FLAME RETARDANT HALOGENATED ARYL ETHER OLIGOMER COMPOSITIONS AND THEIR PRODUCTION
In a process for producing a flame retardant halogenated aryl ether oligomer composition, an aryl ether oligomer is combined with a liquid carrier having a boiling point lower than water to form a slurry or solution of the aryl ether oligomer in the carrier. A halogenating agent is included in the slurry or solution to form a reaction composition, which is reacted at a temperature between about 20° C. and about 80° C. to form a reaction product containing the desired halogenated aryl ether oligomer composition. Unreacted halogenating agent is removed from the reaction product and the reaction product is contacted with an aqueous medium at a temperature sufficient to drive off the liquid carrier and produce an aqueous slurry of the halogenated aryl ether oligomer composition. The desired halogenated aryl ether oligomer composition is then recovered from the aqueous slurry.
1 . A process for producing a flame retardant halogenated aryl ether oligomer composition, the process comprising:
(a) combining an aryl ether oligomer with a liquid carrier having a boiling point lower than water to form a slurry or solution of said aryl ether oligomer in said carrier;
(b) including a halogenating agent in said slurry or solution to form a reaction composition;
(c) reacting said reaction composition at a temperature between about 20° C. and about 80° C. to form a reaction product comprising the desired halogenated aryl ether oligomer;
(d) removing unreacted halogenating agent from the reaction product;
(e) contacting the reaction product with an aqueous medium at an elevated temperature sufficient to drive off the liquid carrier and produce an aqueous slurry of said halogenated aryl ether oligomer; and
(f) recovering the halogenated aryl ether oligomer from said aqueous slurry.
2 . The process of claim 1 , wherein said aryl ether oligomer comprises repeating monomeric units of the formula (I):
wherein R is alkyl, n is 0 to 3 and x is at least 2.
3 . The process of claim 2 , wherein x is 3 to 100,000.
4 . The process of claim 2 , wherein said aryl ether oligomer is produced by reacting a dihaloaryl compound with a diphenolic compound.
5 . The process of claim 4 , wherein said aryl ether oligomer comprises a mixture of oligomeric compounds having the following formula (II):
wherein n is 0 or at least 1; where R 1 is H, OH or halogen; and where R 2 is H, OH, halogen or a phenoxy group of the formula (III):
wherein R 3 is OH or halogen;
wherein said oligomeric mixture comprises compounds of formula (II) with three benzene rings and compounds of formula (II) with more than three benzene rings;
wherein the average molecular weight of the compounds of formula (II) is at least 400; and
wherein the compounds of formula (II) comprise, on average, from 2 wt % to 35 wt % halogen.
6 . The process of claim 5 , wherein said oligomeric mixture comprises less than 30 wt % of compounds of formula (II) with two benzene rings and less than 1 wt % of compounds of formula (II) with one benzene ring.
7 . The process of claim 5 , wherein said oligomeric mixture has a weight average molecular weight (Mw) of about 600 to about 2000 and a polydispersity of about 1.4 to about 2.5 as measured by GPC chromatography versus a polystyrene standard.
8 . The process of claim 5 , wherein said oligomeric mixture is produced by reacting dibromobenzene with at least one dihydroxybenzene.
9 . The process of claim 5 , wherein said oligomeric mixture is produced by reacting dibromobenzene with at least one dihydroxybenzene in a molar ratio of dibromobenzene to dihydroxybenzene greater than 1.
10 . The process of claim 5 , wherein said oligomeric mixture is produced by reacting dibromobenzene with resorcinol.
11 . The process of claim 1 , wherein said liquid carrier is selected from methylene chloride, chloroform, dibromomethane, 1,2-dichloroethane and bromochloromethane.
12 . The process of claim 1 , wherein bromine comprises the liquid carrier and the halogenating agent and said contacting (e) removes unreacted halogenating agent from the reaction product.
13 . The process of claim 1 , wherein the unreacted bromine is removed by a distillation step separate from said contacting (e).
14 . The process of claim 1 , wherein aqueous medium is water.
15 . The process of claim 1 , wherein aqueous medium is a dilute acid solution.
16 . The process of claim 1 , further comprising neutralizing the reaction product with a reducing agent capable of reacting with unreacted halogenating agent.
17 . The process of claim 1 , wherein (e) is effected by adding water to the reaction product to form an aqueous product mixture and then raising the temperature of said mixture.
18 . The process of claim 1 , wherein (e) is effected by adding said reaction product to water at a temperature between 70-100° C. to flash off said solvent.
19 . The process of claim 1 , wherein at least part of said reacting (b) is conducted in the presence of a Lewis acid catalyst.
20 . The process of claim 19 , wherein said Lewis acid catalyst is aluminum chloride.
21 . A flame retardant halogenated aryl ether oligomer composition comprising a mixture of oligomeric compounds having the following formula (IV):
wherein n is 0 or at least 1; where R 1 is H, OH or halogen; X is halogen, each of m and p is at least 1, and where R 2 is H, OH, halogen or a phenoxy group of the formula (V):
wherein R 3 is OH or halogen and q is at least 1;
wherein said oligomeric mixture comprises compounds of formula (IV) with three benzene rings and compounds of formula (IV) with more than three benzene rings;
wherein the average molecular weight of the compounds of formula (IV) is at least 1000; and
wherein the compounds of formula (IV) comprise, on average, from 55 wt % to 82 wt % halogen.
22 . A flame retardant polymer composition comprising (i) a flammable macromolecular material and (ii) a flame retardant halogenated aryl ether oligomer composition as claimed in claim 21 .
23 . The polymer composition of claim 22 , wherein the macromolecular material comprises at least one of a polyester, a polyamide and an olefinic resin.