Kanzaki Paper Manufacturing Co., Ltd.

Gensuke Matoba

Makoto Miyake

Shunsuke Shioi

Shunshuke Shioi

A process for producing a powder of microcapsules characterized by adding an aldehyde resin precondensate to a microcapsule dispersion prepared in water or a hydrophilic medium with use of a water-soluble high molecular compound as an emulsifier, maintaining the resulting mixture in a condition for promoting polycondensation of the precondensate, and removing the dispersing medium from the reaction mixture, and a process for producing a powder of microcapsules characterized by emulsifying a hydrophobic core material containing a specific oil-soluble melamine-formaldehyde resin precondensate in water or a hydrophilic medium, subjecting the emulsion to a condition for promoting polycondensation to form capsule wall films and obtain a microcapsule dispersion, and thereafter removing the dispersing medium from the dispersion are disclosed. Further, processes for producing a non-aqueous microcapsule composition are also disclosed.

Process for producing powder of microcapsules

In a recording material producing images due to a complex formed from an organic phosphorus-iron compound having a bond of PO.sup.- and/or PS.sup.- with Fe.sup.3+ in the molecule and a ligand compound which reacts with the organic phosphorus-iron compound, the present recording material is characterized in that (a) a colorless or light-colored oil-soluble and/or heat-fusible organic compound adheres to the surface of the organic phosphorus-iron compound and/or (b) an organic base is present out of contact with the organic phosphorus-iron compound. The present invention also provides a desensitizer comprising at least one compound selected from the group consisting of (a) organic phosphorus compounds having a bond of P--OH and/or P--SH, (b) organic compounds having an aminocarboxyl group and (c) salts of these compounds (a) and (b).

Recording materials

In a microencapsulation process which causes hydrophobic core material containing an oil-soluble melamine-formaldehyde precondensate to emulsified in water or in a hydrophilic medium, and to form capsule wall film under conditions for promoting polycondensation, the process which is characterized in that said oil-soluble melamine-formaldehyde precondensate is 40 to 100% in a degree of formaldehyde substitution, 80 to 100% in alkylation degree, and 4 to 11 in hydrophobic degree.

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Osaka, Japan

Gensuke Matoba