# US 11,906,925 B2 · Cleaner rollers and cleaning electrophotographic photoconductors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,906,925 B2 - Document ID: US11906925B2 - Status: Granted - Kind: B2 - Application number: 17/913,381 - Filed: 2020-04-08 - Published: 2023-05-11 - Granted: 2024-02-20 - Earliest claimed: 2020-04-08 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Hewlett-Packard Development Company, L.P. - Inventors: Bin Huang; Minedys Macias Guzman; Daniel C. Tanchangco - Web page: https://patentgrep.com/patent/US11906925B2 ## CPC - G03G 21/0058: {using a roller or a polygonal rotating cleaning member; Details thereof, e.g. surface structure (G03G21/0064 takes precedence)} - G03G 21/0088: {removing liquid developer} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract Herein is described a liquid electrophotographic a printing apparatus comprising: a photoconductor; a liquid electrophotographic ink developer unit for applying liquid electrophotographic ink to the photoconductor; a cleaner roller contactable with the photoconductor, the cleaner roller comprising an open-celled foam material having thereon a coating comprising abrasive particles and a binder. Also described herein is a cleaner roller for cleaning a liquid electrophotographic printing apparatus' photoconductor and a method of operating a liquid electrophotographic printing apparatus using a cleaner roller described herein. ## Claims ### Claim 1 A liquid electrophotographic printing apparatus, comprising: a photoconductor; a liquid electrophotographic ink developer unit for applying liquid electrophotographic ink to the photoconductor; and a cleaner roller contactable with the photoconductor, wherein the cleaner roller comprises an open-celled foam material and a coating on the open-celled foam material, the coating comprising abrasive particles and a binder formed from polymerization of an isocyanate. ### Claim 2 (depends on 1) The liquid electrophotographic printing apparatus according to claim 1, wherein the isocyanate is or comprises an aromatic or aliphatic isocyanate. ### Claim 3 (depends on 2) The liquid electrophotographic printing apparatus according to claim 2, wherein the binder is formed from the polymerization of the isocyanate with a polyol. ### Claim 4 (depends on 3) The liquid electrophotographic printing apparatus according to claim 3, wherein the polyol is selected from the group consisting of a polycarbonate polyol and a polyester polyol. ### Claim 5 (depends on 3) The liquid electrophotographic printing apparatus according to claim 3, wherein the polyol is a polycarbonate diol of the formula HO—[—R1—O—(C═O)—O—R2—]m—OH, wherein R1 and R2 are each independently a group of the formula —(CH2)n—, and wherein n is 3 to 8 and m is 1 or more. ### Claim 6 (depends on 5) The liquid electrophotographic printing apparatus according to claim 5, wherein the polyol has a number average molecular weight of from 200 to 6000. ### Claim 7 (depends on 1) The liquid electrophotographic printing apparatus according to claim 1, wherein the abrasive particles are selected from the group consisting of alumina (Al2O3) particles, BN particles, SiC particles, ZrO2 particles, SiO2 particles, TiO2 particles, and CaCO3 particles. ### Claim 8 (depends on 7) The liquid electrophotographic printing apparatus according to claim 7, wherein the abrasive particles are alumina (Al3O3) particles and wherein the alumina (Al3O3) particles have an aspect ratio of from 2:1 to 10:1. ### Claim 9 (depends on 7) The liquid electrophotographic printing apparatus according to claim 7, wherein the abrasive particles are alumina (Al3O3) particles and wherein the alumina (Al3O3) particles have a mean particle size of from 0.1 microns to 10 microns. ### Claim 10 (depends on 1) The liquid electrophotographic printing apparatus according to claim 1, wherein a wt:wt ratio of the binder to the abrasive particles is from 20:80 to 80:20. ### Claim 11 (depends on 1) The liquid electrophotographic printing apparatus according to claim 1, wherein the open-celled foam material is selected from the group consisting of a polyurethane foam, a polyester foam, a polypropylene foam, a polyethylene foam, a polyurethane silicone foam, and a polyether polyurethane foam. ### Claim 12 (depends on 1) The liquid electrophotographic printing apparatus according to claim 1, wherein the binder is formed from the polymerization of the isocyanate in the absence of a polyol. ### Claim 13 (depends on 1) The liquid electrophotographic printing apparatus according to claim 1, wherein the coating further comprises an additive selected from the group consisting of a solvent, a wetting agent, a catalyst, and combinations thereof. ### Claim 14 A cleaner roller for cleaning a photoconductor of a liquid electrophotographic printing, the cleaner roller comprising an open-celled foam material and a coating on the open-celled foam material, the coating comprising abrasive particles and a binder formed from polymerization of an isocyanate and a polyol. ### Claim 15 (depends on 14) The cleaner roller according to claim 14, wherein the isocyanate is an aromatic isocyanate, the polyol is polycarbonate polyol, and the abrasive particles comprise alumina particles having a mean particle size of from 0.1 microns to 10 microns. ### Claim 16 A method of operating a liquid electrophotographic printing apparatus, the method comprising: applying a liquid electrophotographic ink to a photoconductor having a latent electrostatic image thereon to form a developed image comprising the liquid electrophotographic ink; transferring the developed image, in reversed form, to an intermediate transfer member or a print medium in contact with the photoconductor; and cleaning excess electrophotographic ink or components of the electrophotographic ink from the photoconductor by contacting the photoconductor with a cleaner roller, wherein the cleaner roller comprises an open-celled foam material and a coating on the open-celled foam material, the coating comprising abrasive particles and a binder formed from polymerization of an isocyanate. ### Claim 17 (depends on 16) The method according to claim 16, wherein a cleaner fluid is applied to the photoconductor from the cleaner roller or another roller.