Method for preparing functional laminate

Abstract

To provide a method for preparing a functional laminate.SOLUTION: A method for preparing a laminate or a laminated lens includes: obtaining a first plastic base material having a front face and a back face; treating the front face of the first plastic base material or the back face of the first plastic base material; and laminating a second plastic base material on the treated front face of the first plastic base material or the treated back face of the first plastic base material. The treatment can include applying a polyurethane resin to the surface of the first plastic base material. The method can further include treating the surface of the second plastic base material. The method further includes applying an activator on the treated surface of the first plastic base material and the second plastic base material, and laminating the plastic base materials by arranging the treated surfaces of the first plastic base material and the second plastic base material side by side.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to functional laminates, particularly functional thermoplastic polyurethane laminates, for application in optical devices and optical lenses. [Background technology]

[0002] Functional and / or photochromic films can be used to add protection or various optical properties to optical devices and lenses. Functional films can provide mechanical and general functional properties, such as polarization, color, UV protection, blue light blocking, photochromic properties, and / or electrochromic properties. Photochromic films can provide photochromic properties. However, due to their soft texture, both sides of functional and / or photochromic films are typically laminated with optical thermoplastic films to provide the necessary rigidity for further processing and application. For example, when applied to the curved surface of an optical lens, the resulting polymer laminate must have sufficient integrity to ensure adhesion between the thermoplastic films of the laminate and avoid peeling or delamination during cutting and forming.

[0003] Such bonding between the functional and / or photochromic film and the optical thermoplastic film is typically achieved using an adhesive. Often, the adhesive can be cured using either a thermal or ultraviolet (UV) curing process. For example, commercially available adhesives, such as UV-curable acrylic-based adhesives and polyurethane-based adhesives, are used to bond the functional and / or photochromic film to the thermoplastic film in the laminate. In some cases, film treatments such as caustic, plasma, or corona treatments have been implemented, although these require complex processes and expensive equipment.

[0004] However, these approaches, in addition to having a high environmental impact, also introduce limitations and drawbacks that affect their applicability. For example, due to the moisture and heat sensitivity of some functional and / or photochromic films, thermal curing at high temperatures (e.g., 80°C to 100°C) can cause bubbles to form, which can present aesthetic challenges. In another example, due to the sensitivity of some functional and / or photochromic films to UV light, UV curing can cause the film to yellow, which can present unpleasant aesthetic challenges. Summary of the Invention [Problem to be solved by the invention]

[0005] Thus, although adhesives and methods exist for preparing functional film-containing laminates, there is a continuing need for improvements in this area, at least in view of the above-mentioned shortcomings of current approaches.

[0006] The above "Background" discussion is intended to generally present the context of the present disclosure. Aspects of the inventors' efforts to the extent described in this Background section and the discussion that may not otherwise qualify as prior art at the time of filing are not admitted, explicitly or implicitly, as prior art to the present disclosure. [Means for solving the problem]

[0007] The present disclosure relates to methods for preparing laminated optical devices.

[0008] In one embodiment, the present disclosure further relates to a method for preparing a laminate or laminated lens comprising obtaining a first plastic substrate having a front surface and a back surface, treating the front surface of the first plastic substrate or the back surface of the first plastic substrate, and laminating a second plastic substrate onto the treated front surface of the first plastic substrate or the treated back surface of the first plastic substrate, wherein the treating comprises applying a polyurethane resin to the front surface of the first plastic substrate or the back surface of the first plastic substrate, wherein the applied polyurethane resin is a polyester polyurethane resin, a polyether polyurethane resin, or a polycaprolactone resin, and the treating comprises applying isopropyl alcohol or methanol in combination with water to the applied polyurethane resin.

[0009] In one embodiment, the present disclosure further relates to a method for preparing a laminate or laminated lens, comprising obtaining a first plastic substrate having a front and a back surface, treating the front surface of the first plastic substrate or the back surface of the first plastic substrate, and laminating a second plastic substrate onto the treated front surface of the first plastic substrate or the treated back surface of the first plastic substrate. The method further comprises treating the front surface of the second plastic substrate or the back surface of the second plastic substrate, and laminating comprises juxtaposing the treated front surface of the first plastic substrate or the treated back surface of the first plastic substrate and the treated front surface of the second plastic substrate or the treated back surface of the second plastic substrate, and treating comprises applying a polyurethane resin to the front surface of the first plastic substrate or the back surface of the first plastic substrate, applying a polyurethane resin to the front surface of the second plastic substrate or the back surface of the second plastic substrate, and applying isopropyl alcohol or methanol in combination with water to the applied polyurethane resin of the first plastic substrate and the applied polyurethane resin of the second plastic substrate.

[0010] The above paragraphs have been provided by way of a general introduction and are not intended to limit the scope of the claims that follow. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings, in which:

[0011] A more complete understanding of the present disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which: [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram of a molding device according to one embodiment of the present disclosure. [Figure 2A] FIG. 1 is a flow diagram of a method for preparing a laminate or laminated lens according to an exemplary embodiment of the present disclosure. [Figure 2B] FIG. 1 is a flow diagram of sub-processes of a method for preparing a laminate or laminated lens, according to an exemplary embodiment of the present disclosure. [Figure 3] 1 is an illustration of a flow diagram of a method for preparing a laminate or laminated lens, according to an exemplary embodiment of the present disclosure. [Figure 4A] FIG. 1 is a flow diagram of a method for preparing a laminate or laminated lens according to an exemplary embodiment of the present disclosure. [Figure 4B] FIG. 1 is a flow diagram of sub-processes of a method for preparing a laminate or laminated lens, according to an exemplary embodiment of the present disclosure. [Figure 5] 1 is an illustration of a flow diagram of a method for preparing a laminate or laminated lens, according to an exemplary embodiment of the present disclosure. [Figure 6] 1 is a table of adhesive strengths for methods of preparing laminates or laminated lenses according to exemplary embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] The terms "a" or "an," as used herein, are defined as one or more than one. The term "plurality," as used herein, is defined as two or more than two. The term "another," as used herein, is defined as at least two or more. The terms "including" and / or "having," as used herein, are defined as comprising (i.e., open language). References throughout this document to "one embodiment," "particular embodiment," "embodiment," "implementation," "example," or similar terms mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of such phrases in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments, without limitation.

[0014] The term "about" or "approximately" is defined as close as understood by one of ordinary skill in the art. In one non-limiting embodiment, the term is defined to be within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%.

[0015] The terms "laminate" and "laminated lens" or variations of these terms when used in the claims and / or specification refer to similar structures.

[0016] The term "substantially" and variations thereof are defined to include ranges of within 10%, within 5%, within 1%, or within 0.5%.

[0017] The terms "inhibit," "reduce," "prevent," or "avoid," and variations thereof, when used in the claims and / or specification, include any measurable reduction or complete inhibition to achieve a desired result.

[0018] The term "effective," as used in the specification and / or claims, means adequate to accomplish a desired, expected, or intended result.

[0019] The processes of the present disclosure can "comprise," "consist essentially of," or "consist of" certain ingredients, components, compositions, etc., disclosed throughout this specification.

[0020] The terms "first plastic substrate," "first plastic film," and "Film A" may be used interchangeably in the specification and / or claims, but are intended to refer to the same or similar materials. The terms "second plastic substrate," "second plastic film," and "Film B" may be used interchangeably in the specification and / or claims, but are intended to refer to the same or similar materials.

[0021] The terms "TPU photochromic film" and "TPU film" may be used interchangeably in the specification and / or claims, but are intended to refer to the same or similar materials.

[0022] To add additional optical properties to optical lenses, functional and / or photochromic films can be incorporated. However, due to the typically soft texture of photochromic and / or functional films, thermoplastic films such as polycarbonate (PC) or cellulose triacetate (TAC) are often laminated to both surfaces of the photochromic and / or functional films to form a laminate with sufficient material strength to withstand the forming process when the laminate is incorporated onto the surface of an optical lens. For example, thermoplastic polyurethane (TPU) photochromic films have an A hardness of 45 to 85, and therefore need to be laminated with harder PC or TAC films to form a laminate suitable for further lens integration.

[0023] To this end, FIG. 1 is a schematic diagram of a molding device for incorporating a laminate on a surface of an optical lens. The molding device can include a first molding surface 145a, a second molding surface 145b, a concave molding insert 141, and a convex molding insert 142. Each of the first molding surface 145a and the second molding surface 145b can include a hollow portion into which the concave molding insert 141 and the convex molding insert 142 can be removably disposed. As shown in FIG. 1, the first molding surface 145a, including the concave molding insert 141, can be configured to mate with the second molding surface 145b, including the convex molding insert 142. When coupled, the concave molding insert 141 and the convex molding insert 142 can form a cavity connected to the hollow line formed by the joining of the first and second molding surfaces 145a, 145b. The line can be configured to receive the polymer, for example, via a screw feeder or similar device. The cavity can be configured to receive a thermoformed laminate wafer 150. The curvature of the concave mold insert 141 and the curvature of the convex mold insert 142 can determine the optic power of the resulting lens. In one embodiment, the optical lens can include PC, polymethyl methacrylate (PMMA), polystyrene, polystyrene maleic anhydride, polyamide, thermoplastic urethane, thermoset polyurethane, polyester, copolyester, polysulfone, cyclic olefin copolymer (OCO), polyphenyloxide, allyl diglycol carbonate, polythiourethane, episulfur polymer, epoxy, poly(meth)acrylate, polythiomethacrylate, or combinations thereof. For semi-finished lenses, the curvature along the concave surface of the lens is fixed, and the convex surface of the lens can be altered after molding, for example, by grinding or polishing. It should be noted that multiple lines for receiving polymer can be connected together so that the injection of polymer from a source can fill multiple molding devices with a single injection, allowing for the parallel production of multiple lenses.

[0024] Prior to placement in a molding device and lens integration, the flat laminate wafer formed by the processes described and illustrated herein can be thermoformed, for example, by a thermoformer, into the spherical dome shape of the thermoformed laminate wafer 150. During thermoforming, the flat laminate wafer can be placed on a heated thermoform insert, and a vacuum force can be applied to secure the flat laminate wafer to the thermoform insert. By adjusting the temperature of the applied heat and the applied vacuum force, the flat laminate wafer can be formed into the curvilinear shape of the thermoform insert to produce the thermoformed laminate wafer 150.

[0025] In one embodiment, a flat laminate wafer, also referred to herein as a “functional laminate,” “laminate,” and “TPU laminate,” among other obvious derivatives, can include a first layer 111, a central layer 120, and a second layer 112. In embodiments of the present disclosure, the first layer 111, also referred to herein as a “first plastic film,” “film A,” and “first plastic substrate,” can be a thermoplastic film; the central layer 120 can be a functional film and / or a photochromic film; and the second layer 112, also referred to herein as a “second plastic film,” “film B,” and “second plastic substrate,” can be a thermoplastic film. Flat laminate wafers are described in more detail in the remainder of this disclosure. However, as shown in FIG. 1 , a flat laminate wafer can be thermoformed to produce a curved structure having a concave first layer 111 and a convex second layer 112. It can be appreciated that the flat laminate wafer can be thermoformed using known devices and methods, for example, a LEMA fabricator, which gradually increases the curvature of the flat laminate wafer under the application of heat.

[0026] Several methods are available for producing flat laminate wafers that can withstand the physical requirements of thermoforming processes and molding devices. For example, if the central layer 120 is a TPU photochromic film, several commercially available adhesives, such as UV-curable acrylic-based adhesives or polyurethane-based adhesives, may be used. However, these adhesives require either UV curing or heat curing, or both, which require curing energy and curing equipment, thus complicating the overall lamination process. Furthermore, some water-based hot-melt adhesives used for TPU photochromic lamination with PC or TAC require heat during lamination and may even require TPU photochromic film treatment prior to lamination.

[0027] Furthermore, certain pressure-sensitive adhesives, such as tapes that do not require heat, water, or solvents, result in laminates with low material strength (<15 N / inch) as determined by adhesion measurements, and therefore risk delamination during lens manufacturing and assembly.

[0028] Any alternatives to the above primarily rely on mass manufacturing capabilities, such as roll-to-roll film lamination processes, which are not applicable in smaller scale settings such as laboratories or clinics. Furthermore, to ensure sufficient adhesion of the laminate, which includes, for example, a first plastic film, a functional film, and a second plastic film, the roll-to-roll film lamination process needs to be completed almost immediately, which is not feasible.

[0029] In view of the above, the present disclosure describes functional laminates that can be used in injection molding or casting processes, thereby allowing the integration of the functional laminate with an optical lens to provide the functional lens with improved photochromic performance and properties.

[0030] In one embodiment, the functional laminate comprises a TPU photochromic film. The functional laminate can be formed without heat, UV radiation, or film treatments such as corona or plasma treatments.

[0031] According to one embodiment, functional laminates, such as photochromic laminates, produced by the methods described herein exhibit rapid photochromic fading rates (i.e., t in 30 seconds). 0.5 Such photochromic laminates demonstrated good adhesion after injection molding, formulation finishing, and hard coating.

[0032] In one embodiment, the present disclosure describes a method for laminating a functional TPU film onto a first plastic film, a functional TPU film onto a second plastic film, and a method for laminating the first and second plastic films at room temperature under pressure. The method may include adding alcohol or alcohol and water to the functional TPU films on the first and second plastic films prior to lamination. After several hours, a strongly bonded functional TPU laminate can be obtained without the need for additional energy or processing. In one example, the first plastic film can be a PC film. In one example, the second plastic film can be the same as or different from the first plastic film. The second plastic film can be a PC film, like the first plastic film, or a PMMA film or other material different from the first plastic film.

[0033] In one embodiment, the first plastic film can be a thermoplastic film to which a functional TPU film is applied. In one example, the functional TPU film can include a photochromic dye, a blue light blocking dye, a UV blocking dye, an IR blocking dye, or any other functional component. Thus, the functional TPU film can provide polarization, color, UV protection, etc.

[0034] In one embodiment, the second plastic film can be a thermoplastic film with a functional TPU film applied thereto. In one example, the functional TPU film can include a photochromic dye, a blue light blocking dye, a UV blocking dye, an IR blocking dye, or any other functional component. Thus, the functional TPU film can provide polarization, color, UV protection, etc.

[0035] In one embodiment, the functional TPU film can be applied to the first and second plastic films by extrusion, coating, and pre-lamination, among others. Each of the first and second plastic films can have a thickness of 20 μm to 10 mm. The functional TPU film can have a thickness of 0.5 μm to 500 μm.

[0036] According to one embodiment, the first plastic film and the second plastic film may each include a photochromic dye, a blue light blocking dye, a UV blocking dye, an IR blocking dye, or any other functional component.

[0037] In one embodiment, the first plastic film and the second plastic film can be the same or different materials, each material being selected from the group including PC, PMMA, TAC, OCO, polyethylene terephthalate (PET), and the like.

[0038] According to one embodiment, the method includes applying isopropyl alcohol (IPA), ethanol, methanol, IPA and water, ethanol and water, or methanol and water to a surface of either or both of the first and second plastic films.

[0039] According to one embodiment, the method includes applying a pressure of between 2 psi and 80 psi during lamination.

[0040] According to one embodiment, lamination may be carried out at room temperature (eg, 25° C.) for a period of 2 hours to 24 hours.

[0041] According to one embodiment, the laminate provides adhesion between the TPU laminate layers in the range of 15 N / inch to 80 N / inch, or more preferably in the range of 20 N / inch to 60 N / inch, or more preferably in the range of 30 N / inch to 50 N / inch.

[0042] Referring now to the figures, the methods described herein are described with respect to Figure 2A. Process 200 provides a flow diagram for creating the flat laminate wafer introduced in Figure 1 without the need for thermal curing, UV curing, etc. Here, the functional TPU film is applied to only one of the first and second plastic films.

[0043] In step 225 of process 200, a first plastic film or first plastic substrate having a front surface and a back surface can be provided. In one embodiment, the first plastic film can be PC, PMMA, TAC, OCO, PET, polyamide, nylon, allyl diglycol carbonate, thio-urethane copolymer, polyacrylate, polyepisulfide, polyepoxy, polyamide, or a combination thereof.

[0044] In sub-process 230 of process 200, the front surface of the first plastic film or the back surface of the first plastic film can be treated. In one embodiment, the treatment can include the application of a functional film and / or a photochromic film that provides additional optical qualities, such as polarization under specific wavelengths. The functional film and / or photochromic film can be applied to the front surface of the first plastic film or the back surface of the first plastic film by extrusion, coating, pre-lamination, etc. In one embodiment, the treatment can include the application of an activator to the front surface of the first plastic film or the back surface of the first plastic film. In one embodiment, the treatment can include the application of an activator to the applied functional film and / or photochromic film. The activator can be, in one example, alcohol similar to that used to disinfect medical devices. Sub-process 230 of process 200 is described in more detail with respect to FIG. 2B.

[0045] In step 235 of process 200, a second plastic film or substrate having a front and back surface may be provided and laminated with the treated surface of the first plastic film. In one embodiment, the second plastic film may be PC, PMMA, TAC, OCO, PET, polyamide, nylon, allyl diglycol carbonate, thiourethane copolymer, polyacrylate, polyepisulfide, polyepoxy, polyamide, or a combination thereof.

[0046] According to one embodiment, lamination can be carried out at room temperature (e.g., 25°C) under a pressure of 2 psi to 80 psi, more preferably 2 psi to 30 psi. Pressure can be applied to ensure contact between the juxtaposed surfaces of the treated first and second plastic films. Pressure can be maintained for the time necessary to achieve lamination. For example, lamination times can be from 2 hours to 24 hours. However, it can be appreciated that lamination times can be outside the time ranges specified above, depending on the specific materials involved and their particular chemistries.

