Method of manufacturing lenses with gradient properties using imbibition techniques

Abstract

A method of making an optical article includes applying an imbibition composition having at least one dye onto at least a portion of at least one imbibition surface (45) of a substrate (20) to form a coated substrate (10). The method further includes irradiating at least a portion of the coated substrate with heat from a heat source (80) to form a thermal gradient across the coated substrate (10) to diffuse the at least one dye into the imbibition surface to form an at least partially imbibition substrate having a dye concentration gradient corresponding to the thermal gradient. The method further includes removing a residual component of the imbibition composition from the at least partially imbibition substrate. The dye concentration gradient forms a gradient pattern when exposed to actinic radiation.

Description

[0001] This application is a divisional application of a Chinese patent application filed on December 23, 2016, with application number 201680091779.X and invention name “Method for manufacturing a lens with gradient properties using imbibition technology”. Technical Field

[0002] The present invention generally relates to methods of making optical articles (e.g., optical lenses), and in particular to methods of making optical lenses having gradient properties using an imbibition technique, wherein an imbibition dye concentration gradient of a diffused imbibition dye forms a gradient pattern on at least a portion of the optical lens when exposed to actinic radiation. The present invention also relates to optical articles having such gradient properties. Background Art

[0003] For optical articles, such as optical lenses, one or more surfaces can be processed to enhance the overall performance and function of optical articles. The example of such processing includes forming one or more coatings on the surface of optical substrates, such as primer coatings, hard coatings, photochromic coatings and / or anti-reflective coatings. One or more coatings can be applied using many known techniques. A kind of technology includes dissolving or dispersing compounds in the surface of substrates, for example, by immersing substrates in a hot solution containing imbibition dyes or by depositing an imbibition composition comprising imbibition dyes on the surface of substrates and transferring the imbibition dyes thermally into substrates to imbibition dyes into substrates. The term "imbibition (imbibition)" or "imbibition (imbibe)" is intended to represent and include the penetration of imbibition dyes into substrates, the absorption of imbibition dyes to solvent-assisted transfers in substrates, gas phase transfers and other such transfer mechanisms.

[0004] It is known in the art to prepare optical articles, wherein the optical article includes gradient properties. Gradient properties on the surface of the optical article, such as gradient tint effects, provide functional advantages in that the optical article typically has a higher color density in a first portion of the lens (e.g., the top of the lens) for improved distance viewing and a lower color density in a second portion of the lens (e.g., the bottom of the lens). Gradient tint effects also add an aesthetic effect for fashion and style.

[0005] Many different technologies can be used to realize the gradient properties on the optical product surface. In some instances, a part of the optical substrate can be immersed in the liquid coating composition. After the optical substrate is pulled out from the liquid coating composition, the liquid coating composition forms a coating on the immersed surface of the optical substrate. This process requires accurate and reproducible processing, and its degree is higher than the required degree of solid toning (tinting) or painted (coloring). Although methods have been developed to overcome these processing difficulties, such methods usually require additional manufacturing steps, thus increasing additional manufacturing costs. Therefore, the art needs to produce new and improved methods for optical products with gradient properties. Summary of the invention

[0006] In view of the current needs in the art, it is desirable to develop new methods for producing optical articles using imbibition technology to provide gradient properties to the optical articles. It is also desirable to provide cost-effective methods for preparing optical articles, wherein gradient properties can be formed on at least one surface of the optical article in a controlled and predetermined manner.

[0007] The method of preparing an optical article may include applying an imbibition composition having at least one dye to at least a portion of at least one imbibible surface of a substrate to form a coated substrate. The method may also include irradiating at least a portion of the coated substrate with heat from a heat source to form a thermal gradient across the coated substrate to diffuse at least one dye into the imbibible surface to form an at least partially imbibible substrate having a dye concentration gradient corresponding to the thermal gradient. The method may also include removing residual components of the imbibition composition from the at least partially imbibible substrate. The dye concentration gradient may form a gradient pattern when exposed to actinic radiation.

[0008] The permeable surface can be the surface of a permeable substrate. In other examples, the permeable surface can be the surface of a permeable layer located on an optical article. In other examples, the permeable layer can be disposed on a permeable substrate. The thermal gradient can be changed by increasing or decreasing the heat output of a heat source, by increasing or decreasing the distance between the substrate and the heat source, by increasing or decreasing the angle between the substrate and the heat source, and / or by increasing or decreasing the time that the substrate is exposed to heat from the heat source. The center portion of the heat source can be offset relative to the center portion of the substrate. The permeable composition can be applied by a method selected from spin coating, spray coating, inkjet coating, curtain coating or dip coating. The heat source can be selected from an infrared heat source, a convection heat source and a microwave heat source. The heat source can be curved.

[0009] The at least one dye may be selected from fixed hue dyes, photochromic dyes, dichroic dyes and photochromic dichroic dyes. The substrate may be an anisotropic imbibition substrate, and the imbibition composition may include at least one dichroic dye so that at least a portion of the imbibition substrate has a polarization gradient pattern. In other examples, the substrate may be an anisotropic imbibition substrate, and the imbibition composition may have at least one photochromic dichroic dye so that at least a portion of the imbibition substrate has a photochromic polarization gradient pattern when exposed to actinic radiation. The imbibition composition may also include at least one of an ultraviolet light absorber composition, an antioxidant composition, hydroxypropyl cellulose, a hindered amine light stabilizer, a kinetic enhancement additive and a solvent.

[0010] These and other features and characteristics of the method of manufacturing an optical article described herein will become more apparent upon consideration of the following description and appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It should be expressly understood, however, that the drawings are for illustration and description purposes only. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a representative perspective view of an optical article according to some embodiments of the present invention;

[0012] Figure 2 is a top view of an optical article having a gradient pattern on a top surface of the optical article according to some embodiments of the present invention;

[0013] Figure 3 is a representative side view of a coating apparatus for applying one or more coatings to an optical article.

[0014] Figure 4 is a representative side view of a heat source for irradiating at least a portion of a coated optical article according to one embodiment of the present invention; and

[0015] Figure 5 is a representative side view of a heat source for irradiating at least a portion of a coated optical article according to another embodiment of the present invention;

[0016] exist Figure 1-5 , like characters denote like components unless otherwise specified. DETAILED DESCRIPTION

[0017] As used herein, the singular form "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0018] As used herein, spatial or directional terms, such as "left", "right", "upper", "lower", "inner", "outer", "above", "below", etc., refer to various features as shown in the accompanying drawings. However, it should be understood that various alternative orientations may be assumed, and therefore, these terms should not be regarded as limiting.

[0019] Unless otherwise specified, all ranges or ratios disclosed herein should be understood to include any and all subranges or subratios contained therein. For example, a specified range or ratio of "1 to 10" should be considered to include any and all subranges (including endpoints) between a minimum value of 1 and a maximum value of 10; that is, all subranges or subratios start with a minimum value of 1 or greater and end with a maximum value of 10 or less, such as, but not limited to, 1 to 6.1, 3.5 to 7.8, and 5.5 to 10.

[0020] Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about".

[0021] As used herein, the term "substantially parallel" means the relative angle between two objects (e.g., elongated objects and including a reference line) (if extended to a theoretical intersection point) is between 0° and 5°, or between 0° and 3°, or between 0° and 2°, or between 0° and 1°, or between 0° and 0.5°, or between 0° and 0.25°, or between 0° and 0.1°, including the recited values.

[0022] All documents mentioned herein (such as but not limited to published patents and patent applications) are considered to be "incorporated by reference in their entirety" unless otherwise noted.

[0023] As used herein, the term "optical" refers to or relating to light and / or vision. For example, according to various non-limiting examples disclosed herein, the optical element, article or device can be selected from ophthalmic elements, articles and devices; display elements, articles and devices; goggles; windows; and mirrors.

[0024] As used herein, the term "ophthalmic" means pertaining to or relating to the eye and vision. Non-limiting examples of ophthalmic articles or elements include corrective and non-corrective lenses, including single-vision or multi-vision lenses, which may be segmented or non-segmented multi-vision lenses (such as, but not limited to, bifocal lenses, trifocal lenses, and progressive lenses), and other elements used to correct, protect, or enhance (cosmetically or otherwise) vision, including, but not limited to, contact lenses, intraocular lenses, magnifying lenses, and protective lenses or goggles.

[0025] As used herein, the term "substrate" or "optical substrate" refers to lenses, partially formed lenses, and lens blanks.

[0026] As used herein, the term "heat" refers to energy applied to an article or object by conductive, convective and / or radiative means to increase or decrease the temperature of the article relative to the temperature of its surroundings, or to cause the temperature of a first portion of an article to increase or decrease relative to a second portion of the article.

[0027] As used herein, the term "gradient" refers to the measure of the variation in light-affected area on the surface of an article.

[0028] As used herein, the term "imbibition" refers to the process of diffusing or penetrating a dye material into a host material or coating by heat-assisted transfer, etc. The term "imbibition dye" refers to a dye material capable of diffusing or penetrating into a host material or coating by heat-assisted transfer, etc.

[0029] As used herein, the term "coating" refers to a supported film derived from a flowable composition, which may or may not have a uniform thickness, and specifically excludes polymer sheets.

[0030] As used herein, the term "photochromic" and like terms refer to having an absorption spectrum of at least visible radiation that changes in response to the absorption of at least actinic radiation. In addition, as used herein, the term "photochromic material" refers to any substance suitable for exhibiting photochromic properties (i.e., suitable for having an absorption spectrum of at least visible radiation that changes in response to the absorption of at least actinic radiation) and comprising at least one photochromic compound.

[0031] As used herein, the term "dichroic" refers to the ability to absorb one of two orthogonal plane-polarized components of at least transmitted radiation more strongly than the other.

[0032] As used herein, the term "photochromic-dichroic" refers to a material that exhibits both photochromic and dichroic properties in response to at least actinic radiation. For example, the photochromic-dichroic material can be adapted to reversibly switch from a first optically transparent non-polarized state in at least the visible spectrum to a second colored polarized state in at least the visible spectrum in response to at least actinic radiation.

[0033] As used herein to modify the term "state", the terms "first" and "second" are not intended to refer to any particular order or chronology, but rather to refer to two different conditions or properties. For non-limiting illustrative purposes, the first state and the second state of the photochromic compound of the photochromic layer may differ in at least one optical property, such as, but not limited to, absorption of visible light and / or UV radiation. Thus, according to various non-limiting examples disclosed herein, the photochromic compound of the photochromic layer may have a different absorption spectrum in each of the first and second states. For example, although not limited herein, the photochromic compound of the photochromic layer may be transparent in the first state and colored in the second state. Alternatively, the photochromic compound of the photochromic layer may have a first color in the first state and a second color in the second state.

[0034] As used herein, the term "hue" in terms specifically refers to a pure color, such as "green," "red," or "magenta," and includes mixtures of two pure colors, such as "red-yellow" (i.e., "orange"), or "yellow-green." As used herein, the term "color density" refers to the optical density of an optical element surface area printed with a colorant composition when exposed to actinic radiation. Higher color densities result in lower percent light transmittance. For purposes of the present invention, the bottom of the lens is closest to the cheekbone of the lens wearer, and the top of the lens is closest to the forehead of the lens wearer. This linear gradient color pattern should be distinguished from radial gradient color patterns known in the art, for example, color patterns used in conjunction with lenses in which the color density varies radially outward from the center point of the lens to the outer periphery.

[0035] Optical products

[0036] The present disclosure generally relates to optical articles 10. The optical article 10 may be selected from ophthalmic articles or elements, display articles or elements, eye shields, windows, mirrors, active liquid crystal cell articles or elements, and passive liquid crystal cell articles or elements. Examples of ophthalmic articles or elements include, but are not limited to, corrective and non-corrective lenses, including single-vision lenses or multi-vision lenses, which may be segmented or non-segmented multi-vision lenses (such as but not limited to bifocal lenses, trifocal lenses, and progressive lenses), and other elements for correcting, protecting, or enhancing (cosmetically or otherwise) vision, including but not limited to contact lenses, intraocular lenses, magnifying lenses, and protective lenses or goggles. Examples of display articles, elements, and devices include, but are not limited to, screens, monitors, and security elements, including but not limited to security markings and authentication markings. Examples of windows include, but are not limited to, automotive and aircraft transparencies, filters, shutters, and optical switches.

[0037] refer to Figure 1, optical article 10 has a front or top surface 12, a back or bottom surface 14, and a side surface 16 extending between top surface 12 and bottom surface 14. When optical article 10 is an ophthalmic lens, bottom surface 14 is opposite to the eye of the individual wearing optical article 10, side surface 16 is generally located within a support frame, and top surface 12 faces incident light (not shown), at least a portion of which passes through optical article 10 and enters the eye of the individual. In some examples, at least one of top surface 12, bottom surface 14, and side surface 16 can have a variety of shapes, including but not limited to round, flat, cylindrical, spherical, planar, substantially planar, plano-concave and / or plano-convex, and curved, including but not limited to convex and / or concave.

[0038] The optical article 10 has an optical substrate 20, wherein one or more coatings or compositions are deposited on at least one surface of the optical substrate 20, formed on at least one surface of the optical substrate 20, or imbibed into at least one surface of the optical substrate 20. The optical substrate 20 can be made of various materials, including but not limited to organic materials, inorganic materials, or combinations thereof (e.g., composite materials). In some examples, the optical substrate 20 can be an optical or ophthalmic substrate. At least a portion of the optical substrate 20 can have at least one imbibition surface. The phrase "imbibition surface" refers to a physical surface of the optical substrate 20 and / or a coating surface deposited on the optical substrate 20, which is capable of diffusing or penetrating a dye material into the physical surface of the optical substrate 20 by heat-assisted transfer, and / or a coating surface deposited on the optical substrate 20. As described herein, the coating applied to at least a portion of the optical substrate 20 can be at least one coating or composition applied to at least a portion of at least one major imbibition surface of the optical substrate 20. At least one coating or composition can also be applied to the entire imbibition surface of the optical substrate 20. As used herein, the term "coating" refers to a supported film derived from a flowable composition, which may or may not have a uniform thickness.

[0039] The optical article 10 may include any optical substrate known in the art. The substrate may include a polymeric organic material selected from the group consisting of a thermosetting polymeric organic material, a thermoplastic polymeric organic material, or a mixture of such polymeric organic materials. The polymeric organic material may be selected from the group consisting of poly(methacrylic acid C1-C 12alkyl esters), poly(oxyalkylene dimethacrylates), poly(alkoxylated phenol methacrylates), cellulose acetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinylidene chloride), thermoplastic polycarbonates, polyesters, polyurethanes, polythiocarbamates, polysulfi thiourethane), poly(urea-urethane), poly(ethylene terephthalate), polystyrene, poly(α-methylstyrene), co-poly(styrene-methyl methacrylate), co-poly(styrene-acrylonitrile), polyvinyl butyral, or a polymer prepared from: bis(allyl carbonate) monomer, multifunctional acrylate monomer, multifunctional methacrylate monomer, diethylene glycol dimethacrylate monomer, diisopropenylbenzene monomer, ethoxylated bisphenol A dimethacrylate monomer, ethylene glycol dimethacrylate monomer, poly(ethylene glycol) dimethacrylate monomer, ethoxylated phenol dimethacrylate monomer, alkoxylated polyol polyacrylate monomer, styrene monomer, urethane acrylate monomer, glycidyl acrylate monomer, glycidyl methacrylate monomer, diallylidene pentaerythritol monomer, or a mixture of these monomers.

[0040] Substrates suitable for preparing optical articles 10 of the present invention typically have a refractive index of at least 1.55 and may include non-plastic substrates such as glass. More often, substrates commonly used in optical applications are used, including polyol (allyl carbonate) monomers, such as allyl diglycol carbonate, such as diethylene glycol bis (allyl carbonate), which is sold by PPG Industries, Inc. under the registered trademark CR-39; poly (urea) urethane polymers, which are prepared, for example, by the reaction of a polyurethane prepolymer and a diamine curing agent, and one such polymer composition is sold by PPG Industries, Inc. ies, Inc. under the registered trademark TRIVEX; polyol (meth)acryloyl terminated carbonate monomers; diethylene glycol dimethacrylate monomers; ethoxylated phenol methacrylate monomers; diisopropenylbenzene monomers; ethoxylated trimethylolpropane triacrylate monomers; ethylene glycol dimethacrylate monomers; poly(ethylene glycol) dimethacrylate monomers; urethane acrylate monomers; poly(ethoxylated bisphenol A dimethacrylate); poly(vinyl acetate); poly(vinyl alcohol); poly(vinyl chloride); poly(vinylidene chloride); polyethylene; polypropylene; polyurethane; polythiocarbamate; thermoplastic polycarbonates, such as carbonate-linked resins derived from bisphenol A and phosgene, one such material being sold under the registered trademark LEXAN by Sabic Global Technologies; polyesters, such as those sold under the registered trademark MYLAR by Dupont Teij in Films; poly(ethylene terephthalate); polyvinyl butyral; poly(methyl methacrylate), such as those sold by Arkema France Corporation under the registered trademark PLEXIGLAS sold materials, and by making a multifunctional isocyanate and a polymer prepared by reacting a polythiol or polyepisulfide monomer, which is homopolymerized or copolymerized and / or trimerized with a polythiol, a polyisocyanate, a polyisothiocyanate and optionally an ethylenically unsaturated monomer or a vinyl monomer containing a halogenated aromatic group. Copolymers of such monomers and blends of the polymers and copolymers with other polymers are also contemplated, for example, to form an interpenetrating network product.

[0041] Imbibition composition

[0042] As described herein, the method of the present invention includes applying an imbibition composition having at least one imbibition dye to at least one surface of an optical substrate 20. Imbibition of dyes into the imbibible surface of the substrate may include the following steps: applying an imbibition composition to at least a portion of the imbibible substrate, the imbibition dye comprising one or more imbibition dyes selected from photochromic materials, conventional dyes, dichroic materials and / or photochromic-dichroic materials. The imbibition composition is then heated so that at least a portion of the imbibition dye diffuses or imbibs into the imbibible surface of the substrate. The remaining residual material can be washed off the surface of the imbibitioned substrate. Non-limiting methods of imbibition are described in U.S. Pat. Nos. 6,433,043; 6,713,536; and U.S. Pat. No. 7,147,889, the disclosures of which are incorporated herein by reference in their entirety.

[0043] In some examples, the method of the present invention includes applying an imbibition composition comprising at least one imbibition dye to at least a portion of the outer surface 18 of the imbibition substrate 20 to form a coated substrate with a removable (or temporary) coating. The coated substrate can be treated, for example, by heating radiation, so that at least one imbibition dye is diffused into the substrate. Any remaining residual material can be removed, leaving an imbibition substrate with an imbibition dye layer. For example, the imbibition composition can be applied to the entire external imbibition surface, such as the external surface 18 corresponding to the top surface 12 of the optical substrate 20. The imbibition composition can be conformal with the external imbibition surface 18 or it can form a planar surface on the external surface 18. When the imbibition composition is conformal with the external imbibition surface 18, the morphology of the external surface 18 is maintained on the surface of the imbibition composition, which is opposite to the surface at the interface between the imbibition composition and the external imbibition surface 18. The imbibition composition can be applied to at least a portion of the external imbibition surface 18 of the optical substrate 20 using one or more coating devices and techniques, as described herein.

[0044] In some examples, the imbibition composition according to various examples of the present invention may optionally further include a dynamics enhancing additive (KEA), a photoinitiator and a thermal initiator. In some examples, the imbibition composition optionally contains additives for: flow and wetting, flow control agents, such as poly (2-ethylhexyl) acrylate; auxiliary resins to improve and optimize coating properties; antioxidants; hindered amine light stabilizers; hydroxypropyl cellulose (hydroproxyl cel lulose); and ultraviolet (UV) light absorbers. Examples of useful antioxidants, hindered amine light stabilizers and UV light absorbers include those commercially available from BASF under the trademarks IRGANOX and TINUVIN. When used, these optional additives are typically present in an amount of up to 10% by weight (e.g., 0.05 to 5% by weight).

[0045] In some instances, the imbibition composition according to various examples of the present invention may optionally further include a solvent. Examples of suitable solvents include, but are not limited to, water, acetate, alcohol, ketone, glycol, ether, aliphatic compound, alicyclic compound and aromatic compound. Examples of acetate include, but are not limited to, ethyl acetate, butyl acetate and glycol acetate. Examples of ketones include, but are not limited to, methyl ethyl ketone and methyl-N-amyl ketone. Examples of aromatic compounds include, but are not limited to, toluene, naphthalene and dimethylbenzene. In an example, one or more solvents are added to each of the first reactant and the second reactant. Suitable solvent blends may include, for example, one or more acetates, propanol and derivatives thereof, one or more ketones, one or more alcohols, and / or one or more aromatic compounds. If present, the solvent is usually present in an amount of 5 to 60 % by weight, or 5 to 40 % by weight, or 10 to 25 % by weight, based on the gross weight (including solvent weight) of the imbibition composition.

[0046] In some examples, the solvent may be an aqueous solvent, an organic solvent or a mixture of such solvents, a polymer resin or a mixture of a solvent and a polymer resin. Examples of solvent carriers include water, benzene, toluene, methyl ethyl ketone, acetone, ethanol, tetrahydrofurfuryl alcohol, n-methylpyrrolidone, 2-ethoxyethyl ether, 2-methoxyethyl ether, xylene, cyclohexane, 3-methylcyclohexanone, ethyl acetate, tetrahydrofuran, methanol, methyl propionate, ethylene glycol, acetonitrile, butanol, methyl isobutyl ketone, methyl chloroform, isopropanol and a mixture of such solvents. Examples of polymer resins include hydroxy (C1-C3) alkyl cellulose, poly (vinyl pyrrolidone) (PVP); a mixture of 5 to 50 parts of hydroxy (C1-C3) alkyl cellulose and 95 to 50 parts of PVP, polyvinyl chloride, polyvinyl acetate, polyvinyl butyral, a copolymer of vinyl chloride and vinyl acetate, a copolymer of vinyl chloride and vinylidene chloride, polyvinyl propionate, cellulose acetate butyrate and a mixture of such polymer resins. When the carrier in the imbibing composition is a polymeric resin, the resin essentially acts as a film-forming binder for the other components of the composition.

[0047] In some examples, the imbibition composition may include a static dye, a photochromic material or a combination thereof. The categories and examples of static dyes that may be present in the imbibition composition include, but are not limited to, inorganic electrostatic dyes and organic electrostatic dyes recognized in the art. The electrostatic dye may be present in the imbibition composition and / or the optical substrate 20 in such an amount (or ratio) that the optical article 10 displays the desired optical properties. For the purpose of non-limiting illustration, the amount and type of the static dye may be selected so that the optical article 10 has a color / color corresponding to a permanent gradient of a thermal gradient, as described herein. The amount of the static dye incorporated into the imbibition composition may be 0.1 to 99.9% by weight, based on the weight of the composition. The exact amount of the static dye is not important, as long as sufficient amount is used to produce the desired effect. The specific amount of the electrostatic dye used may depend on various factors, such as, but not limited to, the absorption characteristics, color and color intensity of the static dye, and the method for incorporating the static dye into a specific layer. Although not limited herein, according to various non-limiting examples disclosed herein, the electrostatic dye incorporated into the optical element layer can be configured to contribute to an optical article having a light transmittance of 5% to 100%, such as a transmittance of 10% to 95%, a transmittance of 15% to 90%, or a transmittance of 25% to 75%. With respect to the static dyes alternatively or additionally incorporated into the optical substrate 20 of the optical article 10, the same transmittance range is applicable.

[0048] The categories of photochromic compounds that may be present in the imbibition composition include, but are not limited to, "conventional photochromic compounds". As used herein, the term "conventional photochromic compounds" includes both thermally reversible and non-thermally reversible (or photo-reversible) photochromic compounds. Generally, although not limited herein, when two or more conventional photochromic materials are used in combination with each other, various materials can be selected to complement each other to produce the desired color or hue. For example, according to certain non-limiting examples disclosed herein, a mixture of photochromic compounds can be used to obtain certain activated colors, such as near-neutral gray or near-neutral brown. See, for example, U.S. Patent No. 5,645,767, column 12, line 66 to column 13, line 19, the disclosure of which is specifically incorporated by reference, which describes the parameters defining neutral gray and brown.

[0049] Examples of photochromic materials or compounds that may be present in the imbibition composition include, but are not limited to, indeno-fused naphthopyrans, naphtho[1,2-b]pyrans, naphtho[2,1-b]pyrans, spirofluoren[1,2-b]pyrans, phenanthropyrans, quinopyrans, fluoranthopyrans, spiropyrans, benzopyrans, Oxazine, naphthoxy Oxazine, spiro(dihydroindole)naphtho Oxazine, spiro(dihydroindole)pyridobenzo Oxazine, spiro(dihydroindole)fluoranthene Oxazine, spiro(dihydroindole)quinoline Spiro(indoline)quinoxazine, fulgimide, diarylethene, diarylalkylethylene, diarylalkenylethylene, thermally reversible photochromic compounds, and non-thermally reversible photochromic compounds, and mixtures thereof.

[0050] In some examples, other examples of photochromic compounds that may be present in the imbibing composition may be selected from certain indeno-fused naphthopyran compounds as described in U.S. Patent No. 6,296,785 at column 3, line 66 to column 10, line 51, the disclosure of which is incorporated herein by reference.

[0051] The photochromic compound may be present in the imbibing composition and / or the optical substrate 20 in such an amount (or ratio) that the optical article 10 of the present disclosure exhibits the desired optical properties. For non-limiting illustrative purposes, the amount and type of photochromic compound may be selected so that the optical article 10 is transparent or colorless when the photochromic compound is in a closed form (e.g., in a bleached or unactivated state), and the desired final color may be exhibited when the photochromic compound is in an open form (e.g., when activated by actinic radiation). The exact amount of photochromic compound used is not critical, as long as a sufficient amount is used to produce the desired effect. The specific amount of photochromic compound used may depend on various factors, such as, but not limited to, the absorption characteristics of the photochromic compound, the desired color and color intensity when activated, and the method used to incorporate the photochromic compound into a particular layer. Although not limiting herein, according to various non-limiting examples disclosed herein, the photochromic compound incorporated into the optical element layer can be configured to contribute to an optical article having a light transmittance of 5% to 100% when activated, such as a transmittance of 10% to 95% when activated, a transmittance of 15% to 90% when activated, a transmittance of 25% to 75% when activated. With respect to the photochromic compound alternatively or additionally incorporated into the optical substrate 20 of the optical article 10 of the present disclosure, the same transmittance range is applicable.

[0052] The amount of the photochromic compound incorporated into the imbibition composition can be 0.1 to 99.9 weight %, based on the weight of the composition. In a series of expected embodiments where the imbibition composition is a combination of KEA and a photochromic compound, the amount of the photochromic compound is 25 to 99 weight %, 50 to 98 weight %, or 70 to 97 weight %. The amount of the photochromic compound used in the imbibition composition of the present invention can be between any combination of these values, including the recited ranges, such as 0.15 to 99.85 weight %.

[0053] In a specific example of the present invention, wherein the imbibition composition comprises a material selected from dichroic dyes, photochromic-dichroic dyes and mixtures thereof, the optical substrate 20 comprises an alignment layer capable of diffusing and aligning dichroic dyes and / or photochromic-dichroic dyes. The alignment layer may comprise an ordered liquid crystal material having an irreversibly fixed first general direction (general direction), and the dichroic dyes and / or photochromic-dichroic dyes may be aligned in a second general direction parallel to the first general direction. Non-limiting examples of such alignment layers comprising ordered liquid crystal materials are described in US7,256,921, Column 82, Line 62, to Column 84, Line 11, the cited portion of which is incorporated herein by reference.

[0054] In addition, the alignment layer may include a polymer sheet oriented in a first general direction, and the dichroic dye and / or the photochromic-dichroic dye may be aligned in a second general direction parallel to the first general direction. In a specific embodiment of the present invention, the alignment layer may be linearly polarizing and may include an oriented polymer sheet of polyvinyl alcohol, vinyl butyral, polyethylene terephthalate, polyalkyl (meth)acrylate, polyamide, poly(amide-ether) block copolymer, poly(ester-ether) block copolymer, poly(ether-urethane) block copolymer, poly(ester-urethane) block copolymer and / or poly(ether-urea) block copolymer. As used herein, the term "oriented polymer sheet" refers to a polymer sheet having at least a first general (alignment) direction (e.g., a first general direction imparted to the sheet by stretching).

[0055] The alignment layer can be linearly polarized and can include an optical quality polymer sheet or film containing a dispersed phase of polymer particles disposed in a continuous birefringent matrix, which can be oriented in one or more directions. The size and shape of the dispersed phase particles, the volume fraction of the dispersed phase, the film thickness and the amount of orientation are selected to obtain the desired degree of diffuse reflection and total transmittance of radiation of the desired wavelength in the film. Such sheets / films and their preparation are described in US5,867,316, column 6, line 47 to column 20, line 51, the cited portion of which is incorporated herein by reference. When linearly polarized, the alignment layer may also include a birefringent multilayer optical film described in US5,882,774, column 2, line 63 to column 18, line 31, the cited portion of which is incorporated herein by reference. In addition, the alignment layer may also include a dual component polarizer (i.e., a dichroic and reflective polarizing component), such as those described in US6,096,375, column 3, line 7 to column 19, line 46, the cited portion of which is incorporated herein by reference.

[0056] When present in the imbibition composition, the dichroic material and / or the photochromic-dichroic material is aligned in a second general direction, i.e., along the major axis of the dichroic compound and / or the photochromic-dichroic compound, the second general direction being at least parallel to the first general direction of the alignment layer. As used herein with respect to the ordering or alignment of a material or structure, the term "general direction" refers to the predominant arrangement or orientation of a material, compound or structure. Furthermore, it will be understood by those skilled in the art that a material, compound or structure may have a general direction even if there is some variation in the alignment of the material, compound or structure, provided that the material, compound or structure has at least one predominant arrangement.

[0057] The imbibing composition used in the method of the present invention may further comprise additional conventional ingredients that impart desired physical properties to the composition or resulting layer; additional conventional ingredients required for the method of applying the imbibing composition to a substrate; and / or additional conventional ingredients that enhance the layer made therefrom. These additional ingredients include rheology control agents, such as silica, and leveling agents, such as surfactants.

[0058] The imbibition composition, i.e., KEA, the photochromic compound and optional ingredients, such as adjuvants and other conventional ingredients, can be prepared by any conventional technique. For example, the components can be mixed and used neat, or can be dissolved in a suitable solvent before combining, or each component can be dissolved or incorporated into a suitable carrier sequentially, if necessary, under heating.

[0059] Optical elements prepared by and in accordance with the methods of the present invention may optionally include one or more layers applied over the imbibed dye layer of the imbibed substrate after the remaining residual material has been removed. Such additional examples include, but are not limited to: primer coatings and films; protective coatings and films, including transition coatings and films and abrasion-resistant coatings and films; antireflective coatings and films; polarizing coatings and films; and combinations thereof. As used herein, the term "protective coating or film" refers to a coating film that can protect against friction or wear, provide a property transition from one coating or film to another, protect against the effects of polymerization chemicals, and / or protect against degradation due to environmental conditions such as moisture, heat, ultraviolet light, oxygen, and the like.

