Nippon Paper Industries Co., Ltd.

Nippon Paper Industries, Ltd.

Hideki Hayasaka

Toshimi Satake

Toshiyuki Takano

Tomoaki Nagai

Yukiko Uehori

Akio Sekine

Toshiaki Minami

Kaoru Hamada

Shisei Goto

Hideki Fujiwara

Toru Nakatani

Tetsuro Takahashi

Osamu Kozuka

Katsuhiko Matsunaga

Harutaka Watanabe

Eisaku Katori

A transfer roll coating color is described comprising a pigment and an adhesive as main components, wherein the average aspect ratio of the pigment is 10 or less, the adhesive is a low viscosity starch adhesive, the solids content of the color is about 58 weight % or higher, and the viscosity of the color determined at 60 rpm by using a No. 4 rotor of a Brookfield.TM. viscometer is 1,500 cps or less. Coated papers obtained by transfer roll coating using the colors at an amount of 5 g/m2 or higher per side also are disclosed.

Transfer roll coating color and a coated paper

A near-infrared absorbent is obtained by heating a dimerized thiourea derivative of Formula �1! or �2! and a copper compound: ##STR1## The near-infrared absorbent is used to obtain a near-infrared absorbent resin material having a wide absorption in the near-infrared region, and the absorbent does not substantially decompose at a molding temperature of the resin. Typical examples of the dimerized thiourea derivative are 4,4'-di(benzylthiocarbamoyl)-aminodiphenylmethane, 4,4'-di(benzylthiocarbamoyl)-aminodiphenylhexafluoropropane, and 1,4'-di(dibenzoylthiocarbamoylamino)-2,5-dimethylbenzene, and typical examples of the copper compound are copper stearate and copper .beta.-acryloyloxypropylhydrogenphthalate.

Dimerized thiourea derivatives near-infared absorbents comprising the

An optical recording medium including a substrate having thereon a recording layer containing a dye precursor, a color developer reactable with the dye precursor to develop a color, and a light absorbent for converting light to heat, characterized in that the color developer is at least one compound of Formula (1):

Optical recording medium

In a thermal recording material having a thermal recording layer containing a colorless or pale colored dye precursor and a color developer reactable with the dye precursor upon heating to develop a color of the dye precursor, the color developer is a bisurea compound, for example, Compound A-2. The thermal recording material is superior in stability of background color.

Thermal recording material

In an optical recording sheet having a thermal recording layer containing a colorless or pale colored dye precursor and a color developer reactable with the dye precursor upon heating to develop a color, a dimerized or trimerized urea compound is used as the color developer to obtain an optical recording sheet which is superior in ground color stability and an optical recording sheet having a reversible recordability.

Optical recording sheet

It is provided with a thermal recording material having a support coated with a coating solution as a color developing layer. The color developing layer has a colorless dye precursor which is normally colorless or light-colored, and a developer which reacts with the dye precursor to cause color development thereof upon heating. The developer is a bisthiourea compound represented by, for example, a formula (A-2): ##STR1## and the thermal color developing layer contains no sensitizer. In the thermal recording materials of the present invention, substantially no color is developed at a temperature of 120.degree. C. while color development can be caused in response to heating with a thermal head or a laser beam. The developed color on the material can be erased upon contacting with alcoholic solvents, depending on the thiourea compound contained in the color developing layer. After erasure of the image, the material can be used again for recording with a thermal head or a laser beam.

In a thermal recording sheet having a thermal recording layer containing a colorless or pale colored dye precursor and a color developer reactable with the dye precursor upon heating to develop a color, a dimerized or trimerized urea compound is used as the color developer to obtain a thermal recording sheet which is superior in ground color stability and a thermal recording sheet having a reversible recordability.

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Tokyo, Japan

Hideki Hayasaka