US4769426A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparation of polyarylene thioethers having high melt crystallization temperature
Assignee: Kureha Corp
•
Filing: 1986-08-27
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Granted: 1988-09-06
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Expires: 2006-08-27
Abstract
Abstract Polyarylene thioethers having increased melt crystallization temperature are produced by subjecting a polyarylene thioether recovered from a conventional polycondensation of dichlorobenzene with sodium sulfide to a treatment with an aqueous non-oxidative strong acid such asd HCl, H2SO4 or H3PO4 or with an aqueous salt of the non-oxidative strong acid with a weak base such as ammonia.
Inventors
- 👤 Takao Iwasaki
- 👤 Yo Iizuka
- 👤 Toshitaka Kouyama
- 👤 Zenya Shiiki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:56
CPC Classifications
C; C08; C08G; C08G75/00; C08G75/02; C08G75/0204; C08G75/0277; C08G75/0281; C08G75/0286; C08G75/0295; C08G75/0209; C08G75/0213; C08G75/025; C08G75/0254
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
104 words
In a process for the preparation of polyarylene thioethers comprising subjecting an alkali metal sulfide and a dihalo-aromatic compound to dehalogenation/sulfidation in a polar organic solvent to form a polyarylene thioether, the improvement which comprises subjecting the polymer formed separated from the polymerization reaction mixture to a treatment, without causing substantial cure of said polymer with a solution containing 0.1 to 30% by weight of an ammonium salt of hydrochloric acid, sulfuric acid or phosphoric acid at 0° to 100° C. for 5 to 500 minutes thereby to produce a polyarylene thioether having an increased melt crystallization temperature and an increased melt flow rate.
Claim 2
Dependent Claim
104 words
In a process for the preparation of polyarylene thioethers comprising subjecting an alkali metal sulfide and a dihalo-aromatic compound to dehalogenation/sulfidation in a polar organic solvent to form a polyarylene thioether, the improvement which comprises subjecting the polymer formed separated from the polymerization reaction mixture to a treatment, without causing substantial cure of said polymer with a solution containing 0.1 to 30% by weight of an ammonium salt of hydrochloric acid, sulfuric acid or phosphoric acid at 0° to 100° C. for 5 to 500 minutes thereby to produce a polyarylene thioether having an increased melt crystallization temperature and an increased melt flow rate.
Claim 3
Dependent Claim
32 words
The process for the preparation of polyarylene thioethers according to claim 1 wherein the polymer separated from the polymerization mixture with the polar organic solvent adhering thereto is subjected to the treatment.
Claim 4
Dependent Claim
55 words
The process for the preparation of polyarylene thioethers according to claim 1 wherein the polymer separated from the polymerization mixture with the polar organic solvent adhering thereto is washed with a solvent in which the polar organic solvent dissolves, and the polymer thus washed with the washing solvent adhering thereto is subjected to the treatment.
Claim 5
Dependent Claim
18 words
The process for the preparation of polyarylene thioethers according to claim 1 wherein the salt is ammonium chloride.
References Cited (Backward Citations)
US3839301A
Cited
US3879355A
Cited
US3948865A
Cited
US4251575A
Cited
US4038262A
Cited
US4025496A
Cited
US4237039A
Cited
US4373091A
Cited
EP0087038A1
Cited
US4495332A
Cited
US4490522A
Cited
US4424338A
Cited
US4524200A
Cited
US4514558A
Cited
US4537951A
Cited
JPS59202222A
Cited
EP0126369A1
Cited
US4537953A
Cited
EP0142024A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-06 | 1992-03-07 | 1992-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-06 | 1996-03-07 | 1996-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-06 | 2000-03-07 | 2000-09-06 | $7700.00 | Window Closed / Lapsed |