公开(公告)号：JPS6272781A

公开(公告)日：1987-04-03

申请号：JP21329585

申请日：1985-09-26

Applicant: MITSUI TOATSU CHEMICALS

Inventor： ITO NAOTO ,  AIGA HIROSHI ,  TAKUMA HIROSUKE ,  KINOSHITA MITSUNORI ,  MIKOTA TAMIO

IPC: C09B1/28 ,  C09K19/60 ,  G02F1/13 ,  G02F1/137

Abstract: PURPOSE:To provide the titled novel anthraquione-based coloring matter having specific structure, of large dichromatic ratio, high in durability, highly compatible with liquid crystal, giving adequate color-developing ability even with small amount, suitable for liquid crystal display in watches, etc. CONSTITUTION:For example, a coloring matter of formula I is allowed to react with dimethyl sulfoxide, etc. at 95 deg.C for 6hr followed by discharge into water. The resultant system is subjected to ammonium persulfate followed by filtration, washing with water, drying, etc., thus obtaining the objective coloring matter of formula II (R , R are each 1-20C alkyl) having absorption at wavelength between 700 and 800nm.