Electrophotographic photoreceptor, and image forming device and electrophotographic photoreceptor cartridge using the same member cartridge

An electrophotographic photoreceptor comprising at least a photosensitive layer on an electroconductive support, wherein

• said photosensitive layer comprises a layer including a polyester resin comprising a repeating structural unit represented by the formula (1) and a charge transport material, and
• said charge transport material comprises only a charge transport material containing substantially no unsaturated bond other than in an aromatic ring:
• wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may be substituted, X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms.

An electrophotographic photoreceptor comprising at least a photosensitive layer on an electroconductive support, wherein

• said photosensitive layer comprises a polyester resin containing an antioxidant and having a repeating structural unit represented by the formula (1):
• wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may be substituted, X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms.

An electrophotographic photoreceptor of a positive charge type comprising a monolayer type photosensitive layer on an electroconductive support, wherein said monolayer type photosensitive layer comprises a polyester resin comprising a repeating structural unit represented by the formula (1):

• wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may be substituted, X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms.

An image forming device comprising at least an electrophotographic photoreceptor and a toner, wherein

• the photosensitive layer of said electrophotographic photoreceptor comprises a polyester resin containing a repeating structural unit represented by formula (1) below, and
• the average degree of circularity of said toner, measured by a flow particle image analyzer, is 0.940 or larger and 1.000 or smaller:
• wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may have a substituent, X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms.

An electrophotographic photoreceptor for an image forming device of which an exposure part for forming an electrostatic latent image emits a monochromatic light having an exposure wavelength of 380 nm to 500 nm,

• the photoreceptor comprising at least a photosensitive layer which comprises a polyester resin comprising a repeating structural unit represented by the formula (1):
• wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may be substituted, X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms.

An electrophotographic photoreceptor comprising at least a photosensitive layer on an electroconductive support, said photosensitive layer comprises a charge transport layer,

• wherein said charge transport layer has a transmittance of 70% or larger in the wavelength region of 400 nm to 500 nm, and
• said charge transport layer comprises a polyester resin, said polyester resin comprises a repeating structural unit represented by the formula (1):
• wherein Ar1 to Ar4 each represents, independently of each other, an arylene group which may be substitued, X1 represents a bivalent group or a single bond, and X2 represents a bivalent group with 3 or less atoms.