JP2573085B2 - Resin composition - Google Patents

Description

The present invention relates to a thermoplastic resin composition having excellent mechanical properties, moldability and appearance of a molded article. More specifically, a thermoplastic resin composition comprising an aromatic polyester resin and a specific maleimide-based copolymer, having improved heat resistance and molding processability of the aromatic polyester resin and providing a molded article having an excellent appearance. About.

[Conventional technology]

Aromatic polyester resin has excellent properties such as mechanical properties, chemical resistance, abrasion resistance, and electrical properties, but has low impact resistance (with notch) and low heat resistance. The molded article has a drawback that defects such as sink marks and warpage tend to occur. In addition, the viscosity of the molten resin is low, so that a drooling phenomenon in which the molten resin flows out from the nozzle of the molding machine to pull the yarn during injection molding is likely to occur, and the molding operation is complicated.

For the purpose of improving such disadvantages of the aromatic polyester resin, attempts have been made to mix or react various polymer substances with the aromatic polyester resin. For example,
For the purpose of improving heat resistance, styrene resins such as styrene-maleimide copolymers have been melt-mixed (Japanese Patent Publication Nos. 51-11976 and 63-12102, and JP-A-54-8775).
No. 1, No. 57-18755, Tokuhei 1-21182, No. 1-27102
), These resins had high heat resistance, but low impact resistance. In order to improve impact resistance, ABS
(Acrylonitrile-butadiene-styrene) resin,
Alternatively, it is modified with epoxy or the like, or further added with an epoxy compound or the like as the third component (Japanese Patent Application Laid-Open No.
54-57563, 60-262847, 61-130366, JP-A-1-123854 and 1-1163249), polyolefin,
Alternatively, it is modified with epoxy or the like, or further added with an epoxy compound or the like as the third component (Japanese Patent Publication No.
57-54058, JP-A-59-184253, JP-A-61-204258,
No. 63-128059, JP-A No. 1-40555, and No. 1-204960
No.), acrylic rubber, or those further containing an epoxy compound or the like as a third component (Japanese Patent Application Laid-Open No. Sho 60-219256, Japanese Patent Publication No. 63-45746). Although sufficiently improved, heat resistance or rigidity was low.

[Problems to be solved by the invention]

As described above, many attempts have been made to improve various characteristics of the aromatic polyester resin, but all of the effects have been practically insufficient.

It is an object of the present invention to provide a polyester resin composition which has good heat resistance and impact resistance, has a good balance of elongation, rigidity and the like, and gives a beautiful appearance.

[Means for solving the problem]

In general, the present invention relates to a resin composition, wherein (A) 30 to 70 mol% of an aromatic vinyl monomer group, 25 to 50 mol% of a maleimide monomer group, and an unsaturated dicarboxylic acid. 10 to 50% by weight of a maleimide copolymer comprising 3 to 30% by mole of an acid anhydride monomer group and 0 to 50% by mole of another copolymerizable monomer group;
80% by weight and (C) an epoxy group-containing vinyl monomer having an epoxy group content of 0.1 to 10 parts by weight based on 100 parts by weight of ethylene, vinyl carboxylate and acrylate. Group-containing acrylic acid copolymer 3
-40% by weight as an active ingredient.

The present inventors, the thermoplastic resin composition according to the present invention,
It has been found that a good balance of impact resistance, elongation, rigidity, heat resistance, etc., excellent moldability, and that the molded article gives a beautiful appearance.

The method for producing the maleimide-based copolymer used in the present invention is not particularly limited. For example, an aromatic vinyl monomer, a maleimide-based monomer, an unsaturated dicarboxylic anhydride monomer, and if necessary, other copolymers. It could be produced by radical copolymerization of polymerizable monomers.

Specific examples of the aromatic vinyl monomer include styrene, α
-Methylstyrene, vinyltoluene, t-butylstyrene and the like, and specific examples of the maleimide-based monomer include maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-hexylmaleimide, N- Cyclohexylmaleimide, N-phenylmaleimide, N-tolylmaleimide and the like, specific examples of unsaturated dicarboxylic anhydride monomers include maleic anhydride, methylmaleic anhydride, 1,2-dimethylmaleic anhydride, Examples include ethyl maleic acid and phenyl maleic anhydride, and specific examples of other copolymerizable monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and hexyl (meth) acrylate. , Cyclohexyl (meth) acrylate, decyl (meth) Rate, octadecyl (meth) acrylate, hydroxyethyl (meth) acrylate, methoxyethyl (meth) acrylate, there are glycidyl (meth) acrylate, and these can be used alone or in combination. Here, methyl (meth) acrylate means methyl acrylate or methyl methacrylate.

The method for copolymerizing these monomers is not particularly limited, and any known radical copolymerization method can be used.

Another method for producing the maleimide-based copolymer used in the present invention includes copolymerization of an aromatic vinyl monomer, an unsaturated dicarboxylic anhydride monomer and, if necessary, other copolymerizable monomers. A method of reacting the union with ammonia or a primary amine to imidize an acid anhydride group can be exemplified. The imidation reaction between a polymer having an acid anhydride group in a polymer chain and an amine compound is known.For example, according to the methods disclosed in JP-B-61-26936 or JP-B-62-8456. By reacting a polymer substance with an amine compound, a maleimide-based copolymer having a target imide group can be produced.

Examples of the primary amine used in the imidation reaction include methylamine, ethylamine, propylamine, butylamine, hexylamine, cyclohexylamine,
Decylamine, aniline, toluidine, naphthylamine, chlorophenylamine, dichlorophenylamine,
Bromophenylamine, dibromopheninamine and the like.

The imidization reaction is carried out in a solution state using an autoclave,
The reaction can be performed in a bulk molten state or a suspended state. It is also possible to carry out the reaction in a molten state using a melt kneading device such as a screw extruder.

The solvent used in the solution reaction is arbitrary, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, ketones such as cyclohexanone, tetrahydrofuran, ethers such as 1,4-dioxane, toluene, aromatic hydrocarbons such as xylene, dimethyl Examples include formamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, and the like.

The reaction temperature for imidization is preferably in the range of 50 to 350 ° C.,
A range from 00 to 300 ° C. is particularly preferred.

The imidation reaction does not necessarily require the presence of a catalyst, but if used, trimethylamine, triethylamine, tributylamine, N, N-dimethylaniline, N, N-
Tertiary amines such as diethylaniline are preferred.

The maleimide-based copolymer used in the present invention contains 30 to 70 mol% of an aromatic vinyl monomer group and 25% of a maleimide-based monomer group.
~ 50 mol%, unsaturated dicarboxylic anhydride monomer group 3 ~ 30
Mole% and other copolymerizable monomer groups 0 to 50 mole%
Consists of If the amount of the aromatic vinyl monomer group is less than 30 mol%,
It is difficult to produce a polymer having a homogeneous composition industrially with good reproducibility, and the thermal stability and moldability of the composition obtained by mixing the maleimide-based copolymer with an aromatic polyester resin Inferior properties such as mechanical strength. When the content of the aromatic vinyl monomer group exceeds 70 mol% or the content of the maleimide monomer group is less than 25 mol%, the heat resistance of the obtained composition is poor and the maleimide monomer group is poor. Exceeds 50 mol%, the molding processability of the obtained composition is inferior. When the content of the unsaturated dicarboxylic anhydride monomer group is less than 3 mol%, the compatibility of the composition obtained by mixing with the aromatic polyester resin is poor, and the mechanical strength is poor. A peeling phenomenon is observed in the molded product. On the other hand, when the amount of the unsaturated dicarboxylic anhydride monomer group exceeds 30 mol%, the molding processability of the composition is poor, and the thermal stability of the molded product is poor.

The aromatic polyester resin used in the present invention is mainly composed of an aromatic dicarboxylic acid or a derivative thereof and an aliphatic glycol or a derivative thereof, and is a polymer or a copolymer obtained by a condensation reaction, and specific examples will be given. And a polyester containing an aromatic ring such as polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, polypentamethylene terephthalate, polyhexamethylene terephthalate, polydecamethylene terephthalate, and these alone.
Alternatively, they can be used in combination.

In the present invention, a composition is prepared by mixing 10 to 50% by weight of a maleimide-based copolymer, 40 to 80% by weight of an aromatic polyester resin, and 3 to 40% by weight of an acrylate-based copolymer containing an epoxy group. When the maleimide-based copolymer is less than 10% by weight or the aromatic polyester resin exceeds 80% by weight,
The degree of improvement in the heat resistance and molding processability of the obtained composition is insufficient, and if the amount of the maleimide-based copolymer exceeds 50% by weight or the amount of the aromatic polyester resin is less than 40% by weight, the composition may be insufficient. Poor mechanical strength, chemical resistance or abrasion resistance.

On the other hand, if the epoxy group-containing acrylate copolymer is less than 3% by weight, the effect of improving the impact resistance is low, and if it exceeds 40% by weight, the decrease in rigidity is too large.

The epoxy group-containing acrylate copolymer is
Ethylene and vinyl carboxylate and acrylate;
It is a copolymer with a vinyl monomer containing an epoxy group. Specific examples of the vinyl carboxylate used include vinyl acetate and vinyl propionate, and specific examples of the acrylate include methyl acrylate. , Ethyl acrylate, propyl acrylate, n-butyl acrylate,
There are 2-ethylhexyl acrylate, methoxymethyl acrylate, methoxyethyl acrylate, ethoxymethyl acrylate, and ethoxyethyl acrylate.

The amount of the epoxy group-containing vinyl monomer in the epoxy group-containing acrylate copolymer is 0.1 to 10 parts by weight in total with respect to 100 parts by weight in total of ethylene, vinyl carboxylate and acrylate. Preferably, if less than 0.1 part by weight, the mechanical strength of the obtained composition is insufficient, a layered peeling phenomenon may be observed in the molded product, and if it exceeds 10 parts by weight, the mechanical strength Alternatively, thermal stability may be impaired. According to the findings of the present inventors, when the same amount of the same aromatic polyester resin is used, the one that is particularly important as a factor that determines the dispersed particle size of the composition is an unsaturated polymer in the maleimide-based copolymer. It is the content of the dicarboxylic anhydride monomer group. When the content is low, the particle size is large, and when the content is high, the particle size is small. Further, the content of the epoxy group in the epoxy group-containing acrylate copolymer is also important, and exhibits the same effect as the unsaturated dicarboxylic anhydride monomer group in the maleimide copolymer.

As another factor, the dispersion particle diameter also depends on the method of mixing the maleimide-based copolymer with the aromatic polyester resin and the epoxy group-containing acrylate-based copolymer.

The mixture of a maleimide copolymer and an aromatic polyester resin, an epoxy group-containing acrylate copolymer,
The melt kneading can be carried out using a usual melt kneading apparatus, and examples of suitable melt kneading apparatuses include a screw extruder, a Banbury mixer, a co-kneader, and a mixing roll.

The composition of the present invention can be made into a composition by adding other additives or modifiers depending on the application.Specifically, glass fibers, carbon fibers, reinforcing fibers such as aramid fibers, There are fillers such as talc, silica, clay, mica, calcium carbonate, etc., ultraviolet absorbers, flame retardants, lubricants, coloring agents and the like.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples, but all parts and percentages used in Examples and Comparative Examples are by weight. These are all examples and do not limit the content of the present invention.

 In addition, the measuring method of various properties is as follows.

Heat resistance: Heat distortion temperature (HDT) was measured under a load of 18.6 kg / cm ² using an injection molded product having a thickness of 1/4 ″ according to ASTM D-648. (No annealing) Impact strength: ASTM D- According to 256, a notched Izod was measured using an injection molded product having a thickness of 1/4 ″. The ambient temperature is 23 ° C.

Fluidity: 265 ° C, load 10 according to ASTM D-1238
The melt flow rate was measured in kg.

Appearance: A molded article having a boss and a rib on the back surface and having an opening was molded with a 5-ounce injection molding machine, and the appearance of the molded article was visually judged. The molding temperature is 270 ° C.

Elongation: Measured according to ASTM D-638 using an injection molded product having a thickness of 1/8 ″.

Rigidity: According to ASTM D-790, a flexural modulus was measured using an injection molded product having a thickness of 1/4 ″.

