WO2016052549A1

WO2016052549A1 - One-side-protected polarizing film, adhesive-layer-equipped polarizing film, image display device, and method for continuously producing same

Info

Publication number: WO2016052549A1
Application number: PCT/JP2015/077590
Authority: WO
Inventors: 聡司三田; 友徳上野; 菁▲王番▼ 徐; 佑輔茂手木; 岸　敦史
Original assignee: 日東電工株式会社
Priority date: 2014-09-30
Filing date: 2015-09-29
Publication date: 2016-04-07

Abstract

The present invention pertains to a one-side-protected polarizing film having a protective film on only one surface of a polarizer, wherein: the polarizer contains a polyvinyl alcohol resin, and is configured in a manner such that the optical properties thereof, represented by the single-body transmittance T and the degree of polarization P, satisfy the condition of P>-(10^0.929T-42.4-1)×100 (however, T<42.3) or P≥99.9 (however, T≥42.3); and X≤12, Y≤15, 0.15≤(Y/X)≤3 are satisfied, given that the thickness of the polarizer is X (μm) and the thickness of the transparent resin layer is Y (μm). Even when the thin-type polarizer has prescribed optical properties, this one-side-protected polarizing film is capable of suppressing the occurrence of curling and defects caused by through-cracks and nanoslits.

Description

Single protective polarizing film, polarizing film with pressure-sensitive adhesive layer, image display device, and continuous production method thereof

The present invention relates to a piece protective polarizing film in which a protective film is provided only on one side of a polarizer and a polarizing film with a pressure sensitive adhesive layer having the piece protective polarizing film and a pressure sensitive adhesive layer. The single-protective polarizing film and the polarizing film with the pressure-sensitive adhesive layer can form an image display device such as a liquid crystal display device (LCD) or an organic EL display device as a single or a laminated optical film.

In a liquid crystal display device, it is indispensable to dispose polarizing films on both sides of a glass substrate that forms the surface of a liquid crystal panel because of its image forming method. In general, a polarizing film in which a protective film is bonded to one or both sides of a polarizer made of a dichroic material such as a polyvinyl alcohol film and iodine with a polyvinyl alcohol adhesive or the like is used. .

When adhering the polarizing film to a liquid crystal cell or the like, an adhesive is usually used. In addition, since the polarizing film can be fixed instantaneously and has a merit such that a drying step is not required to fix the polarizing film, the adhesive is provided in advance as an adhesive layer on one side of the polarizing film. . That is, a polarizing film with an adhesive layer is generally used for attaching the polarizing film.

In addition, a polarizing film or a polarizing film with a pressure-sensitive adhesive layer can cause the polarizer to contract in a severe environment of thermal shock (for example, a heat shock test in which temperature conditions of −30 ° C. and 80 ° C. are repeated or a test at a high temperature of 100 ° C.) There is a problem that cracks (through cracks) are likely to occur in the entire absorption axis direction of the polarizer due to the change in stress. That is, the polarizing film with an adhesive layer was not sufficiently durable due to thermal shock in the harsh environment. In particular, from the viewpoint of thinning, a polarizing film with a pressure-sensitive adhesive layer using a piece protective polarizing film in which a protective film is provided only on one side of a polarizer has insufficient durability due to the thermal shock. Moreover, the penetration crack produced by the said thermal shock was easy to generate | occur | produce when the size of a polarizing film became large.

In order to suppress the occurrence of the through cracks, for example, a polarizing film with an adhesive layer in which a protective layer having a tensile modulus of 100 MPa or more is provided on a single protective polarizing film and an adhesive layer is further provided on the protective layer has been proposed. (Patent Document 1). Moreover, it has a protective layer made of a cured product of the curable resin composition on one side of a polarizer having a thickness of 25 μm or less, a protective film on the other side of the polarizer, and an adhesive on the outside of the protective layer A polarizing film with an adhesive layer having a layer has been proposed (Patent Document 2). The polarizing film with the pressure-sensitive adhesive layer described in

Patent Documents

1 and 2 is effective in terms of suppressing the occurrence of through cracks. Thinning is also performed for polarizers, and for example, a thin polarizer exhibiting high orientation in which optical characteristics of single transmittance and polarization degree are controlled has been proposed (Patent Document 3).

JP 2010-009027 A JP 2013-160775 A Japanese Patent No. 4751481

In

Patent Documents

1 and 2, the thickness is reduced by using a piece protective polarizing film having a protective film only on one side of a polarizer, and on the other hand, by providing a protective layer, the piece protective polarizing film is used. Generation of through cracks in the direction of the absorption axis of the polarizer is suppressed.

On the other hand, thinning is also done for polarizers. When the polarizer used for the polarizing film or the polarizing film with the pressure-sensitive adhesive layer is thinned, the change in the contraction stress of the polarizer becomes small. Therefore, it has been found that the thinned polarizer can suppress the occurrence of the through cracks.

However, in the half-protective polarizing film in which the generation of the through cracks is suppressed or the polarizing film with the pressure-sensitive adhesive layer using the same, the optical characteristics are controlled as in Patent Document 3 and the polarizer is thinned (for example, When the thickness is 10 μm or less), when a mechanical shock is applied to the one-side protective polarizing film or the polarizing film with an adhesive layer using the same (including the case where a load due to convex folding is applied to the polarizer side), It was found that a very fine slit (hereinafter also referred to as nano slit) is generated in the absorption axis direction of the polarizer. It was also found that the nano slits occur regardless of the size of the polarizing film. Furthermore, it was also found that the nano slit does not occur when both protective polarizing films having protective films on both sides of the polarizer are used. In addition, when a through crack occurs in the polarizer, the stress around the through crack is released, so the through crack does not occur adjacently. I found it to happen. Moreover, although the penetration crack has the progressive property extended in the absorption-axis direction of the polarizer in which the crack generate | occur | produced, it turned out that a nano slit does not have the said progressive property. As described above, the nano slit is a new problem that occurs when the polarizer is thin and the optical characteristics are controlled within a predetermined range in the single-protective polarizing film in which the generation of through cracks is suppressed. It has been found that this is a problem caused by a phenomenon different from the above-described through crack.

Moreover, since the nano slit is extremely thin, it cannot be detected under a normal environment. Therefore, even if nanoslits are generated in the polarizer, it is difficult to confirm the defects due to light leakage of the one-side protective polarizing film and the polarizing film with the pressure-sensitive adhesive layer using it. That is, usually, the piece-protecting polarizing film is produced in the form of a long film and automatically inspected for defects by optical inspection, but it is difficult to detect nanoslits as defects by this defect inspection. The defect caused by the nano slit is that the nano slit spreads in the width direction when the single protective polarizing film or the polarizing film with the adhesive layer is bonded to the glass substrate of the image display panel and placed in a heating environment. It was also found that detection is possible (for example, the presence or absence of light leakage).

Therefore, it is desired to suppress not only through cracks but also defects due to nano slits in the single-protective polarizing film using a thin polarizer or the polarizing film with an adhesive layer using the same. Furthermore, in the single-protective polarizing film or the polarizing film with an adhesive layer using the same, the polarizing film is likely to be broken or broken during handling because it is thin compared to the polarizing film having both protective structures having protective films on both sides. . Therefore, at the time of handling, it is desired that the polarizing film or the polarizing film with an adhesive layer using the same is not curled. In addition, in a single-protective polarizing film with a protective layer in which a protective layer is provided on the single-protective polarizing film by solidification or curing, the material forming the protective layer shrinks during the formation of the protective layer, so that there is a gap between the polarizer and the protective layer. Stress easily accumulates and curls are likely to occur. For this reason, it is desirable that no curling occurs in the single-protective polarizing film or the polarizing film with the pressure-sensitive adhesive layer using the same from the viewpoint of handleability.

The present invention provides a single protective polarizing film having a protective film only on one surface of a thin polarizer, the polarizer having predetermined optical characteristics, and suppressing the occurrence of defects and curls due to through cracks and nano slits. An object of the present invention is to provide a piece protective polarizing film that can be used. Moreover, this invention aims at providing the polarizing film with an adhesive layer which has the said piece protection polarizing film and an adhesive layer.

Another object of the present invention is to provide an image display device having the piece protective polarizing film or the pressure-sensitive adhesive layer-attached polarizing film, and a continuous production method thereof.

As a result of intensive studies, the present inventors have found that the above-described problems can be solved by the following piece-protecting polarizing film, polarizing film with an adhesive layer, and the like, and have reached the present invention.

That is, the present invention is a piece protective polarizing film having a protective film only on one side of the polarizer,
The polarizer contains a polyvinyl alcohol-based resin, and has an optical characteristic represented by a single transmittance T and a polarization degree P of the following formula: P> − (10 ^0.929T-42.4 −1) × 100 (Where T <42.3), or
P ≧ 99.9 (provided that T ≧ 42.3) is satisfied,
And when the thickness of the polarizer is X (μm) and the thickness of the transparent resin layer is Y (μm),
X ≦ 12,
Y ≦ 15,
It is related with the piece protection polarizing film characterized by satisfying 0.15 <= (Y / X) <= 3.

In the piece protective polarizing film, the transparent resin layer preferably has a compression elastic modulus at 80 ° C. of 0.1 GPa or more.

In the one-piece protective polarizing film, the transparent resin layer is preferably formed of an ultraviolet curable acrylic resin, an ultraviolet curable epoxy resin, a urethane resin, or a polyvinyl alcohol resin.

The piece protective polarizing film preferably has an adhesive layer between the polarizer and the protective film. The thickness of the adhesive layer is preferably 0.1 μm or more and 5 μm or less. The adhesive layer preferably has a compressive elastic modulus at 80 ° C. of 0.1 GPa or more and 10 GPa or less. The adhesive layer is preferably formed of an ultraviolet curable acrylic resin, an ultraviolet curable epoxy resin, a urethane resin, or a polyvinyl alcohol resin.

In the piece protective polarizing film, when the number of the protective films is one, the thickness of the protective film is preferably 10 μm or more and 100 μm or less.

In the single protective polarizing film, when there are two protective films, the thickness of each protective film is 10 μm or more, and the total thickness of the protective films is 100 μm or less. It preferably has an agent layer or an adhesive layer.

In the piece protective polarizing film, the polarizer preferably contains boric acid in an amount of 25% by weight or less based on the total amount of the polarizer.

The present invention also relates to the above-mentioned piece protective polarizing film and a polarizing film with an adhesive layer, characterized by having an adhesive layer.

In the polarizing film with an adhesive layer, the thickness of the adhesive layer is preferably 1 μm or more and 40 μm or less. The pressure-sensitive adhesive layer preferably has a storage elastic modulus at 23 ° C. of 1.0 × 10 ⁴ Pa or more.

The polarizing film with the pressure-sensitive adhesive layer can be used in a mode in which the pressure-sensitive adhesive layer is provided on the transparent resin layer of the piece protective polarizing film. Moreover, the said polarizing film with an adhesive layer can be used in the aspect by which the said adhesive layer is provided in the protective film of the said piece protection polarizing film. Moreover, a separator can be provided in the adhesive layer of the polarizing film with an adhesive layer. The polarizing film with an adhesive layer provided with a separator can be used as a wound body.

The present invention also relates to an image display device having the piece protective polarizing film or the polarizing film with an adhesive layer.

In the present invention, the polarizing film with the pressure-sensitive adhesive layer fed out from the wound body of the polarizing film with the pressure-sensitive adhesive layer and conveyed by the separator is continuously applied to the surface of the image display panel via the pressure-sensitive adhesive layer. The present invention relates to a continuous manufacturing method of an image display device including a step of bonding to a substrate.

The piece-protecting polarizing film and the polarizing film with a pressure-sensitive adhesive layer of the present invention use a polarizer having a thickness of 12 μm or less, and are thinned. In addition, since the thin polarizer having a thickness of 12 μm or less has a smaller change in shrinkage stress applied to the polarizer due to thermal shock than in the case where the thickness of the polarizer is large, the occurrence of through cracks can be suppressed.

On the other hand, a thin polarizer having predetermined optical characteristics is likely to generate nano slits in the polarizer. The nano-slit is a process for producing a piece-protecting polarizing film, a step for producing a polarizing film with a pressure-sensitive adhesive layer in which a pressure-sensitive adhesive layer is provided on the piece-protecting polarizing film, and various steps after producing a polarizing film with a pressure-sensitive adhesive layer. It is considered to occur when a mechanical shock is applied to the polarizing film or the polarizing film with the pressure-sensitive adhesive layer using the polarizing film, and is assumed to be generated by a mechanism different from the through crack generated by the thermal shock. In addition, the defect due to the nano slit is that when the single protective polarizing film or the polarizing film with the pressure-sensitive adhesive layer is bonded to the glass substrate of the image display panel and placed in a heating environment, the nano slit is in the width direction. Detection is possible by spreading (for example, the presence or absence of light leakage).

In the piece protective polarizing film and the polarizing film with the pressure-sensitive adhesive layer of the present invention, a piece before provision of the transparent resin layer is provided by providing a transparent resin layer on the other side of the polarizer (the side having no protective film). Even when the nano slits are generated in the polarizer in the state of the protective polarizing film, the generation of defects due to the spread of the nano slits in the width direction can be suppressed. In particular, a transparent resin layer having a compression elastic modulus at 80 ° C. of 0.1 GPa or more is effective.

As described above, the piece-protecting polarizing film of the present invention and the polarizing film with the pressure-sensitive adhesive layer using the same have a transparent resin layer, satisfying a reduction in thickness, and having through cracks and nano-particles generated in the polarizer. Defects due to slits can be suppressed.

Moreover, in the piece protection polarizing film and the polarizing film with an adhesive layer of this invention, the thickness X (micrometer) of a thin polarizer and the thickness Y (micrometer) of a transparent resin layer are X <= 12 and Y <= 15. , 0.15 ≦ (Y / X) ≦ 3, despite the provision of a transparent resin layer capable of suppressing defects due to through cracks and nano slits generated in the polarizer. Therefore, the occurrence of curling can be suppressed.

It is an example of the schematic sectional drawing of the piece protection polarizing film of this invention. It is an example of schematic sectional drawing of the polarizing film with an adhesive layer of this invention. It is an example of the conceptual diagram which contrasts the nano slit and penetrating crack which arise in a polarizer. It is an example of the photograph of the cross-sectional view of the piece protection polarizing film which shows that the expansion of the nano slit by heating differs depending on the presence or absence of the generation of the nano slit and the presence or absence of the transparent resin layer when the nano slit is generated. It is the schematic explaining the evaluation item which concerns on the nano slit of an Example and a comparative example. It is an example of the photograph which shows the crack produced by the nano slit which concerns on an evaluation of an Example and a comparative example. It is an example of the photograph which shows the progress of the penetration crack which concerns on an evaluation of an Example and a comparative example. It is an example of the schematic sectional drawing of the continuous manufacturing system of an image display apparatus.

Hereinafter, the piece protective polarizing film 11 and the polarizing film 12 with an adhesive layer of the present invention will be described with reference to FIGS. The single protective polarizing film 10 (in the case where the transparent resin layer 3 is not provided) has the protective film 2 only on one surface of the polarizer 1, for example, as shown in FIG. The polarizer 1 and the protective film 2 are laminated via an adhesive layer 2a (other intervening layers such as a pressure-sensitive adhesive layer and an undercoat layer (primer layer)). Moreover, although not shown in figure, the piece protection polarizing film 10 can laminate | stack the said easily bonding layer and an adhesive bond layer by providing an easily bonding layer in the protective film 2, or performing an activation process. As shown in FIG. 1, the single-protective polarizing film 11 (with the transparent resin layer 3) of the present invention has, on the single-sided protective polarizing film 10, the other surface of the polarizer 1 (the surface not having the protective film 2). A transparent resin layer 3 is provided (directly). In addition, as shown in FIG. 1B, a plurality of protective films 2 can be provided. FIG. 1B shows a single protective polarizing film (with a transparent resin layer) 11 ′ provided with two

protective films

2 and 2 ′. The protective film 2 and the protective film 2 ′ can be laminated by an adhesive layer 2a (other intervening layers such as a pressure-sensitive adhesive layer and an undercoat layer (primer layer)).

As described above, the thickness of the polarizer is X (μm), and the thickness Y (μm) of the transparent resin layer satisfies X ≦ 12, Y ≦ 15, and 0.15 ≦ (Y / X) ≦ 3. Designed to be. From the viewpoint of suppressing defects due to nano slits generated in the polarizer, the value (Y / X) is preferably 0.24 or more. On the other hand, from the viewpoint of curling suppression, the value (Y / X) is preferably 0.8 or less, and more preferably 0.5 or less. The value (Y / X) is preferably 0.24 ≦ (Y / X) ≦ 0.8, and more preferably 0.24 ≦ (Y / X) ≦ 0.5. .

Moreover, the polarizing film 12 with an adhesive layer of this invention has the piece protection polarizing film (with transparent resin layer) 11 and the adhesive layer 4, as shown in FIG. The pressure-sensitive adhesive layer 4 is provided on the transparent resin layer 3 side in FIG. 2A and on the protective film 2 side in FIG. In addition, the separator 5 can be provided in the adhesive layer 4 of the polarizing film 12 with an adhesive layer of this invention, and the surface protection film 6 can be provided in the other side. In the polarizing film 12 with an adhesive layer of FIG. 2, the case where both the separator 5 and the surface protection film 6 are provided is shown. The pressure-sensitive adhesive layer-attached polarizing film 12 having at least the separator 5 (and further having the surface protective film 6) can be used as a wound body, and as described later, for example, the separator 5 is fed out from the wound body. The polarizing film 12 with the pressure-sensitive adhesive layer conveyed by the above is also referred to as a “roll-to-panel method” (hereinafter referred to as “roll-to-panel method”). This is advantageous for application to the specification No. 4406043. As a polarizing film with an adhesive layer, the aspect shown to FIG. 2 (A) is preferable from viewpoints, such as suppression of the curvature of the display panel after bonding, generation | occurrence | production suppression of a nano slit. The surface protective film 6 can be provided on the piece protective polarizing film 10 and the piece protective polarizing film 11 (with a transparent resin layer). In addition, in FIG. 2, although the case where the piece protection polarizing film 11 (with a transparent resin layer) 11 of FIG. 1 (A) is used is illustrated, the piece protection polarizing film (with a transparent resin layer) of FIG. 11 'can also be used.

FIG. 3 is a conceptual diagram comparing the nano slit a and the through crack b generated in the polarizer. 3A shows a nano slit a generated in the polarizer 1, and FIG. 3B shows a through crack b generated in the polarizer 1. FIG. The nano slit a is generated by mechanical impact and is partially generated in the absorption axis direction of the polarizer 1. The nano slit a cannot be confirmed at the beginning, but is in a thermal environment (for example, 80 ° C. or 60 ° C., 90% RH), it can be confirmed by the spread in the width direction. On the other hand, it is considered that the nano slit a does not have a progressive property extending in the absorption axis direction of the polarizer. Moreover, it is thought that the said nano slit a arises irrespective of the size of a polarizing film. The nano slits a may occur not only independently but also adjacent to each other. On the other hand, the through crack b is generated by a thermal shock (for example, a heat shock test). The through crack has a process of extending in the absorption axis direction of the polarizer where the crack has occurred. When the through crack b is generated, the peripheral stress is released, so that the through crack does not occur adjacently.

FIG. 4 is an example of a photograph of a cross-sectional view of the piece protective polarizing film 10 or the piece protective polarizing film 11 with a transparent resin layer related to generation, expansion, and repair of nano slits a generated in the polarizer. FIG. 4 (A) is an example of a case where the single protective polarizing film 10 having the protective film 2 on only one surface of the polarizer 1 via the adhesive layer 2a and no nanoslit is generated. FIG. 4B is an example when nano slits a are generated in the piece protective polarizing film 10. 4A and 4B are both before heating. Moreover, FIG.4 (C) is an example of the photograph of sectional drawing after heating the piece protection polarizing film 10 in which the nano slit a has generate | occur | produced. In FIG.4 (C), it turns out that the nano slit a of the polarizer 1 is expanded by heating. On the other hand, FIG. 4 (D) is an example of a photograph of a cross-sectional view of the piece protective polarizing film 11 with a transparent resin layer in which the transparent resin layer 3 is formed on the piece protective polarizing film 10 in which the nano slits a are generated. In FIG. 4D, it can be seen that the nano slits a generated in the polarizer 1 are repaired (a ′) by the transparent resin layer 3. Moreover, FIG.4 (E) is an example of the photograph of sectional drawing after heating the piece protection polarizing film 11 with the transparent resin layer in which the transparent resin layer 3 was formed. In FIG. 4E, it can be seen that there is no expansion of the repaired (a ′) nanoslit after heating. In FIG. 4, the section was cut with a cross session polisher or a microtome perpendicular to the absorption axis direction of the sample, and observed with a scanning electron microscope.

<Polarizer>
In the present invention, a polarizer having a thickness of 12 μm or less is used. The thickness of the polarizer is preferably 10 μm or less, more preferably 8 μm or less, further preferably 7 μm or less, and further preferably 6 μm or less from the viewpoint of reducing the thickness and preventing the occurrence of through cracks. On the other hand, the thickness of the polarizer is preferably 2 μm or more, and more preferably 3 μm or more. Such a thin polarizer has less thickness unevenness, excellent visibility, and less dimensional change, and therefore excellent durability against thermal shock.

A polarizer using a polyvinyl alcohol resin is used. Examples of polarizers include dichroic iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. Examples thereof include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic material such as iodine is preferable.

A polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol in an aqueous iodine solution and stretching it 3 to 7 times the original length. If necessary, it may contain boric acid, zinc sulfate, zinc chloride, or the like, or may be immersed in an aqueous solution such as potassium iodide. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with dirt and anti-blocking agents by washing the polyvinyl alcohol film with water, it also has the effect of preventing unevenness such as uneven coloring by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched even in an aqueous solution such as boric acid or potassium iodide or in a water bath.

The polarizer preferably contains boric acid from the viewpoint of stretching stability and optical durability. Further, the content of boric acid contained in the polarizer is preferably 25% by weight or less, more preferably 20% by weight or less, based on the total amount of the polarizer, from the viewpoint of suppressing the generation of through cracks and nano slits and suppressing expansion. Preferably, it is 18% by weight or less, and more preferably 16% by weight or less. When the content of boric acid contained in the polarizer exceeds 20% by weight, it is preferable because even if the thickness of the polarizer is controlled to 10 μm or less, the contraction stress of the polarizer is increased and through cracks are likely to occur. Absent. On the other hand, from the viewpoint of the stretching stability and optical durability of the polarizer, the boric acid content with respect to the total amount of the polarizer is preferably 10% by weight or more, and more preferably 12% by weight or more.

As a thin polarizer, typically,
Patent No. 4751486,
Japanese Patent No. 4751481,
Patent No. 4815544,
Patent No. 5048120,
Japanese Patent No. 5587517,
International Publication No. 2014/077599 pamphlet,
International Publication No. 2014/077636 Pamphlet,
And the thin polarizers obtained from the production methods described therein.

The polarizer has an optical characteristic expressed by a single transmittance T and a polarization degree P of the following formula P> − (10 ^0.929T-42.4 −1) × 100 (where T <42.3), Or
It is configured to satisfy the condition of P ≧ 99.9 (however, T ≧ 42.3). A polarizer configured so as to satisfy the above-described conditions uniquely has performance required as a display for a liquid crystal television using a large display element. Specifically, the contrast ratio is 1000: 1 or more and the maximum luminance is 500 cd / m ² or more. As other uses, for example, it is bonded to the viewing side of the organic EL display device.

On the other hand, a polarizer configured to satisfy the above conditions has a high orientation of a polymer (for example, a polyvinyl alcohol-based molecule), so that the thickness of the polarizer is 10 μm or less. The tensile breaking stress in the direction orthogonal to the absorption axis direction is significantly reduced. As a result, for example, when exposed to a mechanical impact exceeding the tensile breaking stress in the manufacturing process of the polarizing film, there is a very high possibility that nano slits will occur in the absorption axis direction of the polarizer. Therefore, this invention is especially suitable for the piece protection polarizing film (or polarizing film with an adhesive layer using the same) which employ | adopted the said polarizer.

As the thin polarizer, among the production methods including the step of stretching in the state of a laminate and the step of dyeing, Patent No. 4751486, Patent, in that it can be stretched at a high magnification and the polarization performance can be improved. What is obtained by the manufacturing method including the process of extending | stretching in a boric-acid aqueous solution as described in the 4751481 specification and the patent 4815544 specification is preferable, and it describes especially in the patent 4751481 specification and the patent 4815544 specification. What is obtained by the manufacturing method including the process of extending | stretching in the air auxiliary before extending | stretching in the boric-acid aqueous solution which has this is preferable. These thin polarizers can be obtained by a production method including a step of stretching a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a stretching resin base material in a laminated state and a step of dyeing. With this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching by being supported by the stretching resin substrate.

<Protective film>
As the material constituting the protective film, a material excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is preferable. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene such as polystyrene and acrylonitrile / styrene copolymer (AS resin) And polymers based on polycarbonate and polycarbonate. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or the above Polymer blends and the like can also be mentioned as examples of the polymer forming the protective film.

In addition, 1 or more types of arbitrary appropriate additives may be contained in the protective film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a release agent, a coloring inhibitor, a flame retardant, a nucleating agent, an antistatic agent, a pigment, and a coloring agent. The content of the thermoplastic resin in the protective film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, still more preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. When content of the said thermoplastic resin in a protective film is 50 weight% or less, there exists a possibility that the high transparency etc. which a thermoplastic resin originally has cannot fully be expressed.

As the protective film, a retardation film, a brightness enhancement film, a diffusion film, and the like can also be used. Examples of the retardation film include those having a front retardation of 40 nm or more and / or a retardation having a thickness direction retardation of 80 nm or more. The front phase difference is usually controlled in the range of 40 to 200 nm, and the thickness direction phase difference is usually controlled in the range of 80 to 300 nm. In the case where a retardation film is used as the protective film, the retardation film functions also as a polarizer protective film, so that the thickness can be reduced.

Examples of the retardation film include a birefringent film obtained by uniaxially or biaxially stretching a thermoplastic resin film. The stretching temperature, stretching ratio, and the like are appropriately set depending on the retardation value, film material, and thickness.

The thickness of the protective film can be appropriately determined, but is generally about 1 to 500 μm from the viewpoints of workability such as strength and handleability, and thin layer properties. 1 to 300 μm is particularly preferable, and 5 to 200 μm is more preferable. In particular, in the case of a single protective film, the thickness is preferably 100 μm or less, more preferably 80 μm or less, and further preferably 60 μm or less from the viewpoint of thinning. Moreover, 10 micrometers or more are preferable from a viewpoint of protecting a polarizing film from a break and a fracture | rupture, Furthermore, 20 micrometers or more are preferable. Further, when the thickness of the protective film was V (μm), mechanical stress was applied to the polarizing film in relation to the thickness X (μm) of the polarizer and the thickness Y (μm) of the transparent resin layer. From the viewpoint of suppressing the bending of the polarizer, it is preferable to satisfy 4X ≦ (Y + V), and it is more preferable to satisfy 5X ≦ (Y + V).

In addition, two protective films can be used. From the viewpoint of protecting the polarizing film from breakage and breakage, the two protective films preferably have a total thickness of 10 μm or more, more preferably 20 μm or more, and from the viewpoint of reducing the thickness of the single protective polarizing film. It is preferable to control the total thickness of each protective film to be 100 μm or less.

A functional layer such as a hard coat layer, an antireflection layer, an antisticking layer, a diffusion layer or an antiglare layer can be provided on the surface of the protective film on which the polarizer is not adhered (particularly, the embodiment shown in FIG. 1). In addition, the hard coat layer, the antireflection layer, the antisticking layer, the diffusion layer, the antiglare layer, and other functional layers can be provided on the protective film itself, or can be provided separately from the protective film. it can.

<Intervening layer>
The protective film and the polarizer are laminated via an intervening layer such as an adhesive layer, an adhesive layer, and an undercoat layer (primer layer). At this time, it is desirable that the both are laminated without an air gap by an intervening layer. The protective film and the polarizer are preferably laminated via an adhesive layer.

The adhesive layer is formed with an adhesive. The type of the adhesive is not particularly limited, and various types can be used. The adhesive layer is not particularly limited as long as it is optically transparent. Examples of the adhesive include water-based, solvent-based, hot-melt-based, active energy ray-curable types, and the like. Or an active energy ray hardening-type adhesive agent is suitable.

Examples of water-based adhesives include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex systems, and water-based polyesters. The water-based adhesive is usually used as an adhesive composed of an aqueous solution, and usually contains 0.5 to 60% by weight of solid content. Of these, isocyanate adhesives and polyvinyl alcohol adhesives are preferred. From the isocyanate adhesive, a urethane resin layer is formed as an adhesive layer.

The active energy ray curable adhesive is an adhesive that cures by an active energy ray such as an electron beam or ultraviolet rays (radical curable type, cationic curable type), for example, in an electron beam curable type or an ultraviolet curable type. Can be used. As the active energy ray curable adhesive, for example, a photo radical curable adhesive can be used. When the photo radical curable active energy ray curable adhesive is used as an ultraviolet curable adhesive, the adhesive contains a radical polymerizable compound and a photo polymerization initiator. For example, the radical curable ultraviolet curable adhesive is preferably an ultraviolet curable acrylic resin, and the cationic curable ultraviolet curable adhesive is preferably an ultraviolet curable epoxy resin.

The adhesive coating method is appropriately selected depending on the viscosity of the adhesive and the target thickness. Examples of coating methods include reverse coaters, gravure coaters (direct, reverse and offset), bar reverse coaters, roll coaters, die coaters, bar coaters, rod coaters and the like. In addition, for coating, a method such as a dapping method can be appropriately used.

Further, the thickness of the adhesive layer is preferably 0.1 μm or more and 5 μm or less, and a preferable range can be set depending on the type of the water-based adhesive or the active energy ray-curable adhesive. The thickness of 0.1 μm or more is preferable from the viewpoint of maintaining the adhesive force, and the thickness of 5 μm or less is preferable from the viewpoint of ensuring optical reliability. In the case of using a water-based adhesive or the like, the adhesive is preferably applied so that the finally formed adhesive layer has a thickness of 100 to 300 nm. The thickness of the adhesive layer is more preferably 100 to 250 nm. On the other hand, when an active energy ray curable adhesive is used, the thickness of the adhesive layer is preferably 0.2 to 5 μm. More preferably, it is 0.2 to 2 μm, and still more preferably 0.5 to 1.5 μm.

