CN113039468B - Polarizing optical functional film laminate and polarizing film used therefor - Google Patents

Abstract

The present invention relates to a polarizing optical function film laminate capable of improving the protection function of a cut end face of a polarizing film in a high-temperature and high-humidity environment and improving the reliability of the polarizing film, and a polarizing film used for the polarizing optical function film laminate. The polarizing optical function film laminate has at least a polarizing film including a polarizer and a protective film laminated on at least one side of the polarizer, and has a given shape formed by cut end faces, wherein a clad layer including a component of a resin material not included in the polarizing optical function film laminate as a 1 st resin component is formed on at least the cut end face of the polarizer among the cut end faces.

Description

Polarizing optical functional film laminate and polarizing film used therefor

Technical Field

The present invention relates to a polarizing optical function film laminate, and more particularly, to a polarizing optical function film laminate in which a coating layer is formed on a cut end surface of a polarizer included in the polarizing optical function film laminate, and a polarizing film used for the polarizing optical function film laminate.

Background

In recent years, polarizing optical functional film laminates or polarizing films that are a part thereof have been used in a wide variety of image display devices such as automobile instrument displays, smart watches, head-mounted displays (microphones), smart phones, notebook computers, tablet computers (tablets), and display screens (monitors). In addition, from the viewpoint of design, it is required for these image display devices to be processed into various shapes such as a curved shape, a slit shape, or a shape having a hole, which are not limited to a rectangular shape, and in order to satisfy such a requirement, there have been proposed methods such as punching using a tool type represented by thomson blades (thomson blades) and sharp-pointed blades (pinacle blades), end face processing using a full back cutter and an end mill, and laser cutting using a laser (for example, see patent document 1).

Further, recently, in order to maximize the display portion of the image display device, a design of narrowing the width of the frame portion has become mainstream, and the quality requirement and the dimensional accuracy requirement of the cut end portion of the polarizing film cut into a desired shape have become stricter.

On the other hand, the image display device having the polarizing film mounted thereon as described above is used in various applications, and therefore, is often used for a long time in a high-temperature and high-humidity environment or the like, and in such an environment, a phenomenon in which moisture enters and exits from a cut end surface of the polarizing film to which a heat load is applied occurs. Generally, a polarizing plate shows polarization performance by impregnating an stretched film made of a resin material of a PVA matrix with iodine to form a PVA-polyiodide complex, but when the cut end faces of such a PVA-iodine polarizing plate are exposed to a high-temperature and high-humidity environment, the cut end faces are affected by moisture entering and exiting from the cut end faces, and problems regarding quality such as the following are caused: the PVA-polyiodide complex in the PVA film is denatured, and leaks (decolors) to the outside with fluidity, resulting in impairment of the polarizing function of the end portion. Hereinafter, this phenomenon will be referred to as "depolarization" in the present specification.

In order to solve the above problems, a method of coating the outer peripheral cut surface of a polarizing film cut into a desired shape with a resin coating has been proposed (patent document 2), but in the method proposed in this patent document 2, in order to form a coating film, a solution in which a resin is dissolved in a solvent needs to be applied to the cut surface of the polarizing film by a roll coater or the like and dried, which causes another problem that the manufacturing process becomes long and complicated, leading to an increase in manufacturing cost. Patent document 3 proposes forming protective layers arranged on both front and back surfaces of a polarizer so as to be larger than the polarizer, thereby providing a groove-like gap between the protective layers, and filling the gap with a sheet, but the method of this proposal also causes a long and complicated manufacturing process, as in the case of patent document 2. Further, when a film is formed on a cut end face of a polarizing film cut into a non-linear shape having a curved outer periphery by using a general-purpose coating mechanism such as a roll coater or a slit coater, it is necessary to maintain a uniform gap between a liquid discharge unit of a coater and the cut end face of the polarizing film. In this method, a solution obtained by dissolving a resin material in an organic solvent is used as the coating liquid, and in this case, the coating liquid may penetrate into the interlayer of the polarizing film having a multilayer structure, which may cause a problem that the interlayer adhesion is lowered by the coating liquid penetrating into the interlayer. In addition, in this method, there is a concern that the constituent substrate of the polarizing film may be corroded due to the organic solvent for dilution contained in the coating liquid. In order to avoid this problem, it is conceivable to spray a solvent-free UV curable resin, but in this case, the material for forming the film is limited, and the viscosity is higher than that of the diluent, so that the film formation becomes difficult, and the thickness of the film is set to such a degree that the dimensional accuracy of the product cut into a non-linear shape is not affected.

There are also droplet coating methods along the cut shape such as ink jet printing and dispensing methods, but it is also difficult to achieve a thinner film by this method, and the problem of contamination of the surface layer of the polarizing film with droplets caused by film formation is caused, and therefore it is technically difficult to apply this method.

In addition, the optical film generally has a surface protective film and a release liner on one side or both sides thereof which are peeled off when the optical film is attached to a device, but when the film disclosed in patent document 2 is formed on the cut end portion of the optical film configured in this manner, the film is formed on the cut end surfaces of the surface protective film and the release liner at the same time, and thus the cut end surfaces of the surface protective film and the release liner and the cut end surface of the optical film are fixed to each other by the film covering the cut end portion, which makes it difficult to peel the surface protective film and the release liner. Further, when the surface protective film and the release liner are peeled off, the coating film formed at the cut end portion may be peeled off from the optical film. Further, a part of the coating film which causes peeling becomes a cause of contamination by foreign matters in the production process.

Vapor Deposition, CVD (Chemical Vapor Deposition), and other so-called vacuum dry coating methods are also conceivable, but Vapor Deposition is mainly aimed at forming a film of a metal component, and it is difficult in principle to form an organic film, while CVD is a method capable of forming a film by enclosing an organic monomer in a reaction furnace and performing plasma CVD or the like, but it takes too long to form a film having a thickness of 100nm or more, and therefore productivity is low, and it is difficult to apply the method in reality.

In addition, the following methods are proposed: the reliability of the cut end face is improved by melting a protective film, which is one of the components of the polarizing film, by a cutting method using a laser beam having an infrared wavelength, and forming a clad layer covering the cut end face of the polarizer from the molten film (patent document 4). This document teaches: the protective film made of a material having originally low moisture permeability can be melted by heat at the time of cutting, and the polarizer end face after laser cutting processing can be coated with the melt. Patent document 4 describes that this method can improve the reliability of the processed end of the polarizing film in a high-temperature and high-humidity environment. In addition, since the cladding layer can be formed simultaneously with the laser cutting process by this method, the outer periphery coating step after the shape processing can be omitted.

Further, the following method is also proposed: in the laser dicing process, an optical laminate roll is prepared in which a long optical laminate composed of a long optical film and protective sheets laminated on both surfaces of the optical film is wound into a roll, and the optical laminate is subjected to a laser dicing process while being continuously paid out from the roll (patent document 5). According to the teaching of patent document 5, protective sheets positioned on the lower side among protective sheets laminated on both sides of the optical film can be made to function as a carrier base material. It is understood that, in this case, as for the protective sheet on the lower side, half-cutting based on laser irradiation may be performed.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2018-22140

Patent document 2: japanese laid-open patent publication No. 8-146219

Patent document 3 Japanese examined patent publication No. 7-34415

Patent document 4: japanese patent No. 5558026

Patent document 5: japanese patent laid-open publication No. 2017-207585

Disclosure of Invention

Problems to be solved by the invention

However, even with the method taught in patent document 4, it is difficult to impart a sufficient protective function to the cut end face of the polarizer with a coating film formed only from a melt of a protective film provided on one surface of the polarizer. The reason for this is that polarizing films are formed with various thicknesses of polarizers and protective films, and it is not possible to ensure that the volume of the melt from the protective film provided on one surface of the polarizer is sufficient to form a film having a thickness sufficient to prevent the permeation of water from the cut end surface, at a width sufficient to cover the cut surface of the polarizer over the entire thickness of the polarizer.

Patent document 4 teaches forming the protective film of the polarizer by using a given resin material with low moisture permeability, but even when such a material is used, it is not possible to ensure that the amount of melt from the protective film generated at the laser cutting of the polarizing film is sufficient to form a film covering the cut end face of the polarizer, and it is difficult to form a film having a thickness capable of sufficiently preventing moisture from penetrating from the cut end face.

As described above, with the above methods proposed in the related art, a polarizing film that can satisfy the strict quality requirements for "depolarization" caused by color leakage from the end face cut from the polarizer in recent years has not yet been obtained.

Means for solving the problems

The present inventors have recognized the above-described problems in the prior art and have conducted intensive studies to solve the problems, and as a result, have found the following phenomenon that can be used to form a film that can suppress the permeation of moisture at the cut end face of a polarizing film: in a polarizing optical function film laminate having a polarizing film in which a protective film is laminated on at least one side of a polarizer, a sheet made of a resin material separately from the polarizing optical function film laminate is arranged on one surface of the polarizing optical function film laminate in a superimposed manner, and laser light is irradiated from the other surface of the polarizing optical function film laminate on the opposite side to the sheet in the thickness direction of the polarizing optical function film laminate, and laser cutting processing is performed in which the irradiation position of the laser light is moved along a predetermined shape in the plane of the laminate, whereby the polarizing optical function film laminate is cut into a predetermined shape, and under the irradiation of the laser light, a sheet component present in a part in the thickness direction is scattered as a mist by laser energy, and at least a part of the mist of the sheet component is deposited on a laser-cut end face formed on the polarizer of the polarizing optical function film laminate, whereby a coating layer containing at least the component of the sheet is formed so as to cover the laser-cut end face of the polarizer. The film thus formed can improve the function of protecting the cut end face of the polarizing film in a high-temperature and high-humidity environment, and improve the reliability of the polarizing film.

