Optical film and optical lens including the same

Abstract

The optical film includes a plurality of alternating first and second polymer layers disposed on a first protective layer. Each of the first and second polymer layers has an average thickness less than about 500 nm, and the first protective layer has an average thickness greater than about 750 nm. An olefin layer can be disposed on the first protective layer opposite the plurality of alternating first and second polymer layers. The olefin layer includes a cyclic olefin copolymer, a cyclic olefin polymer, or a blend thereof. The olefin layer can have an unstructured major surface opposite the first protective layer. A tie layer is disposed between the olefin layer and the first protective layer and bonds the olefin layer and the first protective layer to each other. The optical film is integrally formed.

Description

Summary of the Invention

[0001] In some embodiments, the present disclosure provides an optical film comprising a plurality of alternating first and second polymer layers disposed on a first protective layer. Each of the first and second polymer layers has an average thickness of less than about 500 nm, and the first protective layer has an average thickness of more than about 750 nm. An olefin layer can be disposed on the first protective layer opposite the plurality of alternating first and second polymer layers. The olefin layer comprises a cyclic olefin copolymer, a cyclic olefin polymer, or a blend thereof. The olefin layer can have an unstructured major surface opposite the first protective layer. A tie layer is disposed between the olefin layer and the first protective layer, bonding the olefin layer and the first protective layer to each other. The optical film is integrally formed.

[0002] In some embodiments, the present disclosure provides an optical film comprising a plurality of alternating first and second polymer layers disposed on a first protective layer. Each of the first and second polymer layers has an average thickness of less than about 500 nm, and the first protective layer has an average thickness of more than about 750 nm. An olefin layer can be disposed on the first protective layer on the opposite side of the plurality of alternating first and second polymer layers. The olefin layer can include a cyclic olefin copolymer, a cyclic olefin polymer, or a blend thereof. A tie layer is disposed between the olefin layer and the first protective layer, and bonds the olefin layer and the first protective layer to each other. The composition of the tie layer can be different from the composition of each of the first protective layer and the first and second polymer layers. The optical film is integrally formed.

[0003] In some embodiments, the present disclosure provides an optical film comprising a plurality of alternating first and second polymer layers disposed on a first protective layer. Each of the first and second polymer layers has an average thickness of less than about 500 nm, and the first protective layer has an average thickness of more than about 750 nm. An ethylene copolymer layer can be disposed on the first protective layer on the opposite side of the plurality of alternating first and second polymer layers. The optical film is integrally formed.

[0004] The present disclosure provides, in some embodiments, a method for manufacturing an optical lens. The method includes providing an integrally formed optical film comprising a plurality of alternating first and second polymer layers disposed on a first protective layer, each of the first and second polymer layers having an average thickness less than about 500 nm, and the first protective layer having an average thickness greater than about 750 nm. An olefin layer is disposed on the first protective layer opposite the plurality of alternating first and second polymer layers. The olefin layer comprises a cyclic olefin copolymer, a cyclic olefin polymer, or a blend thereof. A tie layer is disposed between the olefin layer and the first protective layer, bonding the olefin layer and the first protective layer to each other. The method includes forming a lens substrate on the optical film such that the lens substrate faces the olefin layer and bonds to the olefin layer. The lens substrate comprises an olefin composition.

[0005] These and other aspects will become apparent from the following detailed description, but in no way should this brief summary be construed as limiting the claimed subject matter. [Brief description of the drawings]

[0006] [Figure 1] 1 is a schematic cross-sectional view of an optical film according to some embodiments. [Diagram 2] 1 is a schematic cross-sectional view of an optical film according to some embodiments. [Diagram 3]1 is a schematic cross-sectional view of an optical lens according to some embodiments. [Figure 4] 1 is a schematic diagram of a method for manufacturing an optical lens, according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] In the following description, reference is made to the accompanying drawings, which form a part hereof, and in which various embodiments are shown by way of illustration. The drawings are not necessarily to scale. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present disclosure. Accordingly, the following detailed description is not to be taken in a limiting sense.

