Highly flame-retardant shaped articles and method for preparing the same
Abstract
Abstract Shaped articles such as fibers and films having durable, highly flame-retardant property comprising a halogen-containing polymer and polyvinyl alcohol including its acetal, as principal constituents, and tin substantially in the form of stannic acid. Said shaped articles are produced by a method (A) comprising subjecting shaped articles such as polymer blend fibers containing a halogen-containing polymer and polyvinyl alcohol, as principal constituents, to acetalization in an acetalizing bath containing a tin salt of a strong acid, and converting it to stannic acid substantially afterwards by increase of pH in the articles; alternatively by a method (B) comprising blending an aqueous solution of polyvinyl alcohol, an emulsion of a halogencontaining polymer and an aqueous dispersion of stannic acid or stannic acid anhydride, and subjecting the resulting solution of the polymer blend to emulsion spinning technique; or by a method (C) comprising treating shaped articles such as polymer blend fibers containing, as principal constituents, a halogencontaining polymer and partially acetalized polyvinyl alcohol, with an aqueous solution of a tin salt of a strong acid and converting it to stannic acid substantially afterward by increase of pH in the shaped articles.
Inventors
- 👤 Tadashi Tsuji
- 👤 Mikio Korematsu
Bibliographic Details
Claims Analysis
Total Claims: 3References 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) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |