US3714307A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aqueous coagulation of salt containing polyurethane to form porous sheet
Assignee: Kanegafuchi Spinning Co Ltd
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Filing: 1971-02-24
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Granted: 1973-01-30
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Expires: 1991-02-24
Abstract
Abstract The process for producing a porous sheet material comprises the steps of applying a coating solution to at least one surface of a fibrous base or a film-making plate to form a coating layer. The coating layer is then coagulated and regenerated. The coating solution contains a water-miscible organic solvent, a polyurethane polyester and at least one inorganic salt. The aqueous medium comprises an aqueous solution of said inorganic salt in a concentration of below about two thirds its concentration at saturation and at least sufficient to yield a porous sheet. The coating solution comprises 10 to 50 parts by weight of inorganic salt in 100 parts by weight of a film forming polyester type polyurethane.
Inventors
- 👤 T Shikada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:27
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; B; B29; B29C; B29C67/00; B29C67/20; B29C67/202; D; D06; D06N; D06N3/00; D06N3/0043; D06N3/0052; C08J2375/00; C08J2375/04; Y; Y10; Y10S; Y10S428/00; Y10S428/904; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/249979
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
121 words
A process for producing a porous sheet material which comprises (a) uniformly dispersing from about 10 to about 50 parts by weight of an inorganic salt in 100 parts by weight of a film-forming polyester type polyurethane, (b) applying the coating solution on a fibrous substrate or a film-making plate, (c) coagulating the coating layer with an aqueous coagulation medium comprising an aqueous solution of said inorganic salt, the concentration of said inorganic salt in said coagulating medium being below about two-thirds its concentration at saturation, and at least sufficient to yield a porous sheet upon coagulation of said polyurethane, said inorganic salt being selected from the group consisting of sodium sulfate, sodium chloride, potassium sulfate, potassium chloride and mixtures thereof.
Claim 2
Dependent Claim
121 words
A process for producing a porous sheet material which comprises (a) uniformly dispersing from about 10 to about 50 parts by weight of an inorganic salt in 100 parts by weight of a film-forming polyester type polyurethane, (b) applying the coating solution on a fibrous substrate or a film-making plate, (c) coagulating the coating layer with an aqueous coagulation medium comprising an aqueous solution of said inorganic salt, the concentration of said inorganic salt in said coagulating medium being below about two-thirds its concentration at saturation, and at least sufficient to yield a porous sheet upon coagulation of said polyurethane, said inorganic salt being selected from the group consisting of sodium sulfate, sodium chloride, potassium sulfate, potassium chloride and mixtures thereof.
Claim 3
Dependent Claim
26 words
The process as in claim 1, wherein the concentration of the inorganic salt in the coagulating medium is less than one-third of its concentration at saturation.
Claim 4
Dependent Claim
15 words
The process as in claim 1, wherein the temperature of the coagulating medium is 5*-50*C.
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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) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |