Claims
- 1. A method for forming an adhesive layer on a substrate which comprises:applying to the substrate a nonlonic, water-soluble polyurethane consisting essentially of the groups: (a) —O—(OH2—OH2 O—)n, wherein n is a number of 8-500; (b) —CO—NH—X—NH—CO— wherein X is an aliphatic or cycloeliphatic group; and (c) —O—Y—O—, wherein Y comprises a hydrophobic moiety selected from the group consisting of (—CH2—CH(CH3)—O)m—CH2—CH(CH3)—, (CH2 CH(C2H5)—O)m—CH2—CH(C2H5)—, (CH2—CH2—CH2—CH2 O)m—CH2 CH2 CH2 CH2—, alkylene groups having from 2 to 44 carbon atoms, cyoloalkylene groups having from 6 to 44 carbon atoms and mixtures thereof wherein m is a number of 8 to 500, the nonionic polyurethane forms a homogenous mixture with water; the mixture having a specific viscosity of at least 0.4 at a 1% by weight solution in water at 20° C. wherein (c) comprises from 2% to 40% by weight, based on (a)+(c) of the polyurethane and wherein at least one of the following conditions is met: (i) the nonionic polyurethane is soluble in water at any mixing ratio at 20° C.; (ii) n is 20 to 300 and m is 20 to 300 (iii) (c) comprises residues of a diol having a solubility in water not greater than 2 grams/100 grams of water; (iv) the equivalent ratio of (a) to (c) is greater than 1:1; (v) (c) comprises a hydrophobic polyoxyalkylene moiety wherein the alkylene group contains 3 or 4 atoms.
- 2. The method as claimed in claim 1 wherein the nonionic polyurethane has a degree of crystallization of 20% to 80%, based on the degree of crystallization of polyethylene glycol.
- 3. The method of claim 1 wherein (c) comprises from 5% to 25% by weight based on (a)+(c) of the polyurethane.
- 4. The method of claim 1 wherein the nonionic polyurethane is soluble in water at any mixing ratio at 20° C.
- 5. The method of claim 1 wherein the nonionic polyurethane is present as a solution in water up to 70% by weight of nonionic polyurethane, based on the weight of the solution.
- 6. The method of claim 1 wherein the nonionic polyurethane has a specific viscosity of 0.5 to 6.0 at 1% by weight in an aqueous solution at 2° C.
- 7. The method of claim 1 wherein the nonlonic polyurethane has a melt viscosity at 175° C. of more than 3 Pas.
- 8. The method of claim 1 wherein n is 20 to 300 and m is 20 to 300.
- 9. The method of claim 1 wherein the (c) moiety comprises residues of a diol having a solubility in water not greater than 2 grams/100 grams of water.
- 10. The method of claim 1 wherein the nonionic polyurethane is applied as an aqueous solution containing from 1% to 40% by weight of the nonionic polyurethane.
- 11. The method of claim 1 wherein the nonlonic polyurethane has a weight average molecular weight of from 10,000 to 200,000.
- 12. The method of claim 1 wherein the nonionic polyurethane is formed from a mixture wherein a molar ratio of the diol to diisocyanate is in a range of 1:0.95 to 1:1.25.
- 13. The method of claim 1 wherein the nonionic polyurethane is formed from a mixture wherein a molar ratio of diol to diisocyanate is in a range of 1:95 to 1:1.12.
- 14. The method of claim 1 wherein the nonionic polyurethane is formed from a mixture wherein a molar ratio of diol to diisocyanate is in a range of 1.0:0.98 to 1:1.1.
- 15. The method of claim 1 wherein the (b) group of the nonionic polyurethane comprises residue of m-tetramethyl xylylene diisocyanate.
- 16. The method of claim 1 wherein the nonionic polyurethane has been chain extended.
- 17. The method of claim 1 wherein the substrate is wallpaper or a label.
- 18. The method of claim 1 wherein the nonionic polyurethane is applied as a hotmelt adhesive.
- 19. The method of claim 1 wherein the nonionic polyurethane is applied as a solvent based adhesive.
- 20. The method as claimed in claim 2 wherein the nonionic polyurethane has a degree of crystallization of from 30% to 65%.
- 21. The method of claim 2 wherein the (c) unit comprises from 5% to 30% by weight based on (a)+(c) of the polyurethane.
- 22. The method as claimed in claim 1 wherein the equivalent ratio of (a) to (c) is greater than 1:1.
- 23. The method as claimed in claim 1 wherein (c) comprises a hydrophobic polyoxyalkylene moiety wherein the alkylene group contains 3 or 4 carbon atoms.
Priority Claims (1)
Number |
Date |
Country |
Kind |
P 42 42 687 |
Dec 1992 |
DE |
|
Parent Case Info
This application is a divisional of U.S. application Ser. No. 08/448,543, filed Jul. 27, 1995, issued as U.S. Pat. No. 6,399,735, which is a 371 of PCT/EP93/03526, filed Dec. 14, 1993; claiming priority of German application number P 4242687.1, filed Dec. 17, 1992: the entire contents of which are incorporated herein by reference.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3539482 |
Stewart |
Nov 1970 |
A |
6399735 |
Fischer et al. |
Jun 2002 |
B1 |
Foreign Referenced Citations (1)
Number |
Date |
Country |
1127082 |
Apr 1962 |
DE |