The present invention provides a negataively chargeable charge controlling agent to control a charged state of a powder or granular material such as toner for electrophotography, where the agent comprises a polyhydroxyalkanoate having at least one kind of 3-hydroxy-ω-carboxyalkanoic acid unit represented by the chemical formula (1):
wherein n is an integer selected from 1 to 8; R
1
is an H, Na or K atom, or
and when more than one unit exists, n and R
1
is the same or different between the units. The charge controlling agent is excellent in electrophtographic properties and propitious to environment because of the biodegradability of the polyhydroxyalkanoate.
wherein n is an integer selected from the range shown in the same chemical formula; R
1
is an H atom, Na atom, K atom, or
and when more than one unit exists, n and R
1
may differ from unit to unit.
本发明提供了一种可负电荷的电荷控制剂,用于控制粉末或颗粒材料(如用于电子照相的墨粉)的带电状态,其中该电荷控制剂包括一种聚羟基烷酸酯,该聚羟基烷酸酯具有至少一种由
化学式(1)表示的3-羟基-ω-羧基烷酸单元:
其中 n 是选自 1 至 8 的整数; R
1
是 H、Na 或 K 原子,或
当存在多个单元时,n 和 R
1
相同或不同。由于聚羟基烷酸酯具有
生物降解性,因此电荷控制剂具有优异的电泳特性和环保性。
其中 n 是选自同一
化学式所示范围的整数;R
1
是 H 原子、Na 原子、K 原子,或
当存在一个以上的单元时,n 和 R
1
可能因单元而异。