| 摘要 |
<p>1420175 Microcapsules BADISCHE ANILIN- & SODA-FABRIK AG 21 March 1973 [22 March 1972] 13483/73 Heading B8C [Also in Division D2] Microcapsules useful in carbonless copying comprise a shell and a core comprising a dye or colour-former and a water-immiscible liquid consisting essentially of a mono- or poly-alkylated benzene containing at least 5 carbon atoms in the alkyl group(s). Other solvents may also be included, e.g. high boiling aliphatic hydrocarbons, diphenyl benzenes, terphenyls, phthalic esters, indans, tetralin, polynuclear aromatics and alkylated polynuclear aromatics. The microcapsules may be made by any convenient process, e.g. conservation, inter-facial polymerization or spray-drying techniques. The capsule walls may similarly be of any suitable material, that preferred being a copolymer formed by solution polymerization of methyl methacrylate and an acetylacetate of a monoacrylate or monomethacrylate of an aliphatic diol of 2 to 8 C atoms and, optionally, acrylamide, acrylic or methacrylic acid, vinylpyrrolidone, vinylsulphonic acid and 2-sulphoethyl methacrylate. The microcapsules may be coated on to suitable substrates in the usual way to produce record transfer sheets. Reference has been directed by the Comptroller to Specification 1,368,707.</p> |
