摘要 |
<p>1,254,252. Capsule-containing coating. NATIONAL CASH REGISTER CO. 23 April, 1970 [5 May, 1969], No. 19473/70. Heading. B2E. [Also in Division B6] Minute polymer-walled capsules containing a liquid are applied to a substrate of e.g. paper or plastics material by dispersing them in a liquid, which softens the capsule walls, the dispersion onto the substrate and hardening the capsule walls. The encapsulated liquid may be a pentane, or may contain solid particles in a dispersion. Preferably the capsule walls are of gelatin, gum arabic, currageonan, zein, guar gum, polyethylene oxide, polyvinyl pyrolidone, ethyl cellulose, polyvinyl alcohol, a polyethylene glycol, polyethylene, polyethylene imine or a partially or completely hydrolyzed copolymer or ethylene maleic anhydride. The capsules may be dispersed in an aqueous vehicle, which contains a binder such as polyvinyl alcohol, starch, polyacrylic acid, gum arabic or carboxymethyl cellulose,, or in an organic liquid containing ethyl cellulose, cellulose acetate, polyvinyl acetate, shellac or a natural gum. Clays, colloidal silica, sodium carboxymethyl cellulose, pigments, dyes, wetting agents and antifoam agents may be included.</p> |