| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat-sensitive recording medium having small fogging even by exposing under a high temperature condition, good color developing and excellent preservability of a recorded part. SOLUTION: The heat-sensitive recording medium comprises a heat-sensitive thermal recording layer containing a colorless or pale leuco dye of an electron donor and a developer of an electron acceptor and provided on a support. In this medium, as the colorless or pale leuco dye, at least one of 6'-(diethylamino)-2'-([3-(trifluoromethyl)phenyl]amino]-spiro[isobenzo furan-1(3H), 9'-(9H)xanthene]-3-on and 4-anilino-3-methyl-6-dibutylaminofluoran is contained. As the developer, 2,4-dihydroxyphenylsulfone is contained. A color developing density when a heating block of 150 deg.C is press bonded to a heat-sensitive sheet for 1 s at 800 g/cm<2> is 1.20 or more in terms of an OD value, and a color developing density when a heating block of 100 deg.C is press bonded to a heat-sensitive sheet for 1 s at 800 g/cm<2> is 0.20 or less in terms of the OD value. |
