Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Patent
1993-12-07
1995-07-04
Seccuro, Jr., Carman J.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
525199, 525200, 525188, C08L 2712, C08L 2722, C08L 3304, C08J 324
Patent
active
054301033
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to crosslinkable compositions.
BACKGROUND ART
Fluoroelastomers are outstanding in resistance to heat, oils, chemicals, solvents, oxidation, etc. and are useful in the fields of industrial materials and for other applications. However, since economy is not negligible for the prevalent use of these elastomers, it is presently unexpectable that fluoroelastomers will be used in remarkably increased quantities despite their outstanding properties. Various co-crosslinkable blend compositions have been developed to overcome this problem, or to remedy the drawback of fluororubbers, that is, to improve the low-temperature flexibility thereof or to reduce the specific gravity thereof.
For example, it has been reported to merely blend an acrylic elastomer and a fluoroelastomer or to use additives for the blend in an attempt to develop a material having the characteristics of both the acrylic elastomer and fluoroelastomer, whereas the material obtained still remains to be improved in physical properties, such as mechanical strength and compression set, heat resistance, etc.
Further with respect to blends of fluororubber and acrylic rubber, attempts have been made to select a crosslinking agent for crosslinking both fluororubber and acrylic rubber, and prevent the impairment of physical properties of the two polymers or give improved workability to the blend as disclosed in JR-A-40558/1977, JP-A-146752/1978, JP-A-101847/1979, JP-A-154446/1979, JP-A-156052/1979, JP-A-23128/1980, JP-A-63740/1983, etc.
Nevertheless, even if fluororubber and acrylic rubber are merely blended or the crosslinking agent for crosslinking both the rubbers is used, difficulty is encountered in keeping these rubbers homogeneously dispersed with good stability, and the attempt fails to achieve a satisfactory effect in preventing the impairment of the mechanical strength and other properties.
To remedy these drawbacks, JP-A-299859/1989, for example, discloses the technique of substantially crosslinking acrylic rubber only when fluororubber and acrylic rubber are blended to thereby diminish the size of dispersed acrylic rubber particles and cause molecules of both the rubbers to penetrate into each other through the interface therebetween for the prevention of separation at the interface. However, this method is not amenable to quantity production and encounters difficulty in giving a blend of stabilized properties with ease.
An object of the present invention is to provide a method of readily preparing a crosslinkable composition capable of giving moldings which are excellent in physical properties such as mechanical strength and compression set, heat resistance and workability.
The present invention provides a crosslinkable composition which comprises an internally crosslinked acrylic elastomer which is crosslinkable with a peroxide, a fluoroelastomer and a crosslinking agent for at least one of the elastomers.
According to the present invention, an internally crosslinked acrylic elastomer which is crosslinkable with a peroxide is used in place of the conventional acrylic elastomer along with a fluoroelastomer. This readily provides a crosslinkable composition capable of giving moldings which are excellent in physical properties such as mechanical strength and compression set, heat resistance and workability.
According to the present invention, the internally crosslinked acrylic elastomer which is crosslinkable with a peroxide is obtained by copolymerizing an acrylic monomer or monomers with a crosslinkable monomer having, for example, at least two unsaturated bonds different in radical reactivity. In the crosslinkable monomer, the unsaturated group having the higher radical reactivity participates in the polymerization reaction, while the unsaturated group of the lower radical reactivity remains as it is in the side chain of the resulting polymer. Although the method of internal crosslinking is not limited specifically, the elastomer can be readily obtained by copolymerizing a multifunctional mono
REFERENCES:
patent: 4045402 (1977-08-01), Bjerk et al.
patent: 4581412 (1986-04-01), Ohmori et al.
patent: 4614779 (1986-09-01), Watanabe
patent: 4877839 (1989-10-01), Conti-Ramsden
patent: 4988548 (1991-01-01), Takemura et al.
patent: 5051480 (1991-09-01), Coran
patent: 5053450 (1991-10-01), Coran
patent: 5095072 (1992-03-01), Kobayashi et al.
patent: 5100734 (1992-03-01), Miyabayashi
patent: 5100962 (1992-03-01), Sawada et al.
Matsumoto Kazuhisa
Minamino Etsuo
Noguchi Tsuyoshi
Ohata Hiroyuki
Shirai Yoshihiro
Daikin Industries Ltd.
Nissin Chemical Industry Co. Ltd.
Seccuro, Jr. Carman J.
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