# US 9,873,106 B2 · Hydrophilic member, method for manufacturing same and hydrophilic member maintenance method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,873,106 B2 - Document ID: US9873106B2 - Status: Granted - Kind: B2 - Application number: 15/313,200 - Filed: 2015-04-17 - Published: 2017-06-29 - Granted: 2018-01-23 - Earliest claimed: 2014-05-30 - Assignees: Murakami Corporation - Applicants: Murakami Corporation - Inventors: Masatoshi Nakamura; Momoko Takinami; Tomoaki Takinami; Masaaki Matsuura - Web page: https://patentgrep.com/patent/US9873106B2 ## CPC - B01J 21/063: {Titanium; Oxides or hydroxides thereof} - B01J 21/12: Silica and alumina - B01J 35/19: {Catalysts containing parts with different compositions} - B01J 35/39: Photocatalytic properties - B32B 9/00: Layered products comprising a {layer of a} particular substance not covered by groups B32B11/00 - B32B29/00 - B32B 9/005: {comprising one layer of ceramic material, e.g. porcelain, ceramic tile (layered products with at least two ceramic layers composed mainly of ceramic B32B18/00)} - C03C 17/3417: {all coatings being oxide coatings} - C09D 5/008: {Temporary coatings (C09D5/20 takes precedence)} - B01J 35/30: characterised by their physical properties - B01J 35/70: characterised by their crystalline properties, e.g. semi-crystalline (catalysts comprising carbon B01J21/18; molecular sieves B01J29/00) - C03C 2217/71: Photocatalytic coatings - C03C 2217/75: Hydrophilic and oleophilic coatings - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) ## Abstract A hydrophilic member that enables provision of favorable photocatalytic performance while enhancing water repellent agent resistance and a method for manufacturing the same are provided. A maintenance method for removing a water repellent agent adhering to a surface of a hydrophilic layer of a hydrophilic member, the water repellent agent having a cation property, is provided. A photocatalytic layer is formed on a base material. An intermediate layer is formed on the photocatalytic layer. A hydrophilic layer having an isoelectric point exceeding 7 is formed on the intermediate layer. The intermediate layer is a layer that causes the hydrophilic layer to be formed so as to have a low density compared to a case where the hydrophilic layer is formed directly on the photocatalytic layer under the same film forming condition. A water repellent agent adhering to a surface of the hydrophilic layer can effectively be removed using sodium bicarbonate. ## Claims ### Claim 1 A hydrophilic member including a photocatalytic layer disposed on a base material and a hydrophilic layer disposed on the photocatalytic layer, wherein: an isoelectric point of the hydrophilic layer has a value exceeding 7; and a layer is disposed as an intermediate layer between the photocatalytic layer and the hydrophilic layer. ### Claim 2 (depends on 1) The hydrophilic member according to claim 1, wherein the intermediate layer consists essentially of SiO2. ### Claim 3 (depends on 2) The hydrophilic member according to claim 2, wherein a film thickness of the intermediate layer is 5 to 15 nm. ### Claim 4 (depends on 1) The hydrophilic member according to claim 1, wherein the hydrophilic layer consists essentially of Al2O3. ### Claim 5 (depends on 4) The hydrophilic member according to claim 4, wherein the film thickness of the hydrophilic layer is 5 to 13 nm. ### Claim 6 (depends on 1) The hydrophilic member according to claim 1, wherein the photocatalytic layer consists essentially of TiO2. ### Claim 7 A hydrophilic member manufacturing method comprising: forming a photocatalytic layer on a base material; forming an intermediate layer on the photocatalytic layer; and forming a hydrophilic layer having an isoelectric point exceeding 7 on the intermediate layer. ### Claim 8 (depends on 7) The hydrophilic member manufacturing method according to claim 7, wherein: each of the photocatalytic layer, the intermediate layer and the hydrophilic layer is formed by a physical vapor deposition method; and a temperature of the base material when the hydrophilic layer or the intermediate layer is formed is lower than the temperature of the base material when the photocatalytic layer is formed. ### Claim 9 (depends on 1) A hydrophilic member maintenance method comprising performing water repellent agent removal treatment of a surface of the hydrophilic layer of a hydrophilic member according to claim 1, hydrophilicity of the surface being lowered by adherence of a water repellent agent, using sodium bicarbonate to recover the hydrophilicity of the surface of the hydrophilic layer. ### Claim 10 (depends on 9) The maintenance method according to claim 9, wherein the water repellent agent removal treatment is performed by rubbing the surface of the hydrophilic layer with a sponge with sodium bicarbonate and water absorbed therein. ### Claim 11 (depends on 1) The hydrophilic member according to claim 1, wherein the hydrophilic layer is porous. ### Claim 12 (depends on 7) The hydrophilic member according to claim 7, wherein the hydrophilic layer is porous.