Extender for treatment of fiber materials
View Patent ↗The use is described of aqueous dispersions in combination with fluoropolymers for oil- and water-repellent finishing of fiber materials. These dispersions have a long shelf life and contain a composition which is preparable by reaction of polyfunctional isocyanates with a deficiency of comparatively long-chain monohydric alcohols, subsequent reaction with a deficiency of a ketone oxime and final reaction with polyhydric alcohols or amino alcohols.
1. A method of treating fiber materials which comprises applying an aqueous dispersion comprising a composition A combined with a polymer which comprises perfluoroalkyl groups thereto, said composition A being prepared by the following successive steps of:
a) reacting a fluorine-free polyfunctional isocyanate mixture comprising about 80-95% by weight of a polymeric isocyanate and about 5-20% by weight of an alicyclic isocyanate and wherein each type of isocyanate has at least two free NCO groups per isocyanate molecule with a fluorine-free monohydric alcohol having 10 to 24 carbon atoms or a mixture of such alcohols by using 2 to 10 equivalents of NCO groups per equivalent of OH groups of the alcohol;
b) reacting the product obtained in step a) with a ketone oxime in such proportions that there are still free isocyanate groups present in the resultant product mixture; and
c) reacting the product mixture obtained in step b) with a fluorine-free organic amine which comprises two or three hydroxyl groups or with a fluorine-free polyhydric alcohol or with a mixture of such compounds in such proportions that the resultant product is free of isocyanate groups.
2. The method according to claim 1 , wherein one or more of said steps a), b) and c) are carried out in an anhydrous solvent.
3. The method according to claim 1 , wherein step a) utilizes a polymeric isocyanate which is obtained by reaction of a tolylene diisocyanate with 1,1,1-trimethylolpropane and diethylene glycol and which still comprises on Average2 or more NCO groups in the molecule.
4. The method according to claim 1 , wherein step b) utilizes 0.2 to 0.7 equivalent of oxime groups per equivalent of free isocyanate groups still present.
5. The method according to claim 1 , wherein the amine utilized instep c) is N-methyldiethanolamine or triethanolamine or a mixture thereof.
6. The method according to claim 1 , wherein the aqueous dispersion comprises one or more dispersants.
7. The method according to claim 1 , wherein the aqueous dispersion comprises at least one cationic dispersant.
8. The method according to claim 1 , wherein the fiber materials are textile fabrics in the form of wovens, formed-loop knits or nonwovens.