JPH04311760A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin composition suitable for various kinds of automobile parts, mechanical parts, etc., excellent in compatibility of polybutylene terephthalate resin with polyamide resin, further excellent in mechanical properties, heat properties and water resistance. CONSTITUTION:(A) A polybutylene terephthalate resin is blended with (B) a polyamide resin, (C) a modified polypropylene-based resin obtained by grafting preferably 0.5-2wt.% unsaturated carboxylic acid anhydride or a derivative thereof (preferably maleic anhydride) on a polypropylene-based resin, (D) a glycidyl group-containing copolymer (ethylene/glycidyl methacrylate copolymer or methyl methacrylate/glycidyl methacrylate copolymer) in a blending ratio (weight ratio) satisfying formula I to formula III in a ratio of the component A/B of preferably 1/3-3 by weight and optionally a fiber reinforcing agent, a filler, an electrically conductive filler, a flame retardant, etc., to give a thermoplastic resin composition having excellent compatibility of the component A with the component B.

Description

Description: [0001] The present invention relates to a thermoplastic resin composition useful as various automobile parts, mechanical parts, and electrical/electronic parts. [0002] In general, polyamide resins are widely used as synthetic fibers because of their excellent physical and chemical properties, and in recent years, they have also been used as molding materials. This is because polyamide resin is among thermoplastic resins and has high mechanical strength, excellent abrasion resistance, chemical resistance, and heat resistance, and has sufficient performance as engineering plastics. by. On the other hand, polybutylene terephthalate resin also has sufficient performance as an engineering plastic, and is excellent in mechanical properties, electrical properties, chemical resistance, and moldability. Although polybutylene terephthalate and polyamide each have excellent performance as described above, they also have drawbacks, and therefore, attempts have been made to combine the two in order to improve these drawbacks. It has been carried out since. For example, Japanese Patent Publication No. 47-19101, Japanese Patent Publication No. 47-24
No. 465, JP-A-48-56742, JP-A-49-114661, etc. disclose changes in the blending composition of polyesters such as polybutylene terephthalate and polyamide, and the use of fibrous reinforcing materials as additives. Techniques have been disclosed that attempt to improve the problems caused when polyester and polyamide are combined by using an inorganic filler or an inorganic filler in combination. However, when mixing polybutylene terephthalate and polyamide, a melt-kneading method is usually used, but since the two are poorly compatible, it is not possible to obtain a uniform kneaded product. There is a problem in that the mechanical properties of the molded product obtained from the method, especially the tensile elongation at break and the impact strength, are extremely low. [0006] Furthermore, simply combining polybutylene terephthalate and polyamide has a problem in water resistance. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its purpose is to improve the compatibility between polybutylene terephthalate and polyamide, and to uniformly coat polybutylene terephthalate with polyamide. Kneading is performed, and mechanical properties,
An object of the present invention is to provide a thermoplastic resin composition having excellent thermal properties and water resistance. [Means for Solving the Problems] The above object is to obtain polybutylene terephthalate resin (A), polyamide resin (B)
, a modified polypropylene resin (C) grafted with an unsaturated carboxylic acid anhydride or a derivative thereof, and a copolymer (D) having a glycidyl group, and the blending ratio (weight ratio) thereof is the following formula: This is achieved by a thermoplastic resin composition that satisfies (1) to (3). 50≦100{(A)+(B)}/{(A)+(B
)+(C)}≦97

...(1
) 3≦100(C)/{(A)+(B)+(C
)}≦50...(2) 0.1
≦100(D)/{(A)+(B)+(C)}≦5
...(3) [0009] The present invention will be explained in detail below. The polybutylene terephthalate resin (A) used in the present invention is a polymer obtained by reacting an aromatic dicarboxylic acid or its diester with a glycol whose main glycol component is tetramethylene glycol by a known method. Specifically, the main component is terephthalic acid or dimethyl terephthalate, and isophthalic acid, dimethyl terephthalate, and
, 6-naphthalene dicarboxylic acid, 4,4'-diphenyl dicarboxylic acid, 4,4'-diphenoxyethane dicarboxylic acid, sebacic acid, adipic acid, etc., and tetramethylene glycol. It is obtained by polycondensing ethylene glycol or a glycol component formed by appropriately combining ethylene glycol, ethylene oxide, trimethylene glycol, hexamethylene glycol, decamethylene glycol, cyclohexanedimethanol, etc. as a main component. Further, an oxyacid component such as P-oxybenzoic acid may be used in combination. The polyamide resin (B) used in the present invention includes those prepared from a polymerizable monoamino monocarboxylic acid or an amide-forming derivative thereof, or a suitable diamine and a suitable dicarboxylic acid or an amide-forming derivative thereof. It will be done. Examples include nylon 4, nylon 6, nylon 7, nylon 8, nylon 11, nylon 12,
Examples include homopolymers such as nylon 66, nylon 69, nylon 610, nylon 611, nylon 612, and nylon 6T, as well as mixtures and copolymers of two or more of these. Also included are those having an amino group at the molecular end and capable of reacting with a carboxylic acid-containing modifier. In the thermoplastic resin composition of the present invention, the weight composition ratio of polybutylene terephthalate resin (A) and polyamide resin (B) is 1/3≦(A)/(B)≦3. This is desirable. When (A)/(B) exceeds 3, toughness tends to decrease, and tensile elongation at break and impact resistance tend to be insufficient. On the other hand, (A)/(B) is 1/3
If it is less than 20%, water resistance tends to be insufficient. The modified polypropylene resin (C) used in the present invention is obtained by grafting an unsaturated carboxylic acid anhydride or a derivative thereof to a polypropylene resin alone or to a resin mixture containing the polypropylene resin as the main component and a small amount of other resins. It is something. Polypropylene resins used in the present invention include stereoregular polypropylene, atactic polypropylene, propylene and other olefins, such as
Examples include block or random copolymers with ethylene etc., and mixtures thereof. [0016] Further, as the unsaturated carboxylic acid anhydride or its derivative to be grafted onto the polypropylene resin,
Examples include maleic anhydride, citraconic anhydride, metal salts thereof, amide compounds, imide compounds, and the like. Among these, maleic anhydride is most preferred. [0017] As a method for grafting a carboxylic acid anhydride or its derivative onto a polypropylene resin, for example, a radical generator is present in the polypropylene resin,
Examples include a method in which one or more of the above-mentioned unsaturated monomers is subjected to radical addition in the presence or absence of a solvent or dispersion medium. In particular, when adding in a molten state, a melt kneader such as an extruder, kneader, or Banbury mixer may be used. The modified polypropylene resin used in the present invention preferably contains 0.5 to 2% by weight of an unsaturated carboxylic acid anhydride or a derivative thereof as a graft component. If the amount is less than 0.5% by weight, it will be difficult to obtain a composition with uniform dispersion properties when used in the thermoplastic resin composition of the present invention. On the other hand, if it exceeds 2% by weight, the molded product tends to be colored. In the present invention, containing 0.5 to 2% by weight of an unsaturated carboxylic anhydride or its derivative means that the unsaturated carboxylic anhydride or its derivative is contained in a resin whose main component is a polypropylene resin. Even if the derivative is grafted in an amount of 0.5 to 2% by weight, more than 2% by weight is grafted, and this is mixed with an unmodified polypropylene resin, and the graft monomer component is added in this mixture as 0.5 to 2% by weight.
It may also contain. [0020] The above polybutylene terephthalate resin (A
), the blending ratio (weight ratio) of the polyamide resin (B) and the modified polypropylene resin (C) is determined by the following formulas (1) and (2).
) is required. 50≦100{(A)+(B)}/{(A)+(B
)+(C)}≦97

