Derivatives of tris(2-hydroxyphenyl)methane, their preparation and use

A derivative of tris(2-hydroxyphenyl)methane, wherein the tris(2-hydroxyphenyl)methane derivative has the general formula (I):

• where the radicals R1, R2 and R have the following meaning:
• R:
• are independently of one another, 0 to 4 C1- to C30-hydrocarbon radicals per phenyl ring,
• R1:
• is a radical selected from the group consisting of H, OH, F, Cl, Br, I and C1- to C30-hydrocarbon groups,
• R2:
• are independently of one another, radicals of the general formula —(R5—O—)n—R6—X (III), where n is a number from 1 to 50, and where the radicals R5, independently of one another, are selected from the group consisting of radicals R7, R8 and R9
• where R6, X, R10 and R11, independently of one another, have the following meaning:
• R6:
• is a single bond or an alkylene group having 1 to 10 carbon atoms which can have optionally functional groups as substituents,
• X:
• is H or an acidic group or a radical which comprises at least one OH group,
• R10:
• is H or a C1- to C6-hydrocarbon radical,
• R11:
• is a group —(R5—O—)m—R6—X, where m is a number from 0 to 50,
• and where the total number z of all groups R5 in a radical R2 is 1 to 50, with the proviso that z is a number from 2 to 50, if at least one X is H.