JP2548310B2 - Method for producing heat-resistant resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a copolymer containing an aromatic vinyl monomer residue and an unsaturated dicarboxylic acid imide monomer residue as main components and a thermoplastic resin. The present invention relates to a method for producing a thermoplastic resin composition by mixing. The thermoplastic resin composition obtained by the present invention is excellent in heat resistance, impact strength and moldability, and is preferably used for automobile parts, electric parts, electronic parts, office equipment parts, household electric parts, medical equipment parts, camera parts and the like. be able to.

(Prior Art) Conventionally, a method for producing a copolymer comprising an aromatic vinyl monomer, maleic anhydride and another vinyl monomer (Japanese Patent Publication No.
-15829, Japanese Patent Publication No. 45-31953, Japanese Patent Publication No. 49-10156)
It has been known. Also proposed is a method for producing a thermoplastic copolymer having improved impact resistance by graft-polymerizing maleic anhydride, an aromatic vinyl monomer and / or a vinyl monomer copolymerizable therewith with a graft-polymerizable elastomer. (JP-A-48-42091, JP-A-49-28693, JP-A-49-28693)
53-78252, JP-A-53-80490).

However, the polymers obtained by copolymerizing these maleic anhydrides have a high heat distortion temperature, but in any case, the copolymers are easily decomposed by hot water and easily gelated and foamed by heat. Due to its drawbacks, there are significant restrictions in injection or extrusion processing, and there is the drawback that mechanical properties, especially impact strength, decrease when the processed product is contacted with water or steam or exposed to high temperatures. It was

For the purpose of improving these drawbacks, a method for producing a copolymer in which maleic anhydride is replaced with a maleimide derivative and a composition thereof have been proposed (US Pat. No. 3651171, US Pat. No. 3652726, JP-A-57-98536). issue).

(Problems to be Solved by the Invention) However, although these copolymers or compositions have improved heat stability and hot water resistance, they still have a drawback that they are still insufficient in impact strength, particularly falling weight impact strength.

(Means for Solving the Problems) The present invention has solved the above-mentioned drawbacks by, for example, previously melting a copolymer containing an unsaturated dicarboxylic acid imide monomer residue of the component (A), and then (B) It is intended to provide a thermoplastic resin composition which is excellent not only in heat resistance but also in impact strength by adding and mixing the thermoplastic resin as the component).

That is, the present invention relates to (A) aromatic vinyl monomer residue 30 to 80
% By weight, 20 to 60% by weight of unsaturated dicarboxylic acid imide monomer residues and 0 to 40 vinyl monomer residues copolymerizable therewith
A method for producing a heat-resistant resin composition, which comprises previously melting a copolymer containing 1% by weight and then adding and mixing the thermoplastic resin (B) in a molten or unmelted state.

 First, the component (A) will be described.

In the present invention, as the copolymer containing an unsaturated dicarboxylic acid imide monomer residue, i) an aromatic vinyl monomer and an unsaturated dicarboxylic acid anhydride are polymerized in the presence or absence of a rubbery polymer. A polymer obtained by imidizing the obtained copolymer, i
i) an imidized polymer obtained by polymerizing an aromatic vinyl monomer, an unsaturated dicarboxylic acid anhydride and a copolymerizable vinyl monomer with or without a rubbery polymer. Iii) Polymer in which aromatic vinyl monomer, maleimide and / or N-substituted maleimide are polymerized in the presence or absence of rubber-like polymer, iv) In the presence or absence of rubber-like polymer Below, there are aromatic vinyl monomers, maleimides and / or N-substituted maleimides, and polymers obtained by polymerizing vinyl monomers copolymerizable therewith.

Examples of the aromatic vinyl monomer include styrene and α-
Styrene monomers such as methylstyrene, vinyltoluene, and chlorostyrene and substituted monomers thereof, of which styrene and α-methylstyrene monomers are particularly preferable.

As the unsaturated dicarboxylic acid anhydride, for example, maleic anhydride, chloromaleic anhydride, itaconic anhydride,
Phenyl maleic anhydride or the like can be used, and maleic anhydride is particularly preferable. In addition, as vinyl monomers copolymerizable with these, vinyl cyanide monomers such as acrylonitrile, methacrylonitrile, α-chloroacrylonitrile; methyl acrylate, ethyl acrylate, butyl acrylate, etc. Acrylic ester monomer; Methyl methacrylate ester,
Methacrylic acid ester monomers such as ethyl methacrylic acid ester; vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid; and other acrylic acid amides, methacrylic acid amides, acenaphthylene and N-vinylcarbazole. Therefore, monomers such as acrylonitrile, acrylic acid ester and methacrylic acid ester, acrylic acid and methacrylic acid are preferable.

Examples of the N-substituted maleimide include N-methylmaleimide, N-butylmaleimide, N-arylmaleimide (aryl groups include, for example, phenyl, 4-diphenyl, 1-naphthyl, 2,6-diethylphenyl, 2,3- and 4 -Chlorophenyl, 4-bromophenyl and other mono- and dihalophenyl isomers, 2,4,6-trichlorophenyl, 2,4,6-tribromophenyl, 4-n-butylphenyl, 4-benzylphenyl, 2- And 3-, 4-methoxyphenyl and the like.

In the copolymers i) to ii) containing an imide group mentioned as examples of the component (A) in the present invention, methylamine, ethylamine, n-
Examples thereof include alkylamines such as propylamine, iso-propylamine, butylamine, pentylamine and cyclohexylamine; aromatic amines such as aniline and naphthylamine, and allogen-substituted aromatic amines such as chloro- or bromine-substituted aniline.

When the imidization reaction is carried out in a solution state or in a suspension state in a non-aqueous medium, it is preferable to use an ordinary reaction vessel, for example, an autoclave, but when it is carried out in a bulk molten state, an extruder equipped with a devolatilizer is used. You may use. The reaction temperature for imidization is about 80-350 ° C. As the solvent for imidization in a solution state, there are acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, tetrahydrofuran, dimethylformamide and the like. Among these, methyl ethyl ketone and methyl isobutyl ketone are preferable. The non-aqueous medium used for imidization in suspension in a non-aqueous medium includes aliphatic hydrocarbons such as heptane, hexane, pentane, octane, 2-methylpentane, cyclopentane and cyclohexane.

 Next, the component (B) will be described.

Examples of the thermoplastic resin to be added to the copolymer (A) containing an imide group as exemplified in i) to iv) are acrylonitrile-butadiene-styrene and / or α-methylstyrene copolymer, methylmethacrylate-butadiene-.
Styrene copolymer, acrylonitrile-ethylene and 1
Or propylene-styrene copolymer, acrylonitrile-styrene and / or α-methylstyrene copolymer, rubber modified styrene polymer, styrene-butadiene block copolymer, aromatic polycarbonate, aromatic polyester, nylon, polyphenylene oxide and styrene. 1 polymer selected from modified polyphenylene oxide
An example is a thermoplastic resin containing at least one species.

The copolymer of the component (A) in the present invention comprises aromatic vinyl monomer residues of 30 to 80% by weight, unsaturated dicarboxylic acid imide monomer residues of 20 to 60% by weight, and vinyl copolymerizable with these. It is a copolymer containing 0 to 40% by weight of a monomer residue, and when the amount of the aromatic vinyl monomer residue is less than 30% by weight, the moldability and dimensional stability characteristic of the aromatic vinyl compound are lost. Be seen. On the other hand, if the unsaturated dicarboxylic acid imide monomer residue is less than 20% by weight, the heat resistance is not sufficient, and if it exceeds 60% by weight, the copolymer becomes brittle and the moldability remarkably deteriorates.

In the method of the present invention, the copolymer of the component (A) is melted in advance, and then the thermoplastic resin of the component (B) is added and mixed. The thermoplastic resin as the component (B) may be added in either a molten or unmelted state. However, when the copolymer of the component (A) is not melted when the thermoplastic resin of the component (B) is added, for example, the mixed composition as shown in Comparative Example 1 has a high impact strength. I can't get anything.

As a device for preliminarily melting the copolymer containing the unsaturated dicarboxylic acid imide monomer residue as the component (A) and adding and mixing the thermoplastic resin as the component (B), a roll mill, a Banbury mixer, a kneader, a uniaxial extrusion Machines and twin-screw extruders can be considered. Among them, the twin-screw extruder (A)
It is particularly preferable to first plasticize and melt the components, and then add and mix the thermoplastic resin of component (B) in the molten or unmelted state from the middle of the cylinder of the twin-screw extruder.

The thermoplastic heat-resistant resin composition produced by the method of the present invention includes organic fiber, glass fiber, reinforcing material such as carbon fiber, calcium carbonate, talc, clay, filler such as aluminum hydroxide and heat stabilizer, An ultraviolet absorber, a plasticizer, a lubricant, a coloring agent, a foaming agent, a flame retardant, etc. can be added.

(Examples) Parts and% in Examples and Comparative Examples are based on weight.

Experimental Example (1) Manufacture of a polymer obtained by imidizing a copolymer obtained by polymerizing an aromatic vinyl monomer and an unsaturated dicarboxylic acid anhydride in the presence of a rubbery polymer, styrene in an autoclave equipped with a stirrer. 100 copies,
Then, 50 parts of methyl isobutyl ketone and 24 parts of polybutadiene cut into small pieces were charged, the system was replaced with nitrogen gas, and the mixture was stirred at room temperature for one day to dissolve the rubber. Temperature up to 83 ℃
After the temperature was raised, 67 parts of maleic anhydride, 0.2 parts of benzoyl peroxide, and 0.2 parts of azobisisobutyronitrile were dissolved in 400 parts of methyl isobutyl ketone, and the solution was added over 8 hours. After the addition, a part of the viscous reaction liquid kept at 83 ° C. for 3 hours was sampled and the unreacted monomer was quantified by gas chromatography. As a result, the polymerization rate was 98%. 63.6 parts of aniline and 2 parts of triethylamine, which are equivalent to maleic anhydride, were added to the obtained copolymer solution.
The reaction was carried out at 140 ° C for 7 hours. The imidized polymer obtained by the degassing treatment is referred to as polymer A.

Experimental Example (2) Production of a polymer obtained by imidizing a copolymer obtained by polymerizing an aromatic vinyl monomer and an unsaturated dicarboxylic acid anhydride in the absence of a rubber-like polymer, the polybutadiene of Experimental Example (1) and Except for not using azobisisobutyronitrile, the same operation as in Experimental Example (1) was performed to obtain an imidized polymer. This is referred to as polymer B.

Example 1 Using a 50 mm same-direction twin-screw extruder equipped with a feeder capable of adding a thermoplastic resin in the middle of a cylinder, the polymer A obtained in Experimental Example (1) was fed from the hopper side at a cylinder temperature of 260 ° C. to 60 kg / hr. And was plasticized and melted.
At the same time, the acrylonitrile / butadiene / styrene copolymer (ABS GR-3 manufactured by Denki Kagaku Co., Ltd.)
000) was fed at 60 kg / hr and mixed and extruded into pellets. The pellets were injection-molded at 260 ° C., predetermined test pieces were prepared, and the physical properties were measured.

 The measurement results of the examples are shown in Table 1 below.

Example 2 Instead of polymer A, polymer B obtained in experimental example (2)
Example 1 was repeated except that

Example 3 Polymer A obtained in Example (1) was fed at 80 kg / hr from the hopper side at the cylinder temperature of 260 ° C. using the same 50 mm same-direction twin-screw extruder as in Example 1, and was plasticized and melted. .
At the same time, an acrylonitrile / styrene copolymer (AS-H, manufactured by Denki Kagaku Co., Ltd.) was fed from the middle of the cylinder at 40 kg / hr, and mixed and extruded into pellets. The pellets and the same acrylonitrile / butadiene / styrene copolymer pellets used in Example 1 were mixed in a tumbler mixer at a weight ratio of 1/1, and then, using a 50 mm co-directional twin-screw extruder, at a cylinder temperature of 260 ° C. 120kg / hr from the hopper side
And extruded into pellets. The physical properties of the pellets were measured in the same manner as in Example 1.

Comparative Example 1 The polymer A obtained in Example (1) and the same acrylonitrile-butadiene-styrene copolymer pellets used in Example 1 were mixed in a tumbler mixer at a weight ratio of 1/1, and then mixed at 50 mm. Using a unidirectional twin-screw extruder, the hopper was fed at a cylinder temperature of 260 ° C. at 120 kg / hr to extrude and pelletize. The physical properties of the pellets were measured in the same manner as in Example 1.

The physical properties shown in the table were measured by the following methods.

(1) Vicat softening temperature Load 5 kg, measured according to JIS K7206.

(2) I zod impact strength Thickness 1/4 ″, measured according to ASTM D256.

(3) Drop weight impact strength A spherical test piece with a plate thickness of 2 mm and a mass of 1 kg was used as a square test piece and was measured according to JIS K7211.

(Effects of the Invention) The present invention is obtained by previously melting a copolymer containing an aromatic vinyl monomer residue and an unsaturated dicarboxylic acid imide monomer residue as main components, and then adding and mixing a thermoplastic resin. This is a method for producing a thermoplastic resin in which impact strength, particularly falling weight impact strength, is remarkably improved.

Claims (1)

(57) [Claims] 1. A) Aromatic vinyl monomer residue (30 to 80% by weight), unsaturated dicarboxylic acid imide monomer residue (20 to 60% by weight)
And a copolymer containing 0 to 40% by weight of a vinyl monomer residue capable of being copolymerized therewith, after which the thermoplastic resin (B) is added and mixed in a molten or unmelted state. A method for producing a heat resistant resin composition.