JP6556008B2 - Inspection method for long polarizers - Google Patents

Description

  The present invention relates to an inspection method for a long polarizer. More specifically, the present invention relates to a method for inspecting a long polarizer having non-polarizing portions arranged in a predetermined pattern.

  Some image display devices such as mobile phones and notebook personal computers (PCs) are equipped with internal electronic components such as cameras. Various studies have been made for the purpose of improving the camera performance and the like of such an image display device (for example, Patent Documents 1 to 7). However, with the rapid spread of smartphones and touch panel type information processing devices, further improvements in camera performance and the like are desired. Further, in order to cope with diversification and high functionality of the shape of the image display device, there is a demand for a polarizing plate partially having polarization performance. In order to realize these demands industrially and commercially, it is desired to manufacture an image display device and / or its components at an acceptable cost. Matters are left behind.

JP 2011-81315 A JP 2007-241314 A US Patent Application Publication No. 2004/0212555 Korean Published Patent No. 10-2012-0118205 Korean Patent No. 10-1293210 JP 2012-137738 A US Patent Application Publication No. 2014/0118826

  The present invention has been made to solve the above-described conventional problems, and a main object of the present invention is to lengthen a polarizer that can realize multi-function and high-functionality of an electronic device and has no variation in quality. An object of the present invention is to provide an inspection method capable of inspecting the long polarizer with high efficiency and high accuracy when manufacturing it into a scale.

The inspection method for a long polarizer having a non-polarizing part according to the present invention is a method of inspecting a long polarizer while conveying a long polarizer having a non-polarizing part arranged at predetermined intervals in the longitudinal direction and the width direction. Is a method for inspecting a cylindrical polarizer, wherein the imaging unit is positioned in the width direction with reference to the position of one of the non-polarizing units arranged in the same row in the width direction, and the imaging unit And photographing the non-polarization part arranged in the same row as the reference non-polarization part.
In one embodiment, the imaging unit is positioned in the width direction with reference to the position of the non-polarization unit located on the outermost side in the width direction.
According to another situation of this invention, the manufacturing method of the elongate polarizer which has a non-polarizing part is provided. This manufacturing method includes forming a non-polarizing portion in a long polarizer and inspecting the non-polarizing portion by the inspection method.
In one embodiment, after the formation of the non-polarizing part, the non-polarizing part is inspected continuously.
In one embodiment, the non-polarizing part is formed by bringing a basic solution into contact with a polarizer.
In one embodiment, the basic solution is contacted in a state where the polarizer is protected by a protective material so that at least a part of the polarizer is exposed.
In one embodiment, the manufacturing method uses, as the protective material, a long surface protective film in which through holes are arranged at predetermined intervals in the long direction and the width direction, and the polarizer and the surface It includes a state of being protected by the surface protective film so that at least a part of the polarizer is exposed by pasting the protective film with a roll-to-roll.

  ADVANTAGE OF THE INVENTION According to this invention, the test | inspection method which test | inspects the elongate polarizer which has a non-polarizing part arrange | positioned at predetermined intervals in the elongate direction and the width direction is provided. In this method, the non-polarization part photographing camera is positioned and positioned with reference to one non-polarization part among the non-polarization parts arranged in a line in the width direction while conveying the long polarizer. The non-polarized part is photographed by the non-polarized part photographing camera. In many cases, the non-polarized portion may be displaced from the long polarizer due to the meandering of the long polarizer. Even if the non-polarization part is misaligned with respect to the optical element, the non-polarization part imaging camera can accurately capture the non-polarization part, and in-line inspection makes it highly efficient and accurate. The part can be inspected.

It is a schematic plan view explaining an example of the arrangement pattern of the non-polarization part in the polarizer used for the inspection method of the present invention. (A)-(d) is a figure explaining the test | inspection method of the polarizer by one Embodiment of this invention. It is a schematic perspective view explaining bonding of the polarizer and the 1st surface protection film in the manufacturing method of the polarizer by the embodiment of the present invention. It is the schematic explaining formation of the non-polarization part in the manufacturing method of the polarizer by embodiment of this invention. It is a schematic perspective view of the polarizer obtained by embodiment of this invention.

  Hereinafter, although embodiment of this invention is described, this invention is not limited to these embodiment.

A. Inspection method of polarizer The inspection method of the present invention is a method of inspecting a long polarizer having non-polarizing portions arranged at predetermined intervals in the longitudinal direction and the width direction. This includes photographing the non-polarization part with a photographing part (non-polarization part photographing camera) while transporting. In this specification, “long shape” means an elongated shape having a sufficiently long length with respect to the width. For example, an elongated shape having a length that is 10 times or more, preferably 20 times or more the width. Including.

