Abstract: The present invention provides a laser recording thermally sensitive recording medium comprising a thermally sensitive recording layer containing at least a photo absorbing material which absorbs laser ray and covert it to heat, an electron donning leuco dye and an electron accepting color developing agent on a substrate, wherein said electron donning leuco dye contains a leuco dye which absorbs the ray of visible range and a leuco dye having main wave length of absorption at the ray of 600 nm or longer.

Abstract: The present invention provides a laser recording thermally sensitive recording medium comprising a thermally sensitive recording layer containing at least a photo absorbing material which absorbs laser ray and covert it to heat, an electron donning leuco dye and an electron accepting color developing agent on a substrate, wherein said electron donning leuco dye contains a leuco dye which absorbs the ray of visible range and a leuco dye having main wave length of absorption at the ray of 600 nm or longer.

Abstract: 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). In general formula (2), X and Y can be different and indicates a saturated or an unsaturated liner or grafted hydrocarbon group of carbon number 1-12 which can possess ether bond, or indicates wherein R indicates a methylene group or an ethylene group, T indicates a hydrogen atom or an alkyl group of carbon number 1-4, and R1-R6 independently indicate a halogen atom, an alkyl group of carbon number 1-6, or an alkenyl group, further, m, n, p, q, r, t indicate an integer number of 0-4 and when are bigger than 2, R1-R6 can be different, and a is an integer of 0-10.

Abstract: The thermally sensitive recording medium having sufficient color developing density and develops navy blue or grayish blue color. The color difference L* value a* value and b* value of developed image of said thermally sensitive recording medium regulated by JIS-Z-8729 are within the regions of, A. L* value is 30˜50, a* value is −15˜0 and b* value is −30˜10, B. L* value is 30˜50, a* value is 0˜10 and b* value is −30˜0 or C. L* value is 30˜50, a* value is 10˜20 and b* value is −30˜15.

Abstract: 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˜40 and b* value is within the region of 0˜55.

Abstract: 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 −15 to 10.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.).R.sub.1 -CONHCH.sub.2 OH (2)(wherein R.sub.1 denotes an alkyl group of 11 to 21 carbon atoms).

Abstract: 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)R.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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):(R--NH (C.dbd.S) NH)n--Z (1)(wherein R denotes a substituted or unsubstituted alkyl, cycloalkyl, aryl, aralkyl, or alkenyl. n is an integer of 2 or more, and Z denotes a group having a valence of 2 or more.). The optical recording medium is superior in heat resistance and plasticizer resistance of the recorded image, heat resistance of background, water resistance, and moisture resistance.).

Abstract: 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.).

Abstract: A thermal recording sheet wherein a compound of Formula (I) or (II) is contained in a thermal color developing layer including a basic colorless dye and an organic color developer as main ingredients: ##STR1## (wherein A denotes hydrogen atom, an alkyl group of C.sub.1 to C.sub.4, an alkoxy group of C.sub.1 to C.sub.4, hydroxy group, or nitro group. R.sub.1, R.sub.2, and R.sub.3 are hydrogen atom, an alkyl group of C.sub.1 to C.sub.4, an alkoxy group of C.sub.1 to C.sub.4, hydroxy group, or nitro group. R.sub.1 and R.sub.2 may combine with each other to form an aromatic ring. Y is sulfur or oxygen atom.), ##STR2## (wherein B denotes hydrogen atom, an alkyl group of C.sub.1 to C.sub.4, an alkoxy group of C.sub.1 to C.sub.4, hydroxy group, or nitro group. R.sub.1, R.sub.2, and R.sub.3 are hydrogen atom, an alkyl group of C.sub.1 to C.sub.4, an alkoxy group of C.sub.1 to C.sub.4, hydroxy group, or nitro group. R.sub.1 and R.sub.2 may combine with each other to form an aromatic ring. Y is sulfur or oxygen atom.).

Abstract: 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.

Abstract: 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.