US4268334A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pipe wrapping adhesive tape method
Assignee: Kendall Co
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Filing: 1979-10-31
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Granted: 1981-05-19
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Expires: 1999-10-31
Abstract
Abstract In a pipe coating made by wrapping the pipe with polyolefin tape and a butyl rubber based adhesive, the strength of the bond to the pipe at elevated temperature is improved by incorporating in the adhesive a cross-linking agent which is either 0.15-1% by weight of p-dinitrosobenzene or 1.0 to 2.5% of p-quinonedioxime, or both together with an activator.
Inventors
- 👤 George M. Harris
- 👤 Samuel J. Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:51
CPC Classifications
F; F16; F16L; F16L58/00; F16L58/02; F16L58/16; B; B65; B65H; B65H81/00; B65H81/06; B65H81/08; C; C08; C08K; C08K5/00; C08K5/16; C08K5/32; C09; C09J; C09J123/00; C09J123/02; C09J123/18; C09J123/20; C09J123/22; C09J7/00; C09J7/20; C09J7/22; C09J7/30; C09J7/38; C08L; C08L2666/00; C08L2666/02; C08L2666/04; C08L2666/28; Y; Y10; Y10S; Y10S138/00; Y10S138/01; Y10T; Y10T428/00; Y10T428/28; Y10T428/2852; Y10T428/2857; Y10T428/2878; Y10T428/2883; Y10T428/31504; Y10T428/31678; Y10T428/31692; Y10T428/31696
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
99 words
In the method of coating steel pipe by wrapping it with a tape comprising a polyolefin backing and an adhesive layer comprising a blend of virgin butyl rubber with reclaimed butyl rubber and a tackifying agent, the procedure for increasing the strength of the adhesive bond which comprises incorporating in the adhesive layer a cross-linking agent selected from the group consisting of (A) 0.15 to 1.0% by weight of p-dinitrosobenzene, (B) 1.0 to 2.5% by weight of p-quinonedioxime, and (C) a mixture of (A) and (B) based on the total weight of said adhesive layer, together with an activator.
Claim 2
Dependent Claim
33 words
The method as claimed in claim 1 in which said virgin butyl rubber has an unsaturation of 0.4 to 2.4%, and the reclaimed butyl rubber has a Mooney viscosity from 40 to 70.
Claim 3
Dependent Claim
23 words
The method as claimed in claim 1 or claim 2 in which said cross-linking agent is 0.15 to 1.0% be weight of p-dinitrosobenzene.
Claim 4
Dependent Claim
42 words
The method as claimed in claim 1 or claim 2 in which said cross-linking agent is 0.15 to 1.0% by weight of p-dinitrosobenzene and said activator is zinc oxide in an amount at least 35 times the weight of said cross-linking agent.
Claim 5
Dependent Claim
23 words
The method as claimed in claim 1 or claim 2 in which said cross-linking agent is 1.0 to 2.5% by weight of p-quinonedioxime.
Claim 6
Dependent Claim
43 words
The method as claimed in claim 1 or claim 2 in which said cross-linking agent is 1.0 to 2.5% by weight of p-quinonedioxime and said activator is red lead oxide in an amount at least 4 times the weight of said cross-linking agent.
Claim 7
Independent Claim
43 words
The method as claimed in claims 1 or 2 including the steps of heating during manufacture said adhesive layer to produce partial cross-linking before said tape is wrapped on said pipe, and completing the cross-linking after said tape is wrapped on said pipe.
References Cited (Backward Citations)
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US2771936A
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US3033724A
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US3258388A
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GB1161117A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-18 | 1984-11-17 | 1985-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-18 | 1988-11-17 | 1989-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-18 | 1992-11-17 | 1993-05-19 | $7700.00 | Window Closed / Lapsed |