# US 7,612,156 B2 · Polymers of bromostyrenes having controlled molecular weight

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,612,156 B2
- Document ID: US7612156B2
- Status: Granted
- Kind: B2
- Application number: 11/241,535
- Filed: 2005-09-30
- Published: 2006-04-13
- Granted: 2009-11-03
- Earliest claimed: 2004-09-30
- Assignees: Chemtura Corporation
- Inventors: Wayne Meyer; Jennifer L. Bohan; Larry D. Timberlake; James D. Siebecker
- Web page: https://patentgrep.com/patent/US7612156B2

## CPC

- C08F 12/32: containing two or more rings
- C08F 8/20: Halogenation
- C08F 8/22: by reaction with free halogens
- C08F 12/21: {Bromine}
- C08F 112/08: Styrene
- C08L 77/00: Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain (of polyhydrazides C08L79/06; of polyamideimides or polyamide acids C08L79/08); Compositions of derivatives of such polymers
- C08F 220/325: {containing glycidyl radical, e.g. glycidyl (meth)acrylate}
- C08K 7/14: Glass
- C08L 25/18: Homopolymers or copolymers of aromatic monomers containing elements other than carbon and hydrogen
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)

## Abstract

A controlled molecular weight polymer of styrene is provided having bromine substituted thereon. Control of molecular weight is achieved by the use of alpha-methyl styrene dimer as a chain transfer agent. The brominated polymer of styrene is useful as a flame retardant, particularly for polyamides giving improved properties including color retention after molding.

## Claims

### Claim 1

Polymers of ar-bromostyrene monomers having the following general structure
where R is H and x is 3, where the polymers have an assigned weight average molecular weight (MW) compared with a polystyrene standard as measured by gel permeation chromatography of from about 11,000 to about 60,000, wherein the polymers further comprise residues of α-methyl styrene dimer.

### Claim 2 (depends on 1)

The polymers of claim 1 further comprising units derived from copolymerization with a comonomer selected from the group consisting of glycidyl(meth)acrylate, maleic anhydride, hydroxyethylmethacrylate, acrylic acid, ar-amino substituted styrene, styrene sulfonic acid, salts of styrene sulfonic acid and mixtures thereof.

### Claim 3 (depends on 1)

The polymers of claim 1 further comprising units derived from copolymerization with a comonomer selected from the group consisting of styrene, butadiene acrylonitrile, methyl-(meth)acrylate, divinyl benzene, isoprene, n-butylacrylate, α-methyl styrene, p-methyl styrene and mixtures thereof.

### Claim 4 (depends on 1)

The polymers of claim 1 in which the α-methyl styrene dimer residue bears at least one aromatically bound polar compatibilizing group chosen from the group of —NH2, —N═C═O, amines, carboxylic acids, salts of carboxylic acids, amides, esters and epoxides.

### Claim 5

Polymers of ar-bromostyrene monomers having the following general structure
where R is H and x is 3, where the polymers have an assigned weight average molecular weight of from about 11,000 to about 60,000, wherein the polymers retain at least 88% of their mass after 20 minutes and at least 85% of their mass after 30 minutes when a 10 mg specimen is held at 330° C. under a nitrogen atmosphere.