JPH0725983B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a thermoplastic resin composition which is excellent in impact resistance and flowability, and gives a uniformly matte surface of a molded article at the time of molding.

<Prior art> Rubber-reinforced styrene resin represented by ABS resin has excellent mechanical properties such as impact resistance and rigidity and workability, as well as excellent appearance of molded products such as gloss. It is used for a wide range of purposes such as sundries. However, in recent years
From the viewpoint of safety mainly for automobile interior parts, or in order to obtain a matte calm texture, there is an increasing demand for a matte material having a low gloss. Conventional methods for delustering rubber-reinforced styrenic resins include (i) addition of inorganic fillers such as calcium carbonate, (ii) addition of rubbery polymer, and (iii) introduction by copolymerization of ethylenically unsaturated carboxylic acid. , (Iv) the addition of an epoxy group-containing olefin copolymer has been proposed.

<Problems to be Solved by the Invention> In the above-mentioned matting method, (i) the addition of the inorganic filler is
There is a drawback that the impact resistance, which is a characteristic of rubber-reinforced resin, is significantly reduced. Also, (ii) addition of a rubber-like polymer causes defects such as flow marks on the surface of the molded product, resulting in a uniform matte surface. There is a problem that it cannot be obtained, and the addition of (iii) ethylenically unsaturated carboxylic acid and (iv) epoxy group-containing olefin copolymer is more excellent in matting effect than the above methods (i) and (ii). However, there is a problem that the impact strength or flowability of the resin decreases depending on the amount added.

<Means for Solving Problems> As a result of intensive studies to improve the above problems, the present inventors have mixed a rubber-reinforced styrene-based resin with a specific modified copolymer at a specific ratio, The inventors have found that a thermoplastic resin composition having a good balance between impact strength and flowability and providing a uniform matte surface of a molded article can be obtained, and arrived at the present invention.

That is, the present invention includes (A) a rubber-reinforced styrene resin, (B) 0.1 to 20% by weight of vinyl oxazoline, 50 to 89.9% by weight of an aromatic vinyl monomer, and 49.9% of another vinyl monomer which can be copolymerized. To 10% by weight of an oxazoline-modified copolymer, (C) a monomer having a functional group reactive with an oxazoline group
0.1-20% by weight, aromatic vinyl monomer 50-89.9% by weight
And other copolymerizable vinyl monomers 49.9-10% by weight
And (B) 0.1 to 30 parts by weight and (C) 0 to 30 parts by weight per 100 parts by weight of (A) a thermoplastic resin composition. It is to provide things.

The present invention will be described in detail below.

The rubber-reinforced styrene-based resin (A) in the present invention is obtained by polymerizing an aromatic vinyl-based monomer in the presence of a rubber-like polymer and other vinyl-based monomer copolymerizable as necessary. A graft copolymer or a graft copolymer thereof,
It is a mixture with an aromatic vinyl-based polymer obtained by polymerizing an aromatic vinyl-based monomer and optionally another copolymerizable vinyl-based monomer.

As the rubber-like polymer used in the graft copolymer,
Diene rubber-like polymers such as polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer and ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, acrylic rubber-like polymer, chlorine Examples of the non-diene rubbery polymer such as modified polyethylene can be used alone or in combination of two or more. These rubbery polymers are produced by emulsion polymerization, solution polymerization, suspension polymerization, bulk polymerization and the like.

The particle size and gel content of the rubber-like polymer when produced by emulsion polymerization are not particularly limited, but the average particle size is 0.1 to 1 μm and the gel content is 0 to 95%.
Is preferred.

Aromatic vinyl monomers include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, t-butylstyrene, α-methylvinyltoluene, dimethylstyrene, chlorostyrene,
Examples thereof include dichlorostyrene, bromostyrene, and dibromostyrene, which may be used alone or in combination of two or more.

Other vinyl monomers copolymerizable with the aromatic vinyl monomer include vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. Unsaturated carboxylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, and 2-ethylhexyl methacrylate, maleimide, N-phenylmaleimide, N-methylmaleimide, N-cyclohexylmaleimide, and other maleimide-based monomers are exemplified. They can be used alone or in combination of two or more.

As the graft polymerization method, known emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization or a combination thereof may be used.

The aromatic vinyl-based monomer constituting the aromatic vinyl-based polymer used by mixing with the graft copolymer and the other copolymerizable vinyl-based monomer are each used in the graft copolymer. Any one kind or two or more kinds can be selected and used from the same group. As the polymerization method of the polymer, known emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, or a combination thereof may be used.

The oxazoline-modified copolymer (B) used in the present invention means vinyl oxazoline 0.1 to 20% by weight, aromatic vinyl monomer 50 to 89.9% by weight, and other copolymerizable vinyl monomer 49.9 to It is a copolymer composed of 10% by weight.

