| 摘要 |
<p>Disclosed are novel compounds of the formula:
<Chemistry id="chema01" num="0001"><Image id="ia01" he="29" wi="66" file="IMGA0001.TIF" imgContent="chem" imgFormat="TIFF" /></Chemistry> wherein:
X=-NR₅R₆, or -OR₇;</p><p>R₁ and R₂ are independently hydrogen, substituted or unsubstituted alkyl, haloalkyl, hydroxyalkyl, alkoxyalkyl, alkylaminoalkyl or arylalkyl having up to 18 carbons; cycloalkyl; phenyl or naphthyl; alkylphenyl, cyanophenyl, halophenyl or alkoxyphenyl substituents.</p><p>R₃ is hydrogen, benzyl, alkoxybenzyl, halobenzyl or alkylbenzyl, provided that if neither R₁ nor R₂ is hydrogen, then R₃ is hydrogen.</p><p>R₄ is a divalent aromatic group which is substituted or unsubstituted.</p><p>R₅, R₆, and R₇ are independently hydrogen, alkyl, hydroxyalkyl, haloalkyl, alkoxyalkyl, alkylaminoalkyl, acylaminoalkyl, aminoalkyl or phenylalkyl having up to 12 carbons; a cycloalkyl substituent; phenyl or naphthyl; an alkylphenyl, cyanophenyl, halophenyl or alkoxyphenyl substituent.</p><p>Furthermore, either R₁ and R₃ or R₁ and R₂ can be linked to form a heterocyclic ring system containing 3-10 atoms.</p><p>Additionally, R₅ and R₆ can be linked to form a heterocyclic ring system containing 3-10 atoms.</p><p>Y is an oxygen or sulfur atom. If Y is sulfur then n=1, if Y is oxygen then n=0 or 1. <!-- EPO <DP n="2"> --></p><p>These compounds are useful as high-quality dot promoting agents in negative-working photographic systems.</p><p>Disclosed as well are radiation-sensitive compositions and elements containing such dot promoting agents in combination with silver halide grains. These exposed compositions and elements when processed in a developer containing a dihydroxybenzene developing agent, a substituted benzotriazole, a sulfite preservative and an amine compound provide a method for the production of halftone dots possessing high image quality. </p> |
