Patent US4118354A successfully refreshed from Google Patents.
US4118354A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyurethane hydrogel and method for the production of the same
Assignee: DKS Co Ltd
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Filing: 1976-08-17
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Granted: 1978-10-03
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Expires: 1996-08-17
Abstract
Abstract The improved polyurethane hydrogel is produced by dispersing a reaction product obtained by the reaction of a polyisocyanate having at least two isocyanate groups with a polyether. The polyether comprises a plurality of alkylene oxides, 50 to 90% by weight of which is ethylene oxide, added at random to a polyalcohol having at least two terminal hydroxyl groups in an amount of an average molecular weight within the range of 1,000 to 4,000 per said hydroxyl terminal group of said polyalcohol. The improved polyurethane hydrogel can have a greater water content and is highly stable and highly elastic.
Inventors
- 👤 Hideo Harada
- 👤 Nobuaki Matsushita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:06
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/48; C08G18/4833; C08G18/4837; C08G18/08; C08G18/10; C08G2210/00
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
111 words
A polyurethane hydrogel obtained by dispersing: (a) a reaction product obtained by the reaction of polyisocyanate having at least two isocyanate groups with a polyether into (b) an aqueous liquid phase; wherein the amounts of said (a) and (b) are such that the hydrogel product has a water content of 70 to 95% by weight and wherein said polyether is produced from a plurality of alkylene oxides, 75 to 85% by weight of which is ethylene oxide, added at random to a polyalcohol having at least two terminal hydroxyl groups in an amount to produce an average molecular weight of 2000 to 3000 per said terminal hydroxyl group of said polyalcohol.
Claim 2
Dependent Claim
111 words
A polyurethane hydrogel obtained by dispersing: (a) a reaction product obtained by the reaction of polyisocyanate having at least two isocyanate groups with a polyether into (b) an aqueous liquid phase; wherein the amounts of said (a) and (b) are such that the hydrogel product has a water content of 70 to 95% by weight and wherein said polyether is produced from a plurality of alkylene oxides, 75 to 85% by weight of which is ethylene oxide, added at random to a polyalcohol having at least two terminal hydroxyl groups in an amount to produce an average molecular weight of 2000 to 3000 per said terminal hydroxyl group of said polyalcohol.
Claim 3
Dependent Claim
12 words
The polyurethane hydrogel of claim 1, wherein said polyalcohol is ethylene glycol.
Claim 4
Dependent Claim
14 words
The polyurethane hydrogel of claim 1, wherein said polyalcohol has three terminal hydroxyl groups.
Claim 5
Dependent Claim
11 words
The polyurethane hydrogel of claim 3, wherein said polyalcohol is glycerine.
Claim 6
Dependent Claim
69 words
A polyurethane hydrogel as defined in claim 1, in which said polyether comprises ethylene oxide and propylene oxide added at random to glycerine in an amount of an average molecular weight within the range of 2,000 to 3,000 per terminal hydroxyl group of said glycerine, said ethylene oxide and propylene oxide being contained in said polyether at the ratio within the range of 75:25 to 85:15 by weight, respectively.
Claim 7
Dependent Claim
11 words
The polyurethane hydrogel of claim 1, wherein said polyalcohol is sorbitol.
Claim 8
Dependent Claim
23 words
The polyurethane hydrogel of claim 1, wherein the polyisocyanate is reacted with the polyether in an NCO/OH ratio of at least about 3.
Claim 9
Dependent Claim
22 words
A polyurethane hydrogel as defined in claim 1, in which said aqueous liquid phase is water or an aqueous solution or dispersion.
Claim 10
Dependent Claim
17 words
A polyurethane hydrogel as defined in claim 4, in which said aqueous liquid phase is sea water.
Claim 11
Dependent Claim
20 words
The polyurethane hydrogel of claim 4, wherein the aqueous phase is a solution of a carbonate, phosphate, oxalate or phthalate.
Claim 12
Independent Claim
120 words
A method for the production of a polyurethane hydrogel comprising dispersing: (a) a reaction product obtained by the reaction of polyisocyanate having at least two isocyanate groups with a polyether, into (b) an aqueous liquid phase to form a hydrogel; wherein the amounts of said (a) and (b) are such that the hydrogel product has a water content of 70 to 95% by weight and wherein said polyether is produced from a plurality of alkylene oxides, 75 to 85% by weight of which is ethylene oxide, added at random to a polyalcohol having at least two terminal hydroxyl group in an amount to produce an average molecular weight of 2000 to 3000 per said terminal hydroxyl group of said polyalcohol.
Claim 13
Independent Claim
120 words
A method for the production of a polyurethane hydrogel comprising dispersing: (a) a reaction product obtained by the reaction of polyisocyanate having at least two isocyanate groups with a polyether, into (b) an aqueous liquid phase to form a hydrogel; wherein the amounts of said (a) and (b) are such that the hydrogel product has a water content of 70 to 95% by weight and wherein said polyether is produced from a plurality of alkylene oxides, 75 to 85% by weight of which is ethylene oxide, added at random to a polyalcohol having at least two terminal hydroxyl group in an amount to produce an average molecular weight of 2000 to 3000 per said terminal hydroxyl group of said polyalcohol.
Claim 14
Dependent Claim
11 words
The method of claim 11, wherein said polyalcohol is ethylene glycol.
Claim 15
Dependent Claim
13 words
The method of claim 11, wherein said polyalcohol has three terminal hydroxyl groups.
Claim 16
Dependent Claim
10 words
The method of claim 13, wherein said polyalcohol is glycerine.
Claim 17
Dependent Claim
70 words
A method for the production of polyurethane hydrogel as defined in claim 11, in which polyether comprises ethylene oxide and propylene oxide added at random to glycerine in an average molecular weight within the range of 2,000 to 3,000 per terminal hydroxyl group of said glycerine, said ethylene oxide and propylene oxide being contained in said polyether at the ratio within the range of 75:25 to 85:15 by weight, respectively.
Claim 18
Dependent Claim
10 words
The method of claim 11, wherein said polyalcohol is sorbitol.
Claim 19
Dependent Claim
22 words
The method of claim 11, wherein the polyisocyanate is reacted with the polyether in an NCO/OH ratio of at least about 3.
Claim 20
Dependent Claim
28 words
A method for the production of a polyurethane hydrogel as defined in claim 11, in which said aqueous liquid phase is water or an aqueous solution or dispersion.
Claim 21
Dependent Claim
21 words
A method for the production of polyurethane hydrogel as defined in claim 14, in which aqueous liquid phase is sea water.
Claim 22
Dependent Claim
20 words
The method of claim 14, wherein the aqueous liquid phase is a solution of a carbonate, phosphate, oxalate or phthalate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-02 | 1982-04-03 | 1982-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-02 | 1986-04-03 | 1986-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-02 | 1990-04-03 | 1990-10-03 | $7700.00 | Window Closed / Lapsed |