JPH0781064B2 - Thermoplastic resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition having excellent heat resistance, impact resistance, chemical resistance, and surface condition of a molded article. More specifically, it relates to a thermoplastic resin composition comprising a resin containing an imidized copolymer and an acrylic acid ester polymer or a copolymer thereof mixed with the resin.

(Prior Art and Problems) Conventionally, a method for producing a polymer containing an unsaturated dicarboxylic acid imide derivative residue has been known. (USP 3,840,499, USP
3,998,907) Also, a composition in which an ABS resin is blended with these polymers to improve impact resistance is known. (USP 3,64
2,949, USP 3,652,726, JP-A-57-98,536, JP-A-57-
125,242) However, the disadvantage of these compositions is that they still do not have sufficient chemical resistance. It is also known that environmental stress crack resistance, that is, chemical resistance is improved by mixing a rubber-containing styrene resin with an acrylic ester polymer. (JP-A-58-179,257)
However, even the composition has the drawback that the heat resistance and the surface condition of the molded product are not sufficient.

(Means for Solving the Problems) As a result of intensive studies for solving the above drawbacks, the present invention shows that the imidized copolymer contains aromatic vinyl monomer residues and unsaturated dicarboxylic acid imides in a specific ratio. Only when it contains a derivative residue, a maleic anhydride residue and other vinyl monomer residue, heat resistance, impact resistance, chemical resistance and the surface of the molded product can be obtained only by mixing the acrylic ester polymer. It has succeeded in obtaining a composition in excellent condition.

That is, the present invention comprises (A) component: 0 to 30 parts by weight of a rubbery polymer, 40 to 80% by weight of an aromatic vinyl monomer residue, 20 to 60% by weight of an unsaturated dicarboxylic acid imide derivative residue, and maleic anhydride. Acid monomer residue 0
~ 15% by weight and other vinyl monomer residues 0-30% by weight
10 to 70% by weight of an imidized copolymer composed of 70 to 100 parts by weight of a monomer residue composed of (B) component: 5 to 80 parts by weight of a rubber-like polymer and an aromatic vinyl monomer residue. Consists of 20 to 95 parts by weight of monomer residues composed of 40 to 80% by weight of groups, 0 to 40% by weight of vinyl cyanide monomer residues and 0 to 40% by weight of other vinyl monomer residues Graft copolymer 10 to 80% by weight, (C) component: aromatic vinyl monomer residue 40 to 80% by weight, vinyl cyanide monomer residue 0 to 40% by weight and other vinyl monomers 0 to 70% by weight of a copolymer having a residue of 0 to 40% by weight, and (D) component: a homopolymer of an acrylic acid ester monomer having a glass transition temperature of 20 ° C. or less or a copolymer thereof 1 to 20. It is a thermoplastic resin composition characterized by comprising by weight%.

First, the imidized copolymer of the component A and the method for producing the same will be described.

As the method for producing the component (A) copolymer, an aromatic vinyl monomer, in the presence of a rubbery polymer, if necessary as the first production method,
A method of copolymerizing an unsaturated dicarboxylic acid imide derivative, a maleic anhydride monomer and a vinyl monomer mixture copolymerizable with these, and the second production method, if necessary, in the presence of a rubbery polymer, aromatic vinyl A monomer, an unsaturated dicarboxylic acid anhydride, or a copolymerized vinyl monomer mixture copolymerizable with them is reacted with ammonia and / or a primary amine to react all or one of the acid anhydride groups. There is a method of converting a part to an imide group, and an imidized copolymer can be obtained by any method.

As the aromatic vinyl monomer used in the first production method of the component (A) copolymer, styrene, α-methylstyrene,
It is a styrene monomer such as vinyltoluene, t-butylstyrene or chlorostyrene and a substituted monomer thereof, of which styrene is particularly preferable.

As the unsaturated dicarboxylic acid imide derivative, maleimide, N-methylmaleimide, N-butylmaleimide, N
-Cyclohexylmaleimide, N-arylmaleimide (for aryl groups such as phenyl, 4-diphenyl, 1-naphthyl, 2-chlorophenyl, 4-bromophenyl and other mono- and dihalophenyl isomers, 2,
4,6-tribromophenyl, methoxyphenyl and the like can be mentioned. ) And the like, and itaconic acid imide derivatives such as N-methylitaconic acid imide and N-phenylitaconic acid imide, and the like, and phenylmaleimide is particularly preferable.

