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US4463118A Expired / Lapsed US ⏱️ 0.0 years remaining

Oil extended silicone elastomer composition

Assignee: General Electric Co
•
Filing: 1981-07-16
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Granted: 1984-07-31
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Expires: 2001-07-16
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Abstract

Abstract A heat curable oil extended silicone elastomer composition and the cured silicone elastomers derived therefrom which exhibit improved melt flow and improved tear resistance at high filler loadings. A preferred composition comprises in admixture, a silarylenesiloxane polydiorganosiloxane block copolymer, a dimethylsilicone oil bearing vinyl-type unsaturation, a filler and a catalyst.

Inventors

  • 👤 Edwin R. Evans
  • 👤 John S. Razzano

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 18:26
CPC Classifications
C; C08; C08L; C08L83/00; C08L83/10; C08L83/14

Claims Analysis

Total Claims: 30
Claim 1
Independent Claim 34 words
A curable silicone elastomer composition blend consisting essentially of a silarylenesiloxane copolymer, a dimethylsilicone oil bearing vinyl-type unsaturation for effecting cross-linking of said silarylenesiloxane copolymers with said dimethylsilicone oil, a catalyst and a filler.
Claim 2
Dependent Claim 34 words
A curable silicone elastomer composition blend consisting essentially of a silarylenesiloxane copolymer, a dimethylsilicone oil bearing vinyl-type unsaturation for effecting cross-linking of said silarylenesiloxane copolymers with said dimethylsilicone oil, a catalyst and a filler.
Claim 3
Dependent Claim 91 words
The composition of claim 1, wherein the silarylenesiloxane is a silarylenesiloxane-polydiorganosiloxane block copolymer made up of units of silarylenesiloxane having the general formula: ##STR3## and diorganopolysiloxane of the general formula: ##STR4## wherein n is an integer equal to 1 to about 100, R is a divalent aromatic organic radical, R 1 is a monovalent organic radical, a is an integer equal to from about 5 to about 10,000 inclusive, and R 2 is an organic radical selected from the group consisting of monovalent hydrocarbon radicals, unsaturated aliphatic radicals and halogenated radicals.
Claim 4
Dependent Claim 26 words
The composition of claim 2, wherein R 2 is selected from the group consisting of methyl radicals, ethyl radicals, and combinations of methyl and ethyl radicals.
Claim 5
Dependent Claim 20 words
The composition of claims 2 or 3, wherein R is a phenylene radical and R 1 is a methyl radical.
Claim 6
Dependent Claim 24 words
The composition of claim 2, wherein a has a value of about 26 and n has a value from about 4 to about 6.
Claim 7
Dependent Claim 16 words
The composition of claim 1, wherein the dimethylsilicone oil contains a low level of vinyl-type unsaturation.
Claim 8
Dependent Claim 36 words
The composition of claims 1 or 6 wherein the dimethylsilicone oils have a level of vinyl-type unsaturation in the range of about 0.05 mole percent vinyl to about 0.7 mole percent vinyl based on silarylenesiloxane copolymer.
Claim 9
Dependent Claim 19 words
The composition of claim 1, wherein the dimethylsilicone oil has a viscosity of about 500 to about 25,000 centistokes.
Claim 10
Dependent Claim 28 words
The composition of claim 1, wherein the dimethylsilicone oil is present in an amount from about 1 to about 40 parts per hundred parts of the silarylenesiloxane copolymers.
Claim 11
Dependent Claim 28 words
The composition of claim 1, wherein the dimethylsilicone oil is present in an amount from about 5 to about 10 parts per hundred parts of the silarylenesiloxane copolymer.
Claim 12
Dependent Claim 31 words
The composition of claim 1, wherein the dimethylsilicone oil has a level of vinyl-type unsaturation of about 0.5 to about 0.6 mole percent and has a viscosity of about 20,000 centistokes.
Claim 13
Dependent Claim 25 words
The composition of claim 1, wherein the dimethylsilicone oil has a level of vinyl-type unsaturation of about 0.6 mole percent and of about 700 centistokes.
Claim 14
Dependent Claim 27 words
The composition of claim 1, wherein the catalyst is present in an amount from about 0.1 to about 10.0 parts per hundred parts of the silarylenesiloxane copolymer.
Claim 15
Dependent Claim 27 words
The composition of claim 1, wherein the catalyst is present in an amount from about 0.2 to about 2.0 parts per hundred parts of the silarylenesiloxane copolymer.
