KR101856399B1 - Method for producing polarizer having non-polarizing part - Google Patents

Abstract

There is provided a manufacturing method capable of efficiently manufacturing a polarizer having a high-quality non-light-emitting portion. A method for producing a polarizer having a non-light-deflecting portion of the present invention includes a polarizer and a surface protective film disposed on one surface side of the polarizer, wherein the long side of the long polarizing film laminate having an exposed portion on which the polarizer is exposed And a step of immersing the polarizing film laminate in a basic solution after the liquid contacting step. In one embodiment, the liquid is the same basic solution as the basic solution.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a polarizer having a non-

The present invention relates to a method for producing a polarizer having a non-light-emitting portion.

BACKGROUND ART [0002] An image display device such as a cellular phone or a notebook type personal computer (PC) has an internal electronic component such as a camera mounted thereon. For the purpose of improving the camera performance and the like of such an image display apparatus, various studies have been made (for example, Patent Documents 1 to 6). However, due to the rapid spread of smart phones and touch panel type information processing devices, further improvement in camera performance and the like is demanded. In addition, in order to cope with the diversification and high functionality of the image display apparatus, a polarizing plate having a partial polarization performance is required. In order to industrially and commercially realize these demands, it is desired to manufacture image display devices and / or parts thereof at an allowable expense, and various considerations remain in order to establish such a technology.

Japanese Laid-Open Patent Publication No. 2011-81315 Japanese Patent Application Laid-Open No. 2007-241314 U.S. Patent Application Publication No. 2004/0212555 Korean Patent Laid-Open No. 10-2012-0118205 Korean Patent Publication No. 10-1293210 Japanese Laid-Open Patent Publication No. 2012-137738

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional problems, and its main object is to provide a manufacturing method capable of efficiently manufacturing a polarizer having a high-quality non-light-emitting portion.

A method for producing a polarizer having a non-light-deflecting portion of the present invention includes a polarizer and a surface protective film disposed on one surface side of the polarizer, wherein the long side of the long polarizing film laminate having an exposed portion on which the polarizer is exposed And a step of immersing the polarizing film laminate in a basic solution after the liquid contacting step.

In one embodiment, the liquid is the same basic solution as the basic solution.

In one embodiment, the liquid is brought into contact with the one surface side of the polarizing film laminate by using a nozzle for jetting the liquid.

In one embodiment, the liquid is injected linearly onto the exposed portion.

In one embodiment, the exposed portion is arranged in a pattern having a repeating unit, and the liquid is injected linearly onto the exposed portion for each of the repeating units.

A polarizing film and a surface protective film disposed on the one surface side of the polarizer, and using a polarizing film laminate having an exposed portion where the polarizer is exposed on one side thereof, May be performed. In addition, since each of the steps can be carried out continuously and the production efficiency is excellent, immersion into a treatment liquid using a laminate of a long-sized image is carried out as a wet treatment. When the polarizing film laminate having the exposed portion is used for immersion, when the polarizing film laminate is transported into the treatment liquid, air may be introduced into the exposed portion and bubble inclusion may occur. The bubbles received in the exposed portion can be attached to the bottom portion or the wall surface of the exposed portion. The portion to which bubbles are attached can not sufficiently contact with the treatment liquid by the subsequent immersion treatment, so that the effect of immersion in the treatment liquid can not be sufficiently obtained, and the quality of the obtained polarizer may be lowered. Thus, a method for producing a high-quality polarizer while improving the manufacturing efficiency has been desired in a manufacturing method of immersing a polarizing film laminate having an exposed portion.

According to the production method of the present invention, since the bottom portion or the wall surface of the exposed portion can be wetted by bringing the liquid into contact with the polarizing film laminate before immersing the polarizing film laminate in the basic solution, the inclusion of bubbles can be suppressed. As a result, even when the immersion treatment is performed using the polarizing film laminate having the exposed portion, it is possible to efficiently manufacture a polarizer having a high-quality non-light-emitting portion. Conventionally, when the production efficiency of a polarizer having a non-light-emitting portion is improved by using immersion in a basic solution, the quality may be lowered due to defective discoloration due to inclusion of bubbles. However, in the manufacturing method of the present invention, since the bubble itself is suppressed, a polarizer having a high-quality non-light-emitting portion can be efficiently produced.

1 is a schematic cross-sectional view of a polarizing film laminate used in an embodiment of the present invention.
2 is a schematic perspective view of a polarizing film laminate used in an embodiment of the present invention.
3 is a schematic perspective view explaining the bonding of the surface protective film and the polarizing plate in the polarizing plate manufacturing method according to the embodiment of the present invention.
Fig. 4 is a schematic view showing a liquid contact process with the exposed portion of the polarizing film laminate according to one embodiment of the present invention and a process of immersing the polarizing film laminate into a basic solution; Fig.
Fig. 5 is a schematic partial enlarged view showing a liquid contact process to the exposed portion of the polarizing film laminate of Fig. 4; Fig.
Fig. 6 is a schematic partial enlarged view showing a liquid contact process to the exposed portion of the polarizing film laminate of Fig. 4; Fig.
7 is a schematic partial enlarged view showing a liquid contact process to an exposed portion of a polarizing film laminate according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

A method for producing a polarizer having a non-light-deflecting portion of the present invention includes a polarizer and a surface protective film disposed on one surface side of the polarizer, wherein the long side of the long polarizing film laminate having an exposed portion on which the polarizer is exposed And a step of immersing the polarizing film laminate in a basic solution after the liquid contacting step. When immersing is carried out using a polarizing film laminate having an exposed portion, when the polarizing film laminate is transported into the basic solution, air may be introduced into the exposed portion and bubble inclusion may occur. Since the portion to which the bubble is attached can not sufficiently contact with the basic solution, defective discoloration may occur. As a result, the characteristics such as the transmittance of the non-light-emitting portion become insufficient and the quality may deteriorate. On the other hand, when a liquid is brought into contact with the side having the exposed portion of the polarizing film laminate before the polarizing film laminate is immersed in the basic solution, the inclusion of bubbles is suppressed, and a polarizer having a high quality non- The polarizer before forming the non-light-deflected portion is strictly an intermediate of the polarizer having the non-light-deflected portion obtained by the production method of the present invention. In the present specification, it is simply referred to as a polarizer. It will be readily understood by those skilled in the art that the term " polarizer " means an intermediate or a polarizer having a retardation portion obtained by the production method of the present invention.

A. Manufacturing process of polarizing film laminate

In the method for producing a polarizer of the present invention, a polarizing film and a surface protective film disposed on one surface side of the polarizer are used, and a polarizing film laminate having an exposed portion where a polarizer is exposed on one surface side thereof is used as a basic solution Immersion is carried out. Since this polarizing film laminate has an exposed portion to which the polarizer is exposed, in the immersion treatment, only the portion where the polarizer is exposed comes into contact with the basic solution.

1 is a schematic cross-sectional view of a polarizing film laminate used in an embodiment of the present invention. The polarizing film laminate 100 is a long film and has a surface protective film (hereinafter also referred to as a first surface protective film) 50 having through holes 61, a polarizer 10, a protective film 20, 2 surface protective film 30 in this order. The surface protective films 50 and 30 are laminated via a pressure-sensitive adhesive layer (not shown) made of any suitable pressure-sensitive adhesive. In this embodiment, a polarizer including a polarizer 10 and a protective film 20 for protecting the polarizer 10 is used. However, when a polarizer having a shape other than the shape of a polarizer (for example, a polarizer , Resin substrate / polarizer laminated body) can be used. The polarizing film laminate 100 has an exposed portion 51 where the polarizer 10 is exposed from the through hole 61 on the side where the surface protective film 50 is disposed. In the present specification, the term " elongated phase " means an elongated shape having a sufficiently long length with respect to its width, and includes, for example, an elongated shape having a length of at least 10 times, preferably at least 20 times, do.

2 is a schematic perspective view of a polarizing film laminate according to an embodiment of the present invention. The exposed portions 51 may be arranged in a predetermined pattern. The exposed portions 51 are preferably arranged in a pattern having repeating units. In the present specification, " arranged in a pattern having repeating units " means that the polarizing film laminate is arranged in the same pattern every predetermined length in the longitudinal direction of the polarizing film laminate. The exposed portion 51 may be disposed at least along the longitudinal direction. The exposed portions 51 may be arranged at substantially equal intervals in the longitudinal direction and / or the width direction. In the illustrated example, the exposed portions 51 are arranged at substantially equal intervals in both the longitudinal direction and the width direction. In addition, " substantially equidistant in both the longitudinal direction and the width direction " means that the intervals in the longitudinal direction are equally spaced and the intervals in the width direction are equal intervals, and the interval in the longitudinal direction and the interval in the width direction Are not necessarily equal. For example, when the interval in the longitudinal direction is L1 and the interval in the width direction is L2, L1 = L2 or L1? L2. Since the exposed portions 51 are arranged in a pattern having a repetitive unit, the liquid can be brought into contact with a plurality of exposed portions in the same pattern for each of the repetitive units, so that the inclusion of bubbles can be suppressed more efficiently. As a result, the production efficiency of the polarizer having the non-light-emitting portion is further improved.

The polarizing film laminate 100 can be produced by laminating a long protective film 50 on the surface of the long polarizer 10. Fig. 3 is a schematic perspective view explaining the fusion of a surface protective film and a polarizing plate in a method of producing a polarizer using a surface protective film according to an embodiment of the present invention. Fig. In one embodiment, a polarizing film laminate is produced using a surface protective film having a long-axis polarizer and a long-axis pressure-sensitive adhesive layer. By using a surface protective film having a pressure-sensitive adhesive layer, a polarizing film laminate can be produced by roll-to-roll as shown in Fig. When the polarizing film laminate 100 is provided with the second surface protective film 30, the elongated second surface protective film 30 can be laminated with a roll film. The second surface protective film may be coextensive with the surface protective film having the penetrating holes at the same time, or it may be laminated before the surface protective film having the penetrating holes are bonded, or the surface protective film having the penetrating holes may be laminated and then laminated . Needless to say, the same procedure can be applied to a polarizer having a shape other than the shape of the polarizer (for example, a laminate of a polarizer, a resin substrate, and a polarizer as a single resin film).

A-1. Manufacture of Polarizers

As the polarizer 10 used in the polarizing film laminate 100, any suitable polarizer may be employed. The polarizer is typically composed of a resin film. The resin film is typically a polyvinyl alcohol resin (hereinafter referred to as " PVA resin ") film containing a dichroic substance such as iodine or organic dye. The resin film constituting the polarizer (typically, PVA resin film) may be a single film or may be a resin layer (typically, a PVA resin layer) formed on a resin substrate.

