US3852224A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microporous films
Assignee: Continental Group Inc
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Filing: 1972-09-14
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Granted: 1974-12-03
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Expires: 1992-09-14
Abstract
Abstract This invention relates to an improved process for producing a polymer having pores substantially micellar in size and uniformly dispersed throughout the polymer. The formation of the pores is accomplished by incorporating a material in admixture with the polymer, dispersed as micelles, then converting the resultant admixture to a solid phase, and extracting a substantial proportion of the material in micellar form by swelling the solidified polymer with a solvent and converting the micelles to their monomeric constituent. Microporous films prepared in this manner are particularly useful as bacterial filters, binder compositions for ion exchange resins, and the like.
Inventors
- 👤 D Bridgeford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:10
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/26
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
97 words
IN A PROCESS FOR FORMING A MICROPOROUS SOLID POLYMER IN WHICH SAID POLYMER IS SOLIDIFIED IN ADMIXTURE WITH A FINELY DISPERSED POREFORMER WHICH IS SUBSEQUENTLY LEACHED THEREFROM, THE IMPROVEMENT WHICH COMPRISES SOLIDIFYING SAID POLYMER IN ADMIXTURE IN A LIQUID MEDIUM WITH A POREFORMER SURFACTANT MATERIAL FINELY DISPERSED AS MICELLES AND TREATING SAID SOLIDIFIED POLYMER WITH A SOLVENT IN WHICH SAID POLYMER IS SUBSTANTIALLY SWOLLEN AND IN WHICH SAID MICELLES REVERT TO MOLECULAR SIZE WHEREBY THE MICELLAR POREFORMER IS LEACH OUT PRODUCING A MICROPOROUS STRUCTURE COMPRISING A PLURALITY OF PORES OF THE SIZE OF MICELLES OR MICELLE AGGREGATES.
Claim 2
Dependent Claim
97 words
IN A PROCESS FOR FORMING A MICROPOROUS SOLID POLYMER IN WHICH SAID POLYMER IS SOLIDIFIED IN ADMIXTURE WITH A FINELY DISPERSED POREFORMER WHICH IS SUBSEQUENTLY LEACHED THEREFROM, THE IMPROVEMENT WHICH COMPRISES SOLIDIFYING SAID POLYMER IN ADMIXTURE IN A LIQUID MEDIUM WITH A POREFORMER SURFACTANT MATERIAL FINELY DISPERSED AS MICELLES AND TREATING SAID SOLIDIFIED POLYMER WITH A SOLVENT IN WHICH SAID POLYMER IS SUBSTANTIALLY SWOLLEN AND IN WHICH SAID MICELLES REVERT TO MOLECULAR SIZE WHEREBY THE MICELLAR POREFORMER IS LEACH OUT PRODUCING A MICROPOROUS STRUCTURE COMPRISING A PLURALITY OF PORES OF THE SIZE OF MICELLES OR MICELLE AGGREGATES.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein said polymer is formed into a film.
Claim 4
Dependent Claim
14 words
The process of claim 2 wherein said film is formed in a fibrous support.
Claim 5
Dependent Claim
15 words
The process of claim 1 in which said polymer is formed from a polymer precursor.
Claim 6
Dependent Claim
17 words
The process of claim 4 in which said polymer precursor is partially decomposed to produce said polymer.
Claim 7
Dependent Claim
18 words
The process of claim 5 in which said polymer precursor is viscose and said polymer is regenerated cellulose.
Claim 8
Dependent Claim
16 words
The process of claim 4 in which said polymer precursor is hydrolyzed to produce said polymer.
Claim 9
Dependent Claim
26 words
The process of claim 7 in which said polymer precursor is a polyvinyl ester and said polymer is polyvinyl alcohol or a vinyl ester-vinyl alcohol copolymer.
Claim 10
Dependent Claim
13 words
The process of claim 4 in which said polymer is a condensation polymer.
Claim 11
Dependent Claim
13 words
The process of claim 1 in which said polymer is a natural polymer.
Claim 12
Dependent Claim
20 words
The process of claim 1 wherein said polymer is solidified in admixture with said surfactant material and a liquid carrier.
Claim 13
Dependent Claim
12 words
The process of claim 11 wherein said liquid carrier is predominately water.
Claim 14
Dependent Claim
20 words
The process of claim 1 wherein said surfactant material is an anionic surfactant, cationic surfactant, nonionic surfactant, or ampholytic surfactant.
Claim 15
Dependent Claim
31 words
The process of claim 13 wherein said anionic surfactant is an alkyl aromatic sulfate or sulfonate, an alkane or alkene sulfonate, a fatty acid, or a soap of a fatty acid.
Claim 16
Dependent Claim
20 words
The process of claim 13 wherein said cationic surfactant is a quaternary amine salt or a quaternized tertiary amine salt.
Claim 17
Dependent Claim
23 words
The process of claim 13 wherein said nonionic surfactant is a fatty alkyl phenol, an ethoxylated alkyl phenol, or an ethoxylated polyhydric alcohol.
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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) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |