Fluorochemical composition for treatment of a fibrous substrate

Abstract

Fluorochemical composition for rendering fibrous substrates oil repellent, water repellent, and/or stain or soil repellent. The composition comprises a dispersion or a solution of a fluorinated compound which comprises the reaction product of the following: (i) one or more fluorinated polyethers according to the formula: R f QT k   (I) wherein R f represents a monovalent perfluorinated polyether group having a number average molecular weight of at least 750 g/mol, Q represents a chemical bond or a divalent or trivalent organic linking group, T represents a functional group capable of reacting with an isocyanate, and k is 1 or 2; (ii) one or more polyoxyalkylene diols; (iii) one or more short chain perfluoroalkyl alcohols; (iv) one or more isocyanate component selected from a polyisocyanate compound that has at least 3 isocyanate groups or a mixture of polyisocyanate compounds wherein the average number of isocyanate groups per molecule is more than 2; (v) optionally one or more isocyanate blocking groups; and (vi) optionally one or more co-reactants capable of reacting with an isocyanate group. Also, a method of applying such composition to substrates, e.g., fibrous substrates.

1 . A fluorochemical composition comprising a dispersion or a solution of a fluorinated compound, wherein said fluorinated compound comprises the reaction product of a combination of reactants comprising:
 (i) one or more fluorinated polyethers according to the formula:
   R f QT k   (I) 
 wherein R f  represents a monovalent perfluorinated polyether group having a number average molecular weight of at least 750 g/mol, Q represents a chemical bond or a divalent or trivalent organic linking group, T represents a functional group capable of reacting with an isocyanate, and k is 1 or 2; 
   (ii) one or more polyoxyalkylene diols;   (iii) one or more short chain perfluoroalkyl alcohols;   (iv) one or more isocyanate component selected from a polyisocyanate compound that has at least 3 isocyanate groups or a mixture of polyisocyanate compounds wherein the average number of isocyanate groups per molecule is more than 2;   (v) optionally one or more isocyanate blocking group; and   (vi) optionally one or more co-reactants capable of reacting with an isocyanate group;   
       wherein less than about 15% of the isocyanate groups are reacted with said fluorinated polyether, at least about 5% of the isocyanate groups are reacted with said polyoxyalkylene diol, at least about 35% of the isocyanate groups are reacted with said short chain perfluoroalkyl alcohol, and less than about 15% of the isocyanate groups are reacted with said isocyanate blocking group. 
     
     
         2 . The fluorochemical composition of  claim 1  wherein said composition is free of perfluoroaliphatic groups of more than 6 carbon atoms other than perfluorinated end groups of a perfluorinated polyether moiety and/or perfluorinated polyether groups having a number average molecular weight of less than 750 g/mol or wherein said composition contains said perfluoroaliphatic groups of more than 6 carbon atoms in an amount of not more than about 10% by weight based on the total weight of perfluoroaliphatic groups other than end groups of a perfluorinated polyether moieties and/or contains said perfluorinated polyether groups having a number average molecular weight of less than 750 g/mol in an amount of not more than about 10% by weight based on the total weight of perfluorinated polyether moieties in the fluorochemical composition. 
     
     
         3 . The fluorochemical composition of  claim 1  wherein R f  in formula (I) is a perfluoropolyether group derived from a polycondensation of hexafluoropropylene oxide. 
     
     
         4 . The fluorochemical composition of  claim 1  wherein R f  in formula (I) corresponds to the formula:
   R f1 OR f2 (R f3 ) q      
       wherein R f1  represents a perfluorinated alkyl group, R f2  represents a perfluorinated polyalkyleneoxy group consisting of perfluorinated alkyleneoxy groups having 2 or 3 carbon atoms or a mixture of such perfluorinated alkylene oxy groups, R f3  represents a perfluorinated alkylene group, and q is 0 or 1. 
     
     
         5 . The fluorochemical composition of  claim 4  wherein R f2  corresponds to the formula:
   [CF(CF 3 )CF 2 O] n      
       wherein n is an integer of 3 to 25. 
     
     
         6 . The fluorochemical composition of  claim 4  wherein R f3  is CF(CF 3 ), q is 1, and R f2  corresponds to the formula:
   [CF(CF 3 )CF 2 O] n      
       wherein n is an integer of 3 to 25. 
     
     
         7 . The fluorochemical composition of  claim 1  wherein T is selected from the group consisting of hydroxy and amino groups. 
     
