JP2014191205A - Production method of laminate optical film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a laminate optical film comprising a release film, an adhesive layer, an optical film and a surface protective film, layered in this order, by which the surface protective film can be inhibited from peeling from the optical film on a cut surface when the laminate is cut.SOLUTION: The production method of a laminate optical film includes a step of cutting a laminate comprising a release film, an adhesive layer, an optical film and a surface protective film, layered in this order, while leaving the release film. The cutting step is carried out by moving a rotating cutting blade, in which the rotation direction of the rotating cutting blade is in the same direction as the moving direction of the cutting blade, and a ratio (B/A×100) of the rotational speed B to the moving speed A of the rotating cutting blade is 90% or more.

Description

  The present invention relates to a method for producing a laminated optical film.

  A polarizing plate, which is an example of an optical film, is used in many scenes as a constituent member of a liquid crystal display device. In recent years, the demand for the polarizing plate is rapidly increasing. In addition, the use of high-value-added polarizing plates having an optical compensation function, a brightness enhancement function, and the like is increasing, and the demand for display quality tends to increase further.

  In general, the polarizing plate is cut from a raw sheet of a long sheet with a predetermined shape and dimensions and mounted on a panel of a liquid crystal display device. In the original sheet of the long sheet, a release film or the like is laminated via an adhesive layer in addition to the polarizing plate.

  Various methods are known as a polarizing plate cutting method. For example, a method of cutting the polarizing plate and the pressure-sensitive adhesive layer to a predetermined size without cutting the original release film of the long sheet (such a cutting is referred to as a half cut) is known (for example, Patent Document 1). The polarizing plate and the pressure-sensitive adhesive layer cut to the predetermined size are peeled off from the release film, and then the polarizing plate is continuously bonded to an adherend such as a panel via the pressure-sensitive adhesive layer (for example, Patent Documents). 1).

  Also, a method of cutting an end face of a polarizing plate laminate including a polarizing plate comprising a polarizing film made of a polyvinyl alcohol-based resin and a stretched polyethylene terephthalate film using a specific cutting rotator is known. (For example, refer to Patent Document 2).

  Further, as a polarizing plate cutting method, a method of cutting a laminated film having an optical film by moving the blade in a fixed state is known (for example, see Patent Document 3).

International Publication No. 2008/047712 Pamphlet JP2012-203210A JP 2010-30035 A

  However, in Patent Document 1, half cutting is performed by a laser, and there are problems such as apparatus cost and maintenance load. Therefore, other means such as processing with a blade have been desired. Further, the cutting method disclosed in Patent Document 2 is an end surface processing method that uses a specific cutting rotator to scrape off the end face of the polarizing plate laminate and finish the end face in a good state. The polarizing plate has a predetermined shape and dimensions. Not trying to cut into. Furthermore, in Patent Document 3, the object is mainly to suppress delamination (partial peeling phenomenon at the cut surface between the polarizer and the polarizer protective film laminated via an adhesive). When having a surface protective film on a film, there existed a problem that the said protective film will partly peel from an optical film in a cut surface (floating of a surface protective film). As described above, when the surface protective film floats on the cut surface, there is a problem that the end of the optical film is contaminated.

 Then, this invention suppresses that the said surface protection film peels from an optical film in the cut surface at the time of cut | disconnecting the laminated body on which the peeling film, the adhesive layer, the optical film, and the surface protection film were laminated | stacked in this order. An object of the present invention is to provide a method for producing a laminated optical film.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above object can be achieved by the production method shown below, and have completed the present invention.

That is, the present invention is a method for producing a laminated optical film comprising a step of cutting a laminate in which a release film, an adhesive layer, an optical film, and a surface protective film are laminated in this order, leaving the release film. And
The step of cutting is performed by moving a rotating cutting blade,
The rotating direction of the rotating cutting blade is the same direction as the moving direction of the cutting blade, and the ratio (B / A × 100) of the rotating speed B to the moving speed A of the rotating cutting blade is 90% or more. The present invention relates to a method for producing a laminated optical film.

