JPH0412901B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a resin composition, and more particularly to a thermoplastic resin composition that has excellent surface appearance, moldability, and mechanical properties, particularly low-temperature impact resistance. [Prior art] Aromatic polyester is generally a thermoplastic material that has various excellent properties including oxidation resistance and solvent resistance, and can be melt-molded to obtain fibers and films with good physical and mechanical properties. It is suitable for However, since these polymers have a highly crystalline structure, they have poor dimensional stability when molded by injection molding or the like, and also have poor impact resistance and heat resistance. On the other hand, aromatic polycarbonates (especially 4,4'-
Dihydroxydiphenylalkane-based polycarbonate) has the disadvantage of being extremely difficult to mold due to its excessively high melt viscosity and poor solvent resistance. Therefore, attempts were made to uniformly mix aromatic polyester and aromatic polycarbonate in a molten state to compensate for the above-mentioned defects of both polymers (for example,
36-14035)). By mixing aromatic polyester and aromatic polycarbonate in this way, the physical properties of aromatic polyester as a molding resin such as dimensional stability are improved, and at the same time, the melt viscosity of aromatic polycarbonate is reduced, making molding easier. However, the resin composition obtained in this way has the disadvantage that it has insufficient impact resistance, which limits its application to applications that require impact resistance. have As a method for improving the impact resistance of aromatic polyester and aromatic polycarbonate resin compositions,
A method of blending olefin or olefin copolymer has been proposed (Japanese Patent Application Laid-Open No. 89352/1989),
The impact resistance is not sufficiently improved, and since such resin compositions are incompatible, the obtained molded products tend to cause delamination and striped patterns on the surface, making it impossible to obtain a molded product with a good appearance. Therefore, in the present invention, in order to improve the impact resistance of such resin compositions, an olefin copolymer consisting of α-olefin and glycidyl ester of α,β-unsaturated acid was added, and an improvement in impact strength was observed. However, the properties at low temperatures were not sufficient, and satisfactory surface properties could not be obtained. [Object of the Invention] The object of the present invention is to provide a resin composition that has excellent surface appearance and good mechanical properties, particularly low-temperature impact properties, thermal properties, and moldability. [Structure of the invention] The present invention comprises (A) 4 to 95% by weight of aromatic polyester, (B) 4 to 95% by weight of aromatic polycarbonate (B), (C) methacrylic acid ester in butadiene polymer (A). (b) A butadiene-based graft copolymer obtained by graft copolymerizing one or more vinyl monomers selected from the group consisting of aromatic monovinyl compounds (c) and vinyl cyanide compounds (d) 1 to 20 % by weight, (D) 1 to 20% by weight of an ethylene copolymer, and (E) an olefinic copolymer consisting of an α-olefin and a glycidyl ester of an α,β-unsaturated acid.
It is a thermoplastic resin composition consisting of 0.5 to 10% by weight. The aromatic polyester (A) used in the present invention is a polyester having an aromatic group in the main chain of the polymer,
It is a polymer or copolymer obtained by a condensation reaction containing an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof as main components. Examples of the aromatic dicarboxylic acid component include dicarboxylic acids having a benzene nucleus such as terephthalic acid and isophthalic acid, naphthalene-2,6-dicarboxylic acid, and naphthalene-2,6-dicarboxylic acid.
Examples include dicarboxylic acids having a naphthalene nucleus such as 1,5-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, can also be used in an amount of 20 mol% or less of the acid component. . Examples of diol components include ethylene glycol, tetramethylene glycol, hexamethylene glycol,
Examples include aliphatic glycols such as diethylene glycol and cyclohexanedimethanol, diols having aromatic rings such as 1,4-bisoxyethoxybenzene and bisphenol A, and ester-forming derivatives thereof. The aromatic polyester used in the present invention may be not only one type of aromatic polyester but also a mixture of two or more types of aromatic polyester. Aromatic polycarbonate (B) used in the present invention
is particularly a 4,4'-dihydroxydiphenylalkane-based polycarbonate, and more specifically, 2,2-(4,4'-dihydroxydiphenyl)propane (hereinafter abbreviated as bisphenol A) as a dihydroxy component. Polycarbonates obtained by the transesterification method or the phosgene method are preferred. Furthermore, part or all of bisphenol A may be substituted with other 4,4'-dihydroxydiphenyl alkane, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl ether, etc. A mixture of two or more types of aromatic polycarbonates may be used. The butadiene-based graft copolymer (C) used in the present invention is selected from the group consisting of a butadiene-based graft polymer (a), methacrylic acid (b), an aromatic monovinyl compound (c), and a vinyl cyanide compound (d). It is obtained by graft copolymerizing one or more vinyl monomers. In the graft copolymer (C), the amount of the butadiene polymer (A) is 10 to 85% by weight, especially