The present invention utilizes the above-described phenomenon to provide a polarizing optical function film laminate in which a coating layer is formed on a cut end surface of a polarizer included in the polarizing optical function film laminate, and a polarizing film used for the polarizing optical function film laminate.

A polarizing optical function film laminate according to one embodiment of the present invention has at least a polarizing film including a polarizer and a protective film laminated on at least one side of the polarizer, and has a predetermined shape formed by cut end faces, wherein a clad layer including a component of a resin material not included in the polarizing optical function film laminate as a 1 st resin component is formed on at least the cut end face of the polarizer among the cut end faces.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a polarizing optical function film laminate in which the problems concerning cut end faces existing in the above-described prior art are improved, and a polarizing film used for the polarizing optical function film laminate.

Drawings

Fig. 1 is a schematic cross-sectional view showing an example of a polarizing optical functional film laminate according to an embodiment of the present invention in a state before dicing.

Fig. 2 is a schematic cross-sectional view showing an example of a state in which the polarizing optical function film laminate of fig. 1 is cut into a desired shape by laser irradiation.

Fig. 3 is a schematic view of a cross section of the laminated body, showing a state of the laminated body with sheets in the dicing process by laser irradiation.

Fig. 4A is an optical microscope image showing depolarization observed under transmission illumination of crossed nicols with respect to a cut end surface in a direction perpendicular to the light absorption axis of the polarizer, and shows an example in which depolarization due to color leakage does not occur.

Fig. 4B is an optical microscope image showing depolarization observed under transmission illumination of crossed nicols with respect to a cut end surface in a direction perpendicular to the light absorption axis of the polarizer, and shows an example in which depolarization due to color leakage occurs.

Fig. 5 is a view showing an example of an SEM image of a cut cross section of the laminate with sheets of the present invention after laser dicing.

Fig. 6A is a diagram showing an example of the depolarization length achieved by using the laminated body with sheets according to the embodiment of the present invention.

Fig. 6B is a diagram showing an example of the depolarization length achieved by using a conventional end mill.

Fig. 7 is a cross-sectional SEM image of the vicinity of the polarizing film of the sheet-attached laminate of the embodiment of the present invention after the laser cutting process.

Fig. 8 is an EDX (energy dispersive X-ray analysis) image of the same site as fig. 7.

Fig. 9 is a sectional SEM image showing a cut end of the polarizer in an enlarged manner in the image shown in fig. 7.

Fig. 10 is an EDX image of the same portion as fig. 9.

Fig. 11 is a schematic view of a laser beam shaping apparatus for performing laser dicing on a long strip-shaped polarizing optical functional film laminate in a roll-to-roll manner.

Fig. 12A is a plan view showing an example of a cutting processing layout when a product cut into a smartphone shape is manufactured from a large polarizing film, and showing the whole thereof.

Fig. 12B is a plan view showing an example of a cutting layout when a product cut into a smartphone shape is manufactured from a large polarizing film, and showing a part thereof in an enlarged manner.

Fig. 13A is a plan view showing an example of a cutting processing layout when a product cut into an automobile instrument panel shape is manufactured from a large polarizing film, and showing the whole thereof.

Fig. 13B is a plan view showing an example of a layout of a cutting process when a product cut into an automobile instrument panel shape is manufactured from a large polarizing film, and showing a part thereof in an enlarged manner.

Fig. 14 is a plurality of photographs showing an example of a polarizing film cut into a shape of a smartphone in parallel.

Fig. 15A is an SEM image of example 1, in which a cut section is observed from the molecular orientation direction.

Fig. 15B is an SEM image of example 2, in which the cut section was observed from the molecular orientation direction.

Fig. 15C is an SEM image of comparative example 1, which is obtained by observing a cut section from the molecular orientation direction.

Fig. 15D is an SEM image of comparative example 2, which is obtained by observing a cut section from the molecular orientation direction.

FIG. 16 is an image showing the analysis result by TOF-SIMS of example 1.

Fig. 17 is an optical microscope image showing laser processed grooves formed in the sheet peeled after the laser cutting process.

Fig. 18 is a graph showing the results of elemental analysis of the clad layer formed on the cut end face in example 1.

FIG. 19 is an image showing the analysis result by TOF-SIMS of example 6.

FIG. 20 is an image showing the analysis result by TOF-SIMS of example 7.

FIG. 21 is a graph showing the analysis result by TOF-SIMS of comparative example 4.

FIG. 22 is a graph showing the analysis result by TOF-SIMS of comparative example 5.

FIG. 23 is an image showing the analysis result by TOF-SIMS of reference example 1.

FIG. 24 is an image showing the analysis result by TOF-SIMS of reference example 2.

Detailed Description

The present invention will be described in more detail with reference to embodiments below, but the present invention is not limited to these embodiments.

(polarizing optical functional film laminate)

Fig. 1 is a schematic cross-sectional view showing an example of a polarizing optical functional film laminate according to an embodiment of the present invention in a state before dicing processing is performed, more specifically, in a state before a clad layer covering a cut end face of a polarizer is formed. The polarizing optical functional film laminate 1 includes at least a polarizing film 12, and may further include a surface treatment layer 13, a surface protection film 14, and a contamination prevention film 23 as optional elements, but is not limited to these elements.

The polarizing optical function film laminate 1 may further have a release liner 16 bonded thereto via a pressure-sensitive adhesive layer 15. Hereinafter, a polarizing optical functional film laminate provided with a pressure-sensitive adhesive layer 15 and a release liner 16 is represented by the reference numeral "1A", and this polarizing optical functional film laminate 1A will be described as an example.

Normally, the polarizing film 12 is mainly composed of a polarizer 10 and a protective film 11 laminated on one or both principal surfaces of the polarizer 10 as shown in fig. 1, but other optical functional films exhibiting an optical function such as a retardation film, a brightness enhancement film, and a viewing angle compensation film may be further laminated. In such a case, a laminate including these optical functional films constitutes polarizing film 12. In addition, although fig. 1 shows an example in which the protective films 11a and 11b are laminated on the main surfaces on both sides of the polarizer 10, the protective film 11 may be laminated on only one main surface.

The polarizer 10 may be made of a resin film. As the resin film, any appropriate resin can be used, but a polyvinyl alcohol resin (hereinafter referred to as a PVA-based resin) is generally used. Examples of the PVA-based resin include: polyvinyl alcohol, ethylene-vinyl alcohol copolymer. The ethylene-vinyl alcohol copolymer can be obtained by saponifying an ethylene-vinyl acetate copolymer. The saponification degree of the PVA-based resin is usually 85 mol% to 100 mol%, preferably 95.0 mol% or more, more preferably 99.0 mol% or more, and particularly preferably 99.93 mol% or more. The degree of saponification can be determined in accordance with JIS K6726-1994. By using the PVA-based resin having such a saponification degree, the polarizer 10 having excellent durability can be obtained.

The PVA-based resin constituting the polarizer 10 can be used as a polarizer after various treatments such as swelling treatment, stretching treatment, dyeing treatment with a dichroic substance, typically iodine, crosslinking treatment, washing treatment, and drying treatment are performed by a conventional method. The number of times, order, time, and the like of each process can be set as appropriate. The PVA type resin may be formed into a film as a coating layer on a separate substrate, and the film may be subjected to the above-mentioned respective treatments. The stretching direction in the stretching treatment corresponds to the absorption axis direction of the polarizer obtained. From the viewpoint of obtaining excellent polarization characteristics, the PVA-based resin is usually uniaxially stretched 3 to 7 times.

As the PVA-based resin film, a resin film formed by any method such as a casting method, an extrusion method, or the like, in which a dope dissolved in water or an organic solvent is cast into a film, can be suitably used.

The average polymerization degree of the PVA-based resin may be appropriately selected depending on the purpose. The average polymerization degree is usually 1000 to 10000, preferably 1200 to 6000, and more preferably 2000 to 5000. The average polymerization degree can be determined in accordance with JIS K6726-1994.

Typically, the resin film constituting the polarizer 10 is impregnated with a dichroic material. Examples of the dichroic substance include: iodine, organic dyes, and the like. These may be used alone or in combination of two or more. As the dichroic substance, iodine can be preferably used.

As the organic dye, for example: red BR, red LR, red R, pink LB, red jade BL, boldo GS, sky Blue LG, lemon yellow, blue BR, blue 2R, navy Blue RY, green LG, purple LB, purple B, black H, black B, black GSP, yellow 3G, yellow R, orange LR, orange 3R, scarlet GL, scarlet KGL, congo red, brilliant purple BK, sultap Blue (Supra Blue) G, sultap Blue GL, sultap Orange (Supra Orange) GL, direct sky Blue, direct classical Orange S (Direct First Orange S), classical Black (First Black), and the like. These dichroic substances may be used alone or in combination of two or more.

The thickness of the polarizer 10 can be set to any appropriate value. The thickness of the polarizer which has been put into practical use is 5 μm to 30 μm.

The polarizer 10 preferably exhibits dichromatic absorption characteristics in a wavelength range of 380nm to 780 nm. The polarizer 10 generally has a monomer transmittance (Ts) of 43% or more. The theoretical upper limit of the monomer transmittance is 50%, and the practical upper limit is 46%. The monomer transmittance (Ts) is a Y value obtained by measuring and correcting the luminosity with a 2-degree field of view (C light source) according to JIS Z8701, and can be measured, for example, with a spectrophotometer (V7100, manufactured by japan). The degree of polarization of the polarizer 10 is usually 99.9% or more.

Examples of the material for forming the protective films 11a and 11b include: cellulose resins such as cellulose diacetate and cellulose Triacetate (TAC), (meth) acrylic resins, cycloolefin resins, olefin resins such as polypropylene, ester resins such as polyethylene terephthalate resins, polyamide resins, polycarbonate resins, and copolymer resins thereof. The term "(meth) acrylic resin" means an acrylic resin and/or a methacrylic resin.

The thickness of the protective films 11a and 11b can be selected to be any value within the range of 10 to 200 μm.

The materials, thicknesses, and the like may be the same or different between the protective films 11a and 11b.

Typically, the protective films 11a and 11b are laminated on the main surfaces of the polarizer 10 via adhesive layers (not shown). As the adhesive constituting the adhesive layer, any appropriate adhesive can be used. For example, an aqueous adhesive, a solvent adhesive, an active energy ray-curable adhesive, or the like can be used. As the aqueous adhesive, an adhesive containing a PVA-based resin is preferably used.

The protective films 11a and 11b may contain one or more kinds of any appropriate additives. Examples of additives include: ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, colorants, and the like.

The surface treatment layer 13 may be formed by hard coating, antireflection, or diffusion or antiglare treatment on the surface of each of the protective films 11a and 11b opposite to the polarizer 10. In the embodiment shown in fig. 1, the surface treatment layer 13 is formed only on the protective film 11a laminated on one principal surface of the polarizer 10.

The surface protection film 14 is laminated on the protection film 11 via the surface treatment layer 13 when the surface treatment layer 13 is formed, and is laminated on the protection film 11 when the surface treatment layer 13 is not formed. The surface protection film 14 is a member that is bonded to the protection film 11a in a peelable manner for the purpose of protecting the protection film 11a from damage due to contact or adhesion of foreign substances, and is composed of an adhesive layer 14a and a resin film 14 b.

The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 14a may be made of any polymer material selected from acrylic, rubber, urethane, silicone and polyester, and the thickness thereof may be appropriately selected from the range of 1 to 100 μm.

The resin film 14b may be an acrylic resin, an olefin resin such as polyethylene or polypropylene, or an ester resin such as polyethylene terephthalate, and preferably has a thickness in the range of 5 to 100 μm.

The surface protective film 14 is to be peeled off when the polarizing film is mounted on an optical display device or the like. Therefore, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 14a is preferably light in adhesive force, and preferably 5N/20mm or less in peel force.

The release liner 16 is laminated on the surface of the polarizing film 12 opposite to the surface protection film 14, that is, the surface of the protection film 11b opposite to the polarizer 10, with the adhesive layer 15 interposed therebetween. The main surface of the release liner 16 in contact with the pressure-sensitive adhesive layer 15 is subjected to a mold release treatment in order to obtain good releasability. Release liner 16 is coated with adhesive layer 15 at a point in time until polarizing film 12 is bonded to the optical display panel. When polarizing film 12 is bonded to the optical display panel, release liner 16 is peeled from protective film 11b with adhesive layer 15 remaining on the polarizing film 12 side, and polarizing film 12 is bonded to the optical display panel via adhesive layer 15. In view of workability, the peel force of the release liner 16 with respect to the pressure-sensitive adhesive layer 15 is preferably 5N/20mm or less.

The release liner 16 is preferably made of a resin film, and for example, an olefin resin such as polyethylene and polypropylene, or an ester resin such as polyethylene terephthalate may be used, but the resin is not limited thereto. The thickness of the release liner 16 may be appropriately selected within a range of 1 μm to 100 μm. In addition, release liner 16Preferably, the material is formed of a material having a low moisture permeability, and the value of the moisture permeability of the material of the release liner 16 is preferably 200g/m in a gas atmosphere of 40 ℃ and 90% RH ² 24h or less, more preferably 150g/m ² 24h or less.

As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 15, a pressure-sensitive adhesive containing any polymer material of acrylic, rubber, urethane, silicone, olefin, and polyester as a main component can be used. From the viewpoint of cost reduction, acrylic or rubber-based adhesives are preferred. The thickness of the pressure-sensitive adhesive layer 15 may be appropriately set within a range of 1 μm to 50 μm.

The surface protection film 14 may be provided with a contamination prevention film 23. The contamination prevention film 23 includes at least a resin film substrate 23a made of a resin material, and further includes a pressure-sensitive adhesive layer 23b disposed on one surface of the resin film substrate 23 a. The resin film base 23a is laminated on the surface protection film 14 via the adhesive layer 23b.

As the resin film 23a, a conventional resin film can be used, and for example, an acrylic resin, an olefin resin such as polyethylene and polypropylene, an ester resin such as polyethylene terephthalate resin, or the like can be used. The resin film 23a preferably has a thickness in the range of 20 μm to 100 μm.

On the other hand, as the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 23b, a material containing any of acrylic, rubber, urethane, silicone and polyester as a main component can be used, and the thickness of the pressure-sensitive adhesive layer 23b can be appropriately selected within a range of 1 to 100 μm.

The contamination prevention film 23 is peeled off after the laser dicing process. Therefore, the adhesive constituting the adhesive layer 23b is preferably an adhesive having a light adhesive force to the surface protective film 14, and the adhesive force thereof is preferably equal to or smaller than the adhesive force of the surface protective film 14 used. If the adhesive force of the pressure-sensitive adhesive is larger than the adhesive force of the surface protective film 14, the surface protective film 14 may be peeled off when the contamination countermeasure film 23 is peeled off, which is not preferable.

The polarizing optical function film laminate 1A is cut into a desired shape by laser cutting before the polarizing film 12 is bonded to the optical display panel via the adhesive layer 15. The following hidden troubles exist: the melt, particles, and the like generated during the laser cutting process are scattered as droplets, and the scattered components contaminate the surface layer on the main surface of the polarizing film on the laser light incident surface side. By providing the contamination countermeasure film 23, the contamination can be prevented or suppressed.

In addition, when the contamination prevention film is provided in this way, burrs that may be generated on the cut end surfaces can be suppressed. Among the layers or films constituting the polarizing optical function film laminate 1A, the layer or film located on the outermost surface side as viewed in the laser irradiation direction, in the example of fig. 1, on the cut end surface of the resin film 14b constituting the surface protective film 14, a burr "a" may be generated in a state of protruding to the outside of the polarizing optical function film laminate 1A (see fig. 5), and by providing the contamination countermeasure film 23, such burr can be suppressed to 0 to 20 μm in the lamination direction of the polarizing optical function film laminate 1A. Thus, when a plurality of laminated bodies cut into predetermined same shapes are laminated and integrated after the cutting process, the increase of the stacking height due to the burr can be suppressed, and the transmission efficiency can be improved. The transmission efficiency is further improved by making the burr 10 μm or less, and the transmission efficiency is remarkably improved by making the burr 5 μm or less.

(laser cutting processing)

Fig. 2 shows an example of a state in which the polarizing optical function film laminate 1A of fig. 1 is cut into a desired shape by laser irradiation in the same manner as in fig. 1. By using a laser, not only the polarizing optical function film laminate 1A can be easily cut into a given shape, but also a clad layer can be formed on the cut end face of the polarizer 10 included in the polarizing optical function film laminate 1A along with the cutting process. During the cutting process, the sheet 17 is disposed so as to face the main surface of the polarizing film 12 opposite to the laser light entrance surface, and in the present embodiment, the sheet 17 is disposed so as to face the surface 16a of the polarizing optical functional film laminate 1A located outside the release liner 16. Hereinafter, the polarizing optical functional film laminate 1A on which the sheet 17 is disposed is referred to as a "laminate with sheets", and the whole is denoted by a symbol "2".

The sheet 17 includes at least a resin film substrate 17a made of a resin material, and further includes an adhesive layer 17b disposed on one surface of the resin film substrate 17 a. The resin film base 17a is bonded to the release liner 16 via the pressure-sensitive adhesive layer 17b so as to be peelable, and is peeled from the release liner 16 after the dicing process.

As the resin film constituting the resin film substrate 17a, a conventional resin film can be used, and for example, an acrylic resin, an olefin resin such as polyethylene and polypropylene, an ester resin such as polyethylene terephthalate resin, or the like can be used. The resin film substrate 17a preferably has a thickness in the range of 5 μm to 200 μm. The resin film base 17a is preferably formed of a material having a low moisture permeability, and the value of the moisture permeability of the material of the resin film base 17a is preferably 200g/m in a gas atmosphere having a temperature of 40 ℃ and a humidity of 90% RH ² 24h or less, more preferably 150g/m ² 24h or less.

On the other hand, the pressure-sensitive adhesive layer 17b is preferably formed of a polymer material mainly composed of any of acrylic, urethane, silicone, rubber, and polyester. The pressure-sensitive adhesive layer 17b is preferably formed of a pressure-sensitive adhesive having a light peeling adhesive force, and the peeling force of the pressure-sensitive adhesive layer 17b is preferably equal to or smaller than the peeling force of the release liner 16 of the polarizing optical function film laminate 1A. This is because, when the peeling force of the pressure-sensitive adhesive layer 17b of the sheet 17 is larger than the peeling force of the release liner 16, there is a possibility that the release liner 16 is peeled together when the sheet 17 is peeled after the laser dicing process. In general, when the sheet 17 is peeled off after the laser dicing process, the adhesive layer 17b is removed together with the resin film base material 17 a.

