Abstract: The present invention provides a thermosensitive recording medium with excellent color developing sensitivity, moist heat resistance and plasticizer resistance, as well as excellent heat resistance, background coloring, light resistance and the like in the printed image. A diphenyl sulfone derivative containing a hydroxyl group on one end and an alkoxy group on the other end has a higher melting point than the one containing hydroxyl groups on both ends. As a result, the thermosensitive recording medium obtained using the diphenyl sulfone derivative as the color developing agent in the thermosensitive color developing layer has excellent heat resistance. However the color developing sensitivity of the thermosensitive recording medium generally declines simultaneously, when a color developing agent with a high melting point is ordinarily used.

Abstract: The present invention provides a thermosensitive recording medium, which has a satisfactory color developing sensitivity, an excellent general printability (surface strength) and an excellent anti-sticking property. The thermosensitive recording layer of the thermosensitive recording medium of the present invention contains an alkylketene dimer. Without forming a protecting layer, the thermosensitive recording medium of the present invention is superior in color developing sensitivity, general printability (surface strength) and anti-sticking property.

Abstract: The present invention is a thermally sensitive recording medium containing a thermally sensitive color developing layer containing a colorless or pale colored basic leuco dye and a color-developing agent as the main components on a substrate, wherein the thermally sensitive recording layer contains an acrylic polymer obtained by the copolymerization of an alkyl acrylate, alkyl methacrylate and vinylsilane as monomer components and a colloidal. Further, the present invention is a thermally sensitive recording medium, wherein the colloidal silica possesses a chain structure.

Abstract: The present invention is a thermally sensitive recording medium comprising a thermally sensitive color developing layer containing colorless or pale colored basic leuco dye and a color developing agent as main components on a substrate, wherein said thermally sensitive recording layer is comprising an acrylic polymer obtained by copolymerization of alkyl acrylate, alkyl methacrylate and vinylsilane as monomer components and a colloidal silica, further, the present invention is a thermally sensitive recording medium, wherein said colloidal silica is possessing chain structure.

Abstract: A thermally recording sheet which has high sensitivity in color development, satisfactory background heat resistance, and a satisfactory background color. The sheet contains a dihydroxydiphenylsulfone compound represented by general formula (1) as a color developer and a sulfonamide represented by general formula (2). In the formula, R1 and R2 each represents C1-8 alkyl, alkenyl, or halogeno; and a and b each is an integer of 0 to 3. In the formula, R3 represents C1-66 alkyl or electron-attracting group; and n is an integer of 0 to 2.

Abstract: A multi chromatic thermally sensitive recording medium comprising, a higher temperature color developing layer containing dye precursor and an organic color developer that reacts with said dye precursor and develops color by heating, and at least one lower temperature color developing layer that develops different color from that of said higher temperature color developing layer and develops color by lower temperature than the color developing temperature of said higher temperature color developing layer laminated in order on a substrate, wherein an organic color developer contained in said higher temperature color developing layer contains said diphenylsulfone bridgeable type compound represented by general formula (1) and/or said 3-{[(phenylamine)carbonyl]amino}benzenesulfoneamide compound represented by general formula (2), wherein, X and Y can be different and indicates a saturate or an unsaturated liner or grafted hydrocarbon group of carbon number 1 to 12 which can

Abstract: A thermal recording material which has high sensitivity in color development and a high whiteness of the background and is excellent in image retention and heat resistance. The thermal recording material contains a dihydroxydiphenylsulfon compound represented by general formula (1) as an organic color developer and 3-di-n-pentylamino-6-methyl-7-anilinofluoran as a colorless basic dye. (In the formula, R1 and R2 each represents C1-8 alkyl, alkenyl, or halogeno; and p and q each is an integer of 0 to 3.

Abstract: A thermally sensitive recording paper having a recording surface which when a postage stamp or a revenue stamp is adhered to the recording surface requires at least ten cycles of a removal test procedure to remove at least one third of the adhered surface of the stamp from the recording surface of the thermally sensitive recording paper, wherein the removal test procedure comprises adhering the postage stamp or revenue stamp to the recording surface of the thermally sensitive recording paper, hanging the recording paper over an iron bar of about 8 mm diameter with the postage stamp or revenue stamp on an outer surface of the recording paper, adjusting the recording paper such that equal lengths are on either side of the iron bar, attaching to one end of the thermally sensitive recording paper a weight of about 500 g, holding the other end of the thermally sensitive recording paper by hand and carrying out a pull down ant put back cycle motion of the hand to move the postage stamp or revenue stamp over the iro

Abstract: A thermal recording sheet which is satisfactory in sensitivity in color development, background heat resistance, and background color, is free from powdering, and has excellent image retention. The sheet comprises supporting and formed thereon a thermal color development layer containing as main components a colorless or light-colored basic dye and an organic color developer, and is characterized in that the thermal color development layer contains at least one dihydroxydiphenyl sulfone compound represented by general formula (1) as the organic color developer, and further contains either at least one saturated fatty acid monoamide represented by general formula (2) in an amount of 1.5 to 5 parts per part of the organic color developer or a combination of at least one saturated fatty acid monoamide represented by general formula (2) and at least one diphenyl sulfone derivative represented by the general formula (3).

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: 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: 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 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: In a thermal recording sheet including a substrate having thereon a thermal color developing layer containing colorless or pale colored basic achromatic dye and an organic color developer, the thermal color developing layer contains aluminium hydroxide and a urea-formaldehyde resin pigment. The thermal recording sheet is small in abrasion of the recording head and adherence of depositions to the head even after long-run recording, and friction staining in unrecorded portion due to the recording head and change in gloss in unrecorded portion during recording are small.

Abstract: A thermal recording medium wherein ultraviolet absorbent is included in undercoat layer and/or in thermal sensitive color developing layer, ultraviolet isolator consisted of calcined particle which is flaky pigment whose refractive index is 1.5 to 1.6 and whose surface is coated with insoluble cerium compound and amorphous silica is included in thermal sensitive color developing layer and/or in protective layer, and fluorescent dye is included in protective layer.