Patent Description:
Added functions, such as light filtering or optical functions, can be integrated into an ophthalmic lens through the incorporation of a functional element such as films, wafers or laminates.

One of the problems associated with integrating a thermoplastic-based functional element into an ophthalmic thermoset lens is compatibility of the thermoplastic functional element with the lens casting material, or surrounding lens substrate. The functional element should not be damaged by the lens casting material and should have good adhesion. Compatibility issues may arise during the manufacturing process, during the finishing process, or during use. During the manufacturing process, it is highly desirable to develop some level of connectivity to the casting monomer. A strong adhesive bond can help to, for instance, improve component output and efficiency. During the finishing process, it is highly desirable to have some level of connectivity to the cast resin. Lens finishing processing steps include lens blocking, cribbing, back curve generation, back curve fining and polishing, lens edging, and deblocking. These processing steps can impart a high level of stress on a lens and can cause delamination of a functional element. There is a need to provide the customer with an ophthalmic lens having good adhesion and optical clarity.

Current cast CR39® polarizing lenses are manufactured using fragile polyvinyl alcohol (PVA) polarizing films with a thickness of approximately <NUM>. These thin polarizing films are susceptible to damage during handling. For instance, during the production of polarized lenses, many manual handling steps are required, which increases the potential for damage.

To this end, PVA films may be laminated within more durable films, such as triacetyl cellulose (TAC). A primer is applied onto the polarizing laminate for good adhesion in cast CR39® lenses, resulting in a more robust TAC/PVA/TAC polarizing element that provides improved handling durability over a single-layer of PVA film. Current industrial primers, however, when used with polycarbonate/PVA/polycarbonate laminates, can damage the optical quality of the polycarbonate (PC) polarizing laminate and do not provide adequate adhesion and may haze the laminate, thereby hindering manufacturing processes. Despite advancements in the field of polarizing film adhesive primers, there is a need for primers that offer improved adhesion and are functionally sound during manufacturing and finishing and across a variety of lens substrates. Such a primer will enable the production of robust functional elements that are capable of being universally applied within ophthalmic lenses.

The foregoing "Background" description is for the purpose of generally presenting the context of the disclosure. Work of the inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present disclosure.

<CIT> is a comparative example lacking any disclosure involving alkoxysilane as a primer component, and the combination of a cationic photoinitiator together with a free radical photoinitiator as an photoactive catalyst.

The present disclosure relates to an ophthalmic lens.

According to an embodiment, the present disclosure further relates to an ophthalmic lens according to claim <NUM>.

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

The terms "about" and "approximately" are defined as being close to as understood by one of ordinary skill in the art.

The terms "laminate" and "laminated lens" or variations of these terms, when used in the claims and/or the specification, refer to a similar structure.

The terms "inhibiting" or "reducing" or "preventing" or "avoiding" or any variation of these terms, when used in the claims and/or the specification, includes any measurable decrease or complete inhibition to achieve a desired result.

The process of the present disclosure can "comprise," "consist essentially of," or "consist of' particular ingredients, components, compositions, etc., disclosed throughout the specification.

The terms "primer" and "primer coating" may be used interchangeably in the specification and/or the claims, but are intended to convey the same or similar materials.

The terms "functional component" and "functional element" may be used interchangeably in the specification and/or claims, but are intended to convey the same or similar materials. The term "functional component" or "functional element" may be used as a high-level term to refer to, as appropriate for given embodiments, each of (<NUM>) a thermoplastic layer, (<NUM>) a thermoplastic layer and a functional layer, and (<NUM>) a thermoplastic layer, a functional layer, and a thermoplastic layer.

The present disclosure relates to an ophthalmic lens featuring a lens substrateindependent primer for adhering a functional element to one or more lens substrates, wherein the functional element may be one of a film, a wafer, or a laminate.

This is particularly important as certain light filtering systems and optical functions of functional elements, such as color enhancement, polarization, blue light filtering, near infrared filtering, photochromic properties, and myopia defocus, among others, which have been established in polycarbonate (PC) lens substrates, are not readily available for use with thermoset lens substrates. For instance, functional elements that include polycarbonate films can be damaged by a thermoset lens substrate precursor during casting, resulting in reduced adhesion and a visibly-attacked and hazy ophthalmic lens. Therefore, it can be appreciated that significant development time is required to devise a solution where the light filters are compatible with the surrounding monomer host, or lens substrate precursor. Moreover, as thermoset lens substrates are prevalent in lens production, a technical solution where innovations in functional elements made for PC lens substrates could be readily implemented in thermoset lens substrates is of a great interest.

The introduction of functional elements having light filtering and/or optical functions within a lens substrate requires consideration of compatibility between the functional element and the surrounding host, or lens substrate, to achieve the desired performance. To this end, one approach incorporates the functional element within the lens substrate by arranging the functional element within a casting mold prior to addition of a lens substrate precursor. As an alternative to placing functional elements of triacetyl cellulose and polyvinyl alcohol inside of the casting cavity, which can be considered a lens substrate specific solution, a thermoplastic functional element including PC films may be placed inside of the casting cavity prior to addition of the lens substrate precursor, the intent thereof to provide a generally-applicable PC-based functional element that can be applied in a variety of lens substrate systems. However, even though adhesion between the PC-based functional element and the lens substrate may be adequate, because the lens substrate precursor is a monomer of CR39®, the PC-based functional element is degraded by contact with the CR39® lens substrate precursor. Degradation can lead to, among other things, haziness and lack of visual clarity.

