Nippon Paper Industries Co., Ltd.

Mitsubishi Chemical Corporation

Api Corporation

Katsuto Ohse

Yukiko Sato

Yoshimi Midorikawa

Yoshimune Aosaki

Yukiko Satou

Yasuaki Matsumori

Mamoru Suga

Keiichiro Inada

Mai Higuchi

Takurou Inoue

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

A thermosensitive recording medium having excellent image quality and surface strength is provided. The thermosensitive recording medium having excellent image quality and surface strength is obtained by containing a saturated fatty acid amide in the substrate to lower the density of the substrate. The thermosensitive recording medium of the present invention has an adequate general printability and problems such as print through are avoided. Furthermore, the thermosensitive recording medium of the present invention can assure adequate image quality and general printability even when an undercoat layer is not installed.

Thermosensitive recording medium

The present invention present a thermosensitive recording medium having excellent printed image quality on a thermosensitive recording surface, particularly for bar code readability, and also good record density and recording property after storage. In a thermosensitive recording medium obtained by installing on a substrate a thermosensitive recording layer containing a colorless or pale electron donating leuco dye and an electron accepting coloring agent, the water drop absorbency of the surface on which a thermosensitive recording layer is installed on said substrate is adjusted to at least 50 seconds by having at least 5 wt. % of mechanical pulp present in the substrate and controlling the sizing agent treatment of the substrate.

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

Growing community of inventors

Tokyo, Japan

Katsuto Ohse