Polymeric flame retardant

A polymer composition comprising

• i) one or more styrene polymers and
• ii) one or more phosphorylated polyethers (ii-1) with from 0.5 to 40% by weight phosphorus content, the main chain of which is formed exclusively from carbon atoms and from oxygen atoms, and which has at least three terminal and/or pendant OH groups, where these have been substituted to some extent or
• entirely with at least one phosphorus-containing group (I),
• where the definitions of the symbols and indices are as follows:
• ˜ indicates the bond to the polymer skeleton of the polyether;
• Y is 0 or S;
• t is 0 or 1;
• R1 and R2, being identical or different, are H, C1-C18-alkyl, C2-C18-alkenyl, C2-C18-alkynyl, C3-C10-cycloalkyl, C6-C10-aryl, furyl, C6-C10-aryl-C1-C10-alkyl, OR3, SR3, NR3R4, COR3, COORS or CONR3R4, or R1 and R2 form, together with the phosphorus atom P, a 4-8-membered ring system;
• R3 and R4, being identical or different, are H, C2-C16-alkenyl, C3-C16-alkynyl, C3-C10-cycloalkyl, C6-C10-aryl, furyl, C6-C10-aryl-C1-C10-alkyl
• where aryl groups in the moieties R1, R2, R3, and R4 are unsubstituted or have substitution by from 1 to 3 C1-C4-alkyl and/or C1-C4-alkoxy groups,
• and/or
• polycarbonates (ii-2) comprising one or more phosphorus-containing groups, where the phosphorus-containing group is a group of the general formula (I).

A phosphorylated polyether (ii-1) with from 0.5 to 40% by weight phosphorus content, the main chain of which is formed exclusively from carbon atoms and from oxygen atoms, and which has at least three terminal and/or pendant OH groups, where these have been substituted to some extent or

• entirely with at least one phosphorus-containing group (I),
• where the definitions of the symbols and indices are as follows:
• ˜ indicates the bond to the polymer skeleton of the polyether;
• Y is 0 or S;
• t is 0 or 1;
• R1 and R2, being identical or different, are H, C1-C18-alkyl, C2-C18-alkenyl, C2-C18-alkynyl, C3-C10-cycloalkyl, C6-C10-aryl, furyl, C6-C10-aryl-C1-C10-alkyl, OR3, SR3, NR3R4, COR3, COORS or CONR3R4, or R1 and R2 form, together with the phosphorus atom P, a 4-8-membered ring system;
• R3 and R4, being identical or different, are H, C1-C16-alkyl, C2-C16-alkenyl, C3-C16-alkynyl, C3-C10-cycloalkyl, C6-C10-aryl, furyl, C6-C10-aryl-C1-010-alkyl and
• wherein aryl groups in the moieties R1, R2, R3, and R4 are unsubstituted or have substitution by from 1 to 3 C1-C4-alkyl and/or C1-C4-alkoxy groups.