The use of diglycidyl compounds in improved methods for preparing alkyd resins

Claim 1

A PROCESS FOR PRODUCING AN OIL-MODIFIED ALKYD RESIN COMPRISING THE STEPS: (1) ESTERIFYING AT A TEMPERATURE IN EXCESS OF 200*C. A POLYHYDRIC ALCOHOL, A POLYCARBOXYLIC ACID FREE OF NON-BENZENOID UNSATURATION AND A MONO-CARBOXYLIC MODIFIER SELECTED FROM THE GROUP CONSISTING OF FATTY ACIDS HAVING FROM 8 TO 18 CARBON ATOMS AND PARTIAL POLYHYDRIC ALCOHOL ESTERS THEREOF UNTIL AN ACID NUMBER BETWEEN ABOUT 15 AND 50 IS OBTAINED, SAID ESTERIFICATION PRODUCT BEING SUBSTANTIALLY FREE OF HYDROXYL GROUPS, THEREUPON, (2) REACTING TO COMPLETION AS INDICATED BY AN ACID NUMBER NOT GREATER THAN 13 AT A TEMPERATURE BETWEEN ABOUT 130*C. AND 260*C. THE ESTERIFICATION PRODUCT OF SAID STEP (1) WITH A DIGLYCIDYL ESTER OF A DICARBOXYLIC ACID ON THE BASIS OF FROM ABOUT 0.5:1.5 EQUIVALENTS OF OXIRANE OXYGEN AS REPRESENTED BY SAID ESTER PER EQUIVALENT OF UNCONDENSED CARBOXYL GROUPS CONTAINED BY THE ESTERIFICATION PRODUCT OF SAID STEP (1).