As the polarizer, a polarizer containing iodine is preferable. When the polarizer contains iodine as a dichroic substance, the iodine concentration in the exposed portion can be reduced by immersion in a basic solution described later, and as a result, the non-light-emitting portion can be selectively formed only in the exposed portion. This is because it is possible to selectively form the non-light-emitting portion in a predetermined portion of the polarizer at a very high manufacturing efficiency without complicated operations.

The polarizer can be produced by any suitable method. When the polarizer is a single PVA based resin film, the polarizer can be manufactured by a method well known in the art. When the polarizer is a PVA-based resin layer formed on a resin substrate, the polarizer may be manufactured by, for example, the method described in JP-A-2012-73580. This publication is incorporated herein by reference in its entirety.

The thickness of the polarizer can be set to any suitable value. The thickness is preferably 30 占 퐉 or less, more preferably 25 占 퐉 or less, further preferably 20 占 퐉 or less, particularly preferably 10 占 퐉 or less. On the other hand, the thickness is preferably 0.5 占 퐉 or more, and more preferably 1 占 퐉 or more. With such a thickness, a polarizer having excellent durability and optical characteristics can be obtained. Further, in the immersion step with a basic solution, the non-polarized portion can be formed satisfactorily as the thickness becomes thinner. For example, the contact time between the basic solution and the resin film (polarizer) can be shortened.

When a polarizing film laminate is manufactured using a polarizing plate, in one embodiment, a protective film is applied to one or both sides of a single polarizing film as a resin film. In another embodiment, a protective film is stuck to the surface of the polarizer of the laminate of the resin substrate / polarizer, then the resin substrate is peeled off, and another protective film may be stuck to the stuck surface of the resin substrate if necessary. In the present specification, a protective film is simply referred to as a polarizer protective film as described above, and is different from a surface protective film (a film that temporarily protects a polarizing plate during operation). The adhesion of the protective film can be typically performed by roll-to-roll.

Examples of the material for forming the protective film include cellulose resins such as diacetylcellulose and triacetylcellulose, olefinic resins such as (meth) acrylic resins, cycloolefin resins and polypropylene, polyethylene terephthalate resins and the like Ester-based resins, polyamide-based resins, polycarbonate-based resins, and copolymer resins thereof.

The thickness of the protective film is preferably 10 mu m to 100 mu m. Typically, the protective film is laminated on the polarizer via an adhesive layer (specifically, an adhesive layer and a pressure-sensitive adhesive layer). The adhesive layer is typically formed of a PVA-based adhesive or an activation energy ray-curable adhesive. The pressure-sensitive adhesive layer is typically formed of an acrylic pressure-sensitive adhesive.

The polarizing plate may further have any suitable optical function layer depending on the purpose. Typical examples of the optical function layer include a retardation film (optical compensation film) and a surface treatment layer.

A-2. Preparation of surface protective film

In the surface protective film 50, a through hole 61 corresponding to the position where the non-polarized portion of the polarizer (polarizer intermediate body) is formed is formed. In one embodiment, the surface protective film is a laminate having an arbitrary suitable resin film and a pressure-sensitive adhesive layer formed on one surface of the resin film, and has a through-hole penetrating the resin film and the pressure-sensitive adhesive layer.

The through holes 61 of the surface protective film 50 can be arranged substantially equally spaced in both the longitudinal direction and the width direction (Fig. 3). Alternatively, the through holes 61 may be arranged substantially equidistantly in the longitudinal direction, and may be arranged at different intervals in the width direction, or at different intervals in the longitudinal direction, (All not shown). When the through holes are arranged at different intervals in the longitudinal direction or the width direction, the intervals of the adjacent through holes may be different from each other, or only a part (interval between specific adjacent through holes) may be different. It is also possible to define a plurality of areas in the longitudinal direction of the surface protective film 50 and to set the intervals of the through holes 61 in the longitudinal direction and / or the width direction for each area. When only one polarizer of one size is cut from one long polarizer, the non-light portion can be arranged at substantially equal intervals in both the longitudinal direction and the width direction. With this configuration, it is easy to control cutting of the polarizer to a predetermined size in accordance with the size of the image display apparatus, and the yield can be improved. In addition, since the position of the non-light-emitting portion can be accurately set, the position of the non-light portion in the obtained polarizer of a predetermined size can be controlled well. As a result, the deviation of the position of the non-light-emitting portion for each polarizer of a predetermined size to be obtained becomes small, and thus a polarizer of a predetermined size without variation in quality can be obtained.

In one embodiment, the straight line connecting the adjacent through-holes in the longitudinal direction is substantially parallel to the longitudinal direction, and the straight line connecting the adjacent through-holes in the width direction is a width Direction of the substrate. In another embodiment, the straight line connecting the through holes adjacent to each other in the longitudinal direction is substantially parallel to the longitudinal direction, and the straight line connecting the adjacent through holes in the width direction is the width Lt; RTI ID = 0.0 ># _W < / RTI > In another embodiment, the through-hole 61 is formed so that the straight line connecting adjacent through holes in the longitudinal direction has a predetermined angle &thetas; _L with respect to the longitudinal direction, and connects the adjacent through- The straight line is arranged to have a predetermined angle? _W with respect to the width direction. [theta] _L and / or [theta] _w are preferably more than 0 [deg.] and less than +/- 10 [deg.]. Here, " ± " means to include either clockwise or counterclockwise rotation with respect to the reference direction (longitudinal direction or width direction). By immersing the polarizing film laminate having the surface protective film on which the through holes are arranged in the basic solution, the non-polarizing portion can be formed in a desired pattern while roll-transporting the polarizing film laminate of the elongated phase. As a result, the non-light-emitting portion can be formed by precisely controlling the arrangement pattern over the entirety of the long-axis polarizer. When the polarizer of a plurality of sizes is cut from one long polarizer by forming the non-light-emitting portion in a desired arrangement pattern, the size of the polarizer to be cut in the long and / . Here, in some image display devices, it is sometimes required to arrange the absorption axes of the polarizers at a maximum of about 10 degrees with respect to the long side or the short side of the device in order to improve display characteristics. Since the absorption axis of the polarizer is expressed in the longitudinal direction or the width direction, by forming the non-light-emitting portion using the above surface protective film, the positional relationship between the non-light-emitting portion and the absorption axis can be uniformly controlled , And a final product having excellent axial precision (and thus excellent optical characteristics) can be obtained. Therefore, it is possible to precisely control the direction of the absorption axis of the sheet polarizer in a cutting (for example, cutting and punching in the longitudinal direction and / or width direction) to a desired angle, The deviation of the direction of the axis can be remarkably suppressed. Needless to say, the arrangement pattern of the through holes is not limited to the illustrated example. For example, the straight line connecting the adjacent through holes in the longitudinal direction has a predetermined angle &thetas; _L with respect to the longitudinal direction, and the straight line connecting the adjacent through holes in the width direction, And may be arranged to be substantially parallel to the width direction. It is also possible to define a plurality of regions in the longitudinal direction of the surface protective film 50 _and set? _L and / or? _W for each region.

The shape of the first surface protective film as viewed from the plane of the through hole may be any suitable shape depending on the purpose. Specific examples include circular, elliptical, square, rectangular, and rhombic.

The through-holes of the first surface protective film can be removed by, for example, mechanical punching (e.g., punching, flake punching, plotter, water jet) or removal of certain portions of the first surface protective film Or chemical dissolution).

The first surface protective film is preferably a film having high hardness (e.g., elastic modulus). And deformation of the through hole at the time of conveyance and / or coaptation can be prevented. Examples of the material for forming the surface protective film include ester based resins such as polyethylene terephthalate based resins, cycloolefin based resins such as norbornene based resins, olefin based resins such as polypropylene, polyamide based resins, polycarbonate based resins And copolymer resins. Preferably, it is an ester-based resin (particularly, a polyethylene terephthalate-based resin). Such a material is advantageous in that the modulus of elasticity is sufficiently high and deformation of the through hole is difficult to occur even when tensile force is applied during conveyance and / or coalescence.

The thickness of the first surface protective film is preferably 20 μm to 250 μm, more preferably 30 μm to 150 μm. When the thickness of the surface protective film is within the above range, the inclusion of bubbles in transporting the polarizing film laminate to the treatment liquid is suppressed, and deformation of the through holes is suppressed even when tensile force is applied during transportation and / or lamination .

The elastic modulus of the first surface protective film is preferably 2.2 kN / mm 2 to 4.8 kN / mm 2. When the modulus of elasticity is within the above range, the inclusion of bubbles in transporting the polarizing film laminate to the treatment liquid is suppressed, and deformation of the through holes can be suppressed even when tensile force is applied during transportation and / or lamination. The elastic modulus is measured in accordance with JIS K 6781.

The tensile elongation of the first surface protective film is preferably 90% to 170%. When the tensile elongation of the surface protective film is within the above range, the inclusion of bubbles in transporting the polarizing film laminate to the treatment liquid is suppressed, and breakage of the film during transport can be prevented. The tensile elongation is measured in accordance with JIS K 6781.

The polarizing film laminate 100 may be provided with the second surface protective film 30 on the side where the surface protective film is not disposed as described above. As the second surface protective film, the same film as the surface protective film may be used, except that no through hole is formed. Also, as the second surface protective film, a soft film (for example, a low elastic modulus) such as a polyolefin (e.g., polyethylene) film may be used. By using the second surface protective film, the polarizing plate can be more appropriately protected. More specifically, it is possible to more appropriately protect the polarizing plate (polarizer / protective film) when immersed in the basic solution, and consequently, the formation of the non-light-emitting portion can be performed more favorably.

As the pressure-sensitive adhesive layer, any suitable pressure-sensitive adhesive layer can be employed as long as the effect of the present invention can be obtained. Examples of the base resin of the pressure-sensitive adhesive include acrylic resin, styrene resin, and silicone resin. Acrylic resin is preferable from the viewpoints of chemical resistance, adhesion for preventing intrusion of the treatment liquid at the time of immersion, degree of freedom to the adherend, and the like. The pressure-sensitive adhesive may contain a crosslinking agent. Examples of the crosslinking agent that can be contained in the pressure-sensitive adhesive include an isocyanate compound, an epoxy compound and an aziridine compound. The pressure-sensitive adhesive may contain, for example, a silane coupling agent. The compounding formulation of the pressure-sensitive adhesive may be suitably set according to the purpose.

The pressure-sensitive adhesive layer can be formed by any suitable method. Specific examples include a method in which a pressure sensitive adhesive solution is coated on a resin film and dried, a method in which a pressure sensitive adhesive layer is formed on a separator, and the pressure sensitive adhesive layer is transferred onto a resin film. Examples of the coating method include a roll coating method such as reverse coating and gravure coating, a spin coating method, a screen coating method, a fountain coating method, a dipping method and a spraying method.

