Abstract:
PROBLEM TO BE SOLVED: To provide a two-component developer having a long life of a toner and good stirrability and stably charging the toner, to provide a developing device using the two-component developer, and to provide an image forming apparatus and an image forming method. SOLUTION: The two-component developer 1 includes a toner 3 and a resin coated carrier 2. The toner 3 includes: a toner core particle formed by aggregating polyester resin particles dispersed in an aqueous solution with a polyvalent metal salt; and a coating layer formed by coating the toner core particle surface with a carboxylate-containing polyester resin by aggregation and converting the carboxylate contained in the polyester resin into the corresponding carboxylic acid. The resin coated carrier 2 includes: a carrier core material 2a having an apparent density of ≤2.0 g/cm 3 , a residual magnetization of ≤10 emu/g and a volume average particle size of 25-50 μm; and a resin coating layer 2b formed on the carrier core material 2a surface. An image is formed using the two-component developer 1. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a method for producing a low density resin-coated carrier having a small resin amount to a carrier core material and having a uniform resin coating layer formed on the carrier core material. SOLUTION: A resin-coated carrier 2 includes a carrier core material 2a and a resin coating layer 2b formed on the surface of the carrier core material 2a. The carrier core material 2a includes pores and an apparent density of 1.6-2.0 g/cm 3 and a remanent magnetization of 10 emu/g or less. The resin coating layer 2b is formed by a dry process of making resin particles adhere to the surface of the carrier core material 2a and applying heat and impact force to the resin particles. A volume average particle size of the resin particles is less than 1 μm. A two-component developer 1 containing the resin-coated carrier 2 is charged in a developing device in an image forming apparatus, and an image is formed. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To solve the following problems: in an environment in which a two-component developer is subjected to thermal and mechanical stress with time and in the main unit of a copying machine, fluidity of the developer deteriorates significantly and density unevenness of an output image occurs; and in printing on many sheets, the fluidity of the developer deteriorates, density unevenness due to insufficient conveyance occurs and an obtained output image degrades significantly. SOLUTION: There is provided an electrophotographic two-component developer satisfying an expression (1): 10.4≤log((C/B)/(A×T))≤17.9, wherein A represents the wax material content (wt.%) of a toner therein; T represents toner concentration (wt.%) of the two-component developer; B represents volume resistance (Ωcm) of a carrier core material; and C represents a volume resistance (Ωcm) of a carrier. COPYRIGHT: (C)2010,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a carrier capable of improving stability of charging amount of toner and capable of maintaining high quality image formation for a long period of time. SOLUTION: The carrier 1 includes a cover layer 3 on the surface of core material 2, wherein a shape factor (SF-1) of the core material 2 is ≥119, a proportion of the shape factor of the core material after forming the cover layer 3 to the shape factor of the core material 2 is in the range of ≥90% to ≤100%, a bridge resistance value upon agitation test is lowered by a change amount in the range of 0 to ≤1/10 with respect to the initial value under an electric field of 1,000 V/cm and, as the result, the high quality image formation can be maintained over a long period of time. COPYRIGHT: (C)2010,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a two-component developer having good transfer efficiency and capable of stably charging a toner for a long period of time, and to provide an image forming method.SOLUTION: The two-component developer contains a toner and a resin-coated carrier. The toner includes a plurality of kinds of external additives having different average primary particle diameters from one another, externally added to the toner. In the plurality of kinds of external additives, at least one kind of additive has an average primary particle diameter of 0.1 μm or more. The resin-coated carrier comprises a carrier core material made of a ferrite having a volume average particle diameter of 25 μm or more and 90 μm or less and a resin coating layer formed on the surface of the carrier core material, the layer containing a silicone resin and magnetic fine particles having a volume average particle diameter of 0.1 μm or more and 2 μm or less, and the layer containing the magnetic fine particles by 40 parts by weight or more and 100 parts by weight or less with respect to 100 parts by weight of the silicone resin.
Abstract:
PROBLEM TO BE SOLVED: To provide a resin coated carrier where a charge control agent is distributed uniformly in a resin coated layer and toner is stably charged for a long time, and a method of manufacturing the resin coated carrier. SOLUTION: This resin coated carrier includes a carrier core material and a resin coated layer formed on the surface of the carrier core material. The resin coated layer contains charge control agent carrying particles carrying the charge control agent in a plurality of holes of porous inorganic fine particles having the holes. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a resin-coated carrier capable of stably charging a toner by preventing the thickness of a resin coating layer that is formed on a surface of the carrier core from becoming nonuniform. SOLUTION: The resin-coated carrier 50 includes a carrier core 51 and a resin coating layer 52, formed on the surface of the carrier core 51. The carrier core 51 is composed of a porous material, having fine pores 51a formed on a surface thereof, and has an apparent density of 1.6-2.0 g/cm 3 . The resin coating layer 52 contains cross-linked fine resin particles 53. Additionally, the resin-coated carrier 50 is configured, such that a volume average particle size of the cross-linked fine resin particles 53 contained in the resin coating layer 52 and the area average diameter of the surface fine pores 51a satisfy a predetermined relational expression. COPYRIGHT: (C)2011,JPO&INPIT
Abstract translation:要解决的问题:通过防止形成在载体芯的表面上的树脂涂层的厚度变得不均匀来提供能够稳定地对调色剂充电的树脂涂布载体。 解决方案:树脂涂覆载体50包括形成在载体芯51的表面上的载体芯51和树脂涂层52.载体芯51由多孔材料构成,具有形成在 其表面,并且具有1.6-2.0g / cm 3的表观密度。 树脂被覆层52含有交联的树脂微粒53.此外,树脂被覆载体50构成为使树脂被覆层52中包含的交联性微粒子树脂53的体积平均粒径和 表面细孔51a的面积平均直径满足规定的关系式。 版权所有(C)2011,JPO&INPIT