[0008] An optical system can include one or more optical lenses that include an optical film disposed on a lens substrate. For example, the optical system described in U.S. Pat. No. 9,557,568 (Ouderkirk et al.) includes an optical lens with, for example, a reflective polarizer film disposed on a lens substrate. In some embodiments, it is desirable for the lens substrate to be formed from an olefin, such as a cyclic olefin copolymer (COC) or a cyclic olefin polymer (COP), at least in part because such materials have low birefringence. However, it can be difficult to achieve a suitable bond between such lens substrates and typical materials used in multilayer optical films, such as polyester. According to some embodiments, it has been found that an optical film can include an outer layer that bonds well to such lens substrates and an additional bonding layer that bonds the outer layer to another layer of the optical film. According to some embodiments, it has been found that the materials for the outer layer, bonding layer, and other layers of the optical film can be selected so that the film can be integrally formed, for example, by coextrusion and costretching.

[0009] FIG 1 is a schematic cross-sectional view of an optical film 150 according to some embodiments. FIG 2 is a schematic cross-sectional view of an optical film 150' according to some other embodiments. The optical film 150, 150' includes a plurality of alternating first polymer layers (21) and second polymer layers (22) 20 disposed on a first protective layer 24. In some embodiments, the optical film 150, 150' includes an olefin layer 28 disposed on the first protective layer 24 opposite the plurality of alternating first and second polymer layers 20, and includes a tie layer 26 disposed between and bonding the olefin layer 28 and the first protective layer 24 to one another.

[0010] In some embodiments, each of the first and second polymer layers has an average thickness of less than about 500, 400, 350, 300, 250, or 200 nm. The average thickness may be, for example, at least about 20 nm or at least about 40 nm. For example, in some embodiments, each of the first and second polymer layers has an average thickness ranging from about 20 nm to about 500 nm, or from about 40 nm to about 400 nm. In some embodiments, the first protective layer 24 has an average thickness of, for example, greater than about 750, 1000, 1500, or 2000 nm. The average thickness can be, for example, up to about 30 micrometers or up to about 20 micrometers. In some embodiments, for example, each of the first and second polymer layers has an average thickness of less than about 500 nm, and the first protective layer has an average thickness of greater than about 750 nm. In some embodiments, tie layer 26 has an average thickness of about 0.5-20 microns, or about 1-10 microns, or about 1.5-8 microns. In some embodiments, tie layer 26 has an average thickness greater than the average thickness of the first polymer layer and the second polymer layer. In some embodiments, tie layer 26 has an average thickness greater than the average thickness of first protective layer 24.

[0011] In some embodiments, the number of the multiple alternating first polymer layers and second polymer layers is at least 10, 20, 50, 75, 100, 150, 200, 250, 300, 350, or 400 in total. The number of the multiple alternating first polymer layers and second polymer layers may be, for example, up to 1500 or 1000 in total. For example, the number of the multiple alternating first polymer layers 21 and second polymer layers 22 may be 10 to 1500 or 20 to 1000 in total.

[0012] The optical film 150, 150' can include additional layers. For example, the optical film can include a second protective layer 24' disposed on the plurality of alternating layers 21, 22 on the opposite side from the first protective layer 24. The optical film can further include one or more additional layers 25 disposed between the plurality of sub-divided alternating layers 21, 22, as shown diagrammatically in FIG. 2. It will be understood by those skilled in the art that the one or more additional layers 25 (and layers 24, 24') can be protective boundary layers. Each of the one or more additional layers 25 and / or the second protective layer 24' can have an average thickness in any of the ranges described for the first protective layer 24.

[0013] In some embodiments, the tie layer 26 includes multiple sublayers. For example, the tie layer 26 can include a sublayer 26a for bonding to the olefin layer 28 and a sublayer 26b for bonding to the first protective layer 24. The multiple sublayers can include only two sublayers or can include more than two sublayers. In some embodiments, the tie layer 26 is a single monolithic layer that can directly contact the olefin layer 28 and the first protective layer 24.

[0014] In some embodiments, the olefin layer 28 has an unstructured major surface 281 opposite the first protective layer 24. The unstructured major surface generally does not include structures (e.g., microstructures) created on the surface, for example, for optical or mechanical purposes, but may include marks or other features resulting from normal manufacturing processes. The unstructured major surface may be characterized in terms of surface roughness and / or in terms of haze. In some embodiments, the unstructured major surface 281 has an average peak-to-valley (PV) surface roughness Rz of less than about 2, 1.5, 1, 0.5, 0.4, 0.3, 0.2, or 0.1 micrometers. In some embodiments, the optical film 150, 150' has a transmission haze of less than 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, or 1 percent. Transmission haze can be measured, for example, according to ASTM D1003-13 test standard.

[0015] The protective layer may have the same composition as one of the first and second polymer layers. Suitable materials for the various layers include, for example, polyethylene naphthalate (PEN), coPEN (copolyethylene naphthalate terephthalate copolymer), polyethylene terephthalate (PET), polyhexylethylene naphthalate copolymer (PHEN), syndiotactic polystyrene (sPS), glycol-modified PET (PETG), glycol-modified PEN (PENG), coPET polycarbonate alloy, various other copolyesters as described elsewhere herein, polyolefins, polymethyl methacrylate (PMMA), coPMMA (copolymer of methyl methacrylate and ethyl acrylate), other acrylics, or blends thereof. Other suitable materials for the various layers include those described, for example, in U.S. Pat. Nos. 5,103,337 (Schrenk et al.), 5,540,978 (Schrenk), 5,882,774 (Jonza et al.), 6,179,948 (Merrill et al.), 6,207,260 (Wheatley et al.), 6,783,349 (Neavin et al.), 6,967,778 (Wheatley et al.), 9,069,136 (Weber et al.), and 9,162,406 (Neavin et al.).

[0016] In some embodiments, at least one of the first and second polymer layers comprises a polymer containing naphthalate groups (e.g., PEN or coPEN). In some embodiments, at least one of the first and second polymer layers comprises a polymer containing terephthalate groups (e.g., PET or coPET). In some embodiments, the first polymer layer is birefringent and the second polymer layer is substantially optically isotropic. The birefringent layer can comprise a polymer containing naphthalate and / or terephthalate groups. The substantially isotropic layer can comprise, for example, a polyester, a copolyester, or a polycarbonate / copolyester alloy. Additionally or alternatively, the protective layer can be formed from any of these materials. Such materials have been found to bond well to the tie layers described elsewhere herein, which can bond well to the olefin layer.

[0017] The birefringent layer can have a maximum birefringence (e.g., absolute value of the refractive index difference in the x- and z-directions) of, for example, greater than about 0.05, 0.08, 0.1, 0.12, or 0.15 at a first wavelength (e.g., 532 nm, 550 nm, or 633 nm) in a wavelength range of about 400 nm to about 700 nm. The substantially isotropic layer can have a maximum birefringence of, for example, less than about 0.025, 0.02, 0.015, 0.01, or 0.005 at the first wavelength. The birefringent layer can have a refractive index along at least one direction that is, for example, at least about 0.05, 0.08, 0.1, 0.12, or 0.15 greater than the refractive index of the substantially isotropic layer, at least for the first wavelength. The maximum difference in refractive index between different layers along the same direction, or between different directions within the same layer, can be, for example, up to about 0.5, 0.4, or 0.3 at the first wavelength.

[0018] In some embodiments, the tie layer 26 has a glass transition temperature (Tg) of less than about -100°C or less than about -120°C. In some such embodiments, or in other embodiments, the tie layer has a melting point of greater than about 100°C or greater than about 120°C. For example, the tie layer 26 can have a glass transition temperature of less than about -100°C and a melting point of greater than about 100°C. In some embodiments, the olefin layer 28 has a glass transition temperature in the range of 100°C to 115°C or 105°C to 110°C. Having the Tg of the olefin layer 28 within these ranges aids in the processability of the film. For example, in some processing methods, a Tg that is too low may cause the film to stick to tenter clips, and a Tg that is too high may cause the film not to orient as desired and not develop the desired optical properties. The glass transition temperature can be measured, for example, by differential scanning calorimetry according to standard ASTM E1356-08 (reapproved 2014).

