| abstract |
The invention provides a novel polyester adapted for use in a charge control agent for a toner for an electrophotographic process, having a charge stability, a high charge amount, an improved dispersibility and a biodegradability, and a producing method and an application technology therefore. According to the invention, there is provided polyhydroxyalkanoate comprising at least one unit represented by the following chemical formula in a molecule:n n—(O—CH(—(CH 2 ) m —CH 2 -p-C 6 H 4 —CONH-A 1 SO 2 R 1 )CH 2 CO)—n n(wherein R 1 represents OH, a halogen atom, ONa, OK or OR 1a ; A 1 and R 1a each represents a substituted or unsubstituted aliphatic hydrocarbon structure, a substituted or unsubstituted aromatic cyclic structure or a substituted or unsubstituted heterocyclic structure; m represents an integer selected from a range of 0 to 7; and R 1 , A 1 , R 1a and m have the aforementioned meanings independently for each unit when plural units are present), a charge control agent containing such polyhydroxyalkanoate, a toner utilizing such charge control agent, and an image forming method and an image forming apparatus utilizing such toner. |