Process for low temperature preparation of aqueous solution of polyalkylene amine-polyamide resins

Claim 1

IN A PROCESS OF PREPARING AN AQUEOUS SOLUTION OF CATIONIC THERMOSETTING RESIN BY (A) FORMING A LONG-CHAIN WATER-SOLUBLE POLYAMIDE FROM A DIESTER OF A C3 TO C6 SATURATED ALIPHATIC DICARBOXYLIC ACID WITH A C1 TO C3 SATURATED ALIPHATIC ALIPHATIC AND A POLYALKYLENE POLYAMINE HAVING TWO PRIMARY AMINE GROUPS AND AT LEAST ONE SECONDARY AMINE GROUP THE MOL RATIO OF SAID POLYAMINE TO SAID DIESTER BEING FROM ABOUT 0.8/1 TO 1.4 1, AND (B) THEN REACTING SAID POLYAMIDE IN AQUEOUS SOLUTION WITH EPICHLOROHYDRIN IN AMOUNT SUCH THAT THE MOL RATIO OF EPICHLOROHYDRIN TO THE SUM OF SECONDARY AND TERTIARY AMINE GROUPS IN THE POLYAMIDE IS FROM ABOUT 0.5LI TO ABOUT 1.8/1, THE IMPROVEMENT WHICH COMPRISES FORMING THE POLYAMIDE BY REACTING THE POLYALKYLENE POLYAMINE UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS AT FROM ABOUT 80* TO ABOUT 95*C., FROM ABOUT 1.5 TO 3 HOURS, AT ATMOSPHERIC PRESSURE WITH THE DIESTER AND REMOVING THE ALCOHOL FORMED AT A TEMPERATURE NO HIGHER THAN ABOUT 105*C. TO PRODUCE A POLYAMIDE HAVING AN INTRINSIC VISCOSITY OF FROM ABOUT 0.08 TO 0.12 DL/GRAM IN 1 N AQUEOUS AMMONIUM CHLORIDE AT 25*C.