FLAME RETARDANT COMPOSITION COMPRISING DENDRITIC POLYMERS

1 . A product obtained by reaction of:

a) At least one polyol selected from the group consisting of a linear or branched trihydric or tetrahydric alcohol, a linear pentahydric or hexahydric alcohol, a linear or cyclic C 4 -C 6 aldose and a linear or cyclic C 4 -C 6 ketose;

b) At least one melamine comprising compound; and

c) At least one dendritic polymer substituted by hydroxy groups.

2 . A product according to claim 1 obtained by reaction of:

a) A linear or branched trihydric or tetrahydric alcohol;

b) A melamine compound selected from the group consisting of melamine phosphate, melamine pyrophosphate and melamine polyphosphate; and

c) At least one dendritic polymer substituted by hydroxy groups.

3 . A product according to claim 1 obtained by reaction of:

a) A tetrahydric alcohol selected from the group consisting of pentaerythritol and dipentaerythritol;

b) A melamine compound selected from the group consisting of melamine phosphate, melamine pyrophosphate and melamine polyphosphate; and

c) A dendritic polymer of the polyester or polyamide type substituted by hydroxy groups.

4 . A product according to claim 1 obtained by reaction of:

a) A tetrahydric alcohol selected from the group consisting of pentaerythritol and dipentaerythritol;

b) A melamine compound selected from the group consisting of melamine phosphate and melamine pyrophosphate; and

c) A dendritic polymer of the polyester or polyamide type substituted by hydroxy groups.

5 . A product according to claim 1 obtained by reaction of:

a) Pentaerythritol;

b) Melamine phosphate; and

c) A dendritic polyester formed from an initiator compound selected from the group consisting of trimethylolpropane, pentaerythritol and ethoxylated pentaerythritol and chain-extending dimethylolpropionic acid or a polycondensation product of a cyclic carboxylic acid anhydride and diisopropanolamine.

6 . A flame retardant composition which comprises

A) A product obtained by reaction of:

a) At least one polyol selected from the group consisting of a linear or branched trihydric or tetrahydric alcohol, a linear pentahydric or hexahydric alcohol, a linear or cyclic C 4 -C 6 aldose and a linear or cyclic C 4 -C 6 ketose;

b) At least one melamine comprising compound; and

c) At least one dendritic polymer substituted by hydroxy groups; and

B) A polymer substrate.

7 . A flame retardant composition according to claim 6 , which comprises

A) A product obtained by reaction of

a) A tetrahydric alcohol selected from the group consisting of pentaerythritol and dipentaerythritol;

b) A melamine compound selected from the group consisting of melamine phosphate and melamine pyrophosphate; and

c) A dendritic polymer of the polyester or polyamide type substituted by hydroxy groups, and

B) A thermoplastic polymer substrate.

8 . A flame retardant composition according to claim 6 , which comprises

A) A product obtained by reaction of

a) Pentaerythritol;

b) Melamine phosphate; and

c) A dendritic polyester formed from an initiator compound selected from the group consisting of trimethylolpropane, pentaerythritol and ethoxylated pentaerythritol and chain-extending dimethylolpropionic acid or a polycondensation product of a cyclic carboxylic acid anhydride and diisopropanolamine; and

B) A thermoplastic polymer substrate selected from the group consisting of polyethylene, polypropylene and high impact polystyrene.

9 . A flame retardant composition according to claim 6 , which comprises d) further additives selected from the group consisting of polymer stabilizers and additional flame-retardants.

10 . Formed articles comprising the flame retardant composition according to claim 6 .

11 . A process for the preparation of a melamine-based flame retardant composition by reaction of a polyol and a melamine comprising compound,

characterized in that

a) At least one polyol selected from the group consisting of a linear or branched trihydric or tetrahydric alcohol, a linear pentahydric or hexahydric alcohol, a linear or cyclic C 4 -C 6 aldose and a linear or cyclic C 4 -C 6 ketose;

b) At least one melamine comprising compound; and

c) At least one dendritic polymer substituted by hydroxy groups;

are reacted in the presence of polymers.

12 . A process according to claim 11 , characterized in that components a), b) and c) are reacted in the presence of thermoplastic polymers by reactive extrusion methods.

13 . A process according to claim 12 , characterized in that components a), b) and c) are reacted in the presence of thermoplastic polymers in a twin-screw extruder.

14 . A process for imparting flame retardancy to a polymer, which process comprises the incorporation of a product according to claim 1 into the polymer.