JPH046216B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermoplastic resin composition having excellent heat resistance, impact resistance, and melt flowability. Thermoplastic resins such as methacrylic resins, styrene resins, and vinyl chloride resins are used for various purposes due to their properties, but they have the drawbacks of insufficient heat resistance and low impact resistance. ing. Therefore, in recent years, for example, Japanese Patent Application Laid-Open No. 55-7873
As described in the publication, a thermoplastic with improved heat resistance and impact resistance is obtained by graft polymerizing a monomer mixture consisting of α-methylstyrene, methyl meccrylate, and acrylonitrile in the presence of a diene rubber. A method for obtaining a resin composition, or a graft copolymerization method in which a monomer mixture of α-methylstyrene, acrylonitrile, and methyl methacrylate is graft-polymerized in the presence of a diene rubber as described in JP-A-57-14637. Union and α
- A method has been proposed in which a vinyl chloride polymer with improved heat resistance and impact resistance is obtained by mixing a blend with a copolymer containing a methylstyrene structural unit into a vinyl chloride polymer. However, the method using the α-methylstyrene structural unit-containing polymer has the disadvantage that α-methylstyrene cannot be homopolymerized by ordinary radical polymerization, and the copolymerization reactivity is also low. As a method to improve this, a method of copolymerizing other ethylenic monomers that can be copolymerized with α-methylstyrene has been proposed, but due to the dilution effect of the other ethylenic monomers that are copolymerized, At present, the heat resistance contribution of the α-methylstyrene segment is not fully demonstrated. As another method, as described in JP-A-57-125241, a copolymer consisting of styrene, maleic anhydride and other copolymerizable ethylenic monomers is mixed with ammonia or a primary amine. thermally stable blends of reacted isidized polymers and rubbery graft (co)polymers;
A resin composition with excellent impact resistance has been disclosed, but this resin composition has problems such as poor thermal decomposition resistance and low melt fluidity due to thermal discoloration due to melting because it contains a nitrogen atom in the isido ring. arise.
Furthermore, ABS resin,
A method has been disclosed in which polycarbonate is blended with a copolymer using MBS resin and alkyl acrylate rubber, but this method has problems with the compatibility of the resins to be mixed. No composition is obtained. As mentioned above, the current situation is that none of the methods proposed so far have been developed that can satisfy all of the requirements of heat resistance, melt fluidity, and impact resistance. In view of this situation, the present inventors conducted various studies and found that heat resistance can be improved by blending a polymer containing a glutaric anhydride ring structural unit with a graft copolymer based on a rubbery polymer. They discovered that a resin composition with excellent impact resistance and melt flowability could be obtained, and completed the present invention. That is, the gist of the present invention is that (A) 10 to 90% by weight of a polymer containing glutaric anhydride ring structural units and (B) 5 to 80% by weight of a rubbery polymer containing an ethylenically unsaturated monomer. The present invention is a thermoplastic resin composition comprising 5 to 90% by weight of a graft copolymer obtained by graft polymerizing 95 to 20% by weight of polymer. The polymer (A) containing a glutaric acid ring structural unit used in the present invention has the following general formula: A polymer or _copolymer containing a glutaric anhydride ring structural unit represented _by It is a combination.
In the present invention, polymers or copolymers with any chemical structure can be applied as long as they contain the glutaric anhydride structural unit represented by the above general formula (1), and the manufacturing method for obtaining them is as follows: Although not particularly limited, for example, a homopolymer or copolymer of (meth)acrylic acid, tert-butyl (meth)acrylate, or a copolymer of at least one thereof and another copolymerizable ethylene monomer. 150～
Examples include methods such as carrying out a thermal decomposition reaction at a temperature range of 450°C, preferably 180 to 350°C.
(meth)acrylic acid or tert-butyl (meth)
Other copolymerizable ethylenic monomers used to obtain copolymers with acrylates include, for example, styrene, substituted styrenes such as chlorostyrene, and olefins such as alpha-methylstyrene, ethylene, propylene, acrylonitrile, methyl ( Carbon such as meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, lauryl(meth)acrylate, cyclohexyl(meth)acrylate, benzyl(meth)acrylate, etc. Alkyl (meth)acrylates and fluorinated alkyl (meth)acrylates having aliphatic or aromatic functional groups of numbers 1 to 18
Examples include acrylate. It is desirable that the obtained polymer be one that is difficult to discolor upon heating and one that does not have an intermolecular cross-linked structure, and from this point of view, the remaining components in the polymer containing a glutaric anhydride ring structure of the present invention are Methacrylic monomers and styrene monomers such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, and lauryl methacrylate are preferred. Particularly preferred are methyl methacrylate and styrene monomer. Furthermore, among the (meth)acrylic acid and tert-butyl (meth)acrylate which are raw materials for forming the glutaric anhydride ring structural unit, methacrylic acid and tert-butyl methacrylate are preferred for the purpose of heat resistance. The polymer having a glutaric anhydride ring structure unit used in the present invention can be used as long as it has a glutaric anhydride ring structure in the polymer, but from the viewpoint of heat resistance, it is preferable to contain it in an amount of 5% by weight or more. preferable. The graft copolymer (B) constituting the composition of the present invention is one obtained by polymerizing an ethylenic monomer or a mixture thereof in the presence of a rubbery polymer. Rubbery polymers used to obtain the graft copolymer include, for example, diene rubbers such as polybutadiene rubber (PBd), acrylonitrile/butadiene copolymer rubber (NBR), and styrene/butadiene copolymer rubber (SBR). , polybutyl acrylate, polypropyl acrylate, poly-
Acrylic rubber (AR) such as 2-ethylhexyl acrylate and ethylene/propylene/non-conjugated diene rubber (EPDM) can be used. In addition, grafting (co) to this rubbery polymer
Examples of ethylenic monomers and mixtures thereof used for polymerization include styrene, acrylonitrile, methyl methacrylate, α-methylstyrene, aromatic vinyl monomers such as styrene α-methylstyrene, and maleic anhydride. By using combinations and vinyl monomers copolymerizable with them, the effects of the present invention can be further enhanced and characteristics can be achieved depending on the purpose. The method for grafting (co)polymerizing the ethylenic monomer or a mixture thereof onto the rubbery polymer is not particularly limited, and may include known methods such as solution polymerization, emulsion polymerization, bulk polymerization, and/or suspension polymerization. can be adopted. The graft copolymer used in the present invention must contain a rubbery polymer in an amount of 5 to 80% by weight, preferably 15 to 75% by weight. Therefore, the ratio (weight) of rubber polymer and ethylenic monomer or mixture thereof when obtaining a graft copolymer
contains 5 to 80% by weight of rubbery polymer, preferably 15 to 80% by weight.
75% by weight, 20-95% by weight of ethylenic monomers or mixtures thereof, preferably 25-85% by weight. If the content of the rubbery polymer in the graft copolymer is less than 5% by weight, impact resistance will decrease. 80 again
If it exceeds % by weight, the mechanical properties and uniform dispersibility of the rubbery polymer will deteriorate, and as a result, the impact resistance will also decrease. The proportions of the polymer containing a glutaric anhydride ring structural unit and the graft copolymer containing a rubbery polymer constituting the composition of the present invention are 10 to 95% by weight, preferably 20 to 85% by weight, respectively. 5 to 90% by weight, preferably 15 to 75% by weight. If the content of the polymer containing a glutaric anhydride ring structural unit in the composition is less than 10% by weight, good heat resistance effects cannot be expected, and if it exceeds 95% by weight, good impact resistance cannot be expected.
Furthermore, if the amount of the graft copolymer containing the rubbery polymer in the composition is less than 5% by weight, good impact resistance effects will not be observed, and if it exceeds 90% by weight, good heat resistance effects will not be observed. Unfavorable in some respects. The composition of the present invention can generally be obtained by, for example, dry processing or latex blending of a polymer containing the above-mentioned glutaric anhydride ring structural unit and a graft copolymer containing a rubbery polymer. As another method, it can also be obtained, for example, by polymerizing an ethylenic monomer or a mixture thereof in the presence of a polymer containing a glutaric anhydride ring structural unit and a rubbery polymer. In addition, in the composition of the present invention, if necessary, a polymer or copolymer obtained by polymerizing an ethylenic monomer or a mixture thereof in an amount of 85% by weight or less, preferably 65% by weight or less based on the composition. Coalescence (C) can also be added. If the amount added exceeds 85% by weight, it is unfavorable in terms of impact resistance and heat resistance. Examples of the above-mentioned ethylenic monomers include styrene, α-substituted styrene, fluorostyrene, benzene-substituted styrene, olefins such as ethylene and propylene, acrylonitrile, and monomers such as alkyl (meth)acrylates. It consists of a mixture thereof. The composition of the present invention improves thermal stability by adding a hindered phenol antioxidant, a phosphorus antioxidant, and a sulfur antioxidant, as well as a lubricant etc. It can be added to further improve fluidity. Furthermore, glass fibers, carbon fibers, inorganic fillers, pigments, and dyes can be blended according to the purpose. Further, flame retardation can be achieved by blending a general halogenated organic compound flame retardant such as tetrabromobisphenol A, brominated polycarbonate, decabromo biphenyl ether, etc. with antimony oxide in the composition of the present invention. The present invention will be further explained below with reference to Examples.
In the examples, heat resistance refers to heat distortion temperature ASTMD-
648-56, Izod impact strength is ASTM D-256
−56 Mexhod A and melt viscosity were measured using a high-performance flow tester (manufactured by Shimadzu Corporation) at various resin temperatures.
Measured at 250℃. Further, in the examples, parts indicate parts by weight, and percentages indicate weight %. (1) Polymer containing glutaric anhydride structural unit
Preparation of (A) A monomer consisting of 50 parts of tert-butyl methacrylate, 50 parts of methyl methacrylate, 0.05 part of 2,2'-azobisisobutyronitrile, and 0.2 parts of tert-dodecyl mercaptan was placed in a glass tube at 70°C. The resulting polymer was pulverized and subjected to thermal decomposition reaction in an oil bath at 230°C for 5 hours. The obtained polymer was charged into an extruder and extrusion molded at a resin temperature of 250°C while degassing the generated gas from the exhaust port to form pellets. A glutaric anhydride polymer having the composition shown in Table 1 was obtained in a similar manner.

