JPH0517935B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermoplastic resin composition that is excellent in heat resistance, impact resistance, and weather resistance in a well-balanced manner. Polyglutarimide is a resin with a high heat distortion temperature, but on the other hand, it has poor mechanical properties such as impact strength, so its use as a thermoplastic resin has been limited. A method for modifying polyglutarimide resin intended for thermoplastic molding materials is disclosed in JP-A-52-
As described in Publication No. 63989, the impact of acrylonitrile/butadiene/styrene (ABS) copolymers, methyl methacrylate/butadiene/styrene (MBS) copolymers, or alkyl acrylate rubbers such as polybutyl acrylate Although methods of mixing modifiers are known, it is difficult to obtain sufficiently high impact strength simply by mixing these impact modifiers. In addition, impact modifiers based on diene rubbers such as ABS copolymers and MBS copolymers contain double bonds in the rubber, so they are susceptible to deterioration due to oxygen, ozone, ultraviolet rays, etc. Even if the impact strength of the polyglutarimide resin is increased by mixing these impact modifiers, it is not possible to obtain an impact resistant resin with excellent weather resistance. On the other hand, since acrylic rubber such as polybutyl acrylate rubber does not contain unsaturated bonds, it is expected that a polyglutarimide resin composition with excellent weather resistance can be obtained by mixing it as an impact modifier. The impact strength of the resulting resin composition is insufficient, and its practical value as a heat-resistant and impact-resistant resin is low. In order to impart impact resistance and weather resistance to polyglutarimide, the present inventors first applied an aromatic compound to polyglutarimide in the presence of an ethylene-propylene-nonconjugated diene copolymer rubber. Graft copolymer ( We proposed a method of blending AES graft copolymer (hereinafter abbreviated as AES graft copolymer). This method has made it possible to produce a polyglutarimide resin composition with excellent weather resistance and impact resistance; however, this method requires (1)
The production of AES graft copolymers requires complicated polymerization processes such as bulk polymerization and solution polymerization, and (2) in order to obtain high impact strength, it is necessary to increase the amount of AES graft copolymer. As a result, the heat distortion temperature of the composition is lowered, so that it is difficult to achieve a sufficiently satisfactory balance between impact strength and heat distortion temperature, so there is still room for improvement. Therefore, the present inventors conducted further intensive studies with the aim of improving the above points, and as a result, they decided to blend modified polyethylene, which is a copolymerization of α,β-unsaturated carboxylic acid glycidyl ester with polyglutarimide. Therefore, it was discovered that a resin composition with excellent balance in heat distortion temperature, impact strength, and weather resistance could be obtained, and the present invention was achieved. That is, the present invention comprises (A) polyglutarimide and
(B) Modified polyethylene obtained by copolymerizing 0.1 to 30% by weight of at least one α,β-unsaturated carboxylic acid glycidyl ester with respect to ethylene (A)
A thermoplastic resin composition is provided in which 99 parts by weight and (B) are mixed in a ratio of 70 to 1 part by weight, such that the total of (A) and (B) is 100 parts by weight. Although the reason why the effects of the present invention are produced is unclear, there is a chemical bond between the glycidyl group contained in modified polyethylene and the carboxyl group or acid anhydride group that is estimated to be contained in a trace amount in polyglutarimide. This is presumed to be because the compatibility of both components is significantly improved. The thermoplastic resin composition of the present invention is obtained by mixing predetermined amounts of polyglutarimide (A) and specific modified polyethylene (B). The polyglutarimide (A) used in the present invention is a polymer or copolymer containing a cyclic imide unit represented by the following formula (). However, R ₁ , R ₂ and R ₃ in the formula each represent hydrogen or a substituted or unsubstituted alkyl group or aryl group having 1 to 20 carbon atoms. Any polyglutarimide having any chemical structure can be applied to the present invention as long as it contains the above cyclic imide unit, but usually R ₁ and
Those in which R ₂ is hydrogen or a methyl group and R ₃ is hydrogen, a methyl group, an ethyl group, a propyl group, a butyl group, or a phenyl group are generally used. The method for producing polyglutarimide is not particularly limited, but for example, as described in JP-A-52-63989 and JP-A-58-71928,
A useful method is to react a (meth)acrylic acid polymer such as polymethyl methacrylate or polyglutaric anhydride with ammonia or a primary amine such as methylamine, ethylamine or aniline in an extruder to form a glutarimide ring. It is. On the other hand, modified polyethylene (B) used in the present invention
