JPH0114939B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a resin composition, and more particularly to a polycarbonate resin composition that has excellent solvent resistance, impact resistance, impact strength at low temperatures, and heat aging resistance of impact strength. Exterior parts of automobiles, such as bumpers, panels, and fenders, have traditionally been made of steel, but as fuel efficiency and weight have been reduced in recent years, there has been a strong desire to use plastic. Also, the advantages of plastics, such as their corrosion resistance and resistance to denting, are being reconsidered compared to steel. When plastics are used as automobile parts, high impact resistance and heat resistance are required, and polycarbonate resin is attracting attention as a material that can meet these characteristics. However, polycarbonate resin has the following four problems when its molded products are used as vehicle parts, especially automobile parts. (1) The impact strength of polycarbonate resin molded products is strongly dependent on the thickness. For example, the impact value with izots of a 3.2 mm thick (1/8 inch thick) product shows ductile fracture, whereas a 6.4 mm thick product shows ductile fracture.
It exhibits brittle failure at a thicker layer (1/4 inch thick), and the impact strength decreases significantly in the thicker region. (2)
The above-mentioned high notched impact value at a thickness of 3.2 mm also decreases rapidly at low temperatures. (3) When exposed to high temperatures, thermal aging occurs and impact strength decreases. (4) Due to low solvent resistance, large or complex shaped molded products with high residual stress will cause stress cracks when they come in contact with paint or gasoline. Of these four points, significant improvements are needed in (4) solvent resistance and (3) impact strength heat aging resistance. The purpose of the present invention is to improve the solvent resistance of polycarbonate resin, the impact resistance of thick molded products, the impact strength at low temperatures, and the heat aging resistance of impact strength, and to improve the heat aging resistance of polycarbonate resin for use in automobile exterior products such as bumpers. The object of the present invention is to provide a resin composition that can be used as a resin composition. The purpose of the present invention is to prepare polycarbonate resin (A) from 10 to
90 parts by weight, aromatic polyester (B) 5 to 70 parts by weight,
Butyl rubber (C) 1 to 15 parts by weight, acrylic elastic polymer (D) 1 to 20 parts by weight, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-vinyl chloride copolymer, and ethylene-tetrafluoride It consists of 1 to 15 parts by weight of at least one olefinic polymer (E) selected from the group consisting of ethylene copolymers, and the above (B) is added to the total amount of the above (C), (D) and (E) components. This can be achieved by a resin composition characterized in that the weight ratio of the components is 1 to 5. The resin composition of the present invention has excellent resistance to various solvents including gasoline and impact aging properties compared to polycarbonate resin alone, and has excellent impact resistance for thick-walled molded products and at low temperatures. It has improved impact strength, and has excellent mechanical properties such as formability and tensile strength, surface appearance, and resistance to heat discoloration, so it has the advantage of being able to be used in automobile exterior parts such as bumpers, panels, fenders, etc. . Among the components constituting the resin composition of the present invention, the combination of polycarbonate resin and aromatic polyester is
The combination of polycarbonate resin and butyl rubber was disclosed in Japanese Patent Publication No. 14035 and Japanese Patent Publication No. 53-12537 for the purpose of improving the impact resistance of thick-walled molded products.
Japanese Patent Publication No. 42-18823 describes a ternary combination of polycarbonate resin, polyester, and polyolefin for the purpose of lowering the melt viscosity of polycarbonate resin. The combination of methylene terephthalate and polyethylene is described in JP-A-50-130847 for the purpose of improving tracking resistance, and the combination of polycarbonate resin, polyester, ethylene, and ethylene-vinyl acetate copolymer is described in Bending strength, 3.2mm thickness impact strength,
Each of these methods is disclosed in Japanese Patent Publication No. 51-39749 for the purpose of improving the finish workability of the gate portion of a molded product. However, none of these documents describes or suggests any objects or advantages similar to those of the present invention. And these do not have the features like the present invention. The polycarbonate resin (A) used in the present invention can be prepared by reacting a divalent phenol with a carbonate precursor such as phosgene in the presence of an acid acceptor and a molecular weight regulator, or by reacting a divalent phenol with a carbonate precursor such as diphenyl carbonate. It can be produced by transesterification reaction with The divalent phenol that can be used here is preferably bisphenols, and 2,2-bis(4-hydroxyphenyl)propane (hereinafter referred to as bisphenol A) is particularly preferred. Also, bisphenol A
may be partially or entirely replaced with other dihydric phenols. Examples of divalent phenols other than bisphenol A include hydroquinone, 4,4'-dihydroxydiphenyl, bis(4-hydroxyphenyl)alkane, bis(4-hydroxyphenyl)cycloalkane, and bis(4-hydroxyphenyl). enyl) sulfone, bis(4-hydroxyphenyl) sulfide, bis(4-hydroxyphenyl) sulfoxide, bis(4-hydroxyphenyl) ketone, bis(4-hydroxyphenyl) ether, and bis(3,5 Mention may be made of halogenated bisphenols such as -dibromo-4-hydroxyphenyl)propane. The polycarbonate resin may be a homopolymer of these dihydric phenols, a copolymer using two or more of these dihydric phenols, or a mixture thereof. Alternatively, it may be a thermoplastic randomly branched polycarbonate obtained by reacting a polyfunctional aromatic compound with a dihydric phenol and a carbonate precursor. Aromatic polyester used in the present invention
(B) is an alkylene glycol, e.g. 2 to 2 carbon atoms.