...(1
) 3≦100(C)/{(A)+(B)+(C
)}≦50 (2) Preferably, the following formulas (4) and (5) are satisfied. 60≦100{(A)+(B)}/{(A)+(B
)+(C)}≦95

...(4
) 5≦100(C)/{(A)+(B)+(C
)}≦40 (5) In formula (2), 100(C)/{(A)+(B)+(
C)} is less than 3, the dispersibility is poor and the tensile elongation at break, impact resistance and water resistance are insufficient. On the other hand, 50
If it exceeds this, the heat resistance will be significantly reduced. Next, the copolymer (D) having a glycidyl group used in the present invention refers to α-olefins such as ethylene, propylene, butylene, isobutylene, and pentene, vinyl acetate, vinyl propionate, vinyl butyrate, and benzoic acid. Vinyl monocarboxylic acid vinyl ester, methyl acrylate, ethyl acrylate, propyl acrylate,
One or more unsaturated monomers selected from α, β-unsaturated acid esters of monoalcohols such as butyl acrylate, methyl methacrylate, butyl methacrylate, acrylonitrile, maleic anhydride, styrene, α-methylstyrene, etc. It is obtained by adding a glycidyl group-containing unsaturated monomer to the polymer and copolymerizing it. Examples of the glycidyl group-containing unsaturated monomer include glycidyl methacrylate, glycidyl acrylate, vinyl glycidyl ether, allyl glycidyl ether, ω-glycidyl alkyl methacrylate, and ω-glycidyl alkyl acrylate. Copolymers having glycidyl groups that are particularly useful in the present invention include ethylene/glycidyl methacrylate copolymers, methyl methacrylate/glycidyl methacrylate copolymers, and styrene/acrylonitrile/glycidyl methacrylate copolymers. The amount of the glycidyl group-containing copolymer (D) used in the present invention must satisfy the following formula (3) in terms of weight ratio. 0.1≦100(D)/{(A)+(B)+(
C)}≦5 (3) Preferably, the following formula (6) is satisfied. 0.2≦100(D)/{(A)+(B)+(
C)}≦3...(6) Formula (3
), 100(D)/{(A)+(B)+(C)
} is less than 0.1, the effect of improving dispersibility is extremely insufficient, and the tensile elongation at break and impact resistance are significantly reduced. On the other hand, if it exceeds 5, the viscosity increases significantly and molding or kneading becomes impossible. The method for producing the resin composition of the present invention is not particularly limited, but it is necessary that the polybutylene terephthalate resin, polyamide resin, modified polypropylene resin, and glycidyl group-containing copolymer are sufficiently mixed. For example, a method in which four components are uniformly melt-kneaded simultaneously using a twin-screw kneading extruder, or two types of compositions obtained by melt-kneading two components in advance using a single-screw or twin-screw kneading extruder, Examples include a method of melt-kneading using a twin-screw kneading extruder. The obtained thermoplastic resin composition may be molded by any commonly known method such as injection molding, extrusion molding, blow molding, and compression molding. The thermoplastic resin composition of the present invention may optionally be reinforced with fibers such as glass fibers, carbon fibers, calcium metasilicate, potassium titanate, ceramic fibers, etc., which are usually used in thermoplastic resin compositions. fillers such as mica, silica, alumina, glass beads, calcium carbonate, conductive fillers such as iron fibers, brass fibers, stainless steel fibers, aluminum flakes, nickel coated glass fibers, nickel coated carbon fibers, iron powder, bromine antimony compounds such as antimony trioxide compounds, flame retardant aids such as zirconium oxide and molybdenum oxide, nucleating agents, antioxidants, ultraviolet absorbers, heat stabilizers, Additives such as lubricants, mold release agents, colorants including dyes and pigments may be appropriately blended. [0030] As described above, the thermoplastic resin composition of the present invention has good compatibility with polybutylene terephthalate resin and polyamide resin, and also has good mechanical properties, thermal properties, and water resistance. It is suitable for various automobile parts, mechanical parts, and electrical/electronic parts. The present invention will be specifically explained below with reference to Examples. In addition, physical property evaluation was performed according to the following method. (1) Tensile strength: ASTM D-638 (2) Tensile elongation at break: ASTM D-638 (3) Izod impact strength: (notched, 1/4 inch) ASTM D-
