Ricoh Company, Ltd.

Yuka Aoyama

Yohta Sakon

Masanobu Gondoh

Masahiro Ohmori

Shohei Gohda

Kaori Toyama

Shinji Nohsho

Keiichiro Juri

Hiromi Sakaguchi

Yuta Nakamura

Shinya Nakayama

Hiroshi Yamada

Yasuyuki Yamashita

Yuuki Mizutani

Satoshi Kojima

Yoshihiro Moriya

An image forming apparatus including an image bearer and a cleaning blade is provided. The cleaning blade comprises an elastic member configured to contact a surface of the image bearer to remove toner particles remaining thereon. The elastic member comprises a substrate and a surface layer comprising a cured product of a curable composition and a siloxane compound. The surface layer is disposed on at least a part of a lower surface of the substrate. The surface layer has a hardness gradient in which a Martens hardness HM measured using a nanoindenter decreases from a surface of the surface layer toward the lower surface of the substrate in a thickness direction, and the Martens hardness HM measured in a region extending from a vicinity of the surface (with a load of 1 &#x3bc;N) to a deepest part in the thickness direction (with a load of 1,000 &#x3bc;N) ranges from 2.5 to 32.5 N/mm. The toner has a tensile breaking force F of from 200 to 450 gf (from 1.96 to 4.41 N), measured using a powder layer compression/tensile strength measurement device under a load of 32 kgf (313.81 N).

Image forming apparatus, image forming method, and process cartridge

An image forming apparatus including developing unit to develop electrostatic latent image with toner to form visible image, and cleaning unit including elastic member including surface layer and configured to remove the toner, wherein Martens hardness A and Martens hardness B of the surface layer measured by applying load of 1 &#x3bc;N and load of 1,000 &#x3bc;N, respectively, to position of the surface layer in thickness direction thereof using nanoindenter are both 2.5 N/mmor greater but 32.5 N/mmor less, and Martens hardness A and Martens hardness B satisfy inequality,Martens hardness A&#x3e;Martens hardness Bwherein coefficient of dynamic friction of the surface layer against polycarbonate is 0.5 or less, and the toner includes polyester resin insoluble to THF and Tg of THF-insoluble component of the toner determined from DSC curve of first heating of DSC is &#x2212;60&#xb0; C. or higher but 20&#xb0; C. or lower.

Image forming apparatus and image forming method

A cleaning blade includes a support and an elastic member with a flat shape. The elastic member has a secured end secured to the support and a free end. A ridgeline of the free end contacts a cleaning target to remove substances adhering to a surface of the cleaning target. The elastic member includes a base and a surface layer made of a cured product of a curable composition. The surface layer is disposed on at least a part of an opposite face disposed to oppose a downstream side of the cleaning target downstream from a contact portion of the elastic member with the cleaning target in a direction of movement of the cleaning target. A thickness of the surface layer progressively decreases toward the secured end along a cross section perpendicular to a longitudinal direction of the surface layer.

Cleaning blade, process cartridge, and image forming apparatus

A cleaning blade including an elastic member configured to be in contact with a surface of a cleaning-target member to remove deposited matter deposited on the surface of the cleaning-target in member, wherein the elastic member includes a base and a surface layer formed of a cured product of a curable composition, the surface layer is formed on at least part of a bottom surface of the base including a contact part to be in contact with the cleaning-target member, where the bottom surface of the base is a surface of the base facing a downstream side along a traveling direction of the cleaning-target member relative to the contact part, and an average film thickness of the surface layer at the contact part is 10 &#x3bc;m or greater but 100 &#x3bc;m or less.

Provided is a cleaning blade including an elastic member, wherein a spin-spin relaxation time (T) of the elastic member obtained by a solid echo method in a pulse NMR analysis is longer than or equal to 0.60 msec but shorter than or equal to 1.0 msec, and wherein the elastic member has a contact part to contact a surface of a cleaning target member, and the contact part contains a cured product of a curable composition.

Cleaning blade, image forming apparatus, and process cartridge

A cleaning blade includes an elastic member including a contact portion to contact the surface of a member to be cleaned and remove an extraneous matter adhering to the surface of the member. The contact portion includes a modified portion including at least one of an impregnated portion including a first cured material formed of a first curing composition in a thickness direction from the surface of the contact portion; and a surface layer formed of a second curing composition on the surface of the contact portion. The surface of the modified portion has a tack maximum value not greater than 3.0 [gf/mm].

Cleaning blade including modified portion including impregnated portion and surface layer, and process cartridge and image forming apparatus including the cleaning blade

An image forming apparatus is provided which includes an image bearer, a charger to charge the image bearer, a latent image forming device to form an electrostatic latent image on the image bearer, a developing device to develop the electrostatic latent image with a toner, a transfer device to transfer the toner image onto a transfer medium, and a cleaning blade to remove residual toner particles remaining on the image bearer. The toner includes a binder resin and a release agent. The release agent has a longest length Lmax in the toner, which is equal to or greater than 1.1 times a maximum Feret diameter Df of the toner. The cleaning blade includes a strip-like elastic body blade having a contact part with the image bearer. The contact part includes a cured product of an ultraviolet curable composition including an acrylate or methacrylate compound having an alicyclic structure.

