Pressure sensitive or thermographic recording material - contg. aromatic hemiacetal as colour developer giving spontaneous stable copy

摘要

Pressure-sensitive or thermographic recording material contains as developer for the colour former (I), hemi-acetal cpd(s). (II) of the formula Ar-(O-CH(OH)-Q-Xm)n (in which Ar is a mono- or bi-nuclear aromatic gp. Q is C or an (un)substd. hydrocarbyl gp. X is halogen m and n are 1 to 3, pref. n is 1 or 2). (II) are practically colourless and odourless and very reactive with the usual (I), giving spontaneous, stable and nonfading copies.