  The surface protective film is preferably laminated on the optical film via an adhesive layer.

  The optical film is preferably a polarizing plate having a polarizer and a transparent protective film laminated on at least one surface of the polarizer.

  The polarizing plate is a long polarizing plate, and it is preferable to cut the laminate in the width direction of the long polarizing plate.

  According to the production method of the present invention, in the cut surface when the release film, the pressure-sensitive adhesive layer, the optical film, and the surface protective film are laminated in this order, the cut surface when the release film is cut, the surface protection is performed. It can suppress that a film peels from an optical film. Accordingly, the laminated optical film obtained by the production method of the present invention is appropriately laminated with a surface protective film until the time of use of the optical film, and can be a laminated optical film having high contamination resistance. A polarizing plate with little contamination during actual use can be provided.

(A) It is a conceptual diagram which shows the one aspect | mode of the manufacturing method of this invention. (B) It is an enlarged view of the part enclosed with the dotted line in Fig.1 (a). (A) It is a conceptual diagram which shows the cutting device used by this invention. (B) It is A-A 'sectional drawing in Fig.2 (a).

The production method of the laminated optical film of the present invention includes a step of cutting the laminate in which the release film, the pressure-sensitive adhesive layer, the optical film, and the surface protective film are laminated in this order, leaving the release film,
The step of cutting is performed by moving a rotating cutting blade,
The rotating direction of the rotating cutting blade is the same direction as the moving direction of the cutting blade, and the ratio (B / A × 100) of the rotating speed B to the moving speed A of the rotating cutting blade is 90% or more. It is characterized by being.

  The production method of the present invention will be described in detail with reference to the drawings. The release film, optical film, and surface protective film used in the production method of the present invention are not particularly limited, and known ones used in image display devices such as liquid crystal display devices can be used. Among them, preferable ones will be described later.

  FIG. 1 shows a method for producing a laminated optical film of the present invention. FIG. 1A is a diagram showing a traveling direction and a rotating direction of a cutting blade used for cutting, and FIG. 1B is an enlarged view of a portion surrounded by a dotted line in FIG.

  The method for producing a laminated optical film according to the present invention comprises a laminate 1 in which a release film 15, an adhesive layer 14, an optical film 13, and a surface protective film 11 are laminated, with a rotating cutting blade (round blade) 2, It includes a step of cutting (half-cutting) leaving only the release film 15. The optical film 13 and the surface protective film 11 are laminated via an adhesive layer 12 as necessary, as will be described later.

  Here, as shown in FIG. 1B, half cutting means that the cutting edge 21 of the cutting blade 2 cuts up to the adhesive layer 14 of the laminate 1 (point a in the figure), and cuts the release film 15. It is not. The blade edge 21 half-cuts the laminate 1 from point b to point a in the figure. The cut thickness B half-cut by the round blade 21 is a distance from the point b to the point p, and is a thickness obtained by adding the thicknesses of the surface protective film 11, the adhesive layer 12, the optical film 13, and the adhesive layer 14. is there. Further, in FIG. 1B, the cutting edge 21 does not cut the release film 15, but there is no problem if the release film 15 is cut to such an extent that the release film 15 can remain without being broken. As one preferred embodiment, the cut can be made up to about 40 to 60% of the thickness of the release film 15.

  In the present invention, as shown in FIG. 1A, the rotation direction 4 of the rotating cutting blade 2 is the same direction (forward direction) as the moving direction 3 of the cutting blade, and the movement of the rotating cutting blade 2 The ratio of the rotational speed B to the speed A (B / A × 100) is 90% or more.

