The Mead Corporation

Ncr Corporation

Frederick D Weaver

Bruce W Brockett

Gary D Pack

A process is disclosed for the manufacture of microcapsules which comprises the steps of preparing hydrophobic and hydrophilic phase components. The hydrophobic phase component comprises a homogeneous solution of an electron donating chromogenic material and a hydrophobic material. The hydrophilic phase component comprises a mixture of a regulating agent and water, the regulating agent being a starch material. The hydrophobic phase component is combined with a hydrophilic phase component to form an oil-in-water emulsion. The oil-in-water emulsion further contains aqueous solutions of urea, resorcinol and formaldehyde. The pH of the oil-in-water emulsion is adjusted to a level at which the capsule wall forming reaction is initiated by the addition of a catalyst. The temperature of the partially reacted oil-in-water emulsion is then elevated to from about 50.degree. C. to about 80.degree. C. and this temperature is maintained for a period of time sufficient to form discrete microcapsules characterized by being substantially impermeable to the hydrophobic emulsion component.

Encapsulation process

Record material is disclosed comprising paper sheet material coated with droplets of liquid wherein the liquid comprises 2,2,4-trimethyl-1,3-pentanediol diisobutyrate. Said liquid is associated on the record material with at least two color-producing reactants, at least one of which is soluble in said liquid. The liquid is associated with the reactants by either being in close proximity to both reactants or by having one of the reactants dissolved therein and being in close proximity to the other. Of the color-producing reactants, one is a chromogenic dye-precursor and one is a coreactant material capable of developing the color of the chromogenic dye-precursor when the two reactants are brought into reactive contact.

Pressure-sensitive record material

Metal-modified para-substituted phenol-aldehyde novolak resins suitable for use in pressure sensitive manifolding systems are produced by melting and mixing together a para-substituted phenol-aldehyde resin and a metal alkanoate salt in the presence of an ammonium compound.

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Chillicothe, OH, United States of America

Frederick D Weaver