The aromatic vinyl monomer used in the second production method is as described above, and as the unsaturated dicarboxylic acid anhydride,
There are anhydrides such as maleic acid, itaconic acid, citraconic acid and aconitic acid, and maleic anhydride is particularly preferable.

The maleic anhydride monomer residue may be 0% by weight,
Up to 15% by weight is acceptable. If it exceeds 15% by weight, thermal stability and hot water resistance are deteriorated, which is not preferable.

Vinyl monomers copolymerizable with these are those that constitute vinyl monomer residues other than aromatic vinyl monomer residues, unsaturated dicarboxylic acid imide derivative residues and maleic anhydride monomer residues. Thus, for example, vinyl cyanide monomers such as acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, methyl acrylate ester, ethyl acrylate ester acrylic acid ester monomers, methyl methacrylic acid ester, ethyl methacrylic acid ester. There are methacrylic acid ester monomers such as, acrylic acid, vinyl carboxylic acid monomers such as methacrylic acid, acrylic acid amides, methacrylic acid amides, and the like. Among these, acrylonitrile, methacrylic acid esters, acrylic acid, methacrylic acid, etc. Are preferred.

The rubber-like polymer used in the first or second production method is a butadiene polymer, a copolymer of a vinyl monomer copolymerizable with butadiene, an ethylene-propylene copolymer, an ethylene-propylene-diene copolymer. A polymer, a block copolymer of butadiene and aromatic vinyl, an acrylic acid ester polymer, and a copolymer of acrylic acid ester and a vinyl monomer copolymerizable therewith are used.

Examples of primary amines used in the imidization reaction in the second production include alkylamines such as methylamine, ethylamine, butylamine and cyclohexylamine, and aromatics such as chloro- or bromo-substituted alkylamines, aniline, tolylamine and naphthylamine. Group amines and halogen-substituted aromatic amines such as chloro- or bromo-substituted anilines. Of these, aniline is particularly preferred.

Component A copolymer is a rubber-like polymer 0 to 30 parts by weight, preferably 0 to 20 parts by weight and aromatic vinyl monomer residue 40 to 80% by weight, preferably 40 to 70% by weight, unsaturated dicarboxylic acid. Imido derivative residue 20 to 60% by weight, preferably 30 to 55% by weight,
An imidized copolymer consisting of 70 to 100 parts by weight of a monomer residue composed of 0 to 15% by weight of a maleic anhydride monomer residue and 0 to 30% by weight of a vinyl monomer residue other than these. is there.
When the amount of the rubber-like polymer exceeds 30 parts by weight, heat resistance, moldability and dimensional stability are impaired. When the amount of the aromatic vinyl monomer residue is less than 40% by weight, moldability and dimensional stability are impaired, and when it exceeds 80% by weight, heat resistance and chemical resistance are lowered, and the component (D) is The compatibility with the acrylic acid ester-based polymer is insufficient and the surface condition of the molded product deteriorates.
When the amount of vinyl monomer residues other than aromatic vinyl monomer residues, unsaturated dicarboxylic acid imide derivative residues and maleic anhydride monomer residues exceeds 30% by weight, dimensional stability and heat resistance Is damaged.

The copolymer rubber-like polymer which is the component (B) of the present invention is obtained by copolymerizing an aromatic vinyl monomer, a vinyl cyanide monomer and a vinyl monomer copolymerizable therewith, Examples of the polymer include a butadiene polymer, a copolymer of a vinyl monomer copolymerizable with butadiene, an ethylene-propylene copolymer, an ethylene-propylene-diethylene copolymer, and a block copolymer of butadiene and aromatic vinyl. A polymer, an acrylic acid ester polymer, a copolymer of an acrylic acid ester and a vinyl monomer copolymerizable therewith, and the like are used.

Examples of aromatic vinyl monomers include styrene monomers such as styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, chlorostyrene and substituted monomers thereof.

Examples of vinyl cyanide monomers include acrylonitrile, methacrylonitrile, and α-chloroacrylonitrile.

