Ricoh Company, Ltd.

Kunihiko Hada

Yasutomo Mori

Shuji Miyamoto

Motoo Tasaka

Motoi Orihara

Mitsuru Naruse

Yoshikazu Kaneko

Kazuyuki Uetake

Takeshi Kajikawa

Yasuhiro Kadota

Michiyo Fukushima

The present invention provides a heat-sensitive recording material having a support, a heat-sensitive color-developing layer containing a leuco dye and a developer, and a protective layer, the heat-sensitive color-developing layer and the protective layer being formed on the support, wherein carboxylic-acid-modified polyvinyl alcohol with a weight average degree of polymerization of 100 to 400 and a modification degree of 0.2 mol % to 1.0 mol % is used as a dispersing agent for dispersing the leuco dye.

Heat-sensitive recording material

A heat-sensitive recording material comprising on one surface of a substrate a heat-sensitive coloring layer comprising a leuco dye and a color developer, wherein the heat-sensitive recording material comprises a layer which comprises a copolymer of a (meth)acryloyloxyalkylammonium salt and styrene; and the layer which comprises the copolymer of the (meth)acryloyloxyalkylammonium salt and styrene is at least any one of a back layer, an under layer and a protective layer.

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 thermal printing material having a substrate and a recording layer on the substrate, the recording layer containing a leuco compound color and a developer for developing the leuco compound color when heated, the developer comprising a compound represented by the formula: ##STR1## wherein each of R1 through R8 indicates a hydrogen atom or an alkyl group having from 1-5 carbon atoms, and n indicates an integer from 6-14.

Thermal printing material for providing improved image reliabilities

A thermosensitive recording material composed of a support, a thermosensitive recording layer formed on the support, capable of producing colored images by heating, and a protective layer formed on the thermosensitive recording layer, which contains as a resin component a copolymer resin obtained by copolymerization of arylamide or methacrylamide, acrylonitrile, and a vinyl monomer having a carboxyl group, or a copolymer resin of a core-shell emulsion type obtained by copolymerization of acrylamide and/or methacrylamide in the presence of a seed emulsion of an acryl-based copolymer or methacryl-based copolymer, and as a crosslinking agent a compound having two or more alkyleneimino groups, a carbodiimide compound, a methyl ethyl ketoxime compound, or bis(.beta.-hydroxyethyl)sulfone.

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Numazu, Japan

Kunihiko Hada