Patent ID: 7098168

Claim:
A thermosensitive recording material comprising: a support; and a thermosensitive recording layer formed on the support, the thermosensitive recording layer containing an electron-donating colorless dye and an electron-accepting accepting compound which develops color upon a reaction with the electron-donating colorless dye, wherein the thermosensitive recording material satisfies all of the following conditions (1) to (3): (1) an image density when thermal printing is performed from a side, of the support, having the thermosensitive recording layer with printing energy of 15.2 mJ/mm 2 is 1.20 or more, and the thermosensitive recording material is used for a recording device having a printing speed of 10 cm/sec or more; (2) the thermosensitive recording material contains a sensitizer comprising at least one compound selected from the group consisting of 2-benzyloxynaphthalene, dimethylbenzyloxalate, m-terphenyl, ethyleneglycol tolyl ether, p-benzyl biphenyl, 1,2-diphenoxymethyl benzene, diphenyl sulfone and 1,2-diphenoxy ethane, and an image density after the thermosensitive recording material is brought into contact with a heat source of 70° C. for 5 seconds is 0.15 or less; (3) the electron-accepting compound is a compound represented by the following Formula (1): R 1 -Ph-SO 2 R 2 Formula (1) wherein R 1 represents a hydroxyl group or an alkyl group, R 2 represents -Ph, —NH-Ph, -Ph-OR 3 or —NH—CO—NH-Ph, R 3 represents an alkyl group, Ph represents a phenyl group and may be substituted with a substituent containing —SO 2 R 2 , and a volume-averaged grain size of the electron-donating colorless dye and electron-accepting compound is in a range of 0.5 to 1.0 μm.