  The arrangement pattern of the non-polarizing parts can be appropriately set according to the purpose. In the long polarizer, the arrangement pattern of the non-polarizing parts is that a plurality of non-polarizing part groups including a plurality of non-polarizing parts arranged in the width direction within a predetermined range in the long direction are arranged in the long direction. Thus, it can be configured as a set of columns of non-polarizing parts extending in the longitudinal direction. In addition, the non-polarizing unit is configured so that when the polarizer is cut into a predetermined size (for example, cut in the longitudinal direction and / or the width direction and punched out) in order to attach the polarizer to the image display device of a predetermined size. It may be arranged at a position corresponding to the camera unit. In one embodiment, the non-polarizing portions are arranged at substantially equal intervals in both the longitudinal direction and the width direction. Note that “substantially equidistant in both the longitudinal direction and the width direction” means that the spacing in the longitudinal direction is equal and the spacing in the width direction is equal. The interval in the scale direction and the interval in the width direction need not be equal. In another embodiment, the non-polarizing portions may be arranged at substantially equal intervals in the longitudinal direction and at different intervals in the width direction. When the non-polarizing portions are arranged at different intervals in the width direction, the intervals between adjacent non-polarizing portions may be all different, or only a part (the interval between specific adjacent non-polarizing portions) may be different. .

FIG. 1 is a schematic plan view for explaining an example of an arrangement pattern of non-polarizing parts in a polarizer used in the inspection method of the present invention. In the present specification, for convenience, the position of the non-polarizing portion 10 is represented by L _Y -W _X. L _Y means that the position of the non-polarizing portion is the Y-th position in the length direction from the front in the transport direction (the lower side of the paper), and W _X is the position of the non-polarizing portion at the maximum in the transport direction. This means that it is Xth in the width direction from the right side (left side of the page). Therefore, the position of the non-polarizing part located in the forefront of the long polarizer in the transport direction and on the rightmost side in the transport direction is L ₁ −W ₁ . _Also, a non-polarizing portion that belongs to non-polarizing unit belonging to L 1 -W ₁ in the width direction same row to row _{L 1,} their position _is, L 1 from -W ₁ in _order, L ₁ -W _1, L 1 -W ₂ , L ₁ -W ₃ ,..., L ₁ -W _X , L ₁ -W _{X + 1} ,. _Furthermore, the L 1 -W ₁ and the elongated direction same rank belonging to the non-polarizing portion unpolarized portion belonging to columns _{W 1} a, their positions _from L 1 -W ₁ in _{order, L 1 -W 1, L 2} - W ₁ , L ₃ −W ₁ ,... L _Y −W _1, L _{Y + 1} −W ₁ ,. Further, the group of non-polarizing unit and the non-polarizing portion group L _Y belonging to row L _Y. In the present specification, “non-polarizing parts belonging to the same longitudinal direction” means non-polarizing parts arranged in the longitudinal direction within a predetermined range in the width direction. That is, the “non-polarizing portions belonging to the same longitudinal direction” do not necessarily have to be arranged in a straight line.

  In one embodiment, as shown in FIG. 1, the non-polarizing portion 10 has a straight line connecting adjacent non-polarizing portions in the longitudinal direction substantially parallel to the longitudinal direction, and a width. A straight line connecting adjacent non-polarizing portions in the direction is arranged so as to be substantially parallel to the width direction.

It goes without saying that the arrangement pattern of the non-polarizing portions is not limited to the illustrated example. For example, in the non-polarizing part 10, a straight line connecting the non-polarizing parts arranged in the longitudinal direction within a predetermined range in the width direction has a predetermined angle θ _L with respect to the longitudinal direction, and is adjacent in the width direction. The straight line connecting the non-polarizing portions to be arranged may be arranged so as to be substantially parallel to the width direction.

As described above, the non-polarizing portions may be arranged at different intervals in the width direction, but the interval between a pair of non-polarizing portions 10 adjacent in the width direction, that is, W _X and W _{X + 1} in the same row, Is preferably substantially the same in all rows. More specifically, it is preferable that the distance between L _Y −W _X / L _Y −W _{X + 1} and the distance between L _{Y + 1} −W _X / L _{Y + 1} −W _{X + 1} are substantially equal. In this way, it is possible to simplify the control of the non-polarization part photographing camera. Details will be described later.

  Any appropriate shape can be adopted as the planar view shape of the non-polarizing part depending on the purpose. For example, any appropriate shape can be adopted as the planar view shape of the non-polarizing part as long as it does not adversely affect the camera performance of the image display device using the polarizer. The non-polarizing portion in the illustrated example is circular, but may be formed in, for example, an elliptical shape, a square shape, a rectangular shape, a diamond shape, or the like.

