US3628996A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polydimethylsiloxane release agent
Assignee: Dow Silicones Corp
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Filing: 1969-06-27
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Granted: 1971-12-21
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Expires: 1989-06-27
Abstract
Abstract Release agents which give superior release against aggressive adhesives are made by mixing (1) a hydroxyl endblocked polydimethylsiloxane having a viscosity of at least 350 cs. and (2) either from 25 to 75 percent by weight of a triorganosiloxy endblocked dimethylpolysiloxane or from 10 to 75 percent by weight of a polydimethylsiloxane having a triorganosiloxy group on one end and a hydroxyl on the other, (2) having a viscosity of at least 4000 cs. at 25* C. and (3) a cross-linker for (1).
Inventors
- 👤 Carl D Weber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:38
CPC Classifications
C; C08; C08L; C08L83/00; C08L83/04; C08G; C08G77/00; C08G77/04; C08G77/14; C08G77/16
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
11 words
The method of claim 1, in which the substrate is paper.
Claim 2
Dependent Claim
72 words
from 25 to 75 percent by weight based on the combined weight of (1) and (2) of a benzene soluble dimethylpolysiloxane having triorganosiloxy groups on both ends of the molecule or from 10 to 75 percent by weight based on the weight of (1) and (2) of a dimethylpolysiloxane having triorganosiloxy groups on one end of the molecule and hydroxyls on the other, (2) having viscosity of at least 4,000 cs., and
Claim 3
Dependent Claim
24 words
a cross-linker for (1), the organic groups in said triorganosiloxy groups being monovalent hydrocarbon or halohydrocarbon groups of from one to 12 carbon atoms.
Claim 4
Dependent Claim
14 words
The method of claim 1 in which the substrate is a flexible organic sheet.
Claim 5
Dependent Claim
12 words
The method of claim 1 in which the cross-linker is methylhydrogen siloxane.
Claim 6
Dependent Claim
24 words
The method of claim 4 in which the film is cured using a tin salt of a carboxylic acid or a mercapto tin salt.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-20 | 1975-06-21 | 1975-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-20 | 1979-06-21 | 1979-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-20 | 1983-06-21 | 1983-12-21 | $7700.00 | Window Closed / Lapsed |