[0047] After lamination in step 235 of process 200, the adhesion between the layers of the functional laminate can be evaluated. In one example, it can be appreciated that the functional laminate may have an adhesive strength or adhesion level when measured by a pull-off adhesion test of 5 N / inch to 80 N / inch, or any range and value therebetween, including 5 N / inch to 10 N / inch, 10 N / inch to 15 N / inch, 15 N / inch to 20 N / inch, 20 N / inch to 25 N / inch, 25 N / inch to 30 N / inch, 30 N / inch to 35 N / inch, 35 N / inch to 40 N / inch, 40 N / inch to 45 N / inch, and 45 N / inch to 50 N / inch, 50 N / inch to 55 N / inch, 55 N / inch to 60 N / inch, 60 N / inch to 65 N / inch, 65 N / inch to 70 N / inch, 70 N / inch to 75 N / inch, and 75 N / inch to 80 N / inch. Preferably, the adhesive strength of the functional laminate is greater than 20 N / inch.

[0048] Referring now to FIG. 2B, sub-process 230 of process 200 is described in more detail.

[0049] In step 231 of subprocess 230, a polyurethane resin, acting as a functional film and / or a photochromic film, can be applied to the front or back surface of the first plastic film. To provide additional optical quality, the polyurethane resin can include a dye. The dye can be one of a photochromic dye, a dichroic dye, a blue-blocking dye, an infrared-blocking dye, an ultraviolet-blocking dye, a selective wavelength-blocking dye, a color-enhancing dye, a light-filtering dye, or a combination thereof. When applied, the polyurethane resin can have a thickness of 0.5 μm to 500 μm. In one embodiment, the polyurethane resin can be a polyester polyurethane resin, a polyether polyurethane resin, or a polycaprolactone resin.

[0050] In step 232 of subprocess 230, an activator can be applied to the polyurethane resin applied onto the surface of the first plastic film. As previously mentioned, the activator can be, in one example, an alcohol similar to that used to disinfect medical devices. The activator can advantageously be a material that removes debris from the surface of the polyurethane resin. Application of the activator can be performed as a wipe or rinse, with at least a portion of the remaining activator being removed by evaporation or a similar method prior to lamination.

[0051] According to one embodiment, the activator can be a combination of alcohol and water. The combination of alcohol and water ensures that at least a portion of the activator remains between the laminate. Thus, the activator includes water to reduce air pockets that form between the surfaces of the first and second plastic films during lamination. In one embodiment, the activator can be pure alcohol, and water can be applied after application of the activator to reduce air pockets that form between the surfaces of the first and second plastic films during lamination.

[0052] According to one embodiment, the activator may be IPA, ethanol and methanol, or a combination of IPA and water, ethanol and water, or methanol and water, among others. In one embodiment, the activator is IPA containing 60% to 90% v / v alcohol in purified water.

[0053] In one embodiment, the treatment of the first plastic film described in subprocess 230 of process 200 may enable the formation of hydrogen bonds at the interface between the first plastic film and the second plastic film in step 235 of process 200. The improved hydrogen bonding between the first plastic film and the second plastic film, which may be based on the purity of the polyurethane resin, results in improved adhesion between the first plastic film and the second plastic film compared to laminates produced using conventional methods.

[0054] 2A and 2B. The surface of a first plastic film 311 may be treated in subprocess 230 of process 200. This treatment may include, for example, applying a functional film and / or photochromic film 320 to the surface of the first plastic film 311. The treated surface of the first plastic film 311 may be juxtaposed with the surface of a second plastic film 312. In step 235 of process 200, the juxtaposition may be performed under pressure to laminate the first plastic film 311, the functional film and / or photochromic film 320, and the second plastic film 312.

[0055] The above method applies a functional film and / or photochromic film to the surface of either the first plastic film or the second plastic film. It can be appreciated, therefore, that by applying a functional film and / or photochromic film to the juxtaposed surfaces of both the first and second plastic films, the adhesion therebetween can be altered. While the adhesion achieved during the lamination process of Figures 2A, 2B, and 3 is sufficient for use in lens applications after injection molding or casting, Figures 4A, 4B, and 5 describe lamination processes in which the respective surfaces of the first and second plastic films are treated to tailor their mechanical properties to the needs of a particular task.

[0056] Referring now to FIG. 4A, process 400 shows a flow diagram for making the flat laminate wafer introduced in FIG. 1 in which a functional TPU film is applied to the surface of each of the first and second plastic films without the need for thermal curing, UV curing, etc.

[0057] In step 465 of process 400, a first plastic film or first plastic substrate having a front surface and a back surface can be provided. In one embodiment, the first plastic film can be PC, PMMA, TAC, OCO, PET, polyamide, nylon, allyl diglycol carbonate, thio-urethane copolymer, polyacrylate, polyepisulfide, polyepoxy, polyamide, or a combination thereof.

[0058] In step 470 of process 400, a second plastic film or second plastic substrate having a front surface and a back surface can be provided. In one embodiment, the second plastic film can be PC, PMMA, TAC, OCO, PET, polyamide, nylon, allyl diglycol carbonate, thiourethane copolymer, polyacrylate, polyepisulfide, polyepoxy, polyamide, or a combination thereof.

[0059] In sub-process 475 of process 400, the front surface of the first plastic film or the back surface of the first plastic film can be treated, and the front surface of the second plastic film or the back surface of the second plastic film can be treated. In one embodiment, the treatment can include the application of a functional film and / or a photochromic film that provides additional optical qualities. The functional film and / or the photochromic film can be applied to the front surface of the first plastic film or the back surface of the first plastic film and the front surface of the second plastic film or the back surface of the second plastic film by extrusion, coating, pre-lamination, etc. In one embodiment, the treatment can include the application of an activator to the front surface of the first plastic film or the back surface of the first plastic film and the front surface of the second plastic film or the back surface of the second plastic film. In one embodiment, the treatment can include the application of an activator to the applied functional film and / or photochromic film. The activator can be, in one example, alcohol similar to that used to disinfect medical devices. Sub-process 475 of process 400 is described in more detail with respect to FIG. 4B.

[0060] In step 480 of process 400, lamination of the first and second plastic films may be performed by juxtaposing the treated surfaces of the first and second plastic films.

