Nippon Paper Industries Co., Ltd.

Api Corporation

Mitsubishi Chemical Corporation

Yoshimune Aosaki

Mamoru Suga

Yukiko Sato

Yoshimi Midorikawa

Katsuto Ohse

Akihito Ogino

Tatsuo Nagai

Junpei Natsui

Hiroshi Kohama

Keiichiro Inada

Mai Higuchi

Tatsuyuki Kurihara

Mai Kaneko

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.

Phenolsulfonic acid aryl ester derivative, and heat-sensitive recording material using same

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. The thermosensitive recording medium of the present invention that uses a combination of the diphenyl sulfone derivative and a specific phenol derivative in the thermosensitive color developing layer has a good color developing sensitivity and an improved balance among the properties such as moist heat resistance, plasticizer resistance and the like.

Thermosensitive recording medium

Provided are a coating solution for a thermosensitive color developing layer of excellent storability wherein color development during its storage or during producing a thermal recording material is suppressed, and a thermal recording material with excellent print portion (image portion) storability and suppressed staining in the background color (white background). A coating solution for a thermosensitive color developing layer, which comprises a colorless or pale-colored electron-donating leuco dye, a hindered phenol compound and, as an electron-accepting developer, a diphenylsulfone derivative represented by the following formula (1): wherein the aforementioned hindered phenol compound has an average particle size (D50) of not more than 0.5 &#x3bc;m, and the coating solution has a color tone a* of not less than &#x2212;4.0 as measured according to JIS Z 8729 and a whiteness W of not less than 62 as measured according to JIS Z 8715.

Coating solution for heat-sensitive color-developing layer, and heat-sensitive recording material

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. A thermal recording material comprising a support and a thermal recording layer comprising a colorless or pale basic leucodye and a developer to develop color of the basic leucodye, wherein the aforementioned developer comprises a first developer which is a condensate or condensed composition represented by the following formula (I) and a second developer other than the first developer, and the proportion of the first developer to the total amount of the developers is not less than 2 wt % and less than 50 wt %: wherein R is a hydrogen atom, a halogen atom, a hydroxyl group, a lower alkyl group, an alkoxyl group, a cyano group, a nitro group, an aryl group or an aralkyl group, R in the number of m may be the same or different, m is an integer of 0 to 3, n is an integer of 0 to 3, and X and Y are each a hydrogen atom, an alkyl group or an aryl group.

Thermal recording material

Growing community of inventors

Fukuoka, Japan

Yoshimune Aosaki