EP-4530753-B1 - FIXING DEVICE AND IMAGE FORMING APPARATUS

EP4530753B1EP 4530753 B1EP4530753 B1EP 4530753B1EP-4530753-B1

Inventors

OMORI, KENJI
OHARA, HIDEAKI
YOSHIKAWA, RYOHEI

Dates

Publication Date: 20260506
Application Date: 20240425

Claims (13)

A fixing device (28) comprising: a first rotatable member (30); a second rotatable member (40) disposed in contact with the first rotatable member; a pressing member (50) that is disposed along an inner circumferential surface of the second rotatable member and presses the inner circumferential surface of the second rotatable member such that the second rotatable member is pressed against the first rotatable member; a sliding member (60) interposed between the inner circumferential surface of the second rotatable member and the pressing member; and a lubricant interposed between the inner circumferential surface of the second rotatable member and the sliding member, wherein the inner circumferential surface of the second rotatable member contains a resin having a siloxane group, and, wherein the lubricant contains an oil having a siloxane group in a main chain, characterized in that : the resin of the inner circumferential surface of the second rotatable member further contains an electrically conducting material treated with siloxane; wherein a sliding surface of the sliding member contains a resin having a siloxane group and an electrically conducting material treated with siloxane.
The fixing device according to claim 1, wherein the electrically conducting material contained in the inner circumferential surface of the second rotatable member and/or the electrically conducting material contained in the sliding surface of the sliding member is carbon black.
The fixing device according to claim 1 or 2, wherein the content of the electrically conducting material contained in a layer forming the inner circumferential surface of the second rotatable member with respect to 100 parts by mass of a resin contained in the layer forming the inner circumferential surface of the second rotatable member is 5 parts by mass or more.
The fixing device according to claim 3, wherein the content of the electrically conducting material contained in the layer forming the inner circumferential surface of the second rotatable member with respect to 100 parts by mass of the resin contained in the layer forming the inner circumferential surface of the second rotatable member is 10 parts by mass or more and 50 parts by mass or less.
The fixing device according to any one of claims 1 to 4, wherein the resin having a siloxane group and contained in the inner circumferential surface of the second rotatable member and/or the resin having a siloxane group and contained in the sliding surface of the sliding member is at least one of a siloxane-modified polyimide resin and a siloxane-modified polyamide-imide resin.
The fixing device according to any one of claims 1 to 5, wherein the inner circumferential surface of the second rotatable member has a surface resistivity of 1.0 × 10 7 Ω/square or less.
The fixing device according to any one of claims 1 to 6, wherein the sliding surface of the sliding member has a surface resistivity of 1.0 × 10 7 Ω/square or less.
The fixing device according to any one of claims 1 to 7, wherein the resin having a siloxane group and contained in the inner circumferential surface of the second rotatable member and/or the resin having a siloxane group and contained in the sliding surface of the sliding member is resin particles.
The fixing device according to claim 8, wherein the sliding surface of the sliding member contains a heat-resistant thermoplastic resin, the resin particles of the resin having a siloxane group, and the electrically conducting material treated with siloxane.
The fixing device according to claim 9, wherein the resin particles are thermosetting silicone resin particles.
The fixing device according to claim 8, wherein the inner circumferential surface of the second rotatable member contains the resin particles of the resin having a siloxane group, the electrically conducting material treated with siloxane, and at least one resin selected from the group consisting of a polyimide resin, a polyamide-imide resin, a polyether ether ketone resin, and a polyphenylene sulfide resin.
The fixing device according to claim 11, wherein the resin particles are thermosetting silicone resin particles.
An image forming apparatus (100) comprising: an image holding member (1); a latent image forming device (2, 3) that forms a latent image on a surface of the image holding member; a developing device (4) that develops the latent image using a developer to form a toner image; a transfer device (5) that transfers the developed toner image onto a recording medium (P); and the fixing device (28) according to any one of claims 1 to 12, the fixing device fixing the toner image to the recording medium.

Description

Background (i) Technical Field The present disclosure relates to a fixing device and an image forming apparatus. (ii) Related Art For example, Japanese Unexamined Patent Application Publication No. 2021-124559 discloses a "belt including a resin layer containing a polyimide and a siloxane-modified resin and disposed at least as an outermost layer configured to slide along a sliding member, wherein the molar ratio of the siloxane structure in the siloxane-modified resin is 20% by mole or more." The preamble of claim 1 relates to features seen in this prior art document. Japanese Unexamined Patent Application Publication No. 11-219036 discloses a "transfer member used for an image forming method including transferring a toner image formed on an electrostatic latent image carrier onto the transfer member, heating and pressurizing the transfer member on which a recording medium is placed, cooling the transfer member, and separating the recording medium from the transfer member to thereby transfer and fix the toner image to the recording medium, wherein the transfer member includes a rubber layer having a uniform thickness and a siloxane-modified polyimide layer that are disposed in this order on a substrate." Japanese Patent No. 5147998 discloses a "multilayer tubular endless film including a surface layer, an elastic layer, and a base layer, wherein all the layers are seamless, wherein the surface layer is formed by centrifugal forming, wherein the material of the surface layer is at least one selected from the group consisting of fluorocarbon rubbers, fluorocarbon resins, siloxane-modified polyimides, and urethane rubbers, wherein the surface layer has a surface roughness (Rz) of 0.25 to 1.5 µm, wherein the base layer is formed by centrifugal forming, and wherein the material of the base layer is a polyimide or a polyamide-imide." Summary One previously known fixing device includes: a first rotatable member; a second rotatable member disposed in contact with the first rotatable member, a pressing member that is disposed along an inner circumferential surface of the second rotatable member and presses the inner circumferential surface of the second rotatable member such that the second rotatable member is pressed against the first rotatable member; a sliding member interposed between the inner circumferential surface of the second rotatable member and the pressing member; and a lubricant interposed between the inner circumferential surface of the second rotatable member and the sliding member (this fixing device may be hereinafter referred to also as a specific fixing device). Accordingly, it is an object of the present disclosure to provide a fixing device having both better slidability and a higher charge suppression ability than a specific fixing device in which the inner circumferential surface of the second rotatable member is formed only of a resin having no siloxane group (e.g., a polyimide resin) and a specific fixing device in which the sliding surface of the sliding member is formed only of a resin having no siloxane group (e.g., a fluorocarbon resin). According to a first aspect of the present disclosure, there is provided a fixing device including: a first rotatable member; a second rotatable member disposed in contact with the first rotatable member; a pressing member that is disposed along an inner circumferential surface of the second rotatable member and presses the inner circumferential surface of the second rotatable member such that the second rotatable member is pressed against the first rotatable member; a sliding member interposed between the inner circumferential surface of the second rotatable member and the pressing member; and a lubricant interposed between the inner circumferential surface of the second rotatable member and the sliding member, wherein the inner circumferential surface of the second rotatable member contains a resin having a siloxane group and an electrically conducting material treated with siloxane, wherein a sliding surface of the sliding member contains a resin having a siloxane group and an electrically conducting material treated with siloxane, and wherein the lubricant contains an oil having a siloxane group in a main chain. According to a second aspect of the present disclosure, in the fixing device according to the first aspect, the electrically conducting material contained in the inner circumferential surface of the second rotatable member and/or the electrically conducting material contained in the sliding surface of the sliding member is carbon black. According to a third aspect of the present disclosure, in the fixing device according to the first or second aspect, the content of the electrically conducting material contained in a layer forming the inner circumferential surface of the second rotatable member with respect to 100 parts by mass of a resin contained in the layer forming the inner circumferential surface of the second rotatable member is 5 pa