JP2928961B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermoplastic resin composition having excellent chemical resistance.

[0002]

2. Description of the Related Art ABS resin (acrylonitrile-diene rubber-styrene polymer), AES resin (acrylonitrile-ethylene propylene rubber-styrene polymer), ACS resin (acrylonitrile-chlorinated polyethylene-styrene polymer) ) And AAS resin (acrylonitrile-acrylic rubber-styrene polymer) are used in the fields of vehicles, light electric appliances, sundries, etc. due to their excellent balance of impact resistance and workability. Have been.

[0003] However, these rubber-reinforced styrene resins are inferior in chemical resistance to other engineering plastics, and have a problem that cracks are easily generated when they come into contact with gasoline, brake fields, grease and the like.

It has been known that the chemical resistance is improved by increasing the amount of vinyl cyanide (acrylonitrile) in a rubber-reinforced styrenic resin, but the impact resistance is reduced with an increase in acrylonitrile. At the same time, there is a limit in improving the chemical resistance due to the initial coloring.

Further, the present applicant has already found improvement in chemical resistance by blending a terpolymer comprising olefin-unsaturated dicarboxylic anhydride-unsaturated carboxylic acid alkyl ester. With the diversification and functionalization of, the development of a composition having even more excellent chemical resistance has been desired.

On the other hand, Japanese Patent Application Laid-Open Nos. 59-89346 and
Japanese Patent Application No. 0-18536 discloses a resin composition having an excellent matting effect obtained by blending an epoxy resin containing an epoxy group with an ABS resin or an AES resin. No. 245662 describes a resin composition having improved color developability obtained by blending polymethyl methacrylate or methyl methacrylate-styrene-acrylonitrile terpolymer to AES resin, respectively.
There is no description on improvement of chemical resistance. Further, JP-A-63-
No. 245461 describes a resin composition obtained by blending an ABS resin with a methyl methacrylate-styrene-acrylonitrile terpolymer to improve color development and chemical resistance, but the chemical resistance is not yet described. It was not enough.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to obtain a resin composition having excellent chemical resistance. As a result, the rubber-reinforced graft copolymer has a specific unsaturated carboxylic acid alkyl ester-based resin. It has been found that by blending a specific amount of the polymer and the epoxy group-containing olefin copolymer, a resin composition having excellent chemical resistance can be obtained without sacrificing impact resistance, and the present invention has been achieved.

That is, the present invention relates to a graft copolymer obtained by polymerizing a rubbery polymer with two or more compounds selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound and an unsaturated carboxylic acid alkyl ester compound. 10 to 70% by weight of the polymer (A) and 50 to 100% by weight of the unsaturated carboxylic acid alkyl ester compound (however, 50 % by weight)
%) And 0 to 50% by weight of the aromatic vinyl compound and / or vinyl cyanide compound (excluding 50% by weight).
A) a composition 100 comprising 90 to 30% by weight of an unsaturated carboxylic acid alkyl ester polymer (B) obtained by polymerizing
A thermoplastic resin characterized by being mixed with 0.1 to 40 parts by weight of an epoxy group-containing olefin copolymer (C) comprising an unsaturated epoxy compound and an olefin or an ethylenically unsaturated compound and an unsaturated epoxy compound per part by weight. It provides a composition.

Hereinafter, the present invention will be described in detail.

-Graft Copolymer (A)-Examples of the rubbery polymer in the graft copolymer (A) include polybutadiene, butadiene-styrene copolymer,
Butadiene-based rubber such as butadiene-acrylonitrile copolymer, ethylene-propylene copolymer, dicyclopentadiene, ethylidene norbornene, 1,4-hexadiene, 1,4-cycloheptadiene, and 1,5-cyclooctadiene. Ethylene-copolymerized conjugated diene
Ethylene-propylene rubber such as propylene-non-conjugated diene copolymer, in the presence or absence of a crosslinking agent, an acrylate having 1 to 16 carbon atoms in the alkyl group, for example, methyl acrylate, ethyl acrylate, butyl acrylate, 1 such as 2-ethylhexyl acrylate
Acrylic acid ester obtained by polymerizing or copolymerizing one or more kinds or other kinds of other monomers which can be further copolymerized as required, for example, one or more kinds of styrene, acrylonitrile, methyl methacrylate and the like Rubber and the like. One type or two or more types can be used. These rubbery polymers can be produced by emulsion polymerization, solution polymerization, bulk polymerization, suspension polymerization and the like.

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

Examples of the vinyl cyanide compound include acrylonitrile, methacrylonitrile and the like, and one or more kinds can be used. Acrylonitrile is particularly preferred.