The adhesive layer preferably has a compressive elastic modulus at 80 ° C. of 0.1 GPa or more and 10 GPa or less in order to suppress penetration cracks while relaxing the force applied to the polarizer. The compression elastic modulus of 0.1 GPa or more is preferable for absorbing cracks and ensuring crack resistance (inhibition of generation of nanoslits and suppression of through cracks), and the compression elastic modulus of 10 GPa or less. This is preferable from the viewpoint of preventing penetration cracks. In particular, when the adhesive layer is formed of an active energy ray-curable adhesive, the compression elastic modulus is preferably 1 GPa or more, and more preferably 3 GPa or more. On the other hand, the compression elastic modulus is preferably 8 GPa or less.

In addition, in laminating | stacking a polarizer and a protective film, an easily bonding layer can be provided between a protective film and an adhesive bond layer. The easy adhesion layer can be formed of, for example, various resins having a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a silicone-based, a polyamide skeleton, a polyimide skeleton, a polyvinyl alcohol skeleton, and the like. These polymer resins can be used alone or in combination of two or more. Moreover, you may add another additive for formation of an easily bonding layer. Specifically, a stabilizer such as a tackifier, an ultraviolet absorber, an antioxidant, and a heat resistance stabilizer may be used.

The easy-adhesion layer is usually provided in advance on a protective film, and the easy-adhesion layer side of the protective film and the polarizer are laminated with an adhesive layer. The easy-adhesion layer is formed by applying and drying a material for forming the easy-adhesion layer on a protective film by a known technique. The material for forming the easy-adhesion layer is usually adjusted as a solution diluted to an appropriate concentration in consideration of the thickness after drying and the smoothness of coating. The thickness of the easy-adhesion layer after drying is preferably 0.01 to 5 μm, more preferably 0.02 to 2 μm, and still more preferably 0.05 to 1 μm. Note that a plurality of easy-adhesion layers can be provided, but also in this case, the total thickness of the easy-adhesion layers is preferably in the above range.

The pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive. Various pressure-sensitive adhesives can be used as the pressure-sensitive adhesive, such as rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, vinyl alkyl ether-based pressure-sensitive adhesives, polyvinylpyrrolidone-based pressure-sensitive adhesives, Examples include acrylamide-based adhesives and cellulose-based adhesives. An adhesive base polymer is selected according to the type of the adhesive. Among the pressure-sensitive adhesives, acrylic pressure-sensitive adhesives are preferably used because they are excellent in optical transparency, exhibit appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and are excellent in weather resistance and heat resistance. The

The undercoat layer (primer layer) is formed to improve the adhesion between the polarizer and the protective film. The material constituting the primer layer is not particularly limited as long as the material exhibits a certain degree of strong adhesion to both the base film and the polyvinyl alcohol-based resin layer. For example, a thermoplastic resin excellent in transparency, thermal stability, stretchability, etc. is used. Examples of the thermoplastic resin include an acrylic resin, a polyolefin resin, a polyester resin, a polyvinyl alcohol resin, or a mixture thereof.

In addition, in the case where at least two protective films are used, each protective film is preferably laminated via an adhesive layer or a pressure-sensitive adhesive layer. The thickness of the adhesive layer is preferably 0.1 μm or more, more preferably 0.2 μm or more from the viewpoint of adhesive strength. On the other hand, the thickness of the adhesive layer is preferably 5 μm or less, and more preferably 2 μm or less from the viewpoint of thinning. Moreover, when using an adhesive for lamination | stacking of each protective film, it is preferable that thickness is 2 micrometers or more from a viewpoint of adhesive force. On the other hand, from the viewpoint of thinning, the thickness of the pressure-sensitive adhesive layer is preferably 20 μm or less.

<Transparent resin layer>
The transparent resin layer is provided on the other surface of the polarizer (the surface on which the protective film is not laminated) in the single-protective polarizing film in which the protective film is provided only on one surface of the polarizer. In the present invention, the transparent resin layer preferably has a compression elastic modulus at 80 ° C. of 0.1 GPa or more. Even if nano slits are generated in the polarizer due to mechanical impact and the nano slits are about to expand in the width direction under a thermal environment, by controlling the compression elastic modulus at 80 ° C. of the transparent resin layer to 0.1 GPa or more, The mechanical holding ability of the transparent resin layer can be maintained even in a thermal environment, and the nano slit can be prevented from spreading in the width direction. The compressive elastic modulus of the transparent resin layer is preferably 0.5 GPa or more, more preferably 2 GPa or more, further 3 GPa or more, further 5 GPa or more, further 6 GPa or more, and further preferably 10 GPa or more. The compression elastic modulus of the transparent resin layer can be adjusted by material selection. In addition, the compression elastic modulus in 80 degreeC of a transparent resin layer is a value measured based on description of an Example.

The thickness of the transparent resin layer is 15 μm or less from the viewpoint of thinning and optical reliability. Further, when the transparent resin layer is thick, curling tends to occur in the piece protective polarizing film after storage. The thickness (Y) of the transparent resin layer is preferably 12 μm or less, more preferably 5 μm or less, and further preferably 1.5 μm or less. On the other hand, the thickness (Y) of the transparent resin layer is preferably 0.2 μm or more, more preferably 0.5 μm or more, and further preferably 0.6 μm or more from the viewpoint of the effect of suppressing the expansion of the nanoslit. Further, it is preferably 0.8 μm or more. The thickness (Y) of the transparent resin layer is controlled so as to satisfy 0.15 ≦ (Y / X) ≦ 3 in relation to the thickness X (μm) of the polarizer.

The transparent resin layer can be formed from a curable forming material containing a curable component. The curable component can be roughly classified into an active energy ray curable type such as an electron beam curable type, an ultraviolet ray curable type, and a visible light curable type, and a thermosetting type. Furthermore, the ultraviolet curable type and the visible light curable type can be classified into a radical polymerization curable type and a cationic polymerization curable type. In the present invention, an active energy ray having a wavelength range of 10 nm to less than 380 nm is expressed as ultraviolet light, and an active energy ray having a wavelength range of 380 nm to 800 nm is expressed as visible light. The radical polymerization curable component can be used as a thermosetting curable component.

≪Radical polymerization curable forming material≫
Examples of the curable component include a radical polymerizable compound. Examples of the radical polymerizable compound include compounds having a radical polymerizable functional group of a carbon-carbon double bond such as a (meth) acryloyl group and a vinyl group. As these curable components, either a monofunctional radical polymerizable compound or a bifunctional or higher polyfunctional radical polymerizable compound can be used. Moreover, these radically polymerizable compounds can be used individually by 1 type or in combination of 2 or more types. As these radically polymerizable compounds, for example, compounds having a (meth) acryloyl group are suitable. In the present invention, (meth) acryloyl means an acryloyl group and / or methacryloyl group, and “(meth)” has the same meaning hereinafter.

≪Monofunctional radical polymerizable compound≫
Examples of the monofunctional radical polymerizable compound include (meth) acrylamide derivatives having a (meth) acrylamide group. The (meth) acrylamide derivative is preferable in terms of ensuring adhesion with the polarizer and having a high polymerization rate and excellent productivity. Specific examples of (meth) acrylamide derivatives include, for example, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N N-alkyl group-containing (meth) acrylamide derivatives such as butyl (meth) acrylamide and N-hexyl (meth) acrylamide; N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N-methylol-N— N-hydroxyalkyl group-containing (meth) acrylamide derivatives such as propane (meth) acrylamide; N-aminoalkyl group-containing (meth) acrylamide derivatives such as aminomethyl (meth) acrylamide and aminoethyl (meth) acrylamide; N-methoxymethyl N-alkoxy group-containing (meth) acrylamide derivatives such as acrylamide and N-ethoxymethylacrylamide; N-mercaptoalkyl group-containing (meth) acrylamide derivatives such as mercaptomethyl (meth) acrylamide and mercaptoethyl (meth) acrylamide; It is done. Examples of the heterocyclic-containing (meth) acrylamide derivative in which the nitrogen atom of the (meth) acrylamide group forms a heterocyclic ring include, for example, N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, N-acryloylpyrrolidine. Etc.

Among the (meth) acrylamide derivatives, an N-hydroxyalkyl group-containing (meth) acrylamide derivative is preferable from the viewpoint of adhesion to a polarizer, and N-hydroxyethyl (meth) acrylamide is particularly preferable.

In addition, examples of the monofunctional radical polymerizable compound include various (meth) acrylic acid derivatives having a (meth) acryloyloxy group. Specifically, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, 2-methyl-2-nitropropyl (meth) acrylate, n-butyl ( (Meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, t-pentyl (meth) acrylate, 3-pentyl (meth) acrylate, 2,2-dimethylbutyl (meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 4-methyl-2-propylpentyl ( (Meth) acrylate, n-o Tadeshiru (meth) (meth) acrylic acid (1-20 carbon atoms) such as acrylates alkyl esters.

Examples of the (meth) acrylic acid derivative include cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate and cyclopentyl (meth) acrylate;
Aralkyl (meth) acrylates such as benzyl (meth) acrylate;
2-isobornyl (meth) acrylate, 2-norbornylmethyl (meth) acrylate, 5-norbornen-2-yl-methyl (meth) acrylate, 3-methyl-2-norbornylmethyl (meth) acrylate, dicyclo Polycyclic (meth) acrylates such as pentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and the like;
2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) Examples thereof include alkoxy groups such as acrylates and alkylphenoxypolyethylene glycol (meth) acrylates or phenoxy group-containing (meth) acrylates.

Examples of the (meth) acrylic acid derivative include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4- Hydroxyalkyl (meth) acrylates such as hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, etc. And hydroxyl groups such as [4- (hydroxymethyl) cyclohexyl] methyl acrylate, cyclohexanedimethanol mono (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, etc. Meth) acrylate;
Epoxy group-containing (meth) acrylates such as glycidyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate glycidyl ether;
2,2,2-trifluoroethyl (meth) acrylate, 2,2,2-trifluoroethylethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, octafluoropentyl (meth) ) Halogen-containing (meth) acrylates such as acrylate, heptadecafluorodecyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate;
Alkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate;
3-Oxetanylmethyl (meth) acrylate, 3-methyl-oxetanylmethyl (meth) acrylate, 3-ethyl-oxetanylmethyl (meth) acrylate, 3-butyl-oxetanylmethyl (meth) acrylate, 3-hexyloxetanylmethyl (meta) ) Oxetane group-containing (meth) acrylates such as acrylates;
(Meth) acrylates having a heterocyclic ring such as tetrahydrofurfuryl (meth) acrylate, butyrolactone (meth) acrylate, neopentyl glycol (meth) acrylic acid adducts such as hydroxypivalate, p-phenylphenol (meth) acrylate, etc. Can be mentioned.

Also, examples of the monofunctional radically polymerizable compound include carboxyl group-containing monomers such as (meth) acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid.

Examples of the monofunctional radical polymerizable compound include lactam vinyl monomers such as N-vinyl pyrrolidone, N-vinyl-ε-caprolactam, and methyl vinyl pyrrolidone; vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piperazine, vinyl pyrazine, Examples thereof include vinyl monomers having a nitrogen-containing heterocyclic ring such as vinyl pyrrole, vinyl imidazole, vinyl oxazole and vinyl morpholine.

Also, as the monofunctional radically polymerizable compound, a radically polymerizable compound having an active methylene group can be used. The radical polymerizable compound having an active methylene group is a compound having an active methylene group having an active double bond group such as a (meth) acryl group at the terminal or in the molecule. Examples of the active methylene group include an acetoacetyl group, an alkoxymalonyl group, and a cyanoacetyl group. The active methylene group is preferably an acetoacetyl group. Specific examples of the radical polymerizable compound having an active methylene group include 2-acetoacetoxyethyl (meth) acrylate, 2-acetoacetoxypropyl (meth) acrylate, 2-acetoacetoxy-1-methylethyl (meth) acrylate, and the like. Acetoacetoxyalkyl (meth) acrylate; 2-ethoxymalonyloxyethyl (meth) acrylate, 2-cyanoacetoxyethyl (meth) acrylate, N- (2-cyanoacetoxyethyl) acrylamide, N- (2-propionylacetoxybutyl) Examples include acrylamide, N- (4-acetoacetoxymethylbenzyl) acrylamide, and N- (2-acetoacetylaminoethyl) acrylamide. The radical polymerizable compound having an active methylene group is preferably acetoacetoxyalkyl (meth) acrylate.

≪Polyfunctional radical polymerizable compound≫
Examples of the bifunctional or higher polyfunctional radical polymerizable compound include tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9 -Nonanediol di (meth) acrylate, 1,10-decanediol diacrylate, 2-ethyl-2-butylpropanediol di (meth) acrylate, bisphenol A di (meth) acrylate, bisphenol A ethylene oxide adduct di (meth) ) Acrylate, bisphenol A propylene oxide adduct di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neopentyl glycol di (meth) acrylate, tricyclodecane dimethanol di (meth) Acryte, cyclic trimethylolpropane formal (meth) acrylate, dioxane glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta Esterified products of (meth) acrylic acid and polyhydric alcohols such as (meth) acrylate, dipentaerythritol hexa (meth) acrylate, EO-modified diglycerin tetra (meth) acrylate, 9,9-bis [4- (2- (Meth) acryloyloxyethoxy) phenyl] fluorene. Specific examples include Aronix M-220, M-306 (manufactured by Toagosei Co., Ltd.), light acrylate 1,9ND-A (manufactured by Kyoeisha Chemical Co., Ltd.), light acrylate DGE-4A (manufactured by Kyoeisha Chemical Co., Ltd.), light acrylate DCP- A (manufactured by Kyoeisha Chemical Co., Ltd.), SR-531 (manufactured by Sartomer), CD-536 (manufactured by Sartomer) and the like. Moreover, various epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates, various (meth) acrylate monomers, and the like are included as necessary.

The radical polymerizable compound is preferably used in combination with a monofunctional radical polymerizable compound and a polyfunctional radical polymerizable compound from the viewpoint of achieving both adhesion to the polarizer and optical durability. Usually, it is preferable to use a combination of 3 to 80% by weight of the monofunctional radical polymerizable compound and 20 to 97% by weight of the polyfunctional radical polymerizable compound with respect to 100% by weight of the radical polymerizable compound.

≪Aspects of radical polymerization curable forming material≫
The radical polymerization curable forming material can be used as an active energy ray curable forming material or a thermosetting forming material. When using an electron beam or the like for the active energy ray, the active energy ray curable forming material does not need to contain a photopolymerization initiator, but when using ultraviolet rays or visible light for the active energy ray, It preferably contains a photopolymerization initiator. On the other hand, when the curable component is used as a thermosetting component, the forming material preferably contains a thermal polymerization initiator.

≪Photopolymerization initiator≫
The photopolymerization initiator in the case of using the radical polymerizable compound is appropriately selected depending on the active energy ray. In the case of curing by ultraviolet light or visible light, a photopolymerization initiator for ultraviolet light or visible light cleavage is used. Examples of the photopolymerization initiator include benzophenone compounds such as benzyl, benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone; 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2 -Propyl) ketone, aromatic ketone compounds such as α-hydroxy-α, α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, α-hydroxycyclohexyl phenyl ketone; methoxyacetophenone, 2,2-dimethoxy- Acetophenone compounds such as 2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1- [4- (methylthio) -phenyl] -2-morpholinopropane-1; benzoin methyl ether; Benzoin ethyl ether, benzoin Benzoin ether compounds such as isopropyl ether, benzoin butyl ether and anisoin methyl ether; aromatic ketal compounds such as benzyldimethyl ketal; aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride; 1-phenone-1 , 1-propanedione-2- (o-ethoxycarbonyl) oxime, etc .; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone Thioxanthone compounds such as Son, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone; camphorquinone; halogenated ketone; Inokishido; and acyl phospholipase diisocyanate, and the like.

The blending amount of the photopolymerization initiator is 20 parts by weight or less with respect to 100 parts by weight of the total amount of the curable component (radical polymerizable compound). The blending amount of the photopolymerization initiator is preferably 0.01 to 20 parts by weight, more preferably 0.05 to 10 parts by weight, and further preferably 0.1 to 5 parts by weight.

Moreover, when using the curable forming material for polarizing films of the present invention in a visible light curable type containing a radical polymerizable compound as a curable component, a photopolymerization initiator that is particularly sensitive to light of 380 nm or more is used. It is preferable to use it. A photopolymerization initiator that is highly sensitive to light of 380 nm or more will be described later.

As said photoinitiator, the compound represented by following General formula (1);

(Wherein R ¹ and R ² represent —H, —CH ₂ CH ₃ , —iPr or Cl, and R ¹ and R ² may be the same or different), respectively, or a general formula ( It is preferable to use together the compound represented by 1) and a photopolymerization initiator that is highly sensitive to light of 380 nm or more, which will be described later. When the compound represented by the general formula (1) is used, the adhesion is excellent as compared with the case where a photopolymerization initiator having high sensitivity to light of 380 nm or more is used alone. Among the compounds represented by the general formula (1), diethylthioxanthone in which R ¹ and R ² are —CH ₂ CH ₃ is particularly preferable. The composition ratio of the compound represented by the general formula (1) in the forming material is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the total amount of the curable component, and preferably 0.5 to 4 parts. More preferred are parts by weight, and even more preferred is 0.9 to 3 parts by weight.

Further, it is preferable to add a polymerization initiation assistant as necessary. Examples of polymerization initiators include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, etc. Among them, ethyl 4-dimethylaminobenzoate is particularly preferable. When a polymerization initiation assistant is used, its addition amount is usually 0 to 5 parts by weight, preferably 0 to 4 parts by weight, most preferably 0 to 3 parts by weight, based on 100 parts by weight of the total amount of the curable component. is there.

Further, a known photopolymerization initiator can be used in combination as necessary. Since the protective film having UV absorbing ability does not transmit light of 380 nm or less, it is preferable to use a photopolymerization initiator that is highly sensitive to light of 380 nm or more as the photopolymerization initiator. Specifically, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine Oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole) 1-yl) -phenyl) titanium and the like.

In particular, as a photopolymerization initiator, in addition to the photopolymerization initiator of the general formula (1), a compound represented by the following general formula (2);

Wherein R ³ , R ⁴ and R ⁵ represent —H, —CH ₃ , —CH ₂ CH ₃ , —iPr or Cl, and R ³ , R ⁴ and R ⁵ may be the same or different. It is preferable to use it. As the compound represented by the general formula (2), 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (trade name: IRGACURE907 manufacturer: BASF) which is also a commercial product is suitable. Can be used. In addition, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (trade name: IRGACURE369 manufacturer: BASF), 2- (dimethylamino) -2-[(4-methylphenyl) Methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone (trade name: IRGACURE379 manufacturer: BASF) is preferred because of its high sensitivity.

<Radical polymerizable compound having active methylene group and radical polymerization initiator having hydrogen abstraction action>
In the active energy ray curable forming material, when a radical polymerizable compound having an active methylene group is used as the radical polymerizable compound, it is preferably used in combination with a radical polymerization initiator having a hydrogen abstraction function.

Examples of the radical polymerization initiator having a hydrogen abstracting action include thioxanthone radical polymerization initiators and benzophenone radical polymerization initiators. The radical polymerization initiator is preferably a thioxanthone radical polymerization initiator. Examples of the thioxanthone radical polymerization initiator include compounds represented by the above general formula (1). Specific examples of the compound represented by the general formula (1) include thioxanthone, dimethylthioxanthone, diethylthioxanthone, isopropylthioxanthone, and chlorothioxanthone. Among the compounds represented by the general formula (1), diethylthioxanthone in which R ¹ and R ² are —CH ₂ CH ₃ is particularly preferable.

In the active energy ray-curable forming material, when the radical polymerizable compound having an active methylene group and a radical polymerization initiator having a hydrogen abstraction function are contained, when the total amount of the curable component is 100% by weight, It is preferable to contain 1 to 50% by weight of the radical polymerizable compound having an active methylene group and 0.1 to 10 parts by weight of the radical polymerization initiator with respect to 100 parts by weight of the total amount of the curable component.

≪Thermal polymerization initiator≫
As the thermal polymerization initiator, those in which polymerization does not start by thermal cleavage when the adhesive layer is formed are preferable. For example, as the thermal polymerization initiator, those having a 10-hour half-life temperature of 65 ° C. or higher, more preferably 75 to 90 ° C. are preferable. The half-life is an index representing the decomposition rate of the polymerization initiator and refers to the time until the remaining amount of the polymerization initiator is halved. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in the manufacturer catalog, for example, “Organic peroxide catalog 9th edition by Nippon Oil & Fats Co., Ltd.” (May 2003) ".

Examples of the thermal polymerization initiator include lauroyl peroxide (10 hour half-life temperature: 64 ° C.), benzoyl peroxide (10 hour half-life temperature: 73 ° C.), 1,1-bis (t-butylperoxy) -3. , 3,5-trimethylcyclohexane (10-hour half-life temperature: 90 ° C.), di (2-ethylhexyl) peroxydicarbonate (10-hour half-life temperature: 49 ° C.), di (4-t-butylcyclohexyl) Peroxydicarbonate, di-sec-butylperoxydicarbonate (10-hour half-life temperature: 51 ° C.), t-butyl peroxyneodecanoate (10-hour half-life temperature: 48 ° C.), t-hexyl peroxy Pivalate, t-butylperoxypivalate, dilauroyl peroxide (10 hour half-life temperature: 64 ° C.), di-n-

octanoyl peroxide

1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (10-hour half-life temperature: 66 ° C.), di (4-methylbenzoyl) peroxide, dibenzoyl peroxide (half-hour 10 hours) Organic peroxide such as t-butyl peroxyisobutyrate (10-hour half-life temperature: 81 ° C.), 1,1-di (t-hexylperoxy) cyclohexane, and the like.

Examples of the thermal polymerization initiator include 2,2′-azobisisobutyronitrile (10 hour half-life temperature: 67 ° C.), 2,2′-azobis (2-methylbutyronitrile) (10 hours). And azo compounds such as 1,1-azobis-cyclohexane-1-carbonitrile (10 hour half-life temperature: 87 ° C.).

The blending amount of the thermal polymerization initiator is 0.01 to 20 parts by weight with respect to 100 parts by weight of the total amount of the curable component (radical polymerizable compound). The blending amount of the thermal polymerization initiator is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 3 parts by weight.

≪Cation polymerization curable forming material≫
Examples of the curable component of the cationic polymerization curable forming material include compounds having an epoxy group or an oxetanyl group. The compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various generally known curable epoxy compounds can be used. As a preferable epoxy compound, a compound having at least two epoxy groups and at least one aromatic ring in the molecule (aromatic epoxy compound), or at least two epoxy groups in the molecule, at least one of them. Examples thereof include a compound (alicyclic epoxy compound) formed between two adjacent carbon atoms constituting an alicyclic ring.

<Other ingredients>
The curable forming material according to the present invention preferably contains the following components.

<Acrylic oligomer>
The active energy ray-curable forming material according to the present invention can contain an acrylic oligomer obtained by polymerizing a (meth) acrylic monomer, in addition to the curable component related to the radical polymerizable compound. By containing an acrylic oligomer in the active energy ray curable forming material, curing shrinkage when irradiating and curing the active energy ray to the transparent resin layer is reduced, and the transparent resin layer and the polarizer are attached. Interfacial stress with the body can be reduced. As a result, it is possible to suppress a decrease in adhesiveness between the adhesive layer and the adherend. In order to sufficiently suppress the curing shrinkage, the content of the acrylic oligomer is preferably 20 parts by weight or less and more preferably 15 parts by weight or less with respect to 100 parts by weight of the total amount of the curable component. preferable. When the content of the acrylic oligomer in the forming material is too large, the reaction rate when the forming material is irradiated with active energy rays is drastically reduced, which may result in poor curing. On the other hand, the acrylic oligomer is preferably contained in an amount of 3 parts by weight or more, more preferably 5 parts by weight or more, based on 100 parts by weight of the total amount of the curable component.

The active energy ray-curable forming material preferably has a low viscosity in consideration of workability and uniformity during coating, and thus an acrylic oligomer obtained by polymerizing a (meth) acrylic monomer also has a low viscosity. It is preferable. The acrylic oligomer having a low viscosity and capable of preventing curing shrinkage of the transparent resin layer preferably has a weight average molecular weight (Mw) of 15000 or less, more preferably 10,000 or less, and particularly preferably 5000 or less. preferable. On the other hand, in order to sufficiently suppress the curing shrinkage of the transparent resin layer, the weight average molecular weight (Mw) of the acrylic oligomer is preferably 500 or more, more preferably 1000 or more, and 1500 or more. Is particularly preferred. Specific examples of the (meth) acrylic monomer constituting the acrylic oligomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, 2-methyl- 2-nitropropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, S-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, t-pentyl (Meth) acrylate, 3-pentyl (meth) acrylate, 2,2-dimethylbutyl (meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl ( (Meth) acrylate (Meth) acrylic acid (carbon number 1-20) alkyl esters such as 4-methyl-2-propylpentyl (meth) acrylate and N-octadecyl (meth) acrylate, and further, for example, cycloalkyl (meth) acrylate (for example, Cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, etc.), aralkyl (meth) acrylate (eg benzyl (meth) acrylate, etc.), polycyclic (meth) acrylate (eg 2-isobornyl (meth) acrylate, 2 -Norbornylmethyl (meth) acrylate, 5-norbornen-2-yl-methyl (meth) acrylate, 3-methyl-2-norbornylmethyl (meth) acrylate, etc.), hydroxyl group-containing (meth) acrylic acid ester (E.g. hydro (Methyl) acrylate, 2-hydroxypropyl (meth) acrylate, 2,3-dihydroxypropylmethyl-butyl (meth) methacrylate, etc.), alkoxy group or phenoxy group-containing (meth) acrylic acid esters (2-methoxyethyl ( (Meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, etc.), epoxy Group-containing (meth) acrylic acid esters (for example, glycidyl (meth) acrylate), halogen-containing (meth) acrylic acid esters (for example, 2,2,2-trifluoroethyl (meth) acrylate, 2,2, 2- Trifluoroethylethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate, etc.), alkylaminoalkyl (meth) An acrylate (for example, dimethylaminoethyl (meth) acrylate etc.) etc. are mentioned. These (meth) acrylates can be used alone or in combination of two or more. Specific examples of the acrylic oligomer include “ARUFON” manufactured by Toagosei Co., Ltd., “Act Flow” manufactured by Soken Chemical Co., Ltd., “JONCRYL” manufactured by BASF Japan.

<Photo acid generator>
The active energy ray-curable forming material may contain a photoacid generator. When the active energy ray-curable forming material contains a photoacid generator, the water resistance and durability of the transparent resin layer can be drastically improved as compared with the case where no photoacid generator is contained. The photoacid generator can be represented by the following general formula (3).

General formula (3)

(However, L ⁺ represents any onium cation. X ⁻ represents PF6 ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , SbCl ₆ ⁻ , BiCl ₅ ⁻ , SnCl ₆ ⁻ , ClO ₄ ⁻ , dithiocarbamate. Represents a counter anion selected from the group consisting of an anion and SCN-)

Specific examples of preferred onium salts constituting the photoacid generator include PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , SbCl ₆ ⁻ , BiCl ₅ ⁻ , SnCl ₆ ⁻ , ClO ₄ ⁻ , dithiocarbamate anion, SCN ^−. It is an onium salt comprising an anion selected from more.

Specifically, “Syracure UVI-6922”, “Syracure UVI-6974” (manufactured by Dow Chemical Japan Co., Ltd.), “Adekaoptomer SP150”, “Adekaoptomer SP152”, “Adekaoptomer” “SP170”, “Adekaoptomer SP172” (manufactured by ADEKA Corporation), “IRGACURE250” (manufactured by Ciba Specialty Chemicals), “CI-5102”, “CI-2855” (manufactured by Nippon Soda Co., Ltd.), “Sun-Aid SI-60L”, “Sun-Aid SI-80L”, “Sun-Aid SI-100L”, “Sun-Aid SI-110L”, “Sun-Aid SI-180L” (manufactured by Sanshin Chemical Co., Ltd.), “CPI-100P”, "CPI-100A" (San Apro Co., Ltd.), "WPI-06 "," WPI-113 "," WPI-116 "," WPI-041 "," WPI-044 "," WPI-054 "," WPI-055 "," WPAG-281 "," WPAG-567 " “WPAG-596” (manufactured by Wako Pure Chemical Industries, Ltd.) is a preferred specific example of the photoacid generator.

The content of the photoacid generator is 10 parts by weight or less, preferably 0.01 to 10 parts by weight, and preferably 0.05 to 5 parts by weight with respect to 100 parts by weight of the total amount of the curable component. More preferred is 0.1 to 3 parts by weight.

≪Photo cationic polymerization initiator≫
The cationic polymerization curable forming material contains the epoxy compound and the oxetane compound described above as the curable component, and both of these are cured by cationic polymerization, and therefore, a photocationic polymerization initiator is blended therein. This cationic photopolymerization initiator generates a cationic species or a Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, and starts a polymerization reaction of an epoxy group or an oxetanyl group.

The formation of the transparent resin layer by the curable forming material is performed by coating the curable forming material on the surface of the polarizer and then curing.

The polarizer may be subjected to a surface modification treatment before coating the curable forming material. Specific examples of the treatment include corona treatment, plasma treatment, and saponification treatment.

The coating method of the curable forming material is appropriately selected depending on the viscosity of the curable forming material and the target thickness. Examples of coating methods include reverse coaters, gravure coaters (direct, reverse and offset), bar reverse coaters, roll coaters, die coaters, bar coaters, rod coaters and the like. In addition, for coating, a method such as a dapping method can be appropriately used.

<Curing of forming material>
The curable forming material is used as an active energy ray curable forming material or a thermosetting forming material. The active energy ray curable forming material can be used in an electron beam curable type, an ultraviolet curable type, or a visible light curable type. The aspect of the curable forming material is preferably an active energy ray curable forming material rather than a thermosetting forming material from the viewpoint of productivity, and moreover, the active energy ray curable forming material is a visible light curable forming material. It is preferable from the viewpoint of productivity.

