Abstract: The object is to provide a novel nonsolvate-form crystal of polymethine compound which has good stability in solution, shows a high gram extinction coefficient, is excellent in storage stability, is easy to handle and is highly sensitive to general-purpose semiconductor lasers. Thus are provided a nonsolvate-form crystal of a polymethine compound of the formula (I) and a process for producing the nonsolvate-form crystal of polymethine compound of formula (I) which comprises reacting a polymethine ether compound of the formula (II) given below with p-toluenesulfonic acid. (In the above formula, TsO represents the p-toluenesulfonic acid residue.) (In the above formula, R represents an alkyl group, an alkoxyalkyl group or an optionally substituted aryl group.

Abstract: The invention relates to novel phthalocyanine compounds, their intermediates and a process for their preparation. The inventive phthalocyanine compound absorbs in the near infrared region of the spectrum with a high absorption coefficient which features high solubility in solvents, good compatibility with resins and high aging resistance, thus finding application as a near infrared ray absorbing material or a light-heat conversion material with great advantage and to a process for producing the phthalocyanine compound. The novel phthalocyanine compound has the following general formula: ##STR1## wherein R represents alkyl or alkoxyalkyl; X represents halogen, alkylthio, phenylthio which may be substituted, or naphthylthio which may be substituted; M represents a couple of hydrogen atoms, a divalent metal, or a trivalent or tetravalent metal derivative. The near infrared ray absorbing and light-heat conversion materials containing the above phthalocyanine compound are also described.

Abstract: The invention relates to a novel phthalocyanine compound absorbing in the near infrared region of the spectrum with a high absorption coefficient which features high solubility in solvents, good compatibility with resins and high aging resistance, thus finding application as a near infrared ray absorbing material or a light-heat conversion material with great advantage and to a process for producing the phthalocyanine compound. The novel phthalocyanine compound has the following general formula: ##STR1## wherein R represents alkyl or alkoxyalkyl; X represents halogen, alkylthio, phenylthio which may be substituted, or naphthylthio which may be substituted; M represents a couple of hydrogen atoms, a divalent metal, or a trivalent or tetravalent metal derivative. The near infrared ray absorbing and light-heat conversion materials containing the above phthalocyanine compound are also described.

Abstract: Naphthalocyanine compounds represented by the general formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4, which may be the same or different, are each a straight chain or branched chain alkyl group of 5 to 12 carbon atoms and M is a metal selected from the group consisting of Cu, Ni, Mg, Pb, Pd, V, Co, Nb, Al, Sn, In, Fe and Ge, or its oxide, chloride or bromide, are bluish green or green crystals and are superior in absorption of near infrared rays of 750 to 850 nm, highly resistant to light, heat, acids and alkalis, soluble in organic acids, liquid crystals and resins, and accordingly are very useful as a dyestuff capable of absorbing near infrared rays.

Abstract: Naphthalocyanine compounds represented by the general formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4, which may be the same or different, are each a straight chain or branched chain alkyl group of 5 to 12 carbon atoms and M is a metal selected from the group consisting of Cu, Ni, Mg, Pb, Pd, V, Co, .[.Nb,.]. Al, Sn, In, Fe and Ge, or its oxide, chloride or bromide, are bluish green or green crystals and are superior in absorption or near infrared rays of 750 and 850 nm, highly resistant to light, heat, acids and alkalis, soluble in organic acids, liquid crystals and resins, and accordingly are very useful as a dyestuff capable of absorbing near infrared rays.