Abstract: Phthalonitrile, an alkali metal or an alkali metal compound, and a hydrogen donor compound are heated in an organic solvent to synthesize a partially hydrogenated alkali metal phthalocyanine, which is then brought into contact with a dealkalizing agent to effect substitution with hydrogen of the partially hydrogenated alkali metal phthalocyanine to thereby obtain high-purity metal-free phthalocyanine. FX-type metal-free phthalocyanine as obtained according to the foregoing procedure may be used as a charge-generating substance to produce an electrophotographic photoconductor of high image quality which is highly sensitive to near infrared rays.

Abstract: An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer including a charge generation material and a charge transport material. The charge generation material is a titanyloxyphthalocyanine crystal having a maximum diffraction intensity observed at Bragg angle (2.theta.) of 9.6.degree..+-.0.2.degree. and clear peaks of diffraction intensity observed at 7.22.degree..+-.0.2.degree., 9.60.degree..+-.0.2.degree., 11.60.degree..+-.0.2.degree., 13.40.degree..+-.0.2.degree., 14.88.degree..+-.0.2.degree., 18.34.degree..+-.0.2.degree., 23.62.degree..+-.0.2.degree., 24.14.degree..+-.0.2.degree., and 27.32.degree..+-.0.2.degree., respectively, in a X-ray diffraction spectrum obtained by performing a X-ray diffraction method using CuK.alpha. as a source of radiation, and having a lattice constant of:a=16.3058 .ANG., b=23.078 .ANG., and c=8.7115 .ANG.,.alpha.=101.352.degree., .beta.=23.078.degree., and .gamma.=117.530.degree. ,with an allowable error of .+-.1%.

Abstract: A magnetic recording medium and a method for the manufacture thereof are disclosed that are less likely to result in head crushing even if high-hardness slider materials are used, and which is formed with a carbon protective layer that has good anti-CSS characteristics. The carbon protective layer is formed using a sputtering gas mixed with methane at a greater amount than predetermined to form a carbon protective layer in which diamond bonds are present at a higher ratio than graphite bonds, and polymeric bonds are present to an adequate degree. A magnetic recording medium having such a carbon protective layer shows a very high durability in a CSS cycle test.

Abstract: An electrophotographic photoconductor, includes metal-free phthalocyanine as a charge-generating substance, wherein the X-ray diffraction spectrum of said metal-free phthalocyanine as measured using CuK.alpha. as a radiation source includes intense diffraction peaks at Bragg angles (2.theta..+-.0.2.degree.) of 7.5.degree., 9.0.degree., 16.6.degree., 17.2.degree., 21.5.degree., 22.2.degree., 23.8.degree., and 28.5.degree., and wherein the infrared absorption spectrum of said metal-free phthalocyanine includes four absorption bands with the maximum absorption intensity at a wavenumber of 716 cm.sup.-1 between a wavenumber of 700 cm.sup.-1 and a wavenumber of 760 cm.sup.-1 and a characteristic absorption band at a wavenumber of 3,291.+-.2 cm.sup.-1.

Abstract: Phthalonitrile, an alkali metal or an alkali metal compound, and a hydrogen donor compound are heated in an organic solvent to synthesize a partially hydrogenated alkali metal phthalocyanine, which is then brought into contact with a dealkalizing agent to effect substitution with hydrogen of the partially hydrogenated alkali metal phthalocyanine to thereby obtain high-purity metal-free phthalocyanine. FX-type metal-free phthalocyanine as obtained according to the foregoing procedure may be used as a charge-generating substance to produce an electrophotographic photoconductor of high image quality which is highly sensitive to near infrared rays.

Abstract: The quality of a lubricant layer formed on a surface of a magnetic recording medium is determined by exposing the lubricant molecules of the lubricant layer to a radiation source for x-ray photoelectron spectroscopy while varying the photoelectron drawing angle. The number of emitted electrons is determined and, from this, the degree of orientation and the quality of the lubricant layer is found.