| 摘要 |
<p>A thermal transfer printing sheet, suitable for use in a thermal transfer printing process, especially for the conversion of a digital image into a visible print, comprising a substrate having a coating comprising a dye of the formula: <CHEM> wherein Ring A is unsubstituted or carries, in the 2- or 4-position with respect to the azo link, at least one group selected from -CX3, X<1>, CN, NO2, -OCO.Y, -CO.Y, -CO.H, -OSO2.Y and -SO2.Y, provided that A is substituted when Z is CH3 and R is C2-4-alkyl; X and X<1> are each independently halogen; Y is selected from R<1>, -OR<1>, SR<1> and -NR<1>R<2>; R<1> is selected from C1-12-alkyl, C1-12-alkyl interrupted by one or two groups selected from -O-, -CO-, O.CO- and -CO.O-, C3-7-cycloalkyl, mono- or bi-cyclic aryl and C1-3-alkylene attached to an adjacent carbon atom on Ring A; R<2> is selected from H, C1-12-alkyl, C3-7-cycloalkyl and mono- or bi-cyclic aryl; Z is C1-12-alkyl or phenyl; and R is selected from C2-12-alkyl unbranched in the alpha-position, C2-12-alkyl unbranched in alpha-position and interrupted by one or two groups selected from -O-,-CO-, O.CO- and -CO.O-, phenyl, C1-4-alkylphenyl, biphenyl and biphenyl interrupted by a group selected from -O-, -CO-, O.CO- and -CO.O-, each of which is free from hydrogen atoms capable of intermolecular hydrogen beonding.</p> |
