| 摘要 |
1477411 Coating sheet materials WIGGINS TEAPE Ltd 15 Aug 1975 [23 Aug 1974] 37124/74 Heading B2E Sheet material such as paper and board is coated with a composition comprising particulate solid material suspended in a liquid carrier, by foaming the composition to a foamed state in which it is of lower viscosity than in the unfoamed state, applying the foam to the sheet and drying it. The coatings are art paper coating compositions and colour developer sheets for pressure sensitive copying systems, e.g. acidic clay and phenolic resin systems. The foaming operation consists of entraining air into the composition by rapid mixing or stirring after addition of a foaming agent which is a surface active material, e.g. lauryl ethylene oxide, alkyl phenyl ethers, alkyl phenyl ethylene oxides, alkyl ether sulphates, alkyl benzene sulphonates, alkyl sulphates, and polyvinyl alcohol. Other ingredients of the compositions are china clay, acidic clay, calcium carbonate, binders such as vinyl and acrylic resins, sodium silicate, talc, phenolic resins, starch, carboxymethylcellulose, styrene butadine resin latex, and carboxylated styrene-butadiene resin. The foam is coated onto the substrate sheet by a blade coater. |
