Functionalized optical layered structures, functionalized optical articles, eyewear incorporating functionalized optical articles, and methods of making same

Abstract

A functionalized optical layered structure, a functionalized optical article, an eyewear including the functionalized optical article, and methods of making the same. A functionalized optical layered structure comprises:-a first element representing a first single-layer or multi-layer functional film (15); -at least one second element selected from the group consisting of a protective liner layer, or a base optical element (1), or a second functional film-at least one pressure-sensitive adhesive layer placed in contact with at least one surface of said first element and at least one surface of said second element, the at least one pressure sensitive adhesive layer (14 ') has optical quality and includes a colorant (12).

Description

Technical Field

[0001] The present invention relates to a functionalized optical layered structure, a functionalized optical article, an eyewear comprising the functionalized optical article, and a method for making the same. Background Art

[0002] The process of making functionalized optical layered structures, such as ophthalmic tinted lenses, includes several manufacturing methods.

[0003] As is known in the art, lenses are usually tinted by introducing color additives into the molten glass, and similarly, polycarbonate lenses are injection molded from pre-colored plastic pellets. A disadvantage associated with these methods is that flexibility is very limited in the range of colors that can be provided. In addition, lenses with widely varying thicknesses also exhibit non-uniform transmittance when tinted by this method.

[0004] Conventionally, a dip dyeing method has been used as one of the dyeing methods for dyeing plastic lenses of spectacles in most cases. This dip dyeing method includes: preparing a dyeing solution by mixing disperse dyes of three primary colors of red, blue and yellow and dispersing the mixture in water; heating the dyeing solution to about 90° C.; and dipping a plastic lens in the heated solution, thereby dyeing the lens.

[0005] As an alternative to the immersion dyeing method, a vapor deposition or sublimation dyeing method has been proposed, for example, as disclosed in document JP-A-01 277 814. This method involves heating a sublimable solid dye under vacuum to sublime the solid dye and vapor-depositing the sublimated dye onto a plastic lens while heating the plastic lens under vacuum, thereby dyeing the lens.

[0006] More precisely, if Figure 1a to Figure 1c As disclosed, the sublimation method comprises a sublimation step ( Figure 1a ), during which the optical substrate element 1 is placed in a sublimation enclosure 2, wherein the sublimable colorant 3 pre-printed on the surface of the paper support 4 and facing the optical substrate element 1 is sublimated and then deposited on the facing surface 6 of the optical substrate element 1, which produces Figure 1b An assembly is shown in which the upper surface 6 of the optical substrate element 1 is covered with a sublimated colorant 3 .

[0007] exist Figure 1cAnother step occurring in the depicted imbibition enclosure includes fixing the colorant on the surface of the optical substrate element by exposing the assembly 1, 3 to heat for a sufficient period of time to allow the colorant to be fixed to the surface and / or thickness of the substrate element. This method is particularly popular because it produces little colorant waste compared to less sustainable methods such as the above-mentioned immersion coloring method, does not require using more colorant than is necessary, and only requires printing the colorant on paper and then allowing it to sublime and fix to the lens.

[0008] However, depending on the chemical nature of the optical substrate element 1, the imbibition step may take more than an hour or even several hours to effectively fix the coloring agent on / penetrate the lens. In addition, due to the relatively long imbibition time and temperature, some already functionalized optical substrate elements cannot withstand this coloring method and need to be colored using alternative solutions such as immersion coloring processes, which are known to have poor sustainability. In addition, for curved optical substrate elements, such as Figure 1c As depicted, the colorant is usually deposited on the concave surface rather than on its convex surface, so as to avoid any migration of the sublimated colorant towards the periphery of the optical substrate element, which would occur if the colorant were deposited on the convex side. Moreover, during the imbibition step, the obtained colored optical substrate element is then turned over so that its colored concave side faces the bottom of the imbibition box, now avoiding any migration of the colorant to the center of the lens during the imbibition step, thus avoiding the creation of unwanted color gradients ( Figure 1c ). Due to this configuration, it is often observed that some wasted toner is deposited on the bottom base of the imbibition enclosure rather than being fixed to the concave surface of the optical base element. This means that for a given target lens color, a slightly larger amount of toner will need to be printed in anticipation of the toner waste 3' that occurs during the imbibition step.

[0009] Therefore, both the immersion dyeing method and the conventional sublimation dyeing method have the disadvantage of not being able to provide a lens with stable dyeing. In particular, it is difficult to dye a lens with low dyeability, or it is difficult to dye a lens into a dark color or a color with a high density. In the case of both the sublimation method and the immersion dyeing method, the possibility of dyeing an already functionalized lens is even more minimal.

[0010] On the other hand, the optical article may be provided with additional functionalized structures consisting of single-layer or multi-layer structures, which may be laminated on and adhered to the optical substrate element to provide specific functionality to the obtained article, such as scratch resistance, polarization ...

[0011] However, in this case, if the optical article must be tinted, it is the optical base element that needs to be tinted, which avoids later color shade differences, or it is one of the functional layers of the additional functionalized structure that needs to be tinted, which requires the above-mentioned relatively time-consuming coloring method and / or the use of relatively large amounts of dye to achieve the target color shade for the darkest optical article to be obtained.

[0012] Therefore, there is a substantial need for new, industrially efficient methods for tinting optical lenses which will not suffer from the disadvantages of prior art systems. Summary of the invention

[0013] According to the present disclosure, this object is achieved by a functionalized optical layered structure comprising:

[0014] - a first element, which represents a first single-layer or multi-layer functional film;

[0015] - at least one second element selected from a protective backing layer, a base optical element, or a second functional film

[0016] - at least one pressure-sensitive adhesive layer placed in contact with at least one surface of said first element and at least one surface of said second element, having optical quality and comprising a coloring agent.

[0017] The fact that the pressure sensitive adhesive layer is a material comprising a colorant has the benefit that the time required for the colorant to be fixed and the amount of colorant required to achieve a specific hue are reduced compared to the time and amount of dye required when the colorant is sublimated on a plastic lens and even compared to methods where the base element or functional layer of the multilayer structure needs to be dyed. Another benefit is the possible late differentiation and the possibility of defining a one-piece flow process due to the speed of the method.

[0018] Advantageously, the colorant comprises a sublimable, printable, sprayable or inkjettable colorant.

[0019] Preferably, the second element is a base optical element and the at least one pressure sensitive adhesive layer defines a peel force when dry and a peel force when wet, each higher than 13 N / 25 mm, to separate the first element from the second element.

[0020] More preferably, the decrease between the peel force of the pressure sensitive adhesive layer (14') when dry and the peel force when wet is no greater than at least 35%.

[0021] According to an advantageous embodiment, the storage modulus G' of the pressure-sensitive adhesive layer at 85°C is lower than 1.6×10 5 Pa, preferably less than or equal to 1.5×10 5Pa, and the dry peel strength and wet peel strength exhibited by the pressure-sensitive adhesive layer are both higher than 20N / 25mm, preferably both in the range of 21N / 25mm to 40N / 25mm, including end values.

[0022] According to yet other aspects of the present invention, the functionalized optical layered structure may include any of the following features considered individually or in combination with each other and / or the above features:

[0023] - these colorants include sublimable, printable, sprayable or inkjet colorants,

[0024] - the at least one pressure-sensitive adhesive layer has a thickness ranging from 5 μm to 150 μm or more,

[0025] - the pressure-sensitive adhesive material is selected from compounds based on polyacrylates,

[0026] -The first element represents a functional film, which includes at least one function selected from the following items: color, polarization, photochromic, electrochromic, impact resistance, wear resistance, anti-static, anti-glare, anti-fouling, anti-fog, rain protection, interference coating (such as anti-reflective coating or mirror coating), dichroic filter, and spectral filter on a specified wavelength band.

[0027] The present invention relates to a functionalized optical product, comprising a substrate element and a functionalized optical layered structure applied on one surface of the substrate element, wherein the functionalized optical layered structure comprises:

[0028] - a first element, which represents a first single-layer or multi-layer functional film;

[0029] - at least one second element selected from a protective backing layer, a base optical element, or a second functional film

[0030] - at least one pressure-sensitive adhesive layer placed in contact with at least one surface of the first element and at least one surface of the second element, wherein the at least one pressure-sensitive adhesive layer is of optical quality and comprises a coloring agent.

