US4644033A
Expired / Lapsed
US
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Polyurethane hydrogels and process for their manufacture
Assignee: EssilorLuxottica SA
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Filing: 1985-05-23
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Granted: 1987-02-17
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Expires: 2005-05-23
Abstract
Abstract The hydrogels consist essentially of the polyurethane of polyoxyethylene. The crosslinking is carried out by a reaction of a polyfunctional isocyanate with the polyoxyethylene in solution in a non-aqueous solvent. Transparent hydrogels are obtained, having a high swelling ratio in the presence of water and good mechanical properties.
Inventors
- 👤 Yves Gnanou
- 👤 Gerard Hild
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:19
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/72; C08G18/77; C08G18/78; C08G18/7806; C08G18/7818; C08G18/7831; C08G18/28; C08G18/40; C08G18/48; C08G18/4833; C08G18/65; C08G18/66; C08G18/6666; C08G18/667; C08G18/6674; C08G18/6677; C08G18/80; C08G18/8003; C08G18/8006; C08G18/8009; C08G18/8022; C08G18/8029; C08G2210/00; Y; Y10; Y10S; Y10S525/00; Y10S525/937
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
54 words
A molded article of a polyurethane hydrogel comprising a polyoxyethylene polyurethane one step crosslinking reaction product of a polyfunctional isocyanate with a polyoxyethylene in solution in a non-aqueous solvent which is substantially non-reactive for said polyisocyanate essentially in absence of water in an inert atmosphere to yield a gel swollen by the non-aqueous solvent.
Claim 2
Dependent Claim
54 words
A molded article of a polyurethane hydrogel comprising a polyoxyethylene polyurethane one step crosslinking reaction product of a polyfunctional isocyanate with a polyoxyethylene in solution in a non-aqueous solvent which is substantially non-reactive for said polyisocyanate essentially in absence of water in an inert atmosphere to yield a gel swollen by the non-aqueous solvent.
Claim 3
Dependent Claim
22 words
The molded article of claim 1, wherein the polyoxyethylene contains two alcohol groups per molecule, the polyfunctional isocyanate then being a triisocyanate.
Claim 4
Dependent Claim
30 words
The molded article of claim 1, as produced from a composition comprising a polyoxyethylene containing two alcohol groups per molecule, a diisocyanate and a cross-linking agent consisting of a triol.
Claim 5
Dependent Claim
42 words
The molded article of claim 1 wherein the hydrogel has a water content of from 30 to 99% by volume at its swelling equilibrium in water, and an elasticity modulus of the order of 10 5 to 3.10 6 dynes/cm 2 .
Claim 6
Dependent Claim
16 words
The molded article of claim 4, wherein said content is from 60 to 95% by weight.
Claim 7
Dependent Claim
18 words
The molded article of claim 4, having an extractible content not more than 3% by weight in water.
Claim 8
Dependent Claim
46 words
A molded article of a transparent polyurethane hydrogel, containing from 70 to 97% by weight of water at its swelling equilibrium in water, and not more than 5% by weight extractible content and having an elasticity modulus of 10 5 to 3.10 6 dynes/cm 2 .
Claim 9
Dependent Claim
46 words
A molded article of a transparent polyurethane hydrogel, containing from 70 to 97% by weight of water at its swelling equilibrium in water, and not more than 5% by weight extractible content and having an elasticity modulus of 10 5 to 3.10 6 dynes/cm 2 .
Claim 10
Dependent Claim
52 words
A process for manufacturing a molded article of claim 1 comprising reacting, in one step, a polyfunctional isocyanate with a polyoxyethylene in solution in a non-aqueous solvent which is substantially unreactive towards the polyisocyanate, essentially in absence of water in an inert atmosphere to yield a gel swollen by the non-aqueous solvent.
Claim 11
Dependent Claim
75 words
A process for manufacturing a molded article according to claim 1, comprising reacting in one step a polyfunctional isocyanate with a polyoxyethylene in solution in a non-aqueous solvent which is substantially unreactive towards the polyisocyanate essentially in absence of water in an inert atmosphere to yield a gel swollen by the non-aqueous solvent said gel being then contacted with water, thereby achieving the swelling of the gel with water as a replacement for the solvent.
Claim 12
Dependent Claim
19 words
A process according to claim 8, wherein the polyoxyethylene has a number average molecular weight between 500 and 20,000.
Claim 13
Dependent Claim
17 words
A process according to claim 10, wherein said number average molecular weight is between 1,000 and 10,000.
Claim 14
Dependent Claim
25 words
A process according to claim 8, wherein the concentration of polyoxyethylene in the mixture dissolved in the solvent is between 5 and 80% by weight.
Claim 15
Dependent Claim
20 words
A process according to claim 8, wherein the solvent is chosen from dimethyl-formamide N-methylpyrrolidone, tetrahydrofuran, dioxan, ethyl acetate and dichloroethane.
Claim 16
Dependent Claim
84 words
A process for manufacturing a hydrogel molded article according to claim 1, comprising reacting, in one step, a polyfunctional isocyanate with a polyoxyethylene in solution in a non-aqueous solvent which is substantially unreactive towards the polyisocyanate, essentially in absence of water in an inert atmosphere, wherein the mixture is introduced into a mold to react with a quantity of solvent corresponding substantially to that which the gel formed contains in the swollen state at equilibrium, thereby yielding a gel swollen by the non-aqueous solvent.
Claim 17
Dependent Claim
21 words
Articles consisting of a polyurethane hydrogel having the characteristics of claim 1 or manufactured by the process according to claim 8.
Claim 18
Dependent Claim
12 words
Articles according to claim 15, produced in the form of contact lenses.
Claim 19
Dependent Claim
34 words
An article according to claim 15 comprising a polyurethane hydrogel containing from 70 to 97% by weight of water at its swelling equilibrium in water, and not more than 5% by weight extractable content.
Claim 20
Dependent Claim
20 words
The article of claim 17 wherein the polyurethane hydrogel is a molded hydrogel and the article is a contact lense.
Claim 21
Dependent Claim
13 words
The process of claim 8 wherein the reaction takes place in a mold.
Claim 22
Dependent Claim
80 words
A process for manufacturing a hydrogel according to claim 1 comprising reacting in a mold, in one step, a polyfunctional isocyanate with a polyoxyethylene in solution in a non-aqueous solvent which is substantially unreactive towards the polyisocyanate essentially in absence of water in an inert atmosphere, wherein the amount of solvent is substantially just that required to swell the gel formed further comprising evaporating the non-aqueous solvent and thereafter contacting the gel with water as a replacement for the solvent.
Claim 23
Dependent Claim
19 words
The molded article of claim 1, wherein the polyoxyethylene has a number average molecular weight of 500 to 20,000.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-16 | 1990-08-18 | 1991-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-16 | 1994-08-18 | 1995-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-16 | 1998-08-18 | 1999-02-17 | $7700.00 | Window Closed / Lapsed |