US3925323A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Poly(meta-phenylene isophthalamide)powder
Assignee: EIDP Inc
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Filing: 1972-06-14
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Granted: 1975-12-09
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Expires: 1992-06-14
Abstract
Abstract A poly(meta-phenylene isophthalamide) powder is provided which is coalescible under the influence of pressure followed by heating at temperatures below its crystalline melting point to provide molded objects of a solid and homogeneous nature. A process for preparing coalescible powders of poly(meta-phenylene isophthalamide) also is provided wherein a solution of said polymer in a solvent such as DMAC is added to a precipitant such as water to provide a slurry which is filtered, followed by washing and drying the resulting filter cake to provide a crumb which is ground and screened through a sieve of 35 mesh size (U.S. Standard).
Inventors
- 👤 John William Turnbull
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:24
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/14; B; B29; B29C; B29C43/00; B29C43/003; B29C43/006; C08L; C08L77/00; C08L77/10; B29K; B29K2077/00; B29K2077/10; B29K2105/00; B29K2105/25; B29K2105/251; C08J2377/00; C08J2377/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
122 words
A COALESCIBLE AND DENSIDIABLE POWER OF POLY(META-PHENYLENE ISOPTHALAMIDE) CHARACTERIZED BY A DENSITY OF AT LEAST ABOUT 1.0 G. CC. WHEN PRESSED INTO A PERFORM AND A DENSITY WHEN SINTERED OF AT LEAST ABOUT 1.24 G. CC. PRODUCED BY ADDING A SOLUTION OF BETWEEN ABOUT 0.5 AND ABOUT 3.5 PERCENT BY WEIGHT, BASED UPON THE TOTAL WEIGHT OF SAID SOLUTION, OF POLY(META-PHENYLENE ISOPTHALAMIDE) IN A SOLVENT SELECTED FROM ANY OF THE GROUP CONSISTING OF DIMETHYLFORMAMIDE AND DIMETHYLACETAMIDE TO WATER TO FORM A SLURRY AND AGITATING SAID SLURRY AND THEREAFTER FILTERING SAID SLURRY TO RECOVER SOLID PARTICLES OF SAID POLY(META-PHENYLENE ISOPHTHALAMIDE), AND WASHING AND DRYING SAID SOLID PARTICLES AND COMMINUTING SAID SOLID PARTICLES WHEREBY TO PROVIDE SAID COALESCIBLE AND DENSIFIABLE POWDER OF POLY(META-PHENYLENE ISOPHTHALAMIDE).
Claim 2
Dependent Claim
122 words
A COALESCIBLE AND DENSIDIABLE POWER OF POLY(META-PHENYLENE ISOPTHALAMIDE) CHARACTERIZED BY A DENSITY OF AT LEAST ABOUT 1.0 G. CC. WHEN PRESSED INTO A PERFORM AND A DENSITY WHEN SINTERED OF AT LEAST ABOUT 1.24 G. CC. PRODUCED BY ADDING A SOLUTION OF BETWEEN ABOUT 0.5 AND ABOUT 3.5 PERCENT BY WEIGHT, BASED UPON THE TOTAL WEIGHT OF SAID SOLUTION, OF POLY(META-PHENYLENE ISOPTHALAMIDE) IN A SOLVENT SELECTED FROM ANY OF THE GROUP CONSISTING OF DIMETHYLFORMAMIDE AND DIMETHYLACETAMIDE TO WATER TO FORM A SLURRY AND AGITATING SAID SLURRY AND THEREAFTER FILTERING SAID SLURRY TO RECOVER SOLID PARTICLES OF SAID POLY(META-PHENYLENE ISOPHTHALAMIDE), AND WASHING AND DRYING SAID SOLID PARTICLES AND COMMINUTING SAID SOLID PARTICLES WHEREBY TO PROVIDE SAID COALESCIBLE AND DENSIFIABLE POWDER OF POLY(META-PHENYLENE ISOPHTHALAMIDE).
Claim 3
Dependent Claim
31 words
The poly(meta-phenylene isophthalamide) powder of claim 1 wherein said densifiable powder has an apparent bulk density of at least about 0.10 g./cc., and a surface area greater than about 40 m.2/g.
Claim 4
Dependent Claim
24 words
The poly(meta-phenylene isophthalamide powder of claim 1 wherein said solid particles of poly(meta-phenylene isophthalamide) are dried at a temperature of up to about 250*C.
Claim 5
Dependent Claim
16 words
The poly(meta-phenylene isophthalamide) powder of claim 1 wherein said solid particles are dried at reduced pressure.
Claim 6
Dependent Claim
82 words
A shaped article consisting essentially of coalesced and densifiable solid particles of poly(meta-phenylene isophthalamide) having a density of at least about 1.24 g./cc. produced by pressing a coalescible and densifiable powder of claim 1 by subjecting said powder to a forming pressure of at least 10,000 psi to provide a preform having a density of at least about 1.0 g./cc. and sintering said preform by heating said preform to a temperature between about 250* and about 350*C. to provide said shaped article.
Claim 7
Dependent Claim
16 words
The shaped article of claim 5 having a tensile strength oF at least about 13,000 psi.
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) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |