GB1401863A - Flame retardant polyester resin compositions - Google Patents

Abstract

1401863 Flame retardant polyester compositions GENERAL ELECTRIC CO 2 Nov 1972 50527/72 Heading C3R A flame retardant thermoplastic composition suitable for moulding comprises (a) a normally flammable high molecular weight linear polyester derived from glycol terephthalates or isophthalates having repeat units in which n is 2 to 4, and mixtures of such esters, or such esters including minor amounts of aliphatic dicarboxylic acid ester units and (b) a phosphorus-containing flame-retardant additive in a minor proportion based on the composition having the general formula wherein X is -O- or a carbon-to-phosphorus bond and (i) when X is -O-, R is brominated aryl and Y and G are brominated aryloxy groups; and (ii) when X is carbon-to-phosphorus, R is aryl, Y is aryl, oxyalkyl, oxycycloalkyl or oxyaryl and G is oxyaryl or a single or repeating unit of formula wherein R is aryl, A is divalent alkylene, cycloalkylene, arylene, or polyarylene radical, or a divalent poly-diarylene group of formula wherein R<SP>2</SP> is alkylene, alkylidene or cycloalkylidene of 1 to 18 carbon atoms, an oxygen, carbonyl, amino, sulphide, sulphoxide, sulphone or mono- or di-carboxylic aryl or alkylarylphosphonate linkage, or a divalent alkylene or alkylidene group of from 2 to 27 carbon atoms interrupted by one or more of an arylene, oxygen, carbonyl, amino, sulphide, sulphoxide, sulphone, or mono- or di-carbocyclic aryl or alkylaryl phosphonate linkage; Ar and Ar<SP>1</SP> are mono- or di-carbocyclic divalent arylene groups of 6 to 12 carbon atoms; R<SP>3</SP> is an alkyl or cycloalkyl group of 1 to 12 carbon atoms or a mono- or di-carbocyclic aryl or alkylaryl group of from 6 to 12 carbon atoms; c is 0 or from 1 to an integer equal to the number of replaceable hydrogens or R<SP>2</SP>; and a, b and c are 0 or whole numbers of from 1 to 6, provided that when b is a whole number other than 0, neither a nor c may be 0 and when b is 0 either a or c, but not both may be 0; and Z is hydrogen, alkyl, cycloalkyl or aryl; and when taken together, G and Y are divalent dioxyalkylene, dioxycycloalkylene or dioxyarylene groups. Preferred polyesters are polyethylene terephthalate and poly 1 : 4 butylene terephthalate. Additionally the compositions may contain a polytetrafluorethylene resin or a fumed colloidal silica in minor proportion. "High molecular weight polymer" is defined as having an intrinsic viscosity of at least about 0À4 dl./g. as measured at 25-30‹ C. in o chlorophenol tetrachlorethane 60/40 mixtures. Many examples are given and the products subjected to flame testing and oxygen index according to A.S.T.M. Poly 1,4-cyclohexylene dimethylene phenyl phosphonate is prepared by reacting 1,4-cyclo hexanedimethanol with phenyl phosphonic acid dichloride.