Method of producing a thermoplastic adhesive and product thereof

Claim 1

IN A METHOD OF PRODUCING A THERMOPLASTIC ADHESIVE FILM CHARACTERIZED BY NONTACKINESS AT ROOM TEMPERATURE AND BY THE PROPERTY OF BECOMING TACKY UPON HEATING THEREOF TO A PREDETERMINED TEMPERATURE HIGHER THAN ROOM TEMPERATURE AND REMAINING TACKY FOR A SUBSTANTIAL TIME INTERVAL FOLLOWING SUBSEQUENT COOLING TO SUBSTANTIALLY ROOM TEMPERATURE AND WHICH COMPRISES AS THE ESSENTIAL CONSTITUENTS THEREOF A MAJOR PROPORTION OF A THERMOPLASTIC RESIN AND A SPECIFIC THERMOPLASTIC BOTH HAVING SOFTENING POINTS HIGHER THAN ROOM TEMPERATURE AND AT LEAST ONE OF SAID SOFTENING POINTS BEING LOWER THAN THE BOILING POINT OF WATER, THE STEPS OF FORMING A HOT MELT COMPRISING AT LEAST SAID ONE OF SAID ESSENTIAL CONSTITUENTS OF SAID COMPOSITION HAVING SAID SOFTENING POINT LOWER THAN THE BOILING POINT OF WATER, ADDING TO SAID MELT AN AQUEOUS DISPERSION OF A RUBBERY MATERIAL NOT READILY SOLUBLE OR OTHERWISE INCORPORABLE FROM A DRY STATE IN SAID MELT, HEATING SAID MELT TO A TEMPERATURE SUFFICIENT TO BOIL AWAY THE AQUEOUS CARRIER FROM SAID DISPERSION WHILE MIXING SAID MELT TO EFFECT THROUGH DISPERSION THEREIN OF SAID RUBBERY MATERIAL IRRESPECTIVE OF THE DEGREE OF COMPATIBILITY OF SAID RUBBERY MATERIAL IN SAID MELT, ADDING TO SAID MELT ANY OF SAID ESSENTIAL CONSTITUENTYS THEREOF NOT ALREADY PRESENT THEREIN WHILE MAINTAINING THE TEMPERATURE OF THE MELT ABOVE THE SOFTENING POINTS OF ALL CONSTITUENTYS THEREOF, APPLYING SAID MELT AS A FILM ON A SUPPORTING SURFACE, COOLING SAID FILM TO A TEMPERATURE BELOW SAID SOFTENING POINT OF SAID PLASTICIZER, AND THEN SETTING THE RESULTING COOLED BUT STILL TACKY FILM TO NONTACKY CONSISTENCY BY APPLYING THERETO A SMALL QUANTITY OF THE SAME SAID SPECIFIC PLASTICIZER IN