Alkyd resins and their preparation from reaction mixtures comprising a polymethylolalkanoic acid

Claim 1

IN THE PREPARATION OF ALKYD RESINS INVOLVING HEAT ING A REACTION MIXTURE COMPRISING POLYHYDRIC ALCOHOL HAVING AT LEAST THREE HYDROXYL GROUPS AND POLYCARBOXYLIC ACID, THE IMPROVEMENT COMPRISING THE STEP OF INCLUDING IN SAID REACTION MIXTURE: (A) AN UNSATURATED FATTY ACID AND (B) AT LEAST ONE POLYMETHYLOLALKANOIC ACID SELECTED FROM THE GROUP CONSISTING OF TRIMETHYLOLACETIC ACID AND DIMETHYLOLALKANOIC ACIDS HAVING FROM FIVE TO SEVEN CARBON ATOMS; THE AMOUNT OF UNSATURATED FATTY ACID IN MOLS, BEING SUBSTANTIALLY EQUIVALENT TO THE QUANTITY (X-2) TIMES THE NUMBER OF MOLS OF POLYHYDRIC ALCOHOL, WHERE X IIS THE NUMBER OF HYDROXYL GROUPS IN SAID POLYWHERE X IS THE NUMBER OF HYDROXYL GROUPS IN SAID POLYHYDRIC ALCOHOL, AND THE PROPORTIONS OF POLYHYDRIC ALCOHOL, POLYCARBOXYLIC ACID, UNSATURATED FATTY ACID AND POLYMETHYLOLALKANOIC ACID PROVIDING A RESIN HAVING AN ACID NUMBER BETWEEN ABOUT 35 AND ABOUT 75, SAID POLYMETHYLOLALKANOIC ACID PROVIDING AT LEAST HALF OF SUCH ACID NUMBER.