[0061] According to one embodiment, lamination can be carried out at room temperature (e.g., 25°C) and under a pressure of 2 psi to 80 psi, more preferably 2 psi to 30 psi. Pressure can be applied to ensure contact between the juxtaposed treated surfaces of the first plastic film and the second plastic film. Pressure can be maintained for the time necessary to achieve lamination. For example, lamination times can be 2 hours to 24 hours. However, it can be appreciated that lamination times can be outside the time ranges specified above, depending on the specific materials involved and their particular chemistries.

[0062] After lamination in step 480 of process 400, the adhesion between the layers of the functional laminate can be evaluated. In one example, it can be appreciated that the functional laminate may have an adhesive strength or adhesion level when measured by a pull-off adhesion test of 5 N / inch to 80 N / inch, or any range and value therebetween, including 5 N / inch to 10 N / inch, 10 N / inch to 15 N / inch, 15 N / inch to 20 N / inch, 20 N / inch to 25 N / inch, 25 N / inch to 30 N / inch, 30 N / inch to 35 N / inch, 35 N / inch to 40 N / inch, 40 N / inch to 45 N / inch, and 45 N / inch to 50 N / inch, 50 N / inch to 55 N / inch, 55 N / inch to 60 N / inch, 60 N / inch to 65 N / inch, 65 N / inch to 70 N / inch, 70 N / inch to 75 N / inch, and 75 N / inch to 80 N / inch. Preferably, the adhesive strength of the functional laminate is greater than 20 N / inch.

[0063] Referring now to FIG. 4B, sub-process 475 of process 400 is described in more detail.

[0064] Similar to FIG. 2B, in step 476 of subprocess 475, a polyurethane resin as a functional film and / or photochromic film can be applied to the front or back surface of the first plastic film and the front or back surface of the second plastic film. To provide additional optical quality, the polyurethane resin can include a dye. The dye can be one of a photochromic dye, a dichroic dye, a blue-blocking dye, an infrared-blocking dye, an ultraviolet-blocking dye, a selective wavelength-blocking dye, a color-enhancing dye, a light-filtering dye, or a combination thereof. When applied, the polyurethane resin can have a thickness of 0.5 μm to 500 μm. In one embodiment, the polyurethane resin can be a polyester polyurethane resin, a polyether polyurethane resin, or a polycaprolactone resin.

[0065] In step 477 of sub-process 475, an activator may be applied to the polyurethane resin applied to the surface of the first plastic film and the polyurethane resin applied to the surface of the second plastic film. As previously mentioned, the activator may, in one example, be an alcohol similar to that used to disinfect medical devices. The activator may advantageously be a material that removes debris from the polyurethane resin applied to the surface of the first plastic film and the polyurethane resin applied to the surface of the second plastic film. Application of the activator may be performed as a wipe or rinse, with at least a portion of the remaining activator being removed by evaporation or a similar method prior to lamination.

[0066] According to one embodiment, the activator can be a combination of alcohol and water. The combination of alcohol and water ensures that at least a portion of the activator remains between the laminate. Thus, the activator includes water to reduce air pockets that form between the treated surfaces of the first and second plastic films during lamination. In one embodiment, the activator can be pure alcohol, and water can be applied after application of the activator to reduce air pockets that form between the treated surfaces of the first and second plastic films during lamination.

[0067] According to one embodiment, the activator may be IPA, ethanol and methanol, or a combination of IPA and water, ethanol and water, or methanol and water, among others. In one embodiment, the activator is IPA containing 60% to 90% v / v alcohol in purified water.

[0068] In one embodiment, the treatment of the first and second plastic films described in subprocess 475 of process 400 may enable the formation of hydrogen bonds at the interface between the treated surfaces of the first and second plastic films in step 480 of process 400. The improved hydrogen bonding between the treated surfaces of the first and second plastic films, which may be due to the purity of the polyurethane resin, results in improved adhesion between the first and second plastic films compared to laminates produced using conventional methods.

[0069] Referring now to FIG. 5, an illustration of the flow diagrams of FIGS. 4A and 4B is shown. The surface of the first plastic film 511 may be treated in sub-process 475 of process 400. This treatment may include, for example, applying a functional film and / or photochromic film 520 to the surface of the first plastic film 511 and applying an activator. Similarly, the surface of the second plastic film 512 may be treated in sub-process 475 of process 400. This treatment may include, for example, applying a functional film and / or photochromic film 520′ to the surface of the second plastic film 512 and applying an activator. The treated surface of the first plastic film 511 may be juxtaposed with the treated surface of the second plastic film 512. In step 480 of process 400, the juxtaposition may be performed under pressure to laminate the first plastic film 511, the functional film and / or photochromic film 520, 520′, and the second plastic film 512.

[0070] While the functionality of the functional laminate described above is provided by the polyurethane resin, it can be appreciated that it may be the first plastic film and / or the second plastic film that provides the functionality, or a combination thereof that provides the functionality.

[0071] By practicing the above method, many types of laminates can be produced in a simple manner that does not involve chemical adhesives, heat and / or UV curing.

[0072] As part of this disclosure, specific examples are included below. These examples are for illustrative purposes only and are not intended to limit the present invention. Indeed, these examples may not be exemplary embodiments of the present disclosure, but instead are intended to provide a contrast between non-limiting examples of the present disclosure and other implementations in the field. Those skilled in the art will readily recognize parameters that can be changed or modified to achieve essentially the same results.

[0073] References to "laminating overnight" may generally be described as "drying," as in the case of FIG. 6. "Type of adhesive" may be analogous to "type of activator." Such "drying" may define the drying time as well as the pressure applied during drying. For example, the drying time may be 2 hours to 24 hours, and the applied pressure may be 3 psi to 30 psi. It can be appreciated that the ranges defined above are merely exemplary, and other ranges included or excluded from the above may be implemented to achieve the flat-laminated wafers described in this disclosure. [Example]

[0074] Example 1 (Preparation of Photochromic PC-TPU-TPU-PC Laminates with IPA) Photochromic TPU resin (Pellethane 80A 2363 with photochromic dye from Transitions Inc.) was extruded onto a polycarbonate film to obtain a PC-TPU film roll with a TPU thickness of approximately 150 μm. Wafers with a diameter of 76 mm were then die-cut from this film roll. The two TPU sides of the wafer were then wiped with IPA and then laminated onto each other in the presence of IPA at room temperature (e.g., 25°C) at 30 psi overnight. No heat cure was applied. After approximately 24 hours, a photochromic PC-TPU-TPU-PC laminate wafer was obtained with strong TPU-TPU adhesion and a peel force (i.e., adhesion level) of greater than 50 N / inch (see Figure 6).