  In the present invention, the ratio of the rotational speed B to the moving speed A of the rotating cutting blade may be 90% or more, and each speed is not particularly limited. For example, the moving speed A of the cutting blade 2 is 1 to 2000 mm / sec, preferably about 100 to 1000 mm / sec. Moreover, the rotational speed B of a cutting blade can mention about 0.9-2000 mm / sec, and it is preferable that it is about 100-1500 mm / sec.

  In the present invention, as described above, the ratio (B / A × 100) of the rotational speed B to the moving speed A of the rotating cutting blade is 90% or more, and preferably 100% or more. Moreover, although the upper limit of a ratio is not specifically limited, For example, it is preferable that it is 300% or less. In the present invention, when the ratio of the rotational speed B to the moving speed A of the rotating cutting blade is 90% or more, the contact time of the cutting blade with respect to the optical film can be increased. The surface protection film can be prevented from floating.

  FIG. 2 shows one embodiment of a cutting apparatus used for cutting according to the present invention. However, the cutting apparatus used in the manufacturing method of the present invention is not limited to the apparatus shown in FIG.

  As shown in FIG. 2A, the laminate 1 can be a long laminate 1 (L in FIG. 2 is the longitudinal direction and W is the width direction).

  The cutting device 5 includes a cutting blade (round blade) 2 having a double-edged blade edge, and a moving mechanism 6 configured to reciprocate the cutting blade 2 in a cutting movement direction M (broken arrow in FIG. 2). The cutting blade 2 is configured to rotate during half-cutting. Moreover, in order to set cutting thickness which is the distance which the blade edge | tip 21 of the cutting blade 2 penetrate | invades in the thickness direction from the surface of the laminated film 1, and cut | disconnects the cutting device 5 from the surface of the laminated body 1 according to cutting | disconnection thickness. It is comprised so that the installation distance of this cutting blade 2 can be set. For example, the moving mechanism 6 can be configured so as to be vertically movable and fixed with respect to the surface of the laminated body 1, or only the cutting blade 2 can be configured to be vertically moved and fixed with respect to the surface of the laminated body 1.

  On the opposite side of the cutting device 5 with the laminated body 1 interposed therebetween, a cutting receiving plate 7 having an adsorption mechanism for holding the surface of the laminated body 1 flat when cutting with the cutting blade 2 is provided. When the laminate 1 is curled in the width direction, it is preferable to install tension means such as a nip roller for applying tension to both ends of the laminate 1 with the cutting device 5 interposed therebetween. The tension force is set so that the release film does not break during or after the half cut.

  Moreover, the cutting device 5 is provided with clamping means 8 for clamping the surface of the laminate 1 at the time of cutting, and is installed on both sides of the cutting blade 2 at the time of cutting as shown in FIG. The clamp means 8 can suppress the surface of the laminated body 1 and can suppress the floating of the laminated body 1 at the time of cutting.

  The cutting blade 2 used in the present invention is a round blade, and the outer diameter size of the round blade is appropriately set in consideration of ease of handling, device cost, compactness of the device, advantages of blade edge replacement, and the like. However, for example, the outer diameter size is preferably about 100 to 500 mm, and more preferably about 150 to 250 mm.

  The cutting edge 21 may be single-edged or double-edged, but when the cutting blade is single-edged, the cutting stress is concentrated on the side having no blade angle, and the cutting state changes on both sides. Is preferred. Examples of the blade angle of the blade edge 21 include 20 ° to 30 °.

  The cutting direction of the laminate 1 is not particularly limited. For example, as shown in FIG. 2A, the laminate 1 is a long laminate 1 and the optical film is a polarizing plate. The polarizing plate can be cut in the width direction of the polarizing plate.

  As described above, the release film, the pressure-sensitive adhesive layer, the optical film, and the surface protective film used in the production method of the present invention are not particularly limited, and known ones used in image display devices such as liquid crystal display devices can be used. Among them, preferred ones are described below.

