Jujo Paper Co., Ltd.

Nippon Paper Industries Co., Ltd.

Yoshitomi Pharmaceutical Industries, Ltd.

Asahi Denka Kogyo Kabushiki Kaisha

Nippon Paper Industries, Ltd.

Adeka Fine Chemical Co., Ltd.

Tomoaki Nagai

Toshimi Satake

Akio Sekine

Kaoru Hamada

Toshiaki Minami

Miyuki Yokoyama

Hiroshi Fukui

Fumio Fujimura

Toshiyuki Takano

Yoshimi Midorikawa

Yoshihide Kimura

Tadakazu Fukuchi

Hideki Hayasaka

Hidetoshi Yoshioka

Reiji Ohashi

Yutaka Wakita

Yukiko Ryu

Yukiko Uehori

Hiroshi Ueda

Toshio Kaneko

Ryoichi Kinishi

Yuji Tsuzuki

Reiko Sato

Hideyuki Yamanashi

Hideo Hachimori

Ryuzo Minakami

Nobuhiro Kudoh

A thermally sensitive recording medium which has thermally sensitive recording layer containing colorless or pale colored basic leuco dye and organic color developer as main components on a substrate, wherein said thermally sensitive recording layer contains diphenylsulfone bridgeable type compound represented by general formula (1) and at least one compound represented by general formula (1).

Thermally sensitive recording medium

The thermally sensitive recording medium having sufficient color developing density and develops sepia color or light brown color. The color difference a* value of developed image of said thermally sensitive recording medium regulated by JIS-Z-8729 is within the region of 0&tilde;40 and b* value is within the region of 0&tilde;55.

A thermally sensitive recording medium having sufficient color developing density and which develops russet or wine red color. The recording medium incorporates a dye precursor which includes at least one red color developing leuco dye having a maximum absorption wavelength of 480 to 570 nm and at least one black color developing leuco dye with maximum absorption wavelengths at 420 to 480 nm and 550 to 640 nm. The color difference a* value of developed image of said thermally sensitive recording medium, measured according to JIS-Z-8729 is within the region of 0 to 50 and b* value is within the region of &minus;15 to 10.

A thermal sensitive recording medium which has a feature to change the color of recorded pattern slowly and spontaneously after development, and the recorded pattern which has several days passed can be easily distinguished from that of just after development. Said thermal sensitive recording medium contains 4-hydroxybenzoic acid ester represented by general formula (I) as a color developer and uses triphenylmethane-based leuco dye and reddish color developing leuco dye whose maximum absorption wave length is 450.about.560 nm as a dye precursor. ##STR1## In this formula, R represents unsubstituted or substituted lower alkyl group of carbon number 1-7 or benzyl group.

Spontaneously color changing type thermal sensitive recording medium

A phenanthridine derivative metal complex of formula 1 having a large absorption in the near-infrared range and a reduced absorption in the visible range, which phenanthridine derivative metal complex is used in a transparent recording medium: ##STR1## where M is a metal atom, and X is a negative ion.

Phenanthridine derivatives and metal complexes thereof used for

An acridine derivative metal complex of formula 2 having a large absorption in the near-infrared range and a reduced absorption in the visible range, which acridine derivative metal complex is used in a transparent recording medium: ##STR1## where M is a metal atom, and X is a negative ion.

Acridine derivative metal complexes used for transparent recording

A thermal recording medium comprising a substrate having thereon a recording layer containing a colorless or pale colored dye precursor, and a color developer reactable with the dye precursor to develop a color as main ingredients, wherein the color developer includes at least one compound of Formula (1): and the recording layer contains at least one methylolated fatty acid amide of Formula (2): ##STR1## (wherein X denotes oxygen atom or sulfur atom; and R denotes substituted or unsubstituted phenyl group, naphthyl group, aralkyl group, a lower alkyl group of 1 to 6 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, or a lower alkenyl group of 2 to 6 carbon atoms. Z denotes a lower alkyl group of 1 to 6 carbon atoms or an electron attracting group. n is an integer from 0 to 4, and p is an integer from 1 to 5, satisfying n+p .ltoreq.5.).