It is preferably 30 to 70% by weight. When it is less than 10% by weight, the impact strength of the resulting resin composition is low, while when it is more than 85% by weight, the moldability of the resulting resin composition is undesirably reduced. 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 preferably 50% by weight or more. Vinyl monomers graft copolymerized to the butadiene polymer (a) include methacrylic acid ester (b), aromatic monovinyl compound (c), and vinyl cyanide compound.
Although one or more of (d) is used, the ratio of the vinyl monomers to each other is arbitrary, and a small proportion thereof may be replaced with another vinyl monomer. 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. Methacrylic acid ester has 1 to 4 carbon atoms
Alkyl esters are preferred, and methyl esters are particularly preferred. As aromatic monovinyl compounds,
Examples include styrene, vinyltoluene, α-methylstyrene, nuclear halogenated styrene, and vinylnaphthalene, with styrene being particularly preferred. Examples of vinyl cyanide compounds include acrylonitrile, 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 have a graft ratio of 15 to 15% from the viewpoint of impact resistance and surface appearance.
Preferably it is 200%. Here, the graft ratio is a value calculated from the following formula. "Graft ratio = (weight of acetone soluble component / weight of rubber component [component (a)] - 1) x 100" However, in the formula, the acetone insoluble component is calculated by thoroughly immersing the graft copolymer in acetone and then centrifuging it. It is determined by strictly collecting the insoluble precipitate by separation. The butadiene-based kraft copolymer (C) used in the present invention can be subjected to bulk polymerization, suspension polymerization, bulk suspension polymerization,
It can be produced by either solution polymerization or emulsion polymerization. In particular, when producing components with a high rubber content, it is desirable to produce them by emulsion graft polymerization. The butadiene-based graft copolymer (C) of the present invention may be used in combination with a hard thermoplastic resin, but if the butadiene-based polymer component (a) is
It is necessary for the amount to be 10% or more based on the total amount of the hard thermoplastic resin and the hard thermoplastic resin. The hard thermoplastic resin may be one obtained by polymerizing the same vinyl monomer as the vinyl monomer used in the graft copolymer (C), or a thermoplastic resin obtained from a different monomer. However, from the viewpoint of compatibility, those obtained from the same monomer are preferred. The ethylene copolymer (D) used in the present invention includes ethylene and propylene, 1-butene, 1-hexene, 1-decene, 1-4-methylbutene,
alpha-olefins or styrenes such as 4-methylpentene-1, acrylonitrile, vinyl acetate, vinyl propionate, acrylic esters,
Mainly composed of ethylenically unsaturated monomers such as methacrylic acid esters, diene monomers such as dicyclopentadiene, 1,4-hexadiene, ethylidenenorbornene, methylnorbornene, and 1,5-dicyclooctadiene. A copolymer may be mentioned, and the glass transition temperature of the copolymer is preferably 0°C or lower, particularly preferably -20°C or lower. α-olefin and α,β- used in the present invention
The α-olefin in the olefin copolymer (E) comprising glycidyl ester of an unsaturated acid is ethylene, propylene, butene-1, etc., and ethylene is particularly preferred. In addition, glycidyl ester of α,β-unsaturated acid 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,
These include glycidyl ethacrylate and glycidyl itaconate, and among them, glycidyl methacrylate is preferred. α in glycidyl group-containing polymers,
The copolymerization ratio of glycidyl ester of β-unsaturated acid is preferably 0.5 to 40% by weight, more preferably 1 to 30% by weight, more preferably 2 to 20% by weight. If the copolymerization amount is less than 0.5% by weight, the impact improvement effect will not be sufficient, and if it is more than 40% by weight, the fluidity during molding will decrease, which is undesirable. Alpha-olefins and glycidyl esters of alpha, beta-unsaturated acids can be copolymerized by standard copolymerization or grafting reactions. In addition, if the amount is 40% by weight or less, unsaturated monomers copolymerizable with the above copolymers, such as vinyl ethers, vinyl acetate,
