| 摘要 |
A composition used for making pressure-sensitive transfer sheets (see Division D2) comprises (Example 1) carnauba wax, raw mortar wax, beeswax, lanolin, mineral oil, magnetic iron oxide and aluminium powder. Specifications 621,957, 947,771, 1,000,986 and 1,007,278 are referred to. Reference has been directed by the Comptroller to Specification 683,505.ALSO:Compositions used for making pressure-sensitive transfer sheets (see Division D2) comprise: (Example 2) ethylcellulose, mineral oil, lanolin, magnetic iron oxide, titanium dioxide and toluene, and (Example 3) chlorinated polyphenyl resin, beeswax, carbon tetrachloride, magnetic iron oxide and titanium dioxide. Specifications 621,957, 947,771, 1,000,986 and 1,007,278 also referred to. Reference has been directed by the Comptroller to Specification 683,505.ALSO:A transfer sheet comprises a flexible foundation and a pressure-transferable surface coating which is applied in a single coating operation and is adapted to be transferred in image form substantially en bloc to a copy sheet. The transfer coating comprises a binder and two pigments of different densities and colours, the two pigments being concentrated in different strata so that the overlying stratum masks the colour of the underlying stratum. The transfer coating may be applied as a uniform mixture of binder and pigments, and the binder kept in a liquid state while differential migration, due to the difference of density, of the two pigments takes place, and then solidified. If one of the pigments is magnetic, the differential migration may be assisted by passing the sheet over a magnet. The transfer-coating may be applied to parts only of the foundation, and the exposed stratum may have substantially the same colour as the foundation. The uncoated side may be a printed form. The binder may be a wax, a mixture of a wax with lanolin or mineral oil or both, ethylcellulose, which may be mixed with mineral oil and lanolin, a polymer or copolymer of vinyl chloride or vinyl acetate, polyvinyl butyrate, polystyrene, a chlorinated polyphenyl resin or a resin-modified alkyd resin. Pigments referred to are: magnetic iron oxide, iron filings or powder, titanium dioxide, zinc oxide, aluminium oxide, calcium oxide, calcium carbonate, graphite, carbon black, powdered aluminium, silver, bronze, zinc, nickel and tin, crystal violet, methyl violet, magenta, rhodamine, saframine, nigrosine, Bismarck brown, chrome yellow and methyl orange. The foundation sheet may be of paper, polyethylene terephthalate, regenerated cellulose, cellulose acetate or polyvinyl acetate. Specifications 621,597, 947,771, 1,000,986 and 1,007,278 are also referred to. Reference has been directed by the Comptroller to Specification 683,505.
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