Flame-Retardant plastics molding composition
The invention relates to a flame-retardant plastics molding composition containing from 65 to 90% by weight, based on the total amount of the molding composition, of an olefin polymer and from 10 to 35% by weight, based on the total amount of the molding composition, of a flame retardant system, containing from 40 to 80% by weight of piperazine polyphosphate which has an average chain length of from 2.2 to 1000 phosphate units (component A), from 20 to 60% by weight of melamine cyanurate, melamine borate or condensed melamine (component B), from 0 to 2% by weight of polytetrafluoroethylene (component C) and from 0 to 40% by weight of ammonium polyphosphate (component D).
1 . A flame-retardant plastics molding composition comprising from 65 to 90% by weight, based on the total amount of the molding composition, of at least one olefin polymer and from 10 to 35% by weight, based on the total amount of the molding composition, of a flame retardant system, wherein the flame retardant system includes:
from 40 to 80% by weight of piperazine polyphosphate having an average chain length of from 2.2 to 1000 phosphate units (component A),
from 20 to 60% by weight of melamine cyanurate, melamine borate or condensed melamine (component B),
from 0 to 2% by weight of at least one anti-dripping agent (component C) and
from 0 to 40% by weight of ammonium polyphosphate (component D).
2 . The molding composition as claimed in claim 1 , wherein the flame retardant system includes:
from 60 to 80% by weight of piperazine polyphosphate having an average chain length of from 2.2 to 1000 phosphate units (component A),
from 20 to 39.9% by weight of melamine cyanurate, melamine borate or condensed melamine (component B),
from 0.1 to 2% by weight of the at least one anti-dripping agent, wherein the at least one anti-dripping agent is polytetrafluoroethylene (component C) and
from 0 to 10% by weight of ammonium polyphosphate (component D).
3 . The molding composition as claimed in claim 1 , wherein the flame retardant system includes:
from 40 to 50% by weight of piperazine polyphosphate having an average chain length of from 2.2 to 1000 phosphate units (component A), from 20 to 39.9% by weight of melamine cyanurate, melamine borate or condensed melamine (component B),
from 0.1 to 2% by weight of the at least one anti-dripping agent, wherein the at least one anti-dripping agent is polytetrafluoroethylene (component C) and
from 20 to 40% by weight of ammonium polyphosphate (component D).
4 . The molding composition as claimed in claim 1 , wherein the at least one olefin polymer comprises polyethylene, polypropylene or mixtures thereof.
5 . The molding composition as claimed in claim 1 , wherein the piperazine polyphosphate has the following chain length distribution:
chain length 1
from 0 to 10%
chain length 2
from 0 to 30%
chain length 3
from 0 to 30%
chain length 4
from 0 to 90%
chain length 5
from 0 to 25%
chain length 6
from 0 to 25%
chain length 7
from 0 to 40%
chain length 8 and longer
from 0 to 40%.
6 . The molding composition as claimed in claim 1 , wherein the at least one antidripping agent comprises fluorinated polymers.
7 . The molding composition as claimed in claim 1 , wherein the ammonium polyphosphate (component D) is coated with from 0.5 to 25%, based on its weight, of a coating composition.
8 . The molding composition as claimed in claim 7 , wherein the coating composition is a cured melamine/formaldehyde resin or a cured epoxy resin.
9 . The molding composition as claimed in claim 1 , wherein the piperazine polyphosphate has a median particle size (d50) of <100 μm.
10 . The molding composition as claimed in claim 1 , wherein the piperazine polyphosphate has a median particle size (d50) of <30 μm.
11 . The molding composition as claimed in claim 6 , wherein the fluorinated polymers is selected from the group consisting of polytetrafluoroethylene (PTFE), alkali metal or alkaline earth metal salts of perfluoroalkanesulfonic acid and mixtures thereof.