JPH0737550B2 - Heat resistant resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition having excellent impact resistance, heat resistance and moldability, and more specifically to a polymer having an imide group in its side chain. A resin composition comprising a styrene polymer having an oxazoline group in a side chain and a styrene polymer and / or an aromatic polyether polymer. The resin composition of the present invention can be preferably used for automobile parts, electronic / electric parts, office equipment parts, precision machine parts and the like.

(Prior art and its problems) Although a polymer having an imide group in its side chain has good thermal stability and heat resistance, it has drawbacks of low impact strength and poor moldability. Therefore, as a method of maintaining heat resistance and improving impact resistance and moldability, a composition comprising a polymer having an imide group in a side chain, an aromatic polyether polymer and, if necessary, an impact strength reinforcing agent is used. Proposed. However, in this resin composition, the impact resistance is not sufficient because the compatibility between the polymer having an imide group and the aromatic polyether polymer is not sufficient, and There is a drawback that the surface layer of the injection molded product peels off.

(Means for Solving the Problems) The present invention was surprisingly studied as a result of intensive studies to improve the compatibility between the polymer having an imide group and the styrene-based polymer and / or the aromatic polyether-based polymer. It was found that the use of a styrene-based polymer having an oxazoline group in (2) markedly increases the compatibility, and accordingly, the impact resistance and the moldability are significantly improved, and the present invention has been achieved.

That is, the present invention comprises: (A) component: aromatic vinyl monomer residue 30 to 90% by weight, unsaturated dicarboxylic acid imide derivative residue 3 to 70% by weight, unsaturated dicarboxylic acid anhydride residue 0 to 20% by weight. % And 5 to 80 parts by weight of an imidized copolymer consisting of 0 to 40% by weight of a vinyl monomer residue other than these residues, and (B) component: a styrene-based polymer having an oxazoline group 3 to 60 parts by weight. Parts and (C) component: 5 to 80 parts by weight of a styrene polymer and / or an aromatic polyether polymer.

As the method for producing the polymer having an imide group in the side chain of the component (A) in the present invention, the first production method is an aromatic vinyl monomer, an unsaturated dicarboxylic acid imide derivative, an unsaturated dicarboxylic acid anhydride, and these. A method of copolymerizing a copolymerizable vinyl monomer mixture, and a second method of copolymerizing an aromatic vinyl monomer, an unsaturated dicarboxylic acid anhydride and a vinyl monomer mixture copolymerizable therewith. Examples include a method of reacting a polymer with ammonia and / or a primary amine to convert 40 to 100 mol% of an acid anhydride group into an imide group, and any method gives an imidized copolymer. be able to.

The aromatic vinyl monomer used for the first production of the imidized copolymer is styrene, α-methylstyrene, vinyltoluene, styrene-based monomers such as chlorostyrene and substituted monomers thereof, Of these, styrene is particularly preferred.

As the unsaturated dicarboxylic acid imide derivative, maleimide, N-methylmaleimide, N-butylmaleimide, N
-Maleimide derivatives such as -cyclohexylmaleimide and N-arylmaleimide (aryl groups include, for example, phenyl, 4-diphenyl, 1-naphthyl, methoxyphenyl, tolyl and halogen-substituted products thereof), N-methylitacon. Examples thereof include acid imides and itaconic acid imide derivatives such as N-phenylitaconic acid imide.

Examples of unsaturated dicarboxylic acid anhydrides include anhydrides such as maleic acid, itaconic acid and citraconic acid, with maleic anhydride being particularly preferred.

The aromatic vinyl monomer and unsaturated dicarboxylic acid anhydride used in the second production method are also as described in the first production method.

As the vinyl monomer copolymerizable with these, acrylonitrile, methacrylonitrile, vinyl cyanide monomers such as α-chloroacrylonitrile, acrylic acid ester monomers such as methyl acrylic acid ester, ethyl acrylic acid ester, Examples include methacrylic acid esters such as methyl methacrylic acid ester and ethyl acrylic acid ester, acrylic acid, vinyl carboxylic acid monomers of methacrylic acid, acrylic acid amide, methacrylic acid amide, and maleic anhydride in the first production method.

