# US 9,519,082 B2 · Microscopic roughness structure with protective film and method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,519,082 B2 - Document ID: US9519082B2 - Status: Granted - Kind: B2 - Application number: 14/238,053 - Filed: 2012-08-16 - Published: 2014-07-24 - Granted: 2016-12-13 - Earliest claimed: 2011-08-16 - Assignees: Mitsubishi Rayon Co., Ltd. - Applicants: Tsuyoshi Takihara; Seiichiro Mori; Eiko Okamoto - Inventors: Tsuyoshi Takihara; Seiichiro Mori; Eiko Okamoto - Web page: https://patentgrep.com/patent/US9519082B2 ## CPC - G02B 1/105 - G02B 1/14: Protective coatings, e.g. hard coatings - C09J 5/06: involving heating of the applied adhesive - G02B 1/10: Optical coatings produced by application to, or surface treatment of, optical elements (G02B1/08 takes precedence) - G02B 1/118: having sub-optical wavelength surface structures designed to provide an enhanced transmittance, e.g. moth-eye structures - Y10T 156/10: Methods of surface bonding and/or assembly therefor - Y10T 428/24364: with transparent or protective coating - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract In a protective film affixed to a microscopic roughness structure having a microscopically rough structure on the surface, water contact angle of the surface of the microscopic roughness structure is 40° or less, compressive stress obtainable when the adhesive layer of the protective film is compressed to a compression ratio of 20% is 0.6 MPa to 3.0 MPa; in the infrared absorption spectrum of the surface on the microscopically rough structure side of the microscopic roughness structure, ratio (A1/A2) of peak area A1 having absorption maximum of 3700 cm−1 to 3100 cm−1, and peak area A2 having absorption maximum of 1730±10 cm−1, is 0.1 to 0.8; in the surface of adhesive layer of the protective film, ratio (B1/B2) of peak area B1 having absorption maximum of 3700 cm−1 to 3100 cm−1, and peak area B2 having absorption maximum of 1730±10 cm−1, is 0.6 to 1.3. ## Claims ### Claim 1 A protective film-attached microscopic roughness structure comprising: a microscopic roughness structure on the surface having a microscopically rough structure having a period less than or equal to the wavelength of visible light, and a protective film for protecting the surface of the microscopic roughness structure affixed thereto, wherein the water contact angle of the surface of the microscopic roughness structure is 40° or less, the protective film comprises an adhesive layer that is in contact with the surface on the microscopically rough structure side, and the compressive stress obtainable when the adhesive layer is compressed in the thickness direction to a compression ratio of 20% is 0.6 MPa to 3.0 MPa, wherein the adhesive layer of the protective film is affixed to the entire surface of the microscopic roughness structure without extending beyond the surface of the microscopic roughness structure. ### Claim 2 A protective film-attached microscopic roughness structure comprising: a microscopic roughness structure on the surface having a microscopically rough structure having a period less than or equal to the wavelength of visible light, and a protective film for protecting the surface of the microscopic roughness structure affixed thereto, wherein the protective film comprises an adhesive layer that is in contact with the surface on the microscopically rough structure side; in the infrared absorption spectrum of the surface of the microscopically rough structure, the ratio (A1/A2) of the peak area A1 having the absorption maximum in the region of 3700 cm−1 to 3100 cm−1, and the peak area A2 having the absorption maximum in the region of 1730±10 cm−1, is 0.1 to 0.8; and in the infrared absorption spectrum of the surface of the adhesive layer, the ratio (B1/B2) of the peak area B1 having the absorption maximum in the region of 3700 cm−1 to 3100 cm−1, and the peak area B2 having the absorption maximum in the region of 1730±10 cm−1, is 0.6 to 1.3, wherein the adhesive layer of the protective film is affixed to the entire surface of the microscopic roughness structure extending beyond the surface of the microscopic roughness structure. ### Claim 3 (depends on 1) The protective film-attached microscopic roughness structure according to claim 1, wherein in the infrared absorption spectrum of the surface of the adhesive layer, the ratio (B1/B2) of the peak area B1 having the absorption maximum in the region of 3700 cm−1 to 3100 cm−1, and the peak area B2 having the absorption maximum in the region of 1730±10 cm−1, is 0.6 to 1.3. ### Claim 4 (depends on 1) The protective film-attached microscopic roughness structure according to claim 1, wherein in the infrared absorption spectrum of the surface of the microscopically rough structure, the ratio (A1/A2) of the peak area A1 having the absorption maximum in the region of 3700 cm−1 to 3100 cm−1, and the peak area A2 having the absorption maximum in the region of 1730±10 cm−1, is 0.1 to 0.8. ### Claim 5 (depends on 1) The protective film-attached microscopic roughness structure according to claim 1, wherein the storage elastic modulus E of the adhesive layer is in the range of 1×106 Pa to 6×106 Pa at least any one temperature in the range of 10° C. to 60° C. ### Claim 6 (depends on 2) The protective film-attached microscopic roughness structure according to claim 2, wherein in the adhesive layer, the storage elastic modulus E has a rubbery plateau in the range of 1.5×106 Pa or greater. ### Claim 7 (depends on 1) A method for producing the protective film-attached microscopic roughness structure according to claim 1, the method comprising heating the adhesive layer, and affixing the protective film to the surface of the microscopic roughness structure. ### Claim 8 (depends on 7) The method for producing the protective film-attached microscopic roughness structure according to claim 7, wherein the protective film is affixed to the surface of the microscopic roughness structure while the storage elastic modulus E of the adhesive layer is adjusted to 6×106 Pa or less. ### Claim 9 (depends on 5) The protective film-attached microscopic roughness structure according to claim 5, wherein in the adhesive layer, the storage elastic modulus E has a rubbery plateau in the range of 1.5×106 Pa or greater. ### Claim 10 (depends on 2) A method for producing the protective film-attached microscopic roughness structure according to claim 2, the method comprising heating the adhesive layer, and affixing the protective film to the surface of the microscopic roughness structure. ### Claim 11 (depends on 10) The method for producing the protective film-attached microscopic roughness structure according to claim 10, wherein the protective film is affixed to the surface of the microscopic roughness structure while the storage elastic modulus E of the adhesive layer is adjusted to 6×106 Pa or less. ### Claim 12 (depends on 1) The protective film-attached microscopic roughness structure according to claim 1, wherein the adhesive layer comprises any one of the compounds selected from the group consisting of cyclohexanedimethanol monoacrylate, 2-hydroxypropyl acrylate, and polypropylene glycol monoacrylate. ### Claim 13 (depends on 2) The protective film-attached microscopic roughness structure according to claim 2, wherein the adhesive layer comprises any one of the compounds selected from the group consisting of cyclohexanedimethanol monoacrylate, 2-hydroxypropyl acrylate, and polypropylene glycol monoacrylate.