Flame retarding linear polyesters and shaped articles thereof
AssigneeHoechst Aktiengesellschaft
InventorsHans-Jerg Kleiner, Manfred Finke, Ulrich Bollert, Walter Herwig
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Abstract
Flame-repellant linear polyesters are obtained by incorporating by condensation phosphorus-compounds having the formula ##EQU1## wherein R and R.sub.1 are organic radicals which may also contain hereto atoms into the linear polyesters, preferably those from terephthalic acid and ethylene glycol. These polyesters are materials of which flame-repellent filaments, fibers, sheets, press-moulded and injection-moulded articles may be made. Products of the invention can be used whereever especially acute risks of ignition and fire exist.
Claims8
A linear polyester which is the polycondensation product of a dicarboxylic acid, a diol and a flame-retarding carboxy-phosphinic acid monomer, said monomer being used in an amount of from 3 to 20 mol percent, based on the total amount of dicarboxylic acid and monomer, said monomer being a source of structural units in said polyester of the formula ##EQU10## wherein R is saturated, open-chain or cyclic alkylene, arylene or aralkylene having one to 15 carbon atoms, and may contain one or more hetero atoms selected from F, Cl, Br, O and S, and R.sub.1 is alkyl having up to six carbon atoms, aryl, or aralkyl and may contain one or more hetero atoms selected from F, Cl, Br, O and S, provided that in the R and R.sub.1 groups the O, if present, is the oxygen of an ether group, and the S, if present, is the sulfur of a thioether, sulfoxide, sulfone or sulfonate group.
A method of making a linear polyester which comprises polycondensing a dicarboxylic acid or a lower alkyl ester thereof with a diol in the presence of a flame-retarding phosphorus containing monomer of the general formula ##EQU11## or a lower alkyl ester or cyclic anhydride of said monomer in an amount of about 3 to 20 mole percent of the total acid components wherein the symbol R of said formula is saturated, open-chain or cyclic alkylene having one to 15 carbon atoms, arylene or aralkylene, and R.sub.1 of the formula is alkyl having up to 6 carbon atoms, aryl or aralkyl, and wherein R and R.sub.1 may further contain one or more hetero atoms selected from F, Cl, Br, O and S, provided that in the R and R.sub.1 groups the O, if present, is the oxygen of an ether group, and the S, if present, is the sulfur of a thioether, sulfoxide, sulfone or sulfonate group.
Dependencies are inferred from the claim text.