# US 8,541,068 B2 · Process for producing an amorphous carbon film > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,541,068 B2 - Document ID: US8541068B2 - Status: Granted - Kind: B2 - Application number: 11/887,704 - Filed: 2006-03-27 - Published: 2009-05-14 - Granted: 2013-09-24 - Earliest claimed: 2005-03-30 - Assignees: Kabushiki Kaisha Toyota Jidoshokki; Ehime Univeristy - Applicants: Hitotoshi Murase; Toshihisa Shimo; Shinfuku Nomura; Hiromichi Toyota; Hiroshi Yamashita; Makoto Kuramoto - Inventors: Hitotoshi Murase; Toshihisa Shimo; Shinfuku Nomura; Hiromichi Toyota; Hiroshi Yamashita; Makoto Kuramoto - Web page: https://patentgrep.com/patent/US8541068B2 ## CPC - C23C 16/26: Deposition of carbon only - B01J 19/088: {giving rise to electric discharges (for heating purposes H05B7/00; for the production of ozone C01B13/11, H01T19/00)} - H05H 1/247: {using discharges in liquid media} - H05H 1/46: using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/26 takes precedence) - B01J 2219/0809: employing two or more electrodes - B01J 2219/083: cylindrical - B01J 2219/0877: Liquid - H05H 1/466: {using capacitive coupling means, e.g. electrodes} - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - H05H: PLASMA TECHNIQUE (apparatus or processes specially adapted for producing X-rays H05G2/00); PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS ## Abstract The process for producing an amorphous carbon film of the present invention is a process for producing an amorphous carbon film comprising contacting a surface of a substrate S with bubbles B which have been formed in a liquid L containing an organic compound and inside which plasma has been generated, so as to form an amorphous carbon film on the surface of the substrate S, and the liquid L contains one or more selected from phenols and alcohols having a carbon number of from 1 to 12. According to the present invention, a hard amorphous carbon film can be formed easily. ## Claims ### Claim 1 A process for producing a thin, high hardness amorphous carbon film, comprising: generating bubbles in a salt-free liquid containing an organic compound while radiating electromagnetic waves continuously from an electrode disposed in the salt-free liquid to the bubbles so as to generate plasma inside the bubbles, wherein the salt-free liquid is an aqueous solution comprising water as a solvent and the organic compound comprises one or more selected from the lower monohydric alcohols having a carbon number of from 1 to 3 as a solute; moving the plasma within the bubbles through the salt-free liquid from the electrode to a substrate disposed in the salt-free liquid; contacting a surface of the substrate with the bubbles, so as to form an amorphous carbon film on the surface of the substrate, the formed amorphous carbon film having a thickness from 0.5 μm to 8 μm and a hardness of 11 GPa or more; and regulating the weight ratio of solute:solvent within a range from 10:90 to 50:50 so as to adjust the rate of forming the amorphous carbon film to deposit a film of the desired thickness and hardness. ### Claim 2 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein pressure is reduced at least at a start of the generation of the bubbles and the plasma and the generation of the bubbles and the plasma is started under 1 to 600 hPa. ### Claim 3 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein pressure is reduced at least at a start of the generation of the bubbles and the plasma, and thereafter the bubbles and the plasma are generated under normal pressure. ### Claim 4 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein the amorphous carbon film has a hardness of 13 GPa or more. ### Claim 5 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein the liquid contains one or more other organic compounds from hydrocarbons and silicone oil. ### Claim 6 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein the substrate is selected from the group consisting of metal, ceramic, resin, paper and wood. ### Claim 7 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein the step of contacting a surface of a substrate with the bubbles so as to form an amorphous carbon film on the surface of the substrate comprises positioning the substrate in the salt-free liquid above the generated plasma bubbles, allowing the plasma bubbles to rise in the salt-free liquid towards the substrate, and contacting the plasma bubbles with the surface of the substrate so as to deposit the amorphous carbon film on the surface of the substrate. ### Claim 8 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein the electromagnetic waves and the bubbles are generated by a plasma generating electrode. ### Claim 9 (depends on 8) A process for producing a thin, high hardness amorphous carbon film recited in claim 8, wherein the distance between the substrate and the plasma generating electrode is between 0.5 and 50 mm. ### Claim 10 (depends on 8) A process for producing a thin, high hardness amorphous carbon film recited in claim 8, wherein the plasma generating electrode has a sharp-pointed or curved side positioned in the direction of the substrate. ### Claim 11 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein the plasma generating electrode comprises aluminum alloy. ### Claim 12 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein the organic compound has a kinematic viscosity of 100 mm2/sec or less. ### Claim 13 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein the organic compound comprises methanol. ### Claim 14 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein the amorphous carbon film has a thickness from 0.5 μm to 8 μm. ### Claim 15 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein the amorphous carbon film has a thickness from 0.5 μm to 2 μm. ### Claim 16 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein the amorphous carbon film has a hardness of 11 GPa or more. ### Claim 17 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein the bubbles contact the surface of the substrate for from 15 to 30 seconds. ### Claim 18 (depends on 1) A process for producing a thin, high hardness amorphous carbon film recited in claim 1, wherein the weight ratio of solute:solvent is from 10:90 to less than 50:50.