JP2704304B2 - Thermoplastic resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermoplastic resin composition having excellent chemical resistance. More specifically, the present invention relates to a composition in which a specific amount of an epoxy group-containing olefin copolymer and a specific terpolymer are blended with a rubber-reinforced styrene resin.

(Conventional technology and problems) Generally, ABS resin, AES resin, AAS (ASA) resin and AC
BACKGROUND ART Rubber-reinforced styrene-based resins called S resins are widely used in a wide range of fields such as vehicles, light electric appliances, and miscellaneous goods because of their excellent mechanical properties such as impact resistance and workability, and excellent surface gloss.

However, it has poor chemical resistance as compared with other engineering plastics, and has a problem that cracks are easily generated when it comes into contact with gasoline, brake fluid, grease or the like.

It is already known that the chemical resistance is improved by increasing the amount of vinyl cyanide (acrylonitrile) in the resin. However, as the amount of acrylonitrile increases, the impact resistance decreases and the initial coloring (yellowing) occurs. Occurs. In addition, the present inventor has found improvement in chemical resistance by blending a terpolymer composed of olefin-unsaturated dicarboxylic anhydride-unsaturated carboxylic acid alkyl ester. With the development of functions, there has been a demand for the development of a composition having more excellent chemical resistance.

(Means for Solving the Problems) As a result of intensive studies on the improvement of the chemical resistance of the rubber-reinforced styrenic resin, the present inventors have obtained a synergistic effect by using two specific copolymers in combination, and have obtained an excellent effect. The inventors have found that a chemical resistant composition can be provided, and have reached the present invention.

That is, the present invention provides a rubber-reinforced styrenic resin (A)
Per 100 parts by weight, 0.1 to 40 parts by weight of an epoxy group-containing olefin copolymer (B) comprising an unsaturated epoxy compound and an olefin or an ethylenically unsaturated compound and an unsaturated dicarboxylic anhydride, an olefin and an unsaturated carboxylic acid An object of the present invention is to provide a thermoplastic resin composition comprising 0.1 to 40 parts by weight of a terpolymer (C) comprising an acid alkyl ester and having excellent chemical resistance.

Hereinafter, the thermoplastic resin composition of the present invention will be described in detail.

The rubber-reinforced styrene resin (A) in the present invention is:
A graft copolymer obtained by polymerizing an aromatic vinyl compound and another copolymerizable vinyl compound as required in the presence of a rubbery polymer or the graft copolymer, and an aromatic vinyl compound And a mixture with an aromatic vinyl polymer obtained by polymerizing another copolymerizable vinyl compound as required.

Examples of the rubbery polymer constituting the rubber-reinforced styrene resin (A) include diene rubbery polymers such as polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, ethylene-propylene copolymer, and ethylene-propylene copolymer. Non-diene rubber-like polymers such as propylene-non-conjugated diene copolymer, acrylic rubber-like polymer, and chlorinated polyethylene are exemplified, and one or more kinds can be used. These rubbery polymers are produced by emulsion polymerization, solution polymerization, bulk polymerization, suspension polymerization and the like.

The particle size and gel content of the rubbery polymer in the case of production 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.
%.

Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene, α-methylvinyltoluene, dimethylstyrene, chromestyrene, and dichlorostyrene. , Bromstyrene, dibromostyrene, and the like, and one or more kinds can be used. Particularly, styrene and α-methylstyrene are preferred.

Other vinyl compounds copolymerizable with an aromatic vinyl compound include vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, and ethyl methacrylate. , Propyl methacrylate, unsaturated carboxylic acid alkyl esters such as 2-ethylhexyl methacrylate, and maleimide compounds such as maleimide, N-phenylmaleimide, N-methylmaleimide, and N-cyclohexylmaleimide. Can be. Particularly, acrylonitrile, methyl methacrylate and N-phenylmaleimide are preferred.

As the graft polymerization method, a known emulsion polymerization, suspension polymerization, bulk polymerization, solution polymerization or a method combining these is used.

The aromatic vinyl compound and other copolymerizable vinyl compounds constituting the aromatic vinyl polymer used by being mixed with the graft copolymer are the same groups as those used for the graft copolymer. Any one or two from
More than one species can be selected and used. As the polymerization method of the polymer, known emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, or a combination thereof can be used.

