Sheet forming binder particles composed of thermoplastic polymer dispersed in a polysaccharide matrix

Claim 1

A PULP OF SHEET-FORMING BINDER PARTICLES OF A PRECIPITATED POLYSACCHARIDE, THE SAID POLYSACCHARIDE BEING SELECTED FROM THE GROUP CONSISTING OF CELLULOSE, ALGINATE, SOLUBLE STARCH, AND GALACTOMANNAN GUMS AND HAVING A DEGREE OF POLYMERIZATION OF AT LEAST ABOUT 10, AND THE SAID PARTICLES CONTAINING FROM ABOUT 75% TO ABOUT 95% BY WEIGHT OF A DISPERSED PHASE OF PARTICULATE SYNTHETIC THERMOPLASTIC POLYMER HAVING A PARTICLE SIZE RANGING FROM COLLOIDAL UP TO ABOUT PARTICLES PASSING A NUMBER 80MESH SCREEN BUT RETAINED ON A NUMBER 100-MESH SCREEN AND THE SAID PARTICLES OF SAID PULP HAVING A HIGH SURFACE AREA AND POSSESSING (A) AN ABILITY TO FORM A WATERLEAF HAVING A COUCHED WET TENACTY OF AT LEAST ABOUT 0.034 LB./IN./OZ./SQ. YD. WHEN AN AQUEOUS DISPERSION OF THE SAID PULP IS DEPOSITED FROM A LIQUID SUSPENSION UPON A FORAMINOUS SURFACE, WHICH WATERLEAF, WHEN DRIED AT A TEMPERATURE BELOW ABOUT 50*C., HAS A DRY TENACITY AT LEAST EQUAL TO ITS COUCHED WET TENACITY AND (B) AN ABILITY, WHEN A PLURALITY OF THE SAID BINDER PARTICLES IS DEPOSITED CONCOMITANTLY WITH STAPLE FIBERS FROM A LIQUID SUSPENSION UPON A FORAMINOUS SURFACE, TO BOND THE SAID FIBERS BY PHYSICAL ENTWINEMENT OF THE SAID BINDER PARTICLES WITH THE SAID FIBERS TO GIVE A COMPOSITE WATERLEAF WITH A WET TENACITY OF AT LEAST ABOUT 0.034 LB./IN./SQ. YD.