Ammonia and the first used in the imidization reaction in the second production method
The primary amine may be in either anhydrous or aqueous solution. Examples of primary amines include alkylamines such as methylamine, ethylamine, butylamine and cyclohexylamine, and aromatic amines such as chloro- or bromo-substituted alkylamines, aniline, tolylamine, naphthylamine and chloro- or bromo-substituted anilines. And halogen-substituted aromatic amines.

Further, when the imidization reaction is carried out in a solution state or a suspension state, it is preferable to use an ordinary reaction vessel, for example, an autoclave, and when it is carried out in a bulk molten state, an extruder equipped with a devolatilization device is also used. Good. A fusing medium may be present during imidization, and for example, a tertiary amine or the like is preferably used.

The temperature of the imidization reaction is about 50-350 ° C, preferably 1
It is from 00 to 300 ° C. When the temperature is lower than 50 ° C, the reaction rate is slow and the reaction requires a long time, which is not practical. On the other hand, when the temperature exceeds 350 ° C, the physical properties are deteriorated due to thermal decomposition of the polymer.

The amount of ammonia and / or primary amine used is 0.4 to 1.05 molar equivalent, preferably 0.5 to 1.00 molar equivalent, particularly preferably 0.6, relative to the unsaturated dicarboxylic acid anhydride.
~ 0.95 molar equivalents are preferred. If the amount is less than 0.4 molar equivalent, the acid anhydride group will increase in the imidized copolymer, and the thermal stability and hot water resistance will decrease, which is not preferable.

The imidized copolymer has an aromatic vinyl monomer residue of 30 to 90% by weight. Preferably 40 to 80% by weight, unsaturated dicarboxylic acid imide derivative residue 3 to 70% by weight, preferably 20 to 60% by weight,
Imidization consisting of 0 to 20% by weight, preferably 1 to 15% by weight of unsaturated dicarboxylic acid anhydride residues and 0 to 40% by weight, preferably 0 to 30% by weight of vinyl monomer residues copolymerizable therewith. It is a copolymer. The amount of aromatic vinyl monomer residue is
When it is less than 30% by weight, moldability and dimensional stability are impaired,
If it exceeds 90% by weight, heat resistance is impaired. If the amount of the unsaturated dicarboxylic acid imide derivative residue is less than 3% by weight, the effect of improving heat resistance is lost. On the other hand, when the amount of the unsaturated dicarboxylic acid imide residue exceeds 70% by weight, the resin composition becomes brittle and the moldability is significantly deteriorated. Further, when the unsaturated dicarboxylic acid anhydride residue exceeds 20% by weight, the thermal stability at the time of molding is deteriorated, which is not preferable. However, the unsaturated dicarboxylic acid anhydride residue is preferably 1 to 15% by weight, because the acid anhydride group and the styrene-based polymer having the oxazoline group of the component (B) partially react with each other, and thus (A) of the present invention is used. It is considered that the compatibility between the component and the component (C) is further improved. Further, when the amount of the copolymerizable vinyl monomer residue exceeds 40% by weight, dimensional stability and heat resistance are impaired.

Component (B) of the present invention, a styrene-based polymer having an oxazoline group, a styrene-based polymer such as styrene, vinyltoluene, and t-butylstyrene, and 2-isopropenyl-2-
It can be obtained by copolymerizing oxazoline. Copolymerization can be carried out by radical polymerization using a peroxide catalyst such as benzoyl peroxide, an azo catalyst such as azoisobutyronitrile as an initiator, and the polymerization method is a known method, that is, suspension polymerization, A method such as bulk polymerization or solution polymerization can be adopted. The amount of 2-isopropenyl-2-oxazoline is 0.1% by weight to 10% by weight, more preferably 0.5% by weight, based on the styrenic monomer.
To 7% by weight. If it is less than 0.1% by weight, the compatibility with the component (A) will be insufficient, and if it exceeds 10% by weight, the appearance of the molded article obtained from the finished composition will be poor. In addition, styrene is preferable as the styrene-based monomer.

Examples of the styrene polymer as the component (C) of the present invention include polystyrene, polyvinyltoluene, poly-t-butylstyrene, high-impact polystyrene, styrene-butadiene block polymer, hydrogenated styrene-butadiene block polymer and the like.

Resin composition obtained by blending the imidized copolymer of the component (A), the styrene polymer having an oxazoline group as the component (B), and the styrene polymer and / or the aromatic polyether polymer as the component (C). The products were specifically compatible with each other, resulting in a significant improvement in impact resistance and moldability.

