Condensation polymers and intermediates therefor

Claim 1

A FIBRE-FORMING CONDENSATION POLYMER SELECTED FROM THE CLASS CONSISTING OF POLYESTERS AND POLYAMIDES, SAID POLYESTERS BEING FORMED BY THE CONDENSATION OF AT LEAST ONE COMPOUND SELECTED FROM THE CLASS CONSISTING OF SATURATED AND AROMATIC DICARBOXYLIC ACIDS, SATURATED AND AROMATIC GLYCOLS AND SATURATED AND AROMATIC HYDROXY MONOCARBOXYLIC ACIDS AND THEIR ESTER-FORMING DERIVATIVE, THERE BEING PRESENT COMPOUNDS CONTAINING BOTH CARBOXYL AND HYDROXY GROUPS OR THEIR ESTER-FORMING DERIVATIVES, TOGETHER WITH A MINOR PROPORTION OF A COMPOUND CONTAINING, AS THE ONLY REACTIVE GROUPS, MORE THAN TWO GROUPS SELECTED FROM THE CLASS CONSISTING OF CARBOXYL AND HYDROXYL GROUPS AND THEIR ESTER-FORMING DERIVATIVES, THE SAID GROUP BEING SEPARATED FROM EACH OTHER BY SATURATED CHAINS OF AVERAGE LENGTH AT LEAST 25 ATOMS, THE NATURES AND RELATIVE NUMBERS OF THE SAID REACTIVE GROUPS IN THE REACTANTS TAKEN AS A WHOLE BEING SUCH THAT SUBSTANTIALLY ALL THE LINKAGES IN THE FINAL PRODUCT ARE ESTER LINKAGES; AND SAID POLYAMIDES BEING FORMED BY THE CONDENSATION OF AT LEAST ONE COMPOUND SELECTED FROM THE CLASS CONSISTING OF SATURATED AND AROMATIC DICARBOXYLIC ACIDS, SATURATED AND AROMATIC DIAMINES AND SATURATED AND AROMATIC AMINO MONOCARBOXYLIC ACIDS AND THEIR AMIDE-FORMING DERIVATIVES, THEIR BEING PRESENT COMPOUNDS CONTAINING BOTH CARBOXYL AND AMIDE GROUPS AND THEIR AMIDE-FORMING DERIVATIVES, TOGETHER WITH A MINOR PROPORTION OF A COMPOUND CONTAINING , AS THE ONLY REACTIVE GROUPS, MORE THAN TWO GROUPS SELECTED FROM THE CLASS CONSISTING OF CARBOXYL AND AMINE GROUPS BEING SEPARATED FORMING DERIVATIVES, THE SAID GROUPS BEING SEPARATED FROM EACH OTHER BY SATURATED CHAINS OF AVERAGE LENGTH AT LEAST 25 ATOMS, THE NATURES AND RELATIVE NUMBERS THE SAID REACTIVE GROUPS IN THE REACTANTS TAKEN AS A WHOLE BEING SUCH THAT SUBSTANTIALLY ALL THE LINKAGES IN THE FINAL PRODUCT ARE AMIDE LINKAGES.