Abstract: Novel photochromic spiropyran compounds having an absorption sensitivity in a longer wavelength region than known photochromic compounds are provided. The novel spiropyran compounds have a spiropyran skeleton having a methoxy group at the 6 position, a nitro group at the 8 position, a bromine atom at the 5' and 7' positions, and an alkyl group at the 1' position.

Abstract: The present invention provides a photochromic material possessing absorption sensitivity in a longer wavelength region when compared with conventional photochromic materials.

Abstract: An optical storage medium comprising a recording layer containing organic dye molecules which allows recording due to change in the molecular structure or molecular aggregate structure induced by irradiation with light, and a stable controlling layer formed on the recording layer, which controlling layer is stable against the irradiation by the lights for recording or reading out. A multi-frequency optical storage medium comprises a plurality of a combination of the recording layers and the controlling layer as a separating layer.

Abstract: A process for preparing photochromic spiropyran compounds having a halogen atom or atoms and a hydrophobic alkyl group wherein a starting photochromic spiropyran compound having the hydrophobic alkyl group is reacted directly with a halogenating agent in a solvent. This reaction efficiently proceeds with the product being obtained in high yield.

Abstract: The optical storage medium of the present invention comprises: (1) a substrate; (2) ultra-thin recording layers containing a dye; and (3) controlling layers. The recording layers and the controlling layers are accumulated alternately, and the uppermost layer is a controlling layer. The optical storage medium of the present invention contains dye cohesions in the recording layer in an extremely small amount and of extremely small size so that the medium can store a high density of records.

Abstract: A lubricant for recording media having excellent sliding characteristics and abrasion resistance is obtained when an alkylsilane of the following formula (I) is prepared in a thin layer with the LB method: ##STR1## Example of the alkylsilane include .gamma.-(N,N-dioctadecylsuccinylamino)propyltriethoxysilane and .gamma.-[N-[tris-(heptadecylyloxymethyl)] methylsuccinylamino]-propyltriethoxysilane.

Abstract: A long-chain keto group is introduced into the molecule of furylfulgide hng no hydrophobic group to procure a good balance of hydrophilicity and hydrophobicity, thereby making it possible to obtain a uniform ultra-thin film optical recording medium having photochromism of fulgide according to spin coating method or Langmuir-Blodgett method.

Abstract: The invention provides an optical recording medium comprising a Langmuir-dgett film made from a mixture of a photochromic compound of the following formula, in which a carboxyl group and an alkyl group have been introduced to the 8-position and the 1'-position, respectively, at the same time, and a long-chain carboxylic acid: ##STR1## wherein R represents a hydrocarbon having 5 to 31 carbon atoms.

Abstract: An optical recording medium which comprises a substrate and a recording layer of at least two J-aggregates of dyes formed on the substrate is described. The dyes may be photochromic dyes or other types of dyes capable of forming the aggregates which have narrower absorption spectral ranges than original dyes. A plurality of information bits can be written in the recording layer by irradiation of one laser beam spot. The recording layer is formed by an LB film method or a method capable of fluidizing a dye solution in a direction horizontal to the substrate surface. A recording method using the medium is also described.

Abstract: A long-chain keto group is introduced into the molecule of furylfulgide hng no hydrophobic group to procure a good balance of hydrophilicity and hydrophobicity, thereby making it possible to obtain a uniform ultra-thin film optical recording medium having photochromism of fulgide according to spin coating method of Langmuir-Blodgett method.

Abstract: The invention provides a photochromic material characterized by an improvnt in balance of the substituents in the conventional furylfulgides and represented by the general formula: ##STR1## (wherein R represents an alkyl chain having 5 to 31 carbon atoms). According to this molecular structure, a mutually appropriate steric hindrance is induced between the isopropylidence group and the long-chain alkyl group to make the regio isomer unstable, thus preventing the regio isomer from being by-produced while also inhibiting any isomerization reaction from occuring in the synthesis of the fulgide. Further, a good balance of hydrophilic part and hydrophobic part is produced to facilitate formation of a Langmuir-Blodgett film.

