Oil-resistant adhesive tape

Claim 1

PERMANENTLY PRESSURE-SENSITIVE OIL-RESISTANT ADHESIVE TAPE OR SHEET MATERIAL COMPRISING A THIN FLEXIBLE BACKING MEMBER CARRYING A SURFACE LAYER OF OIL-RESISTANT NORMALLY TACKY AND PRESSURE-SENSITIVE ADHESIVE COMPRISING: (A) A RUBBERY POLYMER OF MONOMERS INCLUDING ABOUT 10-40 PERCENT OF ACRYLONITRILE AND CORRESPONDINGLY ABOUT 90-60 PERCENT OF OTHER COPOLYMERIZABLE MONOMER OF WHICH AT LEAST A MAJOR PROPORTION IS BUTADIENE AND NOT MORE THAN A MINOR PROPORTION IS STYRENE, SAID POLYMER HAVING A HIGH FREQUENCY MODULUS OF ABOUT 20-50 MEGADYNES PER SQ. CM. AND A CONSTANT STRESS MODULUS OF ABOUT 0.66-2.5 MEGADYNES PER SQ. CM. AS HEREIN DEFINED; (B) SUFFICIENT PLASTICIZER, COMPATIBLE WITH THE POLYMER AT ROOM TEMPERATURE, AND WITHIN THE RANGE OF ABOUT 0-50% BASED ON THE WEIGHT OF SAID POLYMER, TO PROVIDE WHEN CONBINED WITH SAID POLYMER A RUBBERY BASE MATERIAL HAVING A HIGH FREQUENCY MODULUS OF ABOUT 15-40 MEGADYNES PER SQ. CM. AND A CONSTANT STRESS MODULUS OF ABOUT 0.3-1.8 MEGADYNES PER. SQ. CM.; AND (C) A MINOR BUT SUBSTANTIAL PROPORTION, BASED ON THE TOTAL WEIGHT OF THE ADHESIVE, OF A THERMOPLASTIC TACKIFIER RESIN WHICH IS SUBSTANTIALLY INSOLUBLE IN HEPTANE AND IS COMPATIBLE WITH SAID RUBBERY BASE MATERIAL.