is a glycidyl group-containing ethylene copolymer obtained by copolymerizing 0.1 to 30% by weight of α,β-unsaturated carboxylic acid glycidyl ester with respect to ethylene. Here, α,β-unsaturated carboxylic acid glycidyl ester 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 copolymerization amount of α,β-unsaturated carboxylic acid glycidyl ester in modified polyethylene (B) is
A range of 0.1 to 30% by weight, especially 0.5 to 20% by weight is appropriate; if it is less than 0.1% by weight, sufficient affinity with polyglutarimide (A) cannot be exhibited;
The above is not preferable because the flexibility of the modified polyethylene itself is impaired and a composition with excellent mechanical properties cannot be obtained. The modified polyethylene (B) also contains a small proportion of other copolymerizable unsaturated monomers, such as propylene, 1
-α-olefins such as butene, vinyl ethers, vinyl esters such as vinyl acetate and vinyl propionate, acrylic acid and methacrylic acid esters such as methyl, ethyl, propyl, and butyl, acrylonitrile, styrene, carbon monoxide, etc. One or more types may be copolymerized. Specific examples of modified polyethylene (B) include ethylene/glycidyl methacrylate copolymer, ethylene/vinyl acetate/glycidyl methacrylate copolymer, ethylene/carbon monoxide/glycidyl methacrylate copolymer, and ethylene/glycidyl acrylate copolymer. Examples include polymers, ethylene/glycidyl acrylate/vinyl acetate copolymers, and these can be produced by known methods. The blending ratio of polyglutarimide (A) and modified polyethylene (B) is (A) 30 to 99 parts by weight, preferably 50 to 95 parts by weight, and (B) 70 to 1 part by weight, preferably 50 to 5 parts by weight. , and the total of (A) and (B) is 100 parts by weight. Within this composition range, it is possible to obtain a resin composition with excellent balance in heat distortion temperature, impact strength, and weather resistance. The blending ratio can be appropriately selected within this range depending on the purpose and use, and can be set to a desired balance of physical properties. For example, modified polyethylene (B) is used for applications that require relatively high rigidity.
On the other hand, for applications where flexibility and toughness are particularly required, a high proportion of modified polyethylene (B) may be mixed. In addition to polyglutarimide (A) and modified polyethylene (B), the resin composition of the present invention may optionally contain polystyrene (PS), styrene/acrylonitrile copolymer (SAN), and polymethyl methacrylate (PMMA). , styrene/methacrylic acid/acrylonitrile copolymer, α-methylstyrene/acrylonitrile copolymer, α-methylstyrene/
Vinyl polymers such as styrene/acrylonitrile copolymer, α-methylstyrene/methyl methacrylate/acrylonitrile copolymer, p-methylstyrene/acrylonitrile copolymer, and t-butylstyrene/acrylonitrile copolymer are appropriately mixed. polyethylene, polypropylene,
Ethylene/propylene copolymer, ethylene/butene-1 copolymer, ethylene/propylene/dicyclopentadiene copolymer, ethylene/propylene/5-ethylidene-2-norbornene copolymer, ethylene/propylene/1,4- By appropriately mixing polyolefin rubbers such as hexadiene copolymer, ethylene/vinyl acetate copolymer, ethylene/propylene/vinyl acetate copolymer, and ethylene/butyl acrylate copolymer,
Furthermore, it is also possible to adjust the physical properties and characteristics to desired ones. Furthermore, by adding at least one selected from organic sulfonates and sulfate ester salts to the thermoplastic resin composition of the present invention, it is possible to obtain a composition with further improved impact resistance and weather resistance. I can do it. The organic sulfonate and sulfuric acid ester salt mentioned here have the general formula R(SO ₃ M)
_o and R(OSO ₃ M) _o . 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. R
Preferred examples include phenyl, α-naphthyl,
Examples include 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 15-naphthalenedisulfonate, naphthalenesulfonic acid formalin condensate, sodium salt of sulfonated polystyrene, etc. Preferred examples of sulfuric ester salts include potassium lauryl sulfate, stearyl sulfate. These include calcium, 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. These organic sulfones The amount of the acid salt 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 1 part by weight, undesirable phenomena such as worsening of the color tone of the composition will occur. There are no particular limitations on the method for producing the thermoplastic resin composition of the present invention, and generally known methods can be employed. That is, polyglutarimide (A)
and modified polyethylene (B) in the form of pellets, powder, or small pieces using a high-speed stirrer, etc., and then melt-kneaded using a single-screw or multi-screw extruder with sufficient kneading capacity. Methods such as melt kneading using a mixer or rubber roll machine, etc.