[0031] Advantageously, the functionalized optical layered structure of the functionalized optical article may include any combination of the features of the functionalized optical layered structure described above.

[0032] According to another aspect, the present invention relates to an eyewear device comprising a support structure, such as a frame, and at least one functionalized optical article intended to be enclosed in the support structure and to be edged according to the dimensions of the support structure, the functionalized optical article comprising a substrate element and a functionalized optical layered structure applied to the substrate element, the functionalized optical layered structure comprising:

[0033] - a first element, which represents a first single-layer or multi-layer functional film;

[0034] - at least one second element selected from a protective backing layer, a base optical element, or a second functional film

[0035] at least one pressure-sensitive adhesive layer placed in contact with at least one surface of said first element and at least one surface of said second element,

[0036] The at least one pressure sensitive adhesive layer is of optical quality and includes a colorant.

[0037] According to an embodiment of the eyewear device, the different layers of the base element of the edged functionalized optical article adhere to each other or without any bubbles or peeling between consecutive layers through the entire edged surface and up to the edge of the optical article.

[0038] Preferably, the functionalized optical layered structure of the eyewear device may include any combination of the features of the functionalized optical layered structure described above.

[0039] The present invention also relates to a method for manufacturing a functionalized optical layered structure, the method comprising the following steps:

[0040] -Providing a functionalized optical layered structure, the functionalized optical layered structure comprising:

[0041] A first element, which represents a first single-layer or multi-layer functional film

[0042] at least one pressure sensitive adhesive layer, wherein the at least one pressure sensitive adhesive layer has optical quality

[0043] - Coloring at least one surface of at least one pressure-sensitive adhesive layer with a coloring agent.

[0044] Ideally, the step of coloring the at least one pressure-sensitive adhesive layer is a sublimation step, the colorant is sublimable, and during the sublimation step, the at least one pressure-sensitive adhesive layer is in a flat form, and the colorant transfer support facing the at least one pressure-sensitive adhesive layer is in a flat form. Optionally, if the consumable incorporating the at least one pressure-sensitive adhesive layer is in a preformed or curved configuration, the at least one pressure-sensitive adhesive layer may not be flat (i.e., curved).

[0045] In this case, the distance between the toner transfer support and the at least one pressure-sensitive adhesive layer is lower than 15 mm, preferably lower than 12 mm and preferably higher than 5 mm.

[0046] According to an embodiment of interest, the method further comprises an imbibing step to fix said coloring agent to at least one pressure-sensitive adhesive layer after the coloring step.

[0047] In this case, advantageously, during the imbibing step, the at least one pressure-sensitive adhesive layer is arranged such that the surface of the at least one pressure-sensitive adhesive layer on which the toner is deposited constitutes the upper surface of the at least one pressure-sensitive adhesive layer.

[0048] More preferably, the imbibition step comprises heating at least one pressure-sensitive adhesive layer at a temperature and for a time that allows softening without melting the at least one pressure-sensitive adhesive layer, for example, for less than 1 hour and less than 90°C, preferably for 10 minutes and less than 90°C, so that the colorant is fixed on the surface of the at least one pressure-sensitive adhesive layer and / or penetrates the thickness of the at least one pressure-sensitive adhesive layer.

[0049] Advantageously, the heating step comprises heating at least one pressure-sensitive adhesive layer by air convection or by irradiation of the surface, for example with IR / UV lasers.

[0050] The method of manufacturing a functionalized optical layered structure may include any of the following features considered individually or in combination with each other and / or the above features:

[0051] - before the step of placing at least one pressure-sensitive adhesive in contact with said at least one surface of said second element, a step of coloring said at least one pressure-sensitive adhesive layer with a coloring agent is carried out,

[0052] the colorant is a sublimable, printable, sprayable or inkjettable colorant, and wherein the step of coloring the at least one pressure-sensitive adhesive layer is a step of sublimating, printing, spraying or inkjetting the colorant onto the at least one pressure-sensitive adhesive layer,

[0053] - Subjecting the surfaces of the first and second elements intended to be placed in contact with the at least one adhesive layer to a surface treatment selected from the following before the contact placement: plasma treatment in an inert nitrogen atmosphere at a dose ranging from 40 W·min / m2 to 100 W·min / m2 and corona treatment in ambient air at a dose ranging from 40 W·min / m2 to 50 W·min / m2, so that the reduction between the peel force under dry conditions and the peel force under wet conditions is less than or equal to 35% (including the end values).

[0054] According to a possible embodiment, the PSA supported between two protective liner layers can also be colored.After the PSA has been colored, it can be applied to a first element in the form of a functional film and then to a second element in the form of an optical substrate element.

[0055] The present invention also relates to a method for manufacturing a functionalized optical article, the method comprising:

[0056] - a step of thermoforming the functionalized optical layered structure according to the substrate element curvature of the substrate element, the functionalized optical layered structure comprising:

[0057] ○ A first element, the first element representing a first single-layer or multi-layer functional film;

[0058] ○ At least one second element, the at least one second element is selected from a protective liner layer or a second functional film

[0059] o at least one pressure sensitive adhesive layer placed in contact with at least one surface of the first element and at least one surface of the second element, wherein the at least one pressure sensitive adhesive layer is of optical quality and includes a coloring agent

[0060] - A step of fixing the thermoformed ophthalmic functional film structure on the substrate element.

[0061] Preferably, the functionalized optical layered structure of the above manufacturing method may include any combination of the features of the above functionalized optical layered structure.

[0062] According to another aspect, the present invention is directed to a method of manufacturing an eyewear device, the method comprising:

[0063] - a step of thermoforming an ophthalmic functional membrane structure according to the curvature of the substrate element, the ophthalmic functional membrane structure comprising:

[0064] ○ A first element, the first element representing a first single-layer or multi-layer functional film;

[0065] o at least one second element, the at least one second element is selected from a protective backing layer or a second functional film;

[0066] o at least one pressure sensitive adhesive layer placed in contact with at least one surface of the first element and at least one surface of the second element, wherein the at least one pressure sensitive adhesive layer is of optical quality and includes a colorant;

[0067] - a step of fixing the thermoformed ophthalmic functional film structure on the substrate element; and

[0068] - A step of edge grinding of the thermoformed ophthalmic functional film structure applied to the substrate element according to the dimensions of the support structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] For a more complete understanding of the description provided herein and the advantages thereof, reference is now made to the following brief description taken in conjunction with the accompanying drawings and detailed description, wherein like reference numerals represent like parts.

[0070] - Already mentioned Figure 1a to Figure 1c The following are the steps for producing a functionalized optical layered structure according to the prior art.

[0071] - Figure 2a 2g represent the successive steps of manufacturing a functionalized optical layered structure according to the present invention, FIG. 2g shows two embodiments of functionalized optical articles obtained when the functionalized optical layered structure is arranged on the concave side ( FIG. 2g. α) and the convex side ( FIG. 2g. β) of an optical substrate element,

[0072] - Figure 3 Schematically represents a functionalized optical layered structure according to the present invention,

[0073] - Figure 4 Shown are diagrams with histograms representing the peel force of different PSA layers (with or without colorant) for different wicking times under wet conditions (black symbols) and dry conditions (white symbols). DETAILED DESCRIPTION

[0074] In the following description, the drawings are not necessarily drawn to scale and for the purpose of clarity and simplicity or for information purposes, certain features may be shown in a generalized or schematic form. In addition, although the manufacture and use of various embodiments are discussed in detail below, it should be understood that many inventive concepts that can be implemented in a variety of contexts are provided herein. The embodiments discussed herein are merely representative and do not limit the scope of the invention. It is also apparent to those skilled in the art that all technical features defined relative to the method can be transposed to the device individually or in combination, and conversely, all technical features relative to the device can be transposed to the method individually or in combination.