  The transmittance of the non-polarizing part (for example, the transmittance measured with light having a wavelength of 550 nm at 23 ° C.) is preferably 50% or more, more preferably 60% or more, further preferably 75% or more, Particularly preferably, it is 90% or more. With such a transmittance, for example, when a polarizer is arranged so that the non-polarizing part corresponds to the camera part of the image display device, it is possible to prevent an adverse effect on the photographing performance of the camera.

  The non-polarizing part can be in any suitable form. In one embodiment, the non-polarizing part is a partially bleached decoloring part. The decolorization part is formed by, for example, laser irradiation or chemical treatment. In another embodiment, the non-polarizing part is a through hole. The through hole is formed by, for example, mechanical punching (for example, punching, engraving blade punching, plotter, water jet) or removal of a predetermined portion (for example, laser ablation or chemical dissolution).

  The inspection method of the present invention performs positioning in the width direction of the imaging unit with reference to the position of one non-polarizing unit among the non-polarizing units arranged in the same row in the width direction, and uses the imaging unit as a reference Imaging the non-polarizing part arranged in the same row as the non-polarizing part in the width direction. That is, for each non-polarizing part group (each row), the position of one non-polarizing part (hereinafter also referred to as a reference non-polarizing part) among the non-polarizing parts arranged in the same row in the width direction is used as a reference. The non-polarization part photographing camera is positioned, and the non-polarization part arranged in the width direction is photographed by the non-polarization part photographing camera. Hereinafter, the inspection method of the present invention will be described with reference to FIG.

First, as shown in FIG. 2A, an arbitrary appropriate camera 1 (hereinafter also referred to as a reference detection camera) is used to be placed in the forefront of the long polarizer 100 (that is, the non-polarization portion group L ₁ ). The position in the width direction of the reference non-polarizing part 10 ′ thus detected is detected. The detection of the reference non-polarization unit 10 ′ is performed while the long polarizer 100 is conveyed in the long direction (from the upper side to the lower side in FIG. 2). Note that FIG. 2 shows a scene in which the non-polarizing portion 10 meanders in the transport direction of the long polarizer 100 being transported.

The reference non-polarizing part 10 ′ is one of the non-polarizing parts arranged in the same row in the width direction. That is, each non-polarizing part group has a reference non-polarizing part 10 ′ which is one of the non-polarizing parts 10 arranged in the same row in the width direction. Preferably, the reference non-polarizing portions 10 ′ are arranged in the same column in the longitudinal direction. In FIG. 2 (a), the unpolarized portion located in tandem W ₁ at each of the non-polarizing portion group (row) is a reference non-polarizing portion 10 '. Preferably, as in the illustrated example, the non-polarizing unit 10 on the outermost side in the width direction (in the illustrated example, the rightmost side in the transport direction) is set as a reference non-polarizing unit 10 ′. If the outermost non-polarizing part in the width direction is the reference non-polarizing part 10 ', the space required for installing the reference detection camera 1 can be reduced.

The reference detection camera 1 is fixedly installed at a position where the reference non-polarization part 10 ′ can be detected on the upstream side in the longitudinal direction of the non-polarization part photographing camera. Even when a straight line connecting adjacent reference non-polarization parts 10 'in the long direction is not parallel to the long direction, or when the arrangement of the polarizer and / or the reference non-polarization part is meandering, the reference non-polarization part The detection range of the reference detection camera 1 is set so that 10 ′ can be detected without exception. Moreover, it is preferable that non-polarization parts other than the reference non-polarization part are outside the detection range of the reference detection camera 1. Sensing area of the reference sensing camera 1 is, for ^example, a 50cm ² ~500cm 2, preferably 200cm ² ~400cm ^2. Further, the detection area of the reference detection camera 1 is preferably 2 to 30 times, more preferably 20 to 30 times the area of the reference non-polarizing part 10 ′.

  Next, as shown in FIGS. 2B and 2C, the non-polarization part photographing camera 2 is positioned with reference to the reference non-polarization part 10 ′ detected by the reference detection camera 1. Preferably, the non-polarization part photographing camera 2 is positioned based on the position of the center or the center of gravity of the reference non-polarization part 10 '.

  The non-polarization part photographing camera 2 is installed on the downstream side in the longitudinal direction of the reference detection camera 1 and on the upper side in the thickness direction or the lower side in the thickness direction of the polarizer 100. Preferably, the non-polarizing parts constituting the non-polarizing part group are arranged in a straight line, and the non-polarizing part photographing camera 2 has a straight line connecting the non-polarizing parts constituting the non-polarizing part group (non-adjacent non-polarizing parts in the width direction). It is installed so that it can move in parallel with the straight line connecting the polarizing parts.

