US4274993A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moldable polyphenylenesulfide
Assignee: AGC Inc
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Filing: 1979-05-30
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Granted: 1981-06-23
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Expires: 1999-05-30
Abstract
Abstract A moldable polyphenylenesulfide is obtained by a heat-treatment of a partially crosslinked or noncrosslinked polyphenylenesulfide at a temperature of higher than 290 DEG C. in an atmosphere being substantially absence of oxygen.
Inventors
- 👤 Shigeyuki Narisawa
- 👤 Hiroshi Yanase
- 👤 Fukuo Kanno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:08
CPC Classifications
C; C08; C08G; C08G75/00; C08G75/02; C08G75/0204; C08G75/0277; C08G75/0286; C08G75/0295
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
52 words
A moldable polyphenylenesulfide for injection or extrusion molding obtained by heat-treating a partially cross-linked polyphenylenesulfide at a temperature greater than 290° C. in an atmosphere substantially free of oxygen, said partially cross-linked polyphenylenesulfide being obtained by heating noncrosslinked polyphenylenesulfide at a temperature lower than its melting point in the presence of oxygen.
Claim 2
Dependent Claim
52 words
A moldable polyphenylenesulfide for injection or extrusion molding obtained by heat-treating a partially cross-linked polyphenylenesulfide at a temperature greater than 290° C. in an atmosphere substantially free of oxygen, said partially cross-linked polyphenylenesulfide being obtained by heating noncrosslinked polyphenylenesulfide at a temperature lower than its melting point in the presence of oxygen.
Claim 3
Dependent Claim
19 words
The moldable polyphenylenesulfide according to claim 1 wherein said atmosphere substantially free of oxygen is a reduced pressure atmosphere.
Claim 4
Dependent Claim
29 words
The moldable polyphenylenesulfide according to claim 1 wherein the atmosphere substantially free of oxygen is an inert gas atmosphere having an oxygen partial pressure of less than 2 mmHg.
Claim 5
Dependent Claim
20 words
The moldable polyphenylenesulfide according to claim 1 wherein the temerature for the heat-treatment ranges from 310° C. to 500° C.
Claim 6
Dependent Claim
32 words
The moldable polyphenylenesulfide according to claim 1 wherein the weight loss of the treated polyphenylenesulfide measured by heating at 300° C. for 120 minutes in vacuum is less than 0.3 wt. %.
Claim 7
Dependent Claim
27 words
The moldable polyphenylenesulfide according to claim 2, 3, 4, 5, or 1 wherein a filler is incorporated in said partially crosslinked polyphenylenesulfide before or after the heat-treatment.
Claim 8
Dependent Claim
13 words
The moldable polyphenylenesulfide according to claim 6 wherein the filler is glass fiber.
Claim 9
Dependent Claim
27 words
The moldable polyphenylenesulfide according to claim 6, wherein said filler is incorporated in said partially crosslinked polyphenylenesulfide in an amount of up to about 80 weight percent.
Claim 10
Dependent Claim
73 words
The moldable polyphenylenesulfide according to claim 1, wherein said partially crosslinked polyphenylenesulfide is obtained by heating a noncrosslinked polypheneylenesulfide at a temperature lower than its melting point in the presence of oxygen to achieve the desired degree of crosslinking, and then heating said partially crosslinked polyphenylenesulfide at a temperature higher than its melting point in a vacuum or under an inert gas atmosphere to prevent further substantial crosslinking of said partially crosslinked polyphenylenesulfide.
Claim 11
Dependent Claim
24 words
A molded polyphenylenesulfide which is obtained by injection molding or extrusion molding of the moldable polyphenylenesulfide of claim 2, 3, 4, 5 or 1.
Claim 12
Dependent Claim
27 words
The moldable polyphenylenesulfide according to claim 1, wherein said moldable polyphenylenesulfide has an apparent viscosity at 330° C. under a load of 20 kg/cm 2 >500 poises.
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) | 1984-06-22 | 1984-12-22 | 1985-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-22 | 1988-12-22 | 1989-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-22 | 1992-12-22 | 1993-06-23 | $7700.00 | Window Closed / Lapsed |