JPH07109398A - Chemical-resistant resin composition - Google Patents

Abstract

PURPOSE:To provide the resin composition having effects excellent in chemical resistance, high in compatibility, and good in mechanical strength. CONSTITUTION:A resin composition comprises 100 pts.wt. of a resin composition and (C) 0.1-20 pts.wt. of a graft copolymer produced by substantially grafting (C'') a copolymer comprising a vinyl cyanide compound and an aromatic vinyl compound and/or a (meth)acrylate ester compound to (C') a copolymer containing ethylene as constituting units. The resin composition comprises (A) 5-80 pts.wt. of a graft copolymer produced by grafting a vinyl cyanide compound and an aromatic vinyl compound to a rubbery polymer, the amounts of the rubbery polymer and the graft component being 30-95wt.% and 5-70wt.%, respectively, and the amount of the vinyl cyanide compound being 0.2-0.8wt.% per the total weight of the vinyl cyanide component and the aromatic vinyl compound, and (B) 20-95 pts.wt. of a vinylic copolymer comprising 20-80wt.% of a vinyl cyanide compound and 20-80wt.% of an aromatic vinyl compound and/or a (meth)acrylate ester compound.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a styrene resin composition having excellent chemical resistance.

[0002]

2. Description of the Related Art As a method for improving the chemical resistance of a styrene resin, as disclosed in Japanese Patent Application Laid-Open No. 2-284906, inclusion of a component excellent in chemical resistance in the resin, for example, acrylonitrile. The method of increasing the amount is common. However, if the acrylonitrile content in the resin is greatly increased, there are problems in production such as a decrease in color tone and an increase in gelation reaction, and a molded product that is satisfactory in these respects cannot be obtained. On the other hand, as another method for obtaining a high degree of chemical resistance, a method in which a crystalline polymer such as polyamide is blended with a styrene resin, or JP-B-60-36 is used.
As disclosed in JP-A No. 178 and JP-A-3-292112, a method of blending an ethylene-vinyl acetate copolymer with a styrene resin is known, but these resins are inherently poor in compatibility. Therefore, there are practical problems such as deterioration of mechanical properties of the resin and peeling of the molded piece.

[0003]

DISCLOSURE OF THE INVENTION The present invention is to provide a resin composition having excellent compatibility and excellent chemical resistance while maintaining mechanical properties at a high level.

[0004]

That is, the present invention is as follows.
(A) A graft copolymer obtained by grafting a vinyl cyanide compound and an aromatic vinyl compound onto a rubber polymer, wherein the rubber polymer is 30 to 95% by weight and the graft component is 5 to 70% by weight. And the vinyl cyanide compound is a graft copolymer 5 to 80 in which the total weight of the vinyl cyanide compound and the aromatic vinyl compound is 0.2 to 0.8.
Parts by weight, (B) vinyl cyanide compound 20 to 80% by weight
And (C) ethylene as a constitutional unit in 100 parts by weight of a resin composition consisting of 20 to 95 parts by weight of a vinyl copolymer consisting of 20 to 80% by weight of an aromatic vinyl compound and / or a (meth) acrylic acid ester compound. Graft copolymer 0.1 obtained by substantially grafting a copolymer (C ″) comprising a vinyl cyanide compound and an aromatic vinyl compound and / or a (meth) acrylic acid ester compound onto the copolymer (C ′) The resin composition is characterized by comprising 20 to 20 parts by weight, and the present invention will be described in detail below.

The vinyl cyanide compound used in the present invention includes acrylonitrile and methacrylonitrile. Especially preferred is acrylonitrile. Examples of the aromatic vinyl compound include styrene, α-methylstyrene, and paramethylstyrene. The rubbery polymer has a glass transition temperature of 0 ° C or lower, preferably -20.
It should be below ℃. Specifically, polybutadiene, styrene-butadiene copolymer rubber, diene rubber such as acrylonitrile-butadiene copolymer rubber, acrylic rubber such as polybutyl acrylate, polyisoprene, polychloroprene, ethylene-propylene rubber, ethylene-propylene- Block copolymers such as diene terpolymer rubbers, styrene-butadiene block copolymer rubbers, styrene-isoprene block copolymer rubbers and hydrogenated products thereof can be used.

[0006] Preferably, polybutadiene, styrene-
Examples thereof include butadiene copolymer rubber and acrylonitrile-butadiene copolymer rubber. The proportion of the rubber-like polymer in the graft copolymer (A) is used in the range of 30 to 95% by weight, but preferably 50 to 90% by weight in terms of the balance of impact resistance and processing fluidity. It is a range.

The proportion of the graft component should be 5 to 70% by weight. If it is less than 5% by weight, the compatibility with the matrix resin is lowered, the rubbery polymer is aggregated, and the surface gloss of the resin is lowered, which is not preferable. On the other hand, if it exceeds 70% by weight, the impact resistance of the resin decreases, which is not preferable. A more preferable range is 10 to 50% by weight.

The proportion of the rubbery polymer and the graft component in the graft copolymer is specifically measured by dissolving the polymer produced by the polymerization in acetone and separating and removing the insoluble matter by a centrifuge. You can
The component that dissolves in acetone is the component that did not undergo graft reaction in the copolymerized polymer (non-graft polymer), and the value obtained by subtracting the amount of rubber polymer from the acetone insoluble content is defined as the value of the graft component. To be done.

The vinyl cyanide compound as a copolymerization component in the graft copolymer (A) must be 0.2 to 0.8 of the total weight of the vinyl cyanide compound and the aromatic vinyl compound. If it is less than 0.2, sufficient chemical resistance cannot be obtained. On the other hand, when it exceeds 0.8, the cyclization reaction and the crosslinking reaction of the vinyl cyanide compounds proceed unfavorably during high temperature processing. More preferably 0.35 to 0.
The range is 6. More preferably, it is 0.4 to 0.5.

Examples of the (meth) acrylic acid ester compound in the vinyl copolymer (B) include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate and butyl methacrylate. Particularly preferred is butyl acrylate. The proportion of the vinyl cyanide compound in the vinyl copolymer (B) needs to be in the range of 20 to 80% by weight. If it is less than 35% by weight, sufficient chemical resistance cannot be obtained. If the amount exceeds 80% by weight, the cyclization reaction and the crosslinking reaction of the vinyl cyanide compounds proceed during high temperature processing, which is not preferable. More preferably 35-
It is in the range of 60% by weight. More preferably 40 to 50
% By weight.

The preferred molecular weight of the vinyl copolymer (B) is in the range of 3 to 20 centipoise when the viscosity at 25 ° C. is measured at a polymer concentration of 10% by weight using a methyl ethyl ketone solvent. The copolymer (B) may contain a non-graft polymer component produced when the graft copolymer (A) is produced. However, the composition and content of the non-graft polymer component derived from this graft copolymer (A) are within the range of the above-mentioned copolymer (B) as a whole even when it is contained in the copolymer (B). It is necessary to be inside.

The copolymer of the copolymer (C ') containing ethylene as a constituent unit in the graft copolymer (C) is specifically vinyl acetate, methyl acrylate, ethyl acrylate or the like ( It is selected from among (meth) acrylic acid esters. Preferred are vinyl acetate and ethyl acrylate. From the viewpoint of compatibility and chemical resistance, the ratio of ethylene to the copolymer is from 5 wt% as a copolymer.
A range of 50 wt% is preferable.

The copolymer composition of the copolymer (C ") in the graft copolymer (C) is determined according to the composition of the graft copolymer (A) and the vinyl copolymer (B) to be blended. The composition of the copolymer (E) is preferably selected from the viewpoint that it has a high compatibility with the graft copolymer (A) and the vinyl copolymer (B). The molecular weight is the graft copolymer (A)
When blended with the vinyl copolymer (B), the mechanical strength thereof is not impaired.

The amount of the copolymer (C ″) in the graft copolymer (C) is in the range of 5 to 400 parts by weight with respect to 100 parts by weight of the copolymer (C ′). If so, the function as a compatibilizer becomes insufficient.
When the amount is more than parts by weight, the amount of the copolymer (D) is relatively decreased, so that the effect of improving chemical resistance is small.
It is preferably 20 to 150 parts by weight.

