Low molecular weight brominated polymers and their use in thermoplastic formulations
AssigneeAlbemarle Corporation
InventorsWilliam J. Layman, Jr., Arthur G. Mack, Charles H. Kolich, Govindarajulu Kumar
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Abstract
This invention relates flame retardant compositions containing low molecular weight brominated anionic, chain transfer, vinyl aromatic polymers, hereinafter “ACTVAP”. The compositions can accommodate high bromine content while still exhibiting a low thermally labile bromine content. The compositions have glass transition temperatures, Tg, that are predictive of acceptable melt flows and heat distortion temperatures (HDT) in HIPS and ABS based formulations substrates. The compositions, are suitable flame retardant candidates for use in thermoplastic formulations, e.g. polystyrene and ABS formulations.
Claims28
A flame retardant composition comprising a brominated polymer distribution having a brominated monoadduct content, where said brominated monoadduct content does not exceed about 25 GPC area %, wherein the composition:
- (i) contains above 72 wt % bromine;
- and (ii) contains less than about 1,000 ppm (weight/weight) thermally labile Br as determined by the Thermally Labile Bromine Test, the wt % and ppm values being based upon the total weight of the composition, wherein said polymer distribution is an anionic, chain transfer, vinyl aromatic polymer (ACTVAP) distribution having a chain length distribution of individual polymer constituents prior to bromination having the general formula:
- Ar—CRH[—CH2CH(Ar)]n-CH2CH2—Ar,
- wherein Ar is a phenyl group, R is a C1-C4 alkyl group or hydrogen and n is the number of repeating monomer units;
- wherein each phenyl group in the brominated polymer distribution contains from about 2 to about 5 bromine substituents per phenyl group on an individual, not average, basis, wherein the brominated ACTVAP distribution comprises at least about 97 wt % of the total weight of the flame retardant composition, with the remainder being by-product impurities, wherein the Tg value of the brominated composition is within the range of from about 35° C. to about 165° C.;
- and wherein the composition GPC Mw is in the range of from about 1250 to about 14,000 Daltons, and GPC Mn is in the range of from about 1070 to about 8,200 Daltons and a PD less than about 2.2.
A flame retardant composition comprising a brominated polymer (ACTVAP) distribution having a brominated monoadduct content, where said brominated monoadduct content does not exceed about 25 GPC area %, wherein the composition:
- (i) has a glass transition temperature (Tg) within the range of from about 75° C. to about 135° C.;
- (ii) contains above 72 wt % bromine;
- and (iii) contains less than about 1,000 ppm (weight/weight) thermally labile Br as determined by the Thermally Labile Bromine Test;
- the wt % and ppm values being based upon the total weight of the composition, wherein said polymer distribution is an anionic, chain transfer, vinyl aromatic polymer (ACTVAP) distribution having a chain length distribution of individual polymer constituents prior to bromination of the general formula:
- Ar—CRH[—CH2CH(Ar)]n-CH2CH2—Ar,
- wherein Ar is a phenyl group, R is a C1-C4 alkyl group or hydrogen and n is the number of repeating monomer units;
- wherein each phenyl group in the brominated polymer distribution contains from about 2 to about 5 bromine substituents per phenyl group on an individual, not average, basis;
- wherein the brominated ACTVAP distribution comprises at least about 97 wt % of the total weight of the flame retardant composition, with the remainder being by-product impurities, and wherein the composition GPC Mw is in the range of from about 1250 to about 14,000 Daltons, and GPC Mn is in the range of from about 1070 to about 8,200 Daltons and a PD less than about 2.2.
Dependencies are inferred from the claim text.