[0075] To avoid detail not necessary to practice the invention, the description may omit certain information known to those skilled in the art.

[0076] Detailed Description

[0077] While representative methods and apparatus have been described in detail herein, those skilled in the art will recognize that various substitutions and modifications may be made without departing from the scope described and defined by the appended claims.

[0078] Optical products / optical (substrate) elements

[0079] According to the present invention, the optical article comprises at least one pressure-sensitive adhesive layer having optical quality and comprising a colorant, and the at least one pressure-sensitive adhesive layer is placed in contact with at least one surface of a first element and at least one surface of a second element.

[0080] The fact that the pressure sensitive adhesive layer is a material comprising a colorant has the following advantages: compared to when the colorant is sublimated on a plastic lens (e.g. Figure 1a to Figure 1c The time required for the colorant to be fixed and the amount of colorant required to achieve a specific hue are reduced compared to the time required for the conventional method shown (as in the case of the conventional method).

[0081] More precisely, for the purposes of the present invention, an optical article is considered transparent when viewing an image through this element is perceived without significant contrast loss. Unless otherwise specified, a transparent optical element intervenes between the image and the image observer without significantly reducing the image quality. In the field of ophthalmology, this definition is considered to be met when the optical element has a haze of not more than 1, preferably not more than 0.4. Within the meaning of the present invention, this definition of the term "transparent" applies to all objects so considered in this specification.

[0082] Optical articles are defined herein as one of ophthalmic elements / lenses, eye shields, and vision optical systems. Non-limiting examples of ophthalmic elements include corrective and non-corrective lenses, including single vision lenses or multifocal lenses, which may be segmented or non-segmented, and other elements used to correct, protect, or enhance vision, including but not limited to magnifying lenses and protective lenses or goggles, such as found in spectacles, glasses, sunglasses, goggles, and helmets.

[0083] The optical article is composed of an optical substrate element coated with a functional structure, both of which are described below.

[0084] The optical substrate element may be a standard component selected from the group consisting of an optical lens, a window, a goggle, preferably an optical lens, more preferably an ophthalmic lens.

[0085] The optical substrate element may be selected from the group consisting of a finished lens, a semi-finished lens, a progressive addition lens, an afocal lens, a plano lens, a single vision lens, and a multifocal lens.

[0086] A semi-finished lens (SF) is a lens that has one optical surface and another surface that needs to be ground according to the wearer's prescription.

[0087] The optical substrate element can be made of any material classically used in optical devices. In particular, the optical substrate element is made of plastic, which can be a thermoplastic or a thermosetting material. Examples of plastics include polycarbonate; polyamide; polyimide; polysulfone; copolymers of polyethylene terephthalate and polycarbonate; polyolefins, i.e., polynorbornene; polymers and copolymers of diethylene glycol bis(allyl carbonate); (meth)acrylic polymers and copolymers, i.e., (meth)acrylic polymers and copolymers derived from bisphenol-A; thio(meth)acrylic polymers and copolymers; urethane and thiourethane polymers and copolymers; epoxy polymers and copolymers; and episulfide polymers and copolymers. In a preferred embodiment, the optical substrate element is made of polycarbonate or a high refractive poly(thio)urethane with an optical refractive index between 1.60 and 1.67 or an episulfide with an optical refractive index between 1.60 and 1.67. More preferably, the optical base element is made of a (thio)urethane-based prepolymer or an episulfide monomer.

[0088] Functional membrane structure

[0089] Functional membrane structures consist of the following:

[0090] - a single-layer or multi-layer structure supported by an optional supporting film or carrier,

[0091] - at least one pressure-sensitive adhesive layer (PSA layer) of optical quality to permanently hold the functional film structure on the surface of the optical substrate element,

[0092] - Peelable protective liner layers, one of which is in direct contact with the surface of the PSA layer, and a second of which is in direct contact with the monolayer, multilayer structure or support film of the functional film structure.

[0093] Preferably, the support film is made of cellulose triacetate (TAC) and has a thickness of at least 40 microns, preferably has a thickness in the range of 40 μm to 300 μm, and preferably has a thickness of 80 μm to 190 μm. The material of the support film can be selected from the group of films made of: cellulose triacetate (TAC), cellulose acetate butyrate (CAB), polycarbonate (PC), poly (ethylene terephthalate) (PET), poly (methyl methacrylate) (PMMA), urethane polymer (TPU), cyclic olefin copolymer (COC), polyester block copolyamide (like Pebax) and polyimide.

[0094] The functional film structure that can be used in the present invention includes at least one functional film or a single-layer structure. In other words, the functional film structure can include one or more functional films, and the functional film structure can include different functions.

[0095] Various types of functional films can be used. Examples of functional films include tinted films, polarizing films, photochromic films, hard coating films, top coating films, antifogging films, antifouling films, antireflective films, and antistatic films. The functional film can have a single layer or multilayer structure. In other words, it refers to a single functional film or a layered structure, which includes at least one supporting film and one or more separate functional layers (coatings or films) adhered together with the same or different properties. Therefore, according to one embodiment, the functional film can include a supporting film, which is suitable for being adhered or fixed to an optical substrate element by an adhesive layer.

[0096] The different functional films, if any, can be bonded to each other due to surface treatment and / or adhesives, the preferred option of adhesives in the field of optics and ophthalmology being of the pressure-sensitive adhesive variety.

[0097] However, when the functional film structure comprises a multilayer structure having several PSA layers, the PSA layer to be colored according to the present invention is preferably composed of the PSA layer that is in direct contact with one of the two peelable liner layers, because it is easier to access after simply removing the protective liner layer than the other PSA layer. However, according to the present invention, the other PSA layer can also be colored.

[0098] Furthermore, when the functional film structure contains a single layer structure, the PSA layer surface to be colored according to the present invention is constituted by the PSA layer surface directly contacting one of the two releasable liner layers because it is more easily accessible after removing the protective liner layer.

[0099] Preferred embodiments of the functional membrane structure that can be used in the present invention may include those disclosed in patent application US2016 / 0216425 from the applicant and incorporated herein or those disclosed in patent application WO 2020 / 002606 also from the applicant and also incorporated herein by reference and in Figure 3 The embodiments shown above.

[0100] PSA "Pressure Sensitive Adhesive"

[0101] "Pressure sensitive adhesive" refers to a dry contact adhesive having viscoelastic properties which requires only very slight pressure to adhere to the surfaces between which it is placed.

[0102] "Pressure-sensitive adhesive layer" refers to a layer made of a pressure-sensitive adhesive, or refers to a layer made of a pressure-sensitive adhesive. Pressure-sensitive adhesives are characterized by their ability to exert a strong adhesive holding force on a surface without activation by water, solvents or heat.

[0103] The pressure-sensitive adhesive can be obtained in the form of a continuous layer made of a pressure-sensitive adhesive composition (i.e., a pressure-sensitive adhesive layer) on a removable liner layer (i.e., a release liner layer), or sandwiched between two removable liner layers (referred to as a pressure-sensitive adhesive film, PSA film, pressure-sensitive adhesive tape, or adhesive transfer tape).

[0104] EP 3436210, incorporated herein, describes a PSA particularly suitable for optical substrate elements according to the present invention to exhibit edge-optimizing properties. The pressure-sensitive adhesive constituting the pressure-sensitive layer useful in the present invention should have a storage modulus G' at 85°C of less than 1.6 x 10 5 Pa, preferably equal to or lower than 1.5 Pa, more preferably between 1.0 Pa and 1.5×10 5 85 degrees Celsius corresponds to the maximum temperature that can be applied to the optical element during a general edging step. In particular, this corresponds to the maximum theoretical value of the temperature generated by the friction of the edging wheel with the lens material when using aggressive conditions during the edging step.

[0105] Sunglasses according to Tv, color (a*, b*) category

[0106] Light transmittance (Tv) is the transmittance of an optical product perceived by an observer under a specified solar radiation (%). Light transmittance is preferably considered as the amount of light provided to the user by the optical article / product. Light transmittance is defined by the average transmittance value of the lens in the visible range 380 to 780 nm, which is weighted by the solar irradiance (D65) and the photopic visibility function (Vλ). The principle is to measure the spectral transmittance of the optical product at normal incidence at a reference point using a spectrometer.

