EP0316855A2
Expired / Lapsed
EP
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A rubber composition
Assignee: Shin-Etsu Chemical Co Ltd
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Filing: 1988-11-15
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Granted: —
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Expires: 2008-11-15
Abstract
Abstract The polymeric ingredient of the inventive-rubber composition is an acrylic polymer modified with a mercapto-containing organopolysiloxane by the emulsion polymerization of an acrylic monomer in an aqueous emulsion of the organopolysiloxane. Characteristically, the acrylic monomer is copolymerized with another monomer having an active halogen atom or an epoxy group. By virtue of this unique formulation of the rubbery polymer, the inventive rubber composition prepared by compounding the rubbery polymer with a reinforcing filler and a curing agent can be vulcanized to give a vulcanizate having excellent mechanical properties, heat resistance, oil resistance and cold resistance as a combination of the features of silicone rubbers and acrylic rubbers.
Inventors
- 👤 Kunio Itoh
- 👤 Motoo Fukushima
- 👤 Tsutomu Nakamura
- 👤 Hiroyuki Ohata
- 👤 Harukazu Okuda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 12:44
CPC Classifications
C; C08; C08L; C08L83/00; C08L83/10; C08F; C08F283/00; C08F283/12; C08F283/122; C08K; C08K13/00; C08K13/02; C08L51/00; C08L51/08; C08L51/085
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
227 words
A rubber composition which comprises, in admixture: (a) 100 parts by weight of an organopolysiloxane-modified acrylic copolymer, which is obtained by a process including the steps of (1) emulsifying an organopolysiloxane represented by the average unit formula R a SiO (4-a)/2 , in which R is a substituted or unsubstituted monovalent hydrocarbon group, from 0.0025 to 10% by moles of the groups denoted by R in a molecule being each a monovalent hydrocarbon group substituted with a mercapto group, and the subscript a is a positive number in the range from 1.98 to 2.02, in a aqueous medium to prepare an aqueous emulsion of the organopolysiloxane, (2) adding an acrylic monomer and a second monomer having an active halogen atom or an epoxy group in a molecule and copolymerizable with the acrylic monomer in an amount in the range from 0.1 to 10% by moles based on the acrylic monomer to the aqueous emulsion of the organopolysiloxane, (3) adding a radical polymerization initiator to the aqueous emulsion, and (4) agitating the aqueous emulsion of the organopolysiloxane containing the acrylic monomer, second monomer and radical polymerization initiator to effect copolymerization of the monomers; (b) from 10 to 200 parts by weight of a reinforcing filler having a specific surface area of at least 30 m²/g; and (c) from 0.1 to 10 parts by weight of a crosslinking agent.
Claim 2
Dependent Claim
227 words
A rubber composition which comprises, in admixture: (a) 100 parts by weight of an organopolysiloxane-modified acrylic copolymer, which is obtained by a process including the steps of (1) emulsifying an organopolysiloxane represented by the average unit formula R a SiO (4-a)/2 , in which R is a substituted or unsubstituted monovalent hydrocarbon group, from 0.0025 to 10% by moles of the groups denoted by R in a molecule being each a monovalent hydrocarbon group substituted with a mercapto group, and the subscript a is a positive number in the range from 1.98 to 2.02, in a aqueous medium to prepare an aqueous emulsion of the organopolysiloxane, (2) adding an acrylic monomer and a second monomer having an active halogen atom or an epoxy group in a molecule and copolymerizable with the acrylic monomer in an amount in the range from 0.1 to 10% by moles based on the acrylic monomer to the aqueous emulsion of the organopolysiloxane, (3) adding a radical polymerization initiator to the aqueous emulsion, and (4) agitating the aqueous emulsion of the organopolysiloxane containing the acrylic monomer, second monomer and radical polymerization initiator to effect copolymerization of the monomers; (b) from 10 to 200 parts by weight of a reinforcing filler having a specific surface area of at least 30 m²/g; and (c) from 0.1 to 10 parts by weight of a crosslinking agent.
Claim 3
Dependent Claim
24 words
The rubber composition as claimed in claim 1 wherein the organopolysiloxane-modified acrylic polymer contains from 10 to 90% by weight of the organopolysiloxane moiety.
Claim 4
Dependent Claim
25 words
The rubber composition as claimed in claim 1 wherein the second monomer copolymerizable with the acrylic monomer is a monomer having an active halogen atom.
Claim 5
Dependent Claim
26 words
The rubber composition as claimed in claim 3 wherein the second monomer copolymerizable with the acrylic monomer and having an active halogen atom is vinyl chloroacetate.
Claim 6
Dependent Claim
18 words
The rubber composition as claimed in claim 3 wherein the crosslinking agent is a di- or trithiol-s-triazine compound.
Claim 7
Dependent Claim
18 words
The rubber composition as claimed in claim 1 wherein the reinforcing filler is a finely divided silica filler.
References Cited (Backward Citations)
No citation records indexed.
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