US3862916A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solutions of polyvinyl acetals with phenolic antioxidant in preparation for restoring and/or preserving papers
Assignee: World Patent Development Corp
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Filing: 1973-02-05
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Granted: 1975-01-28
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Expires: 1993-02-05
Abstract
Abstract A stable monophasic composition is here taught consisting of a solution of an antioxidant and copolymers of polyvinyl acetals in a solvent mixture containing a chlorinated hydrocarbon and an aqueous solution of a basic agent. The composition is useful for restoring and preserving papers and similar materials without discoloration.
Inventors
- 👤 Curtis B Hayworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:13
CPC Classifications
D; D21; D21H; D21H25/00; D21H25/18; B; B41; B41M; B41M7/00; B41M7/0063; C; C08; C08K; C08K3/00; C08K3/18; C08K3/20; C08K5/00; C08K5/02; C08K5/04; C08K5/05; C08K5/09; C08K5/13
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
12 words
A composition according to claim 1, wherein the antioxidant is 1,3,5-trimethyl1-2,4,6-tri-(3,5-di-tert-butyl-4-hydroxybenzyl) benzene.
Claim 2
Dependent Claim
12 words
A composition according to claim 2, wherein the chlorinated hydrocarbon is 1,1,2-trichloroethylene.
Claim 3
Dependent Claim
24 words
A composition according to claim 3, wherein the basic agent is selected from a group consisting of barium hydroxide, sodium hydroxide and magnesium acetate.
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) | 1978-01-27 | 1978-07-29 | 1979-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-27 | 1982-07-29 | 1983-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-27 | 1986-07-29 | 1987-01-28 | $7700.00 | Window Closed / Lapsed |