| 摘要 |
1381928 Record sheet MOORE BUSINESS FORMS Inc 16 March 1972 [17 March 1971] 12341/72 Heading D2B A record sheet for forming a colored image on imagewise contact with an electron-donating colorless dye precursor in the absence of a secondary dye precursor of low developing speed comprises a support, e.g. paper, carrying clay particles, at least 20% by wt. of which is smectite clay characterised by an expanding three layer lattice molecular structure which, when analysed in the presence of the benzyl ether of Michler's hydrol by X-ray diffraction with nickel filtered copper radiation of 1.54Š. wavelength, shows at least a discernible peak at a 2# value of 5.6-5.7 # being the Bragg angle, asufficient proportion of said structure having been irreversibly chemically modified to impart substantially Newtonian viscosity behaviour to an aqueous suspension containing at least 14% by weight of the clay particles. The smectile clay may be chemically modified by acid treatment, followed by substantial removal of the acid and acid salts from the clay. The smectite clay particles may be used together with non-smectite clay particles. The record sheet may be used with a transfer sheet coated with microcapsules containing the dye precursor, or it may itself be coated with such micracapsules. The microcapsules may be contained in an ink exudable from a non-transferable porous plastics layer on a transfer sheet. |
