Ricoh Company, Ltd.

Kabushiki Kaisha Ricoh

Richo Company, Ltd.

Miyoshi Yushi Kabushiki Kaisha

Shoji Maruyama

Keishi Kubo

Masaru Shimada

Kyoji Tsutsui

Hiroshi Goto

Keishi Taniguchi

Eiichi Kawamura

Ichiro Sawamura

Hiroki Kuboyama

Hideaki Ema

Takehito Yamaguchi

Takashi Yano

Hiroshi Tamura

Yoshihiko Hotta

Masafumi Torii

Hiromi Furuya

Tomio Kubota

Hajime Takayama

Kazukiyo Nagai

Fumio Kawamura

Tsutomu Satoh

Kunio Hayakawa

Masafumi Moriya

Yoshikazu Kaneko

Kazuo Hosoda

Hiroaki Matsui

Hiromitsu Kawase

Takao Igawa

Katsushi Sugiyama

Katsuhisa Kamio

Masatake Kawashima

Katue Kojima

Takamichi Enomoto

A method of reversible selective manifestation of different states of a functional element is disclosed. The functional element is composed of at least two compounds and is capable of alternatively assuming (a) a first state in which the two compounds interact to form a regular aggregate structure, or (b) a second state in which the two compounds do not interact, and at least one of the two compounds is in an aggregate or crystallized state. The respective conditions for attaining one of the two states can be reversibly and extremely speedily controlled, for instance, by use of a heat application device.

Method of reversible selective manifestation of different states of functional element

A thermally reversible color forming composition which includes an electron-donating chromophoric compound and an electron-accepting compound, by which formation and deletion of a color image may be carried out by adjusting thermal energy applied to the composition, wherein the electron-accepting compound is a carboxylic acid compound having the following general formula (1):

Thermally reversible color forming composition and thermally reversible

An image formation material for forming images including color images, such as a toner or developer for use in image formation methods such as electrophotography, electrostatic recording, and in an ink jet printing, includes a binder resin, a dye, and a quencher for preventing the deterioration of the dye; and a method of preventing the fading of images formed by the above image formation methods can be carried out by use of this image formation material.

Image formation materials and image fading prevention method

A reversible thermosensitive coloring composition is composed of an electron-donor coloring compound; an electron-acceptor compound which is capable of producing a colored material with a regularly aggregated structure in the electron-doner coloring compound at a color development initiation temperature to obtain a color development state, and is capable of crystallizing out of the colored material at a decolorization initiation temperature which is lower than the color development initiation temperature; and an organic compound serving as a decolorization-accelerating agent capable of inducing the destruction of the regularly aggregated structure of the colored material to accelerate the decolorization of the composition. A reversible thermosensitive coloring recording medium is composed of a support and a recording layer formed thereon, which contains the above-mentioned reversible thermosensitive coloring composition.

Reversible thermosensitive coloring composition, and recording medium

A rewritable bar code display medium is disclosed, which is composed of a support and a reversible thermosensitive recording layer for reversibly forming bar codes therein formed on the support, which reversible thermosensitive recording layer varies in transparency with change in temperature, and an image display method using the rewritable bar code display medium, and an apparatus for implementing the image display method are also disclosed.

Rewritable bar code display medium, and image display method and image

A reversible thermosensitive coloring composition is composed of (i) an electron-donor coloring compound and (ii) an electron-acceptor compound selected from the group consisting of an organic phosphoric acid compound, an aliphatic carboxylic acid, and a phenolic compound, each having a straight chain or branched chain alkyl group or alkyenyl group having 12 or more carbon atoms, the electron-donor coloring compound and the electron-acceptor compound being capable of reacting to induce color formation in the reversible thermosensitive coloring composition at the eutectic temperature thereof. The electron-donor coloring compound and the electron-acceptor compound, when fused and colored in a mixed state, with application of heat thereto, followed by rapidly cooling the fused mixture, exhibit an exothermic peak in a temperature elevation process in a differential scanning calorific analysis or in a differential thermal analysis. A recording medium and display medium using the above reversible thermosensitive coloring composition, a recording method of using the recording medium, a display method of using the display medium, a display method of using the display medium, and a display apparatus using the display medium are disclosed.

Reversible thermosensitive coloring composition, recording medium,

A reversible thermosensitive recording material is composed of a reversible thermosensitive recording layer capable of reversibly assuming a transparent state and a white opaque state depending on the temperature thereof, in which recording layer an organic low-molecular-weight material is dispersed in a matrix resin, the organic low-molecular-weight material being composed of a eutectic mixture containing as the main component a saturated higher fatty acid with 23 to 32 carbon atoms and a higher fatty acid.

Reversible thermosensitive recording material

A thermosensitive recording material composed of a support, and a thermosensitive recording layer formed on the support, containing a leuco dye, a color developer capable of inducing color formation in the leuco dye upon application of heat thereto, and a thermofusible material including p'-methylphenyl p-chlorobenzoate serving as a thermosensitivity-improving agent.

Thermosensitive recording material

A reversible thermosensitive coloring composition is composed of (i) an electron-donor coloring compound and (ii) an electron-acceptor compound selected from the group consisting of an organic phosphoric acid compound, an aliphatic carboxylic acid, and a phenolic compound, each having a straight chain or branched chain alkyl group or alkenyl group having 12 or more carbon atoms, the electron-donor coloring compound and the electron-acceptor compound being capable of reacting to induce color formation in the reversible thermosensitive coloring composition at the eutectic temperature thereof. The electron-donor coloring compound and the electron-acceptor compound, when fused and colored in a mixed state, with application of heat thereto, followed by rapidly cooling the fused mixture, exhibit an exothermic peak in a temperature elevation process in a differential scanning calorific anlaysis or in a differential thermal analysis. A recording medium and display medium using the above reversible thermosensitive coloring composition, a recording method of using the recording medium, a display method of using the display medium, a display method of using the display medium, and a display apparatus using the display medium are disclosed.

Reversible thermosensitive coloring recording medium, recording method,

A dithiolate metal complex compound having formula [I] ##STR1## wherein each R individually represents an alkyl group having 1 to 6 carbon atoms, a halogen, a halogenated alkyl group having 1 to 6 carbon atoms, an amino group which may be substituted with 1 or 2 alkyl groups each having independently 1 to 4 carbon atoms, or a trifluoromethyl group, M represents a transition metal selected from the group consisting of Ni, Pd, Pt, Co, Cu and Mn, n is an integer of 0 to 4, and A represents the counter cation of the complex compound, a method of producing the same, and an optical information recording medium comprising a recording layer comprising a polymethine dye and the dithiolate metal complex compound are disclosed.

Dithiolate metal complex compound, production method of the same, and

The present invention relates to a photosensitive material for use in electrophotography comprising a photoconductive layer on which there is a transparent protective layer consisting essentially of a substance resulting from partial hydrolysis of a mixture of (a) a compound having the following general formula I, (b) a copolymer of a compound having the general formula II with a compound having the general formula III or maleic anhydride and (c) a compound having the general formula IV,

Photosensitive material for use in electrophotography

Photoconductive, film forming nitropyrene-formaldehyde resins characterized by a repeating structural unit of the formula: ##SPC1## And process for preparation, the photoconductive films themselves, and such films on an electrically conductive support.

Process for manufacturing nitropyrene-formaldehyde resin

There are provided sensitizers for electrophotographic light-sensitive materials including organic photoconductors and electrophotographic light-sensitive materials containing same. The sensitizers are reaction products comprising benzopyrylium salt and benzopyran.

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Yokohama, Japan

Shoji Maruyama