[Table] (2) Preparation of graft copolymer (B) Graft polymers were obtained by polymerizing various ethylenic monomers in the presence of various rubber polymers. The rubber composition and ethylenic monomer composition are summarized in Table 2. A conventional radical graft reaction was used for the graft polymerization reaction. Regarding B-10, monomers were graft-polymerized in the presence of polybutadiene rubber and the above-mentioned A-3 polymer. The rubber polymer used is as follows. PBd: Polybutadiene rubber (product name Nipol LX-111A, manufactured by Nippon Zeon Co., Ltd.) SBR: Styrene-butadiene rubber (Nippon Zeon Co., Ltd.)
Co., Ltd. product name: SBR-1500) AR: Acrylic rubber (Nippon Zeon Co., Ltd. product name: SBR-1500)
Nipol AR-72) EPDM; Ethylene/propylene/-5-ethylidene-2-norbornene terpolymer rubber manufactured by Mitsubishi Yuka Co., Ltd. Product name EP-43)

[Table] (3) Preparation of copolymer (C) consisting of ethylenic monomer The monomer composition shown in Table 3 was prepared by ordinary radical polymerization.

[Table] Next, the polymers produced as described above were blended as shown in Table 4 and their properties were evaluated. The results obtained are shown in Table 4. As is clear from these results, it can be seen that the resin composition of the present invention has excellent heat resistance, impact resistance, and melt flowability.

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Claims (1)

[Claims] 1. (A) 10 to 95% by weight of a polymer containing glutaric anhydride ring structural units and (B) 5 to 80% by weight of a rubbery polymer containing an ethylenically unsaturated monomer. A thermoplastic resin composition comprising 5 to 90% by weight of a graft copolymer obtained by graft polymerization of 95 to 20% by weight. 2. The thermoplastic resin composition according to claim 1, wherein the content (A) of the polymer containing a glutaric anhydride ring structural unit is 10 to 90% by weight. 3 The polymer (A) has 5 glutaric anhydride ring structural units.
The thermoplastic resin composition according to claim 1 or 2, characterized in that the thermoplastic resin composition contains at least % by weight. 4 (A) 10-95% by weight of a polymer containing a glutaric anhydride ring structural unit (B) 95-20% by weight of an ethylenically unsaturated monomer grafted onto a 5-80% by weight rubbery polymer A thermoplastic resin composition comprising 5 to 90% by weight of a graft copolymer and (C) 85% by weight or less of a polymer or copolymer obtained by polymerizing an ethylenic monomer or a mixture thereof.