(1) Optical film As an optical film, what is used for formation of image display apparatuses, such as a liquid crystal display device, is used, and the kind in particular is not restrict | limited. For example, a polarizing plate is mentioned as an optical film. A polarizing plate having a transparent protective film on one or both sides of a polarizer is generally used.

  The polarizer is not particularly limited, and various types can be used. Examples of the polarizer include hydrophilic polymer films such as polyvinyl alcohol (PVA) film, partially formalized PVA film, and ethylene / vinyl acetate copolymer partially saponified film, and iodine and dichroic dyes. Examples include uniaxially stretched films by adsorbing a dichroic material, polyene-based oriented films such as PVA dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a PVA polarizer comprising a PVA film and a dichroic substance such as iodine is preferable.

  As the PVA polarizer, a PVA resin film that is dyed with a dichroic substance (typically iodine or a dichroic dye) and uniaxially stretched is used. The polymerization degree of the PVA resin constituting the PVA resin film is preferably 100 to 10,000, and more preferably 1000 to 5,000. If the degree of polymerization is too low, the film tends to be stretched when performing predetermined stretching, and if the degree of polymerization is too high, tension may be abnormally required for stretching, and mechanical stretching may not be possible. Moreover, it is preferable that the average saponification degree of PVA resin is about 85-100 mol%, and it is more preferable that it is 90-100 mol%.

  The PVA-based resin film constituting the polarizer can be formed by any appropriate method (for example, a casting method in which a solution obtained by dissolving a resin in water or an organic solvent is cast, a casting method, an extrusion method). it can. The thickness of the PVA-based resin film is usually about 10 to 300 μm, and preferably about 30 to 75 μm.

  As a manufacturing method of the polarizer, any appropriate method is adopted depending on the purpose, material used, conditions, and the like. For example, the system which uses the said PVA-type resin film for a series of manufacturing processes including a swelling, dyeing | staining, bridge | crosslinking, extending | stretching, water washing, and a drying process is employ | adopted normally. In each processing step excluding the drying step, the treatment can be performed by immersing the PVA resin film in a liquid containing the solution used in each step. The order, number of times, and presence / absence of each treatment of swelling, dyeing, crosslinking, stretching, washing with water, and drying can be appropriately set according to the purpose, materials used, conditions, and the like. For example, several processes may be performed simultaneously in one step, and a swelling process, a dyeing process, and a crosslinking process may be performed simultaneously. In addition, for example, it is possible to appropriately employ the crosslinking treatment before and after the stretching treatment. For example, the water washing process may be performed after all the processes, or may be performed only after a specific process.

  The thickness of the polarizer is not particularly limited, but is preferably about 1 to 35 μm. If the thickness of the polarizer is too thin, there is a tendency to be easily damaged when it is bonded to the transparent protective film. On the other hand, if the thickness of the polarizer is too thick, the drying efficiency tends to deteriorate, which is not preferable in terms of productivity.

  Various types of transparent protective films can be used. Moreover, when providing a transparent protective film on both surfaces of a polarizer, the same transparent protective film may be sufficient and a different transparent protective film may be sufficient.

  Examples of the material constituting the transparent protective film include thermoplastic resins that are excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and the like. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins such as polyethylene terephthalate (PET), polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, Examples thereof include a polyimide resin, a polyolefin resin, a cycloolefin resin, a (meth) acrylic resin, a polyarylate resin, a polystyrene resin, a PVA resin, and a mixture thereof. Further, thermosetting resins such as (meth) acrylic resins, urethane resins, acrylic urethane resins, epoxy resins, and silicone resins, or ultraviolet curable resins may be used. Among these, a cellulose resin and a (meth) acrylic resin are preferable. One or more kinds of arbitrary appropriate additives may be contained in the transparent protective film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, a coloring inhibitor, a flame retardant, a nucleating agent, an antistatic agent, a pigment, and a coloring agent.