Abstract: An optical recording medium is prepared by the use of spiropyrane whose molecular structure contains an alkyl chain having at least 10 more carbon atoms, and by the use of an LB film method or a spin coating method. This recording medium is of a structure wherein when irradiated with the UV, the spiropyrane is photo-isomerized to photomerocyane and, thereafter, when subsequently heated at 35.degree. to 40.degree. C. for 15 minutes, a J-aggregate of the photomerocyane is formed in very stabilized form. When the recording medium is irradiated with light of wavelength of visible spectrum, the color is bleached with the information consequently recorded. The optical recording medium herein disclosed is rewritable and can retain the recorded information for 5,000 hours or more.

Abstract: A optical recording medium which comprises a substrate and a recording layer of at least two J-aggregates of dyes formed on the substrate is described. The dyes may be photochromic dyes or other types of dyes capable of forming the aggregates which have narrower absorption spectral ranges than original dyes. A plurality of information bits can be written in the recording layer by irradiation of one laser beam spot. The recording layer is formed by an LB film method or a method capable of fluidizing a dye solution in a direction horizontal to the substrate surface. A recording method using the medium is also described.

Abstract: An optical recording medium comprising a substrate and an information recording layer which consists of monolayer assemblies comprising a photochromic compound of which is based on cis-trans isomerization such as an amphipathic derivative of azobenzene, indigo or thioindigo having a long chain substituent, which monolayers are formed on the substrate by the Langmuir-Blodgett method and oriented in a two-dimensional plain. When the recording medium is irradiated by light, light absorption spectrum of the recording layer changes so that information is recorded. Since the photochromic compound is oriented in a monolayer, its photochromism lasts long.

Abstract: A composition for absorption refrigeration which comprises a fluorinated hydrocarbon refrigerant, an amide or glycol ether solvent serving as an absorption liquid, and a phosphite stabilizer. The stabilizer is used in an amount of 0.05 to 0.5 wt % of the absorption liquid calculated as phosphorus, within which range the phosphite stabilizer can suitably protect the refrigerant and the absorption liquid from deteriorating and decomposing at high operation temperatures.

Abstract: The present invention relates to an improvement of a solar refrigeration system. The solar refrigeration system has been improved by combining a solar collector-generator and a heat exchanger into one unit to increase the performance efficiency of the system by eliminating heat losses. The solar collector-generator comprises a tube and header arrangement including a plurality of double-walled tubes, each consisting of an outer pipe and an inner pipe, the inner pipe defining a passage for a high temperature refrigerant-lean or weak solution, whereas, the outer and inner tubes defining therebetween a passage for a low temperature refrigerant-rich or strong solution.

Abstract: A system to accomplish both air cooling and air heating of indoor space by utilizing solar energy. In principle the disclosed system is an absorption refrigeration system, wherein a solution of an evaporable refrigerant in a less evaporable solvent is passed through a solar collector-generator, but the system has additional fluid passages with the provision of changeover valves arranged so as to pass the refrigerant in heated and vaporized state from the collector-generator to an indoor heat exchanger, bypassing the condenser of the refrigerator, thereby to accomplish air heating and return the refrigerant in liquid state from the heat exchanger to the collector-generator, bypassing the absorber of the refrigerator.

Abstract: An electrophotographic photosensitive plate having, in order from the bottom up, an electrically conductive substrate, a photosensitizing layer composed of vitreous selenium and tellurium having a thickness of 0.1 to 3 microns, and a top organic layer including polyvinyl carbazole or a derivative thereof, the photosensitizing layer being composed of a first layer of 0.05 to 2 microns in thickness having 60 to 90 weight % of selenium and 40 to 10 weight % of tellurium and a second layer of 0.05 to 1 micron in thickness having a higher concentration of selenium than that of the first layer, and the second layer being positioned between the first layer and the top organic layer. This invention also provides a process of producing a latent electrostatic image on the plate by providing a negative electrostatic charge thereon and exposing the plate to a light image of visible light having a wavelength in the range of 4000 to 8000A.