Patent ID: 7402375
Filing Date: 2008-07-22
Classification: C09B,G11B,Y10S

Abstract:
1. A light absorbent composition applied to an optical recording medium substrate having a track pitch of below 0.74 microns comprising (a) a monomethine cyanine dye of Formula 1 which has an absorption maximum at a wavelength of 450 nm or less when in a thin layer form; and (b) organic dye compounds other than said monomethine cyanine dye, said organic dye compounds being sensitive to a laser beam with a wavelength of 775 to 795 nm: wherein in Formula 1, ø1 is a heterocyclic group represented by Formula 5 and ø2 is a heterocyclic group represented by any one of Formulae 2, 3, 4, 6, 7 and 8 as resonance structures; wherein throughout Formulae 2 to 5, Z represents an optionally substituting mono- or polycyclic aromatic ring or heterocycle which condenses to a nitrogen atom-containing five-membered heterocycle; throughout Formulae 2 to 8, R and (i) optionally at least one formazan metal complex.