≪Active energy ray curing type≫
In the active energy ray curable forming material, after applying the active energy ray curable forming material to the polarizer, the active energy ray (electron beam, ultraviolet ray, visible light, etc.) is irradiated, and the active energy ray curable forming material is applied. Curing to form a transparent resin layer. The irradiation direction of active energy rays (electron beam, ultraviolet ray, visible light, etc.) can be irradiated from any appropriate direction. Preferably, it irradiates from the transparent resin layer side.

≪Electron beam curing type≫
In the electron beam curable type, any appropriate condition can be adopted as the electron beam irradiation condition as long as the active energy ray curable forming material can be cured. For example, in the electron beam irradiation, the acceleration voltage is preferably 5 kV to 300 kV, and more preferably 10 kV to 250 kV. If the acceleration voltage is less than 5 kV, the electron beam may not reach the deepest part of the transparent resin layer and may be insufficiently cured. If the acceleration voltage exceeds 300 kV, the penetration force through the sample is too strong, and a protective film or polarizer May cause damage. The irradiation dose is 5 to 100 kGy, more preferably 10 to 75 kGy. When the irradiation dose is less than 5 kGy, the adhesive is insufficiently cured, and when it exceeds 100 kGy, the protective film and the polarizer are damaged, resulting in a decrease in mechanical strength and yellowing, thereby obtaining predetermined optical characteristics. Can not.

The electron beam irradiation is usually performed in an inert gas, but if necessary, it may be performed in the atmosphere or under a condition where a little oxygen is introduced.

≪Ultraviolet curing type, visible light curing type≫
In the method for producing a polarizing film according to the present invention, active energy rays containing visible light having a wavelength range of 380 nm to 450 nm, particularly active energy rays having the largest irradiation amount of visible light having a wavelength range of 380 nm to 450 nm are used as active energy rays. It is preferable. As the active energy ray according to the present invention, a gallium-encapsulated metal halide lamp and an LED light source that emits light in the wavelength range of 380 to 440 nm are preferable. Or low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, incandescent lamp, xenon lamp, halogen lamp, carbon arc lamp, metal halide lamp, fluorescent lamp, tungsten lamp, gallium lamp, excimer laser or sunlight A light source including visible light can be used, and ultraviolet light having a wavelength shorter than 380 nm can be blocked using a band pass filter.

≪Thermosetting type≫
On the other hand, in a thermosetting type forming material, after bonding a polarizer and a protective film, by heating, polymerization is started by a thermal polymerization initiator to form a cured product layer. The heating temperature is set according to the thermal polymerization initiator, but is about 60 to 200 ° C., preferably 80 to 150 ° C.

Further, as a material for forming the transparent resin layer, for example, a cyanoacrylate-based forming material, an epoxy-based forming material, or an isocyanate-based forming material can be used.

Examples of the cyanoacrylate-based forming material include alkyl-α-cyanoacrylates such as methyl-α-cyanoacrylate, ethyl-α-cyanoacrylate, butyl-α-cyanoacrylate, octyl-α-cyanoacrylate, and cyclohexyl-α-. And cyanoacrylate and methoxy-α-cyanoacrylate. As the cyanoacrylate-based forming material, for example, those used as a cyanoacrylate-based adhesive can be used.

The epoxy-based forming material may be used alone as an epoxy resin or may contain an epoxy curing agent. When the epoxy resin is used alone, it is cured by adding a photopolymerization initiator and irradiating active energy rays. When an epoxy curing agent is added as an epoxy-based forming material, for example, those used as an epoxy-based adhesive can be used. The usage form of the epoxy-based forming material can be used as a one-component type containing an epoxy resin and its curing agent, but it is used as a two-component type in which a curing agent is blended with the epoxy resin. Epoxy-based forming materials are usually used as solutions. The solution may be a solvent system or an aqueous system such as an emulsion, a colloidal dispersion, or an aqueous solution.

Examples of the epoxy resin include various compounds containing two or more epoxy groups in the molecule. For example, bisphenol type epoxy resin, aliphatic type epoxy resin, aromatic type epoxy resin, halogenated bisphenol type epoxy resin, biphenyl And epoxy resin. Moreover, although an epoxy resin can be suitably determined according to an epoxy equivalent and the number of functional groups, the epoxy equivalent of 500 or less is used suitably from a durable viewpoint.

The curing agent for the epoxy resin is not particularly limited, and various types such as phenol resin type, acid anhydride type, carboxylic acid type, and polyamine type can be used. As the phenol resin-based curing agent, for example, phenol novolak resin, bisphenol novolak resin, xylylene phenol resin, cresol novolak resin, or the like is used. Examples of acid anhydride-based curing agents include: maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, succinic anhydride, and the like. Examples of carboxylic acid-based curing agents include carboxylic acids such as pyromellitic acid and trimellitic acid. Examples thereof include block carboxylic acids added with acids and vinyl ether. Moreover, as an epoxy-type two-component formation material, what consists of two liquids of an epoxy resin and a polythiol, what consists of two liquids of an epoxy resin and polyamide, etc. can be used, for example.

The blending amount of the curing agent varies depending on the equivalent to the epoxy resin, but is preferably 30 to 70 parts by weight, more preferably 40 to 60 parts by weight with respect to 100 parts by weight of the epoxy resin.

In addition to the epoxy resin and its curing agent, various curing accelerators can be used for the epoxy-based forming material. Examples of the curing accelerator include various imidazole compounds and derivatives thereof, dicyandiamide, and the like.

Examples of the isocyanate-based forming material include those used as a crosslinking agent in the formation of the pressure-sensitive adhesive layer. As the isocyanate-based crosslinking agent, a compound having at least two isocyanate groups can be used. For example, the polyisocyanate compound can be used as an isocyanate-based forming material. Specifically, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, 1,3-bisisocyanatomethylcyclohexane, hexamethylene diisocyanate, tetramethylxylylene diisocyanate, m-isopropenyl-α, α-dimethylbenzyl isocyanate, methylene bis 4-phenyl isocyanate, p-phenylene diisocyanate or their dimers, trimers such as isocyanuric acid tris (6-inocyanate hexyl), biuret, trimethylolpropane, etc. Examples include those reacted with polyhydric alcohols and polyhydric amines. As the isocyanate-based crosslinking agent, those having three or more isocyanate groups such as isocyanuric acid tris (6-inocyanate hexyl) are preferable. As an isocyanate type formation material, what is used as an isocyanate type adhesive agent is mention | raise | lifted, for example.

Among the isocyanate-based forming materials, in the present invention, it is preferable to use those having a rigid structure in which a cyclic structure (benzene ring, cyanurate ring, isocyanurate ring, etc.) accounts for a large proportion in the structure. As the isocyanate-based forming material, for example, trimethylolpropane-tri-tolylene isocyanate, tris (hexamethylene isocyanate) isocyanurate and the like are preferably used.

In addition, the said isocyanate type crosslinking agent can also use what provided the protective group to the terminal isocyanate group. Protecting groups include oximes and lactams. In the case where the isocyanate group is protected, the protecting group is dissociated from the isocyanate group by heating, and the isocyanate group reacts.

Further, a reaction catalyst can be used to increase the reactivity of the isocyanate group. The reaction catalyst is not particularly limited, but a tin-based catalyst or an amine-based catalyst is suitable. The reaction catalyst can use 1 type (s) or 2 or more types. The amount of the reaction catalyst used is usually 5 parts by weight or less with respect to 100 parts by weight of the isocyanate-based crosslinking agent. When the amount of the reaction catalyst is large, the crosslinking reaction rate increases and foaming of the forming material occurs. Even if the forming material after foaming is used, sufficient adhesion cannot be obtained. Usually, when a reaction catalyst is used, it is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 4 parts by weight.

As the tin-based catalyst, both inorganic and organic catalysts can be used, but an organic catalyst is preferred. Examples of the inorganic tin-based catalyst include stannous chloride and stannic chloride. The organic tin-based catalyst is preferably one having at least one organic group such as an aliphatic group or alicyclic group having a skeleton such as a methyl group, an ethyl group, an ether group or an ester group. Examples include tetra-n-butyltin, tri-n-butyltin acetate, n-butyltin trichloride, trimethyltin hydroxide, dimethyltin dichloride, dibutyltin dilaurate and the like.

The amine catalyst is not particularly limited. For example, those having at least one organic group such as an alicyclic group such as quinoclidine, amidine, and diazabicycloundecene are preferable. In addition, examples of the amine catalyst include triethylamine. Examples of reaction catalysts other than the above include cobalt naphthenate and benzyltrimethylammonium hydroxide.

The isocyanate-based forming material is usually used as a solution. The solution may be a solvent system or an aqueous system such as an emulsion, a colloidal dispersion, or an aqueous solution. The organic solvent is not particularly limited as long as the components constituting the forming material are uniformly dissolved. Examples of the organic solvent include toluene, methyl ethyl ketone, ethyl acetate and the like. In the case of using an aqueous system, for example, alcohols such as n-butyl alcohol and isopropyl alcohol and ketones such as acetone can be blended. In the case of using an aqueous system, a dispersant is used, or an isocyanate-based crosslinking agent, a functional group having low reactivity with an isocyanate group such as a carboxylate, a sulfonate, or a quaternary ammonium salt, or an aqueous dispersion such as polyethylene glycol. It can carry out by introduce | transducing a sex component.

The formation of the transparent resin layer by the cyanoacrylate-based forming material, the epoxy-based forming material, or the isocyanate-based forming material can be appropriately selected according to the type of the forming material, but is usually about 30 to 100 ° C., The drying is preferably performed at 50 to 80 ° C. for about 0.5 to 15 minutes. In the case of a cyanoacrylate-based forming material, since the curing is fast, the transparent resin layer can be formed in a time shorter than the above time.

The transparent resin layer may be formed from a forming material that does not contain a curable component. For example, the transparent resin layer may be formed from a forming material that contains the polyvinyl alcohol-based resin as a main component. The polyvinyl alcohol resin forming the transparent resin layer may be the same as or different from the polyvinyl alcohol resin contained in the polarizer as long as it is a “polyvinyl alcohol resin”.

Examples of the polyvinyl alcohol resin include polyvinyl alcohol. Polyvinyl alcohol is obtained by saponifying polyvinyl acetate. Examples of the polyvinyl alcohol-based resin include a saponified product of a copolymer of vinyl acetate and a monomer having copolymerizability. When the copolymerizable monomer is ethylene, an ethylene-vinyl alcohol copolymer is obtained. Examples of the copolymerizable monomer include unsaturated carboxylic acids such as (anhydrous) maleic acid, fumaric acid, crotonic acid, itaconic acid, (meth) acrylic acid, and esters thereof; ethylene, propylene, and the like. α-olefin, (meth) allylsulfonic acid (soda), sulfonic acid soda (monoalkylmalate), disulfonic acid soda alkylmalate, N-methylolacrylamide, acrylamide alkylsulfonic acid alkali salt, N-vinylpyrrolidone, N- Examples include vinyl pyrrolidone derivatives. These polyvinyl alcohol resins can be used alone or in combination of two or more. Polyvinyl alcohol obtained by saponifying polyvinyl acetate is preferable from the viewpoint of controlling the heat of crystal fusion of the transparent resin layer to 30 mj / mg or more and satisfying heat and moisture resistance and water resistance.

The degree of saponification of the polyvinyl alcohol resin can be, for example, 95% or more, and the heat of crystal melting of the transparent resin layer is controlled to 30 mj / mg or more to satisfy the heat and moisture resistance and water resistance. Therefore, the degree of saponification is preferably 99.0% or more, and more preferably 99.7% or more. The degree of saponification represents the proportion of units that are actually saponified to vinyl alcohol units among the units that can be converted to vinyl alcohol units by saponification, and the residue is a vinyl ester unit. The degree of saponification can be determined according to JIS K 6726-1994.

The average degree of polymerization of the polyvinyl alcohol-based resin can be, for example, 500 or more, and the heat of crystal melting of the transparent resin layer is controlled to 30 mj / mg or more to satisfy the moisture and heat resistance and water resistance. From the viewpoint, the average degree of polymerization is preferably 1000 or more, more preferably 1500 or more, and further preferably 2000 or more. The average degree of polymerization of the polyvinyl alcohol resin is measured according to JIS-K6726.

As the polyvinyl alcohol resin, a modified polyvinyl alcohol resin having a hydrophilic functional group in the side chain of the polyvinyl alcohol or a copolymer thereof can be used. Examples of the hydrophilic functional group include an acetoacetyl group and a carbonyl group. In addition, modified polyvinyl alcohol obtained by acetalization, urethanization, etherification, grafting, phosphoric esterification or the like of a polyvinyl alcohol resin can be used.

The forming material containing the polyvinyl alcohol-based resin as a main component can contain a curable component (crosslinking agent) and the like. The proportion of the polyvinyl alcohol-based resin in the transparent resin layer or the forming material (solid content) is preferably 80% by weight or more, more preferably 90% by weight or more, and further preferably 95% by weight or more. However, it is preferable that the forming material does not contain a curable component (crosslinking agent) from the viewpoint of easily controlling the heat of crystal fusion of the transparent resin layer to 30 mj / mg or more.

As the crosslinking agent, a compound having at least two functional groups having reactivity with the polyvinyl alcohol resin can be used. For example, alkylenediamine having two alkylene groups and two amino groups such as ethylenediamine, triethylenediamine, hexamethylenediamine; tolylene diisocyanate, hydrogenated tolylene diisocyanate, trimethylolpropane tolylene diisocyanate adduct, triphenylmethane triisocyanate, methylene bis (4-Phenylmethane triisocyanate, isophorone diisocyanate and isocyanates such as ketoxime block product or phenol block product thereof; ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin di or triglycidyl ether, 1,6-hexane Diol diglycidyl ether, trimethylolpropane triglycidyl ether, di Epoxies such as ricidylaniline and diglycidylamine; monoaldehydes such as formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde; Dialdehydes; amino-formaldehyde resins such as methylolurea, methylolmelamine, alkylated methylolurea, alkylated methylolated melamine, acetoguanamine, condensate of benzoguanamine and formaldehyde; adipic acid dihydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, Succinic acid dihydrazide, glutaric acid dihydrazide, isophthalic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide Examples thereof include dicarboxylic acid dihydrazides such as fumaric acid dihydrazide and itaconic acid dihydrazide; and water-soluble dihydrazines such as ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine and butylene-1,4-dihydrazine. Of these, amino-formaldehyde resins and water-soluble dihydrazine are preferred, and the amino-formaldehyde resin is preferably a compound having a methylol group, particularly methylol melamine, which is a compound having a methylol group.

Although the said sclerosing | hardenable component (crosslinking agent) can be used from a viewpoint of water resistance improvement, the ratio is 20 weight part or less, 10 weight part or less, 5 weight part with respect to 100 weight part of polyvinyl alcohol-type resin. It is preferable that:

The forming material is prepared as a solution in which the polyvinyl alcohol resin is dissolved in a solvent. Examples of the solvent include water, dimethyl sulfoxide, dimethylformamide, dimethylacetamide N-methylpyrrolidone, various glycols, polyhydric alcohols such as alcohols, and amines such as ethylenediamine and diethylenetriamine. These may be used alone or in combination of two or more. Among these, it is preferable to use it as an aqueous solution using water as a solvent. The concentration of the polyvinyl alcohol-based resin in the forming material (for example, an aqueous solution) is not particularly limited, but is 0.1 to 15% by weight, preferably 0.5%, in consideration of coating properties and storage stability. ~ 10% by weight.

