JPH01138261A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which can give a molding excellent in surface appearance and impact resistance, by mixing an aromatic polyester with a butadiene graft copolymer and a specified multiphase structure polymer. CONSTITUTION:40-98wt.% aromatic polyester (A) which is a polyester having aromatic rings in the main chain of the polymer, such as polybutylene terephthalate, is mixed with 1-30wt.% butadiene graft copolymer (B) prepared by grafting at least one vinyl monomer selected from among a methacrylic ester (b), an aromatic monovinyl compound (c) and a vinyl cyanide (d) onto 10-85wt.% butadiene polymer (a) of a butadiene component content >=50wt.% to a degree of grafting of 15-200% and 1-30wt.% multi-phase structure polymer (C) prepared by grafting at least one member selected among an acrylic ester (g), component (b) and component (c) a copolymer (e) of an alpha-olefin with 0.5-40wt.% alpha,beta-unsaturated acid glycidyl ester (f).

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a resin composition, and more specifically, a thermoplastic resin composition that has excellent surface appearance, moldability, and mechanical properties, particularly impact properties. Regarding.

[Prior Art] Aromatic polyester is generally a thermoplastic material that has various excellent properties including oxidation resistance and machinability.
It has good physical and mechanical properties when melt molded and is suitable for making fibers, films, or general molded products. However, this small aggregate has a drawback in that the impact resistance when formed into a molded article is inferior to that of borino j-bonate and polyphenylene ether, which are non-grade resins.

As a method of improving the impact resistance of aromatic polyester, a method of blending an olefin copolymer has been proposed (Japanese Patent Publication No. 58-47419).

In this case, although it is effective for improving impact resistance, especially low-temperature impact properties, the aromatic polyester and olefin copolymer are incompatible in this resin composition, so the resulting molded product exhibits layer delamination. Another problem is that it tends to cause striped patterns on the surface, making it impossible to obtain a product with a good appearance.

[Object of the Invention] The object of the present invention is to provide a new resin composition that has excellent surface appearance and good mechanical properties, particularly low-temperature impact properties and moldability.

[Configuration 1 of the Invention The present invention comprises (A>40 to 98% by weight of aromatic polyester, and (B)
Methacrylic acid ester (
0), a 1-30-polybutadiene-based graft copolymer obtained by graft copolymerizing one or more vinyl-based monocamellia selected from the group consisting of aromatic monovinyl compounds (c) and vinyl cyanide compounds (d) (C) At least one member selected from the group of acrylic esters, methacrylic esters and aromatic monovinyl compounds is added to a copolymer consisting of an α-olefin and a glycidyl ester of an α,β-unsaturated acid. This is a thermoplastic resin composition comprising 1 to 30% by weight of a graft copolymerized multiphase polymer.

The aromatic polyester used in the present invention (A> aromatic polyester is a polyester having an aromatic ring in the main chain of the polymer, and mainly contains an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. It is a polymer or copolymer obtained by a condensation reaction using the aromatic dicarboxylic acid as a component.For example, terephthalic acid is used as the aromatic dicarboxylic acid component.

Dicarboxylic acids with benzene nuclei such as isophthalic acid,
naphthalene-2,6-dicarboxylic acid, naphthalene-1,
Examples include dicarboxylic acids having a naphthalene nucleus such as 5-dicarboxylic acid and naphthalene-2,7-dicarboxylic acid, or ester-forming derivatives thereof.

Instead of such aromatic dicarboxylic acids or ester-forming derivatives thereof, dicarboxylic acids other than aromatic dicarboxylic acids, such as adipic acid, sebacic acid, or ester-forming derivatives thereof, may be used in an amount of 20 mol% or less of the acid component. can. Examples of diol components include ethylene glycol 2-tetramethylene glycol and hexamethylene glycol.

Examples include aliphatic glycols such as diethylene glycol and cyclohexane dimetatool, diols having an aromatic ring such as 1,4-bisoxyethoxybenzene and bisphenol A, and ester-forming derivatives thereof.

As the aromatic polyester, polybutylene terephthalate is particularly preferred.

The butadiene-based graft copolymer (B) used in the present invention is a butadiene-based polymer (a) containing methacrylic acid (b).
, an aromatic monovinyl compound (c), and a vinyl cyanide compound (d). In this graft covalent union, butadiene-based polymer (a)
The amount of is 10 to 85% by weight, especially 30 to 70% by weight
It is preferable that If it is less than 10Φm%,
The impact strength of the resulting resin composition is low, while 85%
If the amount is more, the moldability of the resulting resin composition will deteriorate, which is not preferable. As the butadiene polymer (a), a copolymer of a butadiene monomer and a vinyl monomer, such as styrene, can also be used, but in terms of impact resistance, the butadiene component is It is preferable that it is 50% or more.

