Electrophotographic toner and contact development method using the toner

(19)

(11)

EP 0 747 774 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	16.04.1997 Bulletin 1997/16

(43)	Date of publication A2:
	11.12.1996 Bulletin 1996/50

(21)	Application number: 96304293.2

(22)	Date of filing: 07.06.1996

(51)	International Patent Classification (IPC)⁶: G03G 9/087

(84)	Designated Contracting States:
	CH DE FR GB IT LI

(30)

Priority:

07.06.1995 JP 140803/95

(71)	Applicant: MITA INDUSTRIAL CO. LTD.
	Osaka 540 (JP)

(72)	Inventors:
	Inoue, Kazushige Chuo-ku, Osaka-shi, Osaka 540 (JP) Takatsuna, Toru Chuo-ku, Osaka-shi, Osaka 540 (JP) Mori, Yukihiro Chuo-ku, Osaka-shi, Osaka 540 (JP) Nakagawa, Etsuro Chuo-ku, Osaka-shi, Osaka 540 (JP) Higuchi, Hiroko Chuo-ku, Osaka-shi, Osaka 540 (JP)

(74)	Representative: W.P. THOMPSON & CO.
	Eastcheap House Central Approach Letchworth, Hertfordshire SG6 3DS Letchworth, Hertfordshire SG6 3DS (GB)

(54)	Electrophotographic toner and contact development method using the toner

(57) An electrophotographic toner comprises a polyester resin and an electric charge control resin have a functional group which enables the toner to be positively charged. The polyester resin has an acid value of not more than 10 mgKOH/g and a hydroxyl value of not more than 40 mgKOH/g, and the functional group is present in a proportion of 2 to 5 mol % in the electric charge control resin. The invention also concerns a contact development method using this toner with a single-layer positive charge type organic photoconductor to visualise an electrostatic latent image as a toner image.

Search report