Brominated flame retardant, antimony oxide free polymer formulations
View Patent ↗Antimony free flame retardant compositions are prepared by combining a polymer resin, certain halogenated polyphenylene ether flame retardants and a non-brominated phenoxy oligomer or polymer such as a poly-phenylene ether, aryloxyester, or aryloxycarbonate. The present antimony free flame retardant compositions also typically have more desirable physical properties than similar compositions comprising antimony trioxide and other flame retardant. In particular embodiments, ATO free flame retardant HIPS and PC/ABS compositions are provided.
1. An antimony free flame retardant polymer composition comprising
a) a polymer resin, selected from a polyolefin; a polycarbonate, a rubber modified polystyrene, a polyamide, a polyurethane, polyacetal, epoxy resin, a natural rubber, a synthetic rubber and blends and copolymers thereof;
b) from about 1 to about 35% by weight based the weight of the antimony free flame retardant polymer composition of a mixture of brominated phenolic ether oligomers of formula I
wherein R 1 and R 2 are bromine, n is 3, 4 or 5, m is 3 or 4, and x is from 1 to 10,
having a halogen content of from about 65 to about 83 wt %, and which mixture comprises about 30 to about 50% 3-ring oligomers, 30 to 60% 4-ring oligomers, 1 to 15% 5-ring oligomers, less than 15% total of oligomers containing 6 or more phenyl rings and about 0 to about 2% 2-ring oligomers;
c) from 5 to about 85% by weight based on the weight of the antimony free flame retardant polymer composition of a polyphenylene ether of formula IIIa
wherein Y is a C 1-4 alkyl group and n is from about 12 to about 500; and
d) from 0 to about 10% by weight of a non-antimony flame retardant synergist or adjuvant, which flame retardant polymer composition is free of antimony compounds and iron compounds, and wherein polymer resin a) is not the same as the oligomer or polymer of c).
2. The composition according to claim 1 wherein a) comprises a polystyrene resin, b) is present in an amount of from 1 to 10 wt %, and c) is an ether of formula Ill present in an amount of from 30 to 60 wt %.
3. The composition according to claim 1 wherein a) comprises a polystyrene resin, b) is present in an amount of from 7 to 15 wt %, and c) is an ether of formula III present in an amount of from 10 to 25 wt %.
4. The composition according to claim 2 wherein a) comprises a high impact rubber modified polystyrene.
5. The composition according to claim 3 wherein a) comprises a high impact rubber modified polystyrene.
6. The composition according to claim 1 wherein the non-antimony flame retardant synergist or adjuvant is a melamine, melamine salt, a silicone, or a metal based synergist selected from metal oxides, hydroxides, sulphates, sulphites, sulphides, carbonates, carbides, nitrates, nitrites, nitrides, borates, silicates and phosphates of zinc, magnesium, aluminum, tin, titanium or calcium.
7. The composition according to claim 6 wherein the non-antimony flame retardant synergist or adjuvant is a melamine, melamine salt or a silicone and the polymer composition is free of the metal based synergists.
8. The composition according to claim 1 wherein the mixture of brominated phenolic ether oligomers b) comprises
from about 30 to about 45% of 3-ring oligomers,
from about 35 to about 60% of 4-ring oligomers,
from about 1 to about 10% of 5-ring oligomers,
from about 1 to about 10% of 6-ring oligomers,
from about 0.1 to about 4% of 7-ring oligomers, and
from about 0 to about 2.5% of 8-ring oligomers.