Patent US2287460A successfully refreshed from Google Patents.
US2840534A
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Method of using ammonium alum in discoloration reduction of foamed vinyl chloride polymers
Assignee: Armstrong World Industries Inc
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Filing: 1956-01-30
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Granted: 1958-06-24
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Expires: 1976-01-30
Abstract
No abstract record available.
Inventors
- 👤 Clark Lawrence
- 👤 Algirdas C Poshkus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:39
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0066; C08K; C08K3/00; C08K3/28; C08L; C08L27/00; C08L27/02; C08L27/04; C08L27/06; C08L9/00; C08L9/02; C08J2327/00; C08J2327/02; C08J2327/04; C08J2327/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
75 words
IN THE METHOD OF FORMING A CELLULAR PRODUCT BY ADMIXING A VINYL CHLORINE POLYMER WITH A BLOWING AGENT AND HEATING THE MIXTURE TO A TEMPERATURE IN THE RANGE OF ABOUT 280*-325*F. SUFFICIENT TO DECOMPOSE THE BLOWING AGENT, THE IMPROVEMENT WHICH COMPRISES INCORPORATING IN SAID MIXTURE BEFORE HEATING AN AMOUNT OF AMMONIUM ALUM IN THE RANGE OF ABOUT 0.5%-7% BY WEIGHT BASED ON THE TOTAL COMPOSITION, SAID AMOUNT BEING EFFECTIVE TO REDUCE DISCOLORATION IN SAID PRODUCT.
Claim 2
Dependent Claim
75 words
IN THE METHOD OF FORMING A CELLULAR PRODUCT BY ADMIXING A VINYL CHLORINE POLYMER WITH A BLOWING AGENT AND HEATING THE MIXTURE TO A TEMPERATURE IN THE RANGE OF ABOUT 280*-325*F. SUFFICIENT TO DECOMPOSE THE BLOWING AGENT, THE IMPROVEMENT WHICH COMPRISES INCORPORATING IN SAID MIXTURE BEFORE HEATING AN AMOUNT OF AMMONIUM ALUM IN THE RANGE OF ABOUT 0.5%-7% BY WEIGHT BASED ON THE TOTAL COMPOSITION, SAID AMOUNT BEING EFFECTIVE TO REDUCE DISCOLORATION IN SAID PRODUCT.
References 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) | 1961-06-23 | 1961-12-23 | 1962-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-23 | 1965-12-23 | 1966-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-23 | 1969-12-23 | 1970-06-24 | $7700.00 | Window Closed / Lapsed |