The vinyl monomers to be graft copolymerized to the butadiene polymer (a) include methacrylic acid ester (01), aromatic monovinyl compound (/su) and cyanide vinyl compound (-4).
The vinyl monomers may be used in any ratio, and a small proportion thereof may be replaced with other vinyl monomers. Further, the order in which the vinyl monomers are used in graft copolymerization is arbitrary, and two or more types may be used simultaneously, or they may be used separately in graft copolymerization without any problem.

As the methacrylic ester, alkyl esters having 1 to 4 carbon atoms are preferred, and methyl esters are particularly preferred. Examples of the aromatic monovinyl compound include styrene, vinyltoluene, α-methylethylene, nuclear halogenated styrene, and vinylnaphthalene, with styrene being particularly preferred. Examples of vinyl cyanide compounds include acrylonitrile.

Examples include methacrylonitrile and α-halogenated acrylonitrile, with acrylonitrile being particularly preferred. As the butadiene-based graft copolymer, ABS and MBS are preferably used.

In addition, butadiene-based graft copolymers are resistant! From the viewpoint of impact resistance and surface appearance, the grafting ratio is preferably 15 to 200%. Here, the graft ratio is a value calculated from the following formula.

Grafting ratio = weight of acetone insoluble matter / weight of rubber component [component (a)] x 100 However, in the formula, ahiton insoluble matter is determined by thoroughly immersing the graft copolymer in acetone and then thoroughly removing the insoluble precipitate by centrifugation. Collect and find it.

The butadiene-based graft copolymer used in the present invention is
It can be produced by any method including bulk polymerization, suspension polymerization, bulk suspension polymerization, solution polymerization, or emulsion polymerization. In particular, when producing components with a high rubber content, it is desirable to perform Hu by emulsion graft polymerization.

The butadiene-based graft copolymer of the present invention may be used in combination with a hard thermoplastic resin, but the butadiene-based polymer component (a) is It is necessary that the ratio is 10% or more. As the hard thermoplastic resin, either one obtained by polymerizing the same vinyl monomer as the vinyl monomer used in the graft copolymer or a thermoplastic resin obtained from a different monomer can be used. However, from the viewpoint of compatibility, those obtained from the same monomer are preferred.

α- in the (C) multilayer structure polymer used in the present invention
Olefins are ethylene and propylene.

Butene-1, etc., and ethylene is particularly preferred.

In addition, the glycidyl ester of an α,β-unsaturated acid is a compound represented by the general formula (in which R is a hydrogen atom, a lower alkyl group, or a lower alkyl group substituted with a glycidyl ester group). Glycidyl acrylate and glycidyl methacrylate.

These include glycidyl itaconate, and glycidyl methacrylate is particularly preferred. The copolymerization ratio of the glycidyl ester of α,β-unsaturated acid in the glycidyl group-containing copolymer is preferably 0.5 to 40% by weight, more preferably 1 to 30% by weight, and preferably 2 to 20% by weight. It is in the range of 1%.

As the acrylic ester and methacrylic ester as the graft component, an alkyl ester having 1 to 4 carbon atoms is preferable, and as the aromatic monovinyl compound, styrene is preferable.

As a method for obtaining a graft copolymerized multiphase structure polymer, a polymerizable heptamer having a peroxide bond and graphs 1 to 1 above are used.
By copolymerizing the components to obtain a block polymer with peroxide bonds in the side chains, it is then melted and kneaded in a kneader with a copolymer consisting of an α-olefin and a glycidyl ester of an α,β-unsaturated acid. You can get what you want.

The resin composition obtained by blending (A) aromatic polyester with (B) butadiene-based graft copolymer and (C) multilayer structure polymer has no delamination, has excellent surface appearance, and has high impact resistance. Excellent molded products can be molded. The reason for this is not clear, but it is speculated that the graft component of the multiphase structure polymer is compatible with the graft component of the (B) butadiene-based graft copolymer, and the glycidyl group of the component (C) and the aromatic polyester It is thought that the chemical bonding between the terminal carboxyl group of the component (A) and the component (B) improves the interfacial adhesion and compatibility between the component (A) and the component (B), thereby imparting properties.

The mixing ratio of such thermoplastic resin composition is as follows:
Component (A) is 40 to 98% by weight, component (B) is 1 to 30% by weight (preferably 3 to 20% by weight), and component (C) is 1 to 30% by weight (preferably 3 to 20% by weight). (
If the content of component A) is 40% by weight, the resulting composition will have insufficient heat resistance, while if the content of component (A) exceeds 98% by weight, the impact resistance will be insufficient. becomes.

When the content of component (B) is 1% by weight, the resistance of the resulting composition is 1! If it exceeds 30% by weight, the impact resistance and surface appearance are not improved, and the heat resistance of the composition decreases, which is undesirable. If the content of component (C) is less than 1% by weight, the impact strength of the resulting composition will not be improved;
On the other hand, if it exceeds 30% by weight, not only the heat resistance of the resin composition decreases, but also the surface appearance is impaired even in the presence of component (B), which is not preferable.

In addition, various additives (for example, fibrous reinforcing agents, stabilizers, pigments, fi refueling agents, mold release agents, inorganic fillers) may be added to the resin composition of the present invention within a range that does not impair the purpose of the present invention. can be included.

The thermoplastic resin composition of the present invention can be prepared by any method of mixing solid substances (for example, using a Banbury mixer).
A method using a single heated roll, a single screw extruder, or a multi-screw extruder) can be applied.

[Example] The effects of the present invention will be explained in further detail with reference to Examples below.

In addition, "1 part" and "%" in the examples are all based on vehicle standards, and lllrIJ strength is determined according to the method of ASTM-256.
The surface appearance was evaluated by the striped pattern and gloss of the surface.

Further, the reduced specific viscosity is a value measured at 35° C. by dissolving 1.2 gr of the polymer in 100% orthochlorophenol.

Examples 1 to 5 and Comparative Examples 1 to 6 Polybutylene terephthalate (reduced specific viscosity 1.10) dried at 130°C for 5 hours as aromatic polyester,
A butadiene-based graft copolymer obtained by emulsion graft copolymerization of 24 parts of methyl methacrylate and 16 parts of styrene in the presence of 60 parts of butadiene-styrene copolymer rubber (graft ratio: 57
．． 3%), 70 parts of ethylene-glycidyl methacrylate copolymer rubber and 30 parts of polymethyl methacrylate having a peroxide bond were extruded 11 (cylinder temperature 200°C).
It was extruded and pelletized. The multiphase structural polymers were uniformly mixed in various proportions shown in Table 1 using a V-type blender.

The resulting mixture was melt-kneaded in a 44 m + diameter twin-screw extruder at a barrel temperature of 250° C., and the thread discharged from the die was cooled and cut to obtain pellets for molding.

Next, the pellets were dried with hot air at 130°C for 5 hours, and then a test piece mold for measuring physical properties was attached to a 5-ounce injection molding machine, and the cylinder temperature was set at 260°C.

The test pieces were molded under the molding conditions of a mold temperature of 90°C, an injection pressure cuff of 00 Kg/cIi, a cooling time of 20 seconds, and a total cycle of 35 seconds.

The resulting test pieces were evaluated for impact strength and surface appearance. The results are shown in Table 1.

From Table 1, the molded products obtained by molding the resin composition of the present invention are 1! It was found that the IJ impact strength and appearance were excellent.

[Effects of the Invention] A resin composition in which components (B) and (C) are blended with an aromatic polyester provides molded articles with excellent surface appearance and good impact resistance.

Patent applicant Teijin Kaisha Ltd. ゛・、ノ \−,z’ 5571

Claims (1)

[Scope of Claims] 1) (A) 40 to 98% by weight of aromatic polyester;
B) Adding one or more vinyl monomers selected from the group consisting of methacrylic acid ester (b), aromatic monovinyl compound (c), and vinyl cyanide compound (d) to the butadiene polymer (a). 1 to 30% by weight of a graft copolymerized butadiene-based graft copolymer, (C) a copolymer consisting of an α-olefin and a glycidyl ester of an α,β-unsaturated acid, an acrylic ester, a methacrylic ester, and A thermoplastic resin composition comprising 1 to 30% by weight of a multiphase structural polymer obtained by graft copolymerizing at least one member selected from the group of aromatic monovinyl compounds. 2) The thermoplastic resin composition according to claim 1, wherein the aromatic polyester is polybutylene terephthalate. 3) The thermoplastic resin composition according to claim 1, wherein the butadiene-based graft copolymer is an acrylonitrile-styrene-butadiene copolymer or a methyl methacrylate-styrene-butadiene copolymer. 4) In the multi-phase structure polymer, the α-olefin is ethylene and the glycidyl ester of α,β-unsaturated acid is glycidyl methacrylate, Claim 1
The thermoplastic resin composition described in .