# US 12,222,587 B2 · Method of producing a plastic lens having a coating layer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,222,587 B2 - Document ID: US12222587B2 - Status: Granted - Kind: B2 - Application number: 16/982,725 - Filed: 2019-03-19 - Published: 2021-01-07 - Granted: 2025-02-11 - Earliest claimed: 2018-03-22 - Assignees: Tokuyama Corporation - Applicants: Tokuyama Corporation - Inventors: Junji Takenaka; Junji Momoda; Yoshihiro Asahara; Takashi Tamukai - Web page: https://patentgrep.com/patent/US12222587B2 ## CPC - G02C 7/102: {Photochromic filters} - B05D 3/06: by exposure to radiation (B05D3/02 takes precedence {; plasma treatment B05D3/141}) - B05D 5/065: {having colour interferences or colour shifts or opalescent looking, flip-flop, two tones} - B29D 11/00009: {Production of simple or compound lenses} - B29D 11/00442: {Curing the lens material} - B29D 11/00653: {photochromic} - B29D 11/00865: {Applying coatings; tinting; colouring (printing, marking or copying processes B41M; identification in general G09F3/00; producing decorative effects in general B44C; positioning or marking of lenses B24B13/0055)} - G02B 1/041: {Lenses} - G02B 1/10: Optical coatings produced by application to, or surface treatment of, optical elements (G02B1/08 takes precedence) - G02B 5/23: Photochromic filters - G02C: SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES (trial frames for testing the eyes A61B3/04; goggles or eyeshields not having the same features as spectacles A61F9/00) - B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02) - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A method of producing a plastic lens having a cured coating layer, comprising the steps of: forming an uncured coating layer from a photocurable coating composition comprising at least a) a photochromic compound, b) a radically polymerizable monomer and c) a photopolymerization initiator on one surface of a plastic lens; and irradiating the plastic lens having the uncured coating layer with light from an LED having an emission peak wavelength of 350 nm or more to less than 450 nm from above the outer surface of the uncured coating layer to cure the uncured coating layer. ## Claims ### Claim 1 A method of producing a plastic lens having a cured coating layer, comprising the steps of: forming an uncured coating layer from a photocurable coating composition comprising at least a) a photochromic compound, b) a radically polymerizable monomer and c) a photopolymerization initiator on one surface of a plastic lens; and irradiating the plastic lens having the uncured coating layer with light from an LED having an emission peak wavelength of 350 nm or more to less than 450 nm from above the outer surface of the uncured coating layer to cure the uncured coating layer, wherein the irradiation intensity of light on the outer surface of the uncured coating layer of the plastic lens having the uncured coating layer is 300 mW/cm2 to 1000 mW/cm2 at an emission peak wavelength, wherein the plastic lens has a center part thickness of less than 2 mm and a peripheral part thicker than the center part, wherein the photochromic compound (a) comprises indenonaphthopyran compound having a molar absorptivity at 400 nm of 3,000 L/(mol·cm) or more and an average molar absorptivity at 350 to 450 nm of 3,000 L/(mol·cm) or more. ### Claim 2 (depends on 1) The production method according to claim 1, wherein the half-value width of the emission peak of the LED is less than 30 nm. ### Claim 3 (depends on 1) The production method according to claim 1, wherein the emission angle from an LED irradiation device of light irradiated from the LED is 120° or less. ### Claim 4 (depends on 1) The production method according to claim 1, wherein the irradiation intensity of light on the irradiation surface of the LED is 2 W/cm2 or more at an emission peak wavelength. ### Claim 5 (depends on 1) The production method according to claim 1, wherein the irradiation intensity of light on the outer surface of the uncured coating layer of the plastic lens having the uncured coating layer is 350 mW/cm2 or more to 1000 mW/cm2 or less at an emission peak wavelength. ### Claim 6 (depends on 1) The production method according to claim 1, wherein the plastic lens is a convex lens and the ratio of the minimum irradiation intensity to the maximum irradiation intensity of light on the outer surface of the uncured coating layer of the plastic lens having the uncured coating layer is 70% or more. ### Claim 7 (depends on 1) The production method according to claim 1, wherein the maximum integrated quantity of light on the outer surface of the uncured coating layer of the plastic lens having the uncured coating layer is 2 J/cm2 or more to less than 50 J/cm2. ### Claim 8 (depends on 1) The production method according to claim 1, wherein the curing of the uncured coating layer is carried out at a surface temperature of the coating layer of 100° C. or lower. ### Claim 9 (depends on 1) The production method according to claim 1, wherein the emission peak wavelength of the LED is 370 nm or more to less than 420 nm. ### Claim 10 (depends on 9) The production method according to claim 9, wherein the emission peak wavelength of the LED is 405 nm. ### Claim 11 (depends on 1) The production method according to claim 1, wherein the LED is composed of a combination of at least two LEDs having different emission peak wavelengths. ### Claim 12 (depends on 11) The production method according to claim 11, wherein the at least two LEDs have different emission peak wavelengths of 385 nm and 405 nm. ### Claim 13 (depends on 1) The production method according to claim 1, wherein a distance between the irradiation surface of the LED and the outer surface of the uncured coating layer is 3 cm or more to 14 cm or less. ### Claim 14 (depends on 1) The production method according to claim 1, wherein the plastic lens is a convex lens and the ratio of the minimum irradiation intensity to the maximum irradiation intensity of light on the outer surface of the uncured coating layer of the plastic lens having the uncured coating layer is 95% or more. ### Claim 15 (depends on 1) The production method according to claim 1, wherein the indenonaphthopyran compound has the molar absorptivity at 400 nm of 3,500 to 7,500 L/(mol·cm) and the average molar absorptivity at 350 to 450 nm of 3,500 to 7,500 L/(mol·cm). ### Claim 16 (depends on 1) The production method according to claim 1, wherein the radically polymerizable monomer (b) comprises radically polymerizable monomers having (meth)acryloyl group and/or (meth)acryloyloxy group. ### Claim 17 (depends on 16) The production method according to claim 16, wherein the radically polymerizable monomers having (meth)acryloyl group and/or (meth)acryloyloxy group comprise a monomer having two radically polymerizable groups, and a monomer having at least three radically polymerizable groups. ### Claim 18 (depends on 17) The production method according to claim 17, wherein the amount of the monomer having two radically polymerizable groups is 40 to 70 parts by mass and the amount of the monomer having at least three radically polymerizable groups is 20 to 60 parts by mass. ### Claim 19 (depends on 17) The production method according to claim 17, wherein the photopolymerization initiator (c) comprises at least one of benzoin-based photopolymerization initiators, benzyl ketal-based photopolymerization initiators, α-hydroxyacetophenone-based photopolymerization initiators, α-aminoacetophenone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, oxime ester-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, and titanocene-based photopolymerization initiators.