The non-polarization part photographing camera 2 has a function of photographing the non-polarization part. As long as it has such a function, the non-polarization part photographing camera 2 can take any appropriate form. Preferably, the non-polarization part photographing camera 2 photographs one non-polarization part group (that is, a plurality of the non-polarization parts arranged in the width direction) at a time. FIG. 2 shows an example in which the non-polarization parts belonging to the non-polarization part group L ₁ (row L ₁ ) are photographed at once by the non-polarization part photographing camera 2.

  The non-polarization part may be photographed by a plurality of non-polarization part photographing cameras 2, or the non-polarization part may be photographed by one non-polarization part photographing camera 2. In addition, one non-polarizing part imaging camera 2 may shoot one non-polarizing part or a plurality of non-polarizing parts. Preferably, the same number of non-polarization part photographing cameras 2 as the number of columns of non-polarization parts to be photographed are used, and one non-polarization part is obtained by one photographing with one non-polarization part photographing camera 2. Taken.

  In one embodiment, the non-polarization part photographing camera 2 photographs all the non-polarization parts belonging to the same row. That is, all the non-polarized parts including the reference non-polarized part are photographed. Such an embodiment may be employed when a non-polarizing part including a reference non-polarizing part is included in the final product. In another embodiment, as shown in the example, the non-polarization part photographing camera 2 photographs non-polarization parts other than the reference non-polarization part among the non-polarization parts belonging to the same row. Such an embodiment may be employed when the reference non-polarization part is not included in the final product, that is, when the reference non-polarization part is used only as a reference for positioning the non-polarization part photographing camera 2. .

The positioning of the non-polarization part photographing camera 2 is performed by detecting the non-polarization part group belonging to the same row as the reference non-polarization part 10 ′ after the reference non-polarization part 10 ′ is detected by the reference detection camera 1. This is performed until the shooting area of the camera 2 is reached. For example, (i) as shown in FIG. 2A, the reference detection camera 1 detects the position in the width direction of the reference non-polarizing portion 10 ′ located at the position L ₁ −W ₁ , and (ii) FIG. As shown in b), while the row L ₁ is moving forward, the non-polarization part photographing camera 2 moves in a direction parallel to the straight line connecting the non-polarization parts constituting the row L ₁ , and (iii) ) as shown in FIG. 2 (c), row L ₁ is, before reaching the non-polarizing portion photographing camera 2 below, the non-polarizing portion photographing camera 2, taking the unpolarized portion row L ₁ to the possible locations that are positioned, (iv) as shown in FIG. 2 (d), when the unpolarized portion of row L ₁ reaches the lower unpolarized portion photographing camera 2, the non-polarization section The photographing camera 2 photographs the non-polarized part. At this time, the non-polarization part photographing camera 2 is positioned with reference to the position (preferably, the position of the center or the center of gravity) of the reference non-polarization part 10 ′ detected by the reference detection camera 1. More specifically, the distance between the non-polarization part to be imaged and the reference non-polarization part 10 ′ can be known by measurement before inspection (before the polarizer is transported), and information on the distance and detection The photographing position of the non-polarizing part photographing camera 2 is determined from the position information in the width direction of the reference non-polarizing part 10 ′. According to such a method, even when the long polarizer to be conveyed meanders, the non-polarization part photographing camera 2 can be moved according to the degree of meandering, and the non-polarization part 10 can be reliably connected. You can shoot.

As described above, the interval between a pair of non-polarizing portions adjacent in the width direction, that is, the interval between W _X and W _{X + 1} in the same row is preferably substantially the same in all the rows. Thus, if the non-polarizing part is arranged, the interval between the non-polarizing part photographing cameras 2 installed in a plurality can be made constant, and the control of the non-polarizing part photographing camera 2 can be simplified. Can do.

  The photographing timing of the non-polarization part photographing camera 2 can be automated. The photographing timing of the non-polarization part photographing camera 2 can be set based on the distance between the reference detection camera 1 and the non-polarization part photographing camera 2 in the longitudinal direction. Further, the non-polarization part photographing camera 2 may be configured to detect the intrusion of the non-polarization part into the photographing range of the non-polarization part photographing camera 2 and to photograph the non-polarization part 10 instantaneously after the detection. .

  The control of the reference detection camera 1 and the non-polarization part photographing camera 2, that is, the position detection of the reference non-polarization part 10 ′, the movement of the non-polarization part photographing camera 2 according to the position detection, the non-polarization part photographing camera. Control such as photographing by 2 can be performed by any appropriate method.

