Claims
- 1. A method for making an impregnated textile synthetic leather, the method comprising:
(a) impregnating a non-woven or woven textile with a polyurethane dispersion comprised of a nonionizable polyurethane and an external stabilizing surfactant; and (b) exposing the impregnated textile to water containing a coagulant for a coagulation time sufficient to coagulate the dispersion.
- 2. The method of claim 1, wherein the method is carried out in an environment containing less than about 2000 parts per million by weight of an organic solvent.
- 3. The method of claim 1, wherein the method is carried out essentially free of an organic solvent.
- 4. The method of claim 1, wherein the coagulant is a multivalent cation neutral salt.
- 5. The method of claim 4, wherein the coagulant is an alkaline earth cation salt.
- 6. The method of claim 5, wherein the coagulant is calcium nitrate, magnesium nitrate, strontium nitrate and barium nitrate or mixture thereof.
- 7. The method of claim 3, wherein the polyurethane dispersion contains non-polyurethane polymeric particles.
- 8. The method of claim 1, wherein the coagulant time is at most 2 minutes.
- 9. The method of claim 8, wherein the coagulant time is at most 1 minute.
- 10. The method of claim 9, wherein the coagulant time is at most 30 seconds.
- 11. The method of claim 1, further comprising leaching the impregnated textile after step (b) by exposing the impregnated textile to water.
- 12. The method of claim 1, wherein the polyurethane dispersion contains a thickener.
- 13. The method of claim 12 wherein the thickener is water soluble thickener that is not ionizable.
- 14. The method of claim 13 wherein the thickener is a methylcellulose ether.
- 15. The method of claim 1 further comprising applying a frothed polymeric dispersion after step (b) to form a synthetic leather having a poromeric layer thereon.
- 16. The method of claim 15 wherein the frothed polymeric dispersion is an aqueous externally stabilized polyurethane dispersion.
- 17. The method of claim 16 wherein the poromeric layer is heated sufficiently to dry and cure the poromeric layer and then is leached in water.
- 18. A method for making synthetic leather having a poromeric layer thereon, the method comprising:
(a) applying onto a textile, impregnated with a polymer, a frothed aqueous polyurethane dispersion, the aqueous polyurethane dispersion having an externally stabilizing surfactant; and then (b) heating to a temperature sufficient to dry and cure the product of step (a) to form the synthetic leather having a poromeric layer.
- 19. The method of claim 18, wherein the frothed aqueous polyurethane is of an aromatic polyisocyanate.
- 20. The method of claim 19, wherein the aromatic polyisocyanate is 2,2′-diphenyl-methanediisocyanate, 4,4,diphenyl-methanediisocyanate, 2,4′ diphenyl-methanediisocyanate or mixture thereof.
- 21. The method of claim 18, wherein the frothed polyurethane dispersion is frothed mechanically.
- 22. The method of claim 18 wherein the synthetic leather of step (b) is leached using water essentially free of organic solvents for a time sufficient to remove at least about 10% by weight of the externally stabilizing surfactant.
- 23. The method of claim 22, wherein the synthetic leather of step (b) is leached for a time sufficient to remove at least 50% of the externally stabilizing surfactant.
- 24. The method of claim 23 wherein the synthetic leather of step (b) is leached for time sufficient to remove at least 70% of the externally stabilizing surfactant.
- 25. The method of claim 18 wherein the externally stabilized surfactant is a mixture of an anionic and an amphoteric surfactant.
- 26. The method of claim 25, wherein the amphoteric surfactant is a betaine.
- 27. The method of claim 18 wherein the method is performed essentially free of organic solvents.
- 28. A synthetic leather comprised of a textile having a plurality of fibers wherein the textile has therein a polyurethane and a multivalent cation substantially water insoluble salt of an organic acid.
- 29. The synthetic leather of claim 28 wherein the organic acid is butyric acid; hexanoic acid; octanoic acid; decanoic acid; dodecanoic acid; lauric acid; myristic acid; palmitic acid; oleic acid; linoleic acid; stearic acid; linolenic acid; dodecylbenzene sulfonic acid; or mixture thereof.
- 30. The synthetic leather of claim 28 wherein the multivalent cation of the water insoluble salt is an alkaline earth.
- 31. The synthetic leather of claim 30 wherein the multivalent cation is calcium.
- 32. The synthetic leather of claim 28, wherein the textile has a permeable polymeric poromeric layer thereon.
- 33. The synthetic leather of claim 32, wherein the poromeric layer is polyurethane.
- 34. The synthetic leather of claim 33 wherein the polyurethane of the poromeric layer is of an aqueous externally stabilized polyurethane essentially free of any organic solvent.
- 35. The synthetic leather of claim 32, wherein the porous cellular coating has uniformly spherical pores having an average size between about 300 micrometers squared to 25000 micrometers squared by number.
- 36. A synthetic leather comprised of a textile having a poromeric layer comprised of polyurethane thereon wherein the synthetic leather has an amount of a surfactant of at least a trace amount to at most about 4% by weight of the poromeric layer and a wet ply adhesion of at least about 1.5 kg/cm.
- 37. The synthetic layer of claim 36, wherein the amount of surfactant is at most about 2% by weight of the poromeric layer.
- 38. The synthetic leather of claim 36, wherein the poromeric layer has uniformly spherical pores having an average size between about 300 micrometers squared to 25000 micrometers squared by number.
- 39. The synthetic leather of claim 36, wherein the synthetic leather has a wet ply adhesion of at least about 2.0 kg/cm.
- 40. The synthetic leather of claim 38 wherein the poromeric layer polyurethane is of an externally stabilized polyurethane dispersion.
- 41. The synthetic leather of claim 36 wherein the synthetic leather was prepared in an environment essentially free of an organic solvent.
- 42. The synthetic leather of claim 36 wherein the textile was impregnated with a polymer.
- 43. The synthetic leather of claim 42 wherein the polymer was polyurethane.
Parent Case Info
[0001] This application claims the benefit of U.S. Provisional Application No. 60/435,823 filed on Dec. 20, 2002.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60435823 |
Dec 2002 |
US |