US2972170A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methyl methacrylate monomer molding process
Assignee: Birckhead Corp
•
Filing: 1957-06-17
•
Granted: 1961-02-21
•
Expires: 1977-06-17
Abstract
No abstract record available.
Inventors
- 👤 Jr Lennox Birckhead
- 👤 Taylor A Birckhead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:26
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/0001
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
86 words
A METHOD OF FORMING POLYMERIZED METHYL METHACRYLATE MOLDINGS INCLUDING THE STEPS OF MIXING FINELY DIVIDED METHYL METHACRYLATE POLYMER HAVING AN AVERAGE PARTICLE DIAMETER BETWEEN 24 MILS AND 3 MILS WITH SUFFICIENT METHYL METHACRYLATE MONOMER TO PRODUCE A FLOWABLE MIXTURE IN WHICH THE POLYMER PARTICLES ARE SWELLED BUT ARE NOT DISSOLVED, INTRODUCING THE MIXTURE INTO A MOLD AND THERE GELLING THE SAME AT A TEMPERATURE BETWEEN 165* F. AND 183*F. FOR A TIME BETWEEN 35 MINUTES AND 7 MINUTES, THEN RAISING THE TEMPERATURE OF THE GELLED MASS
Claim 2
Independent Claim
86 words
A METHOD OF FORMING POLYMERIZED METHYL METHACRYLATE MOLDINGS INCLUDING THE STEPS OF MIXING FINELY DIVIDED METHYL METHACRYLATE POLYMER HAVING AN AVERAGE PARTICLE DIAMETER BETWEEN 24 MILS AND 3 MILS WITH SUFFICIENT METHYL METHACRYLATE MONOMER TO PRODUCE A FLOWABLE MIXTURE IN WHICH THE POLYMER PARTICLES ARE SWELLED BUT ARE NOT DISSOLVED, INTRODUCING THE MIXTURE INTO A MOLD AND THERE GELLING THE SAME AT A TEMPERATURE BETWEEN 165* F. AND 183*F. FOR A TIME BETWEEN 35 MINUTES AND 7 MINUTES, THEN RAISING THE TEMPERATURE OF THE GELLED MASS
References Cited (Backward Citations)
US2045651A
Cited
US2207822A
Cited
US2234993A
Cited
US2347320A
Cited
US2284335A
Cited
US2370562A
Cited
US2497451A
Cited
US2548438A
Cited
US2559345A
Cited
US2806822A
Cited
US2762784A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-02-21 | 1964-08-22 | 1965-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-02-21 | 1968-08-22 | 1969-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-02-21 | 1972-08-22 | 1973-02-21 | $7700.00 | Window Closed / Lapsed |