  In the inspection method of the present invention, the non-polarized portion and the vicinity thereof are inspected by performing image processing on the image picked up by the non-polarized portion photographing camera 2 by any appropriate method. The inspection method of the present invention can inspect the appearance of the non-polarizing part and the vicinity thereof. For example, the shape of the non-polarizing part (for example, shape matching degree such as roundness, roughness of the contour, etc.), non-polarizing part The light transmission property, the presence / absence of foreign matter in the non-polarizing portion, etc. are inspected. Any appropriate camera can be adopted as the non-polarization part photographing camera 2 as long as it is a camera capable of the above inspection. As the non-polarization part photographing camera 2, it is preferable to use a high-precision and high-resolution camera. Such a camera usually has a narrow shooting range. In the present invention, by positioning the non-polarization part photographing camera 2 with reference to the reference non-polarization part 10 ′, the non-polarization part can be reliably secured even if the photographing range of the non-polarization part photographing camera 2 is narrow. Can be inspected.

  As described above, the imaging and inspection of the non-polarizing portion in the front row are completed. In the present invention, the position detection of the reference non-polarization part 10 ′, the movement of the non-polarization part photographing camera 2, the positioning of the non-polarization part photographing camera 2, and the photographing and inspection by the non-polarization part photographing camera 2 are performed as non-polarization. Repeatedly for each group (row), the non-polarized part is imaged and inspected.

  In the inspection method of the present invention, as described above, the non-polarization part photographing camera is movably installed, and one non-polarization part (reference non-polarization part) among the non-polarization parts arranged in the same row in the width direction. By positioning the non-polarization part photographing camera on the basis of the position of the non-polarization part photographing camera, even if the non-polarization part meanders with respect to the longitudinal direction of the long polarizer, Can accurately capture the non-polarized part. In addition, since the position detection of the reference non-polarization part and the movement of the camera for photographing the non-polarization part can be repeated continuously, the long polarizer can be inspected in-line. That is, according to the inspection method of the present invention, it is possible to inspect the non-polarizing part with high efficiency and high accuracy. In addition, in the method of detecting the position of the end of the long polarizer itself in the width direction (edge detection) and positioning the non-polarization part photographing camera based on the position, the position of the end in the width direction is not detected. The distance to the polarizing part cannot be constant, and the non-polarizing part photographing camera cannot accurately capture the non-polarizing part. For example, when a sawtooth-like spot occurs at the widthwise end of the long polarizer, the distance between the reference widthwise end and the non-polarizing part changes at the spot, so the non-polarizing part imaging The camera cannot be positioned accurately.

B. The manufacturing method of the elongate polarizer which has a non-polarization part The manufacturing method of the elongate polarizer which has the non-polarization part of this invention forms a non-polarization part in an elongate polarizer, and the said test | inspection Inspecting the non-polarizing part by the method.

B-1. Polarizer The polarizer is typically composed of a resin film containing a dichroic substance. Examples of the dichroic substance include iodine and organic dyes. These may be used alone or in combination of two or more. Preferably iodine is used.

  Arbitrary appropriate resin may be used as resin which forms the said resin film. Preferably, a polyvinyl alcohol resin is used. Examples of the polyvinyl alcohol resin include polyvinyl alcohol and ethylene-vinyl alcohol copolymer. Polyvinyl alcohol is obtained by saponifying polyvinyl acetate. An ethylene-vinyl alcohol copolymer can be obtained by saponifying an ethylene-vinyl acetate copolymer.

  The polarizer (excluding the non-polarized part) preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance (Ts) of the polarizer (excluding the non-polarized part) is preferably 39% or more, more preferably 39.5% or more, still more preferably 40% or more, and particularly preferably 40.5% or more. . The theoretical upper limit of the single transmittance is 50%, and the practical upper limit is 46%. Further, the single transmittance (Ts) is a Y value measured with a 2 degree visual field (C light source) of JIS Z8701 and corrected for visibility, for example, using a microspectroscopic system (Lambda Vision, LVmicro). Can be measured. The degree of polarization of the polarizer (excluding the non-polarized part) is preferably 99.9% or more, more preferably 99.93% or more, and further preferably 99.95% or more.

  The thickness of the polarizer can be set to any appropriate value. The thickness is preferably 30 μm or less, more preferably 25 μm or less, still more preferably 20 μm or less, and particularly preferably 10 μm or less. On the other hand, the thickness is preferably 0.5 μm or more, more preferably 1 μm or more.