In the resin composition of the present invention, component (A): imidized copolymer, component (B): styrene-based polymer having an oxazoline group, and component (C): styrene-based polymer and / or aromatic polyether-based polymer. The mixing ratio with the combination is (A) component: 8 to 80 parts by weight, preferably 20 to 60 parts by weight, (B) component: 3 to 60 parts by weight, preferably 5 to 40 parts by weight (C) component: 5 to It is in the range of 80 parts by weight, preferably 10 to 70 parts by weight.

The method for mixing the thermoplastic resin composition of the present invention is not particularly limited,
Known means can be used. Examples of the means include Banbury mixer, mixing roll, kneader, and 1
A shaft or twin screw extruder and the like can be mentioned. Examples of the mixing form include normal melt mixing, multi-stage melt mixing in which the components (A) and (B) are melt mixed with the component (C), and a solution is blended.

It is also possible to add an antioxidant, a flame retardant, an ultraviolet absorber, a plasticizer, a lubricant, an inorganic filler, a fiber such as glass or carbon, and a coloring agent to the composition of the present invention. In particular, in the case where the component (C) contains an aromatic polyether polymer, phosphoric acid esters such as triphenyl phosphate, trinonyl phenyl phosphate, and tricule are used as flame retardants for flame retarding the resin composition. It is useful to add dilvosphate.

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

Experimental Example (1) Production of an imidized copolymer obtained by polymerizing an aromatic vinyl monomer and an unsaturated dicarboxylic acid anhydride 100 parts of styrene and 50 parts of methyl isobutyl ketone in an autoclave equipped with a stirrer Then, the inside of the system was replaced with nitrogen gas. After raising the temperature to 83 ° C., a solution prepared by dissolving 67 parts of maleic anhydride and 0.2 part of benzoyl peroxide in 400 parts of methyl isobutyl ketone was added over 8 hours. After that, polymerization was carried out at 83 ° C. for another 4 hours. As a result of sampling a part of the viscous reaction liquid and quantifying the unreacted monomer by gas chromatography, the polymerization rate was styrene 99.
%, And maleic anhydride 99.5%. To the resulting copolymer solution, 54.3 parts of aniline and 0.9 part of 0.95 molar equivalent of maleic anhydride and 1 part of triethylamine were added and reacted at 40 ° C. for 7 hours. The imidized copolymer obtained by precipitation with methanol and vacuum drying was designated as copolymer A-1.

Experimental Example (2) Production of Imidized Copolymer of Aromatic Vinyl, Unsaturated Dicarboxylic Acid, and Copolymer of Vinyl Monomer Copolymerizable Therewith Instead of 100 parts of styrene in Experiment (1) To 100 parts of styrene and 17 parts of acrylonitrile, 67 parts of maleic anhydride to 50 parts
Except that 54.3 parts of aniline was replaced with 40.5 parts of aniline, the same operation as in Experimental Example (1) was performed to obtain an imide copolymer.
This was designated as copolymer A-2. The polymerization rate of this copolymer was 99% styrene, 95 acrylonitrile, and 98% maleic anhydride.

Example A styrene-based polymer having about 1% oxazoline group with the imidized copolymer A-1 or A-2 obtained in Experimental Examples 1 and 2 (Reactive Polystyrene XUS-40056.0 manufactured by Dow).
1) and high-impact polystyrene (Denkastyrol HI-U-2 manufactured by Denki Kagaku Kogyo Co., Ltd.) or aromatic polyether polymer (Copiace CPX100L manufactured by Mitsubishi Gas Chemical Co., Inc.) were blended in the proportions shown in Table 1, and this blended 40 things
It was extruded by a screw extruder equipped with a mmφ devolatilizer and pelletized. The physical properties were measured and are shown in Table 1.

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Claims (1)

[Claims] 1. Component (A): Aromatic vinyl monomer residue 30 to
90% by weight, unsaturated dicarboxylic acid imide derivative residue 3 to 70
% By weight, 0 to 20% by weight of unsaturated dicarboxylic acid anhydride residues and 0 to 40% by weight of vinyl monomer residues other than these residues
5 to 80 parts by weight of an imidized copolymer composed of (B) component: 3 to 60 parts by weight of a styrene-based polymer having an oxazoline group, and (C) component: a styrene-based polymer and / or an aromatic polyether. A resin composition comprising 5 to 80 parts by weight of a polymer.