申请人:MITSUBISHI RAYON CO., LTD.
公开号:EP0333498A2
公开(公告)日:1989-09-20
Disclosed is a crosslinked polyester for a toner, and a process for its manufacture wherein the polyester has an acid value of 5 to 20 mgKOH/g, a flow index of 0.1 x 10⁻⁴ to 300 x 10⁻⁴ ml/sec and softening point lower than 145°C, the polyester being formed by mixing a dicarboxylic acid component, a diol component and at least one crosslinking component selected from a polyfunctional carboxylic acid component having a trivalency or a higher valency and a polyhydric alcohol component having a trivalency or a higher valency at a mixing ratio represented by the following formula (1), reacting the mixture at a reaction ratio represented by the following formula (2) and subjecting the esterification product to polycondensation and crosslinking.
0.8 ≦ R ≦ 1 + 5a (1)
0.7 ≦ P ≦ [R/(1 + a)]1/2 (2)
wherein R is the ratio of the mole number of the total alcohol components to the mole number of the total acid components, a is the ratio of the sum of the mole number of the polyvalent carboxylic acid component and the mole number of the polyhydric alcohol component to the mole number of the total acid components, and P is the conversion of the carboxylic acid components.
A toner comprising this crosslinked polyester as the binder has an excellent offset-preventing property, low-temperature fixing property and blocking resistance and good charging characteristics with a high moisture resistance, and gives a copied image having good sharpness and image density.
本发明公开了一种用于墨粉的交联聚酯及其制造工艺,其中聚酯的酸值为 5 至 20 mgKOH/g,流动指数为 0.1×10-⁴至300×10-⁴毫升/秒,软化点低于145℃,该聚酯是通过将二羧酸组分、二元醇组分和至少一种交联组分按下式(1)表示的混合比混合而形成的,该交联组分选自具有三价或更高价的多官能团羧酸组分和具有三价或更高价的多元醇组分、以下式(2)表示的反应比对混合物进行反应,并将酯化产物进行缩聚和交联。
0.8 ≦ R ≦ 1 + 5a (1)
0.7 ≦ P ≦ [R/(1 + a)]1/2 (2)
其中,R 是总醇组分摩尔数与总酸组分摩尔数之比,a 是多价羧酸组分摩尔数与多元醇组分摩尔数之和与总酸组分摩尔数之比,P 是羧酸组分的转化率。
以这种交联聚酯为粘合剂的墨粉具有极佳的胶印防止性能、低温固着性能和抗阻塞性能,以及良好的充电特性和较高的防潮性能,复制的图像具有良好的清晰度和图像密度。