# US 10,871,733 B2 · Belt, intermediate transfer belt, and image forming apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,871,733 B2 - Document ID: US10871733B2 - Status: Granted - Kind: B2 - Application number: 16/590,926 - Filed: 2019-10-02 - Published: 2020-11-12 - Granted: 2020-12-22 - Earliest claimed: 2019-05-10 - Assignees: Fuji Xerox Co., Ltd. - Applicants: Fuji Xerox Co., Ltd. - Inventors: Futoshi Takei; Shigeru Fukuda; Satoya Sugiura; Masato Furukawa; Hiroaki Tanaka - Web page: https://patentgrep.com/patent/US10871733B2 ## CPC - G03G 15/162: {details of the the intermediate support, e.g. chemical composition} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A belt includes a first layer defining an outer peripheral surface of the belt and a second layer arranged adjacent to the first layer. The first and second layers include a polyimide-based resin. The first layer includes carbon black particles. A part of the carbon black particles which are exposed at the outer peripheral surface of the belt have a size of 5 nm or more and 150 nm or less. The area fraction of the part of the carbon black particles which are exposed at the outer peripheral surface of the belt to the outer peripheral surface of the belt is 2% or more and 35% or less. The belt includes 80 or more conducting points per square micrometer and has a volume resistivity of 10 log Ω·cm or more. ## Claims ### Claim 1 A belt comprising: a first layer defining an outer peripheral surface of the belt; and a second layer arranged adjacent to the first layer, the first layer and the second layer including a polyimide-based resin, the first layer including carbon black particles, wherein a part of the carbon black particles which are exposed at the outer peripheral surface of the belt has a size of 5 nm or more and 150 nm or less, an area fraction of the part of the carbon black particles which are exposed at the outer peripheral surface of the belt to the outer peripheral surface of the belt is 2% or more and 35% or less, the belt includes 80 or more conducting points per square micrometer, the belt has a volume resistivity of 10 log Ω·cm or more, and the outer peripheral surface of the belt has a surface roughness Rz of 0.2 μm or less. ### Claim 2 (depends on 1) The belt according to claim 1, wherein the carbon black particles included in the first layer have an average primary particle size of 2 nm or more and 20 nm or less. ### Claim 3 (depends on 1) The belt according to claim 1, wherein an amount of the carbon black particles included in the first layer is 15% by mass or more of a total mass of the first layer. ### Claim 4 (depends on 2) The belt according to claim 2, wherein an amount of the carbon black particles included in the first layer is 15% by mass or more of a total mass of the first layer. ### Claim 5 (depends on 3) The belt according to claim 3, wherein the amount of the carbon black particles included in the first layer is 15% by mass or more and 30% by mass or less of the total mass of the first layer. ### Claim 6 (depends on 4) The belt according to claim 4, wherein the amount of the carbon black particles included in the first layer is 15% by mass or more and 30% by mass or less of the total mass of the first layer. ### Claim 7 (depends on 1) The belt according to claim 1, wherein the polyimide-based resin included in the first layer is a polyamideimide resin. ### Claim 8 (depends on 2) The belt according to claim 2, wherein the polyimide-based resin included in the first layer is a polyamideimide resin. ### Claim 9 (depends on 1) The belt according to claim 1, wherein the outer peripheral surface of the belt has a surface roughness Rz of 0.15 or less. ### Claim 10 (depends on 1) The belt according to claim 1, wherein the outer peripheral surface of the belt has a surface roughness Rz of 0.1 or less. ### Claim 11 (depends on 1) The belt according to claim 1, wherein the second layer includes carbon black particles, and wherein the carbon black particles included in the second layer have an average primary particle size of more than 20 nm and 40 nm or less. ### Claim 12 (depends on 1) The belt according to claim 1, wherein an amount of the carbon black particles included in the second layer is 10% by mass or more and 40% by mass or less of a total mass of the second layer. ### Claim 13 (depends on 12) The belt according to claim 12, wherein the amount of the carbon black particles included in the second layer is 20% by mass or more and 30% by mass or less of the total mass of the second layer. ### Claim 14 (depends on 1) The belt according to claim 1, wherein a ratio of an amount of the carbon black particles included in the first layer to an amount of the carbon black particles included in the second layer is 0.6 or more and 0.8 or less. ### Claim 15 (depends on 1) The belt according to claim 1, wherein the polyimide-based resin included in the second layer is a polyimide resin. ### Claim 16 (depends on 1) The belt according to claim 1, wherein a ratio of a thickness of the first layer to a total thickness of the first layer and the second layer is 3% or more and 25% or less. ### Claim 17 A belt comprising: a first layer defining an outer peripheral surface of the belt; and a second layer arranged adjacent to the first layer, the first layer and the second layer including a polyimide-based resin, the first layer including carbon black particles, wherein a part of the carbon black particles which are exposed at the outer peripheral surface of the belt has a size of 5 nm or more and 150 nm or less, an area fraction of the part of the carbon black particles which are exposed at the outer peripheral surface of the belt to the outer peripheral surface of the belt is 2% or more and 35% or less, the belt includes 80 or more conducting points per square micrometer, the belt has a volume resistivity of 10 log Ω·cm or more, and Formulae (1) and (2) below are satisfied, ρs1≥10.9 log Ω/sq (1) 0<|ρs1−ρs2|≤0.3 (2) where ρs1 represents a surface resistivity of the outer peripheral surface of the belt, and ρs2 represents a surface resistivity of a surface of the belt which is opposite to the outer peripheral surface of the belt. ### Claim 18 A belt comprising: a first layer defining an outer peripheral surface of the belt; and a second layer arranged adjacent to the first layer, the first layer and the second layer including a polyimide-based resin, the first layer including carbon black particles, wherein a part of the carbon black particles which are exposed at the outer peripheral surface of the belt has a size of 5-nm or more and 150 nm or less, an area fraction of the par of the carbon black particles which are exposed at the outer peripheral surface of the belt to the outer peripheral surface of the belt is 2% or more and 35% or less, the belt includes 80 or more conducting points per square micrometer, the belt has a volume resistivity of 10 log Ω·cm or more, and having a folding endurance number of 3,000 or more, the folding endurance number being measured by an MIT test using a clamp having a curvature radius R of 0.38 mm. ### Claim 19 (depends on 1) An intermediate transfer belt comprising the belt according to claim 1. ### Claim 20 (depends on 1) An image forming apparatus comprising the belt according to claim 1.