The composition ratio of the rubbery polymer and the compound in the rubber-reinforced styrene resin (A) is not limited, but is preferably 20 to 80% by weight of the rubbery polymer and 80 to 20% by weight of the compound. The composition ratio of the aromatic vinyl compound to the other vinyl compound in such a compound is not particularly limited, but is 10 to 100% by weight, particularly 30 to 70% by weight of the aromatic vinyl compound, and other vinyl compounds. 90 to 0% by weight, especially 70 to 30% by weight is preferred.

Next, the epoxy group-containing olefin copolymer (B) used in the present invention is an unsaturated epoxy compound and an olefin, or a copolymer of these and an ethylenically unsaturated compound. Although there is no particular limitation on the composition ratio of the epoxy group-containing olefin copolymer, the unsaturated epoxy compound
Preferably it is 0.05 to 95% by weight.

The unsaturated epoxy compound is a compound having an unsaturated group capable of copolymerizing with an olefin and an ethylenically unsaturated compound and an epoxy group in the molecule.

For example, unsaturated epoxy compounds such as unsaturated glycidyl esters, unsaturated glycidyl ethers, epoxyalkenes and P-glycidylstyrenes represented by the following general formulas (I), (II) and (III). .

(R is a hydrocarbon group of C ₂ -C ₁₈ having an ethylenically unsaturated bond.) (R is a hydrocarbon group of C ₂ -C ₁₈ having an ethylenically unsaturated bond.) X is It is. ) (R is a C ₂ -C ₁₈ hydrocarbon group having an ethylenically unsaturated bond; R ′ is hydrogen or a methyl group.) Specifically, glycidyl acrylate, glycidyl methacrylate, glycidyl itaconate, butene Carboxylic esters, allyl glycidyl ether, 2
-Methylallyl glycidyl ether, styrene-P-glycidyl ether, 3,4-epoxybutene, 3,4-epoxy-3-methyl-1-butene, 3,4-epoxy-1-pentene, 3,4-epoxy- Examples thereof include 3-methylpentene, 5,6-epoxy-1-hexene, vinylcyclohexene monoxide, and P-glycidylstyrene, and one or more kinds thereof can be used. Particularly, glycidyl alcohol or glycidyl methacrylate is preferred.

Examples of the olefin include ethylene, propylene, butene, pentene, and the like, and one or more kinds can be used. Particularly, ethylene and propylene are preferable.

Examples of the ethylenically unsaturated compound include vinyl esters containing C _{2 to} C ₆ as a saturated carboxylic acid component, acrylic and methacrylic esters and maleic esters containing C _{1 to} C ₈ as a saturated alcohol component, and halogens. And vinyl chlorides.

These ethylenically unsaturated compounds are used in the copolymerization of the unsaturated epoxy compound and the olefin with respect to all the compounds.
Less than 50% by weight, especially 0.1 to 45% by weight, is copolymerized.

The epoxy group-containing olefin copolymer (B) is obtained by copolymerizing an unsaturated epoxy compound with an olefin and, if necessary, an ethylenically unsaturated compound, or copolymerizing an olefin polymer or an olefin with an ethylenically unsaturated compound. It is produced by graft copolymerizing an unsaturated epoxy compound in the presence of

Preferred examples of the epoxy group-containing olefin copolymer (B) include ethylene-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, ethylene-methyl methacrylate, glycidyl methacrylate copolymer, and polyethylene and polypropylene. , Poly-1-butene, poly-4-methyl-
Copolymers obtained by grafting glycidyl methacrylate in the presence of olefin polymers such as pentene-1, ethylene-propylene copolymer, and ethylene-propylene-diene copolymer are exemplified.

As a method for producing the epoxy group-containing olefin copolymer (B), an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, a solution polymerization method, or a polymerization method in combination thereof is used.

The terpolymer (C) constituting the thermoplastic resin composition of the present invention is a copolymer comprising an unsaturated dicarboxylic anhydride, an olefin and an unsaturated carboxylic acid alkyl ester. The composition of the terpolymer (C) is not particularly limited. However, from the viewpoint of chemical resistance and thermal stability, the unsaturated dicarboxylic anhydride is 0.5 to 10% by weight, particularly 1 to 8% by weight, and the olefin 50 to 50%. Preference is given to 98.5% by weight, in particular 55 to 96% by weight and 1 to 40% by weight, in particular 3 to 37% by weight, of unsaturated carboxylic acid alkyl esters.

Examples of the unsaturated dicarboxylic anhydride include maleic anhydride, citraconic anhydride, aconitic anhydride, and the like, and one or more kinds can be used. Particularly, maleic anhydride is preferred.

Examples of the olefin include ethylene, propylene, butene-1, 4-methylpentene-1, and the like, and one or more kinds thereof can be used. Particularly, ethylene and propylene are preferable.

As the unsaturated carboxylic acid alkyl ester, methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, butyl (meth) acrylate, hydroxymethyl (meth) acrylate and the like can be mentioned, and one or more kinds can be used. Particularly, ethyl acrylate and butyl acrylate are preferable.

The terpolymer (C) can be produced by various methods. For example, olefin is supplied to a first zone of a cylindrical autoclave equipped with a blade-type stirrer, and then a monomer mixture of olefin, unsaturated dicarboxylic anhydride, and unsaturated carboxylic acid alkyl ester is supplied to a second zone. Further, a radical initiator such as t-butyl 2-ethyl-perhexanoate dissolved in the hydrocarbon fraction is injected into the third zone.
There is a method of polymerizing under a pressure of 1000 to 2000 atm.

The thermoplastic resin composition of the present invention comprises 100 parts by weight of the rubber-reinforced styrene resin (A) described above, 0.1 to 40 parts by weight of the epoxy group-containing olefin copolymer (B), and 0.1 to 40 parts by weight of the terpolymer (C). Consists of 40 parts by weight.

If the copolymer (B) and / or (C) is less than the lower limit, sufficient chemical resistance can be obtained, and if it exceeds the upper limit, thermal stability and rigidity decrease, which is not preferable.

Particularly, an epoxy group-containing olefin polymer (B) 0.5 to 20
Parts by weight and 0.5 to 20 parts by weight of the terpolymer (C) are preferred.

The rubber content (rubber component derived from the rubber-reinforced styrene resin) in the composition is preferably from 10 to 30% by weight from the viewpoint of the balance of physical properties of the composition.

The method of mixing the rubber-reinforced styrene resin (A), the epoxy group-containing olefin copolymer (B) and the terpolymer (C) is not particularly limited, and may be in the form of a latex or powder, beads, pellets or the like. Can be mixed in a state. The order of mixing them is also not particularly limited, and may be any of a method of batch-mixing three components and a method of predictively mixing two components and then mixing the remaining one component. As the melt-kneading method, known methods such as a Banbury mixer, a roll, and an extruder can be used.

In addition, at the time of mixing, additives such as an antioxidant, an ultraviolet absorber, an antistatic agent, a lubricant, a dye, a pigment, a plasticizer, a flame retardant, and a release material can be blended as necessary. In addition, thermoplastic resins such as polyacetal, polycarbonate, polybutylene terephthalate, polyphenylene oxide, polymethyl methacrylate, and polyvinyl chloride can be appropriately compounded.

Next, the present invention will be specifically described with reference to Examples and Comparative Examples. In addition, the number of parts and the percentage are all shown on a weight basis.

Reference Example-1 Rubber-reinforced styrene-based resin (A) ABS-1: A polybutadiene rubber latex having a weight-average particle diameter of 0.43 μm and a gel content of 85% (solid component) by a known emulsion polymerization method.
50%) 100 parts, 35 parts of styrene and 15 parts of acrylonitrile
The parts were subjected to graft polymerization to obtain a graft copolymer having a rubber content of about 50%.

By a known suspension polymerization method, a copolymer having a styrene of 71%, acrylonitrile of 29% and an intrinsic viscosity of 0.65 (30 ° C., dimethylformamide or less, same) was mixed with a graft copolymer, and a rubber content of 12% was obtained. Was obtained.

ABS-2: α-methylstyrene 70% by a known emulsion polymerization method,
After obtaining a copolymer having 30% acrylonitrile and an intrinsic viscosity of 0.58, it was mixed with the graft copolymer used for ABS-1 to obtain an ABS resin having a rubber content of 15%.

ABS-3: By a known emulsion polymerization method, styrene 50%, N-phenylmaleimide 30%, acrylonitrile 20%, intrinsic viscosity 0.
After obtaining the copolymer No. 63, it was mixed with the graft copolymer used for ABS-1 to obtain an ABS resin having a rubber content of 15%.

