Process for producing polyamide coating materials by endcapping

Abstract

Abstract I FIRST PREPARE A POLYAMIDE PREPOLYMER USING AROMATIC DIANHYDRIDE AND AROMATIC DIAMINE STARTING MATERIALS WHEREIN THE REACTANTS ARE IN THE MOLAR RATIO OF 2/1 AND THEREBY PRODUCE A STABLE PRECURSOR MATERIAL. THERE IS ADDED TO THIS STABLE PRECURSOR, WHICH MAY BE REPRESENTED BY THE FORMULA XYX, OR YXY, WHEREIN X REPRESENTS AROMATIC DIANHYDRIDE AND Y REPRESENTS AROMATIC DIAMINE, A FURTHER AMOUNT OF X OR Y IN A PREDETERMINED MOLAR EXCESS TO EFFECT POLYMERIZATION OF THE PRECURSORS WHICH ARE "ZIPPED UP" TO ANY DESIRABLE MOLECULAR WEIGHT RANGE AND THEREAFTER I SLOWLY ADD EITHER X OR Y (DEPENDING UPON WHICH REACTANT WAS USED TO ZIP UP THE PRECURSOR) AS A BACK ADDITION. IT IS NOTED THAT THE INHERENT VISCOSITY WHICH IS AN INDICATOR OF MOLECULAR WEIGHT CLIMBS SHARPLY, AND IF THE X OR Y IS SLOWLY ADDED TO THE PRECURSOR, THE FORMULATOR CAN CLOSELY CONTROL THE MOLECULAR WEIGHT OF THE POLYORTHOAMIC ACID PREPOLYIMIDE MATERIAL. APPLYING THE DESCRIBED PROCEDURE IT HAS BEEN FOUND THAT AROMATIC CARBOXYLIC DIANYDRIDE TERMINATED MOLECULES EXHIBIT CERTAIN UNDESIRABLE PROPERTIES WHEN THE PREPOLYIMIDE MATERIALS PRODUCED ARE USED AS A COATING ON MAGNET WIRE; AND THEREFORE, FOLLOWING THE DESCRIBED SYNTHESIS PROCEDURE, AND SUBSEQUENTLY TO THE BACK-TITRATION, I PROCEED TO ENDCAP THE MOLECULES BY THE ADDITION OF Y SO THAT ALL OF THE MOLECULES ARE TERMINATED BY Y OR ITS EQUIVALENT WHEREBY THE UNTOWARD EFFECT OF X TERMINATED MOLECULES WILL NOT MANIFEST UNDESIRABLE REACTIONS WHEN THE MATERIALS IS USED IN PRODUCING COATINGS FOR MAGNET WIRE.

Inventors

• 👤 Marvin A Peterson

Bibliographic Details