Accordingly, an exemplary embodiment of the present disclosure describes primers that provide protection to the functional element and promote adhesion between the functional element and a thermoset lens substrate (via a thermoset lens substrate precursor). For instance, the primers may include an ultraviolet (UV)-curable epoxy- and acrylate-based primer.

According to an embodiment, the primer may be applied to one or more surfaces of a PC-based functional element and adhered to a corresponding one or more thermoset lens substrate, or one or more thermoset monomer.

According to an embodiment, the present disclosure describes a PC-based functional element treatment that prepares and protects surfaces of the PC-based functional element for contact with a thermoset lens substrate precursor.

The ophthalmic lens of the present disclosure provides benefits including (<NUM>) constant and homogenous light filtering performance across a variety of lens substrate materials (e.g., thermoplastic lens substrates, thermoset lens substrates), and (<NUM>) decreased complexity of manufacturing in handling multiple types of functional element and different lens substrate materials by using a single, generally-compatible functional element design.

Turning now to the Figures, <FIG> provides a cross-sectional schematic of a functional element <NUM> within a casting mold <NUM>. The functional element <NUM> may comprise a resin that includes a light filter that imparts visual properties and optical functionality on the functional element <NUM>. For instance, the dye may be one of a photochromic dye, a dichroic dye, a blue cut dye, an infrared cut dye, a UV cut dye, a selective wavelength cut dye, a color enhancement dye, or a combination thereof, among others. The functional element <NUM> may be a thickness of between <NUM> and <NUM>. In an embodiment, the functional element <NUM> may include at least one thermoplastic film, or at least one thermoplastic layer. The at least one thermoplastic film may be one of a PC film, a triacetyl cellulose (TAC) film, and a polyamide (PA) film, among others. In an embodiment, the casting mold <NUM> is substantially cylindrical.

In an embodiment, the casting mold <NUM> includes a gasket <NUM> and a first casting insert <NUM> and a second casting insert <NUM>. The first casting insert <NUM> and the second casting insert <NUM> may define, therebetween, at least one void. During casting, the at least one void may be filled with lens substrate monomer. In an example, a desired ophthalmic lens may include a functional element having a lens substrate on either surface of the functional element. Such an instance reflects the schematic of <FIG>. In this example, the at least one void may be a first void <NUM> and a second void <NUM>, and lens substrate monomer may fill the first void <NUM> and the second void <NUM> in order to prepare the desired ophthalmic lens, a curvature of the lens substrates being defined by a curvature of the first casting insert <NUM> and a curvature of the second casting insert <NUM>. In another example, a desired ophthalmic lens may include a functional element having a lens substrate on only a single surface of the functional element. In this example, the functional element may abut either of the first casting insert <NUM> or the second casting insert <NUM> and the at least one void may be either of the first void <NUM> or the second void <NUM>. The lens substrate monomer may fill the first void <NUM> or the second void <NUM> in order to prepare the desired ophthalmic lens, and a curvature of the lens substrate may be defined by either the first casting insert <NUM> or the second casting insert <NUM>.

In an embodiment, the lens substrate monomer may be thermoset polyurethane, allyl diglycol carbonate, polythiourethane, episulfur polymers, epoxy, poly(meth)acrylates, polythiomethacrylates, or combinations thereof. The lens substrate of the ophthalmic lens may be a thermoset lens substrate.

In an embodiment, the curvature of the first casting insert <NUM> and the curvature of the second casting insert <NUM> may determine a lens power of an ophthalmic lens. For a semi-finished (SF) lens, a curvature along a convex side of the SF lens is fixed and a curvature along a concave side of the SF lens may be modified after casting by, for example, grinding and polishing.

In an embodiment, and prior to placement in the casting mold <NUM> and ophthalmic lens integration, the functional element <NUM> may be a flat functional element and can be thermoformed into a spherical dome shape of the thermoformed functional element <NUM> via, for example, a thermoforming machine. During thermoforming, the flat functional element can be placed onto a heated thermoforming insert, and a vacuum force can be applied to secure the flat functional element to the thermoforming insert. By adjusting a temperature of the applied heat and a force of the applied vacuum, the flat functional element can be formed to the curved shape of the thermoforming insert to produce the thermoformed functional element <NUM>.

In an embodiment, thermoforming a flat functional element can produce a curved structure and define a curvature of either or both surfaces of the functional element.

According to an embodiment, the functional element <NUM> of <FIG>, in order to improve adherence between the functional element <NUM> and the lens substrate monomer, as introduced above, the functional element <NUM> may be treated by a primer coating on at least one surface of the functional element <NUM>.

Though subsequent Figures will describe methods of applying the primer coating, <FIG> introduces illustrations of a variety of treated functional elements.

For instance, <FIG> describes a functional element <NUM> comprising a single thermoplastic film <NUM>. The single thermoplastic film <NUM> may include a primer coating <NUM> on a concave surface <NUM> of the functional element <NUM>. The at least one thermoplastic film <NUM> may be one of a PC film, a TAC film, and a PA film, among others.

<FIG> describes a functional element <NUM> comprising a thermoplastic film <NUM> and a functional film <NUM>. The functional element <NUM> may include a primer coating <NUM> on a concave surface <NUM> of the thermoplastic film <NUM> of the functional element <NUM>. The at least one thermoplastic film <NUM> may be a one of a PC film, a TAC film, and a PA film, among others. The functional film <NUM> may be one of a polyvinyl alcohol (PVA) film, a thermoplastic polyurethane (TPU) film, and a polyether block amide (PEBA) film, among others. In an example, the at least one thermoplastic film <NUM> and/or the functional film <NUM> may comprise a resin that includes a light filter that imparts visual properties and optical functionality on the functional element <NUM>. The functional element <NUM> may be a PVA/PC functional element, a PVA/TAC functional element, or a PVA/PA functional element, among others. In another example, the dye is a photochromic dye within the functional film <NUM>, and the functional film <NUM> is either of a PEBA film or a TPU film. The functional element <NUM> derived therefrom may be a TPU/PC functional element, a TPU/TAC functional element, a PEBA/TAC functional element, a TPU/PA functional element, or a PEBA/PA functional element, among others. The functional element <NUM> may have a thickness of between <NUM> and <NUM> after lamination of the functional film <NUM> with the at least one thermoplastic film <NUM>.

<FIG> describes a functional element <NUM> comprising a first thermoplastic film <NUM>', a functional film <NUM>, and a second thermoplastic film <NUM>". The functional element <NUM> may include a primer coating <NUM> on a concave surface <NUM> of the first thermoplastic film <NUM>' of the functional element <NUM> or on a convex surface <NUM> of the second thermoplastic film <NUM>" of the functional element <NUM>. In an example, the functional element <NUM> may include the primer coating <NUM> on both of the concave surface <NUM> of the first thermoplastic film <NUM>' of the functional element <NUM> and on the convex surface <NUM> of the second thermoplastic film <NUM>" of the functional element <NUM>. The first thermoplastic film <NUM>' and/or the second thermoplastic film <NUM>" may be a one of a PC film, a TAC film, and a PA film, among others. The functional film <NUM> may be one of a polyvinyl alcohol (PVA) film, a thermoplastic polyurethane (TPU) film, and a polyether block amide (PEBA) film, among others. In an example, one or more of the first thermoplastic film <NUM>', the functional film <NUM>, and the second thermoplastic film <NUM>" may comprise a resin that includes a light filter that imparts visual properties and optical functionality on the functional element <NUM>. The functional element <NUM> may be a PC/PVA/PC functional element, a TAC/PVA/TAC functional element, or a PA/PVA/PA functional element, among others. In another example, the dye is a photochromic dye within the functional film <NUM>, and the functional film <NUM> is either of a PEBA film or a TPU film. The functional element <NUM> derived therefrom may be a PC/TPU/PC functional element, a TAC/TPU/TAC functional element, a TAC/PEBA/TAC functional element, a PA/TPU/PA functional element, or a PA/PEBA/PA functional element, among others. The functional element <NUM> may have a thickness of between <NUM> and <NUM> after lamination of the functional film <NUM> with the first thermoplastic film <NUM>' and the second thermoplastic film <NUM>".

Turning now to FIG. 3A and <FIG>, and as described in <FIG>, the casting mold may include one or more voids according to a lens substrate design of an ophthalmic lens. 3A and <FIG> describe a method of preparing an ophthalmic lens in view of these one or more voids and according to an exemplary embodiment of the present disclosure. It can be appreciated that the functional elements described above with reference to <FIG> may each be implementations of the flow diagrams of FIG. 3A and <FIG>.

With reference to FIG. 3A, method <NUM> is a high level, generalized flow diagram for preparing an ophthalmic lens having a functional element adhered to one or more lens substrates, wherein the adherence is facilitated by treatment of one or more surfaces of the functional element.

At step <NUM> of method <NUM> and in view of <FIG>, a functional element having a convex surface and a concave surface may be provided.

At sub process <NUM> of method <NUM>, one or more of the convex surface and the concave surface of the functional element may be treated. Treatment may include application of a primer to the one or more of the convex surface and the concave surface of the functional element. Sub process <NUM> of method <NUM> will be described in further detail with reference to <FIG> and subsequent Figures.

At sub process <NUM> of method <NUM>, the treated functional element may be adhered to one or more lens substrates. The adherence may include forming the one or more lens substrates from a lens substrate precursor within one or more voids of a casting mold, as shown in <FIG>.

In adhering the treated functional element to the one or more lens substrates, and with reference now to <FIG>, the treated functional element may be adhered to one or more lens substrates at sub process <NUM> of method <NUM>. At step <NUM> of sub process <NUM>, the treated functional element may be arranged within a casting mold according to a desired design of an ophthalmic lens. For instance, the treated functional element may be arranged such that one or more voids remain. At step <NUM> of sub process <NUM>, the one or more voids may be filled with a lens substrate precursor (or monomer). The lens substrate precursor may be uncured thermoset polymer such as a CR39® lens substrate precursor. Following injection of the lens substrate precursor into the one or more voids of the casting mold, the lens substrate precursor may be allowed to cure to a desired hardness, at step <NUM> of sub process <NUM>, prior to removal of the ophthalmic lens from the casting mold. It can be appreciated that sub process <NUM> of method <NUM> is consistent for each of the remaining embodiments of the present disclosure, and as such, description with reference to subsequent Figures will be omitted for brevity.

With reference now to <FIG>, description of an exemplary embodiment of the present disclosure is provided, wherein a functional element including a first thermoplastic film, a functional film, and a second thermoplastic film, is adhered to a single lens substrate on one surface of the functional element.

At step <NUM> of method <NUM>, a functional element having a convex surface and a concave surface may be provided.

At sub process <NUM> of method <NUM>, either the convex surface or the concave surface of the functional element may be treated. Treatment may include application of a primer to either the convex surface or the concave surface of the functional element. Sub process <NUM> of method <NUM> will be described in further detail with reference to <FIG>.

At sub process <NUM> of method <NUM>, the treated functional element may be adhered to a lens substrate in a similar manner to that of <FIG>. The adherence may include forming the lens substrate from a lens substrate precursor within a void of a casting mold and in contact with a surface of the functional element, as shown in <FIG>.