[0107] In this way, the functionalized film structure according to the invention can be tailored to define different tints for sunglasses with different average visible light transmission factors Tv, together with the associated substrate or optical base element:

[0108] - above 80% (known as clear lenses of category 0 or class 0),

[0109] - from 43% to 80% (called category 1 or class of sunglasses),

[0110] - from 18% to 43% (known as Category 2 sunglasses),

[0111] - from 8% to 18% (called Category 3 sunglasses),

[0112] - Less than 8% (known as Category 4 sunglasses).

[0113] The optical product may include a photochromic lens, an electrochromic lens, a transparent lens, a blue light cut-off lens or a sun lens.

[0114] PSA coloring according to the invention

[0115] refer to Figure 2a As shown in FIG. 2g , in order to dye the PSA layer of the functional film structure, the inventors proposed a dyeing method, which is implemented in the following manner:

[0116] - A step of providing a functionalized optical layered structure 13, the functionalized optical layered structure comprising:

[0117] - A first element, which represents a first single-layer or multi-layer functional film 15

[0118] at least one pressure-sensitive adhesive layer 14 comprising at least one surface protected by a protective liner layer 17, the at least one pressure-sensitive adhesive layer being of optical quality, and

[0119] - A step of coloring at least one pressure-sensitive adhesive layer with a coloring agent.

[0120] Once the protective liner layer 17 is removed from the surface of the PSA layer, the step of coloring at least one pressure sensitive adhesive layer with a colorant can be accomplished by several known methods such as sublimation, inkjet printing of the colorant, spraying and / or screen printing of the colorant, preferably sublimation.

[0121] More preferably, if Figure 2b As shown, the step of coloring at least one pressure-sensitive adhesive layer is a sublimation step, wherein the coloring agent 12 is sublimable.

[0122] Prior to the sublimation step, the toner printing step includes applying (outputting) a dye ink containing a sublimable dye 12 to a toner transfer support or substrate 11 (such as paper) by using an inkjet printer.

[0123] As sublimable dyes (which contain dissolved or finely dispersed sublimable dyes), red, blue and yellow three disperse dye inks are used, and each ink is a commercially available water-based ink. These inks are filled in commercially available ink cartridges for inkjet printers, respectively. The ink cartridge is installed in the inkjet printer. This printer in the present embodiment is a commercially available printer.

[0124] Such a printing press can be controlled so that the adjustment of the tonal characteristics (hue, chroma, etc.) is handled by drawing software, CCM (computer color matching), etc. Accordingly, data on the desired color can be stored in the computer so that a matrix with the same color quality can be repeatedly produced as required. The color tone (e.g., gradient pattern) is also controlled in digital form, which makes it possible to reproduce the matrix repeatedly with the same color density as required.

[0125] Furthermore, before introducing the structure into a sublimation chamber (e.g. Figure 2b Before the functional film structure 13 is formed, the peelable liner layer 17 is removed from the surface of the adjacent PSA layer 14, thereby defining a PSA exposed surface structure 16 consisting of the PSA layer 14, the single-layer or multi-layer structure 15, the second peelable liner layer and / or the supporting film (if any) 20.

[0126] like Figure 2b As disclosed, during the sublimation step, the PSA exposed surface structure 16 is in a flat form, and the substrate 11 is also in a flat form and is preferably arranged above the PSA exposed surface structure 16, on which the toner 12 is pre-printed, the surface of the substrate printed with the toner facing the PSA exposed surface structure 16. The facing surfaces of the substrate 11 and the PSA exposed surface structure 16 are separated by a distance lower than 15 mm, preferably lower than 12 mm and preferably higher than 5 mm. A specific support device 18, for example in the form of a cylindrical interlocking sleeve, is provided to maintain both the substrate 11 and the PSA exposed surface structure 16 in a flat form, parallel to each other and separated from each other by a specific distance.

[0127] Due to the heat provided by the sublimation lamps 19 (these sublimation lamps are located above the substrate 11 printed with the toner or dye 12 facing the PSA bare surface structure 16 below) and due to the vacuum provided in the sublimation enclosure 10, the sublimable dye is ejected from the substrate 11 towards the PSA bare surface structure 16 after the vapor deposition transfer dyeing process ( Figure 2b). Sublimation lamps 19 are arranged near the substrate 11 to heat the substrate 10, thereby sublimating the dye, with some lamps being arranged at an upper position in the enclosure 10 and other lamps being arranged at a lower position. In this way, the lamps 19 are arranged at a position opposite to the PSA exposed surface structure 16 relative to the substrate 1. The lamps 19 in this embodiment are halogen lamps, but are not limited thereto. Any lamps, etc. that can heat the substrate 11 without contact with the substrate can be used.

[0128] The obtained PSA exposed surface structure 16 (such as Figure 2c The illustrated, sublimated toner thereon) is covered by a peelable liner 17 and then transferred to Figure 2c In the illustrated wicking enclosure 21, the substrate 11' deprived of toner can be discarded at the same time.

[0129] Figure 2d The purpose of the imbibition enclosure 7 shown is to fix the dye by heating to / penetrating the PSA bare surface structure 16 on which the coloring agent has sublimated, thereby obtaining a PSA colored structure 14'.

[0130] Preferably, when the PSA bare surface structure 16 covered by the peelable liner layer 17 and on which the colorant is sublimated is introduced into the imbibition box 7, the PSA surface on which the dye is deposited defines the upper surface of the PSA bare surface structure in the enclosure, so that the dye can be fixed on and / or penetrate into the PSA material below it is deposited only with the natural help of gravity, and there is no risk of migrating to the periphery or center of the PSA structure (because the PSA structure is flat), or there is no risk of migration to the periphery or center of the PSA structure (because the PSA structure is flat), or there is no risk of migration to the periphery or center of the PSA structure as shown in the reference. Figure 1c The risk of migration to the bottom surface as anticipated by the described prior art methods, in which the surface of the lens on which the dye is sublimated is the bottom surface in the enclosure.

[0131] refer to Figure 3 , an illustrative embodiment of the invention will be described, relating to the invention described in document WO2020 / 002606, incorporated herein by reference, and in Figure 3 and Figure 4 Functional film structure of the type shown on a, whose PSA layer has been colored according to the method of the invention.

[0132] More specifically, this preferred functional membrane structure includes from top to bottom:

[0133] -Reaction force cushion layer 17

[0134] - Optional liner side sliding layer 22

[0135] - Colored PSA adhesive layer 14'

[0136] - Functional films or HMC stacks (anti-reflection, hard coatings, temporary clamping coatings, films) 15

[0137] - Carrier side sliding layer 23

[0138] - Carrier layer 20

[0139] More specifically, this functional film structure includes a multilayer film surrounded by a carrier layer 20 and a reaction force cushion layer 17. The carrier layer 20 can be made of a composition including polyethylene terephthalate (PET). The thickness of the carrier layer 20 can be in the range of 50μm to 500μm. The reaction force cushion layer 17 can be made of a composition including polyethylene terephthalate (PET) or polyester (PE). The thickness can be in the range of 50μm to 500μm. According to a specific aspect, the reaction force cushion layer 17 includes silicone resin, especially on the side facing the carrier layer 20. The reaction force cushion layer 17 can be a PPI adhesive product sold as PPI 0601 (0.075mm) siliconized polyester film (SILICONISED POLYESTER FILM).

[0140] The functional film 15 extends in a predetermined receiving area between the carrier layer 20 and the counter-force pad layer 17. The functional film may be one layer, or may be formed of a stack of layers.

[0141] The receiving area corresponds to the area immediately surrounding the functional film, which includes space to allow for any small positioning float around the initial positioning of the functional film.

[0142] Functional films can modify the optical, transmission or mechanical properties of an optical article. For example, functional films can provide any of the following: polarization, tint or color filter, hard coating function, anti-reflection function, protective coating and / or surface quality function, or a combination thereof.

