Process for producing polyamide coating materials

Abstract

Abstract IN THE PRESENT INVENTION, I PREPARE POLYAMIDE PREPOLYMERS FROM AROMATIC DIANHYDRIDE AND AROMATIC DIAMINE MATERIALS BY FIRST PRODUCING A STABLE NONIONIC PRECURSOR MATERIAL IN THE FORM OF THE REASON PRODUCT OF AN AROMATIC DIANHYDRIDE AND AROMATIC DIAMINE IN THE MOLAR RATIO OF 2/1. THERE IS THEN ADDED TO THIS STABLE PRECURSOR WHICH MAY BE REPRESENTED BY THE FORMULA XYX, WHEREIN X REPRESENTS AROMATIC DIANHYDRIDE AND Y REPRESENTS AROMATIC DIAMINE, A SLIGHT MOLAR EXCESS OF Y AND IN SO DOING, I DO NOT FOLLOW EXPECTED PATH OF POLYMERIZATION WHICH HAD BEEN PREDICTED. INSTEAD, THE XYX TENDS TO POLYMERIZE ONLY UP TO A CERTAIN POINT AND THEN I COMPLETE THE POLYMERIZATION TO ANY DESIRABLE MOLECULAR WEIGHT RANGE BY SLOWLY ADDING A PREDETERMINED ADDITIONAL AMOUNT OF DIANHYDRIDE X AS A BACK ADDITION. IN THIS MANNER, THE PATH OF REACTION FOLLOWED BY INHERENT VISCOSITY WHICH IS AN INDICATOR OF MOLECULAR WEIGHT, THEN CLIMBS SHARPLY AND BY MEANS OF SLOWLY ADDING THE ANHYDRIDE I CAN CLOSELY CONTROL THE MOLECULAR WEIGHT, SUBSTANTIALLY INCREASING SUCH MOLECULAR WEIGHT AND NARROWING THE RANGE OF MOLECULAR WEIGHT OF THE POLYORTHOAMIC ACID PREPOLYIMIDE MATERIAL. I CAN THEREBY THROUGH THIS PROCEDURE OBTAIN ANY PRESELECTED DESIRABLE MOLECULAR WEIGHT RANGE BY THE BACK ADDITION OF DIANHYDRIDE TO AMINE TERMINATED POLYAMIDE PREPOLYMERS.

Inventors

• 👤 Marvin A Peterson

Bibliographic Details