Abstract: The present invention provides a compound represented by the formula (1). The compound represented by the formula (1) is a developing agent superior in both color-developing sensitivity with low energy and image stability [in the following formula, wherein R1 is a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or an aralkyl group, R2 in the number of m are each independently an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkoxy group, a halogen atom, a hydroxy group, a cyano group, a nitro group, a carboxy group or an amino group, R3 in the number of n are each independently an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkoxy group, a halogen atom, a hydroxy group, a cyano group, a nitro group, a carboxy group or an amino group, and m and n are each independently an integer of 0-4.

Abstract: The invention provides a phenolsulfonic acid aryl ester represented by formula (1) wherein each symbol is as defined in the description. The phenolsulfonic acid aryl ester is useful as a developer to provide a thermal recording material with good color-developing sensitivity, image density when printed at a low application energy (i.e., high start-up sensitivity), and heat and plasticizer resistance. The invention also provides a thermal recording material using the developer.

Abstract: The present invention provides a compound represented by the formula (1). The compound represented by the formula (1) is a developing agent superior in both color-developing sensitivity with low energy and image stability [in the following formula, wherein R1 is a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or an aralkyl group, R2 in the number of m are each independently an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkoxy group, a halogen atom, a hydroxy group, a cyano group, a nitro group, a carboxy group or an amino group, R3 in the number of n are each independently an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkoxy group, a halogen atom, a hydroxy group, a cyano group, a nitro group, a carboxy group or an amino group, and m and n are each independently an integer of 0-4.

Abstract: The invention provides a phenolsulfonic acid aryl ester represented by formula (1) wherein each symbol is as defined in the description. The phenolsulfonic acid aryl ester is useful as a developer to provide a thermal recording material with good color-developing sensitivity, image density when printed at a low application energy (i.e., high start-up sensitivity), and heat and plasticizer resistance. The invention also provides a thermal recording material using the developer.

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: Provided is a thermal recording material superior in color development sensitivity, and having good preservation properties such as in heat resistance, moisture resistance, water resistance and the like.

Abstract: The present invention relates to a developer mixture for a thermal recording material, which comprises a mixture of the first organic developer comprising a condensate or a condensed composition represented by the formula (I): wherein R is a lower alkyl group or an aralkyl group, n is an integer of 0 to 5, and X and Y are each a hydrogen atom, an alkyl group or an aryl group, and the second organic developer other than the first organic developer (except 2,2-bis(3-methyl-4-hydroxyphenyl)propane), a developer mixture for a thermal recording material, and a thermal recording material having a heat-coloring layer containing the developer mixture. Using the developer mixture for a thermal recording material of the present invention, a thermal recording material sufficiently satisfying the recent requirement for high sensitivity, and having superior preservation stability of color images and non-image areas can be realized.

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: Provided is a thermal recording material superior in color development sensitivity, and having good preservation properties such as in heat resistance, moisture resistance, water resistance and the like.

Abstract: The present invention relates to a developer mixture for a thermal recording material, which comprises a mixture of the first organic developer comprising a condensate or a condensed composition represented by the formula (I): wherein R is a lower alkyl group or an aralkyl group, n is an integer of 0 to 5, and X and Y are each a hydrogen atom, an alkyl group or an aryl group, and the second organic developer other than the first organic developer (except 2,2-bis(3-methyl-4-hydroxyphenyl)propane), a developer mixture for a thermal recording material, and a thermal recording material having a heat-coloring layer containing the developer mixture. Using the developer mixture for a thermal recording material of the present invention, a thermal recording material sufficiently satisfying the recent requirement for high sensitivity, and having superior preservation stability of color images and non-image areas can be realized.

Abstract: The object of the present invention is to provide a novel developer capable or realizing a thermal recording material superior in preservation stability (i.e., heat resistance, moisture resistance) of color images and non-image areas, while satisfying the recent request for high sensitivity, and a thermal recording material using the developer.

Abstract: The object of the present invention is to provide a novel developer capable or realizing a thermal recording material superior in preservation stability (i.e., heat resistance, moisture resistance) of color images and non-image areas, while satisfying the recent request for high sensitivity, and a thermal recording material using the developer.

Abstract: The developer for a thermal recording material of the present invention comprises a condensed composition consisting of, of condensates represented by the formula (1): 1