It is a reaction product (polymer) of No. 10 glycol and an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, etc. or an ester-forming derivative thereof. Examples of the glycol include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, and 1,10-decamethylene glycol. Preferred aromatic dicarboxylic acids include terephthalic acid and isophthalic acid. Specific examples of aromatic polyesters include poly(ethylene terephthalate),
Poly(1,4-butylene terephthalate), amorphous poly(ethylene terephthalate) copolyester, amorphous poly(1,4-butylene terephthalate) copolyester, amorphous poly(1,4-cyclohexane dimethylene terephthalate) Examples include copolyester. As the butyl rubber (C) used in the present invention, for example, isobutylene and 1 to 7% by weight of isoprene are combined with Friedel rubber such as aluminum chloride.
Examples include synthetic rubbers with a low degree of unsaturation obtained by copolymerizing in the presence of a Crafts-type metal halide at a low temperature, for example, about -100°C. The acrylic elastic polymer (D) used in the present invention is a copolymer mainly composed of acrylic ester and copolymerized with copolymerized monomers such as methacrylic ester, butadiene, styrene, acrylonitrile, etc. The number of carbon atoms in the group is 2~
12 alkyl acrylates (e.g. 2-ethylhexyl acrylate, n-butyl acrylate, etc.)
40-95% by weight, 5-40% by weight of butadiene, 0-30% by weight of methyl methacrylate and 0.01-3% by weight.
crosslinking agent (e.g. ethylene dimethacrylate etc.)
First, 20 to 80 parts by weight of styrene is added to a latex containing 50 to 80 parts by weight of a crosslinked rubber copolymer with an average particle size of 0.1 to 0.3μ obtained by emulsion polymerization of a mixed monomer consisting of % and methyl methacrylate
20-50% by weight and 0-60% by weight of acrylonitrile and a crosslinking agent (e.g. ethylene dimethacrylate,
After adding and polymerizing 10 to 40 parts by weight of a mixed monomer containing 0.1 to 2% by weight of divinylbenzene, etc., the carbon number of the alkyl group containing 0.1 to 4% by weight of the crosslinking agent (e.g. ethylene dimethacrylate, divinylbenzene, etc.) It is a multicomponent resin obtained by further addition polymerization of 5 to 25 parts by weight of 1 to 4 alkyl methacrylates (for example, methyl methacrylate). A specific example of such an acrylic elastic polymer is one commercially available from Kureha Chemical Industry Co., Ltd. under the product name HIA-15. The olefinic polymer (E) used in the present invention is selected from the group consisting of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-vinyl chloride copolymer, and ethylene-tetrafluoroethylene copolymer. Such olefinic polymers may be commercially available. In the resin composition of the present invention, the blending ratio of each component is such that the polycarbonate resin (A) is 10 to 90 parts by weight, preferably 20 to 80 parts by weight, and the aromatic polyester (B) is
is 5 to 70 parts by weight, preferably 10 to 50 parts by weight, butyl rubber (C) is 1 to 15 parts by weight, preferably 2 to 10 parts by weight, and the acrylic elastic polymer (D) is 1 to 10 parts by weight. 20 parts by weight, preferably 2 to 15 parts by weight,
The olefin polymer (E) is 1 to 15 parts by weight, preferably 2 to 10 parts by weight, and the above (C), (D) and (E)
The weight ratio of the above component (B) to the total amount of components is 1 to
It is 5. If the blending amounts of the components (B), (C), (D), and (E) do not satisfy the above-mentioned ranges, the resin composition of the present invention may have poor solvent resistance, impact resistance, and low-temperature properties. Impact resistance and heat aging resistance are not obtained, and (C)
If the blending amount of components (D) and (E) exceeds the above-mentioned range, it is not preferable because layer peeling may occur and the appearance of the molded product may be impaired or heat resistance may be reduced. The resin composition of the present invention can be prepared by any method. As a method, for example, aromatic polyester (B), butyl rubber (C), acrylic elastic polymer (D), and olefin polymer (E) are added to polycarbonate resin (A), and a V-type blender, super mixer, etc. (C), (D) and (E) components, or (C) and (D) components, or (C) There is a method in which components (E) and (E) are mixed in advance using a kneading roll or a Banbury mixer, and this is mixed with the remaining components and the aromatic polyester (B) into the polycarbonate resin (A) directly or in a molten state. In particular, a method of mixing in multiple stages is preferred because it improves the degree of kneading. The composition of the present invention includes additives for the purpose of modifying the resin, such as reinforcing agents such as glass fibers, heat stabilizers, antioxidants, foaming agents, light stabilizers, flame retardants, plasticizers, mold release agents, etc. agents, antistatic agents, fillers, facial dyes, etc. can be added. Also, for example, polystyrene, polymethyl methacrylate, AS resin,
