申请人:TOKAI RUBBER INDUSTRIES, LTD.
公开号:EP0982335A1
公开(公告)日:2000-03-01
A conductive roll to be used as a developing roll, a charging roll, a transfer roll or the like in an electrophotographic apparatus such as a copying machine, a printer or a facsimile, of the present invention comprises a base rubber layer formed on a peripheral surface of a shaft, an intermediate layer formed on a peripheral surface of the base rubber layer, and a surface layer formed on a peripheral surface of the intermediate layer, the surface layer being composed of a resin composition comprising:
(A) a silicone-grafted acrylic polymer which comprises repeating units represented by the following general formula (1), wherein an acrylic polymer portion of the silicone-grafted acrylic polymer exclusive of a structural portion derived from a siloxane has a glass-transition temperature of -35 to 30°C:-(Y)k- -(Z)n- (wherein Y is a structural portion derived from an acrylic monomer; Z is a structural portion derived from the acrylic monomer, which has a graft portion derived from a siloxane; k is a positive number of 1 to 3,000; and n is a positive number of 1 to 3,000); and
(B) an isocyanate curing agent.
According to the present invention, the use of the component (B) enhances the cross-linking of the silicone-component (B) enhances the cross-linking of the silicone-grafted acrylic polymer (A), and thus the surface layer of the conductive roll has an appropriately cross-linked state, so that the conductive roll can be obtained which is superior both in smear resistance and in toner filming resistance.
本发明的导电辊可用作复印机、打印机或传真机等电子照相设备中的显影辊、充电辊、转印辊或类似设备,它包括形成在轴外周表面上的基体橡胶层、形成在基体橡胶层外周表面上的中间层以及形成在中间层外周表面上的表层,表层由树脂组合物构成,树脂组合物包括:
(A) 有机硅接枝的丙烯酸聚合物,该聚合物由以下通式(1)表示的重复单元组成,其中有机硅接枝丙烯酸聚合物的丙烯酸聚合物部分(不包括硅氧烷衍生的结构部分)的玻璃化转变温度为-35 至 30°C:-(Y)k--(Z)n-(其中 Y 是源自丙烯酸单体的结构部分;Z 是源自丙烯酸单体的结构部分,该丙烯酸单体具有源自硅氧烷的接枝部分;k 是 1 至 3,000 的正数;n 是 1 至 3,000 的正数);以及
(B) 异氰酸酯固化剂。
根据本发明,使用组分(B)可增强有机硅组分(B)的交联,增强有机硅接枝丙烯酸聚合物(A)的交联,从而使导电辊的表层具有适当的交联状态,这样就可以获得抗涂抹性和抗墨粉成膜性都很出色的导电辊。