  The absorption axis of the polarizer can be set in any appropriate direction depending on the purpose. The direction of the absorption axis may be, for example, the long direction or the width direction. For example, a polarizer having an absorption axis in the longitudinal direction has an advantage of excellent manufacturing efficiency. A polarizer having an absorption axis in the width direction has an advantage that, for example, a retardation film having a slow axis in the longitudinal direction can be laminated with a roll-to-roll. In one embodiment, the absorption axis is substantially parallel to the longitudinal direction or the width direction, and both ends of the polarizer in the width direction are slit in parallel to the longitudinal direction. According to such a configuration, it is possible to easily produce a plurality of polarizers that can be cut based on the edge of the polarizer, have a non-polarizing portion at a desired position, and have an absorption axis in an appropriate direction. Can do. In addition, the absorption axis of a polarizer can respond | correspond to the extending | stretching direction in the below-mentioned extending | stretching process.

  The polarizer is typically obtained by subjecting the resin film to various treatments such as swelling treatment, stretching treatment, dyeing treatment with the dichroic substance, crosslinking treatment, washing treatment, and drying treatment. When performing various treatments, the resin film may be a resin layer formed on a substrate. The formation of the non-polarizing part can also be performed during the manufacturing process of the polarizer.

B-2. Formation of non-polarizing part Preferably, a non-polarizing part is a decoloring part. According to such a configuration, cracks and delamination are mechanically compared (for example, by a method of mechanical engraving using a sculpture blade punching, a plotter, a water jet, or the like), compared to a case where a through hole is formed. Quality problems such as (delamination) and paste sticking are avoided. The decolorization part is preferably formed by bringing a basic solution into contact with a desired position of a polarizer (resin film containing a dichroic substance). The non-polarizing part formed by such a method can be a low-density part having a lower dichroic substance content than other parts (non-contact parts). Since the content of the dichroic substance itself is low in the low-concentration part, the transparency of the non-polarizing part is maintained better than when the dichroic substance is decomposed by laser light or the like to form the decolored part. Is done.

  The content of the dichroic substance in the low concentration part is preferably 1.0% by weight or less, more preferably 0.5% by weight or less, and still more preferably 0.2% by weight or less. The lower limit value of the content of the dichroic substance in the low concentration part is usually not more than the detection limit value. The difference between the content of the dichroic substance in the other part and the content of the dichroic substance in the low concentration part is preferably 0.5% by weight or more, more preferably 1% by weight or more. When iodine is used as the dichroic substance, the iodine content is obtained, for example, from a calibration curve prepared in advance using a standard sample from the X-ray intensity measured by fluorescent X-ray analysis.

  Any appropriate compound can be used as the basic compound contained in the basic solution. Examples of the basic compound include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, alkaline earth metal hydroxides such as calcium hydroxide, and inorganic alkali metal salts such as sodium carbonate. , Organic alkali metal salts such as sodium acetate, aqueous ammonia and the like. Among these, an alkali metal and / or alkaline earth metal hydroxide is preferably used, and sodium hydroxide, potassium hydroxide, and lithium hydroxide are more preferably used. A dichroic substance can be ionized efficiently, and a decoloring part can be formed more simply. These basic compounds may be used alone or in combination of two or more.

  As the solvent for the basic solution, water and alcohol are preferably used. The density | concentration of a basic solution is 0.01N-5N, for example, Preferably it is 0.05N-3N, More preferably, it is 0.1N-2.5N. The liquid temperature of the basic solution is, for example, 20 ° C to 50 ° C. The contact time of the basic solution can be set according to the thickness of the polarizer and the type and concentration of the basic compound contained in the basic solution. The contact time is, for example, 5 seconds to 30 minutes, preferably 5 seconds to 5 minutes.

  Arbitrary appropriate methods can be employ | adopted as a contact method of a basic solution. For example, a method of dropping, coating, and spraying a basic solution with respect to the polarizer, and a method of immersing the polarizer in the basic solution can be mentioned. When the basic solution is contacted, the polarizer may be protected with any appropriate protective material so that the basic solution does not contact other than the desired site. As such a protective material, for example, a protective film or a surface protective film is used. The protective film can be used as it is as a protective film for a polarizer. The surface protective film is temporarily used when manufacturing the polarizer. Since the surface protective film is removed from the polarizer at any appropriate timing, the surface protective film is typically bonded to the polarizer via an adhesive layer. Another specific example of the protective material is a photoresist. Moreover, the base material used in the manufacturing process of the said polarizer can also be used as a protective material.

  Preferably, at the time of contact with the basic solution, the surface of the polarizer is coated with a surface protective film so that at least a part of the surface is exposed. The polarizer having the arrangement pattern of the non-polarizing portion as shown in the illustrated example has a surface protective film in which a small circular through hole corresponding to the desired non-polarizing portion size is formed at a position corresponding to the arrangement pattern. A polarizing film laminate is prepared by bonding to one side of the substrate, and a basic solution is brought into contact therewith. In that case, it is preferable that the other side of the polarizer (the side on which the surface protective film having the through holes is not disposed) is also protected. The bonding of the protective film and the surface protective film is preferably performed by roll-to-roll as shown in FIG. In this specification, “roll-to-roll” refers to laminating a roll film while aligning each other in the longitudinal direction.