One or more types of vinyl esters such as vinyl propionate, acrylic and methacrylic esters such as methyl, ethyl, propyl, and butyl, acrylonitrile, styrene, carbon monoxide, etc. may be copolymerized. Examples of preferred olefin copolymers include ethylene/glycidyl methacrylate copolymer, ethylene/vinyl acetate/glycidyl methacrylate copolymer, ethylene/carbon monoxide/glycidyl methacrylate copolymer, and ethylene/glycidyl acrylate copolymer. /vinyl acetate copolymer, among others, ethylene/glycidyl methacrylate copolymer is most preferred. Even if components (D) and (E) are blended into a resin composition consisting of aromatic polyester (A) and aromatic polycarbonate (B), the resulting molded product will have delamination, resulting in poor surface appearance and poor impact resistance. However, by adding component (C), it is possible to obtain a molded article that does not show stripes, has excellent gloss, and has excellent low-temperature impact resistance. The reason for this is not clear, but it is presumed that polyolefin, polyester, and polycarbonate are originally incompatible due to large differences in compatibility parameters, but the glycidyl group of component (E) and the terminal carboxyl group of polyester are chemically The olefin component of component (E) and the component (D), which is an ethylene copolymer, become compatible.
Component (D) and butadiene (C) component become compatible, and
It is thought that by making the styrene of component (C) compatible with the polycarbonate, the uniformity increases and a molded article with excellent surface properties without layer peeling is obtained. The mixing ratio of such a thermoplastic resin composition is preferably 4 to 95% by weight of component (A), 4 to 95% by weight of component (B), and 1 to 10% by weight of component (C), based on the resin composition. is 5 to 15% by weight, component (D) is 1 to 20% by weight, preferably 5 to 15% by weight, and component (E) is 0.5 to 10% by weight,
It should preferably be mixed to contain 1 to 5% by weight. If the content of component (A) is less than 4% by weight, the resulting composition will have insufficient solvent resistance, while if the content of component (A) is more than 95% by weight, the resulting composition will have insufficient dimensional stability. Inadequate sex. If the content of component (B) is less than 4% by weight,
The dimensional stability of the resulting composition is poor and the heat distortion temperature is not improved, which is insufficient. On the other hand, when the content of component (B) is more than 95% by weight, the moldability of the resulting composition is poor. Furthermore, if the content of component (C) is less than 1% by weight, the impact strength and surface appearance of the resulting composition will not be improved, while if it is more than 20% by weight, the heat distortion temperature of the composition will decrease, which is undesirable. .
If the content of component (D) is less than 1% by weight, the impact strength of the resulting composition will not be improved;
On the other hand, if the amount is more than 20% by weight, it is not preferable because not only the heat distortion temperature of the composition is lowered, but also the surface appearance is impaired even in the presence of component (C). Furthermore, if the content of component (E) is less than 0.5% by weight, the impact strength of the resulting composition will not be improved, while if it is more than 10% by weight, it will become a gel state and the surface properties will deteriorate, which is not preferable. The composition of the present invention may contain various additives (e.g., various stabilizers, pigments, flame retardants, mold release agents, inorganic fillers) as long as they do not impair the purpose of the present invention. good. The thermoplastic resin composition of the present invention can be prepared by any method of mixing solid substances (for example,
Methods using a Banbury mixer, heated rolls, or a single or 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 the Examples, "parts" and "%" are all based on weight, and impact strength was measured by the method of ASTM-256, and molding shrinkage rate was measured by the method of ASTM-955. The surface appearance was evaluated based on the striped pattern and gloss of the surface. Further, the reduced specific viscosity is a value measured at 35° C. by dissolving 1.2 g of the polymer in 100 ml of orthochlorophenol. Examples 1 to 5 and Comparative Examples 1 to 5 Polyethylene terephthalate (reduced specific viscosity
0.71), "Panlite L-1250" (product name; manufactured by Teijin Kasei KK) dried at 130°C for 5 hours as an aromatic polycarbonate, butadiene-styrene copolymer rubber as a butadiene-based graft copolymer
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 (grafting rate 57.3%),
Ethylene copolymer and α-olefin and α,
Olefinic copolymers consisting of glycidyl esters of β-unsaturated acids were uniformly mixed in various proportions shown in Table 1 in a V-type blender. The resulting mixture was heated to a barrel temperature using a 65mmφ extruder.
The mixture was melt-kneaded at 270°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 a test piece mold for measuring physical properties was attached to a 5-ounce injection molding machine, and the cylinder temperature was 270°C.
Mold temperature 90℃, injection pressure 700Kg/cm ² , cooling time 20
The test pieces were molded under molding conditions of 35 seconds and a total cycle of 35 seconds. The impact strength and surface appearance of the obtained test pieces were evaluated. The results are shown in Table 1.

[Table] As can be seen from Table 1, by using components (C), (D), and (E) in combination, molded products with excellent surface appearance and good impact resistance can be obtained. In addition, the molding shrinkage rate of polyethylene terephthalate is 0.019 cm/cm, whereas the molding shrinkage rate of the example is
It was 0.006-0.007cm/cm. Examples 6 to 10 and Comparative Examples 6 to 10 Polytetramethylene terephthalate (reduced specific viscosity 1.10) as aromatic polyester, "Panlite L-1225" (trade name; manufactured by Teijin Kasei KK) as aromatic polycarbonate, butadiene-based As a graft copolymer, a graft copolymer obtained by emulsion graft copolymerization of 50 parts of styrene and 20 parts of acrylonitrile in the presence of 30 parts of polybutadiene (grafting rate 82.5%), an ethylene copolymer, and α
Olefin copolymers consisting of olefins and glycidyl esters of α,β-unsaturated acids were evaluated in the same manner as in Example 1 at various ratios shown in Table 2. The results are shown in Table 2.

【table】

[Table] Note that the molding shrinkage rate of polytetramethylene tetophthalate was 0.021 cm/cm, whereas that of the present invention was 0.008 to 0.009 cm/cm. Comparative Example 11 Polyethylene terephthalate (reduced specific viscosity
0.71), "Panlite L-1225" (trade name manufactured by Teijin Kasei Ltd.) as an aromatic polycarbonate, and polybutadiene as a butadiene-based graft copolymer.
A composition was prepared by emulsion graft copolymerization of 50 parts by weight of styrene and 20 parts by weight of acrylonitrile in the presence of 30 parts by weight, and four components: an ethylene copolymer. The composition and physical properties of Comparative Example 11 as well as Example 3 are shown in Table 3.

【table】

[Table] As shown in Table 3, if component (E) is not added, the impact strength level will be low. This is because component (D) alone has little impact resistance improvement effect, but when used in combination with component (E), the improvement effect is synergistically improved.

Claims (1)

[Scope of Claims] 1 (A) 4 to 95% by weight of aromatic polyester, (B) 4 to 95% by weight of aromatic polycarbonate (B), (C) methacrylic acid ester (Ro) in butadiene polymer (A). ), a butadiene-based graft copolymer obtained by graft copolymerizing one or more vinyl monomers selected from the group consisting of aromatic monovinyl compounds (c), and vinyl cyanide compounds (d) 1 to 20% by weight , (D) 1 to 20% by weight of an ethylene copolymer, and (E) an olefin copolymer consisting of an α-olefin and a glycidyl ester of an α,β-unsaturated acid.
A thermoplastic resin composition consisting of 0.5 to 10% by weight.