| 摘要 |
A photothermographic color construction is disclosed, the construction having at least two color-forming layers comprising: a. a first, spectrally-sensitized, color-forming layer coated out of a solvent system selected from lower alkyl alcohols (up to 4 carbon atoms) ketones (up to 6 carbon atoms), aromatic hydrocarbons (up to 10 carbon atoms), or mixtures thereof, b. an upper, second, different, spectrally-sensitized color-forming layer coated out of a toluene or acetone solvent system, and c. a barrier layer comprising a polymer and a color developer coated between said first and second color-forming layers, said polymer being impervious to toluene or acetone, said polymer being an admixture of a first polymer, polyvinylpyrrolidone (PVP), and a second polymer which is (i) a neutralized and (ii) a hydrolyzed or lower alkyl-esterfied form of a poly(methyl vinyl ether/maleic anhydride) copolymer, in the range of 30 weight percent PVP/70 weight percent neutralized second polymer to 75 weight percent PVP/25 weight percent neutralized second polymer (the weight percentages being of the solventless admixture) said barrier layer is impervious to the solvent system of an overlaying color-forming layer; and further wherein each color-forming layer is sensitized to a portion of the spectrum at least 60 nm different from the other color-forming layer, and each color-forming layer contains a leuco dye (colorless) which when oxidized forms a dye (colored) having a maximum absorbance at least 60 nm different from that of the dye (colored) formed in the other color-forming layer.
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