Other resins such as ABS resin and polyphenylene oxide may be mixed. The present invention will be explained below using examples. still,
Parts in the examples mean parts by weight. Further, evaluation was performed in the following manner. 1 Solvent resistance evaluation method: Using an injection molding machine, pre-dried pellets were formed into a flat plate of 127 mm x 127 mm x 3 mm, and after cutting a hole of 6 mm diameter with a drill, the temperature was 23 ° C and the humidity was 50 °C.
% for 24 hours. After treatment, the tube was tightened with an M6 bottle nut to a torque of 70 kg cm, each test solution was applied, and the presence or absence of cracks was observed after 5 minutes. The absence of cracks indicates excellent solvent resistance. 2 Impact resistance evaluation method: Using an injection molding machine, pre-dried pellets were molded into 64mm x 12.7mm x 3.18mm and 64mm x 12.7mm x
6.35mm impact specimens were each molded and 0.25mm
Added an R notch. The test piece was placed at a temperature of 23℃ and humidity.
After processing at 50% for 24 hours, the impact strength was measured using an Izotsu impact tester (manufactured by Toyo Seiki Co., Ltd.). The higher the impact strength, the better the impact resistance. 3 Impact resistance evaluation method at low temperature: The notched impact test piece molded in 2 above was tested at -10
After being left in a constant temperature chamber at ℃ for 1 hour, it was taken out from the constant temperature chamber, and the impact strength was immediately measured using the Izot impact tester described in 2 above. The higher the impact strength, the better the impact resistance at low temperatures. 4. Heat aging resistance of sanitary strength: After leaving the notched impact test piece molded in 2 above in a thermostatic chamber at 125°C for 65 hours, it was taken out from the thermostatic chamber and heated to a temperature of 23°C.
℃ and 50% humidity for 24 hours. After the treatment, impact strength was measured using the above-mentioned Izot impact tester. The higher the impact strength, the higher the heat aging resistance of the impact strength. Examples 1 to 10 and Comparative Examples 1 to 9 Pre-dried polycarbonate resin (A) (Teijin Kasei Ltd.: Panlite L-1250), aromatic polyester shown in Table 1 (B), butyl rubber (C) (manufactured by Japan Synthetic Rubber Co., Ltd.: IIR-065), acrylic elastic polymer (D)
(manufactured by Kureha Chemical Industry Co., Ltd.: HIA-15) and the olefin polymer (E) shown in Table 1 in the amounts shown in Table 1 were mixed using a V-type blender, and then a 30 mmφ extruder (center It was extruded into pellets using VSK-30 (manufactured by Machinery Co., Ltd.). Using the obtained pellets, test pieces were injection molded by the method shown in the evaluation method above, and their solvent resistance, impact resistance, impact resistance at low temperatures, and heat aging resistance of impact strength were evaluated. The results are shown in Table 1.

【table】

Table 1 shows that the resin composition of the present invention is excellent in solvent resistance, impact resistance, impact resistance at low temperatures, and heat aging resistance of impact strength.

Claims (1)

[Claims] 1 Polycarbonate resin (A) 10 to 90 parts by weight, aromatic polyester (B) 5 to 70 parts by weight, butyl rubber (C)
1 to 15 parts by weight, 1 to 20 parts by weight of acrylic elastic polymer (D), and polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-vinyl chloride copolymer, and ethylene-tetrafluoroethylene copolymer 1 to 15 parts by weight of at least one olefinic polymer (E) selected from the group consisting of
A resin composition characterized in that the weight ratio of component (B) to the total amount of components (C), (D), and (E) is 1 to 5.