Mixture of fluorinated polyethers and use thereof as surfactant

1. A composition comprising an organic or aqueous liquid having dissolved or dispersed therein a mixture of fluorinated polyethers of the formula:

(R f ) n —X w —Z

wherein n is 1 or 2, w is 0 or 1, X is a divalent or trivalent organic linking group, Z is a polar group selected from the group consisting of an acid group or salt thereof, an ammonium group, an amine-oxide group and an amphoteric group, and R f represents a perfluorinated polyether group of the formula:

CF 3 CF 2 CF 2 —O—[CF(CF 3 )CF 2 O] k —CF(CF 3 )—

wherein k is at least 1;

said mixture of fluorinated polyethers having a weight average molecular weight between 750 g/mol and 5000 g/mol and the amount of perfluorinated polyether groups in said mixture where k is 2 or less, is not more than 10% by weight of the total amount of perfluorinated polyether groups in said mixture.

2. The composition according to claim 1 , wherein the organic liquid is selected from the group consisting of polar solvents selected from the group consisting of alcohols, ketones, esters, ethers and amides, non-polar solvents selected from the group consisting of aromatic and aliphatic hydrocarbon solvents and halogenated solvents selected from the group consisting of hydrofluoroethers, hydrofluorocarbons and chlorinated hydrocarbons.

3. The composition according to claim 1 , wherein the organic linking group corresponds to the formula —CONR 8 —(CH 2 ) s —, wherein R u is hydrogen or C 1-6 -alkyl or C 1-6 -kyl substituted by halogen, OH, or SH and s is 1 to 20.

4. The composition according to claim 1 , wherein Z corresponds to the formula:

wherein each of R 1 , R 2 and R 3 independently represents a hydrogen atom or a hydrocarbon group that may optionally be substituted, M represents a counter ion, r is 0 or 1, and when r is 0, one of R 1 , R 2 and R 3 represents a hydrocarbon group that is substituted with an acid group or wherein Z corresponds to the formula:

wherein R 4 and R 3 are independently C 1-6 -alkyl, C 1-6 -alkyl substituted by a halogen, a C 1-6 -alkoxy, NO 2 or CN group, or R 4 and R 5 join to form a 5 to 7 menibered ring that may contain one or more additional hetero atoms and that may be substituted by one or more C 1-6 -alkyl groups.

5. The composition according to claim 1 further comprising one or monomers capable of polymerization.

6. The composition according to claim 1 further comprising a fluorochemical compound capable of providing oil- and/or water repellency properties to a substrate.

7. A mixture of fluorinated polyethers of the formula:

(R r ) n —X w —Z

wherein n is 1 or 2, w is 0 or 1, X is a divalent or trivalent organic linking group, Z is a polar group selected from the group consisting of an ammonium group, an amine-oxide group and an amphoteric group, and R f represents a perfluorinated polyether group of the formula:

CF 3 CF 2 CF 2 —O—[CF(CF 3 )CF 2 O] k—CF(CF 3 )—

wherein k is at least 1;

said mixture of fluorinated polyethers having a weight average molecular weight between 750 g/mol and 5000 g/mol and the amount of perfluorinated polyether groups in said mixture where k is 2 or less, is not more than 10% by weight of the total amount of perfluorinated polyether groups in said mixture.

8. A method of altering the surface energy and/or interfacial free energy of a medium, said method comprising 1) providing a medium and 2) incorporating a fluorinated polyether composition therein, said fluorinated polyether composition comprising a mixture of fluorinated polyethers of the formula:

(R f ) n —X w —Z

wherein n is 1 or 2, w is 0 or 1, X is a divalent or trivalent organic linking group, Z is a polar group selected from the group consisting of an acid group or a salt thereof, an ammonium group, an amine-oxide group and an amphoteric group, and R f represents a perfluorinated polyether group of the formula:

CF 3 CF 2 CF 2 —O—[CF(CF 3 )CF 2 O] k —CF(CF 3 )—

wherein k is at least 1 ;

said mixture of fluorinated polyethers having a weight average molecular wcight between 750 g/mol and 5000 g/mol and the amount of perfluorinated polyether groups in said mixture where k is 2 or less, is not more than 10% by weight of the total amount of perfluorinated polyether groups in said mixture.

9. The method of claim 8 , wherein the organic linking group corresponds to the formula —CONR 6 —(CH 2 ) 9 —, wherein R a is hydrogen or C 1-6 -alkyl or C 1-6 -alkyl substituted by halogen, OH, or SH, and s is 1 to 20.

10. The method of claim 8 , wherein Z corresponds to the formula:

wherein each of R 1 , R 2 and R 3 independently represents a hydrogen atom or a hydrocarbon group that may optionally be substituted, M represents a counter ion, r is 0 or 1, and when r is 0, one of R 1 , R 2 , and R 3 represents a hydrocarbon group that is substituted with an acid group or wherein Z corresponds to the formula:

wherein R 4 and R 5 are independently C 1-6 -alkyl, C 1-6 -alkyl substituted by a halogen, a C 1-6 -alkoxy, NO 2 , or CN group, or R 4 and R 5 join to form a 5 to 7 memberod ring that may contain one or more additional hetero atoms and that may be substituted by one or more C 1-6 -alkyl groups.

11. The method of claim 8 , wherein said medium is a coating composition or fire-fighting agent.