(1) Maleimide-based copolymer (A) The maleimide-based copolymer was prepared by charging 100 parts of styrene into an autoclave equipped with a stirrer, replacing the system with nitrogen gas, and then heating to 80 ° C. To this, a solution prepared by melting 67 parts of maleic anhydride and 0.2 parts of benzoyl peroxide in 300 parts of methyl ethyl ketone was added in 8 hours.
After the addition, the temperature was kept at 80 ° C. for a further 4 hours.

1.2 parts of triethylamine and 44 parts of aniline were added to the above copolymer, and reacted at 130 ° C. for 7 hours. The reaction solution was cooled to room temperature, and vigorously stirred methanol 30.
0 parts, filtered and dried to obtain a maleimide-based copolymer (a
-2) was obtained. Other maleimide-based copolymers were similarly prepared. These are shown in Table 1.

(2) Aromatic polyester resin (B) A standard PBT resin (b-1) which is generally commercially available.

(3) Epoxy group-containing acrylate copolymer (C) Ethylene 5% by weight, vinyl acetate 15% by weight, n-butyl acrylate 80% by weight, glycidyl methacrylate 0 part (c-1), 1.0 part ( c-2), 1.5 parts (c-3), 2.0
A copolymer consisting of a part (C-4).

Examples-1 to 11 and Comparative Examples-1 to 5 1.0 kg of the maleimide-based copolymer, 2.2 kg of the aromatic polyester resin, and 0.8 kg of the epoxy group-containing acrylate-based copolymer were put into a 20-liter Henschel. After blending, use a TEM35B extruder (Toshiba, 2-axis same direction)
Extruded and pelletized at ℃. Using the pellets, test specimens for measuring physical properties were prepared by an injection molding machine, and various physical properties and the like were measured. The results are shown in Tables 2 and 3. Similarly, Examples 2 to 11 and Comparative Examples 1 to 5 were performed. In Comparative Examples -1 and 2, the maleic anhydride content in the maleimide-based copolymer was out of the range. In Comparative Example-3, the epoxy group content in the epoxy group-containing acrylate copolymer was out of the range.
In Comparative Examples-4 and 5, the content of the epoxy group-containing acrylate-based copolymer was out of the range.

The molding temperature was set at 270 ° C. as a standard, and a slight correction was made depending on the state of the molded product.

The following is clear from the results of the examples and comparative examples.

From Example 2 and Comparative Example 1, if the maleimide-based copolymer does not have an unsaturated dicarboxylic anhydride monomer group, the effect of improving the impact value is small, the elongation is low, and it is not practical.

Further, even if the amount of the unsaturated dicarboxylic anhydride is too large as in Comparative Example-2, the impact value is not improved, resulting in poor appearance and lowering of moldability (flow).

From Example-2 and Comparative Example-3, the content of the epoxy group in the epoxy group-containing acrylate-based copolymer is important, and if not contained, the effect of improving the impact value is small and the appearance is poor. You can see that.

As described above, it can be seen that only when both contain an appropriate unsaturated dicarboxylic anhydride and an epoxy group, the physical property balance is improved.

〔The invention's effect〕

The resin composition of the present invention has good heat resistance and impact resistance,
It has a good balance of elongation, rigidity, etc., and has a beautiful appearance of the molded product, and has extremely high practical value as a material for various industrial parts.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 31/00 LHJ C08L 31/00 LHJ 33/08 LJD 33/08 LJD LJE LJE 35/06 LHS 35 / 06 LHS LJW LJW 67/02 LNZ 67/02 LNZ LPB LPB

Claims (1)

(57) [Claims] (A) 30 to 70 mol% of an aromatic vinyl monomer group, 25 to 50 mol% of a maleimide monomer group, 3 to 30 mol% of an unsaturated dicarboxylic anhydride monomer group, and others. 10 to 50% by weight of a maleimide copolymer comprising 0 to 50 mol% of a copolymerizable monomer group of (B) an aromatic polyester resin 40 to
80% by weight and (C) an epoxy group-containing vinyl monomer having an epoxy group content of 0.1 to 10 parts by weight based on 100 parts by weight of ethylene, vinyl carboxylate and acrylate. A thermoplastic resin composition comprising 3 to 40% by weight of a group-containing acrylate copolymer as an active ingredient.