DEVELOPING DEVICE, ELECTROPHOTOGRAPHIC PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC IMAGE FORMING APPARATUS

• Main Authors: UESUGI TOMOYA, NISHI AKIO, SUGIYAMA RYO, NAGAOKA KAZUTOSHI, NAKAMURA MINORU, YAMAWAKI KENTARO, ISHII TORU
• Format: Patent
• Language: English; Japanese
• Published: 30.04.2021
• Subjects: CHEMISTRY; CINEMATOGRAPHY; COMPOSITIONS BASED THEREON; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; MAGNETOGRAPHY; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PHOTOGRAPHY; PHYSICS; THEIR PREPARATION OR CHEMICAL WORKING-UP

To provide a developing device that prevents chipping and contamination of a surface of a developer carrier and satisfactorily prevents development streaks, ghost, and fogging, even after durable use for a large number of prints in a high-temperature and high-humidity environment.SOLUTION: A developing device comprises a toner and a developer carrier. The developer carrier has a conductive substrate and a single-layer surface layer on the substrate. The surface layer has a matrix including a cross-linked urethane resin as a binder. When the modulus of elasticity of the matrix in a first area 41 from an outer surface to a depth of 0.1 μm measured on a cross section in a thickness direction of the surface layer is E1, and the modulus of elasticity of the matrix in a second area 42 from the outer surface to a depth of 1.0 to 1.1 μm is E2, formulas (1) and (2) are satisfied. The Martens hardness measured in a condition of a maximum load of 2.0×10-4 N is 85 MPa or more and 1100 MPa or less. (1) E1≥200 MPa; (2) 10 MPa≤E2≤100 MPa.SELECTED DRAWING: Figure 5 【課題】高温高湿度環境における、多数枚印刷の耐久使用においても、現像剤担持体表面の削れや汚染が抑制されるとともに、現像スジとゴーストとカブリが良好な現像装置の提供。【解決手段】トナーと、現像剤担持体とを備えた現像装置であって、該現像剤担持体は、導電性の基体とその上の単層の表面層とを有し、表面層は架橋ウレタン樹脂をバインダーとして含むマトリックスを有し、該表面層の厚み方向断面で測定される外表面から深さ０．１μｍまでの第１領域４１における該マトリックスの弾性率をＥ１とし、該外表面から深さ１．０〜１．１μｍまでの第２領域４２における該マトリックスの弾性率をＥ２としたとき、式（１）及び（２）を満たし、最大荷重２．０×１０−４Ｎの条件で測定したマルテンス硬度が、８５ＭＰａ以上１１００ＭＰａ以下であることを特徴とする。Ｅ１≧２００ＭＰａ （１）１０ＭＰａ≦Ｅ２≦１００ＭＰａ （２）【選択図】図５