Process for preparation of pentaerythritol and polypentaerythritol ester plasticizers

Claim 1

AN ESTERIFICATION PROCESS WHICH COMPRISES REACTING (A) AT LEAST ONE MEMBER OF THE CLASS CONSISTING OF PENTAERYTHRITOL AND POLYPENTAERYTHRITOLS AVERAGING TO TRIPENTAERYTHRITOL WITH (B) AN EXCESS OF AN ACID COMPONENT FROM THE CLASS CONSISTING OF A BRANCHED ALKANOIC ACID CONTAINING SIX CARBON ATOMS AND A MIXTURE OF ALKANOIC ACIDS, EACH ACID IN SAID MIXTURE HAVING A CONTENT OF 4 TO 8 CARBON ATOMS, SAID MIXTURE OF ACIDS FURTHER HAVING AN AVERAGE CONTENT OF 5 TO 6.5 CARBON ATOMS AND CONTAINING FROM ABOUT 50 TO ABOUT 100 PERCENT BY WEIGHT OF BRANCHED ACID COMPONENT TO THE TOTAL ALKANOIC ACID MIXTURE, BY HEATING WITHIN A TEMPERTURE RANGE OF ABOUT 120* TO ABOUT 240*C. AND IN THE PRESENCE OF ACTIVATED CARBON UNTIL THE REACTION MIXTURE HAS A DROXYL NUMBER NOT EXCEEDING ABOUT 5.0, STRIPPING SAID REACTION MIXTURE BY HEATING WITHIN SAID TEMPERATURE RANGE UNDER A REDUCED PRESSURE NOT EXCEEDING 80 MM. OF MERCURY UNTIL THERE IS OBTAINED A PRODUCT HAVING AN ACID NUMBER NOT EXCEEDING 0.5, AND ISOLATING SAID PRODUCT.