With reference now to <FIG>, sub process <NUM> of method <NUM> describes treatment of either the convex surface or the concave surface of the functional element. At step <NUM> of sub process <NUM>, a primer coating may be applied to either the convex surface or the concave surface of the functional element.

In an embodiment, the primer coating may be one of a plurality of primers that provide robust adhesion between the functional element and the lens substrate. The primers may be formulated to include components that promote bonding to the functional element and the lens substrate. While conventional primers rely on relatively weak primer-primer and primer-substrate electrostatic forces for adhesion, the primers of the present disclosure may bind to the surfaces to which they are applied. The net result of the primers is enhanced adhesive strength and durability.

According to an embodiment, the primers disclosed herein are particularly useful for adhering a functional element including a PC film to a cast CR39® lens substrate. The primers may be designed to provide a level of penetration into a surface of the PC film of the functional element or other element layer. The PC film-penetrating quality of the primers contributes to its adhesive properties.

According to the invention, a primer as disclosed herein includes at least one first reactive monomer, at least one second reactive monomer, and at least one photoactivatable catalyst. In an embodiment, the primer further includes a solvent. The at least one first reactive monomer may be a mixture of at least one acrylic monomer selected from the group consisting of monoacrylate monomers and diacrylate monomers and at least one acrylate monomer selected from the group consisting of triacrylate monomers through hexaacrylate monomers. In an example, a reactive group of the at least one second reactive monomer may be an epoxy. The at least one second reactive monomer may be an epoxy monomer selected from glycidylethers of polyhydric alkanols. The at least one photoactivatable catalyst may be a light-activated catalyst. The light may be a UV light. The at least one photoactivatable catalyst is a cationic catalyst and may be selected from the group consisting of aromatic onium salts and iron arene salt complexes. According to the invention, the primer further includes, as a component of the photoactivatable catalyst, a free radical photoinitiator. The free radical photoinitiator may be one selected from the group consisting of benzophenone and acetophenone.

In an example, the at least one first reactive monomer may be an at least one monomer that is capable of reacting with a lens substrate monomer, or lens substrate precursor. The at least one monomer may be included in an amount of between <NUM> wt. % and <NUM> wt. %, and preferably between <NUM> wt. % and <NUM> wt. % based on a total weight of the at least one second reactive monomer and the at least one monomer present in the composition. In an embodiment, the at least one monomer may be a mixture of acrylate monomers.

According to an embodiment, the at least one second reactive monomer may have a molecular weight of between about <NUM> and <NUM>,<NUM>. The at least one second reactive monomer may be included in an amount of between <NUM> wt. % and <NUM> wt. %, and preferably between <NUM> wt. % and <NUM> wt. %, based on a total weight of the at least one second reactive monomer and the at least one first reactive monomer. In an embodiment, the at least one second reactive monomer may be a mixture of epoxy resin and cycloaliphatic epoxy. According to the invention, the at least one second reactive monomer is an alkoxysilane such as allyltrimethoxysilane, allyltriethoxysilane, allylmethacrylate, and vinyltrimethoxysilane.

According to an embodiment, the at least photoactivatable catalyst may be included in an amount of between <NUM> wt. % and <NUM> wt. %, and preferably between <NUM> wt. % and <NUM> wt. In an embodiment, the at least one photoactivatable catalyst may be a mixture of a cationic photoinitiator and a free radical photoinitiator.

In an embodiment, the primer may include a curable composition. Of course, a curing process may lead to chemical reactions that alter certain ones of the primer components. In some embodiments, the primer component functional groups may be selected in order to interact with the functional element and to react with the lens substrates with which they will adhere. In this way, a primer composition as disclosed herein can be designed and tuned to provide adhesion for the specific functional element and/or lens substrate target materials.

In some embodiments, a solvent may be used to dissolve the primer components. When present, the solvent may be included in an amount of between <NUM> wt. % and <NUM> wt. In an example, the solvent is an alcohol such as methanol, ethanol, n-propanol, and isopropanol, among others. In another example, the solvent may be one of a ketone, an acetate solvent, acetone, methyl ethyl ketone, ethyl acetate, cyclopentanone and cyclohexanone, and any combination thereof.

According to an embodiment, the at least one first reactive monomer may exhibit the same chemical functionality as the lens substrate monomer. When the at least one first reactive monomer exhibits the same chemical functionality as the lens substrate monomer, the at least one first reactive monomer aids in ensuring compatibility of the primer composition with the polymerized lens substrate monomer, also referred to herein as the lens substrate precursor. In some embodiments, the at least one first reactive monomer has different chemical functionality from the lens substrate polymerized monomer. Moreover, the at least one first reactive monomer may have different chemical functionality from the lens substrate monomer but may still be able to react with the polymerized lens substrate monomer. In this case, the at least one first reactive monomer is selected to include the same reactive functional group as the lens substrate monomer. For example, a lens substrate monomer may primarily consist of allyl diglycol carbonate (i.e. CR39®), and the at least one first reactive monomer may be diallyl ether. Although both lens substrate monomer and at least one first reactive monomer are different compounds, they may react with each other by virtue of their reactive functional group. In some aspects, the at least one first reactive monomer comprises a reactive group functionality of <NUM> or more, and preferably at least <NUM>. Increasing the reactive functionality increases the types of functional groups with which the at least one first reactive monomer can react. In an example, the at least one first reactive monomer may include a reactive group or groups selected from the group consisting of allyl, vinyl, acrylic, thiol, isocyanate, epoxy and amine.