As the unsaturated carboxylic acid alkyl ester compound, methyl acrylate, ethyl acrylate,
Examples thereof include butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, and 2-ethylhexyl methacrylate, and one or more kinds can be used. Particularly, methyl methacrylate is preferable.

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

The composition ratio of the rubber to be subjected to the graft polymerization and the compound (total) is not particularly limited.
% By weight and 90 to 20% by weight of a compound (total). The composition ratio of each compound is not particularly limited, but 50 to 90% by weight of an aromatic vinyl compound and a vinyl cyanide compound and / or The unsaturated carboxylic acid alkyl ester compound is preferably 10 to 50% by weight.

Further, from the viewpoint of chemical resistance, the graft copolymer (A) is obtained by mixing a graft copolymer (A-1) obtained by polymerizing a compound with an acrylate rubber and a butadiene rubber or ethylene-based rubber. It is preferably a mixture with a graft copolymer (A-2) obtained by polymerizing a compound on a propylene rubber. These graft copolymers (A-
There are no particular restrictions on the composition ratio of 1) and (A-2), but (A-1) 10 to 90% by weight and (A-2) 90
It is preferably from 10 to 10% by weight.

The graft copolymer (A-2) is selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound and an unsaturated carboxylic acid alkyl ester compound in a butadiene rubber or an ethylene-propylene rubber. Graft copolymer (A-2-1) obtained by polymerizing two or more compounds and graft copolymer (A-2-2) obtained by polymerizing two or more compounds selected from the above compound group
Or a mixture consisting of

The composition ratio of the graft copolymer (A-2-1) and the copolymer (A-2-2) is not particularly limited, but is not limited to 10 to 10. It is preferred that the copolymer (A-2-2) is composed of 100% by weight and 0 to 90% by weight.

The composition ratio of each compound constituting the copolymer (A-2-2) is not particularly limited, but is 50 to 90% by weight of an aromatic vinyl compound and 10 to 10% by weight of a vinyl cyanide compound.
Preferably, it is 50% by weight and 0 to 40% by weight of the unsaturated carboxylic acid alkyl ester compound.

-Unsaturated carboxylic acid alkyl ester polymer (B)-The unsaturated carboxylic acid alkyl ester polymer in the present invention refers to an unsaturated carboxylic acid alkyl ester compound in an amount of 50 to 100% by weight (50% by weight, Excluding
G) and an aromatic vinyl compound and / or a vinyl cyanide compound in an amount of 0 to 50% by weight (excluding 50% by weight).
It is a polymer obtained by polymerization.

When the content of the unsaturated carboxylic acid alkyl ester compound is less than 50% by weight, the chemical resistance is poor, which is not preferable. From the viewpoint of the balance between physical properties of chemical resistance and impact resistance, the content may be 50 to 95% by weight of an unsaturated carboxylic acid alkyl ester compound, 5 to 50% by weight of an aromatic vinyl compound, and 0 to 45% by weight of a vinyl cyanide compound. It is particularly preferred that the content is 50 to 90% by weight of an unsaturated carboxylic acid alkyl ester compound, 5 to 45% by weight of an aromatic vinyl compound and 5 to 45% by weight of a vinyl cyanide compound.

The unsaturated carboxylic acid alkyl ester compound, the aromatic vinyl compound and the vinyl cyanide compound constituting the unsaturated carboxylic acid alkyl ester polymer (B) are the same as those of the graft copolymer (A). The same ones as described can be used.

As the method for producing the unsaturated carboxylic acid alkyl ester-based polymer (B), known emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, or a combination thereof can be employed.

-Epoxy Group-Containing Olefin Copolymer (C)-The epoxy group-containing olefin copolymer (C) used in the present invention comprises an unsaturated epoxy compound and an olefin or these and an ethylenically unsaturated compound. It is a copolymer. Although there is no particular limitation on the composition ratio of the epoxy group-containing olefin copolymer, the unsaturated epoxy compound 0.05 to
Preferably it is 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 glycidyl esters, unsaturated glycidyl ethers, epoxy alkenes, P-
It is an unsaturated epoxy compound such as glycidyl styrene.

Specifically, glycidyl acrylate, glycidyl methacrylate, glycidyl itaconate, butene carboxylate, 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-
Examples thereof include methylpentene, 5,6-epoxy-1-hexene, vinylcyclohexene monoxide, and P-glycidylstyrene, and one or more kinds thereof can be used. Particularly, glycidyl acrylate or glycidyl methacrylate is preferred.

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

Examples of the ethylenically unsaturated compound include vinyl esters containing C ₂ -C ₆ as a saturated carboxylic acid component, acrylic and methacrylic esters and maleic acid esters containing C ₁ -C ₈ as a saturated alcohol component. , Vinyl halides and the like.

These ethylenically unsaturated compounds are copolymerized in an amount of 50% by weight or less, especially 0.1 to 45% by weight, based on the total amount of the compounds when the unsaturated epoxy compound and the olefin are copolymerized.

Epoxy-containing olefin copolymer (C)
Can be obtained by copolymerizing an unsaturated epoxy compound with an olefin and, if necessary, an ethylenically unsaturated compound, or grafting an unsaturated epoxy compound in the presence of an olefin polymer or a copolymer of an olefin and an ethylenically unsaturated compound. It is produced by copolymerization.

Epoxy-containing olefin copolymer (C)
Preferred examples of the 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, an ethylene-propylene copolymer, an ethylene-propylene-diene copolymer, and other copolymers obtained by grafting glycidyl methacrylate in the presence of an olefin polymer.

Epoxy-containing olefin copolymer (C)
As a method for producing, an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, a solution polymerization method, or a polymerization method combining these is used.

The thermoplastic resin composition of the present invention comprises 100% by weight of a composition comprising 10 to 70% by weight of the above graft copolymer (A) and 90 to 30% by weight of the unsaturated alkyl carboxylate polymer (B). Parts by weight of the epoxy group-containing olefin copolymer (C) in an amount of 0.1 to 40 parts by weight.

If the graft copolymer (A) is less than 10% by weight (polymer (B) exceeds 90% by weight), the impact resistance is poor, and if it exceeds 70% by weight (polymer (B) is 30%).
% By weight) is not preferable because of poor chemical resistance. Preferably, the graft copolymer (A) is 20 to 70% by weight and the unsaturated carboxylic acid alkyl ester-based polymer is 80 to 30% by weight.

Epoxy-containing olefin copolymer (C)
If it is less than 0.1 part by weight, the chemical resistance is inferior. If it exceeds 40 parts by weight, delamination tends to occur, which is not preferable. Preferably it is 0.5 to 20 parts by weight.

The method of mixing the graft copolymer (A), the unsaturated carboxylic acid alkyl ester polymer (B) and the epoxy group-containing olefin copolymer (C) is not particularly limited, and may be in the form of a latex or a powder. , Beads, pellets and the like can be mixed.

As the melt kneading method, known methods such as a Banbury mixer, a roll, and an extruder can be adopted.

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, if necessary. Also, including olefin-unsaturated dicarboxylic anhydride-unsaturated carboxylic acid alkyl ester terpolymer,
Thermoplastic resins such as polyacetal, polycarbonate, polybutylene terephthalate, polyphenylene oxide, polymethyl methacrylate, and polyvinyl chloride can be appropriately blended.

Next, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these. All parts and percentages are shown on a weight basis.

Production of Graft Copolymer (A) A-1: 15 parts of acrylonitrile and 35 parts of styrene by an emulsion polymerization method in the presence of 50 parts (solid content) of a crosslinked polybutyl acrylate latex having an average particle diameter of 0.3 μm. Was copolymerized to produce an AAS graft copolymer latex (graft ratio: 50%, free acrylonitrile-styrene copolymer intrinsic viscosity: 0.36).

A-2-1-1: 15 parts of acrylonitrile and 35 parts of styrene were copolymerized by emulsion polymerization in the presence of 50 parts (solid content) of polybutadiene latex having an average particle diameter of 0.45 μm and a gel content of 83%. Thus, an ABS graft copolymer latex (graft ratio 73%, free acrylonitrile-styrene copolymer intrinsic viscosity 0.51) was produced. The intrinsic viscosity was measured in dimethylformamide at 30 ° C. (Unit 100ml / g)

A-2-1-2: Ethylene-propylene-ethylidene norbornene copolymer (EPDM, iodine value 21,
Mooney viscosity 75, propylene content 50%) 40 parts,
An AES graft copolymer consisting of 20 parts of acrylonitrile and 40 parts of styrene (graft ratio: 52%, intrinsic viscosity of free acrylonitrile-styrene copolymer: 0.61) was produced by a solution polymerization method.

A-2-2: An acrylonitrile-styrene copolymer comprising 30 parts by weight of acrylonitrile and 70 parts by weight of styrene was produced by a known emulsion polymerization method.

The graft copolymers A-1, A-2-1-1 and A-2-2 were each composed of 1 part of Sumilizer NW and 100 parts of trinolylphenyl phosphite 2 as antioxidant per 100 parts of solid content of latex. After the addition of part, salting out was performed using magnesium sulfate, and separation and recovery were performed. The graft copolymer A-2-1-2 was separated and recovered after precipitation in methanol.

-Unsaturated carboxylic acid alkyl ester-based polymer (B)-0.4 parts by weight of t-dodecyl mercaptan (molecular weight modifier) and benzoyl peroxide (initiator) are added to 100 parts by weight of a mixture having the composition shown in Table 1. After adding 0.3 parts by weight, polymerization was carried out at 80 ° C. for 8 hours based on a known suspension polymerization method using polyvinyl alcohol as a suspending agent. After dehydration,
Polymers B-1 and B-2 were obtained.

[0047]

[Table 1]

<PMMA> Polymethyl methacrylate “SUMIPEX MHO” manufactured by Sumitomo Chemical Co., Ltd.

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

C-1 Ethylene-glycidyl methacrylate-vinyl acetate copolymer (composition ratio 90-7-3) C-2 Ethylene-glycidyl methacrylate copolymer (composition ratio 90-10)

Reference Example 3-Production of olefin-unsaturated dicarboxylic anhydride-unsaturated carboxylic acid alkyl ester terpolymer (D)-Hydrocarbon distillation using a cylindrical autoclave equipped with a blade-type stirrer The monomer was polymerized at 185 ° C. and 160 atm in the presence of t-butyl 2-ethyl-per-hexanoate dissolved in water, ethylene 60%, maleic anhydride 4.5%
And a terpolymer of 35.5% ethyl acrylate.

The graft copolymer (A-
1, A-2-1 and 2), unsaturated carboxylic acid alkyl ester-based polymers (PMMA, B-1 and b-2) and epoxy group-containing olefin copolymers (C-1 and 2) and The starting copolymer was melt-kneaded with the composition shown in Table 2 to obtain a composition.

The physical properties of the obtained composition were measured by the following methods. Table 2 shows the results.

Izod Impact Strength ASTM D-256 1/4 "t Notched Izod Impact Strength 23 ° C.

Thermal deformation temperature ASTM D-648 1/4 "t 18.6Kg / cm ² Load No annealing

Chemical Resistance A test piece of 150 mm × 40 mm × 30 mmt is prepared by injection molding, fixed to a 1/4 elliptical jig shown in FIG. 1, and then coated with brake oil or gasoline. The distance (h) from the minimum deflection point to the crack occurrence point is measured, and the critical strain (%) is determined based on the following equation.

[0057]

(Equation 1) a; 16cm b; 7.5cm h; distance from minimum deflection point to crack generation point (c
m) t; Test piece thickness (0.3cm)

[0058]

[Table 2]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a 1/4 elliptical jig used for evaluating chemical resistance.

[Explanation of symbols]

 1 1/4 Elliptical jig 2 Minimum deflection point 3 Test piece a Length of jig bottom b Height of jig vertical

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 55:02 23:00) (C08L 33/06 51:04 23:00) (C08L 51/04 33:06 23:00) (C08L 55/02 33:06 23:00) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08L 51/00-55/02 C08L 23/00-23/24 C08L 33/06-33 /twenty two

Claims (2)

(57) [Claims] 1. A graft copolymer (A) obtained by polymerizing a rubbery polymer with two or more compounds selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound and an unsaturated carboxylic acid alkyl ester compound. ) 10-70% by weight and unsaturated carboxylic acid alkyl ester compound 50
To 100% by weight (excluding 50% by weight) and an aromatic vinyl compound and / or a vinyl cyanide compound from 0 to 5 %.
0% by weight (excluding 50% by weight) of an unsaturated carboxylic acid alkyl ester-based polymer (B) 90 to 90 %
0.1 to 40 parts by weight of an epoxy group-containing olefin copolymer (C) composed of an unsaturated epoxy compound and an olefin or an ethylenically unsaturated compound and 100 parts by weight of a 30% by weight composition. A thermoplastic resin composition comprising: 2. The graft copolymer (A) is obtained by adding two or more compounds selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound and an unsaturated carboxylic acid alkyl ester compound to an acrylate rubber. An aromatic vinyl compound to a graft copolymer (A-1) obtained by polymerization and a butadiene rubber or an ethylene-propylene rubber,
The thermoplastic according to claim 1, wherein the thermoplastic copolymer is a mixture with a graft copolymer (A-2) obtained by polymerizing two or more compounds selected from the group consisting of a vinyl cyanide compound and an unsaturated carboxylic acid alkyl ester compound. Resin composition.