Patent US3625871A successfully refreshed from Google Patents.
US3625871A
Expired / Lapsed
US
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Process for the production of microporous sheet structures and microporous sheet
Assignee: Bayer AG
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Filing: 1968-05-07
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Granted: 1971-12-07
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Expires: 1988-05-07
Abstract
Abstract Microporous sheet structures are prepared by reacting a polymeric polyamine having a molecular weight of from about 350 to about 6000 with substantially an equivalent amount of an organic polyisocyanate in the presence of a nonsolvent for the product, shaping the reaction mixture into a sheet structure before polyaddition is complete and removing the nonsolvent.
Inventors
- 👤 Harro Traubel
- 👤 Klaus Konig
- 👤 Wolfgang Heydkamp
- 👤 Karl Breer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:57
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; B; B01; B01J; B01J19/00; B01J19/18; B29; B29B; B29B7/00; B29B7/30; B29B7/34; B29B7/38; B29B7/40; B29B7/405; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/0838; C08G18/0842; C08G18/0861; C08G18/0871; C08G18/10; C08G18/12; D; D06; D06N; D06N3/00; D06N3/12; D06N3/14; B01J2219/00; B01J2219/00049; B01J2219/00051; B01J2219/00074; B01J2219/00087; B01J2219/00094; B01J2219/18; B01J2219/185; C08J2375/00; C08J2375/04; Y; Y10; Y10S; Y10S264/00; Y10S264/62; Y10S264/77; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/31
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
19 words
The process of claim 1 wherein the organic polyisocyanate is dissolved in an organic solvent therefor prior to mixing.
Claim 2
Dependent Claim
48 words
The process of claim 1 wherein the organic polyisocyanate is seleCted from the group consisting of monomeric organic polyisocyanates, NCO terminated prepolymers prepared by reacting an excess of a monomeric polyisocyanate with an organic compound having active hydrogen atoms that are reactive with NCO groups and mixtures thereof.
Claim 3
Dependent Claim
50 words
The process of claim 1 wherein the organic polyamine having a molecular weight of from about 350 to about 6,000 and at least two amino groups is mixed with lower molecular weight polyamines, the quantity of which does not exceed 50 mols percent based on the high molecular weight polyamines.
Claim 4
Dependent Claim
21 words
The process of claim 1 wherein both the organic polyisocyanate and the polyamine are dissolved or dispersed in organic solvents therefor.
Claim 5
Dependent Claim
45 words
The process of claim 1 wherein the organic polyamine having a molecular weight of from about 350 to about 6,000 and at least two amino groups is a reaction product of an excess of a low molecular polyamine or hydrazine with an isocyanato terminated prepolymer.
Claim 6
Dependent Claim
20 words
The process of claim 1 wherein the polyamine is dissolved or dispersed in an organic solvent therefor prior to mixing.
Claim 7
Dependent Claim
18 words
The process of claim 1 wherein (b) is dispersed in the nonsolvent before it is mixed with (a).
Claim 8
Dependent Claim
13 words
The process of claim 1 wherein water is dispersed into the organic polyamine.
Claim 9
Dependent Claim
11 words
A microporous sheet structure prepared by the process of claim 1.
Claim 10
Dependent Claim
16 words
The process of claim 1 wherein a nonsolvent for the polyamine is dispersed into the polyamine.
Claim 11
Dependent Claim
25 words
The process of claim 11 wherein the polyamine is dissolved in a solvent which is evaporated with the nonsolvent when the reaction is substantially complete.
Claim 12
Dependent Claim
22 words
The process of claim 12 wherein the vaporization number of the nonsolvent is at least 1 1/2 times that of the solvent.
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) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |