Polyamide-epoxy adhesive

Claim 1

AN ADHESIVE ADAPTED FOR USE IN LAMINATING, COMPRISING THE THERMOSET REACTION PRODUCT OF ABOUT FROM 1.5 TO 10.5% BY WEIGHT OF AN EPOXY RESIN AND ABOUT 98.5 TO 89.5% BY WEIGHT OF A POLYAMIDE RESIN, SAID REACTION PRODUCT RESULTING FROM THE MIXING OF SAID EPOXY RESIN AND SAID POLYAMIDE RESIN IN A LIQUID STATE AT A TEMPERATURE OF FROM 200 TO 300*C., SAID EPOXY RESIN BEING OF THE CLASS CONSISTING OF COMPLEX POLYMERIC EPOXY-HYDROXY ETHERS RESULTING FROM THE CATALYZED REACTION OF A POLYHYDRIC ALCOHOL WITH AN EXCESS OF EPOXIDE, AND CONSISTING ESSENTIALLY OF A RESINOUS GLYCERYL POLYETHER OF A MEMBER OF THE GROUP CONSISTING OF POLYHYDRIC PHENOLS AND POLYHYDRIC ALCOHOLS, THE EPOXY RESIN HAVING AN EPOXIDE EQUIVALENT WEIGHT OF ABOUT 140 TO 525, AND AN AVERAGE MOLECULAR WEIGHT OF ABOUT FROM 275 TO 1,000, SAID POLYAMIDE RESIN HAVING A SUBSTANTIALLY STABLE MELTING POINT WHEN HELD IN A MOLTEN STATE AND COMPRISING A HOMOGENEOUS BLEND OF FROM 60 TO 75% BY WEIGHT OF POLYAMIDE RESIN A AND FROM 40 TO 25% BY WEIGHT OF POLYAMIDE RESIN B, SAID RESIN A BEING THE REACTION PRODUCT OF A POLYMERIC FAT ACID AND A POLYALKYLENE POLYAMINE, THE POLYALKYLENE POLYAMINE BEING EMPLOYED IN A RATIO OF 1.3 TO 3.0 EQUIVALENTS OF AMINE PER EQUIVALENT OF CARBOXYLIC ACID, SAID RESIN A HAVING BEEN SUBJECTED TO A BODYING TREATMENT AT 200* TO 300*C. OF SUFFICIENT DURATION TO BRING THE GARDNER-HOLDT VISCOSITY TO WITHIN THE RANGE C TO F, SAID RESIN B BEING THE REACTION PROCDUCT OF AN ALKYLENE DIAMINE AND A MIXTURE OF A POLYMERIC FAT ACID AND A POLYCARBOXYLIC ACID SELECTED FROM THE GROUP CONSISTING OF ALIPHATIC AND AROMATIC POLYCARBOXYLIC ACIDS IN WHICH THE CARBOXYL GROUPS ARE SEPARATED BY FROM 3 TO 8 CARBON ATOMS, THE BLEND OF RESIN A AND RESIN B HAVING BEEN EFFECTED AT A TEMPERATURE WITHIN THE APPROXIMATE RANGE OF 200 TO 220*C. FOR A TIME SUFFICIENT TO EFFECT AN AMIDE INTERCHANGE BETWEEN THE RESINS.