US3914191A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methyl format E-trichloromonofluoromethane blowing agent for polystyrene
Assignee: Lyondell Chemical Technology LP
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Filing: 1974-07-31
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Granted: 1975-10-21
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Expires: 1994-07-31
Abstract
Abstract This invention relates to the use of a methyl formatetrichloromonofluoromethane azeotrope as a blowing agent in producing polystyrene foam.
Inventors
- 👤 Robert J Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:27
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/12; C08J9/14; C08J9/149; C08J2203/00; C08J2203/12; C08J2203/14; C08J2203/142; C08J2325/00; C08J2325/02; C08J2325/04; C08J2325/06; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S521/00; Y10S521/908; Y10S521/91
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
69 words
A PROCESS FOR PRODUCING POLYSTYRENE FOAM WHICH COMPRISES (1) FORMING A MIXTURE OF (A) A MAJOR AMOUNT OF POLYSTYRENE AND (B) MINOR AMOUNT OF A LIQUID AZEOTROPE CONSISTING OF 18 PARTS BY WEIGHT OF METHYL FORMATE AND 82 PARTS BY WEIGHT OF TRICHLOROMONOFLUOROMETHANE PER 100 PARTS BY WEIGHT OF THE AZEOTROPE AND (I) MAINING THE MIXTURE AT A TEMPERATURE AT WHICH THE AZEOTROPE VOLATILIZES TO PRODUCE A POLYSTYRENE FOAM.
Claim 2
Dependent Claim
69 words
A PROCESS FOR PRODUCING POLYSTYRENE FOAM WHICH COMPRISES (1) FORMING A MIXTURE OF (A) A MAJOR AMOUNT OF POLYSTYRENE AND (B) MINOR AMOUNT OF A LIQUID AZEOTROPE CONSISTING OF 18 PARTS BY WEIGHT OF METHYL FORMATE AND 82 PARTS BY WEIGHT OF TRICHLOROMONOFLUOROMETHANE PER 100 PARTS BY WEIGHT OF THE AZEOTROPE AND (I) MAINING THE MIXTURE AT A TEMPERATURE AT WHICH THE AZEOTROPE VOLATILIZES TO PRODUCE A POLYSTYRENE FOAM.
Claim 3
Dependent Claim
78 words
An extrusion process for producing polystyrene foam which comprises introducing crystalline particulate polystyrene into an extruder, melting the polystyrene in the extruder at superatmospheric pressure, injecting into the melted polystyrene a minor amount of a liquid azeotrope consisting of 18 parts by weight of methyl formate and 82 parts by weight of trichloromonofluoromethane per 100 parts by weight of the azeotrope to form a polystyrene-azeotrope mixture and passing the mixture through a die to produce a polystyrene foam.
Claim 4
Dependent Claim
78 words
An extrusion process for producing polystyrene foam which comprises introducing crystalline particulate polystyrene into an extruder, melting the polystyrene in the extruder at superatmospheric pressure, injecting into the melted polystyrene a minor amount of a liquid azeotrope consisting of 18 parts by weight of methyl formate and 82 parts by weight of trichloromonofluoromethane per 100 parts by weight of the azeotrope to form a polystyrene-azeotrope mixture and passing the mixture through a die to produce a polystyrene foam.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |