JPS6028313B2 - Elastomer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an elastomer composition that has excellent dimensional stability and secondary processability, as well as excellent weather resistance and heat deterioration resistance.

A polyester elastomer using polyester as a hard segment and polyether as a soft segment has excellent heat resistance and rubber elasticity, and has a wide range of applications as an engineering elastomer.

However, since it contains crystalline hard segments, it has a high molding shrinkage rate and is prone to appearance defects such as whiskers. Furthermore, due to its chemical structure, it also has the disadvantage of poor secondary processability such as paintability and adhesiveness. Mixture of A spotted resin or M Shigeru resin and polyester elastomer (Samurai Sekisho Kyukyu-252
) has been proposed, but there were still problems in that the weather resistance and heat aging resistance were significantly inferior.

Attempts were made to improve these drawbacks of polyester elastomers by blending polybutadiene or ethylene-propylene rubber, but no effect was found due to the rubber blend.

As a result of intensive research into elastomers that have excellent dimensional stability and secondary processability, as well as weather resistance and heat deterioration resistance, the present inventors have found that, rather than using ethylene-propylene rubber itself, they have developed monomers based on ethylene-propylene-based rubber. By mixing the polymer obtained by graft polymerization with a polyester elastomer, it is possible to obtain a composition that not only has excellent dimensional stability and secondary processability, but also has excellent film resistance and heat deterioration resistance. -The present invention was achieved by discovering that.

That is, the present invention provides polyester elastomer 20 to 8
and one or more compounds selected from at least two groups of aromatic pinyl compounds, vinyl cyanide compounds, and methacrylate ester compounds are graft-polymerized to a rubber copolymer mainly composed of ethylene-propylene and ethylene-propylene. (hereinafter referred to as AES resin).

) 80-2% by weight. The polyester elastomer used in the present invention includes a high melting point, crystalline hard segment made of polyester of aromatic dicarboxylic acid such as terephthalic acid and isophthalic acid, and a low melting point soft segment containing a polyether component such as polyalkylene ether glycol. It is a block copolymer composed of segments.

For example, a polyester ether block formed by polycondensation reaction or transesterification reaction of dimethyl terephthalate, 1,4-phthanediol, poly(tetramethylene oxide) glycol at 200 to 25,000 in the presence of a catalyst, and obtained by removing water or methanol. Examples include copolymers.

A rubber copolymer mainly composed of ethylene-propylene is ethylene-propylene, which is composed only of ethylene and propylene.

In addition to pyrene rubber, it can also be used as a third component, such as dicyclobentadiene, ethylidenenorbornene,
- It also includes ethylene-propylene terpolymers containing 4-hexadiene, 1,5-hexadiene, 1,4-cycloheptadiene, 1,5-cyclooctadiene, etc., and mixtures thereof. The molar ratio of ethylene to propylene in the rubber copolymer is preferably in the range of 5:1 to 1:3.

Further, in the case of an ethylene-propylene terpolymer, the proportion of unsaturated groups preferably has an iodine value in the range of 4 to 50.

Examples of the aromatic vinyl compound include styrene, Q-methylstyrene, Q-chlorostyrene, dimethylstyrene, etc., with styrene being preferred.

Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile, with acrylonitrile being preferred. Examples of the methacrylic acid ester compound include ester compounds such as methyl, ethyl, propyl, butyl, benzyl, and hexyl, with methyl methacrylate being preferred.

One or more compounds selected from at least two groups among these aromatic vinyl compounds, vinyl cyanide, and methacrylate ester compounds are used in the graft polymerization.

Although the weight ratio of such a compound and the rubber co-vehicle combination is not particularly limited, it is preferably 95 to 4% by weight of the compound,
5-6% by weight of rubber copolymer. AES resin is manufactured by a bulk polymerization method, an emulsion polymerization method, a solution polymerization method, or the like.

The elastomer composition of the present invention comprises 20 to 80% by weight of polyester elastomer and 80 to 20% by weight of AES resin.
Consisting of

Polyester elastomer less than 2% by weight (AES
If the resin content exceeds 80% by weight, it does not exhibit much rubber elasticity, becomes more like a hard resin composition than an elastomer, and loses its characteristics as an elastomer. On the other hand, if the polyester elastomer exceeds 8% by weight (AES resin is less than 2% by weight), the disadvantages of polyester elastomers such as whiskers, dimensional stability such as mold shrinkage rate, and secondary processability are improved. It also tends to have poor aging resistance and heat deterioration resistance. Polyester elastomer and A
Mixing with the ES resin can be carried out using a known method such as a Banbury mixer or an extruder.

In addition, additives such as stabilizers, plasticizers, antistatic agents, thickeners, beam pigments, and fillers are added during mixing, and AS (acrylonitrile styrene) resin, as long as it does not affect weather resistance and heat deterioration resistance. It is also possible to add MS (methyl methacrylate-styrene) resin, ABS resin, M-mo resin, and the like. The present invention will be explained in detail below using examples.

Example [Polyester elastomer] Hytre 1405 manufactured by EI DuPont
"Belprene P-4 Hada" and "Belprene P-17 Plate B" manufactured by Toyobo Co., Ltd. [AES resin] AES resins were created by the following method.

Iodination: 8.5, Mooney viscosity: 61, propylene content: 4% by weight, 30 parts by weight of an ethylene-propylene rubber copolymer containing ethylidene norbornene as a gene component, 200 parts by weight of n-hexane and dichloride. ethylene 1
After adding 30 parts by weight of acrylonitrile, 70 parts by weight of styrene and 1 part by weight of penzoyl peroxide, the solution was heated at 670 liters for 60 lq hours in a nitrogen atmosphere. p. m. It was polymerized under the supervision of Azusa Taka.

The polymerization solution was brought into contact with a large excess of methanol, and the deposited precipitate was separated and dried to obtain an AES resin with a rubber content of 28.2%. Polyester elastomer and AES resin were mixed using a 4-ratio extruder manufactured by Thermo Plastics, formed into a pellet, and a test piece was prepared using a 5-ounce injection molding machine manufactured by Nissei Plastics.

Table 1 shows each composition and performance.

*I ABS resin (acrylonitrile-butadiene-styrene polymer) “Classic MH” manufactured by Sumitomo Nogatatsu Co., Ltd. *2 Yield point strength *3 A two-component urethane paint is used. The item was judged as ×.

[Brief explanation of the drawing]

FIG. 1 shows the relationship between the weatherometer irradiation time and elongation retention for compositions Nos. 4 and 8. FIG. 2 shows the relationship between the deterioration time and elongation retention rate of compositions Nos. 4 and 8 when opened at 110°C. Figure 1 2
figure

Claims (1)

[Claims] 1 A rubber copolymer mainly composed of 20 to 80% by weight of a polyester elastomer and ethylene-propylene, and one or more each selected from at least two groups of aromatic vinyl compounds, vinyl cyanide compounds, and methacrylic acid ester compounds. An elastomer composition characterized by comprising 80 to 20% by weight of a polymer obtained by graft polymerization of a compound.