| 摘要 |
PURPOSE:To improve the electrocharge stability due to the lapse of time by incorporating a salt composed of a dyestuff having an amino group (except a triaryl type dyestuff) and a polymer acid in which at least a part of the polymer acid is soluble to a carrier liquid. to the carrier liquid having a high insulating property, thereby maintaining a good positive electric charging property of the carrier liquid. CONSTITUTION:The dyestuff capable of forming the salt is the dyestuff capable of forming the salt with the prescribed polymer acid, and is not specified. The concrete example of said dyestuff is the dyestuff which is selected from the group composed of a basic azo dyestuff, a basic diphenyl dyestuff, a thiazine dyestuff and an anthraquinone dyestuff, and has the amino group capable of forming the salt with the prescribed polymer acid. The polymer acid usable to forming the salt is the polymer acid soluble to the carrier liquid obtd. by copolymerizing the additional polymerizable carboxylic acid such as an acrylic acid, a methacrylic acid, a maleic acid, a fumaric acid and a monomer shown by the formula. |