[0019] In some embodiments, the tie layer 26 (and / or other layers of the optical film 150, 150') has a weight average molecular weight of greater than about 20,000, 30,000, 40,000, or 50,000 Daltons, or within the ranges described elsewhere herein. In some embodiments, the composition of the tie layer 26 is different from the composition of the first protective layer 24 and the first and second polymer layers 21, 22, respectively. The tie layer 26 can be or include an ethylene copolymer. The ethylene copolymer can include, for example, one or more of styrene, acrylic, vinyl, or maleic anhydride groups. Suitable ethylene copolymers include, for example, those available under the KRATON trade name from KRATON Corporation (Huston, TX) and those available under the BYNEL and ELVALOY trade names from Dow Chemical (Midland, MI). The layer 26 can be or include, for example, a PETG layer. Suitable PETG includes, for example, GN071 available from Eastman Chemical (Kingsport, Tenn.).

[0020] In some embodiments, the optical film 150, 150' includes an ethylene copolymer layer 26 disposed on the first protective layer 24 opposite the plurality of alternating first and second polymer layers 21 and 22 (20). In some embodiments, the optical film 150, 150' further includes an olefin layer 28, with the ethylene copolymer layer 26 bonding the olefin layer and the first protective layer to one another. The ethylene copolymer layer 26 can include an ethylene copolymer, as further described elsewhere herein.

[0021] The olefin layer 28 can include, for example, a cyclic olefin copolymer (COC), a cyclic olefin polymer (COP), or blends thereof. Suitable olefin polymers and copolymers for the olefin layer 28 and / or lens substrate 220 (see, for example, FIG. 3) include, for example, those available under the tradename TOPAS from TOPAS Advanced Polymers GmbH (Raunheim, Germany) and those available under the tradename ZEONOR from Zeon Specialty Materials, Inc. (San Jose, Calif.).

[0022] The materials of the various layers can be selected to obtain high peel strength. In some embodiments, the optical film has an average peel strength of more than about 100, 200, 300, 500, 1000, 1500, 2000, 3000, 4000, 4500, or 5000 g / inch. In some embodiments, the peel strength is so high that the layers of a 1-inch wide film strip cannot be peeled using a 10-pound load cell. The peel strength is measured using a 90-degree peel with a pulling speed of 12 inches / minute, unless otherwise indicated. In some embodiments, an optical film having an average interlayer peel force in any of these ranges is formed from a plurality of alternating first and second polymer layers disposed on a first protective layer, and a tie layer disposed on the first protective layer opposite the plurality of alternating first and second polymer layers, each of the first polymer layers comprising a polymer comprising a naphthalate group and / or a terephthalate group, each of the first protective layer and the second polymer layer comprising a polyester, a copolyester, or a polycarbonate / copolyester alloy, and the tie layer comprising an ethylene copolymer. The polyester, copolyester, or polycarbonate / copolyester alloy of the first protective layer may have the same or different composition as the polyester, copolyester, or polycarbonate / copolyester alloy of the second polymer layer. The ethylene copolymer may comprise one or more of a styrene group, an acrylic group, a vinyl group, or a maleic anhydride group.

[0023] In some embodiments, each layer of the optical film 150, 150' is formed from a thermoplastic polymer. The thermoplastic polymer can be selected to be easily extrudable and processable. For example, the thermoplastic polymer can be selected to have a molecular weight and / or intrinsic viscosity and / or melt flow index (MFI) within a range suitable for extrudability. In some embodiments, each of the thermoplastic polymers has a weight average molecular weight Mw of more than 20,000 Daltons, or more than 30,000 Daltons, or more than 40,000 Daltons, or more than 50,000 Daltons. For example, the weight average molecular weight Mw can be, for example, up to 1,000,000 Daltons, or up to 600,000 Daltons, or up to 400,000 Daltons, or up to 200,000 Daltons, or up to 150,000 Daltons. In some such embodiments, or in other embodiments, each of the thermoplastic polymers has an intrinsic viscosity in the range of 0.3 dl / g to 1.2 dl / g or 0.4 dl / g to 1.0 dl / g, as measured in a solvent blend containing 60 weight percent o-chlorobenzene and 40 weight percent phenol. In some such embodiments, or in other embodiments, the thermoplastic polymer has a melt flow index greater than 5 g / 10 min, or greater than 10 g / 10 min, or greater than 20 g / 10 min. The melt flow index may be, for example, up to 300 g / 10 min, or up to 200 g / 10 min, or up to 100 g / 10 min. The weight average molecular weight Mw may be measured, for example, using gel permeation chromatography. The intrinsic viscosity may be measured, for example, using a capillary viscometer. The melt flow index may also be referred to as melt flow rate, and may be measured, for example, using an extrusion plastometer according to ASTM D1238-20.