Claim 16
Dependent Claim 15 words
The composition of claims 1, 13 or 14, wherein the catalyst is an organotertiary peroxide.
Claim 17
Dependent Claim 16 words
The composition of claims 13 or 14, wherein the organotertiary peroxide catalyst is dicumylperoxide or α,α'-bis(t-butylperoxy)diisopropylbenzene.
Claim 18
Dependent Claim 25 words
The composition of claim 1, wherein the filler is present in an amount up to about 80 parts per hundred parts of the silarylenesiloxane copolymer.
Claim 19
Dependent Claim 13 words
The composition of claims 1 or 17, wherein the filler is fumed silica.
Claim 20
Dependent Claim 6 words
The cured composition of claim 1.
Claim 21
Dependent Claim 37 words
A silicone elastomer composition blend consisting essentially of a silarylenesiloxane copolymer, a dimethyl silicone oil bearing a low level of vinyl-type unsaturation, a catalyst, a filler, and a dimethyl silicone oil bearing a high level vinyl-type unsaturation.
Claim 22
Dependent Claim 37 words
A silicone elastomer composition blend consisting essentially of a silarylenesiloxane copolymer, a dimethyl silicone oil bearing a low level of vinyl-type unsaturation, a catalyst, a filler, and a dimethyl silicone oil bearing a high level vinyl-type unsaturation.
Claim 23
Dependent Claim 21 words
The composition of claim 20 wherein the dimethyl silicone oil bearing a high level of vinyl is a dimethyl silicone gum.
Claim 24
Independent Claim 57 words
A method of preparing silicone elastomer composition blends consisting essentially of curing a mixture of silarylenesiloxane copolymer, a dimethyl silicone oil bearing a low level of vinyl-type unsaturation, a catalyst and optionally, a filler; adding a dimethyl silicone oil bearing a high level of vinyl-type unsaturation to the cured blend; and post-curing the mixture by additional heating.
Claim 25
Independent Claim 57 words
A method of preparing silicone elastomer composition blends consisting essentially of curing a mixture of silarylenesiloxane copolymer, a dimethyl silicone oil bearing a low level of vinyl-type unsaturation, a catalyst and optionally, a filler; adding a dimethyl silicone oil bearing a high level of vinyl-type unsaturation to the cured blend; and post-curing the mixture by additional heating.
Claim 26
Dependent Claim 61 words
The method of claim 22 consisting essentially of heating the mixture at about 100° C. to about 200° C. for about 5 minutes to about 2.0 hours to cure the copolymer and heating the cured copolymer containing the additional extender material at about 150° C. to about 275° C. for about 5 minutes to about 2.0 hours to post-cure the copolymer.
Claim 27
Dependent Claim 28 words
A curable silicone elastomer composition blend consisting essentially of a silarylenesiloxane copolymer a dimethylsilicone oil bearing a high level of vinyl-type unsaturation, a catalyst and, optionally, a filler.
Claim 28
Dependent Claim 28 words
A curable silicone elastomer composition blend consisting essentially of a silarylenesiloxane copolymer a dimethylsilicone oil bearing a high level of vinyl-type unsaturation, a catalyst and, optionally, a filler.
Claim 29
Dependent Claim 89 words
The composition of claim 24, wherein the silarylenesiloxane is a silarylenesiloxane-polydiorganosiloxane block copolymer made up of units of silarylenesiloxane having the general formula: ##STR5## and diorganopolysiloxane of the general formula: ##STR6## wherein n is an integer equal to about 100, R is a divalent aromatic organic radical, R 1 is a monovalent organic radical, a is an integer equal to from about 5 to about 10,000 inclusive, and R 2 is an organic radical selected from the group consisting of monovalent hydrocarbon radicals, unsaturated aliphatic radicals and halogenated radicals.
Claim 30
Dependent Claim 34 words
The composition of claim 24 wherein the dimethylsilicone oils have a level of vinyl-type unsaturation in the range of about 0.6 mole percent vinyl to about 13.5 mole percent vinyl based on silarylenesiloxane copolymer.

References Cited (Backward Citations)

US3109826A Cited
US3202634A Cited
US3696068A Cited
US3779987A Cited
US3853805A Cited
US3959403A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-07-31 1988-01-30 1988-07-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-07-31 1992-01-30 1992-07-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-07-31 1996-01-30 1996-07-31 $7700.00 Window Closed / Lapsed

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