Bridgestone Corporation

Junji Sakata

Hirotaka Yamazaki

Takahiro Kawagoe

Tadashi Nakajima

Toshio Iwasawa

Kazushige Ebe

Hiroyuki Kanesugi

Takeo Yoshida

Itsumi Komada

Toshihiro Hamaji

Akihito Kimura

Koji Takagi

Hiroyuki Anzai

Hajime Kitano

Hikaru Ishikawa

Shuyou Akama

Takayuki Sugimura

This invention relates to a photo-curing or electron beam-curing adherent resin composition being excellent in the adhesiveness to various adherends such as metal oxide, metal, resin and so on, and more particularly to an adherent resin composition of a photo-curing or electron beam-curing type comprising a difunctional urethane (metha)acrylate oligomer (A) and a monomer component (B), characterized in that the urethane (metha)acrylate oligomer includes a urethane prepolymer portion composed of a polyol and a polyisocyanate wherein repetitive number of urethane prepolymer portion (n) is 10-30, and the monomer component (B) is a cyclic monomer having a (metha)acryloyl group.

Adherent resin composition

A conductive roller such as a developing roller, a charging roller or the like provided with a resin coating layer on a surface of an elastic layer, and more particularly to a conductive roller having the resin coating layer using an ultraviolet-curing type resin or an electron beam curing type resin and being obtained by contriving a structure of the resin coating layer, rendering the resin coating layer to contain microparticles, controlling the particle size of the microparticles, or forming the resin coating layer after the outer peripheral surface of the elastic layer is subjected to surface treatment.

Developing roller, charging roller, conductive roller and method for producing the same

There is provided a conductive elastic roller () comprising a shaft member () and one or more elastic layers () disposed on an outside of the shaft member () in a radial direction, wherein at least one of the elastic layers () is composed of an ultraviolet-curing type resin formed by curing a raw material for the elastic layer comprising a urethane acrylate oligomer (A), a photo-polymerization initiator (B) and a conductive agent (C) through ultraviolet irradiation, and the urethane acrylate oligomer (A) is a urethane acrylate oligomer synthesized by using as a polyol a polyether polyol (a1) having a proportion of primary hydroxyl groups in hydroxyl groups located at molecular ends of not less than 40% obtained by an addition polymerization of propylene oxide to a polyhydric alcohol alone, or the polyether polyol (a1) and another polyol (a2), and provides a conductive elastic roller () provided with an elastic layer having a low hardness, a small compression residual strain and an improved stain resistance to an adjoining member such as Organic Photoconductors or the like.

Conductive elastic roller and image forming apparatus comprising the same

There are disclosed an elastic member which comprises (A) polyurethane foam obtained by agitationally mixing a foaming agent, a foam stabiizer and a urethane prepolymer synthesized from a polyol and a polyisocyanate in the presence of a modified silicone, or (B) polyurethane foam obtained by agitationally mixing a polyol, a polyisocyanate, a modified silicone oil bearing a functional group reactive with a polyisocyanate, a foaming agent and a foam stabiizer comprising a polyether modified silicone containing 50 to 100% by weight of a polyoxyethylene unit in the polyether moiety; image formation equipment equipped with the above elastic member; and a toner supply roller which is composed of a foamed elastic member mounted on a developing apparatus and which has a compression spring constant in the range of 0.25 to 5.0 N/mm and a surface friction resistance in the range of 0.4 to 1.2 N. The elastic member has low surface-friction resistance and uniform fine cells, and is well suited as a member for image formation equipment.

Elastic member and image formation equipment

A foamed elastic member according to the invention comprises an elastic member made of polyurethane foam molded by an in-mold foaming process, and has properly determined physical properties of its surface and/or properly determined shape and arrangement of foam cells opened on the surface. The foamed elastic member is suitably used for a toner feed roller in a developing device for electrically charging toner from a toner storage portion, feeding the toner onto the surface of a photosensitive member and forming a toner image corresponding to an electrostatic latent image on the surface of the photosensitive member. In this case, it exhibits an excellent toner scraping and toner feeding performance, to form an image free from such defect as irregularity in pitch and density, or free from reduction in density.