Vinyl monomers copolymerizable with these are those that constitute vinyl monomer residues other than aromatic vinyl monomer residues and vinyl cyanide monomer residues, and include, for example, methyl acrylate ester and ethyl acryl ester. Acrylic acid ester monomers such as acid esters, methacrylic acid ester monomers such as methyl methacrylic acid ester, ethyl methacrylic acid esters, etc. Vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid, acrylic acid amides, methacrylic acid amides, etc. There is.

The copolymer of the component (C) of the present invention is not an essential component,
From the viewpoint of moldability and economy, it is possible to contain up to 70% by weight.

Aromatic vinyl monomers, vinyl cyanide monomers and monomers copolymerizable therewith, which are used for preparing the component (C), are the same as those of the component (B), and should be used from among these. You can

The component (D) is a homopolymer of an acrylic acid ester monomer or a copolymer thereof, and preferably has a gel content of 20% by weight or less. As the acrylic acid ester monomer, methyl acrylic acid ester, ethyl acrylic acid ester, butyl acrylic acid ester, hexyl acrylic acid ester, cyclohexyl acrylic acid ester, octyl acrylic acid ester, octadecyl acrylic acid ester, hydroxyethyl acrylic acid ester, There are methoxyethyl acrylate, glycidyl acrylate, and phenyl acrylate. As a copolymerization monomer with these acrylic acid esters, there is a vinyl-based monomer, for example, styrene, α-methylstyrene,
Aromatic vinyl monomers such as vinyltoluene and t-butylstyrene, vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, amide monomers such as acrylamide and methacrylamide, acrylic acid, methacrylic acid and itaconic acid. , Unsaturated carboxylic acid monomers such as maleic anhydride, vinyl acetate, fatty acid vinyl ester monomers such as vinyl propionate, ethylene, propylene, 1-
There are olefin monomers such as butene and isobutylene, conjugated diene monomers such as butadiene and isoprene, and vinyl ether monomers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether and glycidyl vinyl ether.

The polymer of the component (D) of the present invention needs to have a glass transition temperature of 20 ° C. or lower. More preferably, it is 10 ° C or lower. If the glass transition temperature of the component (D) polymer exceeds 20 ° C., the chemical resistance of the composition of the present invention, that is, the resistance to environmental stress cracking is reduced, which is not preferable.

In the present invention, the component (A), the component (B), the component (C),
The proportions of the component (D) and the component (A) are 10 to 70% by weight, preferably 20 to 60% by weight, the component (B) is 10 to 80% by weight, preferably 20 to 60% by weight, and the component (C) is 0 to 0% by weight. The preferred range is 70% by weight, preferably 0 to 50% by weight, and the component (D) is 1 to 20% by weight, preferably 5 to 15% by weight. (A) component ratio is 10
If it is less than 70% by weight, the heat resistance improving effect is small.
If it exceeds, the impact strength of the resin composition will be insufficient. If the ratio of the component (B) is less than 10%, the impact strength is not sufficient,
If it exceeds 5% by weight, heat resistance and moldability will be poor.
The component (C) may be added if necessary, but if it exceeds 70% by weight, heat resistance and chemical resistance become insufficient. The proportion of the component (D) is 1 to 20% by weight, but if it is less than 1% by weight, the chemical resistance improving effect is not sufficient, and if it exceeds 20% by weight, the heat resistance is impaired.

The mixing method of the thermoplastic resin composition of the present invention is not particularly limited, and known means can be used. Examples of the means include a Banbury mixer, a tumbler mixer,
Examples include a mixing roll, a single-screw or twin-screw extruder, and the like. As the mixing form, there are ordinary melt mixing, multi-stage melt mixing using master pellets, solution blending and the like. Particularly, for mixing (D) component, latex of (D) component and (B)
A latex mixture of component and / or component (C) can be preferably used.

Further, an antioxidant, a flame retardant, an antistatic agent, an ultraviolet absorber, a plasticizer, a lubricant, a glass fiber, a carbon fiber, a filler such as calcium carbonate, a coloring agent, a metal powder and the like are further added to the composition of the present invention. It is also possible.

(Example) Hereinafter, the present invention will be further described with reference to examples. All parts and% in the examples are expressed on a weight basis.