Various methods can be adopted. The resin composition of the present invention can be further mixed with other polymers and resins to adjust the desired performance as long as the physical properties are not impaired. for example
ABS resin, MBS resin, acrylonitrile
EPDM-styrene terpolymer (AES) resin,
Polycarbonate, polyamide, polybutylene terephthalate, polyethylene terephthalate, and the like may be mixed. Depending on the purpose, reinforcing materials and fillers such as pigments and dyes, glass fibers, metal fibers, metal flakes, and carbon fibers, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, lubricants, plasticizers,
Antistatic agents, flame retardants, etc. can be added. The present invention will be further explained below using reference examples, working examples, and comparative examples. In the Examples, Reference Examples, and Comparative Examples, the heat distortion temperature was measured in accordance with ASTM D-648, and the Izod impact strength was measured in accordance with ASTM D-256-56, Method A. Weather resistance was evaluated by measuring changes in Izotz impact strength after 100 hours of irradiation using a Sunshine Weatherometer. Parts represent parts by weight, and % represents weight %. Reference example (Preparation of polyglutarimide (A)) Pellets of polymethyl methacrylate are charged into an extruder together with ammonia, methylamine, or aniline, and while the generated gas is degassed from the exhaust port attached to the extruder, the resin is Three types of polyglutarimides shown in Table 1 were prepared by extrusion at a temperature of 280°C.

[Table] Example 1 Polyglutarimide (A-
1) to (A-3), the following modified polyethylenes (B-1) to (B-3) and additives were mixed at the blending ratio shown in Table 2, and melt extruded at 260°C.
The pellets were formed into pellets and then molded into test pieces for measuring physical properties using an injection molding machine at a cylinder temperature of 260°C and a mold temperature of 80°C, and various measurements were performed. Modified polyethylene (B) B-1: Ethylene/glycidyl methacrylate =
90/10 (%) Copolymer B-2: Ethylene/glycidyl methacrylate/vinyl acetate = 90/2/8 (%) Copolymer B-3: Ethylene/glycidyl methacrylate/methyl acrylate = 80/15 /5 (%) Copolymer additive SDBS: Sodium dodecylbenzenesulfonate LSN: Sodium lauryl sulfate The physical property measurement results are shown in Table 2. The Izot impact strength is shown as measured values (a) before irradiation with a Sunshine Weatherometer and (b) after 100 hours of irradiation. Comparative example Polyglutarimide shown in Table 1, polymethyl methacrylate (PMMA), the above modified polyethylene
(B), additives and the following rubbery polymers (C-
1) and (C-2) were mixed at the blending ratio shown in Table 2,
Each physical property was measured in the same manner as in Example 1. The measurement results are shown in Table 2. Rubber-like polymer (C) C-1: Mitsui EPT#4070 manufactured by Mitsui Petrochemical Industries, Ltd.
(Iodine number: 24, Mooney viscosity: 65, non-conjugated diene component: ethylene-propylene-non-conjugated diene terpolymer rubber of 5-ethylidene-2-norbornene) C-2: Ethylene/butene = 90/10 ( weight%) copolymer rubber

[Table] The following is clear from the results of Example 1 and Comparative Example. The resin compositions (Nos. 1 to 11) of the present invention have extremely high heat distortion temperatures and excellent impact strength. Furthermore, even after 100 hours of irradiation with a weatherometer, there is almost no decrease in impact strength, and it is also weather resistant. On the other hand, when non-imidized polymethyl methacrylate is used instead of polyglutarimide (Nos. 12 to 14), even if modified polyethylene is mixed, not only the heat distortion temperature is inferior but also the impact strength is poor. Not expressed. In addition, even if polyglutarimide is mixed with ordinary polyolefin rubber that does not have glycidyl groups, impact strength is not developed (No. 15 to
20). Example 2 Using rubbery polymers (C-1) and (C-2) in addition to polyglutarimide (A) and modified polyethylene (B),
They were mixed at the blending ratio shown in Table 2, and their physical properties were measured in the same manner as in Example 1. The results are shown in Table 2. It is clear that even when other polyolefin rubbers are used in combination, a resin composition with excellent heat distortion temperature, impact strength, and weather resistance can be obtained. As explained above, the resin composition of the present invention is excellent in heat distortion temperature, impact strength, and weather resistance in a well-balanced manner. Moreover, since each resin component can be manufactured simply by melting and kneading, productivity is extremely high. Taking advantage of these features, it is expected that it will be applied to various uses in the future.

Claims (1)

[Claims] 1 Modified polyethylene obtained by copolymerizing (A) polyglutarimide and (B) ethylene with at least 0.1 to 30% by weight of at least one α,β-unsaturated carboxylic acid glycidyl ester, A thermoplastic resin composition obtained by mixing 99 parts by weight and 70 to 1 part by weight of (B) in a ratio such that the total of (A) and (B) is 100 parts by weight.