The laminated body with sheets 2 is irradiated with a laser beam in the thickness direction of the polarizing optical function film laminate 1A from the other surface of the polarizing optical function film laminate 1A on the opposite side to the sheet 17, and from the surface on the side of the contamination prevention film 23 in the illustrated embodiment. The "thickness direction" is not necessarily a direction perpendicular to the layers constituting the polarizing optical function film laminate 1A, as long as it is a direction penetrating the layers. The dicing process by the laser may be performed in a state where the polarizing optical function film laminate 1A is singulated into individual pieces, but from the viewpoint of efficient production, it is preferably performed in a state of a long strip film as described later. Therefore, the laminate 2 with sheets is preferably formed in advance in the form of a long strip film wound in a roll.

Fig. 3 shows a state of the laminated body 2 with sheets in the dicing process by laser irradiation in a schematic view of a cross section of the laminated body. By laser irradiation, the polarizing optical function film laminate 1A of the laminated body with sheet 2 is formed with a cut groove 2a over the entire thickness thereof including the release liner 16. Therefore, by moving the irradiation position of the laser light along a given shape in the plane of the polarizing optical function film laminate 1A, the polarizing optical function film laminate 1A can be cut into a desired shape. In the dicing, the polarizing optical function film laminate 1A constituting the laminate 2 with the sheet is completely cut in the thickness direction, and further cut to a depth where a part of the sheet remains. This is for forming a coating layer (particularly, the coating layer 18 b) described later sufficiently, for reusing the sheet as a carrier film, and for preventing displacement in consideration of workability in a subsequent step. In order to prevent displacement or the like, the laser dicing process is preferably performed in a state where the laminated body 2 with sheets is placed on an adsorption type fixing table 19 and held by suction force, as shown in fig. 3.

In the shaping of the polarizing optical function film laminate 1A, the use of the laminate 2 with a sheet makes it possible to form the coating layers 18a and 18b on the cut end surfaces of the polarizing film 12, particularly on the cut end surfaces of the polarizer 10, simultaneously with the laser dicing. By forming these coating layers 18a and 18b, the "depolarization length" described below can be reduced, in other words, reliability in a high-temperature and high-humidity environment can be improved.

(depolarization length)

When the polarizer 10, which is a main component of the polarizing film 12, is left to stand in a high-temperature and high-humidity environment for a long time, moisture may enter and exit from the cut end surface of the polarizing film to which a heat load is applied, and thus a discoloration phenomenon may occur in which the polyiodide complex contained in the polarizer 10 is denatured, and has fluidity, and leaks from the polarizer 10. As a result, a problem of quality arises that the polarizing function disappears at the end of the polarizer 10. The case where this polarization function is lost is referred to as depolarization, and the width of the region from the cut end face where depolarization has occurred is referred to as depolarization length. Fig. 4A and 4B show optical microscope images showing the depolarization lengths of the cut end surfaces in the direction perpendicular to the light absorption axis of the polarizer, as viewed from above under transmission illumination of crossed nicols. Fig. 4A shows an example of a depolarized polarizing film in which no occurrence of color leakage occurs, and on the other hand, fig. 4B shows an example of a polarizing film in which depolarization occurs due to the reliability test performed in a high-temperature and high-humidity environment. In fig. 4B, the cut edge of the polarizing film 12 is indicated by reference numeral 12a, and color leakage occurs in a region having a width 12B from the cut edge 12 a. The width 12b of this region is the depolarization length.

(coating layer 18 a)

The protective films 11a and 11b of the observation polarizing film 12 and the adhesive (not shown) for bonding the polarizer 10 and the protective films 11a and 11b are usually made of a resin material exhibiting a property of softening or melting by the input of infrared laser energy of a critical value or more. Therefore, at least the protective films 11a and 11b adjacent to the dicing groove 2a can be melted by the thermal energy of the laser during laser dicing processing to form a melt. For convenience, fig. 3 shows only the protective film 11a and a melt formed by the adhesive attached thereto. It is considered that the melt contains a large amount of the components of the protective films 11a and 11b, and flows along the laser-cut end surface of the polarizer 10 exposed by the cutting process, thereby forming a coating layer 18a covering part or all of the cut end surface. Therefore, according to the present embodiment, in the shaping of the polarizing optical function film laminate 1A, the coating layer 18a can be formed on the cut end surface of the polarizing film 12, particularly, on the cut end surface of the polarizer 10 at the same time as the laser dicing, and the reliability in a high-temperature and high-humidity environment can be improved.

The region formed under the influence of the thermal energy of the laser is preferably within a range of 200 μm or less, more preferably 100 μm or less, and particularly preferably 50 μm or less from the cut end face along the surface of the protective film 11. If the thickness exceeds 200 μm, the molten region may leak out from the frame portion of the display panel in a state where the polarizing film 12 is bonded to the display panel, thereby deteriorating the appearance quality.

(coating layer 18 b)

When the laser light penetrates the polarizing optical function film laminate 1A in the thickness direction and reaches the sheet 17, at least the component of the sheet 17 (the 1 st resin component) that is not contained in the polarizing optical function film laminate 1, 1A but is present in a part thereof in the thickness direction, the component of the pressure-sensitive adhesive layer 15 and the release liner 16 (the 2 nd resin component) that is not contained in the polarizing optical function film laminate 1 but may be present in a part thereof in the thickness direction, and the other component that may be contained in the polarizing optical function film laminate 1 are scattered as droplets by the thermal energy of the laser light, and at least a part of the droplets are deposited on the laser-cut end surface formed on the polarizer 10. As a result, the coating layer 18b containing at least the component of the sheet 17 (the 1 st resin component), the component of the pressure-sensitive adhesive layer 15 and the release liner 16 (the 2 nd resin component) in some cases, and other components is formed, and the desired effect can be expected depending on the moisture barrier property (hydrophobicity or moisture permeability) of the formed coating layer 18b. Further, although the degree of influence on the reliability of the cut end of the polarizing film 12 in a high-temperature and high-humidity environment even at the same thickness varies depending on the moisture barrier property (hydrophobicity or moisture permeability) of the formed coating layer, more specifically, regardless of the component or property of the formed coating layer, it is expected that at least a given effect of physically blocking the intrusion of moisture is obtained by forming such a coating layer 18b on the cut end surface. Therefore, according to the present embodiment, the cladding layer 18b can be formed on the cut end surface of the polarizing film 12, particularly on the cut end surface of the polarizer 10, in addition to the cladding layer 18a, at the same time as the laser dicing process in the shape processing of the polarizing optical function film laminate 1A, and the reliability in a high-temperature and high-humidity environment can be improved.

In order to facilitate formation of the coating layer 18b, the width of the scribe groove 2a formed in the sheet 17 is preferably appropriately determined within a range of 5 μm to 300 μm, and the depth of the scribe groove 2a is preferably appropriately determined within a range of 5 μm to 200 μm.

The thickness of the clad layer 18b formed on the cut end surface of the polarizing film 12, more specifically, the length in the direction perpendicular to the surface of the cut end surface of the polarizing film 12 is preferably 10 μm or less. This is because, when the thickness of the clad layer 18b exceeds 10 μm, there is a possibility that the dimensional accuracy of the product is affected, and there is a possibility that a defect is caused when the clad layer is mounted on a target display panel, and there is a possibility that the peeling property of the surface protective film to be peeled off when the clad layer is mounted on the display panel, which is not preferable.

Considering that the component (1 st resin component) of the pressure-sensitive adhesive layer 17b of the sheet 17 constitutes part or all of the covering layer 18b formed on the cut end surface of the polarizing film 12, the thickness of the pressure-sensitive adhesive layer 17b is preferably in the range of 1 μm to 100 μm, more preferably in the range of 5 μm to 50 μm. This is because when the thickness of the pressure-sensitive adhesive layer 17b is less than 1 μm, sufficient adhesive force cannot be obtained, and peeling may occur during transportation, and when the thickness of the pressure-sensitive adhesive layer 17b is more than 100 μm, the total thickness of the laminate 2 with sheets becomes too thick, and the workability is deteriorated. Further, for the purpose of effectively shielding the polarizer from the intrusion of moisture from the outside in a high-temperature and high-humidity environment, a material containing a silicone-based or rubber-based main component exhibiting hydrophobicity is preferably used for the pressure-sensitive adhesive layer 17b, and a material having a hydrophobic group such as an alkyl group such as a methyl group or an ethyl group, or a phenyl group is particularly preferable. Further, the adhesive layer 17b is preferably formed of a material having a low moisture permeability, and the preferred value of the moisture permeability of the material of the adhesive layer 17b is 200g/m RH% under a gas atmosphere of 40 ℃ and 90% RH ² 24h or less, more preferably 150 hg/m ² 24h or less. However, as described above, since a certain effect of physically blocking the penetration of moisture can be expected from the coating layer 18b formed on the cut end face, the components and the like of the pressure-sensitive adhesive layer 17b are not limited to the above-described materials.

Further, when the laser light penetrates through the pressure-sensitive adhesive layer 17b of the sheet 17 and reaches the resin film substrate 17a, the thickness of the resin film substrate 17a is preferably in the range of 10 μm to 150 μm from the viewpoint of preventing damage during processing and the like, because the component (1 st resin component) of the resin film substrate 17a becomes a part of the component constituting the covering layer 18b formed on the cut end surface of the polarizing film 12 together with the component of the pressure-sensitive adhesive layer 17b.

(relationship between coating 18a and coating 18 b)

As is clear from the above description, it is considered that the coating layer 18a contains a large amount of the melt of the protective films 11a and 11b.

