| 摘要 |
1508378 Thermographic materials MITSUBISHI PAPER MILLS Ltd 16 May 1975 [17 May 1974 18 May 1974] 21036/75 Heading G2C A heat-sensitive material which comprises a support and a layer of (i) a compound of Formula: wherein R 1 to R 5 are H, C 1-18 alkyl, cycloalkyl, aryl, aralkyl, substituted aryl, amino, alkylamino, acylamino, carboylamino, amidino, cyano or heterocyclic, R 6 is C 1-6 alkylene, phenylene, naphthylene or wherein X is C 1-6 alkylene, SO 2 , S 2 , -S-, -O-, -NH- or a single bond, R 7 to R 9 are H, C 1-18 alkyl, cycloalkyl, aralkyl, heterocyclic or alkyl substituted by a primary, secondary or tertiary amino group or at least two of R 7 , R 8 and R 9 complete a heterocyclic ring and (ii) a xanthene or triphenylmethane lactone or sultone which contains an acyloxy or sulphonyloxy group and which is sparingly water-soluble, compounds (i) and (ii) reacting on heating to form a colour. There may be a second colour-forming composition of a phenolic substance and a basic colour former, e.g. crystal violet lactone, in the same or adjacent layer so that 2 images of different colours can be formed at different temperatures. Alternatively, a guanidine may be applied to a first layer on the support and a second layer may contain its colour forming leuco dye as well as the second colour-forming composition (cf Examples 6 and 7). Another variant is to apply one colour-forming composition in the first layer and two colourforming compositions in the second layer so that a greater range of coloured images may be obtained (cf Examples 8 and 9). Comparisons using sodium carbonate instead of the specified bases (i) and fluorescein, phenolphthalein and phenol red instead of the specified leuco dyes (ii) are given.
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