Process for the preparation of polyesters, including alkyl benzoylbenzoate

Claim 1

A PROCESS FOR THE PREPARATION OF A HIGHLY POLYMERIC POLYALKYLENE TEREPHTHALATE WHICH COMPRISES HEATING TO A TEMPERATURE OF 150*C. TO 265*C. A MIXTURE OF A GLYCOL OF THE FORMULA HO(CH2)NOH, WHERE N IS 2 TO 10, AND A COMPOUND TAKEN FROM THE GROUP CONSISTING OF TEREPHTHALIC ACID, DIALKYL TEREPHALATES WHEREIN SAID ALKYL RADICAL IS AN N-ALKYL RADICAL OF 1 THROUGH 4 CARBON ATOMS, TEREPHTHALIC CID CHLORIDE AND TEREPHTHALIC ACID BROMIDE IN THE PRESENCE OF AN ESTERIFICATION CATALYST TO FORM A MONOMERIC DIESTER, AND MIXING SAID DIESTER WITH A MONOMERIC ESTER TAKEN FROM THE GROUP CONSISTING OF ALKYL-O-BENZOYLBENZOATES ANDD ALKYL-O-(ALKYLBENZOYL)BENZOATES WHEREIN SAID ALKYL GROUPS CONTAIN 1 TO 4 CARBON ATOMS AND HEATING SUCH MIXTURE UNDER A REDUCED PRESURE OF 0.001 TO 7 MM. OF MERCURY AT A TEMPERATURE BETWEEN 150* C. AND 278* C. FOR A PERIOD OF 15 TO 600 MINUTES TO FORM A HIGHLY POLYMERIC ESTER HAVING A MOLECULAR WEIGHT BETWEEN 23,300 AN 33,500, SAID MONOMERIC ESTER BEING USED IN SUCH AN AMOUNT THAT THE BENZOYLBENOATE RADICAL OF SAID MONOMERIC ESTER CONSTITUTES FROM 1.94% TO 1.36% OF THE MOLECULAR WEIGHT OF THE POLYALKYLENE TEREPHTHALATE ECCLUSIVE OF THE BENZOYLBENZOATE RADICAL AND HEATING THE ADMIXTURE TO A TEMPERATURE BETWEEN 150*C. AND 278*C. AT A PRESSURE FROM 0.001 TO 7.0 MM. OF MERCURY FOR A PERIOD OF 15 TO 600 MINUTES.