In some embodiments, the at least one second reactive monomer has a reactive functionality of <NUM> or more and preferably <NUM>. Increasing the reactive functionality increases the quantity or types of functional groups with which the at least one second reactive monomer can react. In some embodiments, the at least one second reactive monomer is an epoxy monomer. In some embodiments, the at least one second reactive monomer is a functional (meth)acrylate-based resin.

In some embodiments, the functional element is a polarizing element. The polarizing element may include at least one thermoplastic film and a PVA film as a polarizing layer. The at least one thermoplastic film may be PC. In some embodiments, the ophthalmic lens substrate monomer may be allyl diglycol carbonate. The at least one first reactive monomer of the primer may react with the lens substrate monomer to provide chemical bonds that form the basis of strong adhesion between the functional element and the lens substrate.

According to an embodiment, the primers may be applied to a PC-based functional element by flow coating, spin coating, gravure coating, slot die coating, or other means known to those of skill in the art. For instance, the primer may be applied by draw down board method with Mayer rods, wherein the Mayer rods were wire wound MR#<NUM>, the diameter of the wire determining how the thickness of primer applied. In some aspects, wherein a solvent is included, the applied primer may be dried for a predetermined time, for example, between about <NUM> seconds and about <NUM> minutes at a predetermined temperature ranging, for example, from about <NUM> to about <NUM> in order to remove the solvent from the primer composition. Other drying conditions known to those of skill in the art may be employed to remove the solvent, if employed. According to an embodiment, the applied primer may be allowed to fully or partially dry after application to the functional element.

Table <NUM> and Table <NUM> provide exemplary compositions of the primers described herein. It can be appreciated that the values should be considered approximate and in view of the heretofore described composition ranges.

The applied primer may be exposed to an amount of UV light and/or an increase in temperature sufficient to activate the photoactivatable catalyst and initiate curing of the applied primer.

In an embodiment, at step <NUM> of sub process <NUM>, the primed surface of the functional element may be at least partially cured by exposure to electromagnetic radiation. The electromagnetic radiation may be UV light, infrared light, or visible light, among others. In an example, the electromagnetic radiation is UV light provided by a Heraeus oblelight F300S with a H+ bulb. Power, energy, and exposure time may be selected to optimize curing. Typical, non-limiting curing conditions include about <NUM> feet/min (UVA ~1500mJ/cm<NUM>, ~1200mW/cm<NUM>) to about <NUM> feet/min (500mJ/cm<NUM>, 1100mW/cm<NUM>).

At step <NUM> of sub process <NUM>, the UV-cured primer on the surface of the functional element may be further cured by exposure to heat. In an example, the heat may be applied by an infrared oven. The infrared oven may be heated to <NUM>°F, for instance, and the UV-cured primer on the surface of the functional element may be exposed to the heat for a predetermined time. For instance, the predetermined time may be, for example, between <NUM> seconds and <NUM> seconds, and preferably about <NUM> seconds. Of course, it can be appreciated that the temperature and predetermined time for heating the UV-cured primer on the surface of the functional element may be based on a desired hardness. In certain applications, a less than <NUM>% cured primer may be desired in order to promote adhesion.

In view of the flow diagrams of <FIG> and <FIG>, <FIG> provides an exemplary illustration of method <NUM>, wherein adherence between a functional element <NUM> and a lens substrate <NUM> is shown, the functional element <NUM> including a first thermoplastic film, a functional film, and a second thermoplastic film. In an embodiment, it may be desired to produce an ophthalmic lens <NUM> having the lens substrate <NUM> only on a concave surface <NUM> of the functional element <NUM>. Accordingly, a primer <NUM> may be applied to, as the treated surface of the functional element <NUM>, the concave surface <NUM> of the functional element <NUM>. As described in <FIG>, the functional element <NUM> may be arranged within a casting mold such that a convex surface <NUM> of the functional element <NUM> is in contact with a concave insert of the casting mold and a void exists between the treated surface of the functional element <NUM> and a convex casting insert of the casting mold. Following introduction and at least partial curing of a lens substrate precursor, as described in <FIG>, the treated surface of the functional element <NUM> and adhered lens substrate <NUM> may be removed from the casting mold. As desired, the ophthalmic lens <NUM> may include the lens substrate <NUM> on the concave surface <NUM> of the functional element <NUM>. The lens substrate <NUM> may be, in an example, a thermoset lens substrate such as CR39®.

In view of the flow diagrams of <FIG> and <FIG>, <FIG> provides an exemplary illustration of method <NUM>, wherein adherence between a functional element <NUM> and a lens substrate <NUM> is shown, the functional element <NUM> including a first thermoplastic film, a functional film, and a second thermoplastic film. In an embodiment, it may be desired to produce an ophthalmic lens <NUM> having the lens substrate <NUM> only on a convex surface <NUM> of the functional element <NUM>. Accordingly, a primer <NUM> may be applied to, as the treated surface of the functional element <NUM>, the convex surface <NUM> of the functional element <NUM>. As described in <FIG>, the functional element <NUM> may be arranged within a casting mold such that a concave surface <NUM> of the functional element <NUM> is contact with a convex casting insert of the casting mold and a void exists between the treated surface of the functional element <NUM> and a concave cavity insert of the casting mold. Following introduction and at least partial curing of a lens substrate precursor, as described in <FIG>, the treated surface of the functional element <NUM> and adhered lens substrate <NUM> and may be removed from the casting mold. As desired, the ophthalmic lens <NUM> may include the lens substrate <NUM> on the convex surface <NUM> of the functional element <NUM>. The lens substrate <NUM> may be, in an example, a thermoset lens substrate such as CR39®.

