Electrophotographic photoreceptor, process cartridge, and image forming apparatus
An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer disposed so as to overlie the conductive substrate and containing a first charge-transporting material having two triphenylamine skeletons and a charge mobility of approximately 4×10 −6 cm 2 /Vs or more and at least one second charge-transporting material selected from the group consisting of a charge-transporting material having one triphenylamine skeleton and a charge mobility of approximately 5×10 −5 cm 2 /Vs or more, a charge-transporting material having two triphenylamine skeletons and being different from the first charge-transporting material, and a charge-transporting material having three triphenylamine skeletons, wherein the second charge-transporting material content is approximately from 0.2 weight % to 1.0 weight % relative to the total charge-transporting material content.
1. An electrophotographic photoreceptor comprising:
a conductive substrate; and
a photosensitive layer disposed so as to overlie the conductive substrate and containing a first charge-transporting material having two triphenylamine skeletons and a charge mobility of approximately 4×10 −6 cm 2 /Vs or more and a second charge-transporting material comprising a charge-transporting material having three triphenylamine skeletons, wherein
the second charge-transporting material content is approximately from 0.2 weight % to 1.0 weight % relative to the total charge-transporting material content.
2. The electrophotographic photoreceptor according to claim 1 , wherein the second charge-transporting material content is approximately from 0.3 weight % to 0.5 weight % relative to the total charge-transporting material content in the photosensitive layer.
3. The electrophotographic photoreceptor according to claim 1 , wherein the photosensitive layer includes a charge-generating layer and a charge-transporting layer that are disposed so as to overlie the conductive substrate in sequence, the charge-transporting layer contains the first charge-transporting material and the second charge-transporting material, and the second charge-transporting material content is approximately from 0.2 weight % to 1.0 weight % relative to the total charge-transporting material content.
4. The electrophotographic photoreceptor according to claim 3 , wherein the second charge-transporting material content is approximately from 0.3 weight % to 0.5 weight % relative to the total charge-transporting material content in the photosensitive layer.
5. The electrophotographic photoreceptor according to claim 1 , wherein the first charge-transporting material is N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine.
6. The electrophotographic photoreceptor according to claim 1 , wherein the second charge-transporting material further comprises a charge-transporting material having two triphenylamine skeletons and being different from the first charge-transporting material, and the charge-transporting material having two triphenylamine skeletons and being different from the first charge-transporting material is a charge-transporting material represented by General Formula (CT2-2)
(where R C21 , R C22 , R C23 , R C21′ , R C22′ , and R C23′ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a formyl group, an alkyl group, an alkoxy group, or an aryl group).
7. The electrophotographic photoreceptor according to claim 1 , wherein the charge-transporting material having three triphenylamine skeletons is selected from the group consisting of a charge-transporting material represented by General Formula (CT2-3) below and a charge-transporting material represented by General Formula (CT2-4) below
[where R C31 , R C32 , R C33 , R C32′ , and R C33′ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a formyl group, an alkyl group, an alkoxy group, or an aryl group]
[where R C41 , R C42 , R C43 , R C41′ , R C41″ , R C42″ , and R C43″ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a formyl group, an alkyl group, an alkoxy group, or an aryl group].
8. A process cartridge comprising the electrophotographic photoreceptor according to claim 1 , wherein
the process cartridge is removably attached to an image forming apparatus.
9. An image forming apparatus comprising:
the electrophotographic photoreceptor according to claim 1 ;
a charging unit that serves to charge the surface of the electrophotographic photoreceptor;
an electrostatic latent image forming unit that serves to form an electrostatic latent image on the charged surface of the electrophotographic photoreceptor;
a developing unit that serves to develop the electrostatic latent image on the surface of the electrophotographic photoreceptor with a developer containing toner to form a toner image; and
a transfer unit that serves to transfer the toner image to the surface of a recording medium.