[0143] Preferably, the functional film 15 comprises a thermoplastic film having a haze value that is preferably not greater than 0.4%, and once removed from both the carrier layer 20 and the counterforce pad layer 17, and once removed from any protective film intended to be removed once the functional film is present and fixed to the optical article, the functional film as a whole has a haze value that is preferably not greater than 0.4%.

[0144] According to ASTM D1003-00, use Haze-Guard from BYK-Gardner A haze meter (colorimeter) measures haze values ​​by light transmission measurement, which is incorporated herein by reference in its entirety. All references to "haze" values ​​in this application are by this standard. The instrument is first calibrated according to the manufacturer's instructions. Next, the sample is placed on the transmission beam of the pre-calibrated instrument and the haze values ​​are recorded from three different sample positions and averaged.

[0145] The thickness of the functional film 15 may be in the range of 10 μm to 500 μm. The functional film 15 may be made of a composition including polyethylene terephthalate (PET) and / or polycarbonate and / or triacetyl cellulose (TAC, for triacetyl cellulose, France), which may be coated with a hard coating (HC) or an anti-reflection (AR) coating forming a part of the functional film 15.

[0146] Further, the functional film 15 may generally include additional layers capable of achieving some of the above-mentioned functions.

[0147] The carrier layer 20 and the counterforce cushion layer 17 are larger than the receiving area in at least one dimension, and in particular larger than the functional film 15 intended to be present in the receiving area. Figure 3 As shown, the perimeter of the functional film layer 15 is surrounded by the perimeter of the carrier layer 20 and the perimeter of the counterforce pad layer 17. In particular, this enables the carrier layer 20 to be held, fixed or clamped to a machine or device without contaminating, soiling or applying stress to the functional film 15.

[0148] A carrier-side sliding layer 23 may be positioned between the carrier layer 20 and the functional film 15. The carrier-side sliding layer 23 is adapted to enable the positioning floating of the functional film 15 relative to the carrier layer 20. In other words, the carrier-side sliding layer 23 is adapted to reduce the radial stress that would be applied to the functional film if the functional film 15 was too firmly fixed to the carrier layer 20. Considering that during the forming step, there is a maximum height point from the initial plane. The above radial stress will be estimated to extend significantly radially from the maximum height point.

[0149] The thickness of the carrier-side sliding layer 23 may be in the range of 10 μm to 500 μm.

[0150] According to an embodiment, the carrier-side sliding layer 23 may include a double-coated tape with product number 9088 (or also referred to as "high performance double-coated tape 9088 with adhesive 375") provided by 3M Company or any equivalent product.

[0151] According to another embodiment, the carrier side sliding layer 23 may include an acrylic adhesive layer. The carrier side sliding layer may have a total light transmittance of 90% or more, and / or a haze value of 1.0 or less. The carrier side sliding layer may have a dry and wet adhesion property of 25N / 25mm or more according to a test method using the following items:

[0152] - tensiometer,

[0153] - a substrate of corona treated polycarbonate sheet,

[0154] -90° peel angle, and

[0155] -Peeling speed: 25mm / min

[0156] - Backing material: corona treated polyethylene terephthalate film

[0157] - Lamination conditions on polycarbonate sheet: one round trip with a 2 kg roller.

[0158] The acrylic adhesive layer may be sandwiched between two PET release liner layers. According to a test method using a tensile tester, a peeling speed of 0.3 m / min, and a peeling angle of 180°, the peelability of one of the PET release liner layers may be 0.2 N / 50 mm or less, and the peelability of the other PET release liner layer may be 1.0 N / 50 mm or less.

[0159] The cushion layer side sliding layer 22 can be positioned to contact the reaction force cushion layer 17 or a layer fastened to the reaction force cushion layer 17. The cushion layer side sliding layer 22 enables the functional film 15 to float relative to the reaction force cushion layer 17. In other words, the cushion layer side sliding layer 22 is suitable for reducing the radial stress that will be applied to the functional film 15 if the functional film is too firmly fixed to the reaction force cushion layer 17. Considering that during the forming step, there is a maximum height point from the initial plane. The above radial stress will be estimated to extend significantly radially from the maximum height point.

[0160] The backing layer side sliding layer 22 may be made of a composition including polyethylene (PET). Alternatively, the backing layer side sliding layer 22 may be made of a composition that is the same as or similar to the composition of the carrier side sliding layer 23 proposed above. Alternatively, the backing layer side sliding layer may be a pressure sensitive adhesive (PSA) according to PCT application number WO2017168192 filed on March 29, 2016, which is included herein by reference. The PSA further has the characteristics of an optical grade material with a haze value preferably not greater than 0.4%.

[0161] The pad side sliding layer 22 may include a silicone layer on one or both sides. The thickness of the pad side sliding layer 22 may be in the range of 10 μm to 100 μm. In particular, the reaction force pad layer 17 may include a silicone layer at least on the area in contact with the pad side sliding layer 22.

[0162] In some examples, the carrier-side sliding layer 23 is a PSA No. 8141 provided by 3M Company, and the carrier-side sliding layer is provided with a protective sliding film No. SWT10 or SWT 10+R provided by NITTO Company (which can be removed after thermoforming). According to other examples, the carrier-side sliding layer 23 is a PSA No. CS9621 provided by NITTO Company, and the carrier-side sliding layer 23 is provided with a protective sliding film No. SWT10 or SWT 10+R provided by NITTO Company (which can be removed after thermoforming). According to other examples, the carrier-side sliding layer 23 is a PSA No. 9088 provided by 3M Company, also known as high-performance double-sided coated tape 9088 with adhesive 375.

[0163] As shown in the embodiment of FIG. 1 , the multilayer structure may further include an adhesive layer 14 ', such as a pressure-sensitive adhesive (also referred to as a PSA) layer, between the functional film 15 and the backing layer side sliding layer 22 or the reaction force backing layer 17. The adhesive layer 14 'may be made of a composition identical or similar to the composition in the carrier side sliding layer 23 or the backing layer side sliding layer 22 proposed above. According to a preferred embodiment, the adhesive layer 14 'may be a pressure-sensitive adhesive (PSA) according to PCT application number EP 3436210, which is included herein by reference. The PSA further has the characteristics of an optical grade material with a haze value preferably not greater than 0.4%.

[0164] The adhesive layer 14' may be part of the cushion layer-side sliding layer 22. For example, the adhesive layer 14' may be in direct contact with the reaction force cushion layer 17, modulo a possible silicone layer.

[0165] Advantageously, considering the lamination of the functional film 15 on the optical substrate element, before forming the functional film, the surfaces of the first and second elements intended to be placed in contact with the colored adhesive layer 14' according to the invention may be subjected to a surface treatment selected from the following before said contact placement, in accordance with US application No. US2016 / 0216425, incorporated herein by reference: 2 Up to 100W·min / m 2 plasma treatment with a dose range of 40 W·min / m 2 Up to 50W·min / m2 The corona treatment is performed at a dosage of , so that the reduction between the peel force under dry conditions and the peel force under wet conditions is less than or equal to 35% (including the end value).

[0166] More specifically, before the contact placement, the surface of the reaction force pad layer 17 or the pad layer side sliding layer 22 or the protective pad layer intended to be in contact with the colored PSA can be subjected to surface treatment, or the surface of the functional film 15 or the carrier side sliding layer 23 or the second functional film or the substrate optical element intended to be in contact with the colored PSA can be subjected to surface treatment.

[0167] In the example represented, the surface of the base optical element intended to be in contact with the colored PSA receives a corona treatment and the surface of the functional film 15 intended to be in contact with the colored PSA is subjected to a surface treatment before said contact placement with said PSA.

[0168] Considering the lamination of the functional film 15 on the optical base element, before forming the functional film, the counterforce cushion layer 17 is fastened to the carrier layer 20 at least in two different areas, preferably at least three different areas of the counterforce cushion layer 17, according to PCT application number WO 2020002606, which is included herein by reference. The functional film 15 is maintained between the carrier layer 20 and the counterforce cushion layer 17, but preferably has a positioning float due to the carrier-side sliding layer 23 and the cushion layer-side sliding layer 22. Such fastening before forming makes it possible to clearly maintain the position of the functional film 15 relative to the carrier layer 20 and the counterforce cushion layer 17 in the receiving area at a predetermined position at least during thermoforming. For this purpose, fastening means are provided: electrostatic forces resulting from the properties of the material of the counter-force padding layer 17 and / or the carrier layer 20; additional means (such as glue or adhesive) introduced between the counter-force padding layer 17 and / or the carrier layer 20; or can be the result of a process (such as thermoplastic welding) applied to the counter-force padding layer 17 and / or the carrier layer 20. Preferably, the fastening means extend beyond the receiving area.

[0169] In addition to the fastening means, an adhesive layer can fasten the functional film 15 to the carrier layer 20 and / or the reaction force cushion layer in the receiving area. The adhesive layer can be an additional layer, an adhesive layer 14', or a cushion layer side sliding layer or a carrier side sliding layer as a PSA adhesive layer. Such an adhesive layer can maintain the position of the functional film 15 in the receiving area relative to the carrier layer 20 and / or the reaction force cushion layer 17 in a predetermined position before and during thermoforming, thereby further strengthening the effect of the fastening means.

[0170] The adhesive layer is an additional layer, an adhesive layer 14', and / or a backing layer-side sliding layer or a carrier-side sliding layer as an adhesive layer, and it is this adhesive layer that is colored according to the invention and fastens the functional film 15 to the carrier layer 20 and / or the reaction force backing layer in the receiving area.

[0171] In particular, the counterforce pad layer 17 is configured to expand when a positive pressure is applied to the face of the carrier layer 20 opposite the counterforce pad layer 17 .

[0172] When expanded due to the pressure exerted on the carrier layer 20, the counterforce cushion layer 17 exerts a counterforce on the functional film 15 over substantially the entire area of ​​said functional film 15. Thus, delamination of some edges of the functional film 15 is limited or even prevented.

[0173] After shaping, and possibly before shaping, for substantially every area of ​​the reaction force pad layer 17 that is not in contact with the functional film 15 or that does not face the receiving area, the reaction force pad layer 17 can be in contact with the carrier layer 20. According to an embodiment, the fastening between the carrier layer 20 and the reaction force pad layer 17 is substantially all around the receiving area.

[0174] The multilayer film may be thermoformed using a standard thermoforming machine in accordance with PCT Application No. WO 2020 / 002606, which is incorporated herein by reference.

[0175] Furthermore, in accordance with PCT Application No. WO 2020 / 002606, which is incorporated herein by reference, an exhaust system may be used to prevent defects on the multilayer film 2 caused by trapped gases during thermoforming.

[0176] In the present embodiment, the reaction force pad layer 17 may be removed after the forming in consideration of the lamination step.

[0177] In particular, a laminator is used so as to enable the functional film carried by the carrier layer to be laminated onto the optical article. The laminator has a moving element, which is suitable for bringing the thermoformed functional film closer to the optical article and / or for bringing the optical article closer to the thermoformed functional film. Thereafter, the functional film is brought into contact with the optical article. In a specific embodiment, the thermoformed functional film fixed to the carrier layer presents a convex shape and is in contact with the concave surface of the optical article. In another embodiment, the thermoformed functional film fixed to the carrier layer presents a concave shape and is in contact with the convex surface of the optical article. In yet another embodiment, two thermoformed functional films, which respectively present a concave shape and a convex shape, are brought into contact with the convex surface and the concave surface of the optical article, respectively.

[0178] In an embodiment, positive pressure is applied from the side of the carrier to push the functional film onto the face of the optical article.

[0179] The pressure may be maintained for a duration of between 10 seconds and 10 minutes. This makes it possible to ensure that the adhesive layer correctly adheres the functional film to the optical article.

[0180] Thereafter, in some embodiments, a cooling step is applied.

[0181] Finally, the carrier layer is removed from the functional film. If present, the carrier-side sliding layer can also be removed.

[0182] After these last steps, an optical article is obtained, comprising a film fixed on one of its surfaces, free of defects or with reduced defects. At least using the reaction force backing layer, defects are prevented, and in some embodiments, using a possible sliding layer and possible vents, additional defects can be prevented.

[0183] In a particular embodiment, the laminating machine is a thermoforming machine. In another example, the carrier layer is clamped in the same clamping system during both thermoforming and lamination. Possibly the carrier layer can be unclamped to remove the reaction force cushion layer. In such a machine, a cooling step can be applied between thermoforming and lamination.

[0184] According to a specific embodiment, the silicone that may be present on the carrier layer and / or the counterforce pad layer may be silicone provided by Siliconature under the product number SILPHAN S50.

[0185] According to various embodiments, the carrier side of the counter-force pad layer may be in direct contact with the functional film or one of the layers on top of the functional film that is intended to be present on the optical article and is intended to bring functionality to the optical article.

[0186] PSA coloring experiments and results

[0187] An illustrative example and some steps illustrating the invention and key results are provided below.

[0188] Printing steps

[0189] Different inks or dyes are commercially available, sublimable, usable in ophthalmic articles, and compatible with the selected substrate material (eg, polycarbonate) in three primary colors: red, yellow, and blue, and are typically comprised of water-based solutions.

[0190] The step of printing the dye onto the transfer paper according to a specific recipe may last 2 minutes and dry for 10 minutes.

[0191] Surface preparation

[0192] The preferred functional film structure 13 is provided with a PSA layer 14 sold by Nitto under the number EL5902RT and having a thickness of 50 micrometers, which is a PSA in contact with the functional film 15 and is intended to be in contact with the optical substrate element after the preferred functional film structure is applied to the optical substrate element. The preferred functional film structure 13 comprises a multilayer functional film 15 (which is provided with a hard coating layer and an anti-reflection layer), a carrier-side sliding layer 23, and a carrier 20, such as Figure 3 As depicted in .

[0193] In order to maximize the adhesion of the PSA layer 14 intended to be colored with a sublimable dye, the two surfaces that will come into contact with the colored PSA (i.e., on the one hand, the surface of the optical substrate element on which the functional film structure is intended to be applied, and on the other hand, the surface of the functional film 15 of the functional film structure 13) and / or the two surfaces of the PSA itself will be the object of a surface treatment (such as a corona treatment).

[0194] More precisely, corona treatment according to U.S. application No. US 2016 / 0216425, included herein by reference, is applied on the one hand to the surface of the optical substrate element intended to be in contact with the PSA layer to be colored, and on the other hand to the surface of the multifunctional film 15 comprising a hard coating and an antireflection layer intended to be in contact with the PSA layer to be colored, and / or to both surfaces of the PSA itself.

[0195] Sublimation steps

[0196] like Figure 2b As disclosed, the counterforce liner layer 17 is removed from the PSA layer to be colored to obtain a PSA bare surface structure 16 consisting of the PSA layer 14 , the monolayer or multilayer structure 15 , the second peelable liner layer and / or the supporting film or carrier 20 .

[0197] The sublimation step was carried out at the following temperature: 55° C. (related to the sublimation lamp), pressure: vacuum (greater than or less than 0.1 kPa), wherein the sublimation operation cycle was 6 min.

[0198] After the sublimation step, according to Figure 2c , a PSA bare surface structure 16 is obtained, on which a colorant is sublimated, and the colorant is laid on the surface of the PSA layer.

[0199] Then, a counter force backing layer 17 is applied on the surface of the colored PSA layer surface 14 to protect it during its transfer to the imbibition enclosure 7 ( Figure 2d ).

[0200] Imbibition Steps

[0201] like Figure 2dAs shown, after the protected colored PSA layer surface 14' structure is subjected to an imbibition step in an oven at 90°C for 10 minutes, the sublimated coloring dye or coloring agent is fixed to the PSA layer surface and / or penetrates the thickness of the PSA layer, thereby obtaining a PSA colored structure 14'.

[0202] After thermoforming, the counterforce backing layer 17 is removed before the functional multilayer structure 15 is applied via the PSA pigmented structure 14 ′ onto the corona-treated surface of the optical substrate element by lamination.

