Highly compatible and non-migratory polymeric uv-absorber

An oligoester or polyester of formula (I)

• -[A-O-D-O]x— (I)
• in which
• x is a number from 1 to 50;
• A is a group of the formula (II)
• or has one of the meanings given for T;
• D is C4-C12 alkylene or said alkylene substituted by OH or interrupted by O or both substituted by OH and interrupted by O;
• L is C1-C18alkylene, C5-C12cycloalkylene, C3-C18alkenylene, or one of said residues substituted by phenyl, C7-C11alkylphenyl, C5-C12cycloalkyl, OH, halogen, C1-C18alkoxy, C5-C12cycloalkoxy, C3-C18alkenyloxy, or COOH;
• the R1 groups are independently of each other H, OR7 or OH, with the proviso that at least one of R1 or R13 is OH;
• the R7 groups are independently of each other hydrogen, C1-C12alkyl or a radical of formula -L-CO—O—R9;
• R9 is H, C1-C18alkyl or C2-C12hydroxyalkyl;
• R10 is hydrogen, C1-C4alkyl, Cl, phenyl or a group —OR7;
• R11 is hydrogen or methyl;
• R13 is hydrogen, methyl, OH or OR7;
• and
• T is the divalent acyl residue of an aliphatic or cycloaliphatic dicarboxylic acid of 13 to 60 carbon atoms;
• and which contains at least one moiety of formula (II) and at least one moiety T.