  A commercially available product can also be used as the film containing the cellulose resin. Examples of commercially available triacetyl cellulose films include trade names “UV-50”, “UV-80”, “SH-80”, “TD-80U”, and “TD-TAC” manufactured by FUJIFILM Corporation. , “TD-60UL”, “UZ-TAC”, “KC series” manufactured by Konica Minolta, and the like.

  The glass transition temperature (Tg) of the (meth) acrylic resin is preferably 100 ° C. or higher, more preferably 105 ° C. or higher, further preferably 110 ° C. or higher, and particularly preferably 115 ° C. or higher. When Tg is within the above range, a polarizing plate having excellent heat resistance can be produced. Moreover, although the upper limit of Tg of the said (meth) acrylic-type resin is not specifically limited, From a viewpoint of a moldability etc., it is preferable that it is 150 degrees C or less.

  Any appropriate (meth) acrylic resin can be adopted as the (meth) acrylic resin within a range not impairing the effects of the present invention. For example, poly (meth) acrylic acid ester such as polymethyl methacrylate, methyl methacrylate- (meth) acrylic acid copolymer, methyl methacrylate- (meth) acrylic acid ester copolymer, methyl methacrylate-acrylic acid ester- (Meth) acrylic acid copolymer, (meth) methyl acrylate-styrene copolymer (MS resin, etc.), a polymer having an alicyclic hydrocarbon group (for example, methyl methacrylate-cyclohexyl methacrylate copolymer, Methyl methacrylate- (meth) acrylate norbornyl copolymer, etc.). Among these, poly (meth) acrylic acid ester obtained by polymerizing (meth) acrylic acid ester having an alkyl group having 1 to 6 carbon atoms can be mentioned.

  Specific examples of the (meth) acrylic resin include “Acrypet VH”, “Acrypet VRL20A” manufactured by Mitsubishi Rayon Co., Ltd., and the like. Moreover, it is also possible to use what contains the (meth) acrylic-type resin which has a lactone ring structure. Examples of the (meth) acrylic resin having a lactone ring structure include JP 2000-230016, JP 2001-151814, JP 2002-120326, JP 2002-254544, and JP 2005. Examples thereof include those described in Japanese Patent No. 146084 and Japanese Patent Application Laid-Open No. 2006-171464.

  The thickness of the transparent protective film is not particularly limited, but is generally about 1 to 500 μm and 10 to 300 μm from the viewpoint of workability such as strength and handleability, and thin layer properties. Preferably, it is 20-200 micrometers, It is more preferable that it is 30-100 micrometers.

  The transparent protective film may be subjected to surface modification treatment in order to improve adhesiveness with the polarizer before applying the adhesive. Specific examples of the treatment include corona treatment, plasma treatment, flame treatment, ozone treatment, primer treatment, glow treatment, saponification treatment, and treatment with a coupling agent. Further, an antistatic layer can be appropriately formed.

  The adhesive used for laminating the polarizer and the transparent protective film is not particularly limited as long as it is optically transparent, and water-based, solvent-based, hot-melt-based, and radical-curing types are used.

  Examples of the radical curable adhesive include various active energy ray curable types such as an electron beam curable type and an ultraviolet curable type, and a thermosetting type. Among these, an active energy ray curable type that can be cured in a short time is preferable, and an ultraviolet curable type is more preferable.

  Examples of aqueous adhesives include PVA adhesives, gelatin adhesives, vinyl latex adhesives, polyurethane adhesives, isocyanate adhesives, polyester adhesives, and epoxy adhesives. The adhesive may contain various crosslinking agents. In addition, a stabilizer such as a catalyst, a coupling agent, various tackifiers, an ultraviolet absorber, an antioxidant, a heat stabilizer, and a hydrolysis stabilizer can be added to the adhesive. Among these, a PVA adhesive is preferable.

  The adhesive further includes a coupling agent such as a silane coupling agent and a titanium coupling agent, various tackifiers, an ultraviolet absorber, an antioxidant, a heat stabilizer, a stabilizer such as a hydrolysis stabilizer, and the like. Can also be blended.

  Application | coating of the said adhesive agent may be performed to whichever side of the said polarizer and a transparent protective film, and may be performed to both. The application operation is not particularly limited, and various means such as a roll method, a spray method, and an immersion method can be employed. Moreover, you may provide an undercoat layer, an easily bonding process layer, etc. between the said adhesive bond layer, a transparent protective film, or a polarizer.

  Although the thickness of the adhesive bond layer formed with the said adhesive agent etc. is not specifically limited, It is preferable that it is about 10-300 nm. The thickness of the adhesive layer is more preferably from 10 to 200 nm, and even more preferably from 20 to 150 nm, from the viewpoint of obtaining a uniform in-plane thickness and sufficient adhesive strength.

  Moreover, as a polarizing plate, the polarizing plate of the laminated structure which laminated | stacked various optical layers on the surface which does not adhere | attach the polarizer of the said transparent protective film can also be illustrated. The optical layer is not particularly limited. For example, hard coating treatment, antireflection treatment, antisticking, surface treatment for diffusion or antiglare, or alignment liquid crystal for the purpose of viewing angle compensation, etc. A method of laminating layers is mentioned. Further, one or two optical films are used for forming a liquid crystal display device such as a reflection plate, a semi-transmission plate, a retardation plate (including a wave plate (λ plate) such as 1/2 or 1/4). The thing stuck together is also mentioned.

  An example of the optical film laminated on the polarizer is a retardation plate. Examples of the retardation plate include a birefringent film formed by uniaxially or biaxially stretching a polymer material, a liquid crystal polymer alignment film, and a liquid crystal polymer alignment layer supported by a film. The stretching treatment can be performed by, for example, a roll stretching method, a long gap stretching method, a tenter stretching method, a tubular stretching method, or the like. In the case of uniaxial stretching, the stretching ratio is generally about 1.1 to 3 times. The thickness of the retardation plate is not particularly limited, but is generally 10 to 200 μm, preferably 20 to 100 μm.

  Examples of the polymer material include polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, polysulfone, polyethylene terephthalate, polyethylene naphthalate, and polyethersulfone. , Polyphenylene sulfide, polyphenylene oxide, polyallylsulfone, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose polymer, or binary, ternary copolymers, graft copolymers, blends, etc. Is mentioned. These polymer materials become oriented products (stretched films) by stretching or the like.

  The retardation plate may have an appropriate retardation according to the purpose of use, such as those for the purpose of compensating for various wavelength plates and birefringence of liquid crystal layers and compensation of viewing angle, etc. These may also be ones in which optical characteristics such as retardation are controlled by laminating the retardation plates.

  Further, when various optical layers are formed on the polarizing plate, they can be laminated via an adhesive layer. The pressure-sensitive adhesive layer at this time is not particularly limited, and a known pressure-sensitive adhesive layer used in an image display device such as a liquid crystal display device can be used.

(2) Release film Examples of the release film include plastic films, rubber sheets, paper, cloth, non-woven fabrics, nets, foam sheets, metal foils, and suitable thin leaves such as laminates thereof.

  The plastic film is not particularly limited, but for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film. , Polyurethane film, ethylene-vinyl acetate copolymer film, and the like.

  Although the thickness of the said peeling film is not specifically limited, Usually, it is about 5-200 micrometers, and it is preferable that it is about 5-100 micrometers.

  For the release film, silicone, fluorine, long chain alkyl or fatty acid amide release agent, release by silica powder, etc., and antifouling treatment, coating type, kneading type, if necessary Further, an antistatic treatment such as a vapor deposition type can also be performed. In particular, the release property can be further improved by appropriately performing a release treatment such as silicone treatment, long-chain alkyl treatment, fluorine treatment on the surface of the release film.

  The said peeling film is laminated | stacked on an optical film through an adhesive layer.

  The pressure-sensitive adhesive layer can be formed of an appropriate pressure-sensitive adhesive according to the prior art such as acrylic, silicone, polyester, polyurethane, polyether, polyamide, fluorine, and rubber. This adhesive has the following features: prevention of foaming and peeling phenomenon due to moisture absorption, deterioration of optical properties due to thermal expansion differences, prevention of warping of liquid crystal cells, and formation of a high-quality and durable image display device. In addition, it is preferable that the pressure-sensitive adhesive layer has a low moisture absorption rate and excellent heat resistance, and further, it does not require a high-temperature process during curing and drying from the viewpoint of preventing changes in optical properties such as a polarizing plate. There are preferred ones that do not require a long curing process or drying time. From such a viewpoint, an acrylic pressure-sensitive adhesive is preferably used for the polarizing plate and the optical film. Further, fine particles may be added to the pressure-sensitive adhesive to form a pressure-sensitive adhesive layer that exhibits light diffusibility.

  Although it does not specifically limit as thickness after drying of an adhesive layer which consists of such an adhesive, Generally it is about 1-500 micrometers, 5-200 micrometers is preferable, and it is more preferable that it is 10-100 micrometers. .

(3) Surface protective film A surface protective film is formed on the surface of the optical film opposite to the surface provided with the release film for the purpose of preventing scratches and preventing contamination. As a surface protective film, the thing similar to the above-mentioned peeling film can be mentioned, for example.

  Although the thickness of the said surface protection film is not specifically limited, Usually, it is about 5-200 micrometers, and it is preferable that it is about 5-100 micrometers.

  The surface protective film is preferably laminated on the optical film via an adhesive layer. The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited, and a known pressure-sensitive adhesive used in an image display device such as a liquid crystal display device can be used. For example, it can be used for laminating the release film. The pressure-sensitive adhesive can also be used for laminating the surface protective film.

  Although the manufacturing method of the laminated optical film of this invention includes the said cutting process, it can also include other processes suitably. Examples of other steps include a step of peeling a laminated optical film composed of an adhesive, an optical film, and a surface protective film from the release film.

  The laminated optical film obtained by the method for producing a laminated optical film of the present invention includes at least an adhesive layer, an optical film, and a surface protective film. Moreover, when it is a layer structure as shown in FIG.1 (b), it becomes a layer structure which consists of the adhesive layer 14 / optical film 13 / adhesive layer 12 / surface protection film 11. FIG. When the optical film is used, the pressure-sensitive adhesive layer 12 / surface protective film 11 is peeled off.

  The laminated optical film obtained by the method for producing a laminated optical film of the present invention can be preferably used for forming various optical display devices such as a liquid crystal display device. The liquid crystal display device can be formed according to the conventional method. That is, the liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell (corresponding to an optical display unit), an optical film, and an illumination system as necessary, and incorporating a drive circuit. There is no particular limitation except that the optical film according to the present invention is used, and the conventional method can be applied. As the liquid crystal cell, any type of liquid crystal cell such as a TN type, STN type, or π type can be used.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples.

Example 1
A polarizing plate (trade name: NTB-VFCMEQ-ST06, thickness: 166 μm, manufactured by Nitto Denko Corporation) having a TAC film as a transparent protective film on both surfaces of the polarizer was prepared. A release film (PET film, thickness: 38 μm) is laminated on one surface of the polarizing plate via an adhesive layer (thickness: 23 μm), and an adhesive layer (thickness: 23 μm) is laminated on the opposite surface. A surface protective film (PET film, thickness: 38 μm) was laminated to prepare a laminate (total thickness: 227 μm).