As vinyl oxazoline, 2-vinyl-2-oxazoline, 5-methyl-2-vinyl-2-oxazoline,
4,4-Dimethyl-2-vinyl-2-oxazoline, 4,4-
Dimethyl-2-vinyl-5,6-dihydro-4H-1,3-oxazine, 4,4,6-trimethyl-2-vinyl-5,6-dihydro-4H-1,3-oxazine, 2-isopropenyl -2-
Oxazoline, 4,4-dimethyl-2-isopropenyl-
2-oxazoline etc. are illustrated, and it is used by 1 type (s) or 2 or more types. Particularly preferred is 2-vinyl-2-oxazoline.

If the amount of vinyl oxazoline is less than 0.1% by weight, sufficient mattness cannot be obtained, and if it exceeds 20% by weight, the flowability is deteriorated, which is not preferable.

Examples of the aromatic vinyl-based monomer and the other copolymerizable vinyl-based monomer are the same as those exemplified in the section of the graft copolymer, and they are used alone or in combination of two or more. It is preferable.

There is no particular limitation on the molecular weight of the copolymer (B),
The weight average molecular weight is preferably 10,000 to 1,000,000.

The copolymer (C) used in the present invention is a monomer having a functional group reactive with an oxazoline group, that is, a functional group capable of reacting with the oxazoline group in the oxazoline-modified copolymer (B) 0.1 It is a copolymer composed of 20 to 20% by weight, 50 to 89.9% by weight of an aromatic nibiyl monomer, and 49.9 to 10% by weight of another copolymerizable vinyl monomer. The functional group having reactivity with oxazoline is an amino group, a carboxyl group, an acid anhydride group, an epoxy group, a mercapto group,
Examples thereof include an isocyanate group, a halogen group and a hydroxyl group.

The monomer having an amino group is acrylamide,
Methacrylamide, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, etc., as a monomer having a carboxyl group, acrylic acid, methacrylic acid, maleic acid, phthalic acid, fumaric acid, itaconic acid, etc.
As the monomer having an acid anhydride group, maleic anhydride, phthalic anhydride, itaconic anhydride, etc., as the monomer having an epoxy group, glycidyl acrylate, glycidyl methacrylate, glycidyl itaconic acid, etc., a unit amount having an isocyanate group As the body, vinyl isocyanate, etc., as the monomer having a halogen group, vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, vinylidene fluoride, etc., as the monomer having a hydroxyl group, hydroxyethyl acrylate, hydroxyethyl Examples of the monomer having a mercapto group such as methacrylate, o-, m- or p-hydroxystyrene include vinyl mercaptan and the like, and they may be used alone or in combination of two or more.

Among these, a monomer having a carboxyl group, an acid anhydride group and an epoxy group is particularly preferable.

The amount of the monomer having a functional group reactive with oxazoline is 0.
If it is less than 1% by weight, the reactivity with the oxazoline group is inferior, which is not preferable. If it exceeds 20% by weight, the flowability of the finally obtained composition is inferior.

Examples of the aromatic vinyl-based monomer and the other copolymerizable vinyl-based monomer are the same as those exemplified in the section of the graft copolymer, and they may be used alone or in combination of two or more. You can

There is no particular limitation on the molecular weight of the copolymer (C),
The weight average molecular weight is preferably 10,000 to 1,000,000.

As the polymerization method of the copolymers (B) and (C), known emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization or a combination thereof may be used.

The thermoplastic resin composition of the present invention comprises the rubber-reinforced styrene resin (A), the oxazoline-modified copolymer (B) and the copolymer (C) described above, and the composition ratio thereof is (A) 100.
(B) 0.1 to 30 parts by weight and (C) 0 to 3 per part by weight
It is 0 parts by weight, and if it is out of this range, the balance of impact strength, flowability and matting level is poor, which is not preferable.

Preferably, (B) 0.5 to 25 parts by weight and (C) 0 to 25 parts by weight per 100 parts by weight of (A).

The method for mixing the rubber-reinforced styrene resin (A), the oxazoline-modified copolymer (B) and the copolymer (C) is not particularly limited, and they are mixed in a latex state or in a state of powder, beads, pellets or the like. I can do things. The order of mixing them is also not particularly limited, and may be a method of collectively mixing the three components or a method of premixing the two components and mixing the remaining one component. As a melt-kneading method, a known method such as a Banbury mixer, a roll or an extruder can be adopted.

At the time of mixing, if necessary, an antioxidant, an ultraviolet absorber, an antistatic agent, a lubricant, a dye, a pigment, a plasticizer, a flame retardant,
Additives such as release agents can be added. Further, a thermoplastic resin such as polyacetal, polycarbonate, polybutylene terephthalate, polyphenylene oxide, polymethylmethacrylate, or polyvinyl chloride can be appropriately blended.