On the other hand, it is considered that the coating layer 18b contains a large amount of at least the component (1 st resin component) of the sheet 17 as a component other than the polarizing optical function film laminate 1, 1A, and the components (2 nd resin component) of the pressure-sensitive adhesive layer 15 and the release liner 16 as components other than the polarizing optical function film laminate 1.

As described above, although the clad layer 18a and the clad layer 18b can be clearly distinguished theoretically as shown in the schematic diagram of fig. 3, it is actually difficult to distinguish them. The reason is that the state of the coating layer is easily changed by thermal characteristics such as reactivity of the binder with respect to the laser light used and fluidity during heating. As is clear from the description of the examples and the like described later, both the coating layers 18a and 18b actually become layers containing at least the components of the protective films 11a and 11b and the components obtained by melting and scattering the sheet 17, and further containing the components obtained by melting and scattering the release liner 16, the pressure-sensitive adhesive layer 15, and the like. In other words, since the components of the coating layer 18a and the components of the coating layer 18b are mixed or mixed, there is no need to clearly distinguish the components of the coating layer 18a from the components of the coating layer 18b. The reason is that both the clad layer 18a and the clad layer 18b are formed on the cut end faces of the polarizing film simultaneously with the laser dicing in the shape processing of the polarizing optical function film laminate or the like, and can contribute to improvement in reliability in a high-temperature and high-humidity environment. Therefore, fig. 3 shows only a schematic diagram for ease of explanation. As will be clear from the description below, in the examples and the like, the components contained in the clad layers 18a, 18b were analyzed by TOF-SIMS (time of flight secondary ion mass spectrometry) or energy dispersive X-ray analysis.

Fig. 5 shows an SEM image of a cut cross section of the laminate 2 with sheets as an example of the present invention subjected to laser dicing. Further, fig. 6A shows the effect obtained by the laminated body with sheets 2 according to one embodiment of the present invention and the effect obtained by the end mill in the related art shown in fig. 6B based on the "depolarization length". Fig. 6A shows an example of the depolarization length achieved by example 4 described later, and fig. 6B shows an example of the depolarization length achieved by comparative example 3 described later.

Although the image shown in fig. 5 is not necessarily clear, it is found that the coating layer (18 a) contains a component obtained by melting and scattering the release liner 16 and the sheet 17, as is clear from analysis results by TOF-SIMS and the like shown in examples and the like. Therefore, as is clear from the comparison results of fig. 6A and 6B, the clad layer (18 a) contributes to improvement of the quality reliability of the cut end face of the polarizer 10 in a high-temperature and high-humidity environment.

Although the example in which the pressure-sensitive adhesive layer 15 is provided is shown, the pressure-sensitive adhesive layer 15 is not essential, and even in the case in which the pressure-sensitive adhesive layer 15 is provided, a component of a melt from the pressure-sensitive adhesive layer 15 may not be contained in the coating layer (18 a) depending on the reactivity of the pressure-sensitive adhesive with respect to the laser used and the thermal characteristics such as fluidity at the time of heating. However, since the components of the coating layer 18a and the components of the coating layer 18b are mixed or intermingled, even in such a case, the quality reliability of the cut end surface of the polarizer 10 can be improved.

Fig. 7 shows a cross-sectional SEM image of the vicinity of the polarizing film of the laminated body with a sheet in one example of the present invention (corresponding to example 1 described later) after laser dicing, more specifically, a cross-sectional SEM image of a cut end face in a direction perpendicular to the molecular orientation (light absorption axis) of the polarizer; fig. 8 shows an EDX (energy dispersive X-ray analysis) image of the same site as fig. 7; FIG. 9 shows a cross-sectional SEM image showing the cut end of the polarizer enlarged in the image shown in FIG. 7; fig. 10 shows an EDX image of the same site as fig. 9.

(expansion of polarizer)

When the polarizer 10 made of the PVA-based resin containing iodine is cut by a laser beam, the thickness of the polarizer 10 expands (10 a) at the cut end surface perpendicular to the light absorption axis direction of the polarizer 10 as shown in fig. 7 to 10 compared to the thickness except the vicinity of the cut end surface, and the thickness increases to 1.1 to 2.5 times. This is considered to be because the PVA-based resin containing iodine is subjected to thermal stress by laser energy, and thereby the PVA-based resin contracts in the stretching direction, that is, the light absorption axis direction, and as a result, the PVA-based resin is compressed in the light absorption axis direction and expands in the thickness direction. Along with this phenomenon, the softened or melted protective film 11 and adhesive agent flow into the space generated by compression, and thus the coating layer (18 a) is easily formed. Such a phenomenon is not observed at a cut end surface parallel to the light absorption axis direction of the polarizer 10.

(laser)

From the viewpoint of high productivity, the laser light source preferably includes, for example: CO of 9-11 μm including laser oscillation wavelength in infrared region ₂ Infrared laser of laser light source. The infrared laser can easily obtain a power of several tens of W, and further, the film and the pressure-sensitive adhesive layer constituting the polarizing optical functional film laminate 1A can efficiently release heat by molecular vibration accompanying infrared absorptionThereby, etching accompanying phase transition of the substance can occur.

However, the laser is not limited to the infrared laser, and CO having an oscillation wavelength of 5 μm may be used ₂ A laser light source.

In addition, as the laser light source, if it is a pulse laser light source, a Near Infrared Ray (NIR) light source, a visible light (Vis) light source, and an ultraviolet ray (UV) light source may be used. Examples of NIR, vis, and UV wavelength pulsed laser light sources include: a pulsed laser light source having a laser oscillation wavelength of 1064nm, 532nm, 355nm, 349nm or 266nm (higher harmonic of a solid-state laser light source using Nd: YAG, nd: YLF or YVO4 as a medium), an excimer laser light source having a laser oscillation wavelength of 351nm, 248nm, 222nm, 193nm or 157nm, or an F2 laser light source having a laser oscillation wavelength of 157 nm.

From the viewpoint of suppressing thermal damage to the polarizing film, the oscillation mode of the laser light source is preferably a pulse wave rather than a Continuous Wave (CW). The pulse width at this time may be 10 femtoseconds (10) ^-14 Seconds to 1 millisecond (10) ^-3 Seconds) is appropriately set. The machining may be performed by setting two or more pulse widths. The repetition frequency of the pulse interval is preferably 1 to 1,000khz, and more preferably 10 to 500kHz.

The polarization state of the laser beam is not particularly limited, and linearly polarized light, circularly polarized light, or randomly polarized light can be used.

The spatial intensity distribution of the laser beam is also not particularly limited, but is preferably a gaussian beam which exhibits good light condensing properties, can realize a small spot size, and can be expected to improve productivity. The flat-topped beam may also be shaped using a diffractive optical element, an aspherical lens, or the like.

In order to cut and process the workpiece into a desired shape, the laser beam may be irradiated once along the shape of the target or may be irradiated multiple times to achieve a desired cutting depth. The processing conditions after the 1 st and 2 nd passes can be appropriately adjusted within the above-described ranges.

By using a conventional scanning device such as a stage driving system such as an XY fine adjustment stage, an optical scanning system such as an electrical scanner and a polygon scanner, or a combination thereof (multi-axis synchronous control), the relative position of the polarizing optical function film laminate 1A as a workpiece and the laser light can be changed at a predetermined speed, and laser light irradiation can be controlled on and off by a mechanical shutter mechanism, an AOM (acousto-optic device), or the like, thereby processing the workpiece into a desired shape.

The scanning speed of the laser irradiation may be appropriately set so as to achieve a desired etching depth that can completely cut the polarizing optical function film laminate 1A in the thickness direction and further form a cut groove in the sheet 17 to a sufficient depth.

From the viewpoint of improving the processing efficiency and suppressing the thermal damage, it is preferable to irradiate the polarizing optical function film laminate 1A as the processing target by condensing the laser light with an objective lens such as an F θ lens. The laser beam is preferably a focused spot diameter that can be processed with a cutting width of 500 μm or less, and more preferably a focused spot diameter that can be processed with a cutting width of 300 μm or less. Will decay to 1/e compared to the peak intensity value ² When the point of intensity of (a) is defined as a spot diameter, the spot diameter of the condensed light is preferably 200 μm or less, and more preferably 100 μm or less. In the case of using an electric scanner, a telecentric F θ lens is preferably used in order to vertically irradiate a laser beam to a workpiece.

In order to obtain a desired spot diameter and cut width of the condensed light, a beam expanding unit for adjusting the beam diameter may be disposed in the middle of the optical path from the emission end of the laser oscillator to the objective lens.

The laser power may be appropriately set according to the thickness and properties of the polarizing optical functional film laminate 1A to be processed, and for example, CO may be used ₂ When the laser light source is a laser light source, the laser power is preferably set to a range of 5 to 300W, and more preferably to a range of 20 to 200W.

Two or more kinds of laser light may be irradiated simultaneously, or two or more kinds of laser light may be irradiated step by step.

(processing apparatus)

The laser cutting process of the polarizing functional optical film laminate 1A may be performed while continuously discharging the polarizing functional optical film laminate 1A wound in a roll shape, or the polarizing functional optical film laminate 1A may be cut into individual pieces by cutting into a predetermined length in advance.

When the cutting process is performed on the long strip-shaped film wound in a roll, the polarizing optical function film laminate 1A is continuously or intermittently supplied in a so-called roll-to-roll manner, and during this time, in order to process the film into a desired shape, it is preferable to cut the laminate while performing two-dimensional scanning with the laser light so as to face the polarizing optical function film laminate. In this case, for example, the position of the laser beam irradiated to the polarizing film on the XY two-dimensional plane is changed by mounting and fixing an optical element such as a laser light source and a lens or a mirror on the XY biaxial movable stage and driving the XY biaxial movable stage. In addition, both scanning with a laser light source using an XY biaxial movable stage and scanning with a laser beam using a galvano mirror or the like may be employed (so-called coordinated control). In the laser processing, the conveyance of the long strip-shaped film laminate may be stopped, or the film laminate may be synchronously processed in accordance with the conveyance speed and position while being continuously conveyed.