Image forming apparatus and process cartridge

A cleaning blade, including: rectangular elastic body blade containing cured first-UV-curable resin at tip ridgeline portion thereof, brought into contact with surface of to-be-cleaned member, the cured first-UV-curable resin being formed by impregnating the tip ridgeline portion with the first-UV-curable resin, followed by curing, and depth of the elastic body blade impregnated with the first-UV-curable resin from edge surface thereof is 50 &#x3bc;m-150 &#x3bc;m, wherein the elastic body blade contains surface layer containing cured second-UV-curable resin at the edge surface, wherein load-displacement curve of Martens hardness thereof has inflection points, and is obtained by pressing region of the surface layer thereof via resin particles having average particle diameter of 5 &#x3bc;m-10 &#x3bc;m, and distance of the region from the tip ridgeline portion is 0.5 mm or less, and wherein ratio of displacement at the inflection point, with which load is maximum, to the average particle diameter is 1.5-2.0.

A cleaning blade cleaning the surface of an object includes a rigid holder; and a strip-shaped elastic body fixed on the holder, having a tip ridgeline to contact the surface of the object. The elastic body has a Martens hardness M1 in the range of from 0.9 to 10.0 N/mmat a position 300 &#x3bc;m from the ridgeline on an undersurface of the elastic body including the ridgeline, a Martens hardness M2 at a position 1,000 &#x3bc;m therefrom and a Martens hardness M3 at a position 2,000 &#x3bc;m therefrom, and M1, M2 and M3 satisfy the following relationship:M1&#x3e;M2&#x3e;M3.

Cleaning blade, image forming apparatus and process cartridge

A cleaning blade includes a supporting member, and a tabular elastic member. One end portion of the elastic member is fixed to the supporting member, and the other end portion is a free end portion whose tip edge is to be contacted with a member to be cleaned while rubbing the surface to remove a residual material therefrom. The tip portion of the free end portion of the elastic member ranging in length from 0 to 500 &#x3bc;m from the tip surface thereof includes at least a cured material of a curable compound and an elastic material of the elastic member. The elastic member satisfies the relationship, 0.05(%)&#x2266;[(t&#x2212;t)/t]&#xd7;100&#x2266;2%, wherein trepresents the maximum thickness of the tip portion of the elastic member, and trepresents the average thickness of the rear portion of the free end portion of the elastic member.

Cleaning blade, and image forming apparatus and process cartridge using the cleaning blade

A cleaning blade cleaning the surface of an object includes a rigid holder; and a strip-shaped elastic body fixed on the holder, including a tip ridgeline to contact the surface of the object. The cleaning blade includes a part having a Martens hardness of from 0.9 to 5.0 N/mmat a depth of 20 &#x3bc;m from an undersurface of the blade including the ridgeline, 0.3 to 0.8 N/mmat a depth of 40 &#x3bc;m therefrom, and the Martens hardness at a depth of 20 &#x3bc;m therefrom larger than that at a depth of 40 &#x3bc;m therefrom by 0.6 N/mm.

Provided is a cleaning blade formed of an elastic blade and configured to abut on the surface of a cleaning target member, which allows a leading end edge portion of the elastic blade to move on the surface thereof, to remove powder from the surface of the cleaning target member. A blade surface of the elastic blade, which has the leading end edge portion of the elastic blade on one side thereof and faces the surface of the cleaning target member, has a Martens hardness of 1.2 N/mmor greater when it is indented by 5 &#x3bc;m at a location that is 20 &#x3bc;m away from the leading end edge portion, a Martens hardness of 1 N/mmor less when it is indented by 20 &#x3bc;m at the location, and an elastic power of 70% or greater when it is indented by 5 &#x3bc;m at the location.

Cleaning blade, and image forming apparatus using same and process cartridge

A cleaning blade, including a strip-shaped elastic blade to contact the surface of a member to be cleaned, traveling on an edge line of the elastic blade, to remove a powder from the surface thereof, wherein the edge line of the elastic blade is impregnated with an ultraviolet curable resin including a fluorinated acrylic monomer, a surface layer harder than the elastic blade is formed on each of an under surface thereof, having the edge line as one line of the under surface and facing the member, and an apical surface thereof, having the edge line as one line of the apical surface and being parallel to a direction of the thickness thereof, and the apical surface is impregnated with the ultraviolet curable resin at a depth of from 50 to 150 &#x3bc;m and the under surface is impregnated therewith at a depth of from 20 to 100 &#x3bc;m.

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Kanagawa, Japan

Yuka Aoyama