[0024] The optical films 150, 150' may be integrally formed. As used herein, a first element "integrally formed" with a second element means that the first and second elements are manufactured together, rather than being manufactured separately and then bonded. Integral forming includes manufacturing the first element and then manufacturing the second element on the first element. An optical film including multiple layers is integrally formed when the layers are manufactured together (e.g., combined as a melt stream and then cast on a chill roll to form a cast film having each layer, and further orienting the cast film) rather than being manufactured separately and then bonded. In some embodiments, all layers of the optical films 150, 150' are coextruded. In some embodiments, all layers of the optical films 150, 150' are further costretched.

[0025] As known in the art, multilayer optical films that include alternating polymer layers can be used to obtain desired reflectance and transmittance within desired wavelength ranges by appropriately selecting layer thickness and refractive index difference.Multilayer optical films and methods for manufacturing multilayer optical films are described in, for example, U.S. Patent No. 5,882,774 (Jonza et al.), U.S. Patent No. 6,783,349 (Neavin et al.), U.S. Patent No. 6,949,212 (Merrill et al.), U.S. Patent No. 6,967,778 (Wheatley et al.), and U.S. Patent No. 9,162,406 (Neavin et al.).

[0026] In some embodiments, the optical film 150, 150' is a reflective polarizer. In some embodiments, for substantially normally incident light 140 (e.g., an angle of incidence less than about 30, 20, 10, or 5 degrees) and for a given wavelength range (e.g., 400 nm to 700 nm, or 425 nm to 675 nm, or 450 nm to 650 nm), the reflective polarizer has an average light reflectance of at least 60 percent in a first polarization state 141 and an average light transmittance of at least 60 percent in an orthogonal second polarization state 142. The average light reflectance in the first polarization state 141 can be, for example, at least 70, 80, or 90 percent. The average light transmittance in the second polarization state 142 can be, for example, at least 70, 80, or 85 percent. In some embodiments, the optical film 150, 150' is a mirror film. In some embodiments, for substantially normally incident light 140 and for a given wavelength range, the mirror film has an average light reflectance of at least 60, 70, 80, or 90 percent in each of the orthogonal first and second polarization states 141 and 142. In some embodiments, the optical film 150, 150' is a partial reflector having an average light reflectance in the range of 20-80 percent, or 30-70 percent, or 40-60 percent in each of the orthogonal first and second polarization states 141 and 142 for substantially normally incident light 140 and for a given wavelength range.

[0027] FIG. 3 is a schematic cross-sectional view of an optical lens 200 according to some embodiments. The optical lens 200 includes a lens substrate 220 and any optical film 250 described herein (e.g., corresponding to optical film 150 or 150′) disposed on and substantially conforming to a major surface 221 of the lens substrate 220. An olefin layer 28 and / or an ethylene copolymer layer may face the lens substrate 220 (see, for example, the xyz coordinate system shown generally in FIGS. 1-3). In some embodiments, the lens substrate 220 includes an olefin composition. The olefin composition may be or include a cyclic olefin polymer (COP), a cyclic olefin copolymer (COP), or a blend thereof. In some such embodiments, or in other embodiments, the olefin layer 28 bonds the optical film 250 to the lens substrate 220.

[0028] 4 is a schematic diagram of a method for making an optical lens, according to some embodiments. The method includes providing an integrally formed optical film 250, which can be as described for optical film 150, 150' elsewhere herein. For example, optical film 250 can include a plurality of alternating first and second polymer layers 21 and 22 (20) disposed on a first protective layer 24, an olefin layer 28 disposed on the first protective layer 24 on the opposite side of the plurality of alternating first and second polymer layers 21 and 22, and a tie layer 26 disposed between and bonding the olefin layer 28 and the first protective layer 24 to each other. The method includes forming a lens substrate 220 on the optical film 250 such that the lens substrate 220 faces the olefin layer 28 and bonds it to the olefin layer 28. The lens substrate can include an olefin composition. The olefin layer can include a cyclic olefin copolymer, a cyclic olefin polymer, or a blend thereof. Providing an integrally formed optical film can include co-extruding and co-stretching all layers of the optical film. Molding the lens substrate 220 onto the optical film 250 can include an insert molding process, which, in brief, is placed adjacent to a surface of an upper mold section 460 and a resin 483 (e.g., a molten olefin composition) is injected (e.g., through a gate 465) into a cavity between the optical film 250 and a lower mold section 470. Further details regarding the insert molding process are described, for example, in U.S. Patent Application Publication No. 2021 / 0208320 (Ambur et al.) and U.S. Patent No. 11,065,855 (Klun et al.). EXAMPLES

