 mm × 3 mm black colored plate. . About this black colored board, the hue measurement based on JISZ8729 was performed.

(Molded appearance (flow mark))
About the shaping | molding board produced by the injection molding method, the glossiness, the compatibility defect, and generation | occurrence | production of the flow mark by molding gas were evaluated by visual determination. A good molded plate with no problems was evaluated as ◯, those with many problems that could not be put into practical use were evaluated as x, and the middle was evaluated as Δ.

From the examples and comparative examples, the following became clear.
1) The thermoplastic resin composition containing the graft copolymers (A-1) to (A-7) of Examples 1 to 7 has high scratch resistance and impact resistance of the obtained molded article, and is excellent in coloration. And has excellent fluidity. Therefore, a molded article made of these thermoplastic resin compositions is suitable for use in automobile exteriors and the like, and has high industrial utility value.
2) The thermoplastic resin composition of Comparative Example 1 using a graft copolymer (a-1) having a graft ratio of 64% as the graft copolymer has high fluidity, and the molded product is colored well. However, the scratch resistance and impact strength were greatly inferior. The molded product having such a low impact strength is difficult to be used for an application that requires a high level of impact resistance such as an automobile exterior, and thus has a low industrial utility value.

3) The thermoplastic resin composition of Comparative Example 2 using the graft copolymer (a-2) having a reduced viscosity ηsp / C of less than 0.35 dl / g as the graft copolymer has high fluidity. Although the molded product showed high scratch resistance and impact strength, the molded appearance and color development were inferior. Since such a molded article is difficult to be used in a light-colored color tone in which discoloration is conspicuous, such as an automobile exterior, the industrial utility value is low.
4) As the graft copolymer, the thermoplastic resin composition of Comparative Example 3 using the graft copolymer (a-3) having a graft ratio of significantly less than 65% has high fluidity and excellent molded products. Although exhibiting good colorability, the molding appearance, impact resistance, scratch resistance, and particularly impact strength at low temperatures were low. Since such a molded article is difficult to be used for an application that requires a high level of impact resistance such as an automobile exterior, the industrial utility value is low.

The thermoplastic resin composition and molded product thereof according to the present invention have the following remarkable effects, and their industrial utility value is extremely large.
1) The thermoplastic resin composition of the present invention has high fluidity, and the molded product satisfies all of high scratch resistance, high impact resistance, and good pigment colorability.
2) The balance of the above characteristics is a very high level that cannot be obtained by a conventionally known resin material containing, for example, a composite rubber composed of polyorganosiloxane and acrylate rubber as a rubbery polymer. The utility value is extremely high.

Claims (6)

The olefin rubber polymer (G) is grafted with at least one monomer selected from the group consisting of aromatic vinyl monomers, (meth) acrylic acid esters, and vinyl cyanide monomers. 1 to 99 parts by weight of the graft copolymer (A),
1 to 99 parts by mass of the vinyl polymer (B) (however, the total of the graft copolymer (A) and the vinyl polymer (B) is 100 parts by mass);
The graft ratio of the graft copolymer (A) is 65 to 90% by mass,
The thermoplastic resin composition whose reduced viscosity ((eta) sp / C) of the acetone soluble part of the said graft copolymer (A) is 0.35-0.60 dl / g.   The graft copolymer (A) is added to the olefin rubber-like polymer (G) with 80 to 60 parts by mass of an aromatic vinyl monomer and 20 to 40 parts by mass of a vinyl cyanide monomer (however, 2. The thermoplastic resin composition according to claim 1, which is a graft copolymer grafted with an aromatic vinyl monomer and a vinyl cyanide monomer in a total amount of 100 parts by mass.   The thermoplastic resin composition according to claim 1 or 2, wherein the olefin rubber-like polymer (G) has a gel content of 30 to 90 mass%.   The thermoplastic resin composition according to any one of claims 1 to 3, wherein the olefin rubber-like polymer (G) is produced by a mechanical emulsification method.   The olefin rubber-like polymer (G) is an ethylene-propylene rubber-like polymer (E) 80 to 99.9 parts by mass, and a low molecular weight acid-modified α-olefin polymer 0.1 to 20 parts by mass. (However, the total of the ethylene-propylene rubber-like polymer (E) and the low molecular weight acid-modified α-olefin polymer is 100 parts by mass), according to any one of claims 1 to 4. The thermoplastic resin composition as described. A molded article formed by molding the thermoplastic resin composition according to any one of claims 1 to 5.