[0075] Example 2 (Preparation of Photochromic PC-TPU-TPU-PC Laminates with IPA + Water) The same photochromic TPU resin as in Example 1 was extruded onto a PC film to obtain a PC-TPU film roll. Wafers with a diameter of 76 mm were then die-cut from this film roll. The two TPU surfaces were then wiped with IPA and then laminated onto each other in the presence of water at room temperature (e.g., 25°C) and 30 psi overnight. No heat cure was applied. After approximately 24 hours, a photochromic PC-TPU-TPU-PC laminate wafer was obtained, with strong adhesion between the TPUs and a peel force (i.e., adhesion level) of greater than 25 N / inch (see Figure 6).

[0076] Example 3 (Preparation of photochromic PC-TPU-TPU-PC laminates with methanol) The same photochromic TPU resin as in Example 1 was extruded onto a PC film as a PC-TPU film roll. Wafers with a diameter of 76 mm were then die-cut from this film roll. The TPU surfaces were then wiped with methanol and then laminated onto each other in the presence of methanol at room temperature (e.g., 25°C) and 30 psi overnight. No heat cure was applied. After approximately 24 hours, a photochromic PC-TPU-TPU-PC laminate wafer was obtained with strong TPU-TPU adhesion and a peel force (i.e., adhesion level) of greater than 50 N / inch (see Figure 6).

[0077] Example 4 Preparation of Photochromic PC-TPU-PC Laminates for Injection Molding The same photochromic TPU resin as in Example 1 was extruded onto a PC film to form a PC-TPU film roll. Wafers with a diameter of 76 mm were then die-cut from this film roll. The TPU surface was then wiped with IPA and then laminated onto another PC film in the presence of IPA and water at room temperature (e.g., 25°C) and 30 psi overnight. No heat cure was applied. After approximately 24 hours, a photochromic PC-TPU-PC laminate wafer was obtained. The laminate wafer was then thermoformed onto a 4.0D base wafer using a LEMA machine, which was then injection molded to produce a PC photochromic semi-finished lens with excellent adhesion. No delamination occurred during the surface processing to produce a -2.0D lens.

[0078] Example 5 Preparation of Photochromic TPU-TPU Laminates with PET Release Liners The same photochromic TPU resin as in Example 1 was extruded onto a PET release liner to obtain a TPU film roll. After removal of the liner on one side, two TPU films were wiped with IPA and then laminated onto each other in the presence of IPA at room temperature (e.g., 25°C) and 30 psi overnight. No heat cure was applied. After about 24 hours, a photochromic TPU-TPU laminate wafer was obtained with very strong adhesion and a peel force (i.e., adhesion level) of about 50 N / inch (see Figure 6).

[0079] Comparative Example 1 Preparation of Photochromic TPU-TPU Laminates with Silicone Release Liners The same photochromic TPU resin as in Example 1 was extruded onto a silicone release liner. After removal of the liner, two TPU films were wiped with IPA and then laminated onto each other in the presence of IPA at room temperature (e.g., 25°C) and 30 psi overnight. No heat cure was applied. Due to the presence of silicone traces on the TPU surface, adhesion at the TPU-TPU interface was very poor and exhibited a peel force (i.e., adhesion level) of approximately 0 N / inch.

[0080] Comparative Example 2 (Preparation of photochromic TPU-TPU laminates using water only) The same photochromic TPU resin as in Example 1 was extruded onto a PC film as a PC-TPU film roll. Wafers with a diameter of 76 mm were then die-cut from this film roll. The TPU surfaces were then wiped with water and then laminated onto each other in the presence of water at room temperature (e.g., 25°C) at 30 psi overnight. No heat cure was applied. Due to the presence of water on the TPU surface, adhesion at the TPU-TPU interface was very poor, exhibiting a peel force (i.e., adhesion level) of approximately 0 N / inch (see Figure 6).

[0081] Comparative Example 3 (Preparation of photochromic TPU-TPU laminates by corona treatment + water) The same photochromic TPU resin as in Comparative Example 2 was extruded onto a PC film as a PC-TPU film roll. Wafers with a diameter of 76 mm were then die-cut from this film roll. The TPU surfaces were then corona-treated (for adhesion promotion purposes) and then laminated onto each other in the presence of water at room temperature (e.g., 25°C) at 30 psi overnight. No heat cure was applied. Due to the presence of water on the TPU surface, adhesion at the TPU-TPU interface was very poor, exhibiting a peel force (i.e., adhesion level) of approximately 0 N / inch (see Figure 6).

[0082] Comparative Example 4 (Preparation of photochromic TPU-TPU laminates with IPA and water-based HMA) The same photochromic TPU resin as in Comparative Example 2 was extruded onto a PC film as a PC-TPU film roll. Wafers with a diameter of 76 mm were then die-cut from this film roll. The two TPU surfaces were then wiped with IPA and then laminated onto each other overnight at room temperature (e.g., 25°C) and 30 psi in the presence of a water-based hot melt adhesive (HMA) (UD-104 from Bondpolymer Inc.). No heat cure was applied. Due to the presence of the water-based HMA on the TPU surface, adhesion at the TPU-TPU interface was very poor, exhibiting a peel force (i.e., adhesion level) of approximately 0 N / inch (see Figure 6).

[0083] According to one embodiment, the disclosed method can be implemented within the roll-to-roll manufacturing of photochromic laminates, which can then be used in conventional injection molding processes to produce photochromic semi-finished or finished lenses with high photochromic performance.

[0084] According to one embodiment, the method of the present disclosure can be carried out on a small scale (e.g., in a retail store or laboratory) because the process described does not require heat and / or UV radiation therein.

[0085] According to one embodiment, the method of the present disclosure can be implemented within other film lamination techniques to produce value-added laminates for applications in optical lenses, including clear to polarized laminates, photochromic laminates, or other optically functional laminates, such as optical microstructure laminates.

[0086] Obviously, many modifications and variations are possible in light of the above teachings and it is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

[0087] Embodiments of the present disclosure can also be described in the following description.

[0088] (1) A method for preparing a laminate, comprising: obtaining a first plastic substrate having a front surface and a back surface; treating the front surface of the first plastic substrate or the back surface of the first plastic substrate; and laminating a second plastic substrate onto the treated front surface of the first plastic substrate or the treated back surface of the first plastic substrate.

[0089] (2) The method of (1), wherein the treating comprises applying a polyurethane resin to the front surface of the first plastic substrate or the back surface of the first plastic substrate.

[0090] (3) The method according to either (1) or (2), wherein the applied polyurethane resin is a polyester polyurethane resin, a polyether polyurethane resin, or a polycaprolactone resin.

[0091] (4) Any one of the methods (1) to (3), wherein the applied polyurethane resin contains at least one dye selected from the group consisting of photochromic dyes, dichroic dyes, blue-cutting dyes, infrared-cutting dyes, ultraviolet-cutting dyes, selective wavelength-cutting dyes, color-enhancing dyes, and light-filtering dyes.

[0092] (5) Any one of the methods (1) to (4), wherein the applied polyurethane resin has a thickness of 0.5 microns to 500 microns.

[0093] (6) Any one of the methods (1) to (5), wherein the treatment comprises applying isopropyl alcohol or methanol in combination with water to the applied polyurethane resin.

[0094] (7) Any one of the methods (1) to (5), wherein the treating comprises applying isopropyl alcohol, ethanol, or methanol to the applied polyurethane resin, preferably, the treating comprises applying isopropyl alcohol in combination with water, ethanol in combination with water, or methanol in combination with water to the applied polyurethane resin.

[0095] (8) Any one of the methods (1) to (7), wherein the lamination is performed at room temperature.

[0096] (9) Any one of methods (1) to (8) in which lamination is performed at 2 to 30 psi.

[0097] (10) The method of any one of (1) to (9), wherein the first plastic substrate comprises at least one selected from the group consisting of polycarbonate, cellulose triacetate, polymethyl methacrylate, polyamide, polyethylene terephthalate, cyclic olefin copolymer, nylon, allyl diglycol carbonate, thiourethane copolymer, polyacrylate, poly-episulfide, polyepoxy, and polyamide.

[0098] (11) The method of any one of (1) to (10), wherein the second plastic substrate comprises at least one selected from the group consisting of polycarbonate, cellulose triacetate, polymethyl methacrylate, polyamide, polyethylene terephthalate, cyclic olefin copolymer, nylon, allyl diglycol carbonate, thiourethane copolymer, polyacrylate, poly-episulfide, polyepoxy, and polyamide.

[0099] (12) Any one of the methods (1) to (11), wherein the treatment of the front surface of the first plastic substrate or the back surface of the first plastic substrate enables the formation of hydrogen bonds at the interface between the treated surfaces of the first plastic substrate and the second plastic substrate.

[0100] (13) Any one of the methods (1) to (12), wherein the resulting first plastic substrate and second plastic substrate each have a thickness of 20 microns to 10 millimeters.

[0101] (14) The method of any one of (1) to (13), further comprising treating the front surface of the second plastic substrate or the back surface of the second plastic substrate, wherein the lamination comprises juxtaposing the treated front surface of the first plastic substrate or the treated back surface of the first plastic substrate and the treated front surface of the second plastic substrate or the treated back surface of the second plastic substrate.

[0102] (15) The method of any one of (1) to (14), wherein the treating comprises applying a polyurethane resin to the front surface of the first plastic substrate or the back surface of the first plastic substrate, applying a polyurethane resin to the front surface of the second plastic substrate or the back surface of the second plastic substrate, and applying isopropyl alcohol or methanol in combination with water to the applied polyurethane resin of the first plastic substrate and the applied polyurethane resin of the second plastic substrate.

[0103] (16) Any one of the methods (1) to (15), wherein the polyurethane resin contains at least one dye selected from the group consisting of photochromic dyes, dichroic dyes, blue-cutting dyes, infrared-cutting dyes, ultraviolet-cutting dyes, selective wavelength-cutting dyes, color-enhancing dyes, and light-filtering dyes.

[0104] Thus, the foregoing discussion discloses and describes merely exemplary embodiments of the present invention. As will be understood by those skilled in the art, the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the disclosure of the present invention is intended as an illustration, not a limitation, of the scope of the invention and other claims. The disclosure, including all readily discernible variations of the teachings herein, defines in part the scope of the following claim terms so that the spirit of the invention is not dedicated to the public. The present disclosure includes the following inventive aspects: <Aspect 1> Obtaining a first plastic substrate having a front surface and a back surface; treating the front surface of the first plastic substrate or the back surface of the first plastic substrate; laminating a second plastic substrate onto the treated front surface of the first plastic substrate or onto the treated back surface of the first plastic substrate; A method for preparing a laminate, comprising: <Aspect 2> 2. The method of claim 1, wherein the treating comprises applying a polyurethane resin to the front surface of the first plastic substrate or the back surface of the first plastic substrate. <Aspect 3> 3. The method of claim 2, wherein the applied polyurethane resin is a polyester polyurethane resin, a polyether polyurethane resin, or a polycaprolactone resin. <Aspect 4> 3. The method of claim 2, wherein the applied polyurethane resin contains at least one dye selected from the group consisting of photochromic dyes, dichroic dyes, blue-blocking dyes, infrared-blocking dyes, ultraviolet-blocking dyes, selective wavelength-blocking dyes, color-enhancing dyes, and light-filtering dyes. <Aspect 5> 3. The method of embodiment 2, wherein the applied polyurethane resin has a thickness of from 0.5 microns to 500 microns. <Aspect 6> 3. The method of claim 2, wherein the treating comprises applying isopropyl alcohol, ethanol, or methanol to the applied polyurethane resin; preferably, the treating comprises applying isopropyl alcohol in combination with water, ethanol in combination with water, or methanol in combination with water to the applied polyurethane resin. <Aspect 7> The method of embodiment 1, wherein the laminating is performed at room temperature. <Aspect 8> The method of embodiment 1, wherein the lamination is performed at 2 to 30 psi. <Aspect 9> 2. The method of claim 1, wherein the first plastic substrate comprises at least one selected from the group consisting of polycarbonate, cellulose triacetate, polymethyl methacrylate, polyamide, polyethylene terephthalate, cyclic olefin copolymer, nylon, allyl diglycol carbonate, thiourethane copolymer, polyacrylate, poly-episulfide, polyepoxy, and polyamide. <Aspect 10> 2. The method of claim 1, wherein the second plastic substrate comprises at least one selected from the group consisting of polycarbonate, cellulose triacetate, polymethyl methacrylate, polyamide, polyethylene terephthalate, cyclic olefin copolymer, nylon, allyl diglycol carbonate, thiourethane copolymer, polyacrylate, poly-episulfide, polyepoxy, and polyamide. <Aspect 11> 2. The method of embodiment 1, wherein the treatment of the front surface of the first plastic substrate or the back surface of the first plastic substrate enables the formation of hydrogen bonds at the interface between the treated surfaces of the first plastic substrate and the second plastic substrate. <Aspect 12> 2. The method of claim 1, wherein the resulting first plastic substrate and the second plastic substrate each have a thickness of between 20 microns and 10 millimeters. <Aspect 13> Treating the front surface of the second plastic substrate or the back surface of the second plastic substrate. further comprising 2. The method of claim 1, wherein the laminating comprises juxtaposing the treated front surface of the first plastic substrate or the treated back surface of the first plastic substrate and the treated front surface of the second plastic substrate or the treated back surface of the second plastic substrate. <Aspect 14> The process comprises: applying a polyurethane resin to the front surface of the first plastic substrate or the back surface of the first plastic substrate; applying a polyurethane resin to the front surface of the second plastic substrate or the back surface of the second plastic substrate; applying isopropyl alcohol or methanol in combination with water to the applied polyurethane resin of the first plastic substrate and the applied polyurethane resin of the second plastic substrate; 14. The method of embodiment 13, comprising: <Aspect 15> 15. The method of claim 14, wherein the polyurethane resin comprises at least one dye selected from the group consisting of photochromic dyes, dichroic dyes, blue-cutting dyes, infrared-cutting dyes, ultraviolet-cutting dyes, selective wavelength-cutting dyes, color-enhancing dyes, and light-filtering dyes.

Claims

1. Obtaining a first plastic substrate having a front surface and a back surface; treating the front surface of the first plastic substrate or the back surface of the first plastic substrate; laminating a second plastic substrate onto the treated front surface of the first plastic substrate or onto the treated back surface of the first plastic substrate; A method for preparing a laminate, comprising:

2. The method of claim 1 , wherein the treating comprises applying a polyurethane resin to the front surface of the first plastic substrate or the back surface of the first plastic substrate.

3. The method of claim 2, wherein the applied polyurethane resin is a polyester polyurethane resin, a polyether polyurethane resin, or a polycaprolactone resin.

4. 3. The method of claim 2, wherein the applied polyurethane resin contains at least one dye selected from the group consisting of photochromic dyes, dichroic dyes, blue-cutting dyes, infrared-cutting dyes, ultraviolet-cutting dyes, selective wavelength-cutting dyes, color-enhancing dyes, and light-filtering dyes.

5. The method of claim 2, wherein the applied polyurethane resin has a thickness of from 0.5 microns to 500 microns.

6. 3. The method of claim 2, wherein the treatment comprises applying isopropyl alcohol, ethanol, or methanol to the applied polyurethane resin, preferably the treatment comprises applying isopropyl alcohol in combination with water, ethanol in combination with water, or methanol in combination with water to the applied polyurethane resin.

7. The method of claim 1 , wherein the lamination is performed at room temperature.

8. The method of claim 1 wherein the lamination is performed at 2 to 30 psi.

9. 10. The method of claim 1, wherein the first plastic substrate comprises at least one selected from the group consisting of polycarbonate, cellulose triacetate, polymethyl methacrylate, polyamide, polyethylene terephthalate, cyclic olefin copolymer, nylon, allyl diglycol carbonate, thiourethane copolymer, polyacrylate, poly-episulfide, polyepoxy, and polyamide.

10. 10. The method of claim 1, wherein the second plastic substrate comprises at least one selected from the group consisting of polycarbonate, cellulose triacetate, polymethyl methacrylate, polyamide, polyethylene terephthalate, cyclic olefin copolymer, nylon, allyl diglycol carbonate, thiourethane copolymer, polyacrylate, poly-episulfide, polyepoxy, and polyamide.

11. 10. The method of claim 1, wherein the treatment of the front surface of the first plastic substrate or the back surface of the first plastic substrate enables the formation of hydrogen bonds at the interface between the treated surfaces of the first plastic substrate and the second plastic substrate.

12. 10. The method of claim 1, wherein the resulting first plastic substrate and the second plastic substrate each have a thickness of between 20 microns and 10 millimeters.

13. Treating the front surface of the second plastic substrate or the back surface of the second plastic substrate. further comprising 10. The method of claim 1, wherein the laminating comprises juxtaposing the treated front surface of the first plastic substrate or the treated back surface of the first plastic substrate and the treated front surface of the second plastic substrate or the treated back surface of the second plastic substrate.

14. The process applying a polyurethane resin to the front surface of the first plastic substrate or the back surface of the first plastic substrate; applying a polyurethane resin to the front surface of the second plastic substrate or the back surface of the second plastic substrate; applying isopropyl alcohol or methanol in combination with water to the applied polyurethane resin of the first plastic substrate and the applied polyurethane resin of the second plastic substrate; 14. The method of claim 13, comprising:

15. 15. The method of claim 14, wherein the polyurethane resin comprises at least one dye selected from the group consisting of photochromic dyes, dichroic dyes, blue-cutting dyes, infrared-cutting dyes, ultraviolet-cutting dyes, selective wavelength-cutting dyes, color-enhancing dyes, and light-filtering dyes.

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