Thermal recording medium

In a thermal sensitive recording medium comprising a thermal sensitive color developing layer which includes a basic leuco dye and an organic color developer on a substrate, characterized by the said thermal color developing layer includes 0.01-0.9 parts of aminobenzenesulfonamide derivatives indicated by general formula (I) based on 1 part of color developer and also includes at least one kind of methylolated fatty acid amide indicated by general formula (II) in proportion of 0.01-2 parts based on 1 part of color developer. ##STR1## (wherein, 'X' indicates an oxygen or sulfur atom, 'R' indicates non-substituted or substituted phenyl group, naphthyl group, aralkyl group, lower alkyl group of carbon number 1-6, cycloalkyl group of carbon number 3-6 or lower alkenyl group of carbon number 2-6. 'Z' indicates lower alkyl group of carbon number 1-6 or electron attractive group. 'n' indicates an integer from 0 to 4 and 'P' indicates an integer from 1 to 5, wherein satisfies the numerical formula of n+p.ltoreq.5)

Thermal sensitive recording medium

An acridine derivative metal complex of formula 1 or formula 2 having a large absorption in the near-infrared range and a reduced absorption in the visible range, which acridine derivative metal complex is used in a transparent recording medium: ##STR1## where M is a metal atom, and X is a negative ion.

Acridine derivatives and metal complexes thereof used for transparent

A thermal sensitive recording sheet comprising a substrate having thereon a thermal sensitive color developing layer mainly composed of basic leuco dye and an organic color developer, characterized by said thermal sensitive developing layer includes derivatives of amino benzene sulfone amide indicated by general formula (I) as an organic color developer, and includes sulfone amide compound indicated by general formula (II) as a sensitizer by amount of 0.01-2 parts based on 1 part of the color developer indicated by general formula (I). ##STR1## wherein 'X' indicates an oxygen or sulfur atom, 'Y' indicates a lower alkyl group of carbon number 1-4 or electron attracting group and 'm' indicates an integral number from 0 to 4. 'R' indicates a non-substituted or a substituted phenyl group, aralkyl group, lower alkyl group of carbon number 1-6, cycloalkyl group of carbon number 3-6, lower alkenyl group of carbon number 2-6 or naphthyl group. ##STR2## wherein 'Z' indicates a lower alkyl group of carbon number 1-6 or electron attracting group. 'n' indicates an integral number from 0 to 2.

Thermal sensitive recording sheet

Discloses a thermal sensitive recording sheet which has features of high sensitivity, excellent heat resistance, excellent water proof and excellent durability to oil. The thermal sensitive color developing layer is mainly composed of a basic achromatic dye including the compound indicated by general formula (I) or (II), an organic color developer and a stabilizer indicated by general formula (III). And the said layer is arranged on a substrate and forms the thermal sensitive recording sheet. ##STR1##

To provide a reversible multi-color thermal recording medium or a reversible multi-color optical recording medium which uses novel urea and thiourea derivatives and has excellent heat resistance. A reversible multi-color thermal recording medium having an irreversible thermal composition containing a colorless or pale basic achromatic dye and an organic color developer as main components and a reversible thermal composition containing a colorless or pale basic achromatic dye and an organic color developer as main components laminated on a support, the organic color developer contained in the irreversible thermal composition being an irreversible heat-resistant color developer and the organic color developer contained in the reversible thermal composition being a reversible heat-resistant color developer.

Reversible multi-color thermal recording medium

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 medium or an optically recordable thermal recording medium including a substrate having thereon a recording layer containing a colorless or pale colored dye precursor and a color developer reactable with the dye precursor to develop a color as main ingredients, the color developer includes at least one aminobenzenesulfonamide derivative of Formula (1): ##STR1## (wherein X denotes oxygen atom or sulfur atom; and R denotes substituted or unsubstituted phenyl group, naphthyl group, aralkyl group, a lower alkyl group of 1 to 6 carbon atoms, cycloalkyl group, or a lower alkenyl group of 2 to 6 carbon atoms. Z denotes a lower alkyl group of 1 to 6 carbon atoms or an electron attracting group. n is an integer from 0 to 4.).

Growing community of inventors

Tokyo, Japan

Tomoaki Nagai