Next, the present invention will be specifically described with reference to Examples and Comparative Examples. The numbers of parts and percentages are shown on a weight basis.

Reference Example 1. Production of Oxazoline Modified Copolymer (B) B-1: Copolymer of 1 part 2-vinyl-2-oxazoline, 28 parts acrylonitrile and 71 parts styrene having an intrinsic viscosity of 0.56 by a known solution polymerization method. Was manufactured. The intrinsic viscosity was measured at 30 ° C. in dimethylformamide. (Unit: 10
0 ml / g) In the same manner as B-2: B-1, a copolymer of 5 parts of 2-vinyl-2-oxazoline, 30 parts of acrylonitrile and 65 parts of styrene and having an intrinsic viscosity of 0.55 was produced.

B-3: A copolymer of 15 parts of 2-vinyl-2-oxazoline, 26 parts of acrylonitrile and 59 parts of styrene and having an intrinsic viscosity of 0.53 was produced in the same manner as in B-1.

B-4: In the same manner as in B-1, a copolymer of 25 parts of 2-vinyl-2-oxazoline, 23 parts of acrylonitrile and 52 parts of styrene and having an intrinsic viscosity of 0.54 was produced.

Reference Example 2. Production of Copolymer (C) C-1: Intrinsic viscosity of 5 parts of methacrylic acid, 30 parts of acrylonitrile and 65 parts of styrene by a known emulsion polymerization method.
56 copolymers were prepared.

C-2: A copolymer of 15 parts of methacrylic acid, 26 parts of acrylonitrile and 59 parts of styrene and having an intrinsic viscosity of 0.55 was produced in the same manner as C-2.

C-3: A copolymer having an intrinsic viscosity of 0.55 composed of 5 parts of glycidyl methacrylate, 30 parts of acrylonitrile and 65 parts of styrene was produced by a known solution polymerization method.

After precipitation of B-1 to B-4 and C-3 in methanol,
It was separated and collected. C-1 and C-2 were recovered by salting out with calcium chloride, dehydration and drying.

As the rubber-reinforced styrene resin (A), A-1: "ABS resin" made by Sumitomo Nogatac Co., Ltd. Clarastic KU-600 A-2: "AES resin" made by Sumitomo Nogatak Co., Ltd. Unibright UB-500 was used.

Example A rubber-reinforced styrene resin (A), an oxazoline-modified copolymer (B) and a copolymer (C) were mixed in a composition shown in Table 1 and melt-mixed using a 40 mm twin-screw extruder. Granulated. The granulation temperature was set to 280 ° C.

The physical properties of the obtained resin composition were measured by the following methods, and the results are shown in Table 1.

○ Impact strength (notched Izod): ASTM D-256 ○ Flowability: High-performance flow tester ○ Surface gloss and unevenness of gloss: Mold a test piece of 60 mm × 60 mm, thickness 3 mm, and squeeze the gloss in the center of the test piece. It was measured at an incident angle of 60 degrees by using a digital variable angle gloss meter UGV-4D manufactured by Testing Machine Co., Ltd. The unevenness of gloss on the surface of the test piece was evaluated by visual judgment.

The above test pieces for quality evaluation were molded using a 3.5 ounce injection molding machine with the cylinder temperature set at 260 ° C.

<Examples 1 to 6, Comparative Examples 1 and 2> The effects of the copolymer (C) are shown.

<Examples 7 to 10 and Comparative Examples 3 to 8> The influence of the amount of the oxazoline-modified copolymer (B) is shown.

<Examples 11 to 12, Comparative Examples 9 to 10> The influence of the type of the rubber-reinforced styrene resin (A) is shown.

<Effects of the Invention> The resin composition of the present invention is superior in impact strength and flowability to the matte level of the molded article and has a uniform matte without uneven gloss, as compared with the conventional matte resin composition. The feature is that a surface is obtained.

Claims (1)

[Claims] 1. A rubber-reinforced styrene-based resin (A), (B) 0.1 to 20% by weight of vinyl oxazoline, 50 to 89.9% by weight of an aromatic vinyl-based monomer, and 49.9% of another copolymerizable vinyl-based monomer. To 10% by weight of an oxazoline-modified copolymer, (C) a monomer having a functional group reactive with an oxazoline group
0.1-20% by weight, aromatic vinyl monomer 50-89.9% by weight
And a copolymer composed of 49.9 to 10% by weight of other copolymerizable vinyl monomer, (B) 0.1 to 30 parts by weight and (C) 0 to 30 parts by weight per 100 parts by weight of (A). Thermoplastic resin composition characterized by being blended