With reference now to <FIG>, a description of an exemplary embodiment of the present disclosure is provided, wherein a functional element including a first thermoplastic film, a functional film, and a second thermoplastic film is adhered to a lens substrate on two surfaces of the functional element.

At sub process <NUM> of method <NUM>, the convex surface and the concave surface of the functional element may be treated. Treatment may include application of a primer to the convex surface and the concave surface of the functional element. Sub process <NUM> of method <NUM> will be described in further detail with reference to <FIG>.

At sub process <NUM> of method <NUM>, the treated functional element may be adhered to a lens substrate in a similar manner to that of <FIG>. The adherence may include forming the lens substrate from a lens substrate precursor within a void of a casting mold, as shown in <FIG>.

With reference now to <FIG>, sub process <NUM> of method <NUM> describes treatment of the convex surface and the concave surface of the functional element.

At step <NUM> of sub process <NUM>, a primer may be applied to the convex surface and the concave surface of the functional element.

According to an embodiment, the primer may be one of a plurality of primers that provide robust adhesion between the surfaces of the functional element and the lens substrate. The primers may be formulated to include components that promote bonding to the functional element and the lens substrate. While conventional primers rely on relatively weak primer-primer and primer-substrate electrostatic forces for adhesion, the primers of the present disclosure may bind to the surfaces to which they are applied. The net result of the primers is enhanced adhesive strength and durability.

In an embodiment, a primer as disclosed herein may include at least one first reactive monomer, at least one second reactive monomer, and at least one photoactivatable catalyst. In an embodiment, the primer further includes a solvent. The at least one first reactive monomer may be a mixture of at least one acrylic monomer selected from the group consisting of monoacrylate monomers and diacrylate monomers and at least one acrylate monomer selected from the group consisting of triacrylate monomers through hexaacrylate monomers. In an example, a reactive group of the at least one second reactive monomer may be an epoxy. The at least one second reactive monomer may be an epoxy monomer selected from glycidylethers of polyhydric alkanols. The at least one photoactivatable catalyst may be a light-activated catalyst. In an example, the light activator may be electromagnetic radiation such as UV light, visible light, or infrared light, among others. According to the invention, the at least one photoactivable catalyst is a cationic catalyst and may be selected from the group consisting of aromatic onium salts and iron arene salt complexes. According to the invention, the primer further includes, as a component of the photoactivatable catalyst, a free radical photoinitiator. The free radical photoinitiator may be one selected from the group consisting of benzophenone and acetophenone.

In an example, the at least one first reactive monomer may be an at least one monomer that is capable of reacting with a lens substrate monomer. The at least one monomer may be included in an amount of between <NUM> wt. % and <NUM> wt. %, and preferably between <NUM> wt. % and <NUM> wt. % based on a total weight of the at least one second reactive monomer and the at least one monomer present in the composition. In an embodiment, the at least one monomer may be a mixture of acrylate monomers.

According to an embodiment, the at least one second reactive monomer may have a molecular weight of between about <NUM> and about <NUM>,<NUM>. The at least one second reactive monomer may be included in an amount of between <NUM> wt. % and <NUM> wt. %, and preferably between <NUM> wt. % and <NUM> wt. %, based on a total weight of the at least one second reactive monomer and the at least one first reactive monomer. In an embodiment, the at least one second reactive monomer may be a mixture of epoxy resin and cycloaliphatic epoxy. In an embodiment, the at least one reactive monomer may be an alkoxysilane such as allyltrimethoxysilane, allyltriethoxysilane, allylmethacrylate, and vinyltrimethoxysilane.

In some embodiments, a solvent may be used to dissolve the primer components. When present, the solvent may be included in an amount of between <NUM> wt. % and <NUM> wt. In an example, the solvent is an alcohol such as methanol, ethanol, n-propanol, and isopropanol, among others. In another example, the solvent may be a ketone, acetate solvent, acetone, methyl ethyl ketone, ethyl acetate, cyclopentanone and cyclohexanone, and any combination thereof.

According to an embodiment, the at least one first reactive monomer may be of the same chemical functionality as the lens substrate monomer. When the at least one first reactive monomer is of the same chemical functionality as the lens substrate monomer, the at least one first reactive monomer aids in ensuring compatibility of the primer composition with the polymerized lens substrate monomer, also referred to herein as the lens substrate precursor. In some embodiments, the at least one first reactive monomer has a different chemical functionality from the lens substrate monomer. The at least one first reactive monomer may have different chemical functionality from the lens substrate monomer, but may still be able to react with the lens substrate monomer. In this case, the at least one first reactive monomer is selected to include the same reactive functional group as the lens substrate monomer. For example, a lens substrate monomer may primarily consist of allyl diglycol carbonate (i.e. CR39®), and the at least one first reactive monomer may be diallyl ether. Although the lens substrate monomer and the at least one first reactive monomer are different compounds, they may react with each other by virtue of their reactive functional group. In some aspects, the at least one first reactive monomer comprises a reactive group functionality of <NUM> or more, and preferably at least <NUM>. Increasing the reactive functionality increases the types of functional groups with which the at least one first reactive monomer can react. The at least one first reactive monomer may include a reactive group or groups selected from the group consisting of allyl, vinyl, acrylic, thiol, isocyanate, epoxy and amine.