The suction fixing table for holding the laminated body 2 with the sheet in the process may be provided or may be absent.

In order to suppress the adhesion of the scattered matter, which does not contribute to the formation of the coating layer during the processing, to the product, it is preferable to provide a dust collecting mechanism in the vicinity of the laser irradiation section.

According to the present invention, the amount of the sheet-origin material scattered from the sheet and adhering to the cut end face of the polarizing film by the laser energy received at the laser cutting process can be made to a desired value by appropriately setting the thickness of the sheet. Therefore, it is possible to form a clad layer contributing to improvement in reliability in a high-temperature and high-humidity environment on the cut end surface of the polarizing film simultaneously with the laser cutting process, thereby obtaining a depolarization preventing effect.

Fig. 11 is a schematic view showing an example of a laser cutting apparatus 30 that can be used in a method of continuously performing a laser cutting process in a roll-to-roll manner. In this apparatus 30, a laminate 31 in which a surface protective film 34, a polarizing film 32, and a release liner 36 are laminated, which has the same configuration as the polarizing optical function film laminate 1A shown in fig. 1, is used in a state of being formed in a long strip shape. The long strip-shaped laminated body 31 is wound to form a roll 31a, and the roll 31a is rotatably supported by a roll support portion, not shown. Similarly, the sheet 37 having the same configuration as the sheet 17 is used in a long strip shape. The long strip-shaped sheet 37 is wound to form a roll 37a, and the roll 37a is rotatably supported by a roll support portion, not shown.

The laminate 31 and the sheet 37 continuously fed out from the roll 31a and the roll 37a are fed into a nip of a pair of superimposing rollers 40 in a state of being superimposed on each other. The laminate 31 and the sheet 37 are laminated by the laminating roller 40 to form a laminate 41 with a sheet, and sent to the nip of the second laminating roller 42 at the next stage. At the second folding roller 42, the contamination countermeasure film 43 is fed to the side of the laminated body 41 with sheets to be folded on the surface protection film 34. The contamination prevention film 43 is supplied in a roll form and is rotatably supported by a roll support portion, not shown. The second folding roller 42 functions to bond the contamination prevention film 43 to the surface protection film 34 of the laminated body 41 with sheets and to feed the laminated body 41 with sheets to which the contamination prevention film 43 is bonded to the lower side of the guide roller 44 at the next stage.

A laser irradiation device 45 movable in the X-Y biaxial directions is disposed between the second superimposing roller 42 and the guide roller 44. The laser irradiation device 45 irradiates the laminated body 41 with the sheet with the laser light from the upper side of the contamination prevention film 43, and while this is being performed, the X-Y biaxial movement is performed, so that the dicing groove 46 is formed in the contamination prevention film 43 and the laminated body 41 with the sheet as shown in the lower cross-sectional view in fig. 11. By this cutting groove 46, laser cutting processing of a desired pattern can be performed. As shown in the lower sectional view of fig. 11, the cut groove 46 cuts the laminate 41 with the contamination countermeasure film 43 and the tape sheet in the thickness direction to a depth of a certain degree in the thickness direction of the sheet 37. By the dicing groove 46, a dicing portion 47 having a predetermined pattern is formed on the contamination prevention film 43 and the laminated body 41 with the sheet material.

When the laminate 41 with the tape sheet to which the contamination countermeasure film 43 is bonded passes through the pair of contamination countermeasure film recovery rollers 48, the adhesive surface of the contamination countermeasure film recovery tape 49 formed of an adhesive tape is pressed against the contamination countermeasure film 43, and the contamination countermeasure film 43 is recovered from the upper surface of the laminate 41. Thereafter, in the laminated body 41 with the sheet after passing through the guide roller 44, the product portion divided by the slit groove 46 remains on the sheet 37, and other unnecessary portions (unnecessary materials) are wound up and collected. Then, the laminated body 41 with the product portion remaining thereon is sent to the sheet peeling section 51 after passing through the pair of guide rollers 50. The sheet peeling unit 51 includes a wedge-shaped peeling plate 51a, and the used sheet after the laser cutting process is peeled from the laminate 31 as the product portion on the peeling plate 51 a. The remaining laminate 31 is sent to the product collecting unit 52 and collected as a product. The laminate 31 reaching the product collecting unit 52 may be wound in a roll shape to form a product roll. Fig. 11 shows a configuration in which the unnecessary material and the contamination countermeasure film are collected separately, but the present invention is not limited to this configuration, and the unnecessary material and the contamination countermeasure film may be collected at the same time.

(processing shape)

In order to use the polarizing film 12 included in the polarizing optical functional film laminate of the present invention in various devices including a meter display part of an automobile, a smart watch, a head mount display, a smart phone, a liquid crystal display device such as a notebook computer and a tablet computer, an optical display device such as an organic EL display device, and an optical display panel such as a Plasma Display Panel (PDP), various shapes such as a shape having a curved edge part or a hole may be cut and processed as illustrated in fig. 12A to 14. Here, fig. 12A and 12B are diagrams showing an example of a cutting processing layout when a product cut into a smartphone shape is manufactured from a large polarizing film, in which fig. 12A is a plan view showing the whole and fig. 12B is a plan view showing a part thereof in an enlarged manner; fig. 13A and 13B are views showing examples of a layout of a cutting process when a product cut into an automobile instrument panel shape is manufactured from a large polarizing film, in which fig. 13A is a plan view showing the whole and fig. 13B is a plan view showing a part thereof in an enlarged manner; fig. 14 is a photograph showing an example of a polarizing film cut into a smartphone shape in parallel. Therefore, the present invention can be applied to cutting work of all the shapes described above. By using a laser beam for cutting, it is possible to realize processing having a curved portion with a small curvature radius (R), and it is also possible to correspond to cutting with a curvature radius R of 2mm or less.

For example, in a polarizing film used for an instrument panel of an automobile, a structure in which a through hole is formed is sometimes adopted for fixing a pointer, and for example, it is sometimes required to form a through hole having a diameter of 0.5mm to 100mm, and such a requirement can be met by using a laser cutting technique.

The laser cutting process of the polarizing film 12 can be applied to various shapes, and is not limited to the above shapes.

Further, the laser dicing method can be applied to a step of slit-cutting a long strip-shaped film laminate including a polarizing film in a longitudinal direction by laser light, and the coating layer of the present invention can be formed on a cut end surface of the slit-cut long strip-shaped film laminate. The coating layer can suppress deterioration of the cut end face of the long strip-shaped film laminate due to entry of moisture from the cut end face of the laminate during storage and transportation of the long strip-shaped film laminate.

The laser dicing method can be applied to a fixed-length dicing step of conveying a long strip-shaped film laminate including a polarizing film in a roll-to-roll manner, and dicing the long strip-shaped film laminate in a direction perpendicular to a conveying direction in a state of being stopped after the long strip-shaped film laminate is conveyed at a predetermined feed amount.

Examples

The present invention will be described in more detail with reference to examples and the like. However, the following examples are only for the purpose of facilitating understanding of the present invention and showing that the present invention can be carried into effect, and the present invention is not limited to these examples.

[ Table 1]

/>

[ example 1]

(polarizing optical functional film laminate)

A polymer film having a thickness of 30 μm and containing a PVA based resin as a main component was immersed in 5 liquid baths described in the following [1] to [5] in order while applying a tensile force capable of stretching in the longitudinal direction of the film, and stretched at a stretch ratio of 6 times (polymer film manufactured by Korea corporation). The stretched film was dried to obtain a polarizer 10 having a thickness of 12 μm.

< Condition >

[1] Swelling bath: pure water of 30 DEG C

[2] Dyeing bath: aqueous solution of iodine and potassium iodide at 30 deg.C

[3] 1, crosslinking bath: aqueous solution at 40 ℃ comprising potassium iodide and boric acid

[4] And 2, crosslinking bath: 60 ℃ aqueous solution comprising potassium iodide and boric acid

[5] Washing bath: aqueous solution of potassium iodide at 25 deg.C

A PVA adhesive was applied to one side of the polarizer so that the dried thickness became 100nm, and a long TAC film having a thickness of 25 μm was laminated to align the films in the longitudinal direction, thereby obtaining a protective film 11a.

Next, a PVA adhesive was applied to the other side of the polarizer so that the dried thickness became 100nm, and a long TAC film having a thickness of 25 μm was bonded to the other side of the polarizer so that the longitudinal directions of the TAC films were aligned to obtain a protective film 11b.

Through the above operation, the polarizing film 12 was produced.

Next, a hard coat layer was formed as a surface treatment layer 13 on the main surface of one TAC film 11a on the opposite side to the polarizer so that the thickness after drying became 7 μm, and a surface protection film 14 was further formed thereon. The surface protection film 14 was formed of a polyethylene terephthalate base material (thickness: 38 μm) and an acrylic pressure-sensitive adhesive (thickness: 23 μm).

An acrylic adhesive having a thickness of 12 μm was applied to the main surface of the TAC film 11b on the other side opposite to the polarizer to form an adhesive layer 15, and a release liner 16 made of polyethylene terephthalate was further bonded thereto.

