Pressure-sensitive adhesive compositions for tape and methods for dispensing same

Claim 1

THE METHOD OF FORMING PRESSURE-SENSITIVE ADHESIVE COATED SHEET MATERIAL WHICH INCLUDES THE STEPS OF PROVIDING A BODY OF HEAT STABLE, SUBSTANTIALLY SOLVENT FREE, PRESSURE-SENSITIVE ADHESIVE COMPRISING A MIXTURE OF THERMOPLASTIC RESINS CONSISTING ESSENTIALLY OF AT LEAST ONE POLYVINYL ALKYL ETHER IN WHICH THE ALKYL GROUP HAS FROM 2 TO 4 CARBON ATOMS AND A LOW MOLECULAR WEIGHT STYRENE POLYMER COMPOSED OF AT LEAST ONE STYRENE FROM THE GROUP CONSISTING OF STYRENE AND STYRENE HOMOLOGUES, SAID MIXTURE COMPRISING FROM ABOUT 20% TO ABOUT 70% BY WEIGHT OF A HIGH MOLECULAR WEIGHT POLYVINYL ALKYL ETHER AND AT LEAST ABOUT 10% BY WEIGHT OF SAID LOW MOLECULAR WEIGHT POLYMER OF A STYRENE, HEATING SAID BODY OF ADHESIVE TO BRING IT TO FLUID MOLTEN CONDITION, FLOWING MOLTEN ADHESIVE FROM SAID BODY BY GRAVITY IN A COLUMN INCLUDING A TERMINAL UPWARDLY DIRECTED COLUMN PORTION ENDING AT A LEVEL BELOW THE LEVEL OF THE SURFACE OF ADHESIVE IN SAID BODY OF MOLTEN ADHESIVE, DISPOSING A BACKING SHEET ACROSS AND WITH ITS UNDER SIDE IN CONTACT WITH THE END OF SAID COLUMN OF MOLTEN ADHESIVE TO RESTRAIN FLOW OF SAID COLUMN, MOVING SAID BACKING SHEET ACROSS THE END OF SAID COLUMN TO COAT SUCCESSIVE PORTIONS OF THE UNDER SIDE OF SAID BACKING WITH SAID MIXTURE, AND THEN COOLING SAID SUCCESSIVE PORTIONS OF SAID BACKING WITH THE COATING OUT OF CONTACT WITH OTHER SURFACES TO SOLIDIFY SAID MIXTURE TO A STRONGLY COHESIVE PRESSURE-SENSITIVE ADHESIVE LAYER ON SAID BACKING.

Claim 2

THE METHOD OF FORMING PRESSURE-SENSITIVE ADHESIVE COATED SHEET MATERIAL WHICH INCLUDES THE STEPS OF PROVIDING A BODY OF HEAT STABLE, SUBSTANTIALLY SOLVENT FREE, PRESSURE-SENSITIVE ADHESIVE COMPRISING A MIXTURE OF THERMOPLASTIC RESINS CONSISTING ESSENTIALLY OF AT LEAST ONE POLYVINYL ALKYL ETHER IN WHICH THE ALKYL GROUP HAS FROM 2 TO 4 CARBON ATOMS AND A LOW MOLECULAR WEIGHT STYRENE POLYMER COMPOSED OF AT LEAST ONE STYRENE FROM THE GROUP CONSISTING OF STYRENE AND STYRENE HOMOLOGUES, SAID MIXTURE COMPRISING FROM ABOUT 20% TO ABOUT 70% BY WEIGHT OF A HIGH MOLECULAR WEIGHT POLYVINYL ALKYL ETHER AND AT LEAST ABOUT 10% BY WEIGHT OF SAID LOW MOLECULAR WEIGHT POLYMER OF A STYRENE, HEATING SAID BODY OF ADHESIVE TO BRING IT TO FLUID MOLTEN CONDITION, FLOWING MOLTEN ADHESIVE FROM SAID BODY BY GRAVITY IN A COLUMN INCLUDING A TERMINAL UPWARDLY DIRECTED COLUMN PORTION ENDING AT A LEVEL BELOW THE LEVEL OF THE SURFACE OF ADHESIVE IN SAID BODY OF MOLTEN ADHESIVE, DISPOSING A BACKING SHEET ACROSS AND WITH ITS UNDER SIDE IN CONTACT WITH THE END OF SAID COLUMN OF MOLTEN ADHESIVE TO RESTRAIN FLOW OF SAID COLUMN, MOVING SAID BACKING SHEET ACROSS THE END OF SAID COLUMN TO COAT SUCCESSIVE PORTIONS OF THE UNDER SIDE OF SAID BACKING WITH SAID MIXTURE, AND THEN COOLING SAID SUCCESSIVE PORTIONS OF SAID BACKING WITH THE COATING OUT OF CONTACT WITH OTHER SURFACES TO SOLIDIFY SAID MIXTURE TO A STRONGLY COHESIVE PRESSURE-SENSITIVE ADHESIVE LAYER ON SAID BACKING.