Abstract: There is disclosed an optical information record medium having an optical information record layer on a transparent substrate, in which the transparent substrate is made of a resin material mainly consisting of a polycarbonate resin that contains no more than 4 wt % of low molecular weight fractions having a weight average measured with respect to a polystyrene molecular weight of no more than 3500, in order to avoid a double refraction of an optical information record medium resulting in an improved signal to noise ratio and having superior thermal-transformation resistance and impact resistance.

Abstract: A wavelength multiplexed optical recording material is disclosed wherein a photosensitive material including substituted porphine, such as tetra(pentafluorophenyl) porphine or tetra(4-methoxyphenyl) porphine, is uniformly dispersed into an optically transparent dispersion medium. When such wavelength multiplexed optical recording material is cooled to a temperature of liquid helium and irradiated with a laser beam, a large number of holes of narrow width are formed in an inhomogenous absorption band under the phenomenon of photochemical hole burning. As compared to unsubstituted porphine, the above porphine derivatives give an improved recording sensitivity and narrow hole width.

Abstract: The present application describes a photoresist material which contains organo-silicon groups and the photoresist material is suitable for forming a micropattern applied in the fabrication of semiconductor integrated circuit and magnetic bubble memory elements. The photoresist material possesses high resistance to plasma etching using oxygen gas.

Abstract: A laser information recording medium comprising a substrate, a reflective layer and a recording layer. The recording layer is made of cumulative sub-layers of J-aggregates of an organic dye having an absorption band in the wavelength range of oscillation of the laser and an anionic film-forming material. The cumulative sub-layers may be formed by the Langmuir-Blodgett thin film method. The recording layer may also consist of a plurality of layers containing organic dyes having different absorption peaks of wavelength in their respective sub-layers. The organic dyes are preferably cyanine dyes of a specific type and the cationic film-forming material is preferably a mixture of at least two members of the group consisting of dioctadecyldimethylammonium chloride, octadecylamine and methyl stearate.

Abstract: An optical recording medium including a substrate and a photosensitive layer thereon, the photosensitive layer containing as its major ingredients, the combination of a polymeric binder resin and an indolinospirobenzothiopyran compound represented by the general formula (I): ##STR1## where R.sub.1, R.sub.2 and R.sub.3 are each a hydrogen atom, a halogen atom, an alkyl group containing from 1 to 5 carbon atoms, an alkoxy group containing from 1 to 5 carbon atoms, an alkoxymethyl group containing from 1 to 5 carbon atoms in the alkoxy group, a hydroxymethyl group or an alkylaminomethyl group containing 2 to 6 carbon atoms in the alkyl group. The optical recording medium has a colored image which is very stable against heat and visible light.

Abstract: A photochromic photosensitive composition comprising a indolinobenzothipyran-based spiropyran compound, a transparent, high molecular weight film forming resin, and a compound represented by the general formula (I): ##STR1## wherein R.sub.1, R.sub.3, R.sub.4 and R.sub.6 each represents a hydrogen atom, a halogen atom or a hydroxyl group, R.sub.2 and R.sub.5 each represents a hydrogen atom or a hydroxyl group, and X represents --NH--, --S--, ##STR2## (where R.sub.7 and R.sub.8 each represents a hydrogen atom, --CH.sub.3, --C.sub.2 H.sub.5, --CH.sub.2 CH.sub.

Abstract: Novel photochromic compounds are disclosed, which compounds are represented by the general formula ##STR1## in which R.sub.1 represents an alkyl group having 1 to 20 carbon atoms, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 independently represent an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogen atom, a nitro group, a cyano group or a dimethylamino group, and R.sub.6, R.sub.7 and R.sub.8 independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen atom, and correspondingly 97 to 50 wt % of a film-forming polymer. Photosensitive compositions and materials comprising the compounds are also described.

Abstract: A method for forming a color image includes a step of spraying three kinds of photoconductive toners with a sensitization wavelength band different from its absorption wavelength band, a step of electrically charging these different toners, a step of exposing these sprayed and electrically charged photoconductive toners to light for selectively removing electrostatic charges, and a step of removing the toners freed of electrostatic charges from the substrate. The magenta color photoconductive toners sensitive to red light, yellow color photoconductive toners sensitive to green light, and the cyan color photoconductive toners sensitive to blue light, are used as aforementioned three kinds of photoconductive colors.

Abstract: A photochromic photosensitive composition contains a benzothiazolinospiropyran compound represented by the general formula: ##STR1## wherein R.sub.1 represents an alkyl group containing 1 to 10 carbon atoms, R.sub.2 represents an alkyl group containing 1 to 10 carbon atoms or a phenyl group, R.sub.3 represents a hydrogen atom, a halogen atom, a methoxy group or an alkyl group containing 1 to 5 carbon atoms, and R.sub.4 represents a hydrogen atom, an alkyl group containing 1 to 5 carbon atoms, a methoxy group or a methylthio group, dissolved or dispersed in a bisphenol A type polyether resin for enhancing thermal stability of the compound in a colored state. Addition of a phenol to the composition serves to further enhance the heat stability. As compared with conventional photochromic compositions, this photochromic photosensitive composition is thermally extremely stable in a colored state, and the developed color image can be stored for an enough long time to be suited for long-time recording.

Abstract: A magnetic recording medium is disclosed in which dispersion characteristics of magnetizable particles in a magnetic paint is improved which results in improved saturation magnetic flux density and squareness ratio. The dispersion characteristics is improved by the treatment of magnetizable particle with a titanium alcoholate compound having at least one group easy to be hydrolyzed and at least one oleophilic group hard to be hydrolyzed in an organic solvent.

Abstract: A magnetic recording medium is produced using a highly purified lecithin which is selectively adsorbed upon magnetic powder particles so as to coat substantially the entire surface of such particles with a monomolecular layer, thereby providing a magnetic record medium of improved magnetic properties.