OLIGOMERIC POLYESTERS WITH A NARROW INTERVAL OF MOLECULAR MASSES, AND PROCESS FOR THEIR PREPARATION.

摘要

P THE POLYESTER COMPOSITION ACCORDING TO THE INVENTION AT A MEDIUM MOLECULAR MASS GREATER THAN 500 AND COMPRISES A PREDOMINANT COMPOUND WHOSE MAJOR POLYESTER CHAIN HAS AT LEAST 17 TO LESS THAN 52 CARBON ATOMS AND AT LEAST 6 TO LESS THAN 18 D ATOMES OXYGEN, AT LEAST 52 BY WEIGHT OF THE MOLECULES HAVING A MOLECULAR MASS LESS THAN 50 OF THE AVERAGE MOLECULAR MASS OF THE COMPOSITION, WHICH IF POSSIBLE CONTAINS BY MOLE AT LEAST 1.6 EQUIVALENTS OF HYDROXY OR CARBOXY INTACT GROUPS, WITH BY MOLE AT LEAST 4 EQUIVALENTS OF ESTER LINKS IN THE MAIN CHAINS. / P P THIS COMPOSITION IS PREPARED THROUGH A SERIES OF ALTERNATIVE REACTIONS AT THEIR TERM, THE FINAL MOLECULE OF EACH REACTION CREATING THE ONLY SITE OF REACTION AVAILABLE FOR THE FOLLOWING REACTION ON THE OTHER MONOMER. ANHYDRIDE IS REACTED ON A HYDROXYL TO OBTAIN AN ESTER AND A CARBOXYL GROUP AND AN OXIRAN ON A CARBOXYL TO OBTAIN AN ESTER AND A HYDROXYL GROUP. THE SEQUENCE OF ALTERNATIVE REACTIONS BEGINS BY A POLYOL (REACTION ON AN ANHYDRIDE) OR A POLYCARBOXYLIC ACID (REACTION ON AN OXIRAN). / P P THE INVENTION FINDS ITS MAIN APPLICATION IN THE MANUFACTURE OF PAINTS. / P