As the acrylic pressure-sensitive adhesive contamination countermeasure film 23 (43), a surface protection film E-MASK manufactured by hiton electric corporation and composed of an acrylic pressure-sensitive adhesive layer (thickness 20 μm) and a polyethylene terephthalate base material (thickness 38 μm) was stuck to the main surface of the surface protection film 14 of the polarizing optical function film laminate 1A.

In this order, a polarizing optical function film laminate 1A having a total thickness of about 180 μm and having a configuration of contamination countermeasure film 23/surface protection film 14/hard coat 13/TAC film 11A/PVA based adhesive/polarizer 10/PVA based adhesive/TAC film 11 b/pressure-sensitive acrylic adhesive layer 15/release liner 16 was obtained.

(laser)

Laser oscillator using CO ₂ Laser light (J-3, 9.4 μm wavelength, gaussian beam, pulse oscillation, manufactured by Coherent Co., ltd.) was focused on a theoretical spot diameter (1/e of peak value) by an objective lens ² The spot diameter was defined by the intensity of (b) to about 90 μm, and then a desired machining shape was scanned once at a laser power of 65W, a repetition frequency of 30kHz, and a scanning speed of 500mm/s using an X-Y stage and an electric scanner in combination, and the workpiece was cut into a rectangular shape having dimensions of 80mm × 50 mm.

(sheet)

A sheet 17 composed of a silicone adhesive layer 17b (thickness: 75 μm) and a polyethylene terephthalate base material 17a (thickness: 75 μm, T100-75S, manufactured by Mitsubishi chemical corporation) was bonded to the main surface 16a of the release liner 16 of the polarizing optical function film laminate 1A via the silicone adhesive layer 17b.

(laser cutting processing)

The polarizing optical functional film laminate 1A to which the sheet 17 and the contamination prevention film 43 are attached is subjected to laser dicing processing of a desired shape by using various laser conditions described under the above-mentioned "laser". By this laser cutting process, it was confirmed that: the polarizing optical function film laminate 1A is cut completely through the entire thickness together with the silicone-based pressure-sensitive adhesive layer 17b of the sheet 17, while the polyethylene terephthalate substrate 17a is cut into half-cut pieces without being completely cut.

After the laser dicing process, the contamination countermeasure film 43 was peeled off, and the height of the burr formed on the cut end face of the surface protection film 14 was measured, and as a result, it was 3 μm, and it was confirmed that it was a sufficiently low value.

In addition, on the cut end face in the direction perpendicular to the stretching direction of the polarizer 10, that is, in the direction perpendicular to the orientation direction of the PVA-based molecules, the thickness of the polarizer is 1.8 times as large as the thickness of the polarizer other than the vicinity of the cut end face.

(evaluation)

The sheet 17 and the contamination countermeasure film 43 were peeled from the sample of the polarizing film cut into a rectangular shape by the laser beam, the cut surface was embedded with an epoxy resin, and the state of the cut cross section was observed by an FE-SEM (scanning electron microscope, JSM-7001F, manufactured by japan electronics corporation), and SEM images were obtained (fig. 7 and 9).

Further, an SEM image was obtained by observing the state of the cut end surface of the polarizer 10, that is, the state of the clad layer from the molecular orientation direction using the FE-SEM (fig. 15A). Fig. 15A is an SEM image in example 1, and corresponds to an SEM image observed from the direction of arrow "C" in fig. 9. For comparison, the same SEM images in example 2 are shown in fig. 15B, and further the same SEM images in comparative examples 1 and 2 are shown in fig. 15C and 15D, respectively.

From these images, it is understood that the cut end surfaces of the polarizer 10 are reliably covered with the covering layers 18a and 18b.

In order to obtain information on the substances contained in the coating layers 18a and 18b, elemental analysis (fig. 8 and 10) by EDX (Energy dispersive X-ray analysis, energy250, product of Oxford Instruments) was performed on the same site as fig. 9. Fig. 8 and 10 are EDX images obtained by software processing in the case where silicon is contained in the cladding layers 18a and 18b in order to make the silicon glitter and display images. As is clear from fig. 10, in particular, the coating layer 18b formed on the cut end face of the polarizing film contains silicon (Si element) derived from the silicone-based pressure-sensitive adhesive layer 17b constituting the sheet 17. The thickness of the coating layer 18b is about 2 to 5 μm.

In order to further obtain information on the substances contained in the coating layers 18a and 18b, analysis by TOF-SIMS was performed on the sites corresponding to the same sites in fig. 9 using a time-of-flight secondary ion mass spectrometer of ULVAC-PHI co. Further, attention was paid to C derived from PET obtained by analysis ₈ H ₅ O ₄ ^- (m/z 165) (m/z represents mass to charge ratio), the data were mapped. Fig. 16 shows an image showing the analysis result. From this image, it was confirmed that a film of polyethylene terephthalate (PET) was formed in the coating layer 18a as well as in the coating layer 18b.

Further, the laser irradiated portion of the peeled sheet was confirmed, and as a result, the dicing groove 17-1a formed by dicing using laser energy was confirmed to have a width of 40 μm and a depth of about 100 μm. This indicates that at least the components of the sheet 17 scattered from the slit grooves 17-1a adhere to the slit end surfaces of the polarizing film 12, and the covering layers 18a and 18b are formed (fig. 17).

Fig. 18 is a graph showing the result of analyzing the composition of the material contained in the coating layers 18a and 18b of example 1. More specifically, it is a graph showing EDX element analysis results at a portion indicated by an arrow "B" in fig. 10, in which the horizontal axis represents X-ray energy (keV) and the vertical axis represents X-ray count, respectively. As shown in this figure, in the present embodiment, carbon (C) and oxygen (O) are detected from the clad layers 18a and 18b in addition to silicon (Si). It can be seen that the clad layers 18a and 18b formed on the cut end surfaces of the polarizer 10 are layers formed by mixing at least the organic component derived from the polarizing film 12, the adhesive layer 15, the release liner 16, and the sheet, and the silicon (Si) derived from the adhesive layer 17b of the sheet.

(test of reliability in high-temperature and high-humidity Environment)

The surface protective film 14 and the release liner 16 were peeled from the sample of the produced rectangular polarizing optical functional film laminate 1A, and the surface of the pressure-sensitive adhesive layer 15 was bonded to a glass plate so as to be in contact with the glass plate. In this state, the test piece was placed in an oven set to an environment of 65 ℃ and 90% humidity, and subjected to a reliability test. The reliability test was carried out under conditions such that the sample was held in the oven in the above-described environment for 240 hours (10 days), and depolarization due to color leakage of polarizing film 12 was observed on the processed end face in the high-temperature and high-humidity environment.

(confirmation of evaluation result of reliability of machined end)

The sample subjected to the reliability test was observed with an optical microscope (cross nicol, transmission illumination), and the depolarization length of the cut end portion after the laser cutting was measured based on the above definitions with respect to fig. 4A and 4B.

As a result of the measurement, the depolarization length of the cleaved end face (oriented parallel face) of the polarizer parallel to the light absorption axis was 135 μm, and the depolarization length of the cleaved end face (oriented split face) perpendicular to the light absorption axis was 183 μm. It is understood that the depolarization length is suppressed as compared with the comparative example described later.

[ example 2]

In the sheet 17, laser dicing processing and evaluation of depolarization by color leakage of the polarizer 10 were performed under the same conditions as in example 1 except that an acrylic pressure-sensitive adhesive layer (thickness 23 μm) was used as the pressure-sensitive adhesive layer 17b, a polyethylene terephthalate substrate (thickness 38 μm) was used as the resin film substrate 17a, and the laser power was changed to 55W.

As a result, the depolarization length of the cut end surface of the polarizer 10 parallel to the light absorption axis was 153 μm, and the depolarization length of the cut end surface perpendicular to the light absorption axis was 216 μm. The depolarization length was suppressed as compared with the comparative example described later.

[ example 3]

In the sheet 17, laser dicing processing and evaluation of depolarization by color leakage of the polarizer 10 were performed under the same conditions as in example 1 except that a rubber-based pressure-sensitive adhesive layer (thickness 10 μm) was used as the pressure-sensitive adhesive layer 17b, a polyethylene terephthalate substrate (thickness 38 μm) was used as the resin film substrate 17a, and the laser power was changed to 55W.

As a result, the depolarization length of the cut end face of the polarizer parallel to the light absorption axis was 120 μm, and the depolarization length of the cut end face perpendicular to the light absorption axis was 191 μm. The depolarization length was suppressed as compared with the comparative example described later.

[ example 4]

Laser dicing and evaluation of depolarization by color leakage of the polarizer 10 were performed under the same conditions as in example 2, except that the thickness of the polarizer 10 was set to 5 μm, the protective film 11b was removed, a base material having a silicone adhesive layer of 20 μm in thickness was used, and the laser power was changed to 35W. Fig. 5 corresponds to an SEM image in which the contamination countermeasure film was removed from the structure of example 4.

As a result, the depolarization length of the cut end face of the polarizer parallel to the light absorption axis was 113 μm, and the depolarization length of the cut end face perpendicular to the light absorption axis was 103 μm. The depolarization length was suppressed as compared with comparative example 3 described later.

Comparative example 1

Evaluation was performed under the same conditions as in example 1 except that the polarizing optical function film laminate 1A described in example 1 was cut into a predetermined shape, that is, a rectangular shape having dimensions of 80mm × 50mm by using an end mill without using a sheet and the contamination prevention film 23.

As a result, the depolarization length of the cut end face of the polarizer parallel to the light absorption axis was 182 μm, and the depolarization length of the cut end face perpendicular to the light absorption axis was 251 μm. The depolarization length was larger than those of examples 1 and 2.

Comparative example 2

Laser dicing and depolarization by color leakage of the polarizer 10 were evaluated under the same conditions as in example 1, except that no sheet was used and the laser power was changed to 55W. At this time, it was confirmed that: the polarizing optical function film laminate 1A is cut completely, while the release liner 16 is cut into half-cut pieces without being completely cut.

As a result, the depolarization length of the cut end face of the polarizer parallel to the light absorption axis was 170 μm, and the depolarization length of the cut end face perpendicular to the light absorption axis was 231 μm. The use of the infrared laser beam produces an effect of coating the end portion of the polarizer with a molten material of the protective film, and a small improvement is observed as compared with comparative example 1, but the effect of suppressing depolarization is weak as compared with example 1 and example 2 described above.

Comparative example 3

The polarizing optical functional film laminate 1A described in example 4 was subjected to end mill machining under the same conditions as in comparative example 1 without using a sheet and the contamination prevention film 23, and the obtained shape-machined sample was evaluated.

As a result, the depolarization length of the cleaved end face of the polarizer 10 parallel to the light absorption axis was 129 μm, and the depolarization length of the cleaved end face perpendicular to the light absorption axis was 177 μm. The depolarization length was larger than that of example 4.

[ example 5]

Laser dicing and depolarization by color leakage of the polarizer 10 were evaluated under the same conditions as in example 1, except that the contamination prevention film 23 was not used, the laser power was changed to 43W, and the repetition frequency was changed to 15 kHz.

As a result, the depolarization length of the cleaved end face of the polarizer parallel to the light absorption axis was 122 μm, and the depolarization length of the cleaved end face perpendicular to the light absorption axis was 195 μm. The depolarization length was suppressed as compared with the comparative example described later.

[ example 6]

Analysis by TOF-SIMS was performed under the same conditions as in example 2 except that the contamination prevention film 23 was not used, the laser power was changed to 39W, and the repetition frequency was changed to 15kHz, and laser dicing processing and depolarization by color bleed of the polarizer 10 were evaluated.

Fig. 19 is an image showing the analysis result based on TOF-SIMS. From this figure, it is confirmed that a film of polyethylene terephthalate (PET) is formed in the coating layer 18a as well as the coating layer 18b.

The depolarization length of the cut end face of the polarizer parallel to the light absorption axis was 132 μm, and the depolarization length of the cut end face perpendicular to the light absorption axis was 214 μm. The depolarization length was suppressed as compared with the comparative example described later.

[ example 7]

Analysis by TOF-SIMS was performed under the same conditions as in example 2, except that the contamination prevention film 23 was not used, the laser power was changed to 20W, the repetition frequency was changed to 15kHz, and the number of scans was changed to 2, and laser dicing processing and depolarization by color leakage of the polarizer 10 were evaluated.

Fig. 20 is an image showing the analysis result based on TOF-SIMS. As can be seen from this figure, not only the coating layer 18b, but also a polyethylene terephthalate (PET) film is formed in the coating layer 18a.

The depolarization length of the cut end face of the polarizer parallel to the light absorption axis was 133 μm, and the depolarization length of the cut end face perpendicular to the light absorption axis was 233 μm. The depolarization length was suppressed as compared with the comparative example described later.

It is clear that by decreasing the laser power and increasing the number of scans, results comparable to those obtained when the laser power was high and the number of scans was small were obtained.

Comparative example 4

Analysis by TOF-SIMS was performed under the same conditions as in example 5, except that the sheet was not used and the laser power was changed to 20W, and laser dicing processing and depolarization by color leakage of the polarizer 10 were evaluated. At this time, it was confirmed that: the release liner 16 of the polarizing optical functional film laminate 1A is not completely cut, but cut into a half-cut state.

Fig. 21 is an image showing the analysis result based on TOF-SIMS. From this figure, it was confirmed that a film of polyethylene terephthalate (PET) was not formed in the clad layers 18a, 18b.

The depolarization length of the cut end face of the polarizer parallel to the light absorption axis was 158 μm, and the depolarization length of the cut end face perpendicular to the light absorption axis was 235 μm. The depolarization length was larger than that of example 5.

Comparative example 5

Analysis by TOF-SIMS was performed under the same conditions as in example 6, except that no sheet was used and the laser power was changed to 27W, and laser cutting and depolarization by color leakage of the polarizer 10 were evaluated.

In this laser dicing process, the polarizing optical functional film laminate 1A was completely cut, and the dicing process was confirmed to be a full-cut state. Here, since no sheet is provided, the laser light is in a completely leaked state in the irradiation direction.

Fig. 22 is an image showing the analysis result based on TOF-SIMS. From this figure, it was confirmed that a film of polyethylene terephthalate (PET) was not formed in the clad layers 18a, 18b.

The depolarization length of the cut end face of the polarizer parallel to the light absorption axis was 163 μm, and the depolarization length of the cut end face perpendicular to the light absorption axis was 268 μm. The depolarization length was larger than that of example 6.

[ reference example 1]

Analysis by TOF-SIMS was performed under the same conditions as in example 1, except that the contamination prevention film 23 and the surface protection film 14 were not used.

Fig. 23 is an image showing the analysis result based on TOF-SIMS. From this figure, it is confirmed that a film of polyethylene terephthalate (PET) is formed in the coating layer 18a as well as the coating layer 18b.

This result shows that a film of polyethylene terephthalate (PET) can be formed in the clad layers 18a, 18b even in the absence of the contamination countermeasure film 23 and the like.

[ reference example 2]

TOF-SIMS-based analysis was performed under the same conditions as in example 1, except that the release liner 16 and the sheet 17 were not used. The polarizing optical functional film laminate 1 and the adhesive layer 15 were cut completely by laser dicing.

Fig. 24 is an image showing the analysis result based on TOF-SIMS. As can be seen from this figure, the coating layer 18a is not limited to the coating layer 18b, and a polyethylene terephthalate (PET) film is not formed.

This result shows that, when a release liner or a sheet is not used, a film of polyethylene terephthalate (PET) is not formed in the clad layers 18a and 18b even if the contamination countermeasure film 23 or the like is present.

[ examination ]

The coating layers 18a and 18b contain at least a component of the sheet 17, i.e., a component of the adhesive layer 17b and/or a PET component of the resin film substrate 17 a. Therefore, by appropriately selecting the components of these sheets, particularly the adhesive layer 17b, it is possible to effectively prevent moisture from entering the polarizer 10 from the outside through the cut end face, and it is possible to expect prevention of color leakage, that is, reduction in the depolarization length.

In addition, in the case where the polarizing optical function film laminate 1 is a laminate constituting the polarizing optical function film laminate 1A including the pressure-sensitive adhesive layer 15 and the release liner 16, the components of the pressure-sensitive adhesive layer 15 and further the PET component from the release liner 16 make the coating layers 18a and 18b thicker, and the penetration of moisture can be more effectively prevented.

Claims (12)

1. A polarizing optical function film laminate having at least a polarizing film comprising a polarizer and a protective film laminated on at least one side of the polarizer, and having a given shape formed by cut end faces,

wherein a coating layer containing a component of a resin material not contained in the polarizing optical function film laminate as a 1 st resin component is formed on at least a cut end face of the polarizer among the cut end faces,

at least a part of the cut end surface extends in a direction intersecting with a light absorption axis direction of the polarizer, and a thickness of the polarizer in the cut end surface is 1.1 times or more and 2.5 times or less larger than a thickness of the polarizer other than a vicinity of the cut end surface.

2. The polarizing optical function film laminate according to claim 1, wherein a release liner is releasably attached to one surface of the polarizing optical function film laminate via an adhesive layer, and the cladding layer contains a component of the adhesive layer and/or the release liner as a 2 nd resin component in addition to the 1 st resin component.

3. The polarizing optical function film laminate according to claim 1 or 2, wherein the coating layer has a moisture permeability of 200g/m in a gas atmosphere having a temperature of 40 ℃, a humidity of 90% RH ² Materials below 24 h.

4. The polarizing optical functional film laminate according to any one of claims 1 to 3, wherein the coating layer comprises any polymer material selected from acrylic, rubber, urethane, silicone, olefin, or polyester.

5. The polarizing optical function film laminate according to any one of claims 1 to 4, wherein the cladding layer contains a component of the protective film and/or a component of an adhesive that bonds the polarizer and the protective film.

6. The polarizing optical function film laminate according to any one of claims 1 to 5, wherein the protective film comprises a cellulose-based resin, (meth) acrylic resin, cycloolefin-based resin, olefin-based resin, ester-based resin, polyamide-based resin, polycarbonate-based resin.

7. The polarizing optical function film laminate according to any one of claims 1 to 6, wherein a cut end face of the surface protective film laminated on one surface of the polarizing film has burrs of 0 to 20 μm inclusive.

8. The polarizing optical function film laminate according to any one of claims 1 to 7, wherein a surface treatment layer for the purpose of hard coating treatment, antireflection treatment, and antiglare treatment is laminated on one surface of the polarizing film.

9. The polarizing optical functional film laminate according to any one of claims 1 to 8, which is mounted on a liquid crystal display device, an organic EL display device, or a Plasma Display Panel (PDP) including an instrument display portion of an automobile, a smart watch, a head-mounted display, a smart phone, a tablet computer, and a notebook computer.

10. The polarizing optical function film laminate according to any one of claims 1 to 9, wherein the thickness of the clad layer is 10 μm or less.

11. A polarizing film for the polarizing optical functional film laminate according to any one of claims 1 to 10.

12. The polarizing film of claim 11, wherein the polarizing film is wound in an elongated shape.

Images