US4098969A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Product and process for preparing polyvinyl alcohol deposits of reduced water sensitivity
Assignee: Hoechst AG
•
Filing: 1976-07-01
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Granted: 1978-07-04
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Expires: 1996-07-01
Abstract
Abstract The water resistance of compositions containing polyvinyl alcohol as binder is considerably increased by incorporating therein boric acid and a buffer or a compound which on heating irreversibly reacts to render the mixture alkaline. Sodium trichloro acetate is especially suitable.
Inventors
- 👤 Wolfgang Zimmermann
- 👤 Hermann Schindler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 08:09
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/42
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
101 words
A process for reducing the water sensitivity of polyvinyl alcohol which comprises preparing a mixture containing polyvinyl alcohol and boric acid in aqueous solution and a buffer which at room temperature maintains the solution at a pH not exceeding 7 and which on heating only is altered irreversibly to cause the pH of the solution to shift to the alkaline range, said buffer being a compound selected from alkali metal and alkaline earth metal salts of trichloroacetic and tribromoacetic acids, and heating said mixture to a temperature sufficient to render it alkaline and decrease the water sensitivity of said polyvinyl alcohol.
Claim 2
Dependent Claim
101 words
A process for reducing the water sensitivity of polyvinyl alcohol which comprises preparing a mixture containing polyvinyl alcohol and boric acid in aqueous solution and a buffer which at room temperature maintains the solution at a pH not exceeding 7 and which on heating only is altered irreversibly to cause the pH of the solution to shift to the alkaline range, said buffer being a compound selected from alkali metal and alkaline earth metal salts of trichloroacetic and tribromoacetic acids, and heating said mixture to a temperature sufficient to render it alkaline and decrease the water sensitivity of said polyvinyl alcohol.
Claim 3
Dependent Claim
12 words
A process according to claim 1 wherein said buffer is sodium trichloroacetate.
References Cited (Backward Citations)
US2716049A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-03 | 1982-01-02 | 1982-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-03 | 1986-01-02 | 1986-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-03 | 1990-01-02 | 1990-07-04 | $7700.00 | Window Closed / Lapsed |