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US 5,844,013 AGranted
Hydrophilic polyurethane gel foams, particularly for treating deep wounds, wound dressing based on hydrophilic polyurethane gel foams and method of manufacture
AssigneeBeiersdorf AG
InventorsJochen Kenndoff, Vadim Lenuck, Gunther Sachau
Life of this patent
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Abstract
Hydrophilic polyurethane gel foams are obtainable from a polyurethane gel defined in the description, from a water-absorbing material and from a non-aqueous foaming agent and can be used in medicine, in particular for the management of deep wounds and wound cavities. Wound dressings are obtainable with a polyurethane sheet as backing and a polyurethane gel foam composed of a polyurethane gel defined in the description, of a water-absorbing material and of a non-aqueous foaming agent.
Claims46
Self-adhesive, hydrophilic polyurethane gel foams formed by mixing
- 1. a polyurethane gel which comprises
- (A) 15-62% by weight, based on the total of (A) and (B) of a covalently crosslinked polyurethane as a matrix and
- (B) 85-38% by weight, based on the total of (A) and (B), of one or more polyhydroxyl compounds which are bound in the matrix by secondary valence forces and have an average molecular weight between 1000 and 12000, and an average OH number between 20 and 112, as liquid dispersant, the dispersant being free of hydroxyl compounds with a molecular weight below 800, and, where appropriate,
- (C) 0-100% by weight, based on the total of (A) and (B), of fillers and/or additives,
- and which is prepared by reacting a mixture of
- a) one or more polyisocyanates
- b) one or more polyhydroxyl compounds with an average molecular weight between 1000 and 12000, and with an average OH number between 20 and 112,
- c) optionally, catalysts or accelerators for the reaction between isocyanate groups and hydroxyl groups and, optionally,
- d) fillers and additives,
- this mixture being free of hydroxyl compounds with a molecular weight below 800, the average functionality of the polyisocyanates (F.sub.I) being between 2 and 4, the average functionality of the polyhydroxyl compound (F.sub.P) being between 3 and 6, and the isocyanate index (K) being given by the formula ##EQU4## in which X.ltoreq.120, and the index K has values between 15 and 70,
7 more elements
Hydrophilic polyurethane gel foams formed by mixing
- 1. a polyurethane gel which comprises
- (A) 35-62% by weight, based on the total of (A) and (B) of a covalently crosslinked polyurethane as a matrix and
- (B) 65-38% by weight, based on the total of (A) and (B), of one or more polyhydroxyl compounds which are bound in the matrix by secondary valence forces and have an average molecular weight between 1000 and 12000, and an average OH number between 20 and 112, as liquid dispersant, the dispersant being free of hydroxyl compounds with a molecular weight below 800, and, optionally,
- (C) 0-100% by weight, based on the total of (A) and (B), of fillers and/or additives,
- and which is prepared by reacting a mixture of
- a) one or more polyisocyanates
- b) one or more polyhydroxyl compounds with an average molecular weight between 1000 and 12000, and with an average OH number between 20 and 112,
- c) where appropriate catalysts or accelerators for the reaction between isocyanate groups and hydroxyl groups and, optionally,
- d) fillers and additives,
- this mixture being free of hydroxyl compounds with a molecular weight below 800, the average functionality of the polyisocyanates (F.sub.I) being between 2 and 4, the average functionality of the polyhydroxyl compound (F.sub.P) being between 3 and 6, and the isocyanate index (K) being given by the formula ##EQU5## in which X.ltoreq.120, and the index K has values between 15 and 70, where the stated averages of molecular weight and OH number are to be understood as number averages,
- 2. a water-absorbing material and
- 3. a non-aqueous foaming agent, foaming the mixture and curing.
9 more elements
Wound dressings comprising a polyurethane sheet as backing and hydrophilic polyurethane gel foams applied thereto, which are formed by mixing
- 1. a polyurethane gel which comprises
- (A) 25-62% by weight, based on the total of (A) and (B) of a covalently crosslinked polyurethane as a matrix and
- (B) 75-38% by weight, based on the total of (A) and (B), of one or more polyhydroxyl compounds which are bound in the matrix by secondary valence forces and have an average molecular weight between 1000 and 12000, and an average OH number between 20 and 112, as liquid dispersant, the dispersant being free of hydroxyl compounds with a molecular weight below 800, and, optionally,
- (C) 0-100% by weight, based on the total of (A) and (B), of fillers and/or additives,
- and which is prepared by reacting a mixture of
- a) one or more polyisocyanates
- b) one or more polyhydroxyl compounds with an average molecular weight between 1000 and 12000, and with an average OH number between 20 and 112,
- c) where appropriate catalysts or accelerators for the reaction between isocyanate groups and hydroxyl groups and, optionally,
- d) fillers and additives,
- this mixture being free of hydroxyl compounds with a molecular weight below 800, the average functionality of the polyisocyanates (F.sub.I) being between 2 and 4, the average functionality of the polyhydroxyl compound (F.sub.P) being between 3 and 6, and the isocyanate index (K) being given by the formula ##EQU6## in which X.ltoreq.120, and the index K has values between 15 and 70, where the stated averages of molecular weight and OH number are to be understood as number averages,
- 2. a water-absorbing material and
- 3. a non-aqueous foaming agent, foaming the mixture and curing.
9 more elements
Dependencies are inferred from the claim text.