According to an embodiment, the primers may be applied to a PC-based functional element by flow coating, spin coating, gravure coating, slot die coating, or other means known to those of skill in the art. For instance, the primer may be applied by draw down board method with Mayer rods, wherein the Mayer rods were wire wound MR#<NUM>, the diameter of the wire determining how the thickness of primer applied. In some aspects, and when solvent is included within the primer, the applied primer may be dried for a predetermined time of, for example, between about <NUM> seconds and about <NUM> minutes at a predetermined temperature of between, for example, about <NUM> and about <NUM> in order to remove the solvent from the primer composition. Other drying conditions known to those of skill in the art may be employed to remove the solvent when the solvent is present in the primer. According to an embodiment, the applied primer may be allowed to fully or partially dry after application to the functional element.

Exemplary compositions of the primers are described above with reference to Table <NUM> and Table <NUM>.

The applied primer may be exposed to an amount of UV light and/or an increase in temperature sufficient to activate the photoactivatable catalyst and initiate the curing process. Accordingly, in an embodiment, at step <NUM> of sub process <NUM>, the primed surfaces of the functional element may be at least partially cured by exposure to electromagnetic radiation. The electromagnetic radiation may be UV light, infrared light, or visible light, among others. In an example, the electromagnetic radiation is UV light provided by a Heraeus oblelight F300S with a H+ bulb. Power, energy, and exposure time may be selected to optimize curing. Typical, non-limiting curing conditions include about <NUM> feet/min (UVA ~1500mJ/cm<NUM>, ~1200mW/cm<NUM>) to about <NUM> feet/min (500mJ/cm<NUM>, 1100mW/cm<NUM>).

At step <NUM> of sub process <NUM>, the UV-cured primer on the concave surface and the convex surface of the functional element may be further cured by exposure to heat. In an example, the heat may be applied by an infrared oven. The infrared oven may be heated to <NUM>°F, for instance, and the UV-cured primer on the concave surface and the convex surface of the functional element may be exposed to the heat for a predetermined time. For instance, the predetermined time may be between <NUM> seconds and <NUM> seconds, and preferably about <NUM> seconds. Of course, it can be appreciated that the temperature and predetermined time for heating the UV-cured primer on the concave surface and the convex surface of the functional element may be based on a desired hardness. In certain applications, a less than <NUM>% cured primer may be desired in order to promote adhesion.

In view of the flow diagrams of <FIG> and <FIG>, <FIG> provides an exemplary illustration of method <NUM>, wherein adherence between a functional element <NUM> and a lens substrate <NUM> is shown, the functional element <NUM> including a first thermoplastic film, a functional film, and a second thermoplastic film. In an embodiment, it may be desired to produce an ophthalmic lens <NUM> having the lens substrate <NUM> on both of a concave surface <NUM> of the functional element <NUM> and a convex surface <NUM> of the functional element <NUM>. Accordingly, a primer <NUM> may be applied to, as the treated surfaces of the functional element <NUM>, the concave surface <NUM> of the functional element <NUM> and the convex surface <NUM> of the functional element <NUM>.

As described in <FIG>, the functional element <NUM> may be arranged within a casting mold such that a first predetermined distance remains between the convex surface <NUM> of the functional element <NUM> and a concave cavity insert of the casting mold and a second predetermined distance remains between the concave surface <NUM> of the functional element <NUM> and a convex cavity insert of the casting mold. In this way, voids of the casting mold may exist within space defined by the first predetermined distance and the second predetermined distance, treated surfaces of the functional element <NUM> being exposed thereto. Following introduction and at least partial curing of a lens substrate precursor within the voids, as described in <FIG>, the treated surfaces of the functional element <NUM> that are adhered to the lens substrate <NUM> may be removed from the casting mold. As desired, the ophthalmic lens <NUM> may include, as the lens substrates, a convex lens substrate <NUM> on the convex surface <NUM> of the functional element <NUM> and a concave lens substrate <NUM> on the concave surface <NUM> of the functional element <NUM>. The convex lens substrate <NUM> and the concave lens substrate <NUM> may be, in an example, thermoset lens substrates such as CR39®.

As part of the present disclosure, specific examples are included below. The examples are for illustrative purposes only and are not intended to limit the invention. In fact, the examples may not be exemplary embodiments of the present disclosure but instead examples intended to provide contrast between non-limiting examples of the present disclosure and other practices in the field. Those of ordinary skill in the art will readily recognize parameters that can be changed or modified to yield essentially the same results.

For each of the subsequent Example, a base primer composition is first described.

A reference base primer composition, defined as Base Composition #<NUM>, was formulated and composed of, as the at least one first reactive monomer, acrylate monomer and acrylate, as the at least one second reactive monomer, epoxy resins and acrylate monomers, and, as the at least one photoinitiator, a cationic photoinitiator and free radical photoinitiator, as shown in Table <NUM>.

In an example, UVR-<NUM> is a <NUM>,<NUM>-epoxy cyclohexyl methyl-<NUM>,<NUM>-epoxycyclohexylcarboxylate having a reactive group functionality of <NUM>, Erisys GE-<NUM> is a trimethylolpropane triglycidyl ether liquid epoxy having a reactive group functionality of <NUM>, SR-<NUM> is a dipentaerythritol pentaacrylate ester having a reactive group functionality of <NUM>, SR-<NUM> is a <NUM>-phenoxyethyl acrylate having a reactive group functionality of <NUM>, UVI-<NUM> is a mixed triarylsulfonium hexafluoroantimonate <<NUM>% in propylene carbonate, and Darocur <NUM> is <NUM>-Hydroxy-<NUM>-methyl-<NUM>-phenyl-propan-<NUM>-one.