[0060] As used herein, the term "transitional coating and film" refers to a coating or film that helps create a property gradient between two coatings or films or a coating and a film. For example, although not limited herein, a transitional coating can help create a hardness gradient between a relatively hard coating and a relatively soft coating. Non-limiting examples of transitional coatings include radiation-cured acrylate-based films as described in U.S. Pat. No. 7,452,611 B2, which is hereby specifically incorporated herein by reference.

[0061] As used herein, the term "wear resistant coatings and films" refers to protective polymeric materials that exhibit wear resistance greater than that of standard reference materials, such as those provided by PPG Industries, Inc. The polymers made from the monomers are tested using a method equivalent to ASTM F-735 Standard Test Method for Abrasion Resistance of Transparent Plastics and Coatings Using the Oscillating Sand Method. Non-limiting examples of wear-resistant coatings include, for example, wear-resistant coatings containing organosilanes, organosiloxanes, wear-resistant coatings based on inorganic materials such as silica, titania and / or zirconium oxide, and organic wear-resistant coatings of the UV-curable type, oxygen barrier coatings, UV shielding coatings and combinations thereof. Non-limiting examples of commercially available hard coating products include CRYSTALCOAT TM 124 and HI- coatings, available from SDC Coatings, Inc. and PPG Industries, Inc., respectively.

[0062] In some examples, the wear-resistant coating or film (or hard coating) can be selected from hard coating materials recognized in the art, such as organosilane wear coatings. Organosilane wear coatings, commonly referred to as hard coatings or silicone-based hard coatings, are well known in the art and are commercially available from various manufacturers, such as SDC Coatings, Inc. and PPG Industries, Inc. Reference is made to U.S. Patent No. 4,756,973, Col. 5, Lines 1 to 45; and U.S. Patent No. 5,462,806, Col. 1, Lines 58 to Col. 2, Line 8, and Col. 3, Lines 52 to Col. 5, Line 50, the disclosures of which describe organosilane hard coatings, and the disclosures are incorporated herein by reference. Reference is also made to the disclosures of organosilane hard coatings of U.S. Patent Nos. 4,731,264, 5,134,191, 5,231,156 and International Patent Publication WO 94 / 20581, which are also incorporated herein by reference. The hard coating may be applied by art-recognized coating methods such as, but not limited to, roller coating, spray coating, curtain coating, and spin coating.

[0063] Non-limiting examples of anti-reflective coatings and films include single layers, multiple layers or films of metal oxides, metal fluorides or other such materials, which can be deposited on the articles disclosed herein (or applied to the films of the articles), for example by vacuum deposition, sputtering, etc. Non-limiting examples of conventional photochromic coatings and films include, but are not limited to, coatings and films comprising conventional photochromic materials.

[0064] The imbibed dye layer of the imbibed substrate and other optional films and / or layers (such as but not limited to one or more additional coatings) formed on or over the imbibed substrate each have at least sufficient transparency to allow observation of an electromagnetic energy source through the optical article 10 and reflection of electromagnetic energy incident on the surface of the optical article 10. In some examples, the imbibed substrate and one or more additional layers each independently have a percent transmittance greater than 0% and less than or equal to 100%, such as 50% to 100%. In other examples, the imbibed substrate and one or more additional coatings have at least sufficient reflectivity to allow reflection of at least a portion of the electromagnetic energy incident on the outer surface of the optical article 10.

[0065] Typically, the thickness of the imbibition dye layer and / or one or more other coatings in the imbibition substrate can be any thickness required to reach the desired thickness of the optical article. For example, the thickness of the imbibition dye layer and / or one or more other coatings in the imbibition substrate can be 2 microns to 60 microns, 10 microns to 40 microns, or 20 microns to 30 microns. The imbibition dye layer and / or one or more other coatings can have the same or different thicknesses.

[0066] The imbibition compositions and optional ingredients can be prepared by any conventional technique. For example, the individual components can be mixed and used neat; or can be dissolved in an appropriate solvent before being combined; or each component can be dissolved or incorporated into a suitable carrier in sequence, if necessary, under heating. Alternatively, multiple (individual) imbibition compositions and imbibition steps can be used to prepare the photochromic articles of the present invention. In a contemplated embodiment, the first imbibition composition is used for the photochromic compound and the stabilizer, the second imbibition composition includes KEA, and the third imbibition composition includes both the photochromic compound (one or more) and KEA (one or more).

[0067] Gradient Pattern

[0068] As described herein, the optical article 10 is configured to exhibit a gradient pattern on at least one surface thereof. In some examples, an imbibing composition having at least one imbibing dye is applied to an optical substrate to form a coated substrate. The coated substrate is then irradiated so that an imbibing dye concentration gradient is formed. The imbibing dye concentration gradient can form at least one light-affected zone that defines a gradient pattern 50 (shown in FIG. Figure 2 As used herein, the term "light-affected zone" refers to a portion of optical article 10 that has the ability to exhibit one or more optical properties when light contacts or passes through optical article 10. Non-limiting examples of light-affecting properties include photochromic and / or photochromic-dichroic reversible changes, color / hue, polarization, or combinations thereof.

[0069] An imbibing composition having at least one imbibing dye can be applied to the imbibing surface of the optical substrate 20 to form at least one light-affected zone having a gradient photochromic and / or photochromic-dichroic reversible change after the imbibing dye(s) of the imbibing composition is imbibed into the optical substrate 20. As used herein, "gradient photochromic and / or photochromic-dichroic reversible change" refers to an increase or decrease in the magnitude or degree of color / hue and / or polarization change throughout at least one light-affected zone when exposed to at least actinic radiation. In order to provide a gradient photochromic and / or photochromic-dichroic reversible change, the imbibing composition can have different amounts of photochromic and / or photochromic-dichroic materials throughout at least one light-affected zone. It will be appreciated that the use of photochromic and photochromic-dichroic materials to provide a gradient polarization and / or color / hue will also provide a gradient photochromic and / or photochromic-dichroic reversible change.

[0070] An imbibing composition having at least one imbibing dye can be applied to the optical substrate 20 to form at least one light-affected zone having a gradient color / hue after the imbibing dye(s) of the imbibing composition is imbibed into the imbibible surface of the optical substrate 20. As used herein, "gradient color / hue" refers to an increase or decrease in the magnitude or degree of color / hue throughout at least one light-affected zone. To provide a gradient color / hue, the imbibing composition can have different amounts of dye throughout at least one light-affected zone.

[0071] In some examples, the imbibition composition is applied to the imbibitionable surface of the optical substrate 20 to form at least one light-affected zone with a gradient polarization after the imbibition dye(s) of the imbibition composition is imbibed into the optical substrate 20. As used herein, "gradient polarization" refers to an increase or decrease in the amplitude or degree of polarization throughout at least one light-affected zone. In order to provide a gradient polarization, the anisotropic material in the alignment layer can have different amounts of aligned dichroic materials and / or different amounts of aligned photochromic-dichroic materials throughout at least one light-affected zone. The amount of aligned dichroic and / or photochromic-dichroic materials can be changed by the current method, for example by incorporating different amounts of dichroic and / or photochromic-dichroic materials throughout at least one light-affected zone.

[0072] The optical article 10 may include two or more light-affecting zones having different light-affecting properties. Thus, the optical article 10 of the present invention may include two or more light-affecting zones having different photochromic and / or photochromic-dichroic reversible changes, different colors / hues, different polarization properties, or any combination thereof.

[0073] like Figure 2As shown, the gradient hue and / or gradient polarization of the optical article 10 can extend across the entire surface of the optical article 10. For example, Figure 2 In some examples, the hue and / or polarization gradient extends from the top of the optical article 10 (where the hue is lightest and / or where there is least polarization, or where there is no hue and / or polarization) to the bottom of the optical article 10 (where the hue is darkest and / or where there is most polarization). In some examples, the top of the optical article 10 may have a transmittance of 90% to 60% when activated, while the bottom of the optical article 10 may have a transmittance of 10% to 60% when activated. However, in other examples, the hue gradient and / or polarization gradient may extend over only a portion of the surface of the optical article 10.

[0074] Optical article 10 can be formed with any combination of the aforementioned non-limiting light-affecting zones and properties. In addition, the optical article can include any desired number of light-affecting zones, including but not limited to two or more, three or more, or four or more light-affecting zones. The number and type of light-affecting zones can be selected based on the desired use of optical article 10.

[0075] Coating device and method

[0076] Prior to applying the imbibing composition to the optical substrate 20, the surface of the optical substrate 20 is preferably cleaned. Cleaning can be accomplished by washing the surface with an aqueous medium (e.g., soapy water) to remove dust and dirt; washing the surface with an organic solvent such as methyl ethyl ketone to remove any organic film present on the surface; and / or eliminating static charges present on the surface of the optical substrate 20.

[0077] The optical substrate 20 may be subjected to an additional surface pretreatment step. The pretreatment step may include, but is not limited to, plasma, flame, chemical (e.g., caustic), or any treatment for increasing the surface energy of the substrate so that the first coating wets the optical substrate and promotes adhesion to the optical substrate. For example, as described in U.S. Pat. No. 8,608,988, the optical substrate may be treated with corona discharge from a Tantec EST-Electrical Service Treatment unit operated at 500 watts and 54 kVA for 30 to 90 seconds to activate the substrate surface.

[0078] refer to Figure 3, the optical article 10 can be manufactured using a coating device 50. The coating device 50 is configured to apply a coating material, such as an imbibition composition comprising at least one imbibition dye, on an imbibition surface (e.g., one or more imbibition surfaces of an optical substrate 20). The coating device 50 is configured to deposit one or more droplets 40 of a coating material continuously or on demand on at least one imbibition surface of an optical substrate 20. The controller can control the volume of the coating material applied to the optical substrate 20. In various examples, the coating device 50 can be an inkjet coating device, an ultrasonic nozzle coating device, a spray coating device, a spin coating device, a dip coating device or a curtain coating device. Specific non-limiting examples of such coating devices are described in PCT / EP2016 / 066896 and PCT / EP2016 / 055201, the disclosures of which are incorporated herein by reference. It should be understood that the coating device 50 can be configured as a combination of various devices, which are configured to apply a coating to at least one surface of an optical substrate 20.

[0079] When applied to at least one surface of the optical substrate 20, one or more droplets 40 form a coating that, when irradiated with heat, allows the imbibition dye (one or more) to diffuse into the imbibition surface of the optical substrate 20. In various examples, the thickness of the imbibition composition coating can be a minimum of 1 μm to a maximum of 100 μm, preferably 10 μm to 50 μm. In an example where the coating is applied to a curved optical substrate 20, the application of the coating composition can be controlled in various regions of the optical substrate 20 to cause the coating composition to move on the curved surface of the optical substrate 20. For example, on a convex substrate 20, the amount of coating material applied on the radial inner portion of the optical substrate 20 can be higher than the amount of coating material applied on the radial outer portion of the optical substrate 20 to form a coating having a uniform thickness. In various examples, the coating can have a uniform or non-uniform thickness on the optical substrate 20.

[0080] Continue to refer Figure 3, the coating device 50 includes a workpiece support 60. In some examples, the workpiece support 60 can be configured to firmly hold the optical article 10 during the coating process. In other examples, the workpiece support 60 can be a belt or track for supporting the bottom surface of the optical article 10. A plurality of optical articles 10 can be removably fixed to the workpiece support 60. Each optical article 10 is held in the workpiece support 60 so that the surface of the optical article 10 to be coated ("coating surface 45") faces the coating device 50. In some examples, the plane of the coating surface 45 can be substantially perpendicular to the downward direction of the coating applied by the coating device 50. In other examples, the plane of the coating surface 45 can be at an angle relative to the direction of the coating applied by the coating device 50. In some examples, the workpiece support 60 can be configured to hold a frame, such as an eyeglass frame, with the optical article 10 mounted therein. A plurality of frames can be removably fixed in the workpiece support 60.

[0081] The workpiece support 60 may be fixed or movable relative to the coating device 50. In one example, the workpiece support 60 remains stationary in a fixed position together with the optical substrate 20 fixed thereto, and the coating device 50 translates or rotates relative to the workpiece support 60 on one, two, or three axes to position the coating device 50 at a desired position relative to the workpiece support 60 and the optical substrate (one or more) 20. In another example, the workpiece support 60 can translate or rotate relative to the fixed coating device 50 on one, two, or three axes to position the workpiece support 60 and the optical substrate (one or more) at a desired position relative to the coating device 50. In another example, both the workpiece support 60 and the coating device 50 can be movable, such as by translation or rotation. In this way, the workpiece support 60 and the coating device 50 can have up to six degrees of freedom (translation of three axes and rotation about three axes) to move so as to position the coating device 50 at a predetermined position relative to the optical substrate (one or more) 20. The workpiece support 60 and coating device 50 may be moved manually, or their movement may be controlled by one or more motors in electronic communication with the controller. The movement of the workpiece support 60 and coating device 50 may be predetermined, such as by computer executable instructions executed by the controller.

[0082] Before using the coating apparatus to coat the surface of the optical substrate 20, the uncoated substrate 20 can be loaded into the workpiece holder 60. The coated substrate 20 can then be optionally removed from the workpiece holder 60 for further processing, as described herein. In some examples, multiple workpiece holders 60 (not shown) can be arranged in a continuously moving line so that multiple optical substrates 20 can be coated in a continuous process.

[0083] Continue to refer Figure 3, the coating device 50 may have a controller 70 for controlling the operation of the coating device 50. The controller 70 may be configured to control the coating operation, such as delivering one or more coating compositions to the coating device 50, the flow rate of one or more coating compositions, and various parameters related to applying one or more coating compositions using the coating device 50. The controller 70 may also control the movement operation of the workpiece support 60 and / or the coating device 50.

[0084] Heat source and irradiation method

[0085] As discussed herein, the present invention relates to methods and apparatus for preparing an optical article 10 that, when exposed to actinic radiation, has a pattern, such as a linear gradient pattern, on the surface of the optical article 10. For purposes of the present invention, the gradient pattern is achieved by controlling the diffusion of an imbibing dye in an imbibing composition and by controlling the exposure of a substrate coated with the imbibing composition to a heat source such that a gradient of color and / or color density or polarization across an area of ​​the optical article 10 is formed when the optical article 10 is exposed to actinic radiation.

[0086] After the imbibing composition is applied to the surface(s) of the optical substrate 20, the imbibing composition is diffused into the optical substrate 20 by heating at least a portion of the optical substrate 20 at a temperature below the boiling temperature of the imbibing dye(s). The temperature to which the coated optical substrate 20 is heated will vary and depend on the boiling point and vapor pressure of the specific imbibing dye(s) used, as well as the softening temperature of the optical substrate 20. Such a temperature should preferably be close to but below the boiling point of the imbibing dye(s) and below the softening temperature of the optical substrate 20. In addition, such a temperature, i.e., the photochromic transfer or incorporation temperature, should be such as to avoid decomposition (thermal decomposition) of the imbibing dye(s). Thus, the selected transfer temperature is sufficient to sufficiently increase the vapor pressure of the imbibing dye(s) to allow its transfer into the optical substrate 20 without significantly decomposing the compound and softening the optical substrate 20.

[0087] refer to Figure 4 , heating can be accomplished with a heat source 80. The heat source 80 is configured to irradiate at least a portion of an optical substrate 20 that has been coated with an imbibing composition having an imbibing dye with electromagnetic energy. The heat source 80 is configured to irradiate at least a portion of at least one surface of the coated optical substrate with electromagnetic energy so that the imbibing dye(s) of the imbibing composition diffuse into the optical substrate 20. A controller can control the output of the heat source 80 to control the amount of electromagnetic energy to which the optical substrate 20 is exposed. In various examples, the heat source 80 can be an infrared heat source, a convection heat source, or a microwave heat source. It should be understood that the heat source 80 can be configured as a combination of these heat sources. The heat source 80 can have one or more heating elements having a linear or curved profile.

[0088] The coated optical substrate 20 is maintained at the above-described temperature for a sufficient period of time to allow a substantial portion of the imbibing dye(s) to diffuse into and penetrate beneath the surface of the optical substrate 20. The length of time that the optical substrate 20 is irradiated with electromagnetic energy from the heat source 80 is ideally selected to result in diffusion of the imbibing dye(s) in the imbibing composition applied to at least one imbibible surface of the optical substrate 20. The heating may also be accomplished in a vacuum or using an inert, such as nitrogen, atmosphere.

[0089] Continue to refer Figure 4 , the heat source 80 can be offset relative to the optical substrate 20. For example, the central axis A of the heat source 80 can be offset from the central axis of the optical substrate 20 by a predetermined offset amount B. In various examples, the predetermined offset amount B can be expressed as a percentage of the total longitudinal length L of the optical substrate 20 that the central axis A of the heat source 80 is offset from the central axis C of the optical substrate 20. For example, the central axis A of the heat source 80 can be laterally offset from the central axis C of the optical substrate 20 by 10% to 1000%, preferably 30% to 90%, of the total longitudinal length L of the optical substrate 20. In other examples, the distance D between the optical substrate 20 and the heat source 80 can be from a minimum of 100 mm to a maximum of 10,000 mm, preferably from 500 mm to 5,000 mm.

[0090] refer to Figure 5 , the heat source 80 and the optical substrate 20 can be at an angle relative to each other. For example, the longitudinal axis D of the optical substrate 20 can be offset relative to the X-axis at a predetermined angle α. In various examples, the absolute value of the predetermined angle α can be 10° to 80°, preferably 30° to 60°. In some examples, the heat source 80 and the optical substrate 20 can be offset relative to each other, for example Figure 4 and are at an angle relative to each other, such as Figure 5 as shown in .

[0091] The offset of the heat source 80 relative to the optical substrate 20 forms a thermal gradient across the optical substrate 20 (e.g., at least one permeable surface of the optical substrate 20). The thermal gradient on the at least one permeable surface of the optical substrate 20 causes the imbibition dye(s) in the imbibition composition to diffuse into the permeable surface of the optical substrate 20 in a manner corresponding to the thermal gradient. In this manner, the concentration gradient of the imbibition dye(s) diffused into the at least one permeable surface of the optical substrate 20 corresponds to the thermal gradient across the at least one permeable surface. As described herein, the concentration gradient of the imbibition dye(s) forms a gradient pattern when the optical article 10 is exposed to actinic radiation. The gradient pattern can be fixed (e.g., when conventional dyes or dichroic dyes are used), variable in response to actinic radiation (e.g., when photochromic or photochromic-dichroic dyes are used), or a combination of both (when more than one type of imbibition dye is used).

[0092] In various examples, the thermal gradient across at least one permeable surface of the optical substrate 20 can be controlled by increasing or decreasing the output of the heat source 80. Additionally or alternatively, the thermal gradient across at least one permeable surface of the optical substrate 20 can be controlled by increasing or decreasing the distance D between the optical substrate 20 and the heat source 80. Additionally or alternatively, the thermal gradient across at least one permeable surface of the optical substrate 20 can be controlled by increasing or decreasing a predetermined offset B between the optical substrate 20 and the heat source 80. Additionally or alternatively, the thermal gradient across at least one permeable surface of the optical substrate 20 can be controlled by increasing or decreasing the time that the optical substrate 20 is exposed to the electromagnetic energy from the heat source 80.

[0093] The heat source 80 and / or the workpiece support 60 supporting the optical substrate 20 may be arranged in a lateral direction ( Figure 4 The heat source 80 may be movable in the vertical direction (the X-axis in the figure) to position the heat source 80 at a desired lateral offset relative to the optical substrate 20. In some examples, the heat source 80 and / or the workpiece support 60 supporting the optical substrate 20 may also or alternatively be movable in the vertical direction (the X-axis in the figure). Figure 4 The heat source 80 may be movable along the Y-axis (in the Y axis) to position the heat source 80 at a desired vertical offset relative to the optical substrate 20. In other examples, the heat source 80 and / or the workpiece support 60 supporting the optical substrate 20 may also or alternatively be arranged around ( Figure 4The workpiece support 60 and the heat source 80 may be rotated about the Z-axis (in the Z-axis) to position the heat source 80 at a desired angular position relative to the optical substrate 20. In one example, the workpiece support 60 and the optical substrate 20 supported thereon remain stationary in a fixed position, and the heat source 80 is translated or rotated relative to the workpiece support 60 in one, two, or three axes to position the heat source 80 at a desired position relative to the workpiece support 60 and the optical substrate 20. In another example, the workpiece support 60 may be translated or rotated in one, two, or three axes relative to the fixed heat source 80 to position the workpiece support 60 and the optical substrate 20 at a desired position relative to the heat source 80. In another example, both the workpiece support 60 and the heat source 80 may be movable, such as by translational or rotational motion. In this manner, the workpiece support 60 and the heat source 80 may have up to six degrees of freedom (translation in three axes and rotation about three axes) to move so as to position the heat source 80 at a predetermined position relative to the optical substrate 20.

[0094] In some examples, the workpiece support 60 and / or the heat source 80 can remain stationary relative to each other when the optical substrate 20 is irradiated with electromagnetic energy from the heat source 80. In other examples, the workpiece support 60 and / or the heat source 80 can move relative to each other when the optical article 20 is irradiated with electromagnetic energy from the heat source 80. For example, the speed at which the workpiece support 60 and / or the heat source 80 move relative to each other can be constant or variable during the irradiation process. The speed at which the workpiece support 60 and / or the heat source 80 move relative to each other can depend on the concentration of the imbibed dye, the temperature of the heat source 60, and / or the relative ease with which the imbibed dye diffuses into the optical substrate 20. The workpiece support 60 and the heat source 80 can be moved manually, or their movement can be controlled by one or more motors in electronic communication with the controller. The movement of the workpiece support 60 and the heat source 80 can be predetermined, such as by computer executable instructions executed by the controller.

[0095] Continue to refer Figure 4 , heat source 80 can have a controller 70 for controlling the operation of heat source 80. Controller 70 can be configured to control the output of heat source 80, the position of heat source 80 relative to optical substrate 20, and various parameters related to irradiating at least a portion of at least one surface of optical substrate 20 with electromagnetic energy using heat source 80.

[0096] In some examples, multiple heat sources 80 can be arranged in an array. Multiple heat sources 80 can be arranged parallel or offset from each other in one or more rows and / or columns. The heat sources 80 can be offset from each other by a distance from a minimum of 1 mm to a maximum of 1000 mm, preferably from 100 mm to 500 mm.

[0097] Removal of residual components

[0098] After the imbibing dye(s) are transferred into the optical substrate 20, the residual coating or film is removed from the surface of the optical substrate 20. The residual coating or film may be removed by any suitable technique; preferably a technique that does not damage the optical quality of the surface of the optical substrate 20. Conveniently, the residual coating or film is stripped from the optical substrate 20 by contacting the residual coating or film with a suitable solvent (e.g., soapy water or an organic solvent such as trichloroethylene, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketone-toluene mixtures, or other solvents such as acetone, ethylene dichloride, chloroform, and chlorobenzene). The same solvent used to prepare the imbibing composition can be used to remove the residual coating or film. A suitable method of contacting the residual coating or film with an organic solvent is in a vapor degreasing unit, wherein the coated substrate is exposed to vapors of the selected solvent(s), which condense on the surface of the optical substrate 20 and flow out, thereby washing the photochromic and / or KEA-depleted resin film or coating from the surface. Alternatively, the residual coating or film may be removed by immersing the optical substrate 20 in a solvent bath, spraying a solvent onto a coated substrate, or physically peeling the film or coating from the optical substrate 20. After the residual coating or film has been removed from the surface of the optical substrate 20, the surface may then be washed with water, a solvent, or a suitable aqueous medium (e.g., a soap or detergent solution), and dried.

[0099] Example

[0100] The imbibition solutions of the photochromic dyes were prepared using the ingredients listed in Table 1 below.

[0101] Table 1. Imbibition solutions

[0102]

[0103]

[0104] 1 A mixture of organic photochromic dyes formulated to display a grey color when activated.

[0105] 2 Hindered amine UV stabilizers available from Ciba-Geigy Corporation.

[0106] 3 Molecular weight: 550.

[0107] CR-607 lenses (base 5 curvature) with a diameter of 76 mm obtained from PPG Industries, Inc. were spin coated with the imbibition solutions prepared according to Table 1 above.

[0108] The coated lens is placed in a fume hood with a face velocity of 1.05 m / s. A preheated IR lamp (model 4185-16-1600) available from Control IR Infrared Heaters is used as a heat source and is arranged 10 cm above the highest point of the lens surface and 3 cm away from the center of the lens. The irradiance is set to 30% using a Control IR Unit Model 5420-240-0 from Control IR Infrared Heaters. The lens is heated for 2.5 hours.

[0109] The surface temperature of the portion of the lens closest to the heat source (measured near the edge) was measured using an IR thermometer to be 140° C. The surface location farthest from the heat source was measured to be 60° C. After 2.5 hours of heat exposure, the lens was allowed to cool and residual resin was removed from the lens by hand using a sponge and deionized water.

[0110] The lenses were then surfaced and coated with Omega Optix's anti-reflective coating Green AR.

[0111] The finished lens was activated using a UV light source. The activated lens showed an aesthetically acceptable color gradient, with the darkest areas corresponding to the portions of the lens exposed to the highest temperatures. A faint lighter-colored ring was evident only around the perimeter of the lens in the photochromic area. The ring was approximately 5 mm wide.

[0112] In various examples, the present invention may also be characterized by one or more of the following:

[0113] Clause 1. A method of making an optical article, the method comprising:

[0114] applying an imbibing composition comprising at least one dye to at least a portion of at least one imbibible surface of a substrate to form a coated substrate;

[0115] irradiating at least a portion of the coated substrate with heat from a heat source to form a thermal gradient across the coated substrate to diffuse at least one dye into the imbibible surface to form an at least partially imbibible substrate having a dye concentration gradient corresponding to the thermal gradient; and

[0116] removing residual components of the imbibing composition from the at least partially imbibed substrate,

[0117] The gradient of dye concentration forms a gradient pattern when exposed to actinic radiation.

[0118] Item 2. The method of Item 1, wherein the permeable surface is the surface of a permeable substrate.

[0119] Item 3. The method of Item 1, wherein the permeable surface is a surface of a permeable layer located on an optical article.

[0120] Clause 4. The method of any of clauses 1-3, wherein the thermal gradient is varied by increasing or decreasing the heat output of the heat source.

[0121] Clause 5. The method of any of Clauses 1-4, wherein the thermal gradient is varied by increasing or decreasing the distance between the substrate and the heat source.

[0122] Clause 6. The method of any of Clauses 1-5, wherein the thermal gradient is varied by increasing or decreasing the angle between the substrate and the heat source.

[0123] Clause 7. The method of any of Clauses 1-6, wherein the thermal gradient is varied by increasing or decreasing the time the substrate is exposed to heat from the heat source.

[0124] Clause 8. The method of any of Clauses 1-7, wherein a central portion of the heat source is offset relative to a central portion of the substrate.

[0125] Item 9. The method of any one of Items 1-8, wherein the imbibing composition is applied by a method selected from spin coating, spray coating, inkjet coating, curtain coating or dip coating.

[0126] Clause 10. The method of any of Clauses 1-9, wherein the heat source is selected from an infrared heat source, a convection heat source, and a microwave heat source.

[0127] Clause 11. The method of any of Clauses 1-10, wherein the heat source is curved.

[0128] Item 12. The method of any of Items 1-11, wherein the at least one dye is selected from fixed shading dyes, photochromic dyes, dichroic dyes, and photochromic dichroic dyes.

[0129] Item 13. The method of any of Items 1-12, wherein the substrate is an anisotropic imbibible substrate, and wherein the imbibition composition comprises at least one dichroic dye such that the at least partially imbibible substrate has a polarization gradient pattern.

[0130] Item 14. The method of any of Items 1-12, wherein the substrate is an anisotropic imbibible substrate, and wherein the imbibition composition comprises at least one photochromic dichroic dye such that the at least partially imbibitioned substrate has a photochromic polarization gradient pattern when exposed to actinic radiation.

[0131] Clause 15. The method of any of Clauses 1-14, wherein the imbibing composition further comprises at least one of a UV absorber composition, an antioxidant composition, hydroxypropyl cellulose, a hindered amine light stabilizer, a kinetic enhancing additive, and a solvent.

[0132] Item 16. An optical article having a gradient pattern, the optical article being obtainable by the method of any one of Items 1-15.

[0133] The invention has been described with reference to specific details of specific examples of the invention. Unless such details are included in the appended claims, they should not be construed as limiting the scope of the invention.

Claims

1. A method for manufacturing an optical product (10), the method comprising: applying an imbibing composition comprising at least one dye to at least a portion of at least one imbibible surface of a substrate (20) to form a coated substrate; irradiating at least a portion of the coated substrate with heat from a heat source (80) to form a thermal gradient across the coated substrate to diffuse at least one dye into the imbibible surface to form an at least partially imbibible substrate having a dye concentration gradient corresponding to the thermal gradient; and removing residual components of the imbibing composition from the at least partially imbibed substrate, wherein the dye concentration gradient forms a gradient pattern (18) when exposed to actinic radiation, and wherein a central portion of the heat source (80) is offset relative to a central portion of the substrate (20) to form a thermal gradient across the coated substrate, wherein the substrate (20) remains stationary relative to the heat source (80) while the substrate (20) is irradiated, and The thickness of the imbibition composition coating is from a minimum of 1 μm to a maximum of 100 μm.

2. The method of claim 1, wherein the permeable surface is the surface of a permeable substrate.

3. The method of claim 1, wherein the permeable surface is a surface of a permeable layer located on the optical article (10).

4. The method according to any one of claims 1-3, wherein the thermal gradient is varied by increasing or decreasing the heat output of the heat source (80).

5. The method according to any one of claims 1 to 4, wherein the thermal gradient is varied by increasing or decreasing the time that the substrate (20) is exposed to heat from the heat source.

6. The method according to any one of claims 1 to 5, wherein the imbibing composition is applied by a method selected from spin coating, spray coating, inkjet coating, curtain coating or dip coating.

7. The method according to any one of claims 1 to 6, wherein the heat source (80) is selected from an infrared heat source, a convection heat source and a microwave heat source.

8. The method according to any one of claims 1-7, wherein the heat source (80) is curved.

9. The method according to any one of claims 1 to 8, wherein the at least one dye is selected from fixed shading dyes, photochromic dyes, dichroic dyes and photochromic dichroic dyes.

10. The method according to any one of claims 1 to 9, wherein the substrate (20) is an anisotropic imbibible substrate, and wherein the imbibition composition comprises at least one dichroic dye, such that the at least partially imbibitioned substrate has a polarization gradient pattern.

11. The method of any one of claims 1-10, wherein the substrate is an anisotropic imbibible substrate, and wherein the imbibition composition comprises at least one photochromic dichroic dye such that the at least partially imbibitioned substrate has a photochromic polarization gradient pattern when exposed to actinic radiation.

12. The method according to any one of claims 1-10, wherein the imbibition composition further comprises at least one of a UV absorber composition, an antioxidant composition, hydroxypropyl cellulose, a hindered amine light stabilizer, a kinetic enhancement additive, and a solvent.

13. An optical article having a gradient pattern, obtainable by the method according to any one of claims 1 to 12.

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