US3715326A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Using monoisocyanates to prepare microporous polyurethanes
Assignee: Bayer AG
•
Filing: 1970-12-04
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Granted: 1973-02-06
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Expires: 1990-12-04
Abstract
Abstract Microporous foils and films are prepared from solutions of a polyurethane or polyurethane urea polymer in a strong polar solvent, the polymer having film forming properties and a molecular weight of at least 10,000 by mixing with the solution from 2 to 200 percent by weight based on the weight of the polymer of (1) and alkyl isocyanate or (2) a polar aliphatic compound having a melting point greater than 35* C. and at least one alkyl or alkylene substituent containing two to 24 carbon atoms, the aliphatic compound being a carboxylic acid amide, a urethane, a urea or a semicarbazide, shaping the solvent solution into a foil or film, removing the solvent and drying the film or foil at a temperature below the softening point of the polyurethane or polyurethane urea polymer.
Inventors
- 👤 H Traubel
- 👤 H Oertel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:25
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/71; C08J2375/00; C08J2375/04; Y; Y10; Y10S; Y10S521/00; Y10S521/918
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
122 words
A method of preparing microporous polyurethane films and foils which comprises preparing a solution of a polyurethane polymer or a polyurethane urea polymer in a strong polar solvent which will dissolve polyacrylonitrile said polymer containing substantially no free terminal OH or NH2 groups and having film forming properties and a molecular weight of at least 10,000, introducing into said solution from about 2 to about 200 percent by weight of said polymer of R''''-NCO wherein R'''' is an alkyl radical having eight to 24 carbon atoms, shaping said solvent solution into a film or foil on a substrate, washing out the solvent and drying the film or foil at a temperature below the softening point of the polyurethane or polyurethane urea polymer.
Claim 2
Independent Claim
122 words
A method of preparing microporous polyurethane films and foils which comprises preparing a solution of a polyurethane polymer or a polyurethane urea polymer in a strong polar solvent which will dissolve polyacrylonitrile said polymer containing substantially no free terminal OH or NH2 groups and having film forming properties and a molecular weight of at least 10,000, introducing into said solution from about 2 to about 200 percent by weight of said polymer of R''''-NCO wherein R'''' is an alkyl radical having eight to 24 carbon atoms, shaping said solvent solution into a film or foil on a substrate, washing out the solvent and drying the film or foil at a temperature below the softening point of the polyurethane or polyurethane urea polymer.
Claim 3
Dependent Claim
70 words
A method according to claim 1 wherein the polyurethane or polyurethane urea polymer is prepared by reacting an organic compound containing active hydrogen atoms that are active with NCO groups, said compound having a molecular weight of from about 500 to 5,000 and a chain extending agent containing active hydrogen atoms that are reactive with NCO groups and having a molecular weight less than about 250 with an organic diisocyanate.
Claim 4
Dependent Claim
66 words
A method according to claim 2 wherein the polyurethane or polyurethane urea polymer is prepared by first preparing an NCO terminated prepolymer having an NCO content of at least 0.5 percent by weight in a first step by reacting an excess of the organic diisocyanate with the organic compound having a molecular weight of 500 to 5,000 and reacting said prepolymer with the chain extending agent.
Claim 5
Dependent Claim
124 words
A process according to claim 1 wherein a filament having the following physical properties: Melting point of Kofler bench at least 150* C. Tensile strength at least about 100 kg/cm2. Elongation at break at least 200 percent. Tensile resilience at first elongation to 20 percent at least 1 kg/cm2 and at 100% elongation at least 5 kg/cm2. A molecular weight corresponds to the viscosity when 1.0 g of polymer at 20* C is dissolved in 100 ml of hexamethyl phosphoramide at 20* C. where R is relative viscosity and C is concentration in g/100 ml. is prepared by applying a solution of the polyurethane or polyurethane urea polymer to a glass plate and drying at 100* C and cutting the resulting film into filaments.
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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) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |