JPH08143725A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE: To obtain a thermoplastic resin composition having good surface delamination resistance and chemical resistance and being excellent in a balance between impact resistance and processability by mixing specified acid-modified resins with a specified copolymer. CONSTITUTION: This composition is prepared by mixing 20-80 pts.wt. acid- modified styrene resin (A) prepared by polymerizing 20-94.9wt.% aromatic vinyl monomer, 5-60wt.% vinyl cyanide monomer and 0.1-20wt.% α, β-unsaturated carboxylic acid monomer in the presence or absence of a rubbery polymer with 20-80 pts.wt. (the total of components A and B is 100 pts.wt.) acid-modified polyolefin (B) prepared by grafting 0.01-5 pts.wt. α, β-unsaturated carboxylic acid monomer onto 100 pts.wt. polyolefin and 0.1-20 pts.wt. epoxy olefin copolymer (C). A desirable example of component C is a copolymer of 0.05-95wt.% unsaturated epoxy compound with 5-99.5wt.% olefin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition having excellent surface layer peeling resistance and chemical resistance, and having an excellent balance of impact resistance and processability.

[0002]

2. Description of the Related Art Styrenic resins such as ABS, AES, and AS resins are widely used as typical general-purpose resins, but there is a problem that they have insufficient chemical resistance, moldability, and heat resistance. On the other hand, olefin resins such as polypropylene and polyethylene have excellent mechanical strength, moldability, chemical resistance and the like, and are used in various fields. By blending styrene resin and olefin resin,
Various proposals have been made to obtain a composition having excellent chemical resistance, mechanical strength, and moldability, but since styrene resins and olefin resins are originally incompatible, delamination occurs even when blended. However, there is a problem that excellent mechanical strength cannot be obtained.

[0003]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventors have found that a composition obtained by blending an acid-modified styrene resin and an acid-modified polyolefin with a specific copolymer is The present invention has been accomplished by finding that it does not cause delamination and has excellent chemical resistance and excellent impact resistance-workability balance.

That is, according to the present invention, in the presence or absence of (A) a rubbery polymer, the aromatic vinyl monomer 20 to
94.9% by weight, vinyl cyanide-based monomer 5 to 60% by weight and α, β-unsaturated carboxylic acid-based monomer 0.1 to 2
Acid-modified styrenic resin 20 to 8 obtained by polymerizing 0% by weight
20 to 80 parts by weight of an acid-modified polyolefin obtained by graft-reacting 0.01 to 5 parts by weight of an α, β-unsaturated carboxylic acid monomer with respect to 0 parts by weight and (B) 100 parts by weight of a polyolefin. (A) + (B) = 100 parts by weight], 0.1 to 20 parts by weight of (C) an epoxy group-containing olefin copolymer is blended, which does not cause delamination and has excellent chemical resistance, And a thermoplastic resin composition having an excellent impact resistance-processability balance. The thermoplastic resin composition of the present invention will be described in detail below.

The acid-modified styrenic resin used in the thermoplastic resin composition of the present invention means an aromatic vinyl-based monomer, a vinyl cyanide-based monomer and a vinyl-based cyanide monomer in the presence or absence of a rubber-like polymer. It is a polymer obtained by polymerizing an α, β-unsaturated carboxylic acid monomer.

Examples of the rubbery polymer include polybutadiene rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR) and other diene rubbers.
Ethylene-propylene rubber, ethylene-propylene-non-conjugated diene (ethylidene norbornene, dicyclopentadiene, etc.) rubber and other ethylene-propylene rubber, polybutyl acrylate and other acrylic rubber, and the like, and one or more kinds to be used. You can Diene rubber is particularly preferable. Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, paramethylstyrene, chlorostyrene, and bromstyrene, and one or more of them can be used. Especially styrene, α-
Methylstyrene is preferred. Examples of the vinyl cyanide monomer include acrylonitrile and methacrylonitrile, and one kind or two or more kinds can be used. Acrylonitrile is particularly preferred. Examples of the α, β-unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, maleic anhydride, itaconic anhydride, glutaconic anhydride, citraconic anhydride, and anicocot anhydride. And one kind or two or more kinds can be used. Acrylic acid and methacrylic acid are particularly preferable.

The composition ratio of each monomer in the monomers is 20 to 94.9% by weight of an aromatic vinyl monomer, 5 to 60% by weight of a vinyl cyanide monomer, and an α, β-unsaturated carboxylic acid. The amount of the system monomer is 0.1 to 20% by weight. If the amount of the aromatic vinyl monomer is less than 20% by weight, the processability is poor and the color is yellow, and if it exceeds 94.9% by weight, impact resistance is deteriorated and surface layer peeling is not preferable. Vinyl cyanide monomer is 5
If it is less than wt%, the impact resistance is lowered, and if it exceeds 60 wt%, it is colored undesirably. Further, when the content of the α, β-unsaturated carboxylic acid monomer is less than 0.1% by weight, delamination occurs, and when it exceeds 20% by weight, workability is deteriorated. Surface layer peeling resistance and impact resistance of the final composition, processability, heat resistance,
Aromatic vinyl monomer 40-
Particularly preferred are 89.8% by weight, 10 to 50% by weight of vinyl cyanide monomer, and 0.2 to 10% by weight of α, β-unsaturated carboxylic acid monomer.

There is no limitation on the composition ratio of the rubber-like polymer and the total amount of monomers (aromatic vinyl monomer, vinyl cyanide monomer and α, β-unsaturated carboxylic acid type monomer). From the viewpoint of the balance of surface layer peeling resistance and impact resistance of the final composition, processability, heat resistance, and chemical resistance, particularly impact resistance, 10 to 70% by weight of rubber-like polymer, total of 90 monomers. It is preferably ˜30% by weight.

The acid-modified styrenic resin can be produced by known polymerization methods such as emulsion polymerization, suspension polymerization, bulk polymerization, solution polymerization and combinations thereof.

The acid-modified polyolefin in the present invention means 0.01 to 5 with respect to 100 parts by weight of the polyolefin.
It is a polymer obtained by carrying out a graft reaction of parts by weight of an α, β-unsaturated carboxylic acid monomer.

Examples of the polyolefin include polypropylene, polyethylene (high density, medium density, linear low density, ultra low density, high pressure method low density), ethylene-propylene copolymer, ethylene-butene copolymer and the like. Alternatively, two or more kinds can be used. Especially polypropylene,
Polyethylene is preferred.

Examples of the α, β-unsaturated carboxylic acid type monomers include acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, maleic anhydride, itaconic anhydride, glutaconic anhydride, citraconic anhydride, and anhydrous. Anicotic acid and the like can be used, and one kind or two or more kinds can be used.
Maleic anhydride is particularly preferable.

The amount of the α, β-unsaturated carboxylic acid monomer grafted is 0.0 with respect to 100 parts by weight of the polyolefin.
It is in the range of 1 to 5 parts by weight, more preferably 0.1 to 5 parts by weight.
4 parts by weight. If the graft amount is less than 0.01 parts by weight, the reaction between the acid-modified polyolefin and the acid-modified styrenic resin produced is not sufficient, the affinity is insufficient, and the surface appearance of the resulting thermoplastic resin composition is poor, resulting in delamination and the like. It is not preferred because it will occur. On the other hand, if the amount of grafting exceeds 5 parts by weight, the processability of the thermoplastic resin composition obtained will deteriorate, which is not preferable.

There is no limitation on the method for producing the acid-modified polyolefin, and a mixture obtained by mixing polyolefin, α, β-unsaturated carboxylic acid and a small amount of an organic peroxide using a Henschel mixer or the like can be uniaxially or biaxially mixed. It is supplied to an extruder and melt-kneaded at a temperature of 180 to 250 ° C., a polyolefin is dissolved in an appropriate solvent, and α, β-unsaturated carboxylic acid and an organic peroxide are added thereto to graft in a solution state. A method of reacting can be mentioned.

The epoxy group-containing olefin copolymer (C) used in the present invention is a copolymer composed of an unsaturated epoxy compound and an olefin, or these and another ethylenically unsaturated compound. The composition ratio of the epoxy group-containing olefin copolymer is not particularly limited, but the unsaturated epoxy compound is 0.05 to 95% by weight, and the olefin is 5 to 9%.
It is preferably 9.5% by weight and 0 to 50% by weight of another ethylenically unsaturated compound.

The unsaturated epoxy compound is a compound having an unsaturated group and an epoxy group, which can be copolymerized with an olefin and an ethylenically unsaturated compound, in the molecule. For example, unsaturated glycidyl esters, unsaturated glycidyl ethers, epoxy alkenes, unsaturated epoxy compounds such as P-glycidyl styrenes. Specifically, glycidyl acrylate, glycidyl methacrylate, itaconic acid glycidyl esters, butenecarboxylic acid 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-3-methylpentene,
5,6-epoxy-1-hexene, vinylcyclohexene monoxide, P-glycidyl styrene and the like can be mentioned, and one kind or two or more kinds can be used. Glycidyl acrylate or glycidyl methacrylate is particularly preferable.

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. As other ethylenically unsaturated compounds,
Examples thereof include vinyl esters containing C _{2 to} C ₆ in the saturated carboxylic acid component, acrylic acid and methacrylic acid esters and maleic acid esters containing C _{1 to} C ₈ in the saturated alcohol component, vinyl halides and the like.

Epoxy group-containing olefin copolymer (C)
Is a copolymer of an unsaturated epoxy compound and an olefin and optionally other ethylenically unsaturated compound, or is unsaturated in the presence of an olefin polymer or a copolymer of an olefin and another ethylenically unsaturated compound. It is produced by graft-copolymerizing an epoxy compound. Particularly preferred is a copolymer of an unsaturated epoxy compound, an olefin and, if necessary, another ethylenically unsaturated compound.

Epoxy group-containing olefin copolymer (C)
Preferred examples of ethylene-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, ethylene-methyl methacrylate-glycidyl methacrylate copolymer, and polyethylene, polypropylene, poly-1-butene, poly-4
-Methyl-pentene-1, ethylene-propylene copolymers, ethylene-propylene-diene copolymers and the like copolymers obtained by graft reaction of glycidyl methacrylate in the presence of olefin polymers.

Epoxy group-containing olefin copolymer (C)
As a method for producing the above, a known method for producing an olefin polymer is used.

Epoxy group-containing olefin copolymer (C)
The compounding amount of 0.1 to 2 per 100 parts by weight of the total of the acid-modified styrene resin (A) and the acid-modified polyolefin (B).
0 parts by weight. If the blending amount of the epoxy group-containing olefin copolymer is less than 0.1 parts by weight, the reaction between the acid-modified styrene resin and the acid-modified polyolefin is not sufficient, and the surface appearance of the thermoplastic resin composition obtained due to lack of affinity is Bad,
It is not preferable because it causes delamination. On the other hand, if the blending amount exceeds 20 parts by weight, the reaction between the acid-modified styrene-based resin and the acid-modified polyolefin becomes excessive, resulting in poor processability of the thermoplastic resin composition.

Acid-modified styrenic resin (A) and acid-modified polyolefin (B) in the thermoplastic resin composition of the present invention
The mixing ratio of the acid-modified styrenic resin (A) is 20 to 80 parts by weight and the acid-modified polyolefin (B) is 80 to 20 parts by weight per 100 parts by weight in total. If the acid-modified styrene-based resin (A) is less than 20 parts by weight, the workability is poor, and 8
If it exceeds 0 parts by weight, the chemical resistance is insufficient. Preferably,
The acid-modified styrene resin (A) is 30 to 70 parts by weight, and the acid-modified polyolefin (B) is 70 to 30 parts by weight.

The acid-modified styrene resin (A), the acid-modified polyolefin (B) and the epoxy group-containing olefin copolymer (C) are mixed in a Banbury mixer, a roll, and 1
It can be carried out in a known mixing device such as a twin-screw or twin-screw extruder. In addition, the mixing order is not limited at all, and a method of collectively mixing the three components, a method of previously mixing the specific two components, and a method of mixing the remaining one component can be adopted.

When mixing, known additives such as antioxidants (phenolic antioxidants, amine antioxidants, sulfur antioxidants, phosphorus antioxidants, etc. are exemplified. ], An ultraviolet absorber [pt-butylphenyl salicylate, 2,2'-dihydroxy-4-methoxybenzophenone, 2- (2'-hydroxy-4'-n-octoxyphenyl) benzotriazole and the like are exemplified. . ], Lubricants [paraffin wax, stearic acid, hydrogenated oil, stearamide, methylenebis stearamide,
Examples thereof include ethylene bis stearamide, n-butyl stearate, ketone wax, octyl alcohol, lauryl alcohol, hydroxystearic acid triglyceride and the like. ], A colorant [eg titanium oxide, carbon black], a filler [eg calcium carbonate, clay,
Examples thereof include silica, glass fiber, glass sphere, carbon fiber and the like. ], Flame retardant [for example, tetrabromobisphenol A, hexabumcyclododecane, bis (tribromophenoxy) ethane, polybromodiphenyl oxide,
Examples thereof include poly-dibromophenylene oxide, tetrabromobisphenol A carbonate oligomer, tetrabromobisphenol A epoxy oligomer, brominated phenoxy, brominated polystyrene, ethylenebistetrabromophthalimide, antimony oxide and the like. ] Etc. can be added as needed.

Further, in the present invention, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-α-methylstyrene copolymer, ABS resin, M
Styrenic resin containing no epoxy group such as BS resin,
High density polyethylene, medium density polyethylene, low density polyethylene, polypropylene, propylene and other α-
It is also possible to blend other thermoplastic resins such as polyolefins which are not acid-modified such as copolymers with olefins, polycarbonates, polyamides, polyesters, polyphenylene oxide, polyvinyl chloride, polymethylmethacrylate.

Next, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The number of parts and% are shown by weight. The various resins used in the examples and comparative examples are as follows.

A-1: Polybutadiene latex (particle size 0.35 μm, gel 80%) 50 parts (solid content), styrene 32 parts, acrylonitrile 13 parts and methacrylic acid 5
Parts were polymerized by a known emulsion polymerization method. Then, the obtained polymer latex is salted out, dehydrated and dried to give A-1.
I got

A-2: 64 parts of styrene, 26 parts of acrylonitrile and 10 parts of methacrylic acid were polymerized by a known emulsion polymerization method. Then, the obtained polymer latex was salted out, dehydrated and dried to obtain A-2.

A-3-4 and X-1-2: Styrene (STY), acrylonitrile (ACN) as follows:
Polymerization was carried out in the same manner as in A-2 except that the number of parts of methacrylic acid (MAA) and methacrylic acid were changed to acrylic acid (AA) to obtain A-3 to 4 and X-1 to 2.

A-3: STY 65 parts ACN 30 parts MAA 5 parts A-4: STY 70 parts ACN 20 AA 10 X-1: STY 73 parts ACN 27 MAA 0.05 X-2: STY 50 ACN 20 AA 30

B-1: 100 parts of polypropylene (trade name Noblene AH561 manufactured by Sumitomo Chemical Co., Ltd.), 1 part of maleic anhydride and 0.2 part of dicumyl peroxide were kneaded (220 ° C.) in an extruder with a vent, and then acidified. A modified polyolefin B (maleic anhydride content 0.2%) was obtained. B-2: Maleic anhydride in B-1 was changed to 5 parts to obtain acid-modified polyolefin B-2 (maleic anhydride content 1.1%).

Y-1: Maleic anhydride in B-1 was changed to 0.1 part to obtain acid-modified polyolefin Y-1 (maleic anhydride content 0.005%). Y-2: Maleic anhydride in B-1 was changed to 15 parts to obtain acid-modified polyolefin Y-2 (maleic anhydride content 6%).

C-1: 90% ethylene, 10% glycidyl methacrylate according to the polymerization conditions of high-pressure polyethylene using an autoclave type polyethylene manufacturing apparatus
The copolymer C-1 of was obtained. C-2: A copolymer C-2 having 90% ethylene, 7% glycidyl methacrylate and 3% vinyl acetate was obtained by the same method as C-1.

Examples 1 to 8 and Comparative Examples 1 to 7 The above acid-modified (unmodified) styrene resin, acid-modified polyolefin and epoxy group-containing olefin copolymer were blended in a Henschel mixer, and then uniaxially extruded. Melt kneading (220 ° C.) with a machine to obtain pellets of various thermoplastic resin compositions. The composition is shown in Tables 1-2. Next, using the obtained pellets, test pieces necessary for the following tests were prepared by a 3.5 ounce injection molding machine (nozzle temperature set to 220 ° C.). Various physical properties of each test piece were measured according to the methods described below. The results are shown in Tables 3-4.

Surface layer peeling resistance: The surface layer peeling from the gate portion of a flat plate molded product (100 mm × 150 mm) having a thickness of 2.5 mm was evaluated. The evaluation was made by a visual 3-point method, with the highest being 3 points and the lowest being 1 point. That is, the larger the number, the better the resistance to peeling of the surface layer. Impact resistance: Evaluated by an Izod impact test based on the ASTM D-256 standard. Unit: Kg · cm / c
m. Chemical resistance: Square plate injection-molded (50 mm x 70 m
m × 3 mm) was immersed in gasoline or dioctyl phthalate at 23 ° C. for 24 hours, and the surface of the square plate was visually observed to determine whether there was any change. There was a change, x, and there was no change, O. Workability: Melt index (200 ° C., 10 kg) was measured based on ASTM D-1238. Unit: g / 10 minutes. Color tone: The yellow index of the test piece was measured based on ASTM D-1925.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

[Table 3]

[0039]

[Table 4]

[0040]

EFFECT OF THE INVENTION The thermoplastic resin composition of the present invention does not cause peeling of the surface layer and has excellent chemical resistance, as compared with conventional compositions.
In addition, it has an excellent impact resistance-processability balance.
Therefore, it is possible to provide a material excellent in chemical resistance, surface appearance, and physical property balance for applications requiring chemical resistance such as vehicle parts and light electric parts.

Claims (1)

[Claims] 1. A) 20 to 94.9% by weight of an aromatic vinyl monomer, 5 to 60% by weight of a vinyl cyanide monomer and α in the presence or absence of (A) a rubbery polymer. 0.01 to 20 parts by weight of an acid-modified styrene resin obtained by polymerizing 0.1 to 20% by weight of a β-unsaturated carboxylic acid monomer and 100 parts by weight of a polyolefin (B).
20 to 80 parts by weight of an acid-modified polyolefin obtained by graft-reacting 5 parts by weight of an α, β-unsaturated carboxylic acid-based monomer [where (A) + (B) = 100 parts by weight] with (C). 0.1 to 2 epoxy group-containing olefin copolymer
A thermoplastic resin composition comprising 0 part by weight.