Microcapsules for pressure-sensitive materials - produced from emulsion of an active liquid contg. droplet-enveloping cpds.

摘要

Microcapsules est. suitable for a pressure-sensitive copying paper, contg. an active liquid (esp. a coloured liquid or liquid producing colouration when contacted with another substance), are produced by emulsifying the active liquid in an aq. soln. of a macromolecular cpd(s), pref. a 1:1 mixt. of gelatine and gum arabic; adding a stabiliser (pref. CMC or another cellulose deriv.) to promote the formation of macromolecule envelopes around droplets of the active liquid; and effecting gelling of the envelopes by cooling the emulsion. Microcapsules of uniform size are produced; their strength prevents incidental smearing, and yet the pressure-sensitivity is sufficient for typing, handwriting, etc. Apart from recording materials, other substances can be micro-encapsulated by this method, e.g. adhesives, drugs, fertilizers, foodstuffs, cosmetics etc.