Ricoh Company, Ltd.

Motoi Orihara

Masami Tomita

Hachiro Tosaka

Tomoe Hagiwara

Shinichi Kuramoto

Norihiko Inaba

Yasutomo Mori

Shuji Miyamoto

Kunihiko Hada

Koji Suzuki

Satoru Inoue

Toshiki Nanya

Yasuo Asahina

Kimitoshi Yamaguchi

Hiroyuki Fushimi

Naoki Iwata

Shigekazu Enoki

Yasuo Hirano

Kazuo Nojima

Kazumi Ohtaki

Yoshiaki Matsunaga

Shunichi Chiba

Tomohisa Kakuda

Kohichi Katoh

Yoshihiro Nomura

Noriaki Ide

Eiji Fukui

Hiroshi Tanaka

Provided is a thermosensitive recording material which can be produced through high-speed coating, which is excellent in head-matching property, and which can provide a printed image having good waterproofness, while maintaining high sensitivity and high storage stability, which material includes a support, an under layer laid over the support, the under layer containing a plastic hollow particle, a thermosensitive color-developing layer laid over the under layer, the thermosensitive color-developing layer containing a leuco dye and a developer, wherein two or more layers including the thermosensitive color-developing layer are formed through simultaneous coating by a curtain coating method.

Thermosensitive recording material

To provide a heat-sensitive recording material including a substrate; a heat-sensitive color-developing layer over the substrate, the heat-sensitive color-developing layer containing a leuco dye and a developer; a first protective layer over the heat-sensitive color-developing layer, the first protective layer containing a water-soluble resin and a crosslinking agent; and a second protective layer over the first protective layer, the second protective layer containing a water-soluble resin, a crosslinking agent and a pigment, wherein the heat-sensitive color-developing layer, the first protective layer and the second protective layer are formed simultaneously by curtain coating method, and the second protective layer contains diacetone-modified polyvinyl alcohol and acrylic resin or maleic acid copolymer resin.

Heat-sensitive recording material

A thermosensitive recording medium is disclosed which includes a support, and a thermosensitive color-developing layer formed on the support and containing a leuco dye having a melting point of at least 200.degree. C. and a color developer having a melting point of at least 180.degree..

Thermosensitive recording medium

A thermosensitive recording material having a high degree of background whiteness, superior light resistance without coloring of the background when exposed to the light, and a method of producing a stable coating liquid or forming a thermosensitive coloring layer and a protective layer are provided.

Thermosensitive recording material and production process thereof

A toner comprising a binder resin and a coloring agent, with an aggregation degree of 5 to 60%, and an absolute value of Q/M measured by the suction method of 2 to 30 .mu.C/g for use in (1) an image formation method in which electric charges are selectively held on the surface of a development roller to form a number of closed micro fields near the surface of the development roller, a non-magnetic one-component type developer comprising toner, with addition of an auxiliary agent thereto when necessary, is supplied onto the development roller, the developer is held on the surface of the development roller by the micro fields, and latent electrostatic images are developed to visible toner images, and (2) an image formation method in which the surface of a developer-bearing member having a chargeable and photoconductive surface is charged, the charged surface is selectively exposed to light for form a number of micro fields near the developer-bearing member, a non-magnetic one-component type developer comprising toner, to which auxiliary agents may be added when necessary, is supplied onto the development roller, the developer is held on the surface of the development roller by the micro fields, and latent electrostatic images are developed to visible images by the developer.

Toner and method of developing

An image formation method of developing a latent electrostatic image formed on a latent-electrostatic-image bearing member to a visible toner image by a one-component type developer consisting essentially of a toner is carried out by the steps of forming numerous micro closed electric fields near the surface of a developer-bearing member by causing the developer-bearing member to selectively hold electric charges on the surface thereof; supplying the developer to the surface of the developer-bearing member to hold the toner on the surface of the developer-bearing member by the micro closed electric fields; and developing a latent electrostatic image to a visible toner image by the toner. The toner is composed of a binder resin, a coloring agent and a quaternary ammonium salt serving as a charge controlling agent.

Image formation method

In a developing device and a dry color toner for color electrophotography. The developing device is provided with a toner conveying member and a toner layer thickness controlling member which is in contact with the toner conveying member. The color toner for developing electrostatic images used in this developing device has the following relation between the number average particle diameter and the volume average particle diameter: ##EQU1## Even after a continuous copying, the developing device and the color toner provide substantially the same image quality as that in the earlier stages of the continuous copying.

Developing device of the type forming thin layer of toner on toner

This invention relates to a developing apparatus for one component type toner, which has a thin film-forming element applying a thin film of one component type toner on the surface of a toner holder, characterized in that said thin film-forming element is composed of a silicone rubber comprising 100 parts by weight of a siloxane polymer having a cross linking density of 4-8.times.10.sup.-4 mol/cc and 30-70 parts by weight of silica.

Developing apparatus

This invention relates to a toner for developing an electrostatic latent image, which contains a coloring agent, a binder resin and a charge controlling agent as the main components, said charge controlling agent being a metal salt of salicylic acid or derivatives.

Toner for developing electrostatic latent image

A developer comprises a mixture of (a) magnetic toner particles comprising a polymeric material and finely-divided magnetic particles, having an electric resistivity of 10.sup.12 .OMEGA.cm or more, and (b) electroconductive magnetic particles having an electric resistivity of 10.sup.9 .OMEGA.cm or less, a smaller volume mean diameter than that of the magnetic toner particles, with the saturation magnetic moment of the electroconductive magnetic particles being in the range of from 25 emu/g to 75 emu/g, which is larger than the saturation magnetic moment of the magnetic toner particles.

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Numazu, Japan

Motoi Orihara