The thickness of the pressure-sensitive adhesive layer is preferably 5 占 퐉 to 60 占 퐉, more preferably 5 占 퐉 to 30 占 퐉. If the thickness is too thin, the tackiness becomes insufficient, and air bubbles may enter the adhesive interface. If the thickness is excessively large, a problem that the pressure-sensitive adhesive leaks out tends to occur. The thickness of the pressure-sensitive adhesive layer can be adjusted together with the thickness of the resin film so that the thickness of the surface protective film is within the above range.

B. Liquid contact process

Fig. 4 is a schematic view showing a liquid contact process with the exposed portion of the polarizing film laminate according to one embodiment of the present invention and a process of immersing the polarizing film laminate into a basic solution; Fig. Figs. 5 and 6 are enlarged schematic views showing a liquid contact process to the exposed portion of the polarizing film laminate of Fig. 4. Fig.

In the liquid contacting step of the present invention, the liquid 90 is brought into contact with the side where the surface protective film 50 of the polarizing film laminate 100 is disposed. As an aspect of the contact, any appropriate aspect can be employed. Specifically, the liquid 90 may be sprayed onto the polarizing film laminate 100. In this embodiment, as shown in Figs. 4 and 5, the polarizing film laminate 100 is transported as a basic solution so that the exposed portion 51 is directed downward. That is, the side on which the surface protective film 50 of the polarizing film laminate 100 is disposed is the lower side of the polarizing film laminate 100. Therefore, in the illustrated example, the liquid 90 is ejected from the lower side of the polarizing film laminate 100. [

Any suitable liquid may be used as the liquid 90. The liquid 90 may be, for example, a basic solution the same as the basic solution in which the polarizing film laminate 100 is immersed. In the illustrated example, as the liquid 90, a basic solution in a basic solution tank in which the polarizing film laminate 100 is immersed is supplied by the pump 70. By using the same basic solution as the basic solution as the liquid 90, the concentration of the liquid in contact with the exposed portion does not change before and after immersion in the basic solution. As a result, in the step of immersing the polarizing film laminate in the basic solution after the liquid contacting step, the efficiency of discoloration of the exposed portion is improved. Therefore, the production efficiency of the polarizer having the non-light-emitting portion is further improved.

Any suitable means may be used as the means for bringing the liquid 90 into contact. In the illustrated example, the liquid 90 is brought into contact with the polarizing film laminate 100 by using the nozzle 80 for jetting the liquid 90. By using a nozzle as a means for contacting the liquid, it is easy to inject liquid directly to the exposed portion, so that the inclusion of bubbles can be suppressed more efficiently. As a result, the production efficiency of the polarizer having the non-light-emitting portion is further improved.

Preferably, the exposed portion 51 is arranged in a pattern having a repeating unit, and the liquid 90 is injected linearly onto the exposed portion 51 for each of the repeating units. Preferably, the liquid 90 is sprayed onto the exposed portion 51 using the nozzle 80 arranged corresponding to the arrangement of the exposed portions 51 in the repeating unit. In the example shown in Fig. 6, the exposed portions 51 are arranged at substantially equal intervals in both the longitudinal direction and the width direction, and the five exposed portions 51 are arranged in the width direction. Therefore, five exposed portions 51 are arranged in the same pattern for each interval in the longitudinal direction of the polarizing film laminate. The liquid (90) is divided into five flows by five valves (71). Five nozzles 80 corresponding to the five flows are arranged at the same interval as the above-mentioned interval in the width direction of the polarizing film laminate in which the exposed portions 51 are disposed. The five nozzles 80 eject the liquid 90 linearly onto the corresponding five exposed portions 51, respectively. The liquid 90 can be injected into the entire exposed portion of the repeating unit at one time by ejecting the liquid 90 linearly onto the exposed portion 51 for each repeating unit of the arrangement pattern of the exposed portion 51. [ Therefore, the inclusion of bubbles can be suppressed more efficiently, and as a result, the production efficiency of the polarizer having the non-light-emitting portion is further improved.

The liquid 90 may be in contact with the polarizing film laminate 100 in any suitable manner. More specifically, the liquid 90 may be injected in a straight line on the exposed portion 51, or the liquid 90 may be injected into the polarizing film laminate 100 from a pointed outlet, for example, in a conical shape, The liquid 90 may be injected into the film laminate 100 in a plane from the linear outlet. In the illustrated example, the liquid 90 is injected in a straight line on the exposed portion 51. Since the liquid can be efficiently brought into contact with the exposed portion by jetting the liquid linearly onto the exposed portion, the inclusion of bubbles can be suppressed more efficiently. As a result, the production efficiency of the polarizer having the non-light-emitting portion is further improved.

The liquid 90 may be intermittently contacted with the polarizing film laminate 100, or may be continuously contacted. By intermittently contacting the liquid, the liquid can be brought into contact with the arrangement of the exposed portions, and the liquid contacting the portions other than the exposed portions can be reduced, so that the inclusion of bubbles can be suppressed more efficiently. As a result, the production efficiency of the polarizer having the non-light-emitting portion is further improved.

Fig. 7 is a schematic partial enlarged view showing a liquid contact process carried out by another embodiment of the present invention. Fig. In the present embodiment, the polarizing film laminate 100 is transported as a basic solution so that the exposed portion 51 is directed upward. Therefore, in the illustrated example, the liquid 90 is ejected from the upper side of the polarizing film laminated body 100.

C. Immersion in basic solution

The method for producing a polarizer having a non-light-emitting portion of the present invention includes a step of immersing a polarizing film laminate having an exposed portion in a basic solution. In the case of using a polarizing film laminate of a long-axis phase, the polarizing film laminate is immersed while conveying, so that the decoloring treatment can be carried out, resulting in remarkably high production efficiency. As described above, in the polarizing film laminate used in the present invention, a first surface protective film (and a second surface protective film, if necessary) is used. Therefore, since the iodine concentration is not reduced at portions other than the exposed portion of the polarizing film laminate, the non-light-emitting portion can be formed by immersion. Specifically, by immersing the polarizing film laminate in the basic solution, only the exposed portion of the polarizing film laminate comes into contact with the basic solution.

The formation of the non-light-emitting portion by the basic solution will be described in more detail. After contact with the exposed portion of the polarizer in the polarizing film laminate, the basic solution penetrates into the exposed portion. The iodine complex contained in the exposed portion is reduced by the base contained in the basic solution to become an iodide ion. The iodine complex is reduced to iodine ions, whereby the polarization performance of the exposed portion is substantially lost and a non-polarized portion is formed in the exposed portion. Also, the reduction of the iodine complex improves the transmittance of the exposed portion. Iodine which has become iodine ion moves from the exposed portion into the solvent of the basic solution. As a result, by removing the basic solution described later, the iodide ion is removed from the exposed portion together with the basic solution. In this way, a non-polarizing portion is selectively formed in a predetermined portion of the polarizer, and the non-polarizing portion is stable without any change over time. Further, by adjusting the material, thickness and mechanical properties of the first surface protective film, the concentration of the basic solution, and the immersion time of the polarizing film laminate into the basic solution, etc., the basic solution penetrates to an undesired portion , And a non-polarized portion is formed in an undesired portion) can be prevented. Further, in the case where iodine remains in the polarizer, even when the iodine complex is destroyed to form the non-polarized portion, the iodine complex is formed again with use of the polarizer, and the non-polarized portion may not have the desired properties. In this embodiment, iodine itself is removed from the polarizer (substantially the non-light-blocking portion) by the removal of the basic solution described later. As a result, it is possible to prevent the characteristic change of the non-light-emitting portion accompanying the use of the polarizer.

In the immersion process, the polarizing film laminate can be immersed in the basic solution while flowing the basic solution. As a method of flowing the basic solution, any suitable method can be employed. In this method, for example, the basic solution may be stirred or the basic solution may be circulated. Any suitable direction can be employed in the direction of flow of the basic solution. In this direction, for example, it may be a direction from the first surface protective film side of the polarizer of the polarizing film laminate toward the opposite side. Since the basic solution flows, the bubbles contained in the exposed portion are easily excluded, so that the efficiency of producing the polarizer having the non-light-emitting portion is further improved.

As the basic compound contained in the basic solution, any suitable basic compound can be used. Examples of the basic compound include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide and lithium hydroxide, hydroxides of alkaline earth metals such as calcium hydroxide, inorganic alkali metal salts such as sodium carbonate, organic alkali metal salts such as sodium acetate and ammonia water. The basic compound contained in the basic solution is preferably a hydroxide of an alkali metal, more preferably sodium hydroxide, potassium hydroxide or lithium hydroxide. By using a basic solution containing a hydroxide of an alkali metal, the iodine complex can be efficiently ionized and the non-light-emitting portion can be formed more easily. These basic compounds may be used alone or in combination of two or more.

As the solvent for the basic solution, any suitable solvent may be used. Specific examples include water, alcohols such as ethanol and methanol, ether, benzene, chloroform, and mixed solvents thereof. The solvent is preferably water or an alcohol in that the iodide ion preferably migrates to the solvent and the iodide ion can be easily removed in the subsequent removal of the basic solution.

The concentration of the basic solution is, for example, 0.01 N to 5 N, preferably 0.05 N to 3 N, and more preferably 0.1 N to 2.5 N. When the concentration of the basic solution is within this range, the iodine concentration inside the polarizer can be effectively reduced, and the ionization of the iodine complex in the portion other than the exposed portion can be prevented.

The liquid temperature of the basic solution is, for example, 20 ° C to 50 ° C. The contact time of the polarizing film laminate (substantially the exposed portion of the polarizer) and the basic solution can be set according to the thickness of the polarizer, the kind of the basic compound contained in the basic solution to be used and the concentration of the basic compound, For 5 seconds to 30 minutes.

The basic solution may be removed by any suitable means as needed after contact with the exposed portion of the polarizer (after formation of the retarded portion). Specific examples of the basic solution removing method include aspiration removal, natural drying, heat drying, air blow drying, vacuum drying, and washing as described later. The drying temperature when the basic solution is removed by drying is, for example, 20 to 100 캜.

The immersion step with a basic solution may be carried out in a basic solution so that the exposed portion of the long polarizing film laminate is directed downward, or may be conveyed to a basic solution so that the exposed portion is directed upward.

D. Immersion treatment with other treatment liquid

The method for producing a polarizer having a non-light-emitting portion of the present invention may further include a step of immersing into a treatment solution other than the basic solution. As shown in Fig. 4, examples of the other treatment liquids include an acidic solution used for acid treatment of the polarizing film laminate, a cleaning liquid such as water used for cleaning, and the like.

D-1. Immersion process using an acidic solution (acid treatment)

The immersion step using the acidic solution is preferably performed in combination with the immersion step with the basic solution, and the immersion step using the acidic solution is preferably performed after the immersion step of the basic solution. By immersing the substrate in an acidic solution after immersing it in a basic solution, the basic solution remaining in the non-light-blocking portion can be removed to a better level. In addition, by bringing into contact with the acidic solution, the dimensional stability and durability of the non-light-emitting portion can be improved. The immersion step using the acidic solution may be carried out after the removal of the basic solution, or without removing the basic solution.

As the acidic compound contained in the acidic solution, any suitable acidic compound can be used. 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. The acidic compound contained in the acidic solution is preferably an inorganic acid, more preferably hydrochloric acid, sulfuric acid or nitric acid. These acidic compounds may be used alone or in combination.

As the solvent of the acidic solution, those exemplified as the solvent of the basic solution may be used. The concentration of the acidic solution is, for example, 0.01 N to 5 N, preferably 0.05 N to 3 N, and more preferably 0.1 N to 2.5 N.

The liquid temperature of the acidic solution is, for example, 20 ° C to 50 ° C. The contact time of the polarizing film laminate (substantially the exposed portion of the polarizer) and the acidic solution is set in accordance with the thickness of the resin film (polarizer), the kind of the acidic compound contained in the acidic solution to be used and the concentration of the acidic compound For example, 5 seconds to 30 minutes. If necessary, the polarizing film laminate and the acidic solution may be contacted with each other and then immediately removed.

The acidic solution may be removed after contact with the exposed portion of the polarizer, if necessary, by any suitable means. Specific examples of the method for removing the acidic solution include a process for removing a treatment liquid using a member for removing a treatment liquid, a cleaning, and the like, which are carried out by aspiration, natural drying, heat drying, air drying, and vacuum drying. When the acidic solution is removed by drying, it can be carried out, for example, by transporting the polarizing film laminate in an oven. The drying temperature is, for example, 20 ° C to 100 ° C, and the drying time is, for example, 5 seconds to 600 seconds.

D-2. washing

The cleaning may be carried out in order to remove the processing liquid or foreign matter adhering to the surface of the polarizing film laminate in each step. For example, the production method of the present invention can be carried out after the immersion step with the basic solution and / or the immersion step with the acidic solution.

Examples of the liquid (cleaning liquid) used for cleaning include water (pure water), alcohol such as methanol and ethanol, acidic aqueous solution, mixed solvent thereof, and the like. Preferably, it is water. The cleaning may be performed once or plural times of cleaning may be performed as one step.

The treatment liquid after the cleaning can be removed by any suitable means if necessary. Specific examples of the method for removing the treatment liquid after cleaning include a step of removing by suction, natural drying, heat drying, blow drying, drying under reduced pressure, and a removal step by any appropriate member.

E. Other processes

The production process of the present invention may include any suitable process other than those exemplified in the above A to D. For example, a process for removing the process liquid used in the immersion process, a drying process, and the like can be given.

The method for producing a polarizer having a non-light-emitting portion of the present invention may include a step of removing the treatment liquid used in the immersion step. Examples of the process liquid removing process include a drying process to be described later, a process liquid removing process for bringing an arbitrary absorbing material such as cloth, waist, sponge or the like into contact with the surface protective film side of the polarizing film laminate, , Wiping, etc.).

By including the removal step by any suitable member, the treatment liquid can be removed more sufficiently. Thus, it is possible to prevent an adverse effect on the untreated portion due to the treatment liquid and a defective appearance of the resulting polarizer.

The drying means can be carried out by any suitable method. Examples of the drying means include an oven, an air blow, and an air knife. The drying temperature and the drying time may be set to any appropriate values depending on the thickness and characteristics of the polarizing film laminate.

After the necessary process is completed, the first surface protective film (and second surface protective film, if present) can be peeled off from the polarizing film laminate.

F. Polarizer having a non-light-emitting portion

The manufacturing method of the present invention is capable of preventing the inclusion of bubbles in the exposed portion of the polarizing film laminate as described above. Therefore, in the polarizer obtained by the production method of the present invention, problems such as defective discoloration of the non-light-emitting portion can be suppressed. Therefore, the polarizer provided by the production method of the present invention can have excellent quality. The polarizer having the non-light-emitting portion of the present invention is preferably used for an image display device (liquid crystal display device, organic EL device) equipped with a camera such as a mobile phone such as a smart phone, a notebook PC, and a tablet PC. When applied to these, the non-light-emitting portion can correspond to the camera hole portion of these devices. When the non-polarized portion corresponds to the camera hole portion, not only the transparency of the camera hole portion is ensured but also the brightness and color taste at the time of photographing are optimized and the image is prevented from being deformed to contribute to improvement of the camera performance of the obtained image display device. have. The polarizer having the non-light-emitting portion of the present invention can be used not only for a portable electronic device such as an image or a monitor (for example, a camera device having a photographing optical system), but also for a transmission type electronic device such as an LED light or an infrared sensor, And can be suitably used for an image display device which secures transparency and straightness of light.

The transmittance Ts of the obtained polarizer (excluding the non-light-emitting portion) is preferably 39% or more, more preferably 39.5% or more, still more preferably 40% or more, particularly preferably 40.5% or more. Further, the theoretical upper limit of the mass transmittance is 50%, and the practical upper limit is 46%. Note that the unitary transmittance Ts is a Y value obtained by performing visibility correction by measuring with a 2-degree field of view (C light source) of JIS Z 8701 and using a microscopic spectroscopic system (LV micro, manufactured by Lambda Vision) Can be measured. The degree of polarization (excluding the non-light-emitting portion) of the polarizer is preferably not less than 99.9%, more preferably not less than 99.93%, further preferably not less than 99.95%.

