Mitsubishi Chemical Corporation

Akiteru Fujii

Yuuta Kumano

Satoshi Kato

Teruyuki Mitsumori

Mamoru Nozomi

Yuka Nagao

Atsushi Yoshizawa

Mitsuo Wada

Kazutaka Ida

Wataru Miyashita

Takayuki Shouda

Tetsuo Murayama

Shinichi Suzuki

Tadashi Mizushima

Chiyoko Sato

Takayuki Shoda

Rui Zhao

Mitsuru Yoneyama

Mikiko Sato

An electrophotographic photoreceptor that includes a conductive support; and at least a charge generation layer and a charge transport layer on the conductive support, where the charge transport layer includes at least two layers of a first charge transport layer which is an outermost layer and a second charge transport layer which is in contact with the first charge transport layer, such that the elastic deformation ratio of a binder resin A contained in the first charge transport layer is T1(%) and the elastic deformation ratio of a binder resin B contained in the second charge transport layer is T2(%) such that T1 and T2 satisfy a relationship of {0&#x2264;(T1&#x2212;T2)&#x2264;4}, the first charge transport layer contains a charge transport material &#x3b1; having a molecular weight of 600 or more, and the binder resin A and the binder resin B have different monomer units from each other.

Electrophotographic photoreceptor, electrophotographic photoreceptor cartridge and image forming apparatus

The present invention relates to an electrophotographic photoreceptor comprising: a conductive support; and a photosensitive layer on the conductive support, wherein the photosensitive layer contains a charge transport substance, a binder resin, and a compound which has a molecular weight of equal to or less than 350, and is represented by General Formula (1).

Electrophotographic photoreceptor, electrophotographic photoreceptor cartridge, and image forming apparatus

An electrophotographic photoreceptor comprises a conductive support and, at least a photosensitive layer on the conductive support, wherein the photosensitive layer includes a polyarylate resin and the polyarylate resin has a repeating structure represented by formula (1), and the amount of bisphenol residues represented by formula (3) after the polyarylate resin is hydrolyzed, is 0.2% to 1%, in terms of intensity ratio, based on the total amount of bisphenol residues represented by formula (2) and formula (3) after the polyarylate resin is hydrolyzed, the bisphenol residues being detected with a gas chromatograph employing a hydrogen flame ionization detector (FID).

Electrophotographic photoreceptor, electrophotographic photoreceptor cartridge, image forming apparatus, and polyarylate resin

Provided is a lamination-type electrophotographic photoreceptor comprising a conductive substrate, and a charge transport layer and a charge generation layer both on the conductive substrate, wherein the charge transport layer comprises a charge transport substance represented by the general formula (1), a binder resin, and a particulate silicon compound.

Coating liquid for electrophotographic photoreceptor production, electrophotographic photoreceptor, and image formation apparatus

The invention relates to a multilayer type electrophotographic photoreceptor comprising: a conductive support; and, on the conductive support, a charge generation layer containing a hydroxygallium phthalocyanine pigment and a charge transport layer, wherein the content of &#x3b1;-chloronaphthalene in hydroxygallium phthalocyanine pigment in the charge generation layer is in a range of 0 ng/cmto 0.1 ng/cm, the charge transport layer contains a non-halogen organic solvent having a boiling point of 140&#xb0; C. or more, and the content of the non-halogen organic solvent having a boiling point of 140&#xb0; C. or more is in a range of 0.1 &#x3bc;g/cmto 5 &#x3bc;g/cm.

The invention provides an image forming apparatus and an electrophotographic photoreceptor, comprising: a conductive support; and at least a charge generation layer and a charge transport layer on the conductive support, wherein said charge generation layer contains a hydroxygallium phthalocyanine synthesized using a halogen solvent, said charge transport layer contains a polyester resin having a specific structural unit, and said charge transport layer is formed using a non-halogen solvent.

Electrophotographic photoreceptor and image forming apparatus

The invention is to provide an image forming apparatus and an electrophotographic cartridge, which are free from problems of cleaning failure, filming, soiling, residual images (ghosts), fogging, density reduction, noise and the like and which can provide high-definition images even when a toner having a small particle size and having a high degree of circularity is used and even when a photoreceptor having a small outer diameter is used. An image forming apparatus comprising: an electrophotographic photoreceptor containing a conductive support and a photosensitive layer on the conductive support, a charging unit for charging the electrophotographic photoreceptor, an imagewise exposing unit for imagewise exposing the charged electrophotographic photoreceptor to form an electrostatic latent image thereon, a developing unit for developing the electrostatic latent image with a toner, and a transferring unit for transferring the toner from the electrophotographic photoreceptor to a receiving unit, wherein the outer diameter of the electrophotographic photoreceptor is 20 mm or less, the photosensitive layer contains a polyarylate resin, and the toner satisfies the specific requirements (1) and (2).

Image forming apparatus and electrophotographic cartridge

The present invention relates to an electrophotographic photoreceptor comprising a conductive support and at least a photosensitive layer provided thereon, wherein the electrophotographic photoreceptor comprises an outermost layer which contains a specific charge transport substance and a specific compound.

An electrophotographic photoreceptor, an electrophotographic photoreceptor cartridge, and an image forming apparatus, which are excellent in electrical characteristics such as a responsivity and at the same time, excellent in the crack resistance, are provided. Two kinds of charge transport substances each having a specific structure and a polyester resin having a specific structure are combined, whereby the crack resistance can be improved.

An electrophotographic photoreceptor, an electrophotographic photoreceptor cartridge, and an image forming apparatus, which are excellent in electrical characteristics such as a responsivity and at the same time, excellent in the crack resistance, are provided. Two kinds of charge transport substances each having a specific structure and a polycarbonate resin having a specific structure are combined, whereby the electrical characteristics such as responsivity and the crack resistance can be improved at the same time.

The invention provides a laminate-type electrophotographic photoreceptor for use in a negative charge system, comprising a conductive support, and a photosensitive layer containing a charge generation layer and a charge transport layer, on the conductive support, wherein in addition to a fluorene compound and a diamine compound which are responsible for charge transport, a compound having a specific structure is used in combination.

The invention can provide an electrophotographic photoreceptor comprising a photosensitive layer containing a specific charge transport material and a specific copolymerized polycarbonate resin, and an image-forming apparatus and an electrophotographic cartridge which use the electrophotographic photoreceptor.

Electrophotographic photoreceptor, image-forming apparatus, and electrophotographic cartridge

When an abutting pressure of the cleaning blade on a photoreceptor is increased, a chattering occurs due to the so-called a stick-slip phenomenon that the blade repeatedly undergoes sticking to the outermost surface of the photoreceptor and slipping thereon. As a result, a possibility of noise generation becomes higher and there is a possibility that toner particles might pass through during slipping to cause a cleaning failure, resulting in a streaky image defect. There is also a higher possibility that the so-called a filming phenomenon might occur, in which a component of the toner sticks to the photoreceptor surface by the action of the blade pressure and becomes difficult to remove, so as to lead to persistent image defects. Furthermore, since the photoreceptor is rotated with toners in the state of being strongly pressed thereagainst, the image defects are apt to be caused due to peripheral-direction scratches. An electrophotographic photoreceptor is provided in which the outermost layer of the photoreceptor contains a specific charge-transporting material and a specific binder resin.

A phthalocyanine composite with high sensitivity and low environmental dependence is provided. It comprises both at least one phthalocyanine compound expressed by general formula (1) and at least one phthalocyanine compound expressed by general formula (2):  where, in the general formulae (1) and (2), Mrepresents at least one arbitrary atom or atomic group that is capable of binding to a phthalocyanine, Mrepresents an atom, or an atomic group containing an atom, selected from the second and subsequent periods of the periodic table and capable of binding to a phthalocyanine, Mand Mbeing different in kind from each other, X-Xrepresent, independently of each other, a halogen atom, and a, b, c, and d represent, independently of each other, an integer between 0 and 4 and satisfy a+b+c+d&#x2267;1.

Phthalocyanine composition and photoconductive material, electrophotographic photoreceptor cartridge, and image-forming apparatus each employing the composition

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Kanagawa, Japan

Akiteru Fujii