[0029] All parts and percentages in the examples are by weight unless otherwise indicated. Reagents and solvents are available from MILLIPORE-SIGMA (Burlington, Mass.) unless otherwise indicated.

[0030] [Table 1]

[0031] For some film samples, two sets of films with layer structure ABCBA were made by coextrusion followed by costretching. These films showed that if the A layers are made from olefins and the C layers are made from polyesters commonly used in multilayer optical films, a coextrudable / costretchable material can be selected for the B layers. For example, a film with structure ABC'DCDCDC.... can be similarly made, where C' is a protective layer (e.g., a protective boundary layer) and the alternating D and C layers are adapted to reflect light primarily by optical interference.

[0032] The first film set with ABCBA structure was made by the following procedure. The outer (A) layers were made by extruding the resin through a 27mm TSE (twin screw extruder) through a neck tube and gear pump to a 5-layer feedblock and die. The melt train used a progressive temperature profile with a peak temperature of 270°C. The tie (B) layers were made by extruding the resin through a 27mm TSE with a progressive temperature profile peaking around 260°C through a neck tube and gear pump to a 5-layer feedblock. The core (C) layers were made by extruding the resins identified above through a 27mm TSE with a progressive temperature profile peaking around 270°C through a neck tube and gear pump to a 5-layer feedblock. The casting wheel was run at 50°C-70°C while the feedblock / die was held at a target temperature of 270°C. The film materials were as shown in the table below. The feed rate for each TSE was 10 lbs / hr, except for the C layer of Sample 10, which used a feed rate of 14.4 lbs / hr. For blends, parts by weight are given in parentheses.

[0033] [Table 2]

[0034] Various film samples were oriented and annealed in a biaxial KARO IV stretching lab machine (available from Bruckner Maschinenbau Siegsdorf, Germany). The procedure is as follows: The cast web film was transported to an oven at various temperatures, held for 60 seconds, and then stretched at several different ratios, as shown in the table below (the oriented regions of the film are xxxx longer than the initial film in each direction for a given stretch ratio of xxxx). The films were then removed from the KARO and evaluated. The transmission haze was measured using a haze-gard i haze meter available from BYK Instruments.

[0035] The percent transmission haze of the film samples stretched at a stretch ratio of 1×5 is reported in the table below.

[0036] [Table 3]

[0037] The percent transmission haze of the film samples stretched at a stretch ratio of 1×5.5 is reported in the table below.

[0038] [Table 4]

[0039] The percent transmission haze of the film samples stretched at a stretch ratio of 1×6 is reported in the table below.

[0040] [Table 5]

[0041] The percent transmission haze of film samples stretched to the indicated stretch ratios and annealed at 215° C. for 15 seconds is reported in the table below.

[0042] [Table 6]

[0043] The percent transmission haze of the unannealed film samples and the corresponding samples annealed at 215° C. for 15 seconds are reported in the table below.

[0044] [Table 7]

[0045] The percent transmission haze of the biaxially stretched film samples at the indicated stretch ratios is reported in the table below.

[0046] [Table 8]

[0047] The percent transmission haze of film samples biaxially stretched to the indicated stretch ratios and annealed at 215° C. for 15 seconds is reported in the table below.

[0048] [Table 9]

[0049] A second set of films having an ABCBA structure was made, for example, to determine the effect of the A layer composition on optical and bonding properties (e.g., the effect of the glass transition temperature of the COC blend). Film samples were made as generally described above using the resins shown in the table below. The feed rate of each TSE was 10 lbs / hr for each sample.