The transmittance of the non-light-emitting portion (for example, the transmittance measured with light having a wavelength of 550 nm at 23 캜) is preferably 50% or more, more preferably 60% or more, further preferably 75% , And particularly preferably 90% or more. With such a transmittance, desired transparency as a non-light-emitting portion can be secured. As a result, when the polarizer is arranged so that the non-polarized portion corresponds to the camera portion of the image display apparatus, adverse effects on the photographing performance of the camera can be prevented.

Any appropriate shape can be employed as long as the shape of the non-light-emitting portion viewed from the plane does not adversely affect the camera performance of the image display device in which the polarizer is used. The shape in the plane of the non-light-emitting portion corresponds to the shape of the through hole of the first surface protective film.

In one embodiment, the absorption axis of the polarizer is substantially parallel to the longitudinal direction or the width direction, and both ends of the polarizer are slit-processed parallel to the longitudinal direction. With such a configuration, by performing the cutting operation with reference to the end face of the polarizer, it is possible to easily manufacture a plurality of polarizers having the non-light-emitting portion and the absorption axis in the proper direction.

The polarizer can be practically provided as a polarizing plate. The polarizing plate has a protective film disposed on at least one side of the polarizer and the polarizer (not shown). Practically, the polarizing plate has a pressure-sensitive adhesive layer as an outermost layer. The pressure-sensitive adhesive layer is typically the outermost layer on the side of the image display apparatus. The separator is temporarily mounted on the pressure-sensitive adhesive layer so that the separator can be peeled off, thereby protecting the pressure-sensitive adhesive layer until actual use, and enabling roll formation.

The polarizing plate may further have any suitable optical functional layer depending on the purpose. Typical examples of the optical function layer include a retardation film (optical compensation film) and a surface treatment layer. For example, a retardation film may be disposed between the protective film and the pressure-sensitive adhesive layer. The optical characteristics (for example, the refractive index ellipsoid, in-plane retardation, thickness direction retardation) of the retardation film can be appropriately set according to the purpose, the characteristics of the image display apparatus, and the like. For example, when the image display apparatus is an IPS mode liquid crystal display apparatus, a retardation film having a refractive index ellipsoid of nx> ny> nz and a retardation film having a refractive index ellipsoid of nz> nx> ny may be disposed. The retardation film may also serve as a protective film. In this case, the protective film may be omitted. On the contrary, the protective film may have an optical compensation function (that is, it may have an appropriate refractive index ellipsoid depending on the purpose, in-plane retardation and thickness retardation). "Nx" is the refractive index in the direction in which the refractive index in the film plane becomes the maximum (that is, the slow axis direction), "ny" is the refractive index in the direction perpendicular to the slow axis in the film plane, "nz" .

The surface treatment layer can be disposed on the viewer side of the polarizing plate. Typical examples of the surface treatment layer include a hard coat layer, an antireflection layer, and an antiglare layer. The surface treatment layer is preferably a layer having a low moisture permeability for the purpose of improving durability of humidification of the polarizer, for example. The hard coat layer is formed for the purpose of preventing flaws on the surface of the polarizing plate. The hard coat layer can be formed by, for example, a method of adding a cured coating film having excellent hardness, sliding characteristics, and the like to an ultraviolet curable resin such as acrylic or silicone. The hard coat layer preferably has a pencil hardness of 2 H or more. The antireflection layer is a low reflection layer formed for the purpose of preventing reflection of external light on the surface of the polarizing plate. Examples of the antireflection layer include a thin layer type which is disclosed in Japanese Patent Application Laid-Open No. 2005-248173, which prevents reflection by utilizing the effect of eliminating the reflected light due to the interference action of light, And a surface structure type which exhibits a low reflectance by imparting a fine structure to the surface. The anti-glare layer is formed for the purpose of preventing external light from being reflected on the surface of the polarizing plate to prevent visibility of the light transmitted through the polarizing plate. The anti-glare layer is formed, for example, by imparting fine concavo-convex structure to the surface by an appropriate method such as a sandblast method, a roughening method by an embossing method, or a blending method of transparent fine particles. The anti-glare layer may also serve as a diffusion layer (time magnification function or the like) for diffusing the polarized-plate transmitted light to enlarge the viewing angle or the like. Instead of forming the surface treatment layer, the surface of the protective film on the viewer side may be subjected to the same surface treatment.

Industrial availability

The polarizer of the present invention is preferably used for an image display device (liquid crystal display device, organic EL device) equipped with a camera such as a mobile phone such as a smart phone, a notebook PC, and a tablet PC.

10: Polarizer
20: Protective film
30: Second surface protective film
50: First surface protection film
51: Exposed portion
70: Pump
80: Nozzle
90: liquid
100: polarizing film laminate

Claims (5)

A step of bringing the liquid into contact with the one surface side of the elongated polarizing film laminate having the polarizer and the surface protective film disposed on the one surface side of the polarizer and having the exposed portion in which the polarizer is exposed on the one surface side;
And a step of immersing the polarizing film laminate in a basic solution after the liquid contacting step,
Wherein the liquid is a basic solution same as the basic solution. delete The method according to claim 1,
And the liquid is brought into contact with the one surface side of the polarizing film laminate by using a nozzle for jetting the liquid. The method of claim 3,
And the liquid is sprayed linearly onto the exposed portion. 5. The method of claim 4,
Wherein the exposed portion is arranged in a pattern having a repeating unit, and the liquid is sprayed linearly onto the exposed portion for each of the repeating units.

Images