Abstract: A blade for an electrophotographic apparatus is provided which is prevented from turning up, achieves wear resistance, and has excellent cleaning properties. The blade is composed of a support member and a blade member formed of a thermosetting polyurethane elastomer, which are joined together. The blade member has a structure in which a nitrogen concentration continuously increases from the inside of a contact part coming into contact with a counterpart member toward the surface of the contact part.

Abstract: A cleaning blade is provided which does not cause contamination of other parts even when being stored for a long period of time in a high temperature and high humidity environment. The cleaning blade is set in an image forming apparatus employing an electrostatic transfer process, including a blade member and a support member to rub and remove residual toner remaining on a photosensitive drum provided to the image forming apparatus, in which the total amount of nitrogen-containing compounds extracted with methanol from the cleaning blade is 12 ?g or less per cm of the cleaning blade in its longitudinal direction.

Abstract: An electrophotographic cleaning blade is provided which is free of blade turning-up coming from both end portions of the blade in its lengthwise direction. The cleaning blade having a blade formed of a polyurethane resin, which is to come into touch with the surface of a photosensitive drum of an electrophotographic apparatus to remove a toner remaining thereon, and a support member which holds the blade. The blade has a polyurethane resin portion having a dynamic hardness of 0.05 mN/?m2 or more and 0.16 mN/?m2 or less and a high-hardness portion having a dynamic hardness 1.3 times or more and 30 times or less the dynamic hardness of the polyurethane resin portion, provided at each end portion of the blade in its lengthwise direction at its part coming into touch with the photosensitive drum.

Abstract: A method for manufacturing a centrifugal casting die includes the steps of supplying a first liquid agent for forming a backup layer to be releasably bonded to an inner surface of a cylindrical die, rotating the die body so that the first liquid agent is uniformly spread over the entirety of the inner surface of the die body, and curing the first liquid agent spread over the entirety of the inner surface of the die body to form the backup layer. A second liquid agent is applied to be bonded to be integral with an inner surface of the backup layer to form a top layer. Then the die body is rotated so that the second liquid agent is uniformly spread over the entirety of the inner surface of the backup layer and cured to form the top layer. The top layer releasably holds a centrifugally casting material supplied to the inner surface thereof.

Abstract: A blade for electrophotographic apparatus which has a blade member formed of a polyurethane resin, wherein the polyurethane resin is a resin produced by using a polyurethane raw-material composition containing at least the following components (A) to (E): (A) a polyisocyanate; (B) a polyol having a number average molecular weight of 2,000 or more and 4,000 or less; (C) a chain extender having a molecular weight of 200 or less: (D) a polyol having a number average molecular weight which is smaller than the number average molecular weight of the component-(B) polyol and is larger than the molecular weight of the component-(C) chain extender; and (E) a urethane curing catalyst.

Abstract: An electrophotographic cleaning blade is provided which is free of blade turning-up coming from both end portions of the blade in its lengthwise direction. The cleaning blade having a blade formed of a polyurethane resin, which is to come into touch with the surface of a photosensitive drum of an electrophotographic apparatus to remove a toner remaining thereon, and a support member which holds the blade. The blade has a polyurethane resin portion having a dynamic hardness of 0.05 mN/?m2 or more and 0.16 mN/?m2 or less and a high-hardness portion having a dynamic hardness 1.3 times or more and 30 times or less the dynamic hardness of the polyurethane resin portion, provided at each end portion of the blade in its lengthwise direction at its part coming into touch with the photosensitive drum.

Abstract: A blade for an electrophotographic apparatus is provided which is prevented from turning up, achieves wear resistance, and has excellent cleaning properties. The blade is composed of a support member and a blade member formed of a thermosetting polyurethane elastomer, which are joined together. The blade member has a structure in which a nitrogen concentration continuously increases from the inside of a contact part coming into contact with a counterpart member toward the surface of the contact part.

Abstract: A cleaning blade is provided which does not cause contamination of other parts even when being stored for a long period of time in a high temperature and high humidity environment. The cleaning blade is set in an image forming apparatus employing an electrostatic transfer process, including a blade member and a support member to rub and remove residual toner remaining on a photosensitive drum provided to the image forming apparatus, in which the total amount of nitrogen-containing compounds extracted with methanol from the cleaning blade is 12 ?g or less per cm of the cleaning blade in its longitudinal direction.

Abstract: A centrifugal casting die according to the present invention includes a cylindrical die body, a backup layer releasably bonded to the inner surface 12b of the die body, and a top layer bonded to be integral to the inner surface of the backup layer, for holding a centrifugally casting material supplied to the inner surface thereof, whereby the centrifugally casting material having a uniform thickness is easily releasable from the centrifugal casting die without using a die-lubricant.

Abstract: A blade for electrophotographic apparatus which has a blade member formed of a polyurethane resin, wherein the polyurethane resin is a resin produced by using a polyurethane raw-material composition containing at least the following components (A) to (E): (A) a polyisocyanate; (B) a polyol having a number average molecular weight of 2,000 or more and 4,000 or less; (C) a chain extender having a molecular weight of 200 or less: (D) a polyol having a number average molecular weight which is smaller than the number average molecular weight of the component-(B) polyol and is larger than the molecular weight of the component-(C) chain extender; and (E) a urethane curing catalyst.

Abstract: A cleaning blade for use in an electrophotographic apparatus, which rubs and eliminates residual toners. The cleaning blade is made up of polyrethane resin sheet controls chipping of a top end of the cleaning blade and reduces an abrasion of a photosensitive drum. The cleaning blade is prepared by mixing and hardening at least a prepolymer, which is obtained from butylene adipate polyester polyol, hexylene adipate polyester polyol and polyisocyanate, and a hardening agent including a low molecular weight polyol and potassium acetate so that a mol ration (&agr; value) of hydroxyl group to isocyanate group becomes not less than 0.7 and not more than 0.9.

Abstract: A centrifugal casting die according to the present invention includes a cylindrical die body, a backup layer releasably bonded to the inner surface 12b of the die body, and a top layer bonded to be integral to the inner surface of the backup layer, for holding a centrifugally casting material supplied to the inner surface thereof, whereby the centrifugally casting material having a uniform thickness is easily releasable from the centrifugal casting die without using a die-lubricant.

Abstract: A cleaning blade mainly has polyurethane resin, which is mainly installed in an electrophotographic apparatus and rubs and eliminates residual toners control chipping of a top end of the cleaning blade and reduces an abrasion of a photosensitive drum. The cleaning blade is prepared by mixing and hardening at least prepolymer which is obtained from butylene adipate polyester polyol, hexylene adipate polyester polyol and polyisocyanate and the hardening agent including low molecular weight polyol and potassium acetate so that a mol ratio (&agr; value) of hydroxyl group to isocyanate group becomes not less than 0.7 and not more than 0.9.