US2638465A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copolymers of styrene and alphamethyl styrene and process for making the same
Assignee: Dow Chemical Co
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Filing: 1950-01-03
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Granted: 1953-05-12
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Expires: 1970-01-03
Abstract
No abstract record available.
Inventors
- 👤 James L Amos
- 👤 Carroll T Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:17
CPC Classifications
C; C08; C08F; C08F212/00; C08F212/02; C08F212/04; C08F212/06; C08F212/12; C08F212/08; C08F6/00; C08F6/001; C08F6/005
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
52 words
A PROCESS FOR MAKING A COPOLYMER A STYRENE AND ALPHA-METHYL STYRENE WHICH COMPRISES HEATING A MIXTURE CONSISTING OF FROM 10 TO 50 PER CENT BY WEIGHT OF ALPHA-METHYL STYRENE AND FROM 90 TO 50 PER CENT OF STYRENE IN BULK TO A POLYMERIZATION TEMPERATURE NOT GREATER THAN THAT DEFINED BY THE EQUATION:
Claim 2
Dependent Claim
52 words
A PROCESS FOR MAKING A COPOLYMER A STYRENE AND ALPHA-METHYL STYRENE WHICH COMPRISES HEATING A MIXTURE CONSISTING OF FROM 10 TO 50 PER CENT BY WEIGHT OF ALPHA-METHYL STYRENE AND FROM 90 TO 50 PER CENT OF STYRENE IN BULK TO A POLYMERIZATION TEMPERATURE NOT GREATER THAN THAT DEFINED BY THE EQUATION:
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) | 1956-05-11 | 1956-11-10 | 1957-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-11 | 1960-11-10 | 1961-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-11 | 1964-11-10 | 1965-05-12 | $7700.00 | Window Closed / Lapsed |