In addition, as for the said forming material (for example, aqueous solution), a plasticizer, surfactant, etc. are mentioned as an additive, for example. Examples of the plasticizer include polyhydric alcohols such as ethylene glycol and glycerin. Examples of the surfactant include nonionic surfactants. Furthermore, coupling agents such as silane coupling agents and titanium coupling agents, various tackifiers, ultraviolet absorbers, antioxidants, heat stabilizers, hydrolysis stabilizers, and other stabilizers can be added.

The transparent resin layer can be formed by applying and drying the forming material on the other surface of the polarizer (the surface on which the protective film is not laminated). The application operation is not particularly limited, and any appropriate method can be adopted. For example, various means such as a roll coating method, a spin coating method, a wire bar coating method, a dip coating method, a die coating method, a curtain coating method, a spray coating method, a knife coating method (comma coating method, etc.) can be employed.

The transparent resin layer is preferably formed of an ultraviolet curable acrylic resin, an ultraviolet curable epoxy resin, a urethane resin, or a polyvinyl alcohol resin. The urethane-based resin layer is formed from the isocyanate-based forming material.

<Adhesive layer>
An appropriate pressure-sensitive adhesive can be used for forming the pressure-sensitive adhesive layer, and the type thereof is not particularly limited. Adhesives include rubber adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, vinyl alkyl ether adhesives, polyvinyl alcohol adhesives, polyvinyl pyrrolidone adhesives, polyacrylamide adhesives, Examples thereof include cellulose-based pressure-sensitive adhesives.

Among these pressure-sensitive adhesives, those having excellent optical transparency, suitable wettability, cohesiveness, and adhesive pressure characteristics, and excellent weather resistance and heat resistance are preferably used. An acrylic pressure-sensitive adhesive is preferably used as one exhibiting such characteristics.

As a method for forming the pressure-sensitive adhesive layer, for example, after the pressure-sensitive adhesive is applied to a release-treated separator and the like, the polymerization solvent is dried and removed to form the pressure-sensitive adhesive layer, and then in the embodiment of FIG. A method of transferring to a polarizer (or a protective film in the embodiment of FIG. 2B), or a polarizer (or a protective film in the embodiment of FIG. 2B) in the embodiment of FIG. It is produced by a method of drying and removing a polymerization solvent and the like to form an adhesive layer on a polarizer. In applying the pressure-sensitive adhesive, one or more solvents other than the polymerization solvent may be added as appropriate.

A silicone release liner is preferably used as the release-treated separator. In the step of forming the pressure-sensitive adhesive layer by applying and drying the pressure-sensitive adhesive of the present invention on such a liner, an appropriate method may be adopted as appropriate according to the purpose. Preferably, a method of heating and drying the coating film is used. The heating and drying temperature is preferably 40 ° C to 200 ° C, more preferably 50 ° C to 180 ° C, and particularly preferably 70 ° C to 170 ° C. By setting the heating temperature within the above range, an adhesive having excellent adhesive properties can be obtained.

Appropriate time can be adopted as the drying time. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

Various methods are used as a method for forming the pressure-sensitive adhesive layer. Specifically, for example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples thereof include an extrusion coating method.

The thickness of the pressure-sensitive adhesive layer is preferably 1 μm or more, and more preferably 5 μm or more from the viewpoint of suppressing peeling. On the other hand, if the thickness of the pressure-sensitive adhesive is too thick, it is preferable that the thickness is 40 μm because nanoslits are likely to be generated due to the bending of the polarizer due to mechanical impact applied after the polarizing film is bonded to the liquid crystal cell. It is 35 μm or less, more preferably 25 μm or less. Moreover, it is preferable that the thickness of an adhesive layer is 35 micrometers or less also from a viewpoint of suppressing the shrinkage | contraction of a polarizer by a thermal shock.

The pressure-sensitive adhesive layer has a storage elastic modulus at 23 ° C. of 1.0 × 10 ⁴ Pa or more, so that the polarizing film with the pressure-sensitive adhesive layer is not subjected to a load due to convex folding on the polarizer side, and is resistant to cracking. This is preferable for ensuring (suppression of nanoslit generation). The storage elastic modulus of the pressure-sensitive adhesive layer is preferably 5.0 × 10 ⁴ Pa or more. On the other hand, when the storage elastic modulus of the pressure-sensitive adhesive layer is increased, the pressure-sensitive adhesive layer tends to be too hard and reworkability is deteriorated. Therefore, the storage elastic modulus of the pressure-sensitive adhesive layer is preferably 1 × 10 ⁸ Pa or less. Further, it is preferably 1 × 10 ⁷ PaPa or less.

When the pressure-sensitive adhesive layer is exposed, the pressure-sensitive adhesive layer may be protected with a peeled sheet (separator) until practical use.

Examples of the constituent material of the separator include, for example, plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and laminates thereof. A thin film can be used, but a plastic film is preferably used because of its excellent surface smoothness.

The plastic film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer. For example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, and a vinyl chloride co-polymer are used. Examples thereof include a polymer film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film.

The thickness of the separator is usually about 5 to 200 μm, preferably about 5 to 100 μm. For the separator, if necessary, mold release and antifouling treatment with a silicone type, fluorine type, long chain alkyl type or fatty acid amide type release agent, silica powder, etc., coating type, kneading type, vapor deposition type It is also possible to carry out antistatic treatment such as. In particular, the release property from the pressure-sensitive adhesive layer can be further improved by appropriately performing a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment on the surface of the separator.

<Surface protection film>
A surface protective film can be provided on the single protective polarizing film and the polarizing film with the pressure-sensitive adhesive layer. The surface protective film usually has a base film and an adhesive layer, and protects the polarizer via the adhesive layer.

As the base film of the surface protective film, a film material having isotropic property or close to isotropic property is selected from the viewpoints of inspection property and manageability. Examples of film materials include polyester resins such as polyethylene terephthalate film, cellulose resins, acetate resins, polyether sulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, acrylic resins, and the like. Examples thereof include transparent polymers such as resins. Of these, polyester resins are preferred. The base film can be used as a laminate of one kind or two or more kinds of film materials, and a stretched product of the film can also be used. The thickness of the base film is generally 500 μm or less, preferably 10 to 200 μm.

The pressure-sensitive adhesive that forms the pressure-sensitive adhesive layer of the surface protective film includes a (meth) acrylic polymer, a silicone-based polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine-based or a rubber-based pressure-sensitive adhesive. Can be appropriately selected and used. From the viewpoints of transparency, weather resistance, heat resistance and the like, an acrylic pressure-sensitive adhesive having an acrylic polymer as a base polymer is preferable. The thickness (dry film thickness) of the pressure-sensitive adhesive layer is determined according to the required adhesive force. Usually, it is about 1 to 100 μm, preferably 5 to 50 μm.

The surface protective film can be provided with a release treatment layer on the surface opposite to the surface on which the pressure-sensitive adhesive layer is provided on the base film, using a low adhesion material such as silicone treatment, long-chain alkyl treatment, or fluorine treatment. .

<Other optical layers>
The piece-protecting polarizing film and the polarizing film with a pressure-sensitive adhesive layer of the present invention can be used as an optical film laminated with another optical layer in practical use. The optical layer is not particularly limited. For example, for forming a liquid crystal display device such as a reflection plate, a semi-transmission plate, a retardation plate (including wavelength plates such as 1/2 and 1/4), and a viewing angle compensation film. One or more optical layers that may be used can be used. In particular, a reflective polarizing film or a semi-transmissive polarizing film in which a reflective plate or a semi-transmissive reflective plate is further laminated on the piece protective polarizing film of the present invention, an elliptical polarizing film in which a retardation plate is further laminated on the polarizing film, or A circular viewing film, a wide viewing angle polarizing film in which a viewing angle compensation film is further laminated on the polarizing film, or a polarizing film in which a brightness enhancement film is further laminated on the polarizing film are preferable.

An optical film obtained by laminating the above optical layer on a single protective polarizing film or a polarizing film with a pressure-sensitive adhesive layer can be formed by a method of sequentially laminating separately in the manufacturing process of a liquid crystal display device, etc. The optical film is excellent in quality stability and assembly work, and has the advantage of improving the manufacturing process of liquid crystal display devices and the like. For the lamination, an appropriate adhesive means such as a pressure-sensitive adhesive layer can be used. When adhering the polarizing film with the pressure-sensitive adhesive layer and other optical films, their optical axes can be arranged at an appropriate angle depending on the intended retardation characteristics and the like.

The piece protective polarizing film, the polarizing film with an adhesive layer or the optical film of the present invention can be preferably used for forming various image display devices such as a liquid crystal display device and an organic EL display device. The liquid crystal display device can be formed according to the conventional method. That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell, a polarizing film with an adhesive layer or an optical film, and an illumination system as necessary, and incorporating a drive circuit. In the invention, there is no particular limitation except that a piece-protecting polarizing film, a polarizing film with a pressure-sensitive adhesive layer or an optical film according to the present invention is used. As the liquid crystal cell, an arbitrary type such as an IPS type or a VA type can be used, but is particularly suitable for the IPS type.

Appropriate liquid crystal display devices such as a liquid crystal display device in which a single protective polarizing film, a polarizing film with an adhesive layer or an optical film are arranged on one or both sides of a liquid crystal cell, or a backlight or reflector used in an illumination system are formed. can do. In that case, the polarizing film with a pressure-sensitive adhesive layer or the optical film according to the present invention can be installed on one side or both sides of the liquid crystal cell. When providing a single protective polarizing film, a polarizing film with an adhesive layer, or an optical film on both sides, they may be the same or different. Further, when forming a liquid crystal display device, for example, a single layer or a suitable part such as a diffusing plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusing plate, a backlight, etc. Two or more layers can be arranged.

<Continuous Manufacturing Method for Image Display Device>
The above image display device is an image of the polarizing film with the pressure-sensitive adhesive layer fed out from the wound body (roll) of the polarizing film with the pressure-sensitive adhesive layer of the present invention and conveyed by the separator through the pressure-sensitive adhesive layer. It is preferably manufactured by a continuous manufacturing method (roll-to-panel method) including a step of continuously bonding to the surface of the display panel. Since the polarizing film with a pressure-sensitive adhesive layer of the present invention is a very thin film, it is cut into a sheet (sheet-fed) and then bonded to the image display panel one by one (“sheet-to-panel method”) According to the above), it is difficult to handle the sheet when it is transported or bonded to the display panel, and the polarizing film (sheet) with the adhesive layer is subjected to a large mechanical impact (for example, bending due to adsorption) in these processes. Risk increases. In order to reduce such a risk, it is necessary to take another measure such as using a thick surface protective film having a thickness of 50 μm or more. On the other hand, according to the roll-to-panel method, the polarizing film with the pressure-sensitive adhesive layer is stably conveyed from the roll to the image display panel by the continuous separator without being cut into a sheet (sheet cutting), Since it is directly bonded to the image display panel, the risk can be greatly reduced without using a thick surface protective film. As a result, coupled with the ability to mitigate mechanical impacts with the transparent resin layer, it is possible to continuously produce an image display panel in which the generation of nanoslits is effectively suppressed.

FIG. 8 is a schematic diagram showing an example of a continuous manufacturing system of a liquid crystal display device adopting a roll-to-panel method.
As shown in FIG. 8, the continuous manufacturing system 100 of the liquid crystal display device includes a series of transport units X that transport the liquid crystal display panel P, a first polarizing film supply unit 101a, a first bonding unit 201a, and a second polarizing film supply. Part 101b and 2nd pasting part 201b are included.
In addition, the wound body (first roll) 20a of the polarizing film with the first pressure-sensitive adhesive layer and the wound body (second roll) 20b of the polarizing film with the second pressure-sensitive adhesive layer have an absorption axis in the longitudinal direction. And the thing of the aspect as described in FIG. 2 (A) is used.

(Transport section)
The transport unit X transports the liquid crystal display panel P. The conveyance unit X is configured to include a plurality of conveyance rollers, a suction plate, and the like. The transport unit X is an arrangement in which the placement relationship between the long side and the short side of the liquid crystal display panel P is switched between the first bonding unit 201a and the second bonding unit 201b with respect to the transport direction of the liquid crystal display panel P. A replacement unit (for example, the liquid crystal display panel P is rotated 90 ° horizontally) 300 is included. Thereby, with respect to the liquid crystal display panel P, the polarizing film 21a with the 1st adhesive layer and the polarizing film 21b with the 2nd adhesive layer can be bonded together in the crossed Nicols relationship.

(First polarizing film supply unit)
The first polarizing film supply unit 101a continuously feeds the first adhesive layer-attached polarizing film (with a surface protective film) 21a fed from the first roll 20a and conveyed by the separator 5a to the first bonding unit 201a. To do. The first polarizing film supply unit 101a includes a first feeding unit 151a, a first cutting unit 152a, a first peeling unit 153a, a first winding unit 154a, and a plurality of conveying roller units, an accumulating unit such as a dancer roll, and the like. Have.

The first feeding portion 151a has a feeding shaft on which the first roll 20a is installed, and feeds the strip-shaped pressure-sensitive adhesive layer-attached polarizing film 21a provided with the separator 5a from the first roll 20a.

The first cutting unit 152a has cutting means and suction means such as a cutter and a laser device. The 1st cutting part 152a cut | disconnects the strip | belt-shaped 1st adhesive film with adhesive layer 21a in the width direction by predetermined length, leaving the separator 5a. However, as the first roll 20a, a strip-like pressure-sensitive adhesive layer-attached polarizing film 21a in which a plurality of score lines are formed in the width direction with a predetermined length is laminated on the separator 5a (an optical film roll with a notch). ) Is not required (the same applies to the second cutting portion 152b described later).

The 1st peeling part 153a peels the polarizing film 21a with a 1st adhesive layer from the separator 5a by folding up with the separator 5a inside. Examples of the first peeling portion 153a include a wedge-shaped member and a roller.

The first winding unit 154a winds up the separator 5a from which the first pressure-sensitive adhesive layer-attached polarizing film 21a has been peeled off. The first winding unit 154a has a winding shaft on which a roll for winding the separator 5a is installed.

(1st bonding part)
The 1st bonding part 201a is the liquid crystal display panel P conveyed by the conveyance part X, the polarizing film 21a with the 1st adhesive layer which peeled the polarizing film 21a with the 1st adhesive layer peeled by the 1st peeling part 153a. Are continuously bonded through the pressure-sensitive adhesive layer (first bonding step). The 1st bonding part 81 has a pair of bonding rollers, and at least one of the bonding rollers is configured by a drive roller.

(Second polarizing film supply unit)
The 2nd polarizing film supply part 101b is continuously supplied to the 2nd bonding part 201b by the 2nd bonding part 201b with the 2nd adhesive film layered polarizing film (with surface protection film) 21b which was drawn | fed out from the 2nd roll 20b, and was conveyed by the separator 5b. To do. The second polarizing film supply unit 101b includes a second feeding unit 151b, a second cutting unit 152b, a second peeling unit 153b, a second winding unit 154b, and a plurality of conveying roller units, an accumulating unit such as a dancer roll, and the like. Have. The second feeding portion 151b, the second cutting portion 152b, the second peeling portion 153b, and the second winding portion 154b are respectively the first feeding portion 151a, the first cutting portion 152a, the first peeling portion 153a, and the first winding. It has the same configuration and function as the taking part 154a.