[0050] [Table 10]

[0051] The glass transition temperature (Tg) of the A layer was obtained using a Differential Scanning Calorimeter (DSC). The DSC used a heat / cool / heat cycle. Each sample was weighed and placed into the DSC. The following method was used. Method log: 1: Data storage: Off 2: Equilibrate at -70.00℃ 3: Isothermal for 5.00 min 4: Data storage: On 5: Heat up to 200.00℃ at 20.00℃ / min 6: Marks the end of cycle 1 7: Data storage: Off 8: Equilibrate at 200.00℃ 9: Isothermal for 5.00 min 10: Data storage: On 11: Decrease temperature to -70.00℃ at 20.00℃ / min 12: Marks the end of cycle 2 13: Data storage: Off 14: Equilibrate at -70.00℃ 15: Adjustment by + / - 1.00℃ every 60 seconds 16:5.00 min isothermal 17: Data storage: On 18: Heat up to 200.00℃ at 3.00℃ / min 19: Marks the end of cycle three. 20: Data storage: Off 21: End of method

[0052] The Tg was then measured at the inflection point of the hump in the second ramp cycle beginning at step 18, which one skilled in the art would recognize as the Tg. The resulting Tg's are reported in the table below.

[0053] [Table 11]

[0054] The film samples were uniaxially oriented in a biaxial KARO stretching lab apparatus. The procedure was as follows: the cast web film was transported to an oven at various temperatures, held for 60 seconds, and then stretched at several different ratios. The films were then removed from the KARO and evaluated for haze as described above. The resulting transmission haze (%) for various stretch ratios and oven temperatures is shown in the table below.

[0055] [Table 12]

[0056] [Table 13]

[0057] The peel force was then measured on various cast film samples using an IMASS SP-2100 with a 10 lb load cell. The films were cut into 1 inch wide samples and laminated to glass with double sided tape. The glass was loaded into an IMASS holder and the 90 degree peel was measured. The pull speed was set at 12 in / min with a 2 second delay and the force averaged for 5 seconds. This was repeated 4 times. The average was taken and reported. The table below reports the peel force data for these films. Many of the films exhibited non-delamination peel forces or peel forces high enough that separation of the film stack would not occur in the end application.

[0058] [Table 14]

[0059] Terms such as "about" will be understood by those of skill in the art in the context in which they are used and described herein. Unless otherwise clear to one of skill in the art in the context in which they are used and described herein, the use of "about" as applied to quantities expressing feature sizes, amounts, and physical properties will be understood to mean within 10 percent of a particular value. An amount given as about a particular value may be exactly that particular value. For example, unless otherwise clear to one of skill in the art in the context in which they are used and described herein, an amount having a value of about 1 means that the amount has a value between 0.9 and 1.1, and may even be 1.

[0060] Terms such as "substantially" will be understood by those of ordinary skill in the art in the context in which they are used and described in this description. If the use of "substantially" with respect to a property or characteristic is not clear to one of ordinary skill in the art in the context in which it is used and described in this description, and if it is clear to one of ordinary skill in the art what is meant by the opposite of that property or characteristic, then the term "substantially" will be understood to mean that the property or characteristic is exhibited to a greater extent than the opposite of that property or characteristic is exhibited.

[0061] All references, patents, or patent applications referenced above are hereby incorporated by reference in their entirety. In the event of any inconsistency or contradiction between any of the incorporated references and this application, the information in the foregoing description shall prevail.

[0062] Descriptions of elements in the drawings should be understood to apply equally to corresponding elements in other drawings unless otherwise indicated. Although specific embodiments have been illustrated and described herein, those skilled in the art will appreciate that the specific embodiments illustrated and described may be replaced by various alternative and / or equivalent implementations without departing from the scope of the present disclosure. The present application is intended to cover any adaptations, or variations, or combinations of the specific embodiments discussed herein. Accordingly, the present disclosure is intended to be limited only by the claims and the equivalents thereof.

