| 摘要 |
PURPOSE:To form a sharp image superior in powder characteristics by executing an operation for removing a part of surfactant adhered to produced microcapsules and reducing an amt. of surfactant to a specified percentage or less of the total weight of the capsulated toner. CONSTITUTION:A surfactant used in a step for producing microcapsules in an aq. medium tends to adhere to the produced microcapsules in a considerable amt. The capsulated toner obtained by separating them in an adhered state from the aq. medium and drying them scarcely obtain satisfactory powder characteristics, and their electric resistance and chargeability are readily affected by environmental conditions, such as temp. and humidity. The capsulated toner superior in the powder characteristics, etc. are obtained by lowering an amt. of surfactant to <=1wt%. To produce the capsulated toner small in an amt. of surfactant adhered to them, it is desirable to wash the produced microcapsules once or in several times with a solvent, such as water, and remove them adhered to the surfaces of the outer shells to an extent as small as possible, and then to subject them to a drying treatment, such as spray drying. |