(2nd bonding part)
The 2nd bonding part 201b is the liquid crystal display panel P conveyed by the conveyance part X. The 2nd adhesive layer-attached polarizing film 21b peeled off by the 2nd peeling part 153b, the 2nd adhesive layer-attached polarizing film 21b Are continuously bonded through the pressure-sensitive adhesive layer (second bonding step). The 2nd bonding part 201b has a pair of bonding rollers, and at least one of the bonding rollers is comprised with a drive roller.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to the examples shown below. In addition, all the parts and% in each example are based on weight. The room temperature standing conditions not specifically defined below are all 23 ° C. and 65% RH.

<Production of polarizer>
(Preparation of polarizer A0)
One side of an amorphous isophthalic acid copolymerized polyethylene terephthalate (IPA copolymerized PET) film (thickness: 100 μm) having a water absorption of 0.75% and Tg of 75 ° C. is subjected to corona treatment. Alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (polymerization degree 1200, acetoacetyl modification degree 4.6%, saponification degree 99.0 mol% or more, manufactured by Nippon Synthetic Chemical Industry Co., Ltd. An aqueous solution containing 9: 1 ratio of the trade name “Gosefimer Z200”) was applied and dried at 25 ° C. to form a PVA-based resin layer having a thickness of 11 μm, thereby preparing a laminate.
The obtained laminate was uniaxially stretched in the longitudinal direction (longitudinal direction) 2.0 times between rolls having different peripheral speeds in an oven at 120 ° C. (air-assisted stretching process).
Next, the laminate was immersed in an insolubilization bath (a boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with respect to 100 parts by weight of water) for 30 seconds (insolubilization treatment).
Subsequently, it was immersed in a dyeing bath having a liquid temperature of 30 ° C. while adjusting the iodine concentration and the immersion time so that the polarizing plate had a predetermined transmittance. In this example, 0.2 parts by weight of iodine was blended with 100 parts by weight of water, and immersed in an aqueous iodine solution obtained by blending 1.0 part by weight of potassium iodide (dyeing treatment). .
Subsequently, it was immersed for 30 seconds in a crosslinking bath having a liquid temperature of 30 ° C. (a boric acid aqueous solution obtained by blending 3 parts by weight of potassium iodide and 3 parts by weight of boric acid with respect to 100 parts by weight of water). (Crosslinking treatment).
Thereafter, the laminate was immersed in a boric acid aqueous solution (an aqueous solution obtained by blending 4 parts by weight of boric acid and 5 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 70 ° C. However, uniaxial stretching was performed between rolls having different peripheral speeds in the longitudinal direction (longitudinal direction) so that the total stretching ratio was 5.5 times (in-water stretching treatment).
Thereafter, the laminate was immersed in a cleaning bath (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 30 ° C. (cleaning treatment).
As a result, an optical film laminate including a polarizer having a thickness of 5 μm was obtained.

(Production of polarizers A0 to A3)
Polarizers A1 to A3 were produced in the same manner as the production of the polarizer A0 except that the production conditions for the polarizer A0 were changed as shown in Table 1. Table 1 shows the thickness, optical characteristics (single transmittance, polarization degree), and boric acid concentration of the polarizers A1 to A3.

(Preparation of polarizer B (12 μm thick polarizer))
A polyvinyl alcohol film having an average polymerization degree of 2400 and a saponification degree of 99.9 mol% and a thickness of 30 μm was immersed in warm water at 30 ° C. for 60 seconds to swell. Next, the film was dyed while being immersed in an aqueous solution of 0.3% concentration of iodine / potassium iodide (weight ratio = 0.5 / 8) and stretched to 3.5 times. Then, it extended | stretched so that the total draw ratio might be 6 time in 65 degreeC borate ester aqueous solution. After stretching, drying was performed in an oven at 40 ° C. for 3 minutes to obtain a PVA polarizer. The thickness of the obtained polarizer was 12 μm.

(Preparation of polarizer C)
One side of an amorphous isophthalic acid copolymerized polyethylene terephthalate (IPA copolymerized PET) film (thickness: 130 μm) having a water absorption of 0.75% and Tg of 75 ° C. is subjected to corona treatment. Alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (polymerization degree 1200, acetoacetyl modification degree 4.6%, saponification degree 99.0 mol% or more, manufactured by Nippon Synthetic Chemical Industry Co., Ltd. An aqueous solution containing 9: 1 ratio of the trade name “Gosefimer Z200”) was applied and dried at 25 ° C. to form a PVA-based resin layer having a thickness of 11 μm, thereby preparing a laminate.
The obtained laminate was contracted 30% in the first direction (MD) at 110 ° C. using a simultaneous biaxial stretching machine, and at the same time, it was stretched in the air in the second direction (TD) by a factor of 5.0. (Stretching treatment).
Next, the laminate was immersed for 40 seconds in an iodine aqueous solution (iodine concentration: 0.2 wt%, potassium iodide concentration: 1.4 wt%) at 25 ° C. (dyeing treatment).
The layered product after dyeing was immersed in a 60 ° C. boric acid aqueous solution (boric acid concentration: 5% by weight, potassium iodide concentration: 5% by weight) for 80 seconds (crosslinking treatment).
After the crosslinking treatment, the laminate was immersed in a 25 ° C. aqueous potassium iodide solution (potassium iodide concentration: 5% by weight) for 20 seconds (cleaning treatment).
As a result, an optical film laminate including a polarizer having a thickness of 3 μm was obtained.

<Protective film>
Acrylic film 1: A (meth) acrylic resin film having a lactone ring structure with a thickness of 40 μm was subjected to corona treatment on the easy adhesion treated surface.

Acrylic film 2: A (meth) acrylic resin film having a lactone ring structure with a thickness of 60 μm was subjected to corona treatment on the easy adhesion treated surface.

Acrylic film 3: A (meth) acrylic resin film having a lactone ring structure with a thickness of 20 μm was subjected to corona treatment on the easy adhesion treated surface.

TAC1: A triacetyl cellulose film having a thickness of 60 μm was used.

TAC 2: A triacetyl cellulose film having a thickness of 40 μm was used.

<Preparation of adhesive applied to protective film>
(Acrylic adhesive 1)
The composition of the transparent resin layer is the same as that of the acrylic forming material (acrylic 1).

(Acrylic adhesive 2)
N-hydroxyethylacrylamide (trade name “HEAA” manufactured by Kojin Co., Ltd.) 12.5 parts acryloylmorpholine (trade name “ACMO (registered trademark)” manufactured by Kojin Co., Ltd.) 25 parts dimethylol-tricyclodecane diacrylate (Kyoeisha) 62.5 parts photoradical polymerization initiator (2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, manufactured by BASF Corp., trade name “Light Acrylate DCP-A”) , Trade name "IRGACURE907") 2 parts Photosensitizer (Diethylthioxanthone, Nippon Kayaku Co., Ltd., trade name "KAYACURE DETX-S") 2 parts

(Acrylic adhesive 3)
N-hydroxyethylacrylamide (trade name “HEAA” manufactured by Kojin Co., Ltd.) 12.5 parts 2-hydroxy-3-phenoxypropyl acrylate (trade name “Aronix® M-5700” manufactured by Toagosei Co., Ltd.) 25 parts 1,9-nonanediol diacrylate (Kyoeisha Chemical Co., Ltd., trade name “Light Acrylate 1.9ND-A”) 40 parts dimethylol-tricyclodecane diacrylate (Kyoeisha Chemical Co., Ltd., trade name “Light Acrylate DCP-A”) 22.5 parts Photoradical polymerization initiator (2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, manufactured by BASF, trade name “IRGACURE907”) 3 parts Photosensitizer (Diethylthioxanthone, manufactured by Nippon Kayaku Co., Ltd., trade name “KAYACURE DETX-S”) 2 parts

(Epoxy adhesive 3)
It is the same as the composition (epoxy 1) of the epoxy-based forming material of the transparent resin layer forming material.

(PVA adhesive)
Polyvinyl alcohol-based resin containing acetoacetyl group (average polymerization degree: 1200, saponification degree: 98.5 mol%, acetoacetylation degree: 5 mol%) to 100 parts, Under temperature conditions, an aqueous solution dissolved in pure water and adjusted to a solid content concentration of 3.7% was prepared. A PVA adhesive was prepared by adding 18 parts of an aqueous colloidal alumina solution (average particle size 15 nm, solid content concentration 10%, positive charge) to 100 parts of the aqueous solution.

<Forming material for transparent resin layer>
(Polyvinyl alcohol-based forming material: PVA1)
A polyvinyl alcohol resin having a polymerization degree of 2500 and a saponification degree of 99.7 mol% was dissolved in pure water to prepare an aqueous solution having a solid content concentration of 4% by weight.

(Composition of acrylic forming material: acrylic 1)
N-hydroxyethylacrylamide (trade name “HEAA” manufactured by Kojin Co., Ltd.) 20 parts Urethane acrylate (trade name “UV-1700B” manufactured by Nippon Synthetic Chemical Co., Ltd.) 80 parts Photoradical polymerization initiator (2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, manufactured by BASF, trade name “IRGACURE907”) 3 parts Photosensitizer (diethylthioxanthone, manufactured by Nippon Kayaku Co., Ltd., trade name “KAYACURE DETX-S” ]) 2 parts

(Epoxy-based material composition: Epoxy 1)
3 ′, 4′-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Daicel Chemical Industries, trade name “Celoxide 2021P”) 100 parts Photocationic polymerization initiator (4- (phenylthio) phenyldiphenylsulfonium hexafluorophosphate , Made by Sun Apro, trade name "CPI-100P")

(Preparation of active energy ray-curable forming material)
Among the adhesive and transparent resin forming material, acrylic and epoxy materials were mixed and stirred at 50 ° C. for 1 hour to prepare various active energy ray curable forming materials.

<Formation of adhesive layer>
(Acrylic adhesive 1)
≪Preparation of acrylic polymer≫
A monomer mixture containing 99 parts of butyl acrylate and 1 part of 4-hydroxybutyl acrylate was charged into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser. Furthermore, 0.1 part of 2,2′-azobisisobutyronitrile as a polymerization initiator was charged with ethyl acetate to 100 parts of the monomer mixture (solid content), and nitrogen gas was introduced while gently stirring. Then, the temperature of the liquid in the flask was kept at around 60 ° C., and a polymerization reaction was carried out for 7 hours. Then, ethyl acetate was added to the resulting reaction solution to prepare a solution of an acrylic polymer having a weight average molecular weight of 1,400,000 adjusted to a solid content concentration of 30%.

<< Preparation of adhesive composition >>
0.2 parts of ethylmethylpyrrolidinium-bis (trifluoromethanesulfonyl) imide (manufactured by Tokyo Chemical Industry) and lithium bis (trifluoromethanesulfonyl) imide (Mitsubishi Materials Electronics) with respect to 100 parts of the solid content of the acrylic polymer solution 1 part), 0.1 part trimethylolpropane xylylene diisocyanate (Mitsui Chemicals: Takenate D110N), 0.3 part dibenzoyl peroxide, and γ-glycidoxypropylmethoxy An acrylic pressure-sensitive adhesive solution was prepared by blending 0.075 part of silane (manufactured by Shin-Etsu Chemical Co., Ltd .: KBM-403).

(Acrylic adhesive 2)
In the preparation of the acrylic polymer of the above acrylic pressure-sensitive adhesive 1, a monomer mixture containing 65 parts of butyl acrylate, 34 parts of methyl methacrylate and 1 part of 4-hydroxybutyl acrylate was used instead of ethyl acetate as a solvent. A solution of an acrylic polymer having a weight average molecular weight of 1.1 million was prepared using toluene. Further, in the preparation of the pressure-sensitive adhesive composition, instead of 0.1 part of trimethylolpropane xylylene diisocyanate (Mitsui Chemicals Co., Ltd .: Takenate D110N), a cross-linking agent containing a compound having an isocyanate group as a main component (Nippon Polyurethane Co., Ltd.) An acrylic pressure-sensitive adhesive solution was prepared in the same manner as the acrylic pressure-sensitive adhesive 1 except that 1 part of manufactured product name “Coronate L”) was used.

(Acrylic adhesive 3)
In the preparation of the acrylic polymer of the acrylic pressure-sensitive adhesive 1, a monomer mixture containing 95 parts of butyl acrylate, 4 parts of acrylic acid and 1 part of 4-hydroxybutyl acrylate was used instead of ethyl acetate as a solvent. A solution of an acrylic polymer having a weight average molecular weight of 2.2 million was prepared using toluene. Further, in the preparation of the pressure-sensitive adhesive composition, instead of 0.1 part of trimethylolpropane xylylene diisocyanate (Mitsui Chemicals Co., Ltd .: Takenate D110N), a cross-linking agent containing a compound having an isocyanate group as a main component (Nippon Polyurethane Co., Ltd.) An acrylic pressure-sensitive adhesive solution was prepared in the same manner as the acrylic pressure-sensitive adhesive 1 except that 0.6 part of the product, trade name “Coronate L”) was used.

Examples 1 to 28, Comparative Examples 1 to 5
(Production of single-protective polarizing film)
A piece protective polarizing film was prepared using the polarizer, adhesive, and protective film shown in Table 1. Table 2 shows the optical properties (single transmittance, degree of polarization) of the obtained piece-protecting polarizing film. In Example 9, two protective films were used, but the adhesive layers shown in Table 1 were also used for the lamination of the two protective films.

In the above, when the polarizers A0 to A3 and C were used, a protective film was bonded to the surface of the polarizer of the optical film laminate through an adhesive layer having a thickness shown in Table 1. Subsequently, the amorphous PET base material was peeled off to produce a piece protective polarizing film using a thin polarizer. In the case of using the polarizer B, a protective film was bonded to one side of the PVA polarizer through a thickness adhesive layer shown in Table 1.

In the above, when the adhesive is acrylic adhesives 1 to 3 and epoxy adhesive 1 (in the case of an ultraviolet curable adhesive), the adhesive is shown in Table 1 with the thickness of the adhesive layer after curing. As described above, the protective film was laminated while being applied to the surface of the polarizer, and then the adhesive was cured by irradiating ultraviolet rays as active energy rays. Ultraviolet irradiation is performed using a gallium-encapsulated metal halide lamp, an irradiation device: Fusion UV Systems, Inc. Light HAMMER 10, Inc., bulb: V bulb, peak illuminance: 1600 mW / cm ² , integrated irradiation amount 1000 / mJ / cm ² (wavelength 380 to 440 nm) ), And the illuminance of ultraviolet rays was measured using a Sola-Check system manufactured by Solatell. When the adhesive is a PVA-based adhesive, the protective film is bonded to the surface of the polarizer so that the adhesive has the thickness of the adhesive layer after drying shown in Table 1. After that, it was dried at 60 ° C. for 1 minute.