256 (4) Heat distortion temperature: (test load 4.6 kg/cm2)
ASTM D-648 (5) Water absorption rate: JIS No. 1 test piece in 80°C water 5
Time (Examples 1 to 7, Comparative Examples 1 to 4) Polypropylene resin (J300 manufactured by Mitsui Petrochemical Co., Ltd.) 9
9 parts by weight, 1 part by weight of maleic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) and 0.3 parts by weight of di-t-butyl peroxide (Perbutyl D, manufactured by Nippon Jushi Co., Ltd.) as a radical generator, After preliminary mixing, the mixture was melt-mixed using a 30 mm diameter biaxial kneading extruder in different directions to obtain pellets of a modified polypropylene resin into which 1% by weight of maleic anhydride was grafted. Polybutylene terephthalate resin (Kanebo Co., Ltd.)
Co., Ltd. PBT724), polyamide resin (nylon 6,
Kanebo Nylon MC-102 (manufactured by Kanebo Co., Ltd.), a modified polypropylene resin, and a copolymer having a glycidyl group (ethylene/glycidyl methacrylate copolymer, grade name Bremmer CP-15) were blended in the composition shown in Table 1, After preliminary mixing, the mixture was melt-mixed using a 30 mm diameter biaxial kneading extruder in different directions to obtain pellets. In Comparative Example 6, significant thickening was observed during kneading and extrusion, and pellets could not be obtained. After drying the obtained pellets under reduced pressure, they were subjected to injection molding to obtain test pieces, which were subjected to physical property tests. The results are also shown in Table 1. [Table 1] (Example 8) Nylon 66 (manufactured by Kanebo Co., Ltd., Kanebo Nylon MC-30) was used as the polyamide resin.
The same resin composition as in Example 3 was used, except that 0) was used, and the same evaluation was performed. The results are shown in Table 2. [Table 2] (Example 9) As a copolymer having a glycidyl group, styrene/acrylonitrile/glycidyl methacrylate copolymer (manufactured by NOF Corporation) Bremmer CP
-20SA) was used, the same resin composition as in Example 3 was used, and the same evaluation was performed. The results are shown in Table 3. [Table 3] (Examples 10 to 12) After pellets into which 1.5% by weight of maleic anhydride was grafted as a modified polypropylene resin were obtained in the same manner as in Example 1 and others. The same resin as in Example 3 was used, except that the maleic anhydride content was diluted with a polypropylene resin (J300 manufactured by Mitsui Petrochemical Co., Ltd.) so that the content of maleic anhydride was as shown in Table 4 relative to the polypropylene resin. The composition was blended and the same evaluation was performed. The results are also shown in Table 4. [0041] From the results shown in Tables 1 to 4, the thermoplastic resin composition of the present invention was excellent in mechanical properties, thermal properties, and water resistance.

Claims (1)

[Claims] [Claim 1] Polybutylene terephthalate resin (A
), a polyamide resin (B), a modified polypropylene resin grafted with an unsaturated carboxylic anhydride or its derivative (C), and a copolymer having a glycidyl group (D)
, and its blending ratio (weight ratio) is according to the following formula (
A thermoplastic resin composition that satisfies 1) to (3). 50≦100{(A)+(B)}/{(A)+(B
)+(C)}≦97

...(1
) 3≦100(C)/{(A)+(B)+(C
)}≦50...(2) 0.1
≦100(D)/{(A)+(B)+(C)}≦5
...(3)