[0203] Thermoforming and lamination steps

[0204] The pressure applied can reach 2 or 3 bar.

[0205] The pressing step is performed with a temperature applied to the film of about 25° C. to 80° C. The temperature for thermoforming may also be between 80° C. and 140° C., such as 100° C. to 130° C., such as 115° C. to 125° C., or about 120° C., with the maximum temperature depending on the base film material, its thickness, and the final target curvature of the film / lens.

[0206] The pressure is maintained for a duration of between 10 seconds and 10 minutes. This makes it possible to ensure that the adhesive layer correctly adheres the functional film to the optical article.

[0207] Thereafter, a cooling step is performed.

[0208] Finally, the carrier layer is removed from the functional film. If present, the carrier-side sliding layer can also be removed.

[0209] After these last steps, an optical article is obtained, comprising a film fixed on one of its surfaces, free of defects or with reduced defects. At least using the reaction force backing layer, defects are prevented, and in some embodiments, using a possible sliding layer and possible vents, additional defects can be prevented.

[0210] exist Figure 2gβ In the illustrated embodiment, the functional film is applied to the convex surface of the lens having a radius of curvature of 81 mm. The functional film is thermoformed to have a radius of curvature of 81 mm.

[0211] The adhesive layer 14 is a PSA adhesive sold by Nitto under the name EL5902RT.

[0212] PSA thickness: 50μm

[0213] The reaction force cushion layer is an adhesive product provided by PPI with the number of PPI 0601 (0.075 mm) siliconized polyester film (SILICONISED POLYESTER FILM).

[0214] Peel test

[0215] The peel test consists of rolling a 25×70mm strip of pressure-sensitive adhesive material onto a protective film strip. This tape (protective film + adhesive material) is glued to a planar support on which a film is pre-fixed. This test makes it possible to test the adhesion between the film and the protective film. Before peeling, the glass is kept in the same condition for at least 24h (at 23°C ± 3°C, 50% RH ± 10%). The film is peeled at a speed of 2.54cm / min at an angle of 90°. At halfway through the test, a certain amount of water is added to the interface to measure the wet coating force. The force is expressed in N / 25mm. The software continuously measures the peel force as a function of displacement. For dry and wet peeling, this force is averaged over a length of 10mm to 20mm.

[0216] The samples were then washed, coated and finally trimmed with a Kappa (trade name) trimmer. Once trimmed, the samples were checked to determine if there were cosmetic defects, such as separation between the films in the polarizing structure. When the stack presented defects, this was indicated by a cross in the 'Lens Manufacturing' column of the table. When the trimming did not present any defects, this was indicated by 'OK' in the same column.

[0217] Peel Test and Results

[0218] Two series of tests (A and B) were run with the formulations as indicated in Table 1 .

[0219]

[0220] Table 1. Sublimation empirical conditions to define imbibition time for Series A and Series B respectively.

[0221] In a first series (A), the fact of having an imbibition step or not was evaluated, as disclosed in Table 2 below. Two conditions were set: no imbibition step and an imbibition step during 1 h at low temperature (90° C.) (it is known that HMC stacks can withstand temperatures above 100° C.) to avoid cracking of the anti-reflection stack on the consumables.

[0222] In the second series (B), medium wicking times at 90°C were tested. The results of the peel force show (Table 2) that wicking of 10 to 20 minutes is sufficient to be in the safe zone in terms of adhesion (dry and wet peel forces> 20 N / 25 mm), and that dry and wet adhesion are the same. The possible optimum for wicking will be around 20 minutes, when 25 N / 25 mm is reached. For very dark shades (category 3 and 4), longer wicking times may be required to fix the dye, and the skilled person can easily determine this wicking time based on the study of the color change that occurs after several days compared to the color initially deposited.

[0223]

[0224] Table 2. Peel test results for Series A and Series B.

[0225] The peel force results for Series A (Table 2) show that without wicking, the peel force adhesion is reduced (16 N / 25 mm without wicking vs. 22 N / 25 mm for 1 h at 90°C), but the dry and wet peel forces are the same, which is a good result.

[0226] Figure 4 The peel force results for PSA without dye (left side) and PSA + dye (other side) and at different wicking times under dry and wet conditions are shown. The dashed line corresponds to the minimum adhesion from previous studies on lamination technology. The solid line corresponds to the maximum adhesion of PSA without dye.

[0227] Figure 4 It is shown that when the dye is sublimated onto the PSA some adhesion is lost (29 N / 25 mm without dye vs. 25 N / 25 mm with dye), but the adhesion of 25 N / 25 mm achieved in the presence of the dye is considered very good.

[0228] Effect of the distance between PSA and transfer paper

[0229] During the sublimation step, the PSA layer 14 is in a flat form and the transfer paper is also in a flat form, allowing the distance between the two objects to be reduced and a darker lens to be obtained with the same dye amount in the toner solution formulation than the lens obtained when the bent lens receives the sublimated dye. For example, for the same dye amount in the toner solution formulation, when the bent lens receives the sublimated dye, a Tv of ˜15% is obtained, while when the PSA layer 14 receives the sublimated dye, a darker color with a Tv of ˜10% is obtained.

[0230] This was confirmed by running sublimation tests with the ink formulation according to Table 3:

[0231] -First sublimation with two pairs of biplano lenses vs. plano / curved lenses

[0232] - Second sublimation with three pairs of biplano lenses against PSA consumables

[0233] For these tests, the wicking time of the PSA consumables was fixed at 1 h at 90 ° C. In order to be able to measure the transmission spectra of the PSA consumables colored by sublimation, the PSA patches of the consumables were glued on biplano lenses (without non-optical elements such as carriers, backing layers, ...). In order to avoid confusion, in Table 3, the PSA consumables are mentioned even if they are glued to biplano lenses for handling purposes. The "biplano lenses" in the table refer to biplano lenses colored by sublimation with a standard sublimation method.

[0234]

[0235] Table 3. Ink formulations used to demonstrate that darker final lenses are obtained with the same dye amount in a flat support (biplano lens or plano PSA film) than with a curved plano lens.

[0236] The results shown in Table 4 represent the Tv and color (a*, b*) obtained on biplano lenses, plano / curved lenses, and flat PSA consumables.

[0237] Correspondingly, for the same amount of dye on the transfer paper, a darker lens (Tv between 7.5%-9.4%, with 8.6 for flat PSA film) was always obtained when the toner was sublimated onto a biplano lens or a flat PSA film, whereas a lighter lens (Tv ~ 15%) was obtained when a plano curved lens was used. This is probably due to the fact that the transfer paper is flat, and if the toner is sublimated from a flat support onto an equally flat substrate (biplano lens or PSA film), the two elements can be brought closer (printed paper and biplano lens or flat PSA film) and the amount of dye needed on the paper to obtain a given transmittance is reduced compared to the amount of dye needed for the standard sublimation process from flat printed paper onto a curved lens.

[0238] Dispersibility at the coloring step (without hard coating step)

[0239] As demonstrated in Tables 4 and 5 below, the scatter of the sublimation process steps is very similar between sublimation on curved lenses and sublimation on flat PSA films.

[0240]

[0241] Table 4. Ink formulations used to demonstrate that the dispersion of the sublimation process step is very similar between sublimation on curved lenses or sublimation on flat PSA films.

[0242]

[0243] Table 5. Dispersion results on PSA consumables and plano curved lenses.

[0244] Testing of different colors and surface treatments

[0245] Several prototypes in different colors have been laminated to bi-matte and edge grinding has been completed. Some samples have been edged and no edge defects have been observed. Tinted consumables have also been laminated to curved lenses and the edge grinding results are good.

[0246] Coloring Type

[0247] Different types of coloring can be obtained: complete and uniform coloring, gradient coloring, specific patterns like logos or markings (obtained by using a specific mask applied on the PSA surface during the sublimation step).

[0248] advantage

[0249] The present invention achieves the goal of providing any sunglass color with a fast delivery technology, since the consumables are tinted with a fast tinting process (~15 minutes), compared to known solutions that require about 3 hours to tint lenses or films. In addition, the tinting of the consumables can be carried out in parallel with the surface treatment of the lenses, without adding additional time to the manufacturing process, and the final tint is obtained during the lamination of the functional film on the back and / or front side of the lens, i.e. without adding specific additional steps that would prolong the lamination process.