The blending ratio of the polymers (A), (B) and (C) is 0.1 to 20 parts by weight of (C) when the total amount of (A) and (B) is 100 parts by weight. Must be within the range. First, the compounding ratio of (A) and (B) is determined according to the required resin characteristics.
When (B) is 100 parts by weight, it is necessary that (A) is in the range of 5 to 80 parts by weight in order to obtain a balance of mechanical properties.

Next, when the amount of (C) added is less than 0.1 parts by weight relative to 100 parts by weight of (A) + (B), the effect of improving chemical resistance is not sufficient, and 20 parts by weight is added. If it exceeds the range, the compatibility of the resin is lowered and peeling occurs in the molded piece, which is not preferable. A more preferable range is
It is 0.5 to 10 parts by weight. The method for producing the resin composition in the present invention is not particularly limited, and a usual method,
For example, it can be manufactured by melt blending by extruder kneading. At this time, if necessary, a usual antistatic agent, antioxidant, ultraviolet absorber, flame retardant, pigment, dye,
It is possible to add additives such as lubricants.

The chemical resistance of the resin composition of the present invention is specifically applied to the following substances, but is not limited thereto. For example, HCFC-123, HCFC
-141b and other urethane foam freons, organic solvents such as esters, ketones and halogenated hydrocarbons, organic phosphorus insecticides such as Sumithion and Parathion, margarine, food materials such as vinegar (3% acetic acid), grease, Oils such as sewing machine oil, bactericidal agents such as cresol, alcohol-based household detergents and cleaners, hair styling agents, cosmetics and the like can be mentioned.

[0018]

[Example] A measuring method will be described. The Izod impact value was measured based on ASTM D256. Fluorocarbon resistance is based on compression molded and annealed test pieces (width 12.7m
(m × thickness 1.0 mm), the center is covered with gauze, the outside is covered with Saran wrap, and a load of 0.75% strain is applied to the test piece, and then Freon 141b is injected with a syringe to perform a creep test. Then, the time (seconds) from the injection to the break of the test piece was measured.

During the test, from time to time to prevent the gauze from drying out,
CFC 141b was injected. For the peelability, the presence or absence of peeling of the dumbbell fracture surface after the tensile test was visually determined. As for the anti-sumithione, a compression molded product having a thickness of 3 mm was cut into a width of 12.7 mm, annealed at 80 ° C. for 48 hours, and then attached to a bending foam. Then gauze is soaked with Sumithion and overlaid on the product. The value of the critical strain (%) in which a crack is generated by leaving it in a thermostatic chamber at 23 ° C and 50% humidity for 24 hours.
To measure. The larger this value, the better the chemical resistance.

Hereinafter, "part" means "part by weight".

[0021]

Examples 1 to 5 and Comparative Examples 1 to 3 [Method for producing graft copolymer] (Graft copolymer A-1) Polybutadiene rubber latex (weight average particle diameter 3000 angstrom) 40
To 100 parts, deionized water (100 parts) and potassium rosinate (1.5 parts) were added, the gas phase was replaced with nitrogen, and the temperature was raised to 70 ° C.

Then, 27 parts of acrylonitrile, 33 parts of styrene, 0.6 parts of tertiary decyl mercaptan.
Part, cumene hydroperoxide (0.1 part by weight), 50 parts of deionized water, 0.2 part of sodium formaldehyde sulfoxylate, 0.004 parts of ferrous sulfate.
Parts, ethylenediaminetetraacetic acid disodium salt 0.0
An aqueous solution prepared by dissolving 4 parts was added over 7 hours,
The reaction was completed at a polymerization temperature of 0 ° C.