  FIG. 4 is a partial cross-sectional view of a polarizing film laminate according to one embodiment of the present invention. The polarizing film laminate 101 includes a polarizer 100 and a first surface protection film 20 disposed on one surface side (upper surface side in the illustrated example) of the polarizer 100, and the other surface side (lower surface in the illustrated example). A protective film 30 and a second surface protective film 40 disposed on the side). The polarizing film laminate 101 has exposed portions 11, 11,... Where the polarizer 100 is exposed on one surface side (the upper surface side in the illustrated example). The exposed portion 11 is provided by forming a through hole 21 in the first surface protective film 20.

  Examples of the material for forming the surface protective film include ester resins such as polyethylene terephthalate resins, cycloolefin resins such as norbornene resins, olefin resins such as polyethylene and polypropylene, polyamide resins, and polycarbonate resins. Polymer resin etc. are mentioned. Preference is given to ester resins (especially polyethylene terephthalate resins). This is because the elastic modulus is sufficiently high and, for example, deformation of the through-hole hardly occurs even when tension is applied during conveyance and / or bonding. The thickness of the surface protective film is typically 20 μm to 250 μm, preferably 30 μm to 150 μm.

  The first surface protective film has through holes arranged in a predetermined pattern. The position of the through hole corresponds to the position where the non-polarizing part is formed. The shape of the through hole corresponds to the desired shape of the non-polarizing part. The through hole is formed by, for example, mechanical punching (for example, punching, engraving blade punching, plotter, water jet) or removal of a predetermined portion of the film (for example, laser ablation or chemical dissolution).

  The surface protective film is peeled and removed at any appropriate timing after the contact with the basic solution, for example.

  Examples of the material for forming the protective film include cellulose resins such as diacetyl cellulose and triacetyl cellulose, olefin resins such as (meth) acrylic resins, cycloolefin resins and polypropylene, and ester resins such as polyethylene terephthalate resins. Examples thereof include resins, polyamide resins, polycarbonate resins, and copolymer resins thereof. The thickness of the protective film is preferably 10 μm to 100 μm.

  The surface of the protective film where the polarizer is not laminated may be subjected to a treatment for the purpose of a hard coat layer, antireflection treatment, diffusion or antiglare as a surface treatment layer. The protective film is typically bonded to the polarizer via an adhesive layer.

  In one embodiment, the basic solution is removed from the polarizer by any suitable means after contact with the polarizer. According to such embodiment, the fall of the transmittance | permeability of the non-polarizing part accompanying use of a polarizer can be prevented more reliably, for example. Specific examples of the method for removing the basic solution include washing, wiping removal with a waste cloth, suction removal, natural drying, heat drying, air drying, vacuum drying, and the like. Preferably the basic solution is washed. Examples of the cleaning liquid used for cleaning include water (pure water), alcohols such as methanol and ethanol, and mixed solvents thereof. Preferably, water is used. The number of washings is not particularly limited, and may be performed a plurality of times. When the basic solution is removed by drying, the drying temperature is, for example, 20 ° C to 100 ° C.

  Preferably, after the contact with the basic solution, alkali metal and / or alkaline earth metal contained in the resin film is reduced in the contact portion where the basic solution is contacted. By reducing the alkali metal and / or alkaline earth metal, a non-polarizing part having excellent dimensional stability can be obtained. Specifically, even in a humid environment, the shape of the non-polarizing part formed by contact with the basic solution can be maintained as it is.

  By contacting with the basic solution, alkali metal and / or alkaline earth metal hydroxide may remain in the contact portion. In addition, by contacting the basic solution, a metal salt (for example, borate) of an alkali metal and / or an alkaline earth metal can be generated at the contact portion. These can generate hydroxide ions, and the generated hydroxide ions act (decompose and reduce) on the dichroic substance (for example, iodine complex) existing around the contact area to widen the non-polarized region. obtain. Therefore, by reducing the alkali metal and / or alkaline earth metal salt, it is considered that the non-polarized region can be prevented from spreading over time and the desired non-polarized part shape can be maintained.

  The non-polarizing part preferably has an alkali metal and / or alkaline earth metal content of 3.6% by weight or less, more preferably 2.5% by weight or less, and still more preferably 1.0% by weight. % Or less, particularly preferably 0.5% by weight or less. The content of alkali metal and / or alkaline earth metal can be determined, for example, from a calibration curve prepared in advance using a standard sample from the X-ray intensity measured by fluorescent X-ray analysis.

