Ether carboxylic acids based on alkoxylated styrylphenols

1. A process for forming a film on a metal surface, said process comprising contacting the metal surface with a water-miscible fluid comprising the compound of the formula (1)

in which

A is C 2 - to C 4 -alkylene,

B is C 1 - to C 4 -alkylene,

x is a number from 1 to 3, and

y is a number from 1 to 100.

2. The process of claim 1 , wherein the water-miscible fluid is selected from the group consisting of cutting fluid, cleaning liquid, and surface treatment fluid.

3. The process of claim 1 , in which A is propylene or ethylene.

4. The process of claim 1 , in which the group (A-O) y is a mixed alkoxy group having a radical selected from the group consisting of ethylene, propylene, butylenes, and mixtures thereof.

5. The process of claim 1 , in which the group (A-O) y is a mixed alkoxy group which contains ethylene, propylene and butylene radicals, and in which the molar ratio of the groups derived from ethylene oxide to the groups derived from propylene oxide or butylene oxide is between 10:1 and 1:1.

6. The process of claim 1 , in which y is a number between 2 and 70.

7. The process of claim 1 , in which x is 2 or 3.

8. The process of claim 1 , in which the compound of formula (1) is in the form of a salt according to formula (2)

in which

A is C 2 - to C 4 -alkylene,

B is C 1 - to C 4 -alkylene.

x is a number from 1 to 3, and

y is a number from 1 to 100, and

R is an ammonium ion of the formula NR 1 R 2 R 3 R 4 , where R 1 , R 2 , R 3 and R 4 , independently of one another, are selected from the group consisting of H, C 1 - to C 22 -alkyl, C 6 - to C 18 -aryl, C 7 - to C 22 -alkylaryl, C 1 - to C 22 -alkenyl, and mixtures thereof, which may contain heteroatoms selected from the group consisting of N, P, O, S, and mixtures thereof.