Foamed elastic member for use in image forming apparatus

There is disclosed an elastic member constituted of polyurethane foam obtained by agitationally mixing with water, a urethane prepolymer synthesized from a polyol and a polyisocyanate, characterized by simultaneously employing as polyols, a (A) polymer polyol synthesized from a polyether polyol as a basis, comprising at least 70% by weight of oxypropylene moiety; and a (B) hydrophilic polyether polyol comprising at least 50% by weight of oxyethylene moiety, or simultaneously employing as polyols, the component (A), the component (B) and a (C) polyether polyol comprising at least 70% by weight of oxypropylene moiety. The above elastic member is simultaneously imparted with excellent characteristics such as low hardness, fine cells, low residual compressive strain, high strength and the like. The polyurethane foam which constitutes the elastic member can be produced by free foaming. The electroconductive elastic member which is produced by using an aqueous dispersion of carbon instead of water is imparted with low electric resistance in addition to the above excellent characteristics.

Electroconductive elastic member, elastic member and image formation equipment

There are disclosed a toner supply roller which is composed of a foamed elastic body, and has a compression spring constant of 0.25 to 5.0 N/mm, and preferably has the number of cells per a length of 25 mm being 50 to 1200 in the foamed elastic layer; a developing apparatus which is equipped with the above toner supply roller and capable of affording images free from defect such as unevenness in pitch, density, etc.; another developing apparatus which is equipped with a toner supply roller and a developing roller, each being electroconductive, and which satisfies the requirement that the electric resistance of the toner supply roller is always lower than that of the developing roller at an impressed voltage of 100V to 500V, thereby enabling formation of satisfactory images by favorable electrification with the toner supply roller due to favorable adsorption of a toner onto the developing roller; and an image formation apparatus equipped with any of the above developing apparatuses.

Toner supply roller and developing apparatus

An electroconductive elastic member including an electroconductive material prepared from a polyurethane foam or polyurethane elastomer using a polyester polyol and a quaternary ammonium salt to impart electroconductivity. The polyurethane foam or polyurethane elastomer can be produced using, as a polyisocyanate component, a hydrogenated product from diphenyl-methane diisocyanate, hexamethylene diisocyanate, or any of various modified diphenylmethane/hexamethylene diisocyanate The elastic member may be used in an electrophotographic apparatus. Thus the member is well suited for producing an elastic roller with intermediate electric resistance in an electrophotographic process.

Electroconductive elastic member and electrophotographic apparatus using

There are disclosed an electroconductive member comprising a high-molecular material, e.g. polyurethane as a matrix and a quaternary ammonium salt of an organic acid, e.g. bis-or-mono(quaternary ammonium) oxalate; and an electrophotographic apparatus which makes use of the electroconductive member, especially in the form of an electroconductive roller as a developing member, image transfer member, etc. The electroconductive member, when used in electrophotographic mechanism, minimizes an increase in electric resistance at the time of normal continuous passage of an electric current and also variation range in the electric resistance between the circumstances of low temperature/humidity and those of high temperature/humidity.

Electroconductiive member and electrophotogrpahic apparatus

A method of molding a foamed product is carried out by using a front and a rear mold for molding a front and a rear portion of the foamed product and a core interposed between the front and rear molds. The method includes steps of pouring or spraying one of foaming stock solutions onto a molding surface of the one mold, arranging the core in the one mold and pouring or spraying the other foaming stock solution onto the core or a molding surface of the other mold. The front and rear molds are closed at a moment when a lapse of time arrives at 30-100% of a rise time of the foaming stock solution later applied. Thereafter the closed molds are maintained in a position where an angle of the closed molds relative to a horizontal plane is within a range between 90.degree. and an angle more than 0.degree.. The front and rear molds are pivotally connected to each other with their one ends by means of a pivot shaft. The core is pivotally supported with its one end by a shaft arranged in parallel to the pivot shaft. The core is formed with a through-hole and said rear mold is provided with a protrusion to be hermetically fitted in the through-hole of the core.

Foam molding method and mold assembly therefor

Molding a foamed product is carried out by using a front and a rear mold for molding a front and a rear portion of the foamed product and a core interposed between the front and rear molds. The front and rear molds are closed at a moment when a lapse of time arrives at 30%-100% of a rise time of the foaming stock solution later applied. Thereafter the closed molds are maintained in a position where an angle of the closed molds relative to a horizontal plane is within a range between 90.degree. and an angle more than 0.degree.. The front and rear molds are pivotally connected to each other with their one ends by means of a pivot shaft. The core is pivotally supported with its one end by a shaft arranged in parallel to the pivot shaft. The core is formed with a through-hole and said rear mold is provided with a protrusion to be hermetically fitted in the through-hole of the core.

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Tokyo, Japan

Junji Sakata