Experimental Example- (1) Production of Component A Imidized Copolymer In an autoclave equipped with a stirrer, 100 parts of styrene, 50 parts of methyl ethyl ketone, and 24 parts of polybutadiene rubber cut into small pieces were charged and the inside of the system was replaced with nitrogen gas. After that, the rubber was dissolved by stirring overnight at room temperature. After adjusting the temperature to 80 ° C, 67 parts of maleic anhydride and benzoyl peroxide were added.
A solution prepared by dissolving 3 parts in 400 parts of methyl ethyl ketone was continuously added over 8 hours. After the addition, the temperature was kept at 80 ° C for another 3.5 hours. A portion of the viscous reaction liquid is sampled and the unreacted monomer is quantified by gas chromatography.
The polymerization rate was calculated. The polymerization rate of styrene was 98% and that of maleic anhydride was 99%. Then aniline 63 was added to the polymerization solution.
Parts (100% molar equivalents relative to added maleic anhydride), 1 part triethylamine, Irganox 1076 as antioxidant
(Ciba Geigy) 1 part was added, the temperature was raised at 140 ° C., and the mixture was reacted for 7 hours to carry out an imidization reaction. 100 reaction solution
After cooling to 0 ° C, the reaction solution was purged into a stainless steel vat.

It was vacuum dried at 180 ° C. for 3 hours and then pulverized to obtain a yellowish white powder copolymer. From C-13 NMR analysis, the conversion rate of acid anhydride groups to imide groups was 95%. This copolymer was designated as Polymer A-1.

Experimental Example- (2) Production of Component A Imidized Copolymer Except that the polybutadiene of Experimental Example- (1) was not used, the same operation as in Experimental Example- (1) was performed to prepare an imidized copolymer. Obtained. At this time, the polymerization rate was 99% styrene and 99% maleic anhydride, and the conversion rate to an imide group was 96%. This copolymer was designated as Polymer A-2.

Experimental Example- (3) Production of Component B Graft Copolymer 100 parts of polybutadiene latex (solid content 50%, average particle size 0.35 µ, gel content 88%), sodium stearate 1
Part, sodium formaldehyde sulfoxylate 0.1
Parts, 0.03 parts of tetrasodium ethylenediaminetetraacetic acid, 0.003 parts of ferrous sulfate and 200 parts of water were charged into an autoclave substituted with nitrogen gas. Temperature 65
After heating to ℃, 30% acrylonitrile and 70% styrene
% Of a monomer mixture of 50%, t-dodecyl mercaptan 0.2 part, and cumene hydroperoxide 0.2 part were continuously added over 4 hours, and after the addition was completed, polymerization was performed at 65 ° C. for 2 hours. The polymerization rate was 98% for both styrene and acrylonitrile. After adding an antioxidant to the obtained latex,
After salting out with calcium chloride, washing with water and drying, a white powdery polymer was obtained. This copolymer was designated as B.

Experimental Example- (4) Production of Component D Acrylic Copolymer 2 parts of sodium dodecylbenzene sulfonate, 0.1 part of sodium formaldehyde sulfoxylate, 0.01 part of tetrasodium ethylenediaminetetraacetic acid, 0.003 part of ferrous sulfate and water 130 parts were placed in an autoclave whose atmosphere was replaced with nitrogen gas. After heating the temperature to 65 ° C, n
-Butyl acrylate 14 parts, methyl methacrylate 6
And 2.5 parts of a 0.2% aqueous solution of potassium persulfate were added to initiate polymerization. At the same time as the initiation of polymerization, n-butyl acrylate 56
Part, methyl methacrylate 24 parts, potassium persulfate 0.25%
20 parts of aqueous solution was continuously added over 6 hours, and after addition was completed 65
Polymerization was carried out at ℃ for 1 hour. The obtained latex was salted out with calcium chloride, washed with water and dried to obtain a white powdery polymer. This copolymer was designated as D.

Experimental Example- (5) Method for Producing Mixture of D-Component Acrylic Copolymer and C-Component Copolymer 50 parts of latex obtained in Experimental Example- (4) (solid content concentration
39%) and 200 parts of an acrylonitrile-styrene resin latex consisting of 30% acrylonitrile and 70% styrene (concentration of solid content 35%) are salted out with calcium chloride, washed with water and dried to obtain a white powdery C component / A D component mixture was obtained. This copolymer mixture was designated as C / D.

