Bis[1-(2-A-2-B)ethenyl]} [2-R.sup.2 -4-X-phenyl- or 1-(2-R.sup.2 -4-X-phenyl) ethenyl]methanes useful as color formers, particularly in transfer imaging, pressure sensitive and thermal-responsive carbonless duplicating systems, are prepared by the interaction of two molecular proportions of the corresponding 1-A-1-B-ethene with the appropriate 2-R.sup.2 -4-X-phenyl-(CH.dbd.CH).sub.n --CHO presence of an acidic catalyst.
Bis[1-(2-A-2-B)
乙烯基]} [2-R.sup.2 -4-X-苯基或1-(2-R.sup.2 -4-X-苯基)
乙烯基]
甲烷可用作发色剂,特别适用于转印成像、压敏和热响应的无碳复写系统,通过相应的1-A-1-B-
乙烯与适当的2-R.sup.2 -4-X-苯基-(CH.dbd.CH).sub.n --CHO在酸性催化剂存在下的相互作用制备。