1. Field of the Invention
The present invention relates to a catalyst for preparing a condensation polymerization resin for a toner which is used for developing electrostatic latent images formed in electrophotography, electrostatic recording method, electrostatic printing method, and the like, a condensation polymerization resin composition comprising the catalyst, and a toner comprising the condensation polymerization resin composition.
2. Discussion of the Related Art
Recently, the durability of a toner, especially suppression of toner adhesion which is a so-called toner spent, has become a serious problem, from the viewpoints of higher speeds and smaller scales of copy machines and printers. Therefore, various studies have been made such as a toner defining its melting properties (Japanese Patent Laid-Open No. Hei 9-258471 and the like), a toner defining the composition of a resin binder (Japanese Patent Laid-Open No. Hei 8-262796, 2000-147827, and the like), a toner defining its wax component (Japanese Patent Laid-Open No.2001-188387), a toner defining its dissolubility in tetrahydrofuran or the like (Japanese Patent Laid-Open No. 2000-181119), a toner defining an external additive such as silica and a charge control agent (Japanese Patent Laid-Open No. 2000-155443), and the like. Although effects are obtained to a certain extent, further improvements therefor have been desired.
The present inventor have conducted studies based on the thought that one of the causations of lowering the durability of the toner is in the generation of the lower molecular compounds due to unsatisfactory reaction activity and hydrolytic resistance of a catalyst conventionally used in the preparation of a condensation polymerization resin-based resin binder for a toner, such as a tin compound such as dibutyltin oxide, a titanium compound such as tetra-n-butyl titanate, a germanium compound such as germanium oxide, and a manganese compound such as manganese oxide (Japanese Patent Laid-Open Nos. 2000-56513 and Hei 3-41470). As a result, the present inventors have found a catalyst for a condensation polymerization resin for a toner, which is useful in improvement of durability of toner. The present invention has been accomplished thereby.
An object of the present invention is to provide a catalyst for preparing a condensation polymerization resin, which is effectively used in the preparation of a binder resin for a toner having excellent durability.
Another object of the present invention is to provide a condensation polymerization resin composition comprising the catalyst, the condensation polymerization resin composition being useful as a resin binder for a toner which has excellent durability, and a toner comprising the condensation polymerization resin composition, the toner having excellent durability.
These and other objects of the present invention will be apparent from the following description.