IT1105406B - Pressure-sensitive and thermo-reactive recording materials - contg. carbazolyl-bis:amino-phenyl or bis:indolyl-methane cpds. as colour formers - Google Patents

Abstract

Pressure- or heat-sensitive recording material has a colour forming system contg. as colour former, carbazolylmethane cpd(s) of formula (I): (in which Y is an aminophenyl or indolyl gp. of formula (II) or (III); X1 and X2 are each H; 1-12C alkyl (opt. substd by halogen, OH, CN or lower alkoxy), cycloalkyl, or phenyl or benzyl (opt. substd. by halogen, lower alkyl or lower alkoxy); or X1 and X2 together with the N atom form a 5- or 6-membered heterocycle; X3 is H, halogen, nitro, lower alkyl or lower alkoxy; R1 and Z1 are each H, 1-12C alkyl (opt. substd. by halogen, OH, CN or lower alkoxy), 1-12C alkenyl, 1-12C acyl, or phenyl or benzyl (opt. substd. by halogen, lower alkyl, lower alkoxy or nitro), Z2 is H, lower alkyl or phenyl, and A, B and D can be substd. by CN, nitro, halogen, lower alkyl, lower alkoxy or lower alkylcarbonyl). (I) which are normally colourless or pale in colour, give intense orange, red, violet and blue and green shades with excellent fastness, in contact with acid developers, both clays and phenolic substances. They are also useful in conjunction with other colour formers for the prodn. of (maine) blue, grey or black shades. (I) are esp. useful as slowly developing colour formers for pressure-sensitive copying and registering materials. In an example, a material using microencapsulated N-ethylcarbazolyl-bis(4-N-methyl-N-phenylaminophenyl)-methane in conjunction with paper coated with Silton clay gave an intense blue copy with excellent light-fastness, the rate of development depending on the pH of the clay suspension used for coating.