Hydrophilic polyurethane composition

• US 4,798,876 A
• Filed: 11/12/1985
• Issued: 01/17/1989
• Est. Priority Date: 11/12/1985
• Status: Expired due to Fees

• Current Assignee: Tyndale Plains-Hunter, Ltd.
• Original Assignee: Tyndale Plains-Hunter, Ltd.
• Inventors: Morgan, Ellen K., Reduker, Stephen D., Gould, Francis E.
• Primary Examiner(s): Terapane, John F.
• Assistant Examiner(s): Maples, John S.
• Application Number:
  US06/797,407
• Time in Patent Office: 1,162 Days
• Field of Search: 525/457, 525/454, 525/458, 424/DIG. 13, 128/132 D, 128/132 R, 128/138 A, 128/138 R, 521/905
• US Class Current: 525/457
• CPC Class Codes: A61L 27/26 Mixtures of macromolecular compounds
• CPC Class Codes: C08G 18/6674 with compounds of group C08G18/3203
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: C08L 75/06 from polyesters
• CPC Class Codes: C08L 75/08 from polyethers
• CPC Class Codes: G02B 1/043 Contact lenses

Abstract

Water absorptive polyurethane composition, having high mechanical strength, is formed of A. about 25% to about 75% of a hydrophilic polyether polyurethane which is the reaction product of diethylene glycol and a polyoxyethylene glycol having a molecular weight of about 1000 to about 8000 with a polyisocyanate and B. about 75% to about 25% of a hydrophobic polyester polyurethane which is the reaction product of a polyfunctional polyester derived from the condensation of a polyol with a polybasic acid with a polyisocyanate.

Claims

1. A water absorptive polyurethane composition comprising by weight a physical blend of A. about 25% to about 75% of a hydrophilic polyether polyurethane which is the reaction product of diethylene glycol and a polyoxyethylene glycol having a molecular weight of about 1000 to about 8000 with a polyisocyanate and B. about 75% to about 25% of a hydrophobic polyester polyurethane which is the reaction product of a polyfunctional polyester, derived from the condensation of a polyol with a polybasic acid, with a polyisocyanate.

2. The composition of claim 1 wherein the molecular weight of the polyethylene glycol is about 1450.

3. The composition of claim 1 wherein the molecular weight of the polyethylene glycol is about 7500 to 8000.

4. The composition of claim 1 containing 40% of A. and 60% of B.

5. The composition of claim 1 containing 60% of A. and 40% of B.

6. The composition of claim 1 wherein the polyester polyurethane is the condensation product of a polyisocyanate and a polyester polyol derived from a polycarboxylic acid and an aliphatic diol.

7. The composition of claim 6 wherein the polyester polyol is derived from a dicarboxylic acid having 6 to 10 carbon atoms and an alkylene diol of 3 to 4 carbon atoms and the polyisocyanate is toluene diisocyanate.