Primer <NUM> of Example <NUM> included REFERENCE BASE COMPOSITION #<NUM> (<NUM> wt. %) and allyl methacrylate (<NUM> wt. Primer <NUM> was applied to both surfaces of a flat functional element which was then thermoformed to a desired curvature in order to generate an ophthalmic lens having a concave lens substrate and a convex lens substrate adhered to the functional element. Accordingly, Primer <NUM> was first applied to a first flat surface of the functional element, and UV-cured to tack free, as in <FIG>. The functional element having the treated first flat surface was then primed on the second flat surface of the functional element and cured, as described above. The primer was applied to each of the first flat surface of the functional element and the second flat surface of the functional element by draw down board method using a #<NUM> Mayer rod. Discs of the functional element were die cut and thermoformed to a <NUM>-base curvature prior to positioning within a semi-finished lens casting cell, as described above. One or more voids remained on either side of the functional element. The casting mold was then filled with, as a lens substrate precursor, a thermoset CR39® monomer containing about <NUM>% isopropylperoxydicarbonate (IPP). The filled casting mold was cured to a desired hardness and the SF lens was surface to either of a -<NUM> diopter or a -<NUM> diopter.

Primer <NUM> of Example <NUM> included REFERENCE BASE COMPOSITION #<NUM> (<NUM> wt. %) and allyl trimethoxysilane (<NUM> wt. Primer <NUM> was applied to both surfaces of a flat functional element which was then thermoformed to a desired curvature in order to generate an ophthalmic lens having a concave lens substrate and a convex lens substrate adhered to the functional element. Accordingly, Primer <NUM> was first applied to a first flat surface of the functional element, and UV-cured to tack free, as in <FIG>. The functional element having the treated first flat surface was then primed on the second flat surface of the functional element and cured, as described above. The primer was applied to each of the first flat surface of the functional element and the second flat surface of the functional element by draw down board method using a #<NUM> Mayer rod. Discs of the functional element were die cut and thermoformed to a <NUM>-base curvature prior to positioning within a semi-finished lens casting cell, as described above. One or more voids remained on either side of the functional element. The casting mold was then filled with, as a lens substrate precursor, a thermoset CR39® monomer containing about <NUM>% IPP. The filled casting mold was cured to a desired hardness and the SF lens was surface to either of a -<NUM> diopter or a -<NUM> diopter.

Primer <NUM> of Example <NUM> included REFERENCE BASE COMPOSITION #<NUM> (<NUM> wt. %) and allyl triethoxysilane (<NUM> wt. Primer <NUM> was applied to both surfaces of a flat functional element which was then thermoformed to a desired curvature in order to generate an ophthalmic lens having a concave lens substrate and a convex lens substrate adhered to the functional element. Accordingly, Primer <NUM> was first applied to a first flat surface of the functional element, and UV-cured to tack free, as in <FIG>. The functional element having the treated first flat surface was then primed on the second flat surface of the functional element and cured, as described above. The primer was applied to each of the first flat surface of the functional element and the second flat surface of the functional element by draw down board method using a #<NUM> Mayer rod. Discs of the functional element were die cut and thermoformed to a <NUM>-base curvature prior to positioning within a semi-finished lens casting cell, as described above. One or more voids remained on either side of the functional element. The casting mold was then filled with, as a lens substrate precursor, a thermoset CR39® monomer containing about <NUM>% IPP. The filled casting mold was cured to a desired hardness and the SF lens was surface to either of a -<NUM> diopter or a -<NUM> diopter.

Primer <NUM> of Example <NUM> included REFERENCE BASE COMPOSITION #<NUM> (<NUM> wt. %) and vinyl trimethoxysilane (<NUM> wt. Primer <NUM> was applied to both surfaces of a flat functional element which was then thermoformed to a desired curvature in order to generate an ophthalmic lens having a concave lens substrate and a convex lens substrate adhered to the functional element. Accordingly, Primer <NUM> was first applied to a first flat surface of the functional element, and UV-cured to tack free, as in <FIG>. The functional element having the treated first flat surface was then primed on the second flat surface of the functional element and cured, as described above. The primer was applied to each of the first flat surface of the functional element and the second flat surface of the functional element by draw down board method using a #<NUM> Mayer rod. Discs of the functional element were die cut and thermoformed to a <NUM>-base curvature prior to positioning within a semi-finished lens casting cell, as described above. One or more voids remained on either side of the functional element. The casting mold was then filled with, as a lens substrate precursor, a thermoset CR39® monomer containing about <NUM>% IPP. The filled casting mold was cured to a desired hardness and the SF lens was surface to either of a -<NUM> diopter or a -<NUM> diopter.

Following removal from the casting molds and surfacing, minimal to no haze and minimal demolding or delamination were observed in semi-finished lenses containing internally-positioned functional elements that were treated with any of Examples <NUM>-<NUM>. Results of these lenses are shown in Table <NUM>.

Obviously, numerous modifications and variations are possible in light of the above teachings. 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.

Claim 1:
An ophthalmic lens, comprising:
at least one polymerized lens substrate (<NUM>,<NUM>) including at least one thermoset monomer;
a functional component (<NUM>,<NUM>,<NUM>,<NUM>) including at least one thermoplastic film, (<NUM>) a surface of the at least one thermoplastic film facing the polymerized lens substrate; and
a primer coating (<NUM>,<NUM>,<NUM>) deposited onto the surface of the at least one thermoplastic film facing the polymerized lens substrate,
wherein
the primer coating includes
at least one first reactive monomer,
at least one second reactive monomer, and
at least one photoactive catalyst;
characterized in that
the at least one second reactive monomer of the primer coating being an alkoxysilane and in that
the at least one photoactive catalyst includes a cationic photoinitiator and a free radical photoinitiator.