AES: 43% propylene, iodine value by known solution polymerization method
13 ethylene-propylene-ethylidene norbornene 10
0 parts, styrene 400 parts and acrylonitrile 170 parts were subjected to graft polymerization to obtain AES having a rubber content of about 15%.

Reference Example 2 Production of Epoxy Group-Containing Olefin Copolymer (B) An epoxy group-containing olefin copolymer having the following composition was produced by a bulk polymerization method using an autoclave-type polyethylene production apparatus according to the polymerization conditions of high-pressure polyethylene. .

B-1 Ethylene-glycidyl methacrylate-vinyl acetate copolymer (composition ratio 90-7-3) B-2 Ethylene-glycidyl methacrylate copolymer (composition ratio 90-10) Reference Example-3 Terpolymer (C C-1) Using a cylindrical autoclave equipped with a blade-type stirrer, t-butyl 2-ethyl- dissolved in a hydrocarbon fraction was used.
In the presence of perhexanoate, polymerize the monomer mixture at 185 ° C and 1600 atm, ethylene 60%, maleic anhydride 4.5%
And terpolymer C-1 containing 35.5% of ethyl acrylate
And a terpolymer C-2 of 92% ethylene, 1.5% maleic anhydride and 6.5% ethyl acrylate.

C-3 A terpolymer of 70% ethylene, 4% maleic anhydride and 26% butyl acrylate was obtained in the same manner as in C-1 and C-2.

Examples and Comparative Examples The rubber-reinforced styrenic resin (A), epoxy group-containing olefin copolymer (B) and terpolymer (C) obtained by the above-mentioned method are blended as shown in Tables 1 to 3. And melt-mixed and granulated using a 40 mm twin screw extruder.

The physical properties of the obtained composition were measured by the following methods, and the results are shown in Tables 1 to 3.

The test piece for measuring physical properties was molded using a 3.5 oz injection molding machine.

Chemical resistance ・ Brake fluid 150mm × 20mm × 3 from injection molded flat plate of 150mm × 90mm × 3mm
mm test piece was cut out and a cantilevered burr jig (Japanese Patent Laid-Open No.
251 gazette, page 3), apply Honda Brake Fluid DOT-3, and leave for 3 minutes. The distance (Xc) from the maximum deflection point to the crack occurrence point is measured, and the critical strain (%) is determined based on the following equation.

h: Thickness of test piece, 3mm δ: Maximum deflection, 30mm l: Distance from fixed end to maximum deflection point, 100mm ・ PVC sheet As in the previous section, cut out the test piece and set P on one side with a degree of polymerization of 700.
A soft PVC sheet (150 mm x 20 mm x 2 mm) prepared by adding 70 parts by weight of dioctyl phthalate to 100 parts by weight of VC is placed and fixed from above the sheet with an adhesive tape. After fixing the flexible PVC sheet / test piece composite sheet to the cantilever burr jig,
Leave for 9 days.

 The critical strain (%) is determined in the same manner as in the previous section.

Impact resistance After preparing a 150mm x 90mm x 3mm test piece, measure the Du Pont impact strength (kgcm) in a room conditioned at 23 ° C.

Workability 210 ° C, 30 kg / cm ² or 2 using a high-quality flow tester
The outflow rate (cc / min) at 30 ° C and 60 kg / cm ² was measured. The shape of the die is 1 mm in diameter and 10 mm in length.

(Effect of the Invention) The present invention has an effect that a composition having excellent chemical resistance can be provided as compared with a conventional (heat-resistant) rubber-reinforced styrene resin.

────────────────────────────────────────────────── (5) Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 23:02) (56) References JP-A-3-217432 (JP, A) JP-A-3 JP-A-95252 (JP, A) JP-A-2-127452 (JP, A) JP-A-2-29451 (JP, A) JP-A-1-113452 (JP, A) JP-A-64-56762 (JP, A) JP-A-63-68657 (JP, A) JP-A-61-163952 (JP, A)

Claims (1)

(57) [Claims] 1. An epoxy group-containing olefin copolymer (B) comprising 0.1 to 40 parts by weight of an unsaturated epoxy compound and an olefin or an ethylene-based unsaturated compound and 100 parts by weight of a rubber-reinforced styrene resin (A). And a terpolymer (C) comprising an unsaturated dicarboxylic acid anhydride, an olefin and an alkyl carboxylic acid unsaturated ester in an amount of 0.1 to 4
A thermoplastic resin composition comprising 0 parts by weight.