Claims

1. An optical film, a plurality of alternating first and second polymer layers disposed on a first protective layer, wherein each of the first and second polymer layers has an average thickness of less than about 500 nm, and the first protective layer has an average thickness of more than about 750 nm; an olefin layer disposed on the first protective layer opposite the plurality of alternating first and second polymer layers, the olefin layer comprising a cyclic olefin copolymer, a cyclic olefin polymer, or a blend thereof, the olefin layer comprising an unstructured major surface opposite the first protective layer; and a tie layer disposed between and bonding the olefin layer and the first protective layer together; the optical film is integrally formed and has an average interlayer peel force of greater than about 500 g / inch, each layer of the optical film is formed from a thermoplastic polymer, the thermoplastic polymer having a melt flow index greater than 5 g / 10 min and an intrinsic viscosity in the range of 0.3 dl / g to 1.2 dl / g as measured in a solvent blend comprising 60 weight percent o-chlorobenzene and 40 weight percent phenol.

2. 10. The optical film of claim 1, wherein the unstructured major surface has an average peak-to-valley (PV) surface roughness Rz of less than about 1 micrometer.

3. The optical film of claim 1 having a transmission haze of less than about 5 percent.

4. The optical film of claim 1 , wherein the composition of the tie layer is different from the composition of each of the first protective layer and the first and second polymer layers.

5. The optical film of claim 1 , wherein the tie layer comprises an ethylene copolymer.

6. 10. The optical film of claim 1, wherein the tie layer has a glass transition temperature of less than about -100.degree. C. and a melting point of greater than about 100.degree.

7. An optical film, a plurality of alternating first and second polymer layers disposed on a first protective layer, wherein each of the first and second polymer layers has an average thickness of less than about 500 nm, and the first protective layer has an average thickness of more than about 750 nm; an olefin layer disposed on the first protective layer opposite the plurality of alternating first and second polymer layers, the olefin layer comprising a cyclic olefin copolymer, a cyclic olefin polymer, or a blend thereof; and a tie layer disposed between and bonding the olefin layer and the first protective layer, the tie layer having a composition different from the compositions of the first protective layer and the first and second polymer layers, the optical film is integrally formed and has an average interlayer peel force of greater than about 500 g / inch, each layer of the optical film is formed from a thermoplastic polymer, the thermoplastic polymer having a melt flow index greater than 5 g / 10 min and an intrinsic viscosity in the range of 0.3 dl / g to 1.2 dl / g as measured in a solvent blend comprising 60 weight percent o-chlorobenzene and 40 weight percent phenol.

8. The optical film of claim 7, wherein the bonding layer is an ethylene copolymer layer.

9. 9. The optical film of claim 8, wherein the ethylene copolymer layer comprises an ethylene copolymer containing one or more of styrene, acrylic, vinyl, or maleic anhydride groups.

10. 10. An optical lens comprising: a lens substrate; and the optical film according to any one of claims 1 to 9, disposed on and substantially conforming to a major surface of the lens substrate, wherein the olefin layer faces the lens substrate.

11. 10. The optical film according to claim 1, wherein the number of the plurality of alternating first and second polymer layers is at least 10 in total.

12. The optical film according to any one of claims 1 to 9, wherein the optical film is a reflective polarizer or a mirror film.

13. 1. A method of manufacturing an optical lens, comprising: An integrally formed optical film, a plurality of alternating first and second polymer layers disposed on a first protective layer, wherein each of the first and second polymer layers has an average thickness of less than about 500 nm, and the first protective layer has an average thickness of more than about 750 nm; an olefin layer disposed on the first protective layer opposite the plurality of alternating first and second polymer layers, the olefin layer comprising a cyclic olefin copolymer, a cyclic olefin polymer, or a blend thereof; and a tie layer disposed between and bonding the olefin layer and the first protective layer together; wherein the optical film has an average interlayer peel force of greater than about 500 g / inch, and each layer of the optical film is formed from a thermoplastic polymer, the thermoplastic polymer having a melt flow index greater than 5 g / 10 min and an intrinsic viscosity in the range of 0.3 dL / g to 1.2 dL / g as measured in a solvent blend comprising 60 weight percent o-chlorobenzene and 40 weight percent phenol; molding a lens substrate onto the optical film such that the lens substrate faces and bonds to the olefin layer, the lens substrate comprising an olefin composition; A method comprising:

14. The method of claim 13 , wherein providing the integrally formed optical film comprises co-extruding and co-stretching all layers of the optical film.

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