Example 1 A mixture consisting of 30 parts of copolymer A-1 and 40 parts of copolymer B and 30 parts of copolymer mixture C / D was extruded by a screw extruder equipped with a 40 m / m devolatilizer and pelletized. After molding this composition into a test piece by injection molding, the physical properties were measured by the methods described below, and the results were as follows.

Vicat softening point 132 ° C Impact strength 17 kg / cm / cm Chemical resistance Good Good molded product appearance Good Good Example 2 Copolymer A-2 50 parts, Copolymer B 42 parts, Copolymer D
A mixture of 8 parts was treated in the same manner as in Example 1 and its physical properties were measured.

Vicat softening point 141 ° C Impact strength 10 kg / cm / cm Chemical resistance Good Good molded product appearance Good Good Example 3 40 parts of Copolymer A-2, 30 parts of Copolymer B, AS resin (Electrochemical Company , Acrylonitrile-styrene resin'AS-H ')
A mixture of 20 parts and Copolymer D 10 parts was treated in the same manner as in Example 1 and its physical properties were measured.

Vicat softening point 136 ° C Impact strength 12 kg ・ cm / cm Chemical resistance Good Good molded product appearance Good Comparative Example 1 40 parts of Copolymer A-2, 40 parts of Copolymer B, and the same as Example 3 A mixture consisting of 20 parts of AS resin was treated in the same manner as in Example 1 and its physical properties were measured.

Vicat softening point 137 ℃ Impact strength 15kg ・ cm / cm Chemical resistance Product cracks in molded product Appearance of molded product Good Good Comparative Example 2 Styrene monomer residue 90 according to the manufacturing method of Experimental Example- (1)
%, N-phenylmaleimide monomer residue 10% was produced as an imidized copolymer. A mixture of 40 parts of this imidized copolymer, 30 parts of copolymer B, 20 parts of the same AS resin as in Example 3 and 10 parts of copolymer D was treated in the same manner as in Example 1 and its physical properties were measured. .

Vicat softening point 105 ° C Impact strength 5 kg ・ cm / cm Chemical resistance Product cracks on molded product Appearance of molded product Delamination of surface (effect of invention) From the above, the composition of the present invention has heat resistance and impact strength. Of course, it is recognized that the chemical resistance and the appearance of the molded product are also excellent.

The physical properties were measured by the following methods.

(1) Vicat softening point: load 5 kg, according to ASTM D-1525.

(2) Impact strength: A thickness of 1/4 inch, notched Izod impact strength, according to ASTM D-256.

(3) Chemical resistance: Bend ASTM D-638 No. 1 dumbbell as shown in Fig. 1 and apply paint thinner F-2500 (Tanabe Chemical Co., Ltd.) to the dumbbell, and after 24 hours at room temperature, crack or dumbbell Those without crazes were rated good.

(4) Appearance of molded product ... The surface appearance of the injection-molded ASTM D-638 No. 1 dumbbell was visually determined.

Those with no abnormality were marked with ◯, and those with surface layer peeling were marked with x.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a method for testing the chemical resistance of a resin composition. 1 ... Jig, 2 ... ASTM D-638 No. 1 dumbbell.

Claims (1)

[Claims] 1. Component (A): 0 to 30 parts by weight of a rubber-like polymer, 40 to 80% by weight of an aromatic vinyl monomer residue, 20 to 60% by weight of an unsaturated dicarboxylic acid imide derivative residue, and maleic anhydride. An imidized copolymer consisting of 70 to 100 parts by weight of a monomer residue composed of 0 to 15% by weight of an acid monomer residue and 0 to 30% by weight of another vinyl monomer residue. %, The component (B): 5 to 80 parts by weight of a rubber-like polymer, 40 to 80% by weight of an aromatic vinyl monomer residue, 0 to 40% by weight of a vinyl cyanide monomer residue, and other vinyl monomers. 10 to 80% by weight of a graft copolymer consisting of 20 to 95 parts by weight of a monomer residue composed of 0 to 40% by weight of a monomer residue, and (C) component: an aromatic vinyl monomer residue 40. A copolymer comprising 0 to 80% by weight, 0 to 40% by weight of vinyl cyanide monomer residues and 0 to 40% by weight of other vinyl monomer residues, and (D) comprising : Thermoplastic resin composition characterized in that the glass transition temperature of from 1 to 20 wt% homopolymer or a copolymer of 20 ° C. or less of acrylic acid ester monomer.