The content of acrylonitrile units in the components excluding the rubber-like polymer determined by an infrared spectrophotometer is 4
It was 3% by weight. This graft copolymer latex is salted out and dehydrated and then dried to obtain powdered graft copolymer A.
-1 was obtained. The content of acetone insoluble in the graft copolymer A-1 was 58% by weight, and the content of acetone soluble in it was 42% by weight. When the composition of the acetone insoluble matter in the graft copolymer was measured by an infrared spectrophotometer, the content of the rubber polymer was 69% by weight, the content of the graft component was 31% by weight, and the ratio of the acrylonitrile unit was Was 0.43. This acetone insoluble matter is referred to as a graft copolymer I. (Graft copolymer A-2) Graft copolymer A-2 was prepared in exactly the same manner as graft copolymer A-1, except that 25 parts of acrylonitrile and 35 parts of styrene in the monomer mixture were used. Obtained. The content of acrylonitrile units in the components excluding the rubbery polymer determined by an infrared spectrophotometer was 40% by weight.

The content of acetone insoluble in the graft copolymer A-2 was 58% by weight, and the content of acetone soluble in it was 42% by weight. When the composition of the acetone insoluble matter in the graft copolymer was measured by an infrared spectrophotometer, the content of the rubber polymer was 69% by weight, the content of the graft component was 31% by weight, and the ratio of the acrylonitrile unit was Was 0.40. This acetone insoluble matter is referred to as a graft copolymer II. (Graft copolymer A-3) Graft copolymer A-3 was prepared in exactly the same manner as graft copolymer A-1, except that 17 parts of acrylonitrile and 43 parts of styrene in the monomer mixture were used. Obtained.

The content of acrylonitrile units in the components excluding the rubbery polymer determined by an infrared spectrophotometer is 2
It was 7% by weight. The content of acetone insoluble in the graft copolymer A-3 was 60% by weight, and the content of acetone soluble in it was 40% by weight. When the composition of the acetone insoluble matter in the graft copolymer was measured by an infrared spectrophotometer, the content of the rubbery polymer was 70% by weight, the content of the graft component was 30% by weight, and the proportion of the acrylonitrile unit was Was 0.27. This acetone insoluble matter is referred to as a graft copolymer III. (Copolymer B-1) An AS resin (acrylonitrile-styrene copolymer) having a solution viscosity of 6 centipoise and an acrylonitrile content of 40 parts in the resin. (Copolymer B-2) A terpolymer having a solution viscosity of 6 centipoise, an acrylonitrile content in the resin of 40 parts, butyl acrylate of 11 parts, and styrene of 49 parts. (Copolymer B-3) AS resin (acrylonitrile-styrene copolymer) having a solution viscosity of 5 centipoise and an acrylonitrile content in the resin of 27 parts. (Graft Copolymer C) As the graft copolymer C, MODIPER A series manufactured by NOF CORPORATION was used (Table 1).

The above resins were blended in the composition shown in Table 2 and kneaded and granulated by a twin-screw extruder having a cylinder temperature of 240 ° C. Thereafter, a test piece for measuring physical properties was obtained by injection molding at a molding temperature of 240 ° C. Table 3 shows the measurement results of these physical properties.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

[0030]

Industrial Applicability The resin composition of the present invention has excellent compatibility and excellent chemical resistance while maintaining high mechanical strength.

Claims (1)

[Claims] 1. A graft copolymer obtained by grafting (A) a vinyl cyanide compound and an aromatic vinyl compound onto a rubber polymer, wherein the rubber polymer is 30 to 95% by weight.
The graft component is 5 to 70% by weight, and the vinyl cyanide compound is 0.2 to 0.8 of the total weight of the vinyl cyanide compound and the aromatic vinyl compound. Part, (B) vinyl cyanide compound 2
100 parts by weight of a resin composition comprising 20 to 95 parts by weight of a vinyl copolymer comprising 0 to 80% by weight of an aromatic vinyl compound and / or 20 to 80% by weight of a (meth) acrylic acid ester compound, and (C) ethylene. A graft copolymer obtained by substantially grafting a copolymer (C ′) containing a vinyl cyanide compound, an aromatic vinyl compound and / or a (meth) acrylic acid ester compound, onto the copolymer (C ′) containing A resin composition comprising 0.1 to 20 parts by weight of a polymer.