<Manufacturing a single protective polarizing film with a transparent resin layer>
Using the transparent resin layer forming material shown in Table 2 so that the thickness shown in Table 2 is formed on the surface of the polarizer of the piece protective polarizing film (the polarizer surface on which the transparent protective film is not provided), A piece protective polarizing film with a transparent resin layer was produced.

In the above, when using the acrylic 1 or epoxy 1 forming material as the transparent resin layer forming material, it is applied to the surface of the polarizer using a wire bar coater and then irradiated with active energy rays in a nitrogen atmosphere. As a result, a transparent resin layer was formed. In addition, irradiation of the active energy ray was performed in the same manner as that used in the production of the piece protective polarizing film.

Moreover, when using PVA1 as a forming material of a transparent resin layer in the above, after apply | coating the said forming material adjusted to 25 degreeC with the wire bar so that the thickness after drying may become the description of Table 2, it is 60 degreeC. And dried with hot air for 1 minute to produce a piece protective polarizing film with a transparent resin layer.

<Preparation of polarizing film with adhesive layer>
On the surface of the polyethylene terephthalate film (separator film) treated with the silicone release agent so that the thickness of the acrylic adhesives 1 to 3 is 5 μm, 15 μm, 20 μm, or 40 μm after drying. The coating was uniformly applied with a fountain coater and dried for 2 minutes in an air circulation type thermostatic oven at 155 ° C. to form an adhesive layer on the surface of the separator film.

Next, the adhesive layer formed on the release treatment surface of the release sheet (separator) was bonded to the transparent resin layer formed on the piece protective polarizing film so as to have the types and thicknesses shown in Table 2, A polarizing film with an adhesive layer was prepared.

The following evaluation was performed on the polarizing film with the pressure-sensitive adhesive layer obtained in the above Examples and Comparative Examples. The results are shown in Table 2.

<Single transmittance T and polarization degree P of polarizer>
The single transmittance T and polarization degree P of the obtained piece-protecting polarizing film were measured using a spectral transmittance measuring device with an integrating sphere (Dot-3c, Murakami Color Research Laboratory).
The degree of polarization P is the transmittance when two identical polarizing films are overlapped so that their transmission axes are parallel (parallel transmittance: Tp), and overlapped so that their transmission axes are orthogonal to each other. It is calculated | required by applying the transmittance | permeability (orthogonal transmittance | permeability: Tc) at the time of combining to the following formula | equation. Polarization degree P (%) = {(Tp−Tc) / (Tp + Tc)} ^1/2 × 100
Each transmittance is represented by a Y value obtained by correcting visibility with a two-degree field of view (C light source) of JIS Z8701, with 100% of the completely polarized light obtained through the Granteller prism polarizer.

<Measurement of boric acid content in polarizer>
Using the Fourier transform infrared spectrophotometer (FTIR) (manufactured by Perkin Elmer, trade name “SPECTRUM2000”), the total reflection attenuation spectroscopy using the polarized light as the measurement light for the polarizers obtained in the examples and comparative examples ( The intensity of the boric acid peak (665 cm ⁻¹ ) and the intensity of the reference peak (2941 cm ⁻¹ ) were measured by ATR) measurement. The boric acid content index was calculated from the obtained boric acid peak intensity and the reference peak intensity by the following formula, and the boric acid content (% by weight) was determined from the calculated boric acid index by the following formula.
(Boric acid amount index) = (Intensity of boric acid peak 665 cm ⁻¹ ) / (Intensity of reference peak 2941 cm ⁻¹ )
(Boric acid content (% by weight)) = (Boric acid content index) × 5.54 + 4.1

<Measurement of compression modulus at 80 ° C.>
TI900 TriboIndenter (manufactured by Hystron) was used for the measurement of the compression modulus. The obtained piece-protecting polarizing film 11 with a transparent resin layer was cut into a size of 10 mm × 10 mm, fixed to a support with a TriboIndenter, and the compression modulus was measured by a nanoindentation method. At that time, the position was adjusted such that the working indenter pushed in the vicinity of the center of the transparent resin layer. The measurement conditions are shown below.
Working indenter: Berkovich (triangular pyramid type)
Measuring method: Single indentation measurement Measuring temperature: 80 ° C
Indentation depth setting: 100 nm

<Measurement of storage modulus>
The storage elastic modulus at 23 ° C. was measured using a viscoelastic spectrometer (trade name: RSA-II) manufactured by Rheometric. The measurement conditions were a measurement value at 23 ° C. in the range of −50 ° C. to 200 ° C. at a frequency of 1 Hz, a sample thickness of 2 mm, a pressure bonding load of 100 g, and a temperature increase rate of 5 ° C./min.

<Inhibition of nano slit generation: Guitar pick test>
Sample 11 was obtained by cutting the obtained polarizing film with an adhesive layer into a size of 50 mm × 150 mm (absorption axis direction was 50 mm). The sample 11 used the surface protective film 6 produced by the following method on the transparent protective film 2 side.

(Surface protection film for testing)
A base molding material made of low density polyethylene having a density of 0.924 g / cm ³ and a melt flow rate at 190 ° C. of 2.0 g / 10 min was supplied to a coextrusion inflation molding machine.
At the same time, a pressure-sensitive adhesive molding material comprising a propylene-butene copolymer having a melt flow rate at 230 ° C. of 10.0 g / 10 min and a density of 0.86 g / cm ³ (propylene: butene = 85: 15 by mass ratio). Was supplied to an inflation molding machine having a die temperature of 220 ° C. to perform coextrusion molding.
As a result, a surface protective film consisting of a 33 μm thick base material layer and a 5 μm thick adhesive layer was produced.

Next, as shown in the conceptual diagram of FIG. 5A and the cross-sectional view of FIG. 5B, the release sheet (separator) is peeled from the sample, and the glass plate 20 is interposed through the exposed adhesive layer 4. Pasted on top. Next, a load of 200 g is applied to the central portion of the sample 11 (surface protective film 6 side) by a guitar pick (manufactured by HISTROY, model number “HP2H (HARD)”), and the absorption axis of the polarizer 1 in the sample 11 is applied. The load load of 50 reciprocations was repeated at a distance of 100 mm in the orthogonal direction. The load was applied at one place.
Next, after the sample 11 was left in an environment of 80 ° C. for 1 hour, the presence or absence of light leakage cracks in the sample 11 was confirmed according to the following criteria.
A: No occurrence.
○: 1 to 5 pieces.
Δ: 6 to 20 pieces.
X: 21 or more.

FIG. 6 shows the following index for the confirmation of the light leakage crack (nano slit a) in the guitar pick test of the piece protective polarizing film 10 or the piece protective polarizing film 11 with a transparent resin layer. It is an example of no. In FIG. 6A, no light leakage crack due to the nano slit a is confirmed. The state shown in FIG. 6A corresponds to before the heating of the guitar pick test of the comparative example and after the heating of the rock and roll test of the example (because of the expansion suppressing effect, the nano slit does not leak light). On the other hand, FIG. 6B shows a case where three cracks of light leakage due to the nano slits a are generated in the absorption axis direction of the polarizer by heating. The state as shown in FIG. 6B corresponds to after heating in the guitar pick test of the comparative example. In FIG. 6, the sample in which the nano slits are generated was observed with a differential interference microscope. When the sample was photographed, the sample without nano slits was set to cross Nicole on the lower side (transmission light source side) of the sample where nano slits were generated and observed with transmitted light. .

<Confirmation of penetration crack: heat shock test>
The obtained polarizing film with a pressure-sensitive adhesive layer was cut into 50 mm × 150 mm (absorption axis direction is 50 mm) and 150 mm × 50 mm (absorption axis direction is 150 mm), and crossed Nicols on both sides of 0.5 mm-thick alkali-free glass. A sample was made by laminating in the direction. The sample was subjected to a heat shock of −40 to 85 ° C. for 30 minutes × 300 times in each environment, and then taken out to visually check whether or not there were through cracks (number) in the polarizing film with the adhesive layer. Confirmed. This test was performed five times. Evaluation was performed according to the following for the number of cracks.
A: 0 sheets.
○: 1 sheet.
Δ: Two sheets.
X: 3 or more sheets.

FIG. 7 is an example of a microphotograph of the surface of the polarizing film, which serves as an index for confirming the penetration crack b of the piece protective polarizing film 10 or the piece protective polarizing film 11 with a transparent resin layer. In FIG. 7, the sample in which the through crack was generated was observed with a differential interference microscope.

<Curl amount>
After the separator was peeled from the obtained polarizing film with the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer surface was faced up at 23 ° C., 55% R.D. H. The curl height (mm) after being left for 30 days under the above conditions was measured and evaluated according to the following criteria.
A: 0 to 5 mm.
A: Over 5 mm to 10 mm.
Δ: Over 10 mm to 30 mm.
X: Over 30 mm.

In addition, as in Comparative Examples 4 and 5, the optical characteristics represented by the single transmittance T and the polarization degree P are represented by the following formula: P> − (10 ^0.929T-42.4 −1) × 100 (however, If the condition of T <42.3) or P ≧ 99.9 (however, T ≧ 42.3) is not satisfied, the problem of the present application (occurrence of through cracks and nano slits) did not occur. .

Example 29
Using a long film as a single protective polarizing film, coating a forming material using a micro gravure coater, a long film as the release sheet (separator) and the following surface protective film It is the same as that of Example 1 except having used. This produced the wound body of the piece protection polarizing film with a transparent resin layer (a mode described in Drawing 2 (A)) by which the separator and the surface protection film were laminated on the transparent resin layer side at the transparent resin layer side. In addition, the wound body of the piece protective polarizing film with the transparent resin layer corresponds to the short side and the long side of the 32-inch non-alkali glass by slit processing in which the cutting proceeds by continuous conveyance of the piece protective polarizing film with the transparent resin layer, respectively. The thing of the width to do was prepared as a set.

(Surface protection film for roll-to-panel)
An acrylic adhesive is applied to the surface opposite to the antistatic surface of the polyethylene terephthalate film (trade name: Diafoil T100G38, manufactured by Mitsubishi Plastics, Inc., thickness 38 μm) with an antistatic layer so that the thickness is 15 μm. The surface protection film was obtained.

Next, using a roll-to-panel type continuous production system as shown in FIG. The polarizing film was continuously bonded to both sides of 100 sheets of 0.5 mm thick 32 inch non-alkali glass so as to have a crossed Nicols relationship.

Examples 30, 31
In the same manner as in Example 29, except that a piece-protecting polarizing film with a transparent resin layer was produced in the same manner as in Examples 2 and 3, respectively.

<Confirmation of nanoslit generation: heating test>
100 pieces of non-alkali glass having a transparent protective resin-coated piece-protecting polarizing film bonded on both sides was placed in an oven at 80 ° C. for 24 hours, and then the presence or absence of nanoslits was visually confirmed. In any of Examples 28 to 30, no defect (light loss) due to the nano slit was observed.

DESCRIPTION OF SYMBOLS 1 Polarizer 2 Protective film 3 Transparent resin layer 4

Adhesive layer

5, 5a,

5b Separator

6, 6a, 6b Surface protective film 10 Single protective polarizing film 11 Single protective polarizing film (with transparent resin layer)
12 Polarizing film with pressure-

sensitive adhesive layer

20a, 20b Rolled body of polarizing film with pressure-sensitive adhesive layer (roll)
21a, 21b Polarizing film with adhesive layer (with surface protective film)
DESCRIPTION OF SYMBOLS 100 Image display apparatus continuous manufacturing system 101a, 101b Polarizing

film supply part

151a, 151b

Feeding part

152a,

152b Cutting part

153a, 153b

Peeling part

154a,

154b Winding part

201a, 201b Bonding part 300 Arrangement part P Image display panel X Image display panel transport section

Claims

A single protective polarizing film having a protective film only on one side of the polarizer,
The polarizer contains a polyvinyl alcohol-based resin, and has an optical characteristic represented by a single transmittance T and a polarization degree P of the following formula: P> − (10 0.929T-42.4 −1) × 100 (Where T <42.3), or
P ≧ 99.9 (provided that T ≧ 42.3) is satisfied,
And when the thickness of the polarizer is X (μm) and the thickness of the transparent resin layer is Y (μm),
X ≦ 12,
Y ≦ 15,
A piece protective polarizing film satisfying 0.15 ≦ (Y / X) ≦ 3.
The piece protective polarizing film according to claim 1, wherein the transparent resin layer has a compressive elastic modulus at 80 ° C of 0.1 GPa or more.
3. The piece protective polarizing film according to claim 1 or 2, wherein the transparent resin layer is formed of an ultraviolet curable acrylic resin, an ultraviolet curable epoxy resin, a urethane resin, or a polyvinyl alcohol resin.
The single protective polarizing film according to any one of claims 1 to 3, further comprising an adhesive layer between the polarizer and the protective film.
The piece protective polarizing film according to claim 4, wherein the adhesive layer has a thickness of 0.1 μm to 5 μm.
The piece protective polarizing film according to claim 4 or 5, wherein the adhesive layer has a compression elastic modulus at 80 ° C of 0.1 GPa or more and 10 GPa or less.
The piece according to any one of claims 4 to 6, wherein the adhesive layer is formed of an ultraviolet curable acrylic resin, an ultraviolet curable epoxy resin, a urethane resin, or a polyvinyl alcohol resin. Protective polarizing film.
The single-protective polarizing film according to any one of claims 1 to 7, wherein the protective film is a single sheet and has a thickness of 10 µm to 100 µm.
The protective film is two sheets, the thickness of each protective film is 10 μm or more, and the total thickness of the protective film is 100 μm or less, and there is an adhesive layer or a pressure-sensitive adhesive layer between the protective films. The piece protective polarizing film according to any one of claims 1 to 7, characterized in that:
10. The piece protective polarizing film according to claim 1, wherein the polarizer contains boric acid in an amount of 25% by weight or less based on the total amount of the polarizer.
A polarizing film with a pressure-sensitive adhesive layer, comprising the piece protective polarizing film according to any one of claims 1 to 10 and a pressure-sensitive adhesive layer.
The polarizing film with a pressure-sensitive adhesive layer according to claim 11, wherein the pressure-sensitive adhesive layer is provided on the transparent resin layer of the piece protective polarizing film.
The polarizing film with a pressure-sensitive adhesive layer according to claim 11, wherein the pressure-sensitive adhesive layer is provided on a protective film of the piece protective polarizing film.
The polarizing film with a pressure-sensitive adhesive layer according to any one of claims 11 to 13, wherein the pressure-sensitive adhesive layer has a thickness of 1 to 40 µm.
15. The polarizing film with the pressure-sensitive adhesive layer according to claim 11, wherein the pressure-sensitive adhesive layer has a storage elastic modulus at 23 ° C. of 1.0 × 10 4 Pa or more.
16. The polarizing film with an adhesive layer according to claim 11, wherein a separator is provided on the adhesive layer.
The polarizing film with an adhesive layer according to claim 16, wherein the polarizing film is a wound body.
An image display device comprising the piece protective polarizing film according to any one of claims 1 to 10 or the polarizing film with an adhesive layer according to any one of claims 11 to 15.
The said polarizing film with an adhesive layer which was drawn | fed out from the winding body of the said polarizing film with an adhesive layer of Claim 17, and was conveyed by the said separator is continuously on the surface of an image display panel through the said adhesive layer. A method for continuously manufacturing an image display device, including a step of bonding to a substrate.