Birch, Stewart, Kolasch & Birch, LLP
Asymmetrical trimethine cyanine dyes for high capacity optical recording medium
 An optical recording layer of an optical recording medium comprises a dye material represented by the formula (I), ##STR1## wherein PA1 R.sub.1 is a hydrogen atom, a methyl group, or an ethyl group, PA1 R.sub.2 and R.sub.3 each is, independent from each other, a substituted or unsubstituted C1 to C12 alkyl group, PA1 A.sup..crclbar. is an anion selected from the group consisting of halogen atoms, ClO.sub.4.sup..crclbar., BF.sub.4.sup..crclbar., PF.sub.6.sup..crclbar., SbF.sub.6.sup..crclbar., CF.sub.3 SO.sub.2.sup..crclbar., C.sub.2 F.sub.5 SO.sub.3.sup..crclbar., CF.sub.3 COO.sup..crclbar., and CH.sub.3 C.sub.6 H.sub.4 SO.sub.3.sup..crclbar., PA1 X is hydrogen, alkyl, alkoxy, halogen, nitro, or fused benzene, PA1 Y is hydrogen, alkoxy, halogen, alkyl, aryl, alkoxycarbonyl, aryloxycarbonyl, alkylamine, arylamine, alkylamide, arylamide, alkylsulfonyl, aryl sulfonyl, alkoxysulfonyl, aryloxysulfonyl, nitro, or cyano groups. 
Ritek Corporation
Y C G Y G G Y G
Y10T C09B G11B Y10S G11B G11B Y10S G11B
additional inventional additional additional additional additional additional inventional
Shyh-yeu Chwei-jin Mei-jung Hui-jen Chang-sheng Yi-shiu
Wang Yeh Hu Chen Huang Lin