  As the method of reducing, preferably, a method of bringing an acidic solution into contact with a contact portion with a basic solution is used. According to such a method, the alkali metal and / or alkaline earth metal can be efficiently transferred to the acidic solution, and the content thereof can be reduced. The contact with the acidic solution may be performed after the basic solution is removed or may be performed without removing the basic solution.

  Any appropriate acidic compound can be used as the acidic compound contained in the acidic solution. Examples of the acidic compound include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and hydrogen fluoride, and organic acids such as formic acid, oxalic acid, citric acid, acetic acid, and benzoic acid. Among these, the acidic compound contained in the acidic solution is preferably an inorganic acid, and more preferably hydrochloric acid, sulfuric acid, or nitric acid. These acidic compounds may be used alone or in combination of two or more.

  As the solvent of the acidic solution, water and alcohol are preferably used. The density | concentration of an acidic solution is 0.01N-5N, for example, Preferably it is 0.05N-3N, More preferably, it is 0.1N-2.5N. The liquid temperature of the acidic solution is, for example, 20 ° C to 50 ° C. The contact time of the acidic solution is, for example, 5 seconds to 5 minutes. In addition, the contact method of an acidic solution can employ | adopt the method similar to the contact method of the said basic solution. The acidic solution can also be removed from the polarizer. As a method for removing the acidic solution, a method similar to the method for removing the basic solution may be employed.

B-3. Inspection of non-polarizing part After the non-polarizing part is formed, the non-polarizing part is inspected by the above inspection method. When performing the inspection, the surface protective film may be laminated on the polarizer, or the surface protective film may be peeled off. Moreover, when inspecting, it is preferable that the polarizer is in a state of a polarizing plate with a protective film bonded to at least one side.

  In one embodiment, after the non-polarizing part is formed, the non-polarizing part is inspected continuously. Specifically, after forming the non-polarizing part, the non-polarizing part is inspected without winding up the polarizer. For example, after forming a non-polarization part with respect to a polarizing film laminated body as shown in FIG. 4, it uses for the inspection process of a non-polarization part as it is. Thus, by continuously inspecting after formation of the non-polarizing part (specifically, by determining whether the size of the formed non-polarizing part is larger or smaller than a predetermined size), for example, Problems in the contact step with the basic solution (for example, the state of through-holes in the surface protective film, the immersion state of the basic solution) can be detected at an early stage.

  After the inspection, the polarizer can be provided practically as a polarizing plate. In one embodiment, the polarizing plate has an adhesive layer for bonding to another member. Preferably, a separator is temporarily attached to the surface of the pressure-sensitive adhesive layer, so that the pressure-sensitive adhesive layer is protected until actual use, and a roll can be formed as shown in FIG.

  The polarizer obtained by the production method of the present invention is suitably used for an image display device with a camera (liquid crystal display device, organic EL device) such as a mobile phone such as a smartphone, a notebook PC, or a tablet PC.

10 non-polarizing part 10 'reference non-polarizing part
100 Polarizer

Claims (7)

A method of inspecting a long polarizer while conveying a long polarizer having non-polarizing portions arranged at predetermined intervals in the long direction and the width direction,
The imaging unit is positioned in the width direction with reference to the position of one of the non-polarizing units arranged in the same direction in the width direction, and the imaging unit performs the same alignment in the width direction as the reference non-polarizing unit. Photographing the non-polarized part arranged in
A method for inspecting a long polarizer having a non-polarizing part.   The inspection method for a long polarizer having a non-polarizing part according to claim 1, wherein the photographing part is positioned in the width direction with reference to the position of the non-polarizing part located on the outermost side in the width direction. The production of a long polarizer having a non-polarizing part, comprising forming a non-polarizing part on a long polarizer and inspecting the non-polarizing part by the inspection method according to claim 1. Method.   The manufacturing method of Claim 3 which inspects the said non-polarizing part continuously after formation of the said non-polarizing part.   The manufacturing method of Claim 3 or 4 which makes a basic solution contact a polarizer and forms the said non-polarizing part.   The manufacturing method according to claim 5, wherein the basic solution is contacted in a state where the polarizer is protected by a protective material so that at least a part of the polarizer is exposed. As the protective material, using a long surface protective film in which through holes are arranged at predetermined intervals in the long direction and the width direction,
Including bonding the polarizer and the surface protective film by roll-to-roll, thereby protecting the polarizer and the surface protective film so that at least a part of the polarizer is exposed.
The manufacturing method according to claim 6.

Images