     
         8 . The fluorochemical composition of  claim 1  wherein said fluorinated polyether of formula (I) corresponds to the formula:
   R f1 O[CF(CF 3 )CF 2 O] n CF(CF 3 )AQ 1 T k      
       wherein R f1  represents a perfluorinated alkyl group, n is an integer of 3 to 25, A is a carbonyl group or CH 2 , Q 1  is a chemical bond or an organic divalent or trivalent linking group, and T represents a functional group capable of reacting with an isocyanate, and k is 1 or 2. 
     
     
         9 . The fluorochemical composition of  claim 1  wherein the fluorinated polyether compound corresponds to the formula:
   R f1 O [CF(CF 3 )CF 2 O] n CF(CF 3 )COXR a (OH) k      
       wherein R f1  represents a perfluorinated alkyl group, n is an integer of 3 to 25, X represents O or NR b  with R b  representing hydrogen or an alkyl group of 1 to 4 carbon atoms, R a  represents an alkylene group having 1 to 15 carbon atoms, and k is 1 or 2. 
     
     
         10 . The fluorochemical composition of  claim 1  wherein said organic linking group Q is selected from the group consisting of alkylene, oxyalkylene, aminoalkylene, amidoalkylene, carboxyalkylene. 
     
     
         11 . The fluorochemical composition of  claim 1  wherein said polyoxyalkylene diol is a polyoxypropylene diol having a number average molecular weight of from about 400 to about 2200. 
     
     
         12 . The fluorochemical composition of  claim 1  wherein said optional co-reactant has the formula:
   (R f4 ) x L(Y) y   (IV)   
       wherein R f4  is a perfluoroaliphatic group having 3 to 6 carbon atoms; L is a non-fluorinated organic divalent or multivalent linking group; Y represents a functional group having a Zerewitinoff hydrogen; x is an integer of from 1 to 20; and y is 1 or 2. 
     
     
         13 . The fluorochemical composition of  claim 12  wherein R f4  is C 4 F 9 —, x is 1, and y is 1. 
     
     
         14 . The fluorochemical composition of  claim 1  wherein said isocyanate component comprises an aliphatic polyisocyanate. 
     
     
         15 . The fluorochemical composition of  claim 1  wherein said isocyanate blocking group is butanone oxime. 
     
     
         16 . The fluorochecmial composition of  claim 1  wherein said co-reactant comprises a monofunctional alcohol, a monofunctional amine, a polyol, or a polyamine. 
     
     
         17 . The fluorochemical composition of  claim 1  wherein said co-reactant comprises a polyoxyalkylene having 2 or 3 carbon atoms in the oxyalkylene groups and having 1 group capable or reacting with an isocyanate. 
     
     
         18 . The fluorochemical composition of  claim 1  wherein said non-fluorinated organic compound comprises one or more non-fluorinated organic compounds having only one functional group capable of reacting with an isocyanate group and one or more non-fluorinated organic compounds having two functional groups capable of reacting with an isocyanate group. 
     
     
         19 . The fluorochemical composition of  claim 1  wherein said fluorochemical composition is dispersed in water and wherein the number average particle size of the dispersed fluorinated polyether compound is from about 50 nm to about 400 nm. 
     
     
         20 . The fluorochemical composition of  claim 1  wherein said fluorinated polyether compound is dispersed in water and wherein the aqueous dispersion contains a surfactant. 
     
     
         21 . The fluorochemical composition of  claim 1  wherein the amount of fluorinated polyether compound in the composition is from about 0.1% by weight to about 10% by weight. 
     
     
         22 . The fluorochemical composition of  claim 1  further comprising a non-fluorinated organic compound, wherein the non-fluorinated organic compound is capable of improving relative to the fluorochemical composition without said non-fluorinated organic compound, the oil repellency or water repellency that can be achieved by the fluorochemical composition on a fibrous substrate or the durability of one or both of the repellency properties 
     
     
         23 . The fluorochemical composition of  claim 1  wherein said isocyanate blocking group is selected from the group consisting of arylalcohols; lactams; oximes, bisulfites; and triazoles. 
     
     
         24 . A method of treatment of a fibrous substrate, comprising applying to the fibrous substrate a fluorochemical composition of  claim 1 . 
     
     
         25 . The method of  claim 24  wherein the amount of the fluorochemical composition applied is such that the amount of fluorinated polyether compound is from about 0.2% by weight to about 3% by weight relative to the weight of the fibrous substrate.