US4137360A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microporous sheets and a process for making them
Assignee: Bayer AG
•
Filing: 1974-08-28
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Granted: 1979-01-30
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Expires: 1994-08-28
Abstract
Abstract A method is provided for making microporous, vapor-permeable polyurethane sheets by coagulating a polyurethane in a polar solvent with a non-solvent for the polyurethane, wherein a polyurethane polysiloxane is added to the solution of the polyurethane in the polar solvent.
Inventors
- 👤 Artur Reischl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:21
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/0804; C08G18/0809; C08G18/0814; C08G18/0819; C08G18/0828; C08G18/10; C08G18/28; C08G18/30; C08G18/32; C08G18/3203; C08G18/3206; C08G18/38; C08G18/3855; C08G18/3857; C08G18/40; C08G18/42; C08G18/4202; C08G18/4205; C08G18/4208; C08G18/4211; C08G18/4216; C08G18/4236; C08G18/4238; C08G18/44; C08G18/65; C08G18/66; C08G18/6633; C08G18/6637; C08G18/664; C08G18/70; C08G18/72; C08G18/73; C08G18/74; C08G18/76; C08G18/7614; C08G18/7621; C08G18/7657; C08G18/7664; C08G18/7671; C08G77/00; C08G77/42; C08G77/452; C08G77/458; C08L; C08L75/00; D; D06; D06M; D06M15/00; D06M15/19; D06M15/37; D06M15/564; D06M15/643; D06M15/6436; D06M15/653; D06N; D06N3/00; D06N3/12; D06N3/14; C08G77/04; C08G77/14; C08G77/16; C08J2375/00; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
152 words
In a process for making microporous sheets which are permeable to water vapor comprising applying a polyurethane in a hygroscopic polar solvent to a substrate, coagulating the polyurethane with a non-solvent for the polyurethane, removing the solvent and non-solvent, and optionally, removing the substrate, the improvement which comprises coagulating a solution containing a polyurethane which has the following structural unit ##STR8## in which n ≧ 2 Z = an alkyl group containing 1 to 5 carbon atoms, an aryl radical containing 6 to 15 carbon atoms, a siloxyl or siloxanyl group or ##STR9## the groups Z being the same or different; R = an alkylene group and Y = --nh--, --o--, --s-- or NR 1 where R 1 is an alkyl group containing 1 to 5 carbon atoms or a cyclohexyl radical and the total quantity of siloxane sequences in the microporous polyurethane sheet is about 0.1 to about 20% by weight.
Claim 2
Dependent Claim
152 words
In a process for making microporous sheets which are permeable to water vapor comprising applying a polyurethane in a hygroscopic polar solvent to a substrate, coagulating the polyurethane with a non-solvent for the polyurethane, removing the solvent and non-solvent, and optionally, removing the substrate, the improvement which comprises coagulating a solution containing a polyurethane which has the following structural unit ##STR8## in which n ≧ 2 Z = an alkyl group containing 1 to 5 carbon atoms, an aryl radical containing 6 to 15 carbon atoms, a siloxyl or siloxanyl group or ##STR9## the groups Z being the same or different; R = an alkylene group and Y = --nh--, --o--, --s-- or NR 1 where R 1 is an alkyl group containing 1 to 5 carbon atoms or a cyclohexyl radical and the total quantity of siloxane sequences in the microporous polyurethane sheet is about 0.1 to about 20% by weight.
Claim 3
Dependent Claim
45 words
The process of claim 1 wherein a high molecular weight polyurethane polysiloxane having a siloxane content of about 5 to about 60 percent by weight, and a molecular weight of about 5000 to 30,000 is prepared and added to a hygroscopic polyurethane solution before coagulation.
Claim 4
Dependent Claim
21 words
The process of claim 1 wherein the polysiloxane-polyurethane contains ionic groups and is used while diluted with a solvent or water.
Claim 5
Dependent Claim
39 words
The process of claim 1 wherein a non-ionic polysiloxane polyurethane is emulsified in an aqueous polyurethane dispersion or suspension, and added in this form to a polyurethane elastomer solution which is to be coagulated, before coagulation is carried out.
Claim 6
Dependent Claim
29 words
The process of claim 1 wherein n = 5 to 100, Z = methyl, and the siloxane units in the sheet are about 0.3 to about 5% by weight.
Claim 7
Dependent Claim
8 words
The product of the process of claim 1.
Claim 8
Dependent Claim
16 words
The process of claim 1 wherein the said polyurethane is the solution of a polyurethane urea.
Claim 9
Dependent Claim
19 words
The process of claim 1 wherein the polyurethane in the solution prior to coagulation is free from urea linkages.
Claim 10
Dependent Claim
22 words
A process according to claim 1 wherein only one of the Z substituents attached to a silicon atom is the group ##STR10##
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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) | 1982-01-29 | 1982-07-31 | 1983-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-29 | 1986-07-31 | 1987-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-29 | 1990-07-31 | 1991-01-30 | $7700.00 | Window Closed / Lapsed |