Claims
- 1. A water-dispersible polyurethane comprising a polyurethane containing carboxylate groups covalently bonded to gelatin said water-dispersable polyurethane formed by:
- providing a polyurethane dispersion containing carboxylate groups wherein the polyurethane dispersion has an acid number of at least 5;
- contacting the polyurethane dispersion with a grafting agent selected from the group consisting of carbamoylonium salts, dication ethers and carbodiimides;
- contacting the polyurethane dispersion, contacted with the grafting agent, with gelatin to form a polyurethane covalently bonded to gelatin wherein a weight ratio of gelatin to polyurethane is from 1:10 to 2:1.
- 2. A process for making a water-dispersible polyurethane comprising:
- providing a polyurethane dispersion containing carboxylate groups wherein the polyurethane dispersion has an acid number of at least 5;
- contacting the polyurethane dispersion with a grafting agent selected from the group consisting of carbamoylonium salts, dication ethers and carbodiimides;
- contacting the polyurethane dispersion, contacted with the grafting agent, with gelatin to form a polyurethane covalently bonded to gelatin wherein a weight ratio of gelatin to polyurethane is from 1:10 to 2:1.
- 3. The process of claim 2 wherein the contacting of the polyurethane with gelatin is in an aqueous medium.
- 4. The process of claim 3 wherein the polyurethane has a concentration of less than 25 weight percent in the aqueous medium.
- 5. The process of claim 2 further comprising:
- washing the polyurethane covalently bonded to gelatin.
- 6. A water-dispersible polyurethane comprising a polyurethane containing carboxylate groups covalently bonded to gelatin through a grafting agent selected from the group consisting of carbamoylonium salts, dication ethers and carbodiimides, wherein the polyurethane containing carboxylate groups has an acid number of at least 5 and wherein the weight ratio of gelatin to polyurethane is from 1:10 to 2:1.
CROSS REFERENCE TO RELATED APPLICATIONS
This application relates to commonly assigned copending application Ser. No. 09/090,831, filed simultaneously herewith. This application relates to commonly assigned copending application Ser. No. 09/090,579, filed simultaneously herewith. This application relates to commonly assigned copending application Ser. No. 09/090,576, filed simultaneously herewith. This application relates to commonly assigned copending application Ser. No. 09/090,827, filed simultaneously herewith.
US Referenced Citations (9)
Foreign Referenced Citations (1)
Number |
Date |
Country |
476 535 B1 |
Mar 1992 |
EPX |
Non-Patent Literature Citations (1)
Entry |
Research Disclosure No. 38957, Sep. 1996, p. 601. |