Binder resin for electrostatic image developing toner, binder resin liquid dispersion for electrostatic image developing toner, electrostatic image developing toner, and production processes thereof

#1. Field of the Invention

#The present invention relates to a binder resin for an electrostatic image developing toner which is used when an electrostatic latent image formed by an electrophotographic process, an electrostatic recording process or the like is developed with a developer, and also relates to an electrostatic image developing toner produced by kneading and pulverizing the binder resin. Furthermore, the present invention relates to a binder resin liquid dispersion for an electrostatic image developing toner, produced from the binder resin, and an electrostatic image developing toner produced by using the binder resin liquid dispersion. In addition, the present invention relates to an electrostatic image developer using the electrostatic image developing toner, and an image forming method.

#2. Description of the Related Art

#The binder resin for an electrostatic image developing toner (in the present invention, the “electrostatic image developing toner” is sometimes simply referred to as a “toner”) of the present invention is a binder resin for a toner, obtained by the polycondensation reaction of a polycarboxylic acid and a polyol, wherein from 50 to 100 mol % of the polycarboxylic acid comprises a compound represented by formula (1) and/or formula (2), from 50 to 100 mol % of the polyol comprises a compound represented by formula (3), and the content of a catalyst-originated metal element in the resin is 100 ppm or less: R1OOCA1mB1nA11COOR1′  (1) (wherein A1 is a methylene group, B1 is an aromatic hydrocarbon group, R1 and R1′ each is a hydrogen atom or a monovalent hydrocarbon group, 1≦m+l≦12, and 1≦n≦3); R2OOCA2pB2qA2rCOOR2′  (2) (wherein A2 is a methylene group, B2 is an alicyclic hydrocarbon group, R2 and R2′ each is a hydrogen atom or a monovalent hydrocarbon group, 0≦p≦6, 0≦r≦6, and 1≦q≦3); HOXhYjXkOH  (3) (wherein X is an alkylene oxide group, Y is a bisphenol structure group, 1≦h+k≦10, and 1≦j≦3).

#A conventional polyester resin is generally polymerized at a high temperature of 200° C. or more in the presence of a metal catalyst such as tin and titanium. On the other hand, in the case of using a polyester as the resin for a toner, chargeability, more specifically, uniform chargeability with less difference in the charged amount among particles, is demanded. However, the metal contained in the metal catalyst generally has positive chargeability and the polyester has negative chargeability, as a result, there may arise repulsion or the like among toner particles due to the non-uniform presence of a residual metal catalyst. Generally, in the case of a two-component developer, electrification of a toner is controlled by a carrier, but the above-described slight repulsive force of a toner separated from a carrier in the development step, transfer step or the like cannot be controlled and this appears in the form of, for example, roughness in the edge part of a fine line.

#In the present invention, the amount of this metal is controlled, whereby roughness in the edge part of a fine line, which has been heretofore difficult to control, is controlled and at the same time, a polyester reduced in the energy amount consumed for the production as compared with a conventional polyester is obtained.