  The obtained laminate was half cut using the cutting device 5 shown in FIG. 2 leaving the release film. Moreover, the cutting blade used in the manufacturing apparatus 5 was a round blade with an outer diameter size of 200 mm, a cutting edge of both edges, and a cutting edge angle of 20 °. The round blade is rotationally driven in the same direction as the moving direction (forward direction), the rotational speed is 720 mm / s, the moving speed is 800 mm / s, and the ratio of the rotational speed to the moving speed of the rotary blade to be cut. Was 90%. The floating of the surface protective film of the cut laminate was visually evaluated. The float of the surface protective film was less than 0.5 mm, and there was no problem with delamination, scuffing and lack of glue on the polarizing plate.

  In addition, as an adhesive layer used for the said laminated body, the adhesive layer as described in this specification can be used suitably, and even if it uses any adhesive layer, it confirms that the same result is obtained. did.

Examples 2-4
A laminate was formed in the same manner as in Example 1 except that the rotating direction, moving speed, and rotating speed of the rotary blade were changed as shown in Table 1. The floating of the surface protective film of the cut laminate was visually evaluated. The float of the surface protective film was less than 0.5 mm, and there was no problem with delamination, scuffing and lack of glue on the polarizing plate.

Comparative Examples 1-3
A laminate was formed in the same manner as in Example 1 except that the rotating direction, moving speed, and rotating speed of the rotary blade were changed as shown in Table 1. The floating of the surface protective film of the cut laminate was visually evaluated. The float of the surface protective film was 0.5 to 1.5 mm, and the float of the surface protective film was generated.

Comparative Example 4
A laminate was formed in the same manner as in Example 1 except that the rotary blade was fixed without rotating. The floating of the surface protective film of the cut laminate was visually evaluated. The float of the surface protective film was 1 to 1.5 mm, and the float of the surface protective film was generated.

In Table 1 above, “forward direction” means that the rotational direction of the rotary blade rotates in the same direction as the moving direction (the state shown in FIG. 1A), and “reverse direction” means that the rotary blade The rotation direction of the rotation of the rotary blade is in the direction opposite to the movement direction, and “fixed” indicates that the rotation of the rotary blade is stopped and the rotation is performed.

  In addition, regarding the evaluation of the float of the surface protective film, the case where the float of the surface protective film was less than 0.5 mm was “◯”, and the case where the float of the surface protective film was 0.5 mm or more was “x”.

  As is clear from Table 1, by cutting so that the ratio of the rotational speed to the moving speed of the rotationally driven cutting blade is 90% or more, the surface protective film can be prevented from floating, and the half-cut can be cut very well. I confirmed that.

DESCRIPTION OF SYMBOLS 1 Laminate 11 Surface protection film 12 Adhesive layer 13 Optical film 14 Adhesive layer 15 Release film 2 Cutting blade (round blade)
21 Cutting blade edge 3 Cutting blade moving direction 4 Cutting blade rotation direction 5 Cutting device 6 Moving mechanism 7 Cutting backing plate 8 Clamping means M Cutting moving direction W Width direction of the long laminate L L of the long laminate Longitudinal direction

Claims (4)

A method for producing a laminated optical film comprising a step of cutting a laminate in which a release film, an adhesive layer, an optical film, and a surface protective film are laminated in this order, leaving the release film,
The step of cutting is performed by moving a rotating cutting blade,
The rotating direction of the rotating cutting blade is the same direction as the moving direction of the cutting blade, and the ratio (B / A × 100) of the rotating speed B to the moving speed A of the rotating cutting blade is 90% or more. A method for producing a laminated optical film, wherein   The method for producing a laminated optical film according to claim 1, wherein the surface protective film is laminated on the optical film via an adhesive layer.   The method for producing a laminated optical film according to claim 1, wherein the optical film is a polarizing plate having a polarizer and a transparent protective film laminated on at least one surface of the polarizer.   The said polarizing plate is a elongate polarizing plate, Comprising: The said laminated body is cut | disconnected in the width direction of this elongate polarizing plate, The manufacturing method of the laminated optical film of Claim 3 characterized by the above-mentioned.