[0250] Furthermore, the method according to the invention allows reduced energy consumption compared to standard sublimation onto lenses, since the duration required for the imbibition step on the PSA layer is almost 10 to 20 times shorter, since the PSA is soft and a better matrix for the dye than the lens (10 to 20 minutes of imbibition at 90°C are sufficient to ensure good adhesion, whereas in standard sublimation processes the imbibition cycle of the dye on the lens is between 1 hour 30 minutes and 3 hours at high temperatures of 125°C to 160°C to ensure penetration of the dye into the interior of the hard lens substrate).

[0251] Furthermore, due to the present invention, the following other advantages are observed:

[0252] - Less complexity:

[0253] Tooling simplification: Instead of requiring specific tooling for each lens geometry, only one tooling system optimized for flat PSA films is needed

[0254] Simplified formulation / pattern printing, regardless of lens substrate or power. In fact, for a given color, only one dye formulation optimized for a flat PSA film is now needed, whereas conventional methods require different formulations / pattern printings, each for different optical powers, to ensure uniformity between the center and the edge of a curved lens receiving sublimated dye on its curved surface.

[0255] - From a quality point of view, metamerism between substrate and dispersion is eliminated due to the hard coating process

[0256] - Generally, there is no wet chemistry involved in the process and it is possible to automate it (inline two-part process).

[0257] - Reduced dye consumption due to the fact that the dye sublimation step is carried out from a flat paper to a flat PSA film and not to a curved lens. In fact, the distance between the flat sublimation paper and the flat film can be the same and reduced to a minimum, thus reducing dye consumption, since the greater the distance, the more the dye tends to migrate to other parts of the vacuum chamber (e.g. the walls) instead of moving towards the support to be tinted. Furthermore, compared to conventional sublimation on lens methods, dye losses are prevented during the imbibition step, since during the imbibition step according to the invention the dye is confined between the backing layer / PSA and the TAC

[0258] - For a given color, only one dye recipe can be sublimated onto the same PSA layer, which can then be applied to any kind of substrate. Accordingly, the same spectrum and color appearance is obtained for different substrates. In contrast, in standard sublimation processes, different dye recipes are required for different substrates, because their chemical properties and coloring abilities are different (e.g.: polycarbonate and 1.6 substrate). As a result, in addition to the complexity caused by different recipes for the same color, the spectral curves for the same color reference also differ from substrate to substrate. This leads to metamerism

[0259] - In case of sublimation onto PSA, the color applied to the PSA is defined, since no further hard coating process is required (the hard coating is already on the film).

Claims

1. A functionalized optical layered structure, comprising: - a first element, said first element representing a first single-layer or multi-layer functional film (15); - at least one second element, the at least one second element is selected from a protective backing layer, or a base optical element (1), or a second functional film at least one pressure-sensitive adhesive layer placed in contact with at least one surface of the first element and at least one surface of the second element, Therein, the at least one pressure-sensitive adhesive layer (14') is of optical quality and comprises a colorant (12).

2. The functionalized optical layered structure according to the preceding claim, wherein: The toner (12) includes a sublimable, printable, sprayable or inkjettable toner.

3. The functionalized optical layered structure according to any one of the preceding claims, wherein: The second element is a base optical element (1), and wherein the at least one pressure-sensitive adhesive layer (14') defines a peel force when dry and a peel force when wet, each higher than 13N / 25mm, to separate the first element (15) from the base optical element (1).

4. The functionalized optical layered structure according to the preceding claim, wherein: The pressure-sensitive adhesive layer (14') has a peel force when dry and a peel force when wet that decreases by no more than 35%.

5. The functionalized optical layered structure of any one of the preceding claims, wherein: The storage modulus G' of the pressure-sensitive adhesive layer (14') at 85°C is less than 1.6×10 5 Pa, preferably less than or equal to 1.5×10 5 Pa, and the dry peel strength and wet peel strength exhibited by the pressure-sensitive adhesive layer are both higher than 20N / 25mm, preferably both in the range of 21N / 25mm to 40N / 25mm, including end values.

6. A functionalized optical article, comprising a substrate element (1) and a functionalized optical layered structure applied to one surface of the substrate element, wherein the functionalized optical layered structure comprises: - a first element, said first element representing a first single-layer or multi-layer functional film (15); - at least one second element, the at least one second element is selected from a protective backing layer, or a base optical element (1), or a second functional film at least one pressure-sensitive adhesive layer placed in contact with at least one surface of the first element and at least one surface of the second element, Therein, the at least one pressure-sensitive adhesive layer (14') is of optical quality and comprises a colorant (12).

7. An eyewear device, comprising a support structure such as a frame and at least one functionalized optical article enclosed within the support structure and edged according to the size of the support structure, the functionalized optical article comprising a base element and a functionalized optical layered structure applied to the base element, the functionalized optical layered structure comprising: - a first element, said first element representing a first single-layer or multi-layer functional film (15); - at least one second element, the at least one second element is selected from a protective backing layer, or a base optical element (1), or a second functional film at least one pressure-sensitive adhesive layer placed in contact with at least one surface of the first element and at least one surface of the second element, Therein, the at least one pressure-sensitive adhesive layer (14') is of optical quality and comprises a colorant (12).

8. A method for manufacturing a functionalized optical layered structure, the method comprising the following steps: - providing a functionalized optical layered structure, the functionalized optical layered structure comprising: - a first element, said first element representing a first single-layer or multi-layer functional film (15) - at least one pressure-sensitive adhesive layer Wherein the at least one pressure-sensitive adhesive layer (14') is of optical quality, and wherein the method comprises the step of coloring at least one surface of the at least one pressure-sensitive adhesive layer with a coloring agent (12).

9. The method according to the preceding claim, wherein: The step of coloring the at least one pressure-sensitive adhesive layer is a sublimation step, wherein the colorant (12) is sublimable, and wherein, during the sublimation step, the at least one pressure-sensitive adhesive layer is in a flat form and the colorant transfer support facing the at least one pressure-sensitive adhesive layer is in a flat form.

10. The method according to the preceding claim, wherein: The distance between the toner transfer support and the at least one pressure-sensitive adhesive layer is lower than 15 mm, preferably lower than 12 mm and preferably higher than 5 mm.

11. A method as claimed in any one of the preceding claims 6 to 8, comprising an imbibing step to fix the colouring agent to the at least one pressure-sensitive adhesive layer after the colouring step.

12. The method according to the preceding claim, wherein: During the imbibing step, the at least one pressure-sensitive adhesive layer is disposed such that a surface of the at least one pressure-sensitive adhesive layer on which the toner is deposited constitutes an upper surface of the at least one pressure-sensitive adhesive layer.

13. The method according to the preceding claim, wherein: The imbibition step includes heating the at least one pressure-sensitive adhesive layer at a temperature and for a time that allows softening without melting the at least one pressure-sensitive adhesive layer, for example, less than 1 hour and less than 90°C, preferably 10 minutes and less than 90°C, so that the colorant is fixed on the surface of the at least one pressure-sensitive adhesive layer and / or penetrates the thickness of the at least one pressure-sensitive adhesive layer.

14. The method according to the preceding claim, wherein: The heating step comprises heating the at least one pressure sensitive adhesive layer by air convection or by surface irradiation.

15. A method for manufacturing a functionalized optical article, the method comprising: i. A step of thermoforming the functionalized optical layered structure according to the curvature of the substrate element (1), the functionalized optical layered structure comprising:

1. A first element, said first element representing a first single-layer or multi-layer functional film (15); 2. At least one second element, the at least one second element is selected from a protective liner layer or a second functional film 3. At least one pressure-sensitive adhesive layer (14') placed in contact with at least one surface of the first element and at least one surface of the second element, the at least one pressure-sensitive adhesive layer having optical quality and comprising a coloring agent (12) ii. The step of fixing the thermoformed functionalized optical layered structure on the substrate element.

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