Claims
- 1. Process for tanning or retanning hide, skin or leather, characterized in that hide, skin or leather are treated with an aqueous solution which contains:
- (a) optionally methylolated water-soluble oligourethanes containing ionic groups which have a molecular weight of from 300 to 20,000, characterized in that the water-soluble oligourethanes contain no phenolic groups, no free NCO groups and no aziridine groups; and, optionally,
- (b) formaldehyde or a substance from which formaldehyde may be split off.
- 2. Process according to claim 1, characterized in that the oligourethane molecule contains hydrophilic polyether segments.
- 3. A process for tanning or retanning a substrate selected from the group consisting of animal pelts and leather comprising treating the substrate with an aqueous solution containing water-soluble oligourethanes containing ionic groups which have a molecular weight (M.sub.n) of from 300 to 20,000, characterized in that the water-soluble oligourethanes contain no free NCO groups, no phenolic groups and no aziridine groups.
- 4. The process of claim 3 wherein the oligourethanes are methylolated.
- 5. The process of claim 4 wherein the aqueous liquor contains from 0 to 100 wt.% based on the oligourethane of compounds selected from the group consisting of formaldehyde and compounds which split off formaldehyde.
- 6. The process of claim 5 wherein the formaldehyde supplying compounds are present in amounts of about 0.5 to 30 wt.% based on the oligourethane.
- 7. The process of claim 3 wherein the oligourethane molecules contain hydrophilic polyether segments.
- 8. The process of claim 3 wherein the oligourethane molecules contain ionic groups selected from the group consisting of: ##STR2## where R is a monovalent alkyl, cycloalkyl, aralkyl or aryl radical.
- 9. A process for tanning or retanning a substrate selected from the group consisting of animal pelts and leather comprising treating the substrate with an aqueous solution containing water-soluble oligourethanes containing ionic groups which have a molecular weight (M.sub.n) of from 300 to 20,000, characterized in that the water-soluble oligourethanes contain no free NCO groups, no phenolic groups and no aziridine groups, said water-soluble oligourethanes synthesized by a process comprising
- (a) reacting polyhydroxyl compounds selected from the group consisting of polyethers, polyesters and polycarbonates, with
- (b) polyisocyanates and
- (c) optionally chain-terminating agents wherein at least a portion of at least one of components (a), (b) and (c) contains at least one ionic group or at least one group which may be converted into an ionic group.
- 10. The process of claim 9 wherein the NCO/OH ratio maintained during the synthesis of the water-soluble oligourethanes is between 0.4 to 0.8.
- 11. The process of claim 9 wherein chain-terminating agents selected from the group consisting of polyols, amino alcohols and polyamines are used in the synthesis of the water-soluble oligourethanes and wherein the NCO/OH ratio maintained during the synthesis reaction is between 0.4 to 0.8.
- 12. The process of claim 9 wherein chain-terminating agents selected from the group consisting of monofunctional alcohols, monofunctional amines, monofunctional carboxylic acids, ureas and monofunctional isocyanates are used in the synthesis of the water-soluble oligourethanes and wherein the NCO/OH ratio maintained during the synthesis reaction is between 0.6 to 1.0.
- 13. The process of claim 12 wherein the chain-terminating agents are selected from the group consisting of monofunctional alcohols, monofunctional amines, monofunctional carboxylic acids and ureas.
- 14. The process of claim 9 wherein chain-terminating agents are used in the synthesis of the water-soluble oligourethanes, at least one of said chain-terminating agents selected from the group consisting of polyols, amino alcohols and polyamines and at least one of said chain-terminating agents selected from the group consisting of monofunctional alcohols, monofunctional amines, monofunctional carboxylic acids, ureas and monofunctional isocyanates, and wherein the NCO/OH ratio maintained during the synthesis is between 0.6 to 1.0.
- 15. The process of claim 9 wherein the polyhydroxyl compounds are polyethers.
Priority Claims (2)
Number |
Date |
Country |
Kind |
2416485 |
Apr 1974 |
DEX |
|
2504081 |
Jan 1975 |
DEX |
|
Parent Case Info
This application is a continuation-in-part of our copending application Ser. No. 561,809 filed Mar. 25, 1975, now abandoned.
US Referenced Citations (4)
Foreign Referenced Citations (2)
Number |
Date |
Country |
1,223,458 |
Jun 1960 |
FRX |
1,022,749 |
Jan 1958 |
DEX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
561809 |
Mar 1975 |
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