US3720631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sheet materials of excellent durability and method of manufacturing the same
Assignee: Kuraray Co Ltd
•
Filing: 1970-09-28
•
Granted: 1973-03-13
•
Expires: 1990-09-28
Abstract
Abstract A highly durable sheet material using for synthetic leather is prepared by dipping a layer of a solution of a polyurethane elastomer which is derived from both a polyester having a molecular weight of 800 to 3000 and a polyether having a molecular weight of 800 to 3000 as soft segments, the molar ratio of the polyester to the polyether being from 10:90 to 65:35, and in which elastomer the weight of nitrogen atoms contained in the urethane groups ranges from 3.8 to 6 percent of the total weight of the polyurethane elastomer, into a coagulation bath composed of a solvent and a non-solvent for the polyurethane elastomer at a ratio by weight ranging from 20:80 to 70:30, thereby coagulating said layer of the elastomer into a microporous structure.
Inventors
- 👤 T Iwamoto
- 👤 O Fukushima
- 👤 K Nagoshi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:01
CPC Classifications
D; D06; D06N; D06N3/00; D06N3/12; D06N3/14; C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/4009; C08G18/4018
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
171 words
A sheet material comprising a microporous layer of a polyurethane elastomer derived from a polyester glycol having a molecular weight of from 800 to 3000 selected from the group consisting of polycaprolactone and a polycondensation product of an aliphatic dicarboxylic acid and a glycol selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, hexamethylene glycol or mixtures thereof and a polyether glycol having a molecular weight of from 800 to 3000 selected from the group consisting of polyethylene ether glycol, polypropylene ether glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, polyethylene propylene ether glycol and a block copolyether of ethylene oxide and tetramethylene oxide, an organic diisocyanate, and a glycol chain extender having two active hydrogen atoms selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol and hexamethylene glycol, the molar ratio of the polyester glycol to the polyether glycol being 10:90 to 65:35; the weight of nitrogen atoms in the urethane groups being from 3.8 to 6 percent of the total weight of the elastomer.
Claim 2
Dependent Claim
171 words
A sheet material comprising a microporous layer of a polyurethane elastomer derived from a polyester glycol having a molecular weight of from 800 to 3000 selected from the group consisting of polycaprolactone and a polycondensation product of an aliphatic dicarboxylic acid and a glycol selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, hexamethylene glycol or mixtures thereof and a polyether glycol having a molecular weight of from 800 to 3000 selected from the group consisting of polyethylene ether glycol, polypropylene ether glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, polyethylene propylene ether glycol and a block copolyether of ethylene oxide and tetramethylene oxide, an organic diisocyanate, and a glycol chain extender having two active hydrogen atoms selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol and hexamethylene glycol, the molar ratio of the polyester glycol to the polyether glycol being 10:90 to 65:35; the weight of nitrogen atoms in the urethane groups being from 3.8 to 6 percent of the total weight of the elastomer.
Claim 3
Dependent Claim
32 words
A sheet material as claimed in claim 1 in which the weight of nitrogen atoms in the urethane groups is from 3.8 to 4.2 percent of the total weight of the elastomer.
Claim 4
Dependent Claim
20 words
A sheet material as claimed in claim 1 in which the aliphatic dicarboxylic acid is adipic acid or sebacic acid.
Claim 5
Dependent Claim
17 words
A sheet material as claimed in claim 1 in which the organic diisocyanate is an aromatic diisocyanate.
Claim 6
Dependent Claim
27 words
A sheet material as claimed in claim 4 in which the aromatic diisocyanate is a naphthalene diisocyanate, a diphenylmethane diisocyanate, a diphenyl diisocyanate or a tolylene diisocyanate.
Claim 7
Dependent Claim
17 words
A sheet material as claimed in claim 1 in which the organic diisocyanate is an aliphatic diisocyanate.
References Cited (Backward Citations)
US3000757A
Cited
US3100721A
Cited
US3208875A
Cited
US3236812A
Cited
US3369925A
Cited
US3348963A
Cited
US3590112A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |