JPS6346780B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermoplastic resin composition having excellent heat resistance and impact resistance. Many studies have been conducted to improve the heat resistance of styrenic resins. For example, a graft copolymer in which a copolymer containing maleic anhydride as a copolymerization component is grafted onto a rubber-like polymer has been grafted with ammonia or primary A maleimide graft copolymer modified with a rubbery polymer imidized with an amine (Japanese Unexamined Patent Publication No. 100104/1983) and a rubber-modified maleimide graft copolymer obtained in this manner were mixed with styrene/acrylon. It is known that compositions blended with vinyl polymers such as tolyl copolymers have excellent heat resistance and impact resistance. Sexuality cannot be fully satisfied. Therefore, the present inventors conducted intensive studies with the aim of obtaining a thermoplastic molding material with a sufficiently good balance between heat resistance, represented by heat distortion temperature, and impact resistance, represented by impact strength. In contrast to a maleimide-based graft copolymer obtained by imidizing a graft copolymer obtained by graft-polymerizing a vinyl monomer containing maleic anhydride, a vinyl monomer containing a glycidyl group in a rubber-like polymer is used. The inventors have discovered that the above object can be effectively achieved by blending a specific graft copolymer obtained by graft polymerizing polymers, and have thus arrived at the present invention. That is, the present invention comprises (A) 50 to 80 parts by weight of an aromatic vinyl monomer in the presence of 20 to 80 parts by weight of a rubbery polymer;
α,β unsaturated carboxylic acid glycidyl ester 0.5
Monomer mixture 20 consisting of ~15% by weight and 0 to 50% by weight of other vinyl monomers copolymerizable with these
10 to 90 parts by weight of a graft copolymer obtained by graft polymerization of ~80 parts by weight, 50 to 80 parts by weight of an aromatic vinyl monomer in the presence of 5 to 40 parts by weight of (B) rubbery polymer,
A graft copolymer obtained by graft polymerizing 60 to 95 parts by weight of a monomer mixture consisting of 5 to 50% by weight of maleic anhydride and 0 to 30% by weight of a vinyl monomer copolymerizable with maleic anhydride is prepared by adding ammonia or 10 to 90 parts by weight of a maleimide graft copolymer obtained by reacting with a primary amine, and (C) an aromatic vinyl monomer and other vinyl monomers copolymerizable with this are copolymerized. The present invention provides a thermoplastic resin composition comprising 0 to 50 parts by weight of a vinyl copolymer such that the total of (A), (B) and (C) is 100 parts by weight. In the present invention, although the clear mechanism behind the expression of the above effects is not clear, (A) the glycidyl group contained in the graft copolymer and (B) the presence of maleimide units or a small amount in the maleimide-based graft copolymer This is presumed to be due to the formation of a chemical bond between the carboxyl group and anhydrous carboxyl group. In the present invention, the rubbery polymer that is a constituent component of (A) the graft copolymer and (B) the maleimide-based graft copolymer is a polymer having a rubbery state and a glass transition temperature of -10°C or lower, For example, diene rubbers such as polybutadiene rubber, acrylonitrile-butadiene copolymer rubber (NBR), styrene-butadiene copolymer rubber (SBR), acrylic rubbers such as polybutyl acrylate, polypropyl acrylate, and ethylene-propylene-diene rubbers. Examples include rubber (EPDM). However, the ratio of the rubbery polymer to the monomer mixture consisting of the aromatic vinyl monomer, α, β unsaturated carboxylic acid glycidyl ester, and other vinyl monomer in the graft copolymer (A) is Importantly, it is necessary to polymerize 20 to 80 parts by weight, in particular 30 to 70 parts by weight, of the above monomer mixture in the presence of 20 to 80 parts by weight, in particular 30 to 70 parts by weight, of the rubbery polymer. If the proportion of the rubbery polymer is less than 20 parts by weight, the resulting composition will not have sufficient impact resistance, and if it exceeds 80 parts by weight, the resulting composition will have poor gloss, which is undesirable. In addition, the α,β-unsaturated carboxylic acid glycidyl ester in the graft copolymer (A) has the general formula (In the formula, R is a hydrogen atom, a lower alkyl group, or a lower alkyl group substituted with a glycidyl ester group.) Specifically, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate Among them, glycidyl methacrylate is preferred. The proportion of α,β unsaturated carboxylic acid glycidyl ester in the monomer mixture constituting the graft copolymer (A) is particularly important, and is preferably from 0.5 to 30% by weight, particularly from 1 to 20% by weight. When α,β unsaturated carboxylic acid glycidyl ester is less than 0.5% by weight,
(B) It seems that the reaction with the maleimide-based graft copolymer is insufficient, so the impact strength is insufficient, and
If it exceeds 30% by weight, the melt viscosity of the resulting composition will become significantly high, which is not preferable. The aromatic vinyl monomers used in (A) the graft copolymer, (B) the maleimide graft copolymer, and (C) the vinyl copolymer include styrene, α-
Methylstyrene, P-methylstyrene, P-t-
These include styrene monomers such as butylstyrene and chlorostyrene, and substituted monomers thereof, and among these, styrene and α-methylstyrene are particularly preferred. The ratio of the rubbery polymer to the monomer mixture consisting of an aromatic vinyl monomer, maleic anhydride, and other vinyl monomers in the maleimide graft copolymer (B) used in the present invention is important. 95 to 60 parts by weight, especially 90 parts by weight, of the above monomer mixture in the presence of 5 to 40 parts by weight, especially 10 to 35 parts by weight of a rubbery polymer.
It is necessary to polymerize with ~65 parts by weight. If the proportion of the rubbery polymer is less than 5 parts by weight, the resulting composition will not have sufficient impact resistance, and if it exceeds 40 parts by weight, the mechanical strength of the resulting composition will decrease, which is preferable. do not have. Furthermore, the proportion of maleic anhydride in the monomer mixture constituting the maleimide-based graft copolymer (B) of the present invention is particularly important, and is 5 to 50% by weight, particularly 10 to 50% by weight.
A range of 45% by weight is preferred. Maleic anhydride is 5
If the amount is less than 50% by weight, the heat distortion temperature of the maleimide-based graft copolymer obtained by imidization and thus the composition of the present invention will be extremely low; if it exceeds 50% by weight,
This is not preferable because the melting temperature becomes too high and moldability is significantly impaired. Other vinyl monomers constituting the (A) graft copolymer, (B) maleimide graft copolymer, and (C) vinyl copolymer of the present invention include acrylonitrile, methacrylonitrile, etc. Examples include vinyl cyanide monomers, (meth)acrylic acid ester monomers represented by methyl methacrylate, methyl acrylate, etc., and these can be used in combination. Among these, acrylonitrile and methyl methacrylate are particularly preferred. (A) The graft copolymer can be produced by ordinary emulsion polymerization, and (C) the vinyl copolymer can be produced by ordinary suspension polymerization, emulsion polymerization, bulk polymerization, solution polymerization, etc. In addition, (B) maleimide-based graft copolymer is a monomer consisting of an aromatic vinyl monomer, maleic anhydride, and other vinyl monomers copolymerizable with these in the presence of a rubbery polymer. In particular, organic A preferred method is to react with ammonia or a primary amine in a solvent at a temperature of 0 to 75°C, remove the organic solvent, and then conduct dehydration and ring closure by heating at a temperature of 150°C or higher. Specific examples of primary amines used here include methylamine, ethylamine, n-propylamine, iso-propylamine,
Examples include butylamine, aniline, tolylamine, naphthylamine, and halogen-substituted aniline. The resin composition of the present invention is obtained by blending the above-mentioned (A) graft copolymer, (B) maleimide-based graft copolymer, and (C) vinyl-based copolymer, and the blending ratio of these three components is (A) is 10 to 90 parts by weight, especially 15 to 60 parts by weight, and (B) is 10 to 90 parts by weight, especially 15
~60 parts by weight and (C) 0 to 50 parts by weight, especially 0 to 45
parts by weight (total 100 parts by weight). If the amount of graft copolymer (A) is less than 10 parts by weight, only a composition with extremely low impact strength will be obtained, and if it exceeds 90 parts by weight, the mechanical strength, represented by tensile strength, will be significantly reduced. It is not desirable because it Furthermore, if the amount of the maleimide-based graft copolymer (B) is less than 10 parts by weight, only a composition with an extremely low heat distortion temperature will be obtained, and if it exceeds 90 parts by weight, the mechanical strength will be significantly lowered, which is not preferable. There are no restrictions on the method of blending the above (A) graft copolymer, (B) maleimide graft copolymer, and (C) vinyl copolymer. A method is adopted in which the materials are supplied to an extruder at a ratio of 1 to 1, and then melt mixed. Moreover, various properties can be exhibited by further blending other polymers with the thermoplastic resin composition of the present invention. Examples of such polymers include polyamide polymers such as nylon, polyester polymers such as polyethylene terephthalate and polybutylene terephthalate, polycarbonates, and polyacetals. In addition, when adding at least one selected from organic sulfonates and sulfate ester salts to the thermoplastic resin composition of the present invention, if desired,
A composition with further improved impact resistance and weather resistance can be obtained. The organic sulfonate and sulfuric ester salt mentioned here have the general formula R(SO ₃ M)n
and R(OSO ₃ M)n.
However, in the formula, M represents a metal atom, R represents an organic group, and n represents an integer of 1 or more. Preferred examples of M include alkali metal salts such as lithium, sodium and potassium, alkaline earth metals such as magnesium, calcium, strontium and barium, zinc and aluminum. Preferred examples of R include phenyl, α-naphthyl, β-naphthyl, dodecyl phenyl, dodecylnaphthyl, allyl, methacryl, and high molecular weight substances such as polystyrene and polyethylene glycol. A preferable example of the organic sulfonate is the general formula (However, in the formula, M is lithium, sodium, potassium, calcium, and R' and R'' are methyl, ethyl, phenyl, 2-hydroxyethyl, 4-hydroxybutyl.) Compounds represented by the formula, sodium dodecylbenzenesulfonate , sodium dodecylnaphthalenesulfonate, sodium methacrylsulfonate, potassium 1,5-naphthalenedisulfonate, formalin condensate of naphthalenesulfonate, sodium salt of sulfonated polystyrene, etc. Preferred examples of the sulfuric ester salt include potassium lauryl sulfate, These include calcium stearyl sulfate, barium stearyl sulfate, sodium polyoxyethylene ether sulfate, sodium polyoxyethylene dodecyl phenyl ether sulfate, etc. Two or more of these organic sulfonates and sulfate ester salts may be used in combination. The amount of the organic sulfonate and sulfuric acid ester salt added is 10 parts by weight or less, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the thermoplastic resin composition.
If the amount exceeds 10 parts by weight, undesirable phenomena such as worsening of the color tone of the composition will occur. In addition, the thermoplastic resin composition of the present invention may be added with ordinary hindered phenolic antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants to further improve thermal stability, or may be added with lubricants. It is also possible to further improve fluidity. Depending on the purpose, fiber reinforcing agents such as glass fiber and carbon fiber,
Inorganic fillers, colorants, pigments, conductive materials, etc. can also be blended. Furthermore, flame retardation can be achieved by mixing general halogenated organic compound flame retardants such as tetrabromobisphenol A, decabromobiphenyl ether, and brominated polycarbonate with antimony oxide into the resin composition of the present invention. be. As explained above, the thermoplastic resin composition of the present invention has an excellent balance of heat resistance, typified by heat distortion temperature, and mechanical properties, typified by impact strength, and can be used in a variety of applications that take advantage of these properties. It is expected to be applied to The present invention will be further explained below using reference examples and examples. In the Reference Examples and Examples, the heat distortion temperature was measured according to ASTM D-648-56, the Izot impact strength was measured according to ASTM D-256-56 Method A, and the tensile strength at break was measured according to ASTM 638-61T.
In addition, the number of parts means parts by weight, and the number of parts means percent by weight. Reference Example 1 [Preparation of graft copolymer (A-1)] Polybutadiene latex (solid content 53%) was placed in 15 stainless steel autoclaves equipped with a stirring device, a heating device, and a device for continuously charging monomers and polymerization initiators. , gel content 90%, average particle size 0.36μ) 5.6
Kg, glucose 18g, sodium pyrophosphate 15g,
0.2 g of ferrous sulfate and 1.1 kg of deionized water were charged, and the internal temperature was raised to 65°C while stirring. on the other hand,
Separately, 1500g of styrene, 470g of acrylonitrile,
A polymerization initiator mixture was prepared consisting of a monomer mixture consisting of 50 g of glycidyl methacrylate and 10 g of tert-dodecyl mercaptan, 14 g of cumene hydroperoxide (initiator), 84 g of potassium oleate and 760 g of deionized water. When the temperature inside the polymerization tank reaches 65℃, add the above monomer mixture for 3 hours and then start adding the monomer mixture again.
After 30 minutes, the polymerization initiator mixture was continuously charged into the polymerization tank over a period of 3 hours and 30 minutes. After the completion of charging the polymerization initiator mixture, the reaction was continued for an additional hour to carry out emulsion polymerization. The conversion rate after the completion of polymerization was 95% based on the total monomer. Next, the latex after completion of polymerization is coagulated, and after drying, a graft copolymer (A
-1) I obtained 5 kg. Reference Example 2 [Preparation of graft copolymer (A-2)] The monomer mixture in Reference Example 1 was styrene 1400
Emulsion polymerization was carried out in the same manner as in Reference Example 1, except that 450 g of acrylonitrile, 150 g of glycidyl methacrylate, and 10 g of tert-dodecyl mercaptan were used.
It was %. After the polymerization, the latex was coagulated and dried to obtain 5 kg of a white powder graft copolymer (A-2) having a rubber content of 60% and a glycidyl methacrylate content of 3%. Reference Example 3 [Preparation of graft copolymer (A')] The monomer mixture in Reference Example 1 was styrene 1500
Emulsion polymerization was carried out in the same manner as in Reference Example 1, except that the amounts used were 480 g of acrylonitrile, and 10 g of tert-dodecyl mercaptan, and the conversion rate after completion of the polymerization was 98% based on the total monomer. After the polymerization, the latex was coagulated and dried to obtain 5 kg of a white powder graft copolymer (A') having a rubber content of 60%. Reference Example 4 [Preparation of maleimide-based graft copolymer (B-1)] In a polymerization tank equipped with a stirrer and a reflux condenser, 25 parts of polybutadiene rubber "Diene NF-55A" (manufactured by Asahi Kasei Corporation) and 59.6 parts of styrene were added. After purging the system with nitrogen gas, it was stirred at room temperature all day and night.
Rubber was dissolved in styrene. To this, 71.4 parts of methyl ethyl ketone and 0.3 parts of benzoin peroxide (initiator) were charged and dissolved. Separately, a solution was prepared in which 40.4 parts of maleic anhydride was dissolved in 45.2 parts of methyl ethyl ketone. After the temperature inside the tank was set to 80°C, a maleic anhydride-methyl ethyl ketone solution was supplied to the polymerization tank at a rate of 21.4 parts/hr for 4 hours. After supplying, keep at 80℃ for another 2 hours.
and then cooled to obtain a milky white viscous liquid. The reaction solution was sampled, and unreacted monomers were quantified by gas chromatography. No maleic anhydride was detected, and the polymerization rate was 94%. 25.4 parts of aniline and 25.4 parts of methyl ethyl ketone were added to the reaction solution, and the mixture was reacted at room temperature for 30 minutes.
This reaction solution was added to toluene, and the solid content was dried separately. This was heated to 250℃ using a Brabender.
Knead for 15 minutes to perform imide ring closure, and rubber 18
%, a maleimide-based graft copolymer (B-1) containing 48% N-phenylmaleimide was prepared. Reference Example 5 [Preparation of maleimide-based graft copolymer (B-2)] In the same polymerization tank as in Reference Example 4, 20 parts of polybutadiene rubber "Diene NF-55A" (manufactured by Asahi Kasei Corporation) and 58.6 parts of styrene were charged. After purging the system with nitrogen gas, the mixture was stirred at room temperature all day and night to dissolve the rubber in styrene. To this, 71.4 parts of methyl ethyl ketone and 0.3 parts of benzoyl peroxide (initiator) were charged and dissolved. Meanwhile, apart from maleic anhydride 47.6
A solution was prepared by dissolving 53.3 parts of methyl ethyl ketone. After the temperature inside the tank was set to 80°C, a maleic anhydride-methyl ethyl ketone solution was supplied to the polymerization tank at a rate of 25.2 parts/hr for 4 hours. After the supply was completed, the mixture was kept at 80° C. for another 2 hours, and then cooled to obtain a milky white viscous liquid. Sample the reaction solution,
When unreacted monomers were quantified by gas chromatography, maleic anhydride was not detected and the polymerization rate was 95%. 25.4 parts of aniline and 28.6 parts of methyl ethyl ketone were added to the reaction solution, and the mixture was reacted at room temperature for 30 minutes. This reaction solution was added to toluene, and the solid content was dried separately. This was kneaded for 15 minutes at 270°C using a bran bender to perform imide ring closure.
A maleimide-based graft copolymer (B-2) containing 13% rubber and 56% N-phenylmaleimide was prepared. Example 1 The glycidyl methacrylate-containing graft copolymer (A
-1,2), rubber content 60% prepared in Reference Example 3
A graft copolymer (A') that does not contain glycidyl methacrylate, a maleimide graft copolymer (B-1, 2) prepared in Reference Examples 4 and 5, and a styrene-acrylonitrile copolymer with an acrylonitrile content of 28%. (SAN) and sodium dodecylbenzenesulfonate (SDBS) were melt-extruded using an extruder according to the compounding ratios shown in Table 1, and then injection molded, and the physical properties of the obtained test pieces were measured. The measurement results of heat distortion temperature, Izot impact strength and tensile breaking strength are shown in Table 1 along with the blending ratio.

[Table] As is clear from Table 1, composition No. of the present invention.
No. 1 to No. 5 were excellent in heat distortion temperature, isodt impact strength, and tensile strength at break, but when a graft copolymer (A') containing no glycidyl group was used (No. 6) If the compounding ratio of the present invention is not met (Nos. 7 to 10), only a composition can be obtained which is inferior in any one of heat distortion temperature, Izot impact strength, and tensile strength at break.

Claims (1)

[Claims] 1 (A) In the presence of 20 to 80 parts by weight of a rubbery polymer, 50 to 80% by weight of an aromatic vinyl monomer, 0.5 to 15% by weight of α, β unsaturated carboxylic acid glycidyl ester, and copolymerizable with these. Other vinyl monomers 0~
In the presence of 10 to 90 parts by weight of a graft copolymer obtained by graft polymerizing 20 to 80 parts by weight of a monomer mixture consisting of 50% by weight, and 5 to 40 parts by weight of (B) a rubbery polymer, aromatic vinyl-based 60 to 60% monomer mixture consisting of 50 to 80% by weight of a monomer, 5 to 50% by weight of maleic anhydride, and 0 to 30% by weight of a vinyl monomer copolymerizable with these
Maleimide-based graft copolymer 10 to 90 obtained by reacting a graft copolymer obtained by graft polymerizing 95 parts by weight with ammonia or a primary amine
(A), (B ) and (C) in a total amount of 100 parts by weight.