Microporous typewriter ribbons

Claim 1

A PRESSURE-SENSITVE, INK-TRANSFER PRODUCT SUITABLE FOR USE IN TYPEWRITER AND HIGH-SPEED PRINER RIBBONS, TAPES AND SHEETS COMPRISING (A) A SHOCK-ABSORBENT BASE LAYER OF AN ELASTOMERIC POLYMER FILM HAVING A HIGH DEGREE OF RESILIENCY IN A DIRECTION NORMAL TO THE PLANE OF SUCH FILM; (B) AN INTERMEDIATE LAYER OF A THIN, NON-ELASTIC POLYMER FILM BONDED TO THE SHOCK-ABSORBENT BASE LAYER; AND (C) AN INKING LAYER BONDED TO THE INTERMEDIATE LAYER OF NON-ELASTIC POLYMER IFLM OVER SUBSTANTIALLY ITS ENTIRE WORKING SURFACE AND COMPRISING A SUBSTANTIALLY CONTINUOUS FILM OF A MICROPOROUS INKING COMPOSITION CONSISTING ESSENTIALLY OF A UNIFORMLY BLENDED MIXTURE OF (I) AND ELASTOMERIC POLYMERIC BINDER, (II) AN INKING COMPOUND COMPRISING A NON-AQUEOUS, NON-VOLTATILE INK CARRER WHICH IS SUBSTANTIALLY INSOLUBLE IN THE LEASTOMERIC POLYMERIC BINDER AND WHICH CONTAINS A HIGH CONCENTRATION OF AN INK PIGMENT, AND (III) A FINELY GROUND MICROPOROUS INORGANIC FILLER.