Patent US3674735A successfully refreshed from Google Patents.
US3674735A
Expired / Lapsed
US
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Semi-vulcanized butyl rubber for sealant applications
Assignee: Cities Service Co
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Filing: 1969-12-22
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Granted: 1972-07-04
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Expires: 1989-12-22
Abstract
Abstract Semi-vulcanized butyl rubber compounds having a Mooney viscosity (ML-3 at 260* F) of about 30 to about 80 are produced by curing a mixture of butyl rubber, a plasticizer and a vulcanizing agent, the latter being employed in an amount that is insufficient for complete vulcanization of the rubber. The resultant semivulcanized compounds are readily processible during the formulation of sealant caulks and tapes and are further characterized by good dimensional stability which results from reduced flow of the compound.
Inventors
- 👤 John E Callan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:40
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/24; C08J2323/00; C08J2323/02; C08J2323/18; C08J2323/20; C08J2323/22
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
28 words
The method of claim 1 in which the rubber is semi-vulcanized within about 1 to about 4 minutes at a temperature of from about 250*F to about 350*F.
Claim 2
Dependent Claim
29 words
The method of claim 1 wherein said vulcanizing agent is first incorporated with said plasticizer and the mixture of these two is then mixed with said butyl rubber cement.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein the plasticizer for the butyl rubber is selected from the group consisting of non-aromatic extender oils, low molecular weight polybutene, and mixtures thereof.
Claim 4
Dependent Claim
34 words
The method of claim 1 wherein the amount of plasticizer employed in the mixture is within the range of about 10 to about 40 parts, by weight, per 100 parts of the butyl rubber.
Claim 5
Dependent Claim
14 words
The method of claim 1 wherein the vulcanizing agent is a halogenated phenolic resin.
Claim 6
Dependent Claim
12 words
The method of claim 1 wherein the vulcanizing agent is p-quinone dioxime.
Claim 7
Dependent Claim
25 words
The method of claim 1 wherein the Mooney viscosity of the semi-vulcanized butyl rubber compound is within the range of about 40 to about 60.
Claim 8
Dependent Claim
30 words
The method of producing a butyl sealing tape or caulk which comprises mixing the semi-vulcanized butyl rubber compound produced in claim 1 with at least one other rubber compounding ingredient.
Claim 9
Dependent Claim
13 words
The method of claim 9 wherein said compounding ingredient is a rubber filler.
Claim 10
Dependent Claim
13 words
The method of claim 9 wherein said compounding ingredient is a rubber extender.
Claim 11
Dependent Claim
13 words
The method of claim 9 wherein said compounding ingredient is a rubber tackifier.
Claim 12
Dependent Claim
172 words
The method of claim 9 wherein said compounding ingredient is a solvent for the rubber. 14 The method of producing a butyl rubber compound comprising: a. coating the particles of an inert, pulverulent carrier material with a plasticizer for butyl rubber and a vulcanizing agent for butyl rubber, b. coating crumbs of butyl rubber with the resulting coated particles of said carrier material, the amount of said vulcanizing agent thus added to said rubber being sufficient for only partial vulcanization thereof, and the amount of plasticizer thus added to the rubber being sufficient to impart thereto a Mooney viscosity (ML-3'' at 260*F.) of about 15 to about 25 upon incorporation of said plasticizer in said rubber, c. subsequently masticating the resulting coated crumbs of butyl rubber in the presence of heat, thus incorporating said plasticizer and vulcanizing agent with the rubber and also partially vulcanizing said butyl rubber during the mastication, and d. recovering a semi-vulcanized butyl rubber characterized by a Mooney viscosity (ML-3'' at 260*F.) of about 30 to about 80.
Claim 13
Dependent Claim
14 words
The method of claim 14 wherein the crumbs of butyl rubber are dry crumbs.
Claim 14
Dependent Claim
14 words
The method of claim 14 wherein the crumbs of butyl rubber are wet crumbs.
Claim 15
Dependent Claim
29 words
The method of claim 14 in which the butyl rubber is semi-vulcanized within about 1 to about 4 minutes at a temperature of from about 250*F to about 450*F.
Claim 16
Dependent Claim
26 words
The method of claim 17 in which the coated crumbs of butyl rubber are masticated and the rubber is cured by passage through a heated extruder.
Claim 17
Dependent Claim
26 words
The method of claim 14 in which the Mooney viscosity of the semi-vulcanized butyl rubber compound is within the range of about 40 to about 60.
Claim 18
Dependent Claim
27 words
The method of claim 14 wherein said coated carrier particles are in the form of a powder and said butyl rubber crumbs are coated with said powder.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |