TW201840774A - Pressure-sensitive adhesive layer, one-side-protected polarizing film having pressure-sensitive adhesive layer, image display device, and continuous production method therefor - Google Patents

Abstract

The purpose of the present invention is to provide: a pressure-sensitive adhesive layer in which a defect due to a nano-slit can be inhibited, and which has an excellent antistatic function and reworkability; and a one-side-protected polarizing film having a pressure-sensitive adhesive layer which has that pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer according to the present invention contains a (meth)acrylic polymer as a base polymer, wherein the (meth)acrylic polymer contains, as monomer units, an alkyl(meth)acrylate including an alkyl group having 2-12 carbon atoms, and methyl(meth)acrylate. The pressure-sensitive adhesive layer is characterized by satisfying formula (1). Abs(a): The peak absorbance derived from the antisymmetric stretching vibration of the C-O-C bond of methyl(meth)acrylate, in an IR measurement of the pressure-sensitive adhesive layer using a total reflection measurement method. Abs(b): The peak absorbance derived from the antisymmetric stretching vibration of the C-O-C bond of the alkyl(meth)acrylate, in an IR measurement of the pressure-sensitive adhesive layer using the total reflection measurement method. Abs(c): The lowest absorbance within the range of 800-900 cm-1, in an IR measurement of the pressure-sensitive adhesive layer using the total reflection measurement method.

Description

Adhesive layer, single-sided protective polarizing film with adhesive layer, image display device and continuous manufacturing method thereof

The present invention relates to an adhesive layer and a single-sided protective polarizing film having an adhesive layer of the adhesive layer. The single-sided protective polarizing film with the adhesive layer described above can form an image display device such as a liquid crystal display device (LCD) or an organic EL display device by using an optical film formed by laminating the film alone.

BACKGROUND OF THE INVENTION In a liquid crystal display device, it is indispensable to arrange a polarizing film on both sides of a glass substrate for forming a surface of a liquid crystal panel due to an image forming method. The polarizing film is generally used in a case where a polarizing film made of a dichroic material such as a polyvinyl alcohol-based film and a dichroic material such as iodine is bonded to a protective film by a polyvinyl alcohol-based adhesive or the like.

When the polarizing film is attached to a liquid crystal cell or the like, an adhesive is usually used. Further, the adhesive is previously provided on one surface of the polarizing film in the form of an adhesive layer, and has an advantage that the polarizing film can be fixed instantaneously and the polarizing film can be fixed without requiring a drying step. That is, the polarizing film is generally applied by using a single-sided protective polarizing film with an adhesive layer.

Moreover, the polarizing film or the single-sided protective polarizing film with the adhesive layer is provided with a polarizing member under the harsh environment of thermal shock (such as thermal shock test at -30 ° C and 80 ° C or high temperature test at 100 ° C). The change in the contraction stress causes a problem that cracks (penetrating cracks) are easily generated in the entire absorption axis direction of the polarizer. That is, the one-side protective polarizing film with the adhesive layer is not sufficient for the durability of the thermal punching under the aforementioned severe environment. In particular, from the viewpoint of thinning, the one-side protective polarizing film using the adhesive layer of the one-side protective polarizing film provided with only the protective film on one side of the polarizing member is insufficient in durability against the above-described thermal shock. Further, the penetrating crack due to the thermal shock described above easily occurs when the size of the polarizing film is increased.

For example, in order to impart high durability in a high-temperature environment, it is proposed to use a single-sided protection of an adhesive layer using a storage elastic modulus of 0.2 to 10 MPa and a thickness of 2 μm or more and less than 25 μm at 23 ° C. Adhesive layer of a polarizing film (Patent Document 1). Further, in order to impart good durability in a high-temperature environment, there has been proposed a polarizing plate which is provided with a pressure-sensitive adhesive layer on one side of a polarizing member and a transparent resin film on the other surface of the polarizing member. In the polarizing plate, a polarizing plate exhibiting a storage elastic modulus of 0.15 to 1 MPa in a temperature range of 23 to 80 ° C is used as the pressure-sensitive adhesive layer (Patent Document 2). Further, in order to suppress the occurrence of the above-mentioned penetrating crack, it is proposed to use a method in which the contraction force in the direction perpendicular to the absorption axis of the polarizer is controlled to be small and the storage elastic modulus of the adhesive layer at 23 ° C is 0.20 MPa or more. In the adhesive layer of the one-side protective polarizing film with an adhesive layer (Patent Document 3). Further, the polarizing member is also thinned. For example, a thin polarizing member in which the optical characteristics of the single transmittance and the degree of polarization are controlled and the display is highly aligned is proposed (Patent Document 4).

However, even if the patent document 1 satisfies the durability, since the thickness of the polarizer is as large as 25 μm, the penetrating crack of the polarizer due to the contraction stress cannot be prevented. Further, in Patent Documents 1 to 3, it is a problem to improve the durability of the one-side protective polarizing film with an adhesive layer, and therefore, there are many boric acids used for the polarizer. However, it is known that when the boric acid contained in the polarizer exceeds a certain value, the crosslinking of the boric acid is promoted during heating to increase the contraction stress of the polarizer, so that it is not preferable from the viewpoint of suppressing the occurrence of penetrating cracks. In other words, in Patent Documents 1 to 3, although the storage elastic modulus of the pressure-control adhesive layer can be controlled to a certain extent, the penetration crack can be suppressed to some extent, and it is still impossible to sufficiently suppress the occurrence of the penetration crack.

In addition, the polarizer is also thinned. When the polarizing member for the one-side protective polarizing film with the adhesive layer is thinned, the change in the shrinkage stress of the polarizing member is also reduced. Therefore, it is known that the occurrence of the above-described penetrating crack can be suppressed by using a thinned polarizer.

However, it is known that, in view of the single-sided protective polarizing film of the adhesive layer which suppresses the occurrence of the above-mentioned penetrating crack, the optical characteristics are controlled and the polarizing member is thinned as described in Patent Document 4 (for example, the thickness is set in Under the condition of 12 μm or less), when the single-sided protective polarizing film with the adhesive layer is loaded with mechanical impact (including the case where a convex folding load is applied to the polarizer side), a fine local portion is locally generated in the absorption axis direction of the polarizing member. Slit (hereinafter also referred to as a nano slit). It is also known that the generation of the aforementioned nano slits is independent of the size of the polarizing film. It is also known that the aforementioned nano slits do not occur in the case of using a double-sided protective polarizing film having a protective film on both sides of the polarizing member. Further, it is also known that when a penetrating crack is formed on the polarizer, the stress around the penetrating crack is released, so that the penetrating crack does not form adjacently, but the nano slit is formed adjacent to each other. It is also known that the penetrating crack has a ductility extending in the direction of the absorption axis of the polarizing member in which the crack has occurred, and the nano slit does not have the aforementioned ductility. In this way, the single-sided protective polarizing film which suppresses the occurrence of penetrating cracks is a new problem that occurs when the polarizing material is thinned and the optical characteristics are controlled within a predetermined range. A problem derived from the phenomenon that the above-mentioned penetrating cracks are completely different.

In addition, since the aforementioned nano slit is extremely thin, it cannot be measured under a general environment. Therefore, even if a nano slit is produced on the polarizer, it is difficult to confirm the defect by merely protecting the light leakage of the polarizing film with the one side of the adhesive layer. That is, usually, the one-sided protective polarizing film is formed into a long film shape and then detected by an automatic optical inspection, but it is difficult to detect the nano slit as a defect. It is known that the defects caused by the above-mentioned nano slits can be adhered to the glass substrate of the image display panel and the like when the polarizing film is adhered to the glass substrate of the image display panel, and can be placed in a heating environment, because the nano slits are in the width direction. It is detected by extension (such as the presence or absence of light leakage mentioned above).

Therefore, in the case of using a single-sided protective polarizing film with an adhesive layer of a thin polarizing member, it is not only a penetrating crack but also a defect caused by a nano slit. Further, the one-side protective polarizing film with the adhesive layer is thinner than the polarizing film having the double-sided protection of the protective film on both sides, so that the polarizing film is likely to be bent or broken during handling.

In order to suppress the defects caused by the aforementioned nano slits, there has been proposed a technique of providing a transparent layer (coating layer) between a polarizing member and a pressure-sensitive adhesive layer of a single-sided protective polarizing film with an adhesive layer (Patent Document 5) ). By providing the transparent layer, the polarizing film becomes less likely to be bent when external stress is applied to the polarizing film, so that generation of a nano slit can be suppressed.

Further, when the liquid crystal display device is manufactured, when the single-sided protective polarizing film with the adhesive layer is attached to the liquid crystal cell, the release film is peeled off from the adhesive layer of the polarizing film which is protected on one side of the adhesive layer, and is peeled off. The release film generates static electricity. The static electricity thus generated affects the liquid crystal alignment inside the liquid crystal display device, resulting in defects. Further, when the liquid crystal display device is used, display unevenness due to static electricity may occur. The generation of static electricity can be suppressed by, for example, forming an antistatic layer on the outer surface of the polarizing film, but the effect is small and there is a problem that static electricity cannot be prevented from being generated at all. Therefore, in order to suppress the generation of static electricity from the fundamental position, it is required to impart an antistatic function to the adhesive layer. As means for imparting an antistatic function to the adhesive layer, it has been proposed to incorporate an ionic compound, for example, in an adhesive for forming an adhesive layer (Patent Documents 6 to 8). In detail, Patent Document 6 proposes an adhesive composition for an optical film in which an alkali metal salt and/or an organic cation-anion salt is blended. Patent Document 7 proposes an adhesive composition containing a cerium-anion salt and an alkali metal salt as a raw material of an adhesive layer of a polarizing film with an adhesive layer. In Patent Document 8, an adhesive composition containing an alkali metal salt has been proposed as a raw material of an adhesive layer of an adhesive polarizing plate.

CITATION LIST Patent Literature Patent Literature 1: JP-A-2010-44211 Patent Document 2: JP-A-2008-197309 Patent Document 3: JP-A-2013-72951 Patent Document 4: Japanese Patent No. 4751481 Japanese Patent Laid-Open No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei.

SUMMARY OF THE INVENTION Problems to be Solved by the Invention However, when an ionic compound is blended in an adhesive layer of a single-sided protective polarizing film with an adhesive layer, a single-sided protective polarizing film with an adhesive layer is exposed to a humidifying environment. Under the circumstance, there is a problem that the antistatic function of the adhesive layer is lowered and the polarizing member is deteriorated, and so-called fading and a decrease in the degree of polarization are caused.

In addition, when a polarizing film is adhered to one surface to which a pressure-sensitive adhesive layer is adhered, such as a glass substrate on the surface of the liquid crystal panel, if a foreign matter or a bubble is mixed and a bonding failure occurs, it is necessary to peel the polarizing film from the glass substrate or the like. A one-sided protective polarizing film using an adhesive layer of a thin polarizing member is thin, and since the polarizing member is thin and the protective film is provided only on one side of the polarizing member, the overall thickness is relatively thin. Therefore, the one-side protective polarizing film using the adhesive layer of the conventional thin polarizer has a problem that it is easily broken when peeled off from a glass substrate or the like.

SUMMARY OF THE INVENTION An object of the present invention is to provide an adhesive layer capable of suppressing defects caused by a nano slit and having excellent antistatic function and reworkability, and a single-sided protective polarizing film having an adhesive layer of the adhesive layer.

Further, another object of the present invention is to provide an image display device having the single-sided protective polarizing film with the above-mentioned adhesive layer and a continuous manufacturing method thereof.

Means for Solving the Problem As a result of intensive research, the inventors of the present invention have found that the above problems can be solved by the following adhesive layer, and the present invention has been achieved.

That is, the present invention relates to an adhesive layer characterized in that it contains a (meth)acrylic polymer as a base polymer, and the (meth)acrylic polymer contains an alkyl group having a carbon number of 2 to 12 The alkyl (meth)acrylate and methyl (meth)acrylate are used as monomer units, and the aforementioned adhesive layer satisfies the following formula (1): Abs(a): is the peak absorbance of the asymmetric stretching vibration derived from the COC bond of methyl (meth) acrylate in the IR measurement by the total reflection measurement method of the above-mentioned adhesive layer; Abs(b): The above-mentioned adhesive layer is derived from the peak absorbance of the asymmetric stretching vibration of the COC bond of the alkyl (meth)acrylate in the IR measurement by the total reflection measurement method; Abs(c): the aforementioned adhesive layer The lowest absorbance in the range of 800 to 900 cm ^-1 in the IR measurement by the total reflection measurement method.

The present inventors have actively studied the relationship between the material of the adhesive layer provided on the polarizing film and the number of occurrences of the nano slit, the antistatic function, and the reworkability, and found that the adhesion of the above formula (1) was found. The agent layer can effectively suppress the defects caused by the nano slit and has excellent antistatic function and reworkability. In detail, the adhesive layer can be made highly elastic by using methyl (meth) acrylate as a comonomer of a (meth)acrylic polymer which is a material of the adhesive layer. Thereby, the polarizer can be made less likely to generate a nano slit. Further, since the content of the methyl (meth) acrylate is increased, the adhesive layer can be made more elastic, so that the polarizer can be made more difficult to produce a nano slit. However, since methyl (meth) acrylate increases the cohesive force of the (meth)acrylic polymer, the more the methyl (meth) acrylate content, the higher the adhesion of the adhesive layer, and the rework Sexual deterioration. Further, since the content of methyl (meth)acrylate is increased, the effect of the antistatic function is more inhibited by the steric hindrance of the (meth)acrylic polymer, and the antistatic function of the adhesive layer is lowered. As described above, the present inventors believe that the content of methyl (meth) acrylate which is a comonomer of a (meth)acrylic polymer affects the number of nano slits and the antistatic function of the adhesive layer. And heavy work has a huge impact. Further, the present inventors have found that the adhesive layer is in the IR measurement by the total reflection measurement method (Attenuated Total Reflection, ATR method) with respect to the (meth)acrylic acid derived from the alkyl group having 2 to 12 carbon atoms. The peak absorbance of the asymmetric stretching vibration of the COC bond of the base ester, the adhesive layer derived from the asymmetric stretching vibration of the COC bond of methyl (meth) acrylate having a peak absorbance of 0.30 or more and less than 0.48, can effectively inhibit the nanometer. The defects caused by the slits can be combined with excellent antistatic function and heavy workability.

The aforementioned adhesive layer preferably contains an alkali metal salt and preferably contains a heavy duty lifting agent.

Further, the thickness of the adhesive layer is preferably 25 μm or less.

Furthermore, the present invention relates to a single-sided protective polarizing film with an adhesive layer, which has a single-sided protective polarizing film having a protective film on only one side of the polarizing member, and is on the polarizing member side of the single-sided protective polarizing film. The adhesive layer is directly provided with the above-mentioned adhesive layer or via the coating layer.

The thickness of the polarizing member is preferably 12 μm or less.

Further, the polarizer preferably contains a polyvinyl alcohol-based resin, and is preferably configured such that the optical characteristics represented by the monomer transmittance T and the degree of polarization P satisfy the following formula: P>-(10 ^0.929T-42.4 -1) ×100 (only, T<42.3), or P≧99.9 (only, T≧42.3).

Further, it is preferable that the polarizer contains 25% by weight or less of boric acid with respect to the total amount of the polarizer.

A separator may be provided on the adhesive layer of the polarizing film on one side of the adhesive layer. A one-sided protective polarizing film provided with an adhesive layer of a separate member can be used as a wound body.

Further, the present invention relates to an image display device having a single-sided protective polarizing film with the above-mentioned adhesive layer.

Further, the present invention relates to a continuous manufacturing method of an image display apparatus comprising the steps of: releasing the above-mentioned adhesive layer which is released from a wound body of a single-sided protective polarizing film of the above-mentioned adhesive layer and conveyed by the aforementioned separating member The single-sided protective polarizing film is continuously attached to the surface of the image display panel through the adhesive layer.

EFFECTS OF THE INVENTION The single-sided protective polarizing film with an adhesive layer of the present invention has the above-mentioned adhesive layer, so that the occurrence of a nanoslit can be effectively suppressed without providing a coating layer. Further, in the single-sided protective polarizing film with an adhesive layer of the present invention, since the step of providing the coating layer can be omitted, the productivity can be improved as compared with the conventionally provided coating layer. Further, since the one-side protective polarizing film of the adhesive layer of the present invention has an excellent antistatic function, fading is less likely to occur. Further, since the single-sided protective polarizing film with an adhesive layer of the present invention has excellent reworkability, even if a thin polarizer is used, the polarizing film can be peeled off from the glass substrate or the like without breaking.

MODE FOR CARRYING OUT THE INVENTION A single-sided protective polarizing film with an adhesive layer of the present invention will be described below with reference to Fig. 1 . The one-side protective polarizing film 11 of the adhesive layer of the present invention has, for example, a single-sided protective polarizing film 10 and an adhesive layer 4. The adhesive layer 4 is an adhesive layer of the present invention. As shown in FIG. 1, the one-side protective polarizing film 10 has a protective film 2 only on one side of the polarizing member 1. The polarizer 1 and the protective film 2 are laminated through the adhesive layer 3 (other interposer such as an adhesive layer, a primer layer, etc.). Further, although not shown, the one-side protective polarizing film 10 may be provided with an easy-adhesion layer on the protective film 2 or an activation treatment thereof, and the easy-adhesion layer and the adhesive layer may be laminated. Further, although not shown, a plurality of sheets of the protective film 2 may be provided. The plurality of protective films 2 can be laminated through the adhesive layer 3 (other interposer such as an adhesive layer, a primer layer, etc.).

Further, as shown in Fig. 1, the adhesive layer 4 in the one-side protective polarizing film 11 of the adhesive layer of the present invention may be disposed on the side of the polarizing member 1 of the one-side protective polarizing film 10. Further, although not shown in the drawings, a coating layer may be provided between the polarizer 1 and the adhesive layer 4. The coating layer is not particularly limited, and for example, a known transparent layer described in the specification of Japanese Patent No. 6077618 can be applied. Further, the separator 5 may be provided on the adhesive layer 4 of the one-side protective polarizing film 11 of the adhesive layer of the present invention, and the surface protective film 6 may be provided on the opposite side. In the one-side protective polarizing film 11 with the adhesive layer of Fig. 1, both the separator 5 and the surface protective film 6 are shown. The one-side protective polarizing film 11 having at least the adhesive layer of the separating member 5 (and the surface protective film 6) can be used as a wound body, for example, which is advantageous for application from a winding body as will be described later. The one-side protective polarizing film 11 with the adhesive layer conveyed by the separating member 5 is attached to the surface of the image display panel through the adhesive layer 4 (hereinafter also referred to as "roll to panel method"), which represents There is a specification of Japanese Patent No. 4405034). The one-side protective polarizing film with an adhesive layer described in FIG. 1 is suitably used from the viewpoint of suppressing warpage of the display panel after bonding and suppressing occurrence of a nano slit.

2 is a conceptual diagram comparing the nano slit a and the penetrating crack b formed in the polarizer. 2(A) shows the nano slit a generated in the polarizer 1, and FIG. 2(B) shows the penetrating crack b generated in the polarizer 1. The nano slit a is generated by mechanical impact, and the nano slit a locally generated in the absorption axis direction of the polarizing member 1 cannot be confirmed at the time of generation, but can be in a thermal environment (for example, 80 ° C or 60 ° C). , 90% RH) is confirmed by the expansion in the width direction. On the other hand, it is considered that the nano slit a does not have ductility extending in the absorption axis direction of the polarizer. Further, the aforementioned nano slit a is considered to be produced irrespective of the size of the polarizing film. The nano slit a will be generated by itself and will be generated adjacently. On the other hand, the penetrating crack b is generated by thermal flushing (for example, a thermal shock test). The penetrating crack has a ductility extending in the direction of the absorption axis of the polarizer in which the crack has occurred. When the penetrating crack b is generated, the peripheral stress is released, so the penetrating crack does not form adjacently.

<Polarizer> In the present invention, the thickness of the polarizer is preferably 12 μm or less, more preferably 10 μm or less, still more preferably 8 μm or less, and still more preferably 7 μm from the viewpoint of thinning and suppression of occurrence of penetrating cracks. Hereinafter, it is preferably 6 μm or less. On the other hand, the thickness of the polarizer is preferably 1 μm or more. Such a thin polarizer has a small thickness difference, is excellent in visibility, and has little dimensional change, so that it is excellent in durability against thermal punching.

The polarizer is made of a polyvinyl alcohol-based resin. As the polarizing material, a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, or an ethylene-vinyl acetate copolymer-based partially saponified film may be adsorbed by iodine or a dichroic dye. The coloring matter is uniaxially stretched, and a polyene-based alignment film such as a dehydrated material of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride is used. Among these, a polarizing member composed of a polyvinyl alcohol-based film and a dichroic material such as iodine is preferable.

A polarizing member obtained by dyeing a polyvinyl alcohol-based film by iodine and then uniaxially stretching can be produced, for example, by dipping a polyvinyl alcohol into an aqueous solution of iodine to be dyed, and then extending to 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 of potassium iodide or the like. Further, it is also possible to immerse the polyvinyl alcohol-based film in water for washing with water before dyeing. By washing the polyvinyl alcohol-based film with water, the dirt and the anti-caking agent on the surface of the polyvinyl alcohol-based film can be washed, and the polyvinyl alcohol-based film can be swollen to prevent unevenness such as uneven dyeing. The extension may be carried out after dyeing with iodine, or may be dyed while stretching, or may be dyed with iodine after extension. It is also possible to carry out the extension in an aqueous solution of boric acid or potassium iodide or in a water bath.

From the viewpoint of elongation stability or optical durability, the polarizer is preferably one containing boric acid. In addition, the content of boric acid contained in the polarizer is preferably 25% by weight or less, more preferably 20% by weight or less, from the viewpoint of suppressing the occurrence of the penetration crack and the occurrence of the nano slit, and suppressing the expansion. It is preferably 18% by weight or less, more preferably 16% by weight or less. When the content of the boric acid contained in the polarizer exceeds 25% by weight, even if the thickness of the polarizer is made thin (for example, the thickness is 12 μm or less), the shrinkage stress of the polarizer is increased and the penetration crack is likely to occur, which is not preferable. On the other hand, the boric acid content is preferably 10% by weight or more, and more preferably 12% by weight or more based on the total amount of the polarizing member from the viewpoint of the stability of the polarizing member and the optical durability.

Representative examples of the thin polarizer include: Japanese Patent No. 4751486, Japanese Patent No. 4751481, Japanese Patent No. 4815544, Japanese Patent No. 5048120, Japanese Patent No. 5587517, International Publication No. 2014/ A thin polarizer described in the manual of No. 077599, the manual of International Publication No. 2014/077636, or the thin polarizer produced by the manufacturing method described above.

The polarizer is preferably configured such that the optical characteristics represented by the single transmittance T and the degree of polarization P satisfy the following formula: P>-(10 ^0.929T-42.4 -1)×100 (only, T<42.3), Or P≧99.9 (only, T≧42.3). In a nutshell, a polarizer configured to satisfy the aforementioned conditions has performance required for a display for a liquid crystal television using a large display element. Specifically, the contrast ratio is 1000:1 or more and the maximum brightness is 500 cd/m ² or more. For other uses, for example, it can be attached to the viewing side of the organic EL display device.

On the other hand, since the polarizer which satisfies the above-described conditions exhibits a high degree of alignment due to a polymer (for example, a polyvinyl alcohol-based molecule), it is compatible with a thin type (for example, a thickness of 12 μm or less) to absorb the polarizer. The tensile fracture stress in the direction perpendicular to the axial direction is remarkably small. As a result, for example, when subjected to a mechanical impact greater than the tensile crack stress during the manufacture of the polarizing film, the nano slit is likely to be generated along the absorption axis direction of the polarizer. Therefore, the present invention is particularly suitable for use with a one-sided protective polarizing film having the polarizing member (or a single-sided protective polarizing film having an adhesive layer therewith).

In the method of including the step of stretching in the state of the laminated body and the dyeing step, the thin polarizing member is, for example, a specification such as Japanese Patent No. 4751486, Japanese Patent No. 4751481, from the viewpoint of being able to extend at a high magnification and improving the polarizing performance. The method described in the specification of Japanese Patent No. 4815544 is preferably prepared by a method comprising the step of extending in an aqueous solution of boric acid, and is particularly described in the specification of Japanese Patent No. 4751481 and Japanese Patent No. 4815544. It is preferred to prepare a process comprising the step of assisting in the air extension before extending in an aqueous solution of boric acid. The thin polarizing members can be obtained by a method comprising the steps of: extending a layer of a polyvinyl alcohol-based resin (hereinafter also referred to as a PVA-based resin) and a resin substrate for stretching in a state of a laminate; Dyeing step. In this production method, even if the PVA-based resin layer is thin, it can be extended by the resin substrate for extension and can be stretched without causing breakage such as elongation.

<Protective film> The material constituting the protective film is preferably excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, and the like. Examples thereof include polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; cellulose polymers such as diethyl phthalocyanine and triethylene fluorene; and polymethyl methacrylate An acrylic polymer such as an ester; a styrene polymer such as polystyrene or an acrylonitrile-styrene copolymer (AS resin); and a polycarbonate polymer. Further, examples of the polymer which forms the above-mentioned transparent protective film may be exemplified by polyethylene, polypropylene, polyolefin having a ring system or a norbornene structure, and polyolefin polymerization such as an ethylene-propylene copolymer. a phthalamide polymer such as a vinyl chloride polymer, a nylon or an aromatic polyamine, an imine polymer, a fluorene polymer, a polyether fluorene polymer, a polyetheretherketone polymer, and a stretching a benzene sulfide polymer, a vinyl alcohol polymer, a vinyl chloride polymer, a vinyl butyral polymer, an aryl ester polymer, a polyoxymethylene polymer, an epoxy polymer or the above polymer Blends and the like.

Further, the protective film may contain one or more optional and appropriate additives. The additives may, for example, be ultraviolet absorbers, antioxidants, slip agents, plasticizers, mold release agents, anti-colorants, flame retardants, nucleating agents, antistatic agents, pigments, colorants and the like. The content of the above thermoplastic resin in the transparent protective film is preferably from 50 to 100% by weight, preferably from 50 to 99% by weight, more preferably from 60 to 98% by weight, particularly preferably from 70 to 97% by weight. When the content of the thermoplastic resin in the protective film is 50% by weight or less, the original high transparency of the thermoplastic resin or the like may not be sufficiently exhibited.

As the protective film, a retardation film, a brightness enhancement film, a diffusion film, or the like can also be used. The retardation film may have a phase difference of 40 nm or more in the front phase and/or 80 nm or more in the thickness direction. 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. When a retardation film is used as the protective film, the retardation film can also function as a polarizer protective film, so that it can be made thinner.

The retardation film is a birefringent film formed by subjecting a thermoplastic resin film to uniaxial or biaxial stretching treatment. The temperature, the stretching ratio, and the like of the above extension may be appropriately set in accordance with the phase difference value, the film material, and the thickness.

The thickness of the protective film can be appropriately determined, and it is generally about 1 to 500 μm from the viewpoints of workability such as strength and handleability, and thin layer properties. It is particularly preferably 1 to 300 μm, preferably 5 to 200 μm, more preferably 5 to 150 μm, and particularly preferably 5 to 80 μm.

A functional layer such as a hard coat layer, an antireflection layer, an anti-adhesion layer, a diffusion layer, and an anti-glare layer may be disposed on the surface of the protective film that is not adjacent to the polarizing member. Further, the functional layer such as the hard layer, the antireflection layer, the anti-adhesion layer, the diffusion layer, and the anti-glare layer may be provided separately from the protective film in addition to the protective film itself, and may be other individuals.

<Interposer> The protective film and the polarizer may be laminated through an interposer such as an adhesive layer, an adhesive layer, or a primer layer. At this time, it is desirable to laminate the two without an air gap by the interposer. Preferably, the protective film and the polarizing member are laminated through the adhesive.

The layer of the agent is then formed from an adhesive. The kind of the subsequent agent is not particularly limited, and various substances can be used. The adhesive layer is not particularly limited as long as it is optically transparent, and various materials such as water, solvent, hot melt adhesive, and active energy ray-curable can be used as the adhesive, and water-based adhesive or active energy ray-curable type can be used. The subsequent agent is preferably.

The water-based adhesive may, for example, be an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex, or an aqueous polyester. The aqueous adhesive is usually used as an adhesive composed of an aqueous solution, and usually contains 0.5 to 60% by weight of a solid component.

The active energy ray-curable adhesive is an adhesive which is cured by an active energy ray such as an electron beam or an ultraviolet ray (radical hardening type or cation hardening type), and can be used, for example, in an electron beam curing type or an ultraviolet curing type. As the active energy ray-curable adhesive, for example, a photo-radical curing type adhesive can be used. When the photoradical curing type active energy ray-curable adhesive is used in an ultraviolet curing type, the adhesive contains a radical polymerizable compound and a photopolymerization initiator.

The coating method of the subsequent agent can be appropriately selected according to the viscosity of the adhesive or the target thickness. Examples of the coating method include a reverse coater, a gravure coater (direct, reverse or indirect), a bar reverse coater, a roll coater, a die coater, a bar coater, a bar coater, and the like. . In other respects, the coating may be suitably carried out by a dip coating method or the like.

Further, when a water-based adhesive or the like is used for the application of the above-mentioned adhesive, it is preferred to carry out the thickness of the finally formed adhesive layer to be 30 to 300 nm. The thickness of the above adhesive layer is more preferably 60 to 250 nm. Further, when an active energy ray-curable adhesive is used, it is preferred to carry out the thickness of the adhesive layer to be 0.1 to 200 μm. It is preferably 0.5 to 50 μm, more preferably 0.5 to 10 μm.

Further, in the case of laminating the polarizer and the protective film, an easy-adhesion layer may be provided between the protective film and the adhesive layer. The easy-adhesion layer may be formed of various resins having a skeleton such as a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a polyoxynitride system, a polyamine skeleton, and a polyimine skeleton. , polyvinyl alcohol skeleton, and the like. These polymer resins may be used alone or in combination of two or more. Further, other additives may be added when the easy-to-adhere layer is formed. Specifically, a stabilizer such as an adhesive, an ultraviolet absorber, an antioxidant, a heat stabilizer, or the like can be used.

The easy-adhesion layer is usually provided on the protective film in advance, and the easy-adhesion layer side of the protective film is laminated with the polarizer by an adhesive layer. The formation of the easy-adhesion layer can be carried out by applying a forming material of the easily-adhesive layer to the protective film and drying it by a known technique. The formation of the easy-adhesion layer is usually adjusted to a solution diluted to an appropriate concentration in consideration of the thickness after drying, the smoothness of application, and the like. The thickness of the easy-adhesive layer after drying is preferably 0.01 to 5 μm, more preferably 0.02 to 2 μm, and more preferably 0.05 to 1 μm. Further, the easy-adhesion layer may be provided with a plurality of layers, and it is also preferable to make the total thickness of the easy-adhesion layer fall within the above range.

The adhesive layer is formed of an adhesive. As the adhesive, various adhesives can be used, and examples thereof include a rubber-based adhesive, an acrylic adhesive, a polyoxygen-based adhesive, an urethane-based adhesive, a vinyl alkyl ether adhesive, and a polyvinylpyrrole. A ketone-based adhesive, a polypropylene amide-based adhesive, a cellulose-based adhesive, and the like. The adhesive base polymer can be selected in accordance with the type of the aforementioned adhesive. Among the above-mentioned adhesives, it is preferred to use an acrylonitrile-based adhesive in terms of excellent optical transparency, exhibiting appropriate wettability, adhesive properties of cohesiveness and adhesion, and excellent weather resistance and heat resistance.

The undercoat layer (primer layer) is formed in order to improve the adhesion between the polarizer and the protective film. The material constituting the undercoat layer is not particularly limited as long as it can exert a certain strong adhesion to both the base film and the polyvinyl alcohol-based resin layer. For example, a thermoplastic resin excellent in transparency, thermal stability, and elongation can be used. The thermoplastic resin may, for example, be an acrylic resin, a polyolefin resin, a polyester resin, a polyvinyl alcohol resin, or a mixture thereof.

<Adhesive Layer> The adhesive layer of the present invention provided on the one-side protective polarizing film contains a (meth)acrylic polymer as a base polymer. The (meth)acrylic polymer is a (meth)acrylic acid alkyl ester having an alkyl group having 2 to 12 carbon atoms and methyl (meth)acrylate as a monomer unit. Further, the adhesive layer of the present invention is characterized by satisfying the following formula (1). Further, the alkyl group of the alkyl (meth)acrylate may have various substituents. In the case of the above, the carbon number of the alkyl group does not include the carbon number of the substituent. Abs(a): the peak absorbance Abs(b) of the asymmetric stretching vibration derived from the COC bond of methyl (meth) acrylate in the IR measurement by the total reflection measurement method of the above-mentioned adhesive layer: In the IR measurement by the total reflection measurement method, the adhesive layer is derived from the peak absorbance Abs(c) of the asymmetric stretching vibration of the COC bond of the alkyl (meth)acrylate: the adhesive layer is utilized. The lowest absorbance in the range of 800 to 900 cm ^-1 in the IR measurement by the total reflection measurement method

The peak value of the asymmetric stretching vibration of the COC bond derived from methyl (meth) acrylate appears in the range of 1100 to 1130 cm ^-1 . Further, the peak value of the asymmetric stretching vibration derived from the COC bond of the alkyl (meth) acrylate is in the range of 1150 to 1260 cm ^-1 .

Abs(c) is the lowest absorbance in the range of 800-900 cm ^-1 , which is the absorbance at baseline.

If the IR parameter [(Abs(a)-Abs(c))/(Abs(b)-Abs(c))] of the above formula (1) is outside the range of the above-mentioned values, the crack of the adhesive layer is inhibited. Any of the functional, heavy-duty, or antistatic functions deteriorates.

The adhesive layer of the present invention is formed by using an acrylic adhesive. Acrylic adhesives are excellent in optical transparency, exhibit moderate wettability, cohesiveness and adhesion properties, and have excellent weather resistance and heat resistance. Therefore, they are suitable as a material for forming an adhesive layer.

The acrylic adhesive is a monomer unit having a (meth)acrylic acid alkyl ester having a carbon number of 2 to 12 as a main skeleton, and a monomer unit containing methyl (meth) acrylate (A) The acrylic polymer is used as the base polymer. The (meth)acrylic polymer may contain a monomer unit of a (meth) acrylate other than the above, within a range that does not impair the effects of the present invention. Further, (meth) acrylate means acrylate and/or methacrylate, and (meth) of the present invention has the same meaning.

The alkyl group of the alkyl group having 2 to 12 carbon atoms, and specific examples thereof may be ethyl (meth)acrylate, propyl (meth)acrylate or isopropyl (meth)acrylate. , n-butyl (meth)acrylate, isobutyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (methyl) Octyl acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, decyl (meth) acrylate, and dodecyl (meth) acrylate. Further, an alkyl group such as a carboxyalkyl (meth)acrylate, a hydroxyalkyl (meth)acrylate, an amine alkyl (meth)acrylate or an alkoxyalkyl (meth)acrylate may be mentioned. The (meth) acrylate having a number of 2 to 12 substituted alkyl groups. These may be used alone or in combination. Among these, at least one selected from the group consisting of ethyl acrylate, propyl acrylate, n-butyl acrylate, n-amyl methacrylate, n-hexyl acrylate, and 2-ethylhexyl acrylate is preferably used. Use n-butyl acrylate. In addition, when two or more kinds of the (meth)acrylic acid alkyl esters are used, Abs(b) in the above formula (1) is a total value of peak absorbances (however, there is a case where one type of peak appears) .

In order to obtain the adhesive layer satisfying the above formula (1), the (meth)acrylic polymer preferably contains 70 to 99% by weight of the alkyl (meth)acrylate having the carbon number of the alkyl group of 2 to 12 as the alkyl group. The monomer unit preferably contains 75 to 98% by weight, and more preferably contains 80 to 96% by weight. Further, the (meth)acrylic polymer preferably contains 1 to 15% by weight of methyl (meth)acrylate as a monomer unit, more preferably 2 to 12% by weight, and still more preferably 4 to 10% by weight.

In the (meth)acrylic polymer, one or more kinds of monomers can be introduced by copolymerization in order to improve adhesion and thermal conductivity. Specific examples of the comonomer include a carboxyl group-containing monomer, a hydroxyl group-containing monomer, a nitrogen-containing monomer, and an aromatic group-containing monomer.

Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid and the like. These may be used alone or in combination.

The hydroxyl group-containing monomer may, for example, be 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate or 6-hydroxyhexyl (meth)acrylate. Further, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)-methyl acrylate. These may be used alone or in combination.

The nitrogen-containing monomer may, for example, be a vinyl monomer having a lactam ring (for example, a vinyl pyrrolidone monomer such as N-vinylpyrrolidone or methylvinylpyrrolidone; and having a β-inner) a vinyl indoleamine monomer such as a guanamine ring, a δ-indoleamine ring, and an indoleamine ring such as an ε-indoleamine ring; a maleimide, an N-cyclohexylmaleimide, Maleic amine amide monomer such as N-phenylmaleimide; (meth) acrylamide, N,N-dimethyl(meth) acrylamide, N,N-diethyl ( Methyl) acrylamide, N-hexyl (meth) acrylamide, N-methyl (meth) acrylamide, N-butyl (meth) acrylamide, N-butyl (methyl) (N-substituted) guanamine monomer such as acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide or the like; amine ethyl (meth) acrylate , (meth) propyl methacrylate, N,N-dimethylamine ethyl (meth) acrylate, tert-butylamine ethyl (meth) acrylate, 3-(3-pyridyl) propyl ( (meth)acrylic acid aminoalkyl-based monomer such as methyl acrylate; N-(methyl) propylene oxymethylene succinimide, N-(methyl) propylene fluorenyl-6- Aromatic succinimide monomers such as hexamethylene succinimide, N-(methyl) propylene decyl-8-oxy octamethyl succinimide, etc.; cyanide such as acrylonitrile or methacrylonitrile; Base (meth) acrylate monomer; vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl pipe Vinylpyr , vinyl pyrrole, vinyl imidazole, vinyl Oxazole, vinyl orolin, N-vinyl carboxylic acid amides, and the like. These may be used alone or in combination.

The aromatic group-containing monomer may, for example, be benzyl (meth)acrylate, phenyl (meth)acrylate or phenoxyethyl (meth)acrylate. These may be used alone or in combination.

In addition to the above monomers, an acid anhydride group-containing monomer such as maleic anhydride or itaconic anhydride; a caprolactone adduct of acrylic acid; a styrenesulfonic acid or allylsulfonic acid, 2-(A) a sulfonic acid group such as acrylamide-2-methylpropanesulfonic acid, (meth)acrylamide, propanesulfonic acid, sulfopropyl (meth)acrylate or (meth)acryloxynaphthalenesulfonic acid a monomer; a phosphate group-containing monomer such as 2-hydroxyethyl acryloyl phosphate. These may be used alone or in combination.

Further, a vinyl monomer such as vinyl acetate, vinyl propionate, styrene, α-methylstyrene or N-vinyl caprolactam may be used; or a glycidyl (meth)acrylate may be used. Epoxy group-containing acrylic monomer; (meth)acrylic acid polyethylene glycol ester, (meth)acrylic acid polypropylene glycol ester, (meth)acrylic acid methoxyethylene glycol ester, (meth)acrylic acid methoxy group a diol-based acrylate monomer such as polypropylene glycol ester; tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate, poly methoxy (meth) acrylate, 2-methoxyethyl acrylate, etc. An acrylate monomer or the like. These may be used alone or in combination.

From the viewpoint of enhancing the cohesive force of the (meth)acrylic polymer to more effectively suppress the generation of the aforementioned nano slit, it is preferred to be selected from the above-mentioned carboxyl group-containing monomer, the aforementioned hydroxyl group-containing monomer, and the aforementioned nitrogen-containing single sheet. At least one polar monomer in the body is introduced into the (meth)acrylic polymer by copolymerization, and it is more preferred to introduce the carboxyl group-containing monomer, the hydroxyl group-containing monomer and the nitrogen-containing monomer into the above by copolymerization ( In a methyl) acrylic polymer. The above carboxyl group-containing monomer is preferably (meth)acrylic acid. The hydroxyl group-containing monomer is preferably one or more selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. The nitrogen-containing monomer is preferably a vinyl monomer having a lactam ring, more preferably the vinylpyrrolidone monomer, and more preferably N-vinylpyrrolidone. By introducing the aforementioned nitrogen-containing monomer into the (meth)acrylic polymer by copolymerization, the generation of the nano slit can be more effectively suppressed, and at the same time, the durability of the adhesive layer at high temperature and/or high humidity can be improved. (resistance to peeling).

The (meth)acrylic polymer preferably contains 0.01 to 2% by weight of the carboxyl group-containing monomer as a monomer unit, more preferably 0.05 to 1% by weight, still more preferably 0.1 to 0.3% by weight.

The (meth)acrylic polymer preferably contains 0.01 to 1% by weight of the hydroxyl group-containing monomer as a monomer unit, more preferably 0.05 to 1% by weight, still more preferably 0.1 to 0.5% by weight.

The (meth)acrylic polymer preferably contains 0.1 to 5% by weight of the nitrogen-containing monomer as a monomer unit, more preferably 0.5 to 3% by weight, and still more preferably 1.5 to 3% by weight.

The average molecular weight of the (meth)acrylic polymer is not particularly limited, but the weight average molecular weight is preferably from about 500,000 to about 2.5 million. The above-mentioned (meth)acrylic polymer can be produced by various known methods, and a radical polymerization method such as a bulk polymerization method, a solution polymerization method, or a suspension polymerization method can be appropriately selected. As the radical polymerization initiator, various known azo-based or peroxide-based compounds can be used. The reaction temperature is usually about 50 to 80 ° C, and the reaction time is set to 1 to 8 hours. Further, in the above production method, a solution polymerization method is preferred, and a solvent of the (meth)acrylic polymer is generally ethyl acetate, toluene or the like.

A crosslinking agent may be blended in the aforementioned adhesive. By means of the cross-linking agent, the adhesion and durability can be improved, and the reliability at high temperatures can be maintained and the shape of the adhesive itself can be maintained. As the crosslinking agent, an isocyanate type, an epoxy type, a peroxide type, a metal chelate type, or the like can be suitably used. Oxazoline and the like. These crosslinking agents may be used alone or in combination of two or more.

An isocyanate compound can be used for an isocyanate type crosslinking agent. The isocyanate compound may, for example, be tolylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, decyl diisocyanate, diphenylmethane diisocyanate, hydrogenated An isocyanate monomer such as diphenylmethane diisocyanate or an adduct isocyanate compound obtained by adding such an isocyanate monomer to trimethylolpropane or the like; a trimeric isocyanate, a biuret-type compound, and a known A urethane prepolymer type isocyanate obtained by addition reaction of a polyether polyol or a polyester polyol, an acrylic polyol, a polybutadiene polyol, and a polyisoprene polyol.

The isocyanate-based crosslinking agent may be used singly or in combination of two or more kinds, and the total content is preferably 0.01 to 2 parts by weight based on 100 parts by weight of the base polymer, and the isocyanate-based crosslinking agent is contained. It is preferably contained in an amount of 0.02 to 2 parts by weight, more preferably 0.05 to 1.5 parts by weight. It is preferable to contain a crosslinking agent in consideration of cohesive force, peeling at the time of durability test, etc..

Various peroxides can be used as the peroxide crosslinking agent. The peroxide may, for example, be bis(2-ethylhexyl)peroxydicarbonate, bis(4-tert-butylcyclohexyl)peroxydicarbonate, di-secondary butylperoxydicarbonate, or the like. Butyl peroxy neodecanoate, trimethyl hexyl peroxyacetate, trimethyl ethane tributyl sulphate, dilauroyl peroxide, di-n-octyl decyl peroxide, 1,1 ,3,3-tetramethylbutylperoxyisobutyrate, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, bis(4-methylbenzamide) Base) peroxide, benzhydryl peroxide, tertiary butyl peroxyisobutyrate, and the like. Among these, it is particularly preferable to use bis(4-tert-butylcyclohexyl)peroxydicarbonate, dilauroyl peroxide, and benzhydryl peroxide having excellent crosslinking reaction efficiency.

The peroxide may be used singly or in combination of two or more kinds, but the total content is 0.01 to 2 parts by weight, and preferably 0.04 to 1.5, based on 100 parts by weight of the base polymer. The parts by weight are more preferably 0.05 to 1 part by weight. It can be appropriately selected within this range to adjust workability, reworkability, crosslinking stability, peelability, and the like.

Further, the above adhesive may contain a decane coupling agent. Durability can be improved by using a decane coupling agent. As the decane coupling agent, those having any and appropriate functional groups can be used. Specific examples of the functional group include a vinyl group, an epoxy group, an amine group, a mercapto group, a (meth)acryloxy group, an ethyl oxime group, an isocyanate group, a styryl group, a polysulfide group, and the like. Specific examples thereof include vinyl-containing decane coupling agents such as vinyl triethoxy decane, vinyl tripropoxy decane, vinyl triisopropoxy decane, and vinyl tributoxy decane; and γ-rings; Oxypropoxypropyltrimethoxydecane, γ-glycidoxypropyltriethoxydecane, 3-glycidoxypropylmethyldiethoxydecane, 2-(3,4- Epoxy-containing decane coupling agent such as epoxycyclohexyl)ethyltrimethoxydecane; γ-aminopropyltrimethoxydecane, N-β-(aminoethyl)-γ-aminopropylmethyl dimethyl Oxydecane, N-(2-aminoethyl) 3-aminopropylmethyldimethoxydecane, γ-triethoxyindolyl-N-(1,3-dimethylbutylidene)propylamine, An amine group-containing decane coupling agent such as N-phenyl-γ-aminopropyltrimethoxydecane; a decyl-containing decane coupling agent such as γ-mercaptopropylmethyldimethoxydecane; and p-styrenetrimethoxydecane a styrene-based decane coupling agent; a (meth)acrylic group-containing decane coupling agent such as γ-acryloxypropyltrimethoxydecane or γ-methacryloxypropyltriethoxydecane ; 3-isocyanate propyl triethoxy decane, etc. Silane coupling agent of the ester group; bis (silicon based triethoxysilylpropyl) tetrasulfide polysulfide silicon-containing alkyl group of the coupling agent.

The decane coupling agent may be used singly or in combination of two or more kinds, but the total content of the decane coupling agent is preferably 0.001 to 5 parts by weight, preferably 0.01 to 1 part by weight, based on 100 parts by weight of the base polymer. More preferably, it is 0.02 to 1 part by weight, and preferably 0.05 to 0.6 part by weight.

Further, from the viewpoint of improving the reworkability, the aforementioned adhesive agent preferably contains a heavy duty lifting agent. The aforementioned heavy duty lifting agent is a chemical substance which has a polar group and is easy to interact with the glass interface and is easy to segregate the glass interface. The heavy duty lifting agent may, for example, be a diol having an alkoxy group such as EO or PO, an oligomer having a perfluoroalkyl group, or a reactive fluorenyl polyether compound. The polyether compound can be used, for example, as disclosed in Japanese Laid-Open Patent Publication No. 2010-275522.

Examples of the polyether compound having a reactive mercapto group include MS polymers S203, S303, and S810 manufactured by KANEKA Co., Ltd.; SILYL EST250 and EST280; SAT10, SAT200, SAT220, SAT350, SAT400, and EXCESTAR S2410 and S2420 manufactured by Asahi Glass Co., Ltd. or S3430 and so on.

The content of the heavy duty lifting agent is preferably 0.001 parts by weight or more, more preferably 0.01 parts by weight or more, still more preferably 0.1 parts by weight or more, and preferably 10 parts by weight or less, more preferably 5 parts by weight per 100 parts by weight of the base polymer. It is more preferably 2 parts by weight or less, and still more preferably 1 part by weight or less. If the content of the heavy duty lifting agent is less than 0.001 part by weight, it may be difficult to increase the reworkability of the adhesive layer, and if it is more than 10 parts by weight, the adhesive property of the adhesive layer tends to decrease.

Further, the above adhesive preferably contains an antistatic agent. When a liquid crystal display device is manufactured, when a single-sided protective polarizing film with an adhesive layer is attached to a liquid crystal panel, the release film is peeled off from the adhesive layer of the polarizing film on one side of the adhesive layer, and the release film is peeled off. The mold film generates static electricity. Further, when the one-side protective polarizing film with the adhesive layer is bonded to the liquid crystal panel, if the bonding failure occurs, the polarizing film must be peeled off, and static electricity is generated when the polarizing film is peeled off. The generated static electricity affects the liquid crystal alignment inside the liquid crystal display device and causes a defect. Further, when the liquid crystal display device is used, display unevenness due to static electricity may occur. By adding an antistatic agent to the adhesive, the antistatic function of the adhesive layer of the polarizing film on one side of the adhesive layer can be imparted to prevent such adverse conditions.

The antistatic agent is not particularly limited, and examples thereof include an ionic compound such as a ruthenium-anion salt and an alkali metal salt. We believe that if an ionic compound is added, the ionic compound will overflow the surface of the adhesive layer, effectively exhibiting an antistatic function. On the other hand, when the ionic compound is in contact with the polarizer, the optical characteristics such as the degree of polarization may be lowered. It is preferable to use an alkali metal salt from the viewpoint of suppressing the decrease in the aforementioned optical characteristics.

As the alkali metal salt, an organic or inorganic salt of an alkali metal can be used. The alkali metal salt may be used singly or in combination of two or more.

The alkali metal ion constituting the cationic portion of the alkali metal salt may be, for example, lithium, sodium or potassium. Among these alkali metal ions, lithium ions are preferred.

The anion portion of the alkali metal salt may be composed of an organic substance or an inorganic substance. The anion portion constituting the organic salt may, for example, be CH ₃ COO ^- , CF ₃ COO ^- , CH ₃ SO ₃ ^- , CF ₃ SO ₃ ^- , (CF ₃ SO ₂ ) ₂ N ^- , (CF ₃ SO ₂ ) ₃ C ^- , C ₄ F ₉ SO ₃ ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , C ₃ F ₇ COO ^- , (CF ₃ SO ₂ )(CF ₃ CO)N ^- , ^- O ₃ S( CF ₂ ) ₃ SO ₃ ^- , PF ₆ ^- , CO ₃ ^2- and the like. In particular, the anion portion of the fluorine-containing atom is suitable for use because it can obtain an ionic compound excellent in ion dissociation. The anion portion constituting the inorganic salt may be Cl ^- , Br ^- , I ^- , AlCl ₄ ^- , Al ₂ Cl ₇ ^- , BF ₄ ^- , PF ₆ ^- , ClO ₄ ^- , NO ₃ ^- , AsF ₆ ^- , SbF ₆ ^- , NbF ₆ ^- , TaF _6- , (CN) ₂ N ^- and the like. The anion moiety is preferably (CF ₃ SO ₂ ) ₂ N ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- or the like (perfluoroalkylsulfonyl) quinone imine, especially (CF ₃ SO ₂ ) ₂ N ^- shown in (trifluoromethane sulfonic acyl) (PEI) is preferred.

The organic salt of an alkali metal may specifically be exemplified by sodium acetate, sodium alginate, sodium lignosulfonate, sodium toluenesulfonate, LiCF ₃ SO ₃ , Li(CF ₃ SO ₂ ) ₂ N, Li(CF ₃ SO ₂ ) _{2 .} N, Li(C ₂ F ₅ SO ₂ ) ₂ N, Li(C ₄ F ₉ SO ₂ ) ₂ N, Li(CF ₃ SO ₂ ) ₃ C, KO ₃ S(CF ₂ ) ₃ SO ₃ K, LiO ₃ S(CF ₂ ) ₃ SO ₃ K, etc., among which are LiCF ₃ SO ₃ , Li(CF ₃ SO ₂ ) ₂ N, Li(C ₂ F ₅ SO ₂ ) ₂ N, Li(C ₄ F ₉ SO ₂ ) ₂ N, Li(CF ₃ SO ₂ ) ₃ C, etc., Li(CF ₃ SO ₂ ) ₂ N, Li(C ₂ F ₅ SO ₂ ) ₂ N, Li(C ₄ F ₉ SO ₂ ) ₂ The fluorine-containing lithium sulfinium salt of N or the like is preferred, and the lithium salt of (perfluoroalkylsulfonyl) ruthenium is particularly preferred.

Further, examples of the alkali metal inorganic salt include lithium perchlorate and lithium iodide.

The alkali metal salt content in the adhesive is preferably 0.001 to 5 parts by weight based on 100 parts by weight of the base polymer. When the amount of the alkali metal salt is less than 0.001 part by weight, the effect of improving the antistatic property may be insufficient. The alkali metal salt is preferably 0.01 parts by weight or more, more preferably 0.1 part by weight or more. On the other hand, when the amount of the alkali metal salt is more than 5 parts by weight, the durability may be insufficient. The alkali metal salt is preferably 3 parts by weight or less.

The method of forming the adhesive layer can be produced, for example, by applying the above-mentioned adhesive to a release-treated separator or the like, drying the polymerization solvent or the like to form an adhesive layer, and then transferring it to one side. A method of protecting the polarizer side of the polarizing film (the polarizing member in the aspect of FIG. 1), or a method of forming the adhesive layer on the side of the polarizer after applying the adhesive and drying to remove the polymerization solvent or the like. Further, the application of the adhesive may be appropriately added with one or more solvents other than the polymerization solvent.

Although the thickness of the adhesive layer is not particularly limited, it is preferably 25 μm or less, more preferably 23 μm or less, based on the viewpoint of effectively suppressing defects caused by the nano slit, and taking into consideration excellent antistatic function and reworkability. It is 20 μm or less; more preferably, it is 10 μm or more, more preferably 12 μm or more, and still more preferably 15 μm or more.

It is preferred to use a polyfluorene stripping liner for the release treated separator. In the step of applying the adhesive of the present invention to the lining material and drying it to form an adhesive layer, the method of drying the adhesive may be carried out in a suitable and appropriate manner for the purpose. A method of subjecting the above coating film to superheat drying is preferably employed. The heating and drying temperature is preferably from 40 ° C to 200 ° C, more preferably from 50 ° C to 180 ° C, and particularly preferably from 70 ° C to 170 ° C. By setting the heating temperature within the above range, an adhesive having excellent adhesive properties can be obtained.

The drying time can be appropriately selected for a suitable period of time. The drying time is preferably from 5 seconds to 20 minutes, more preferably from 5 seconds to 10 minutes, and particularly preferably from 10 seconds to 5 minutes.

Various methods can be employed for the formation of the adhesive layer. Specific examples thereof include roll coating, contact roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip coating, bar coating, knife coating, and air knife coating. A cloth method, a curtain coating method, a lip coating method, a squeeze coating method using a die coater or the like.

When the aforementioned adhesive layer is exposed, the adhesive-treated sheet (separator) can be used to protect the adhesive layer until it is ready for practical use.

Examples of the constituent material of the separator include plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester film; porous materials such as paper, cloth, and non-woven fabric; and mesh and foamed sheets. A suitable sheet such as a metal foil or a laminate thereof, etc., is preferably a plastic film from the viewpoint of excellent surface smoothness.

The plastic film is not particularly limited as long as it can protect the adhesive layer, and examples thereof include a polyethylene film, a polypropylene film, a polybutene film, a polypentadiene film, a polymethylpentene film, and a polyvinyl chloride. Film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate film, and the like.

The thickness of the separator is usually 5 to 200 μm, and preferably about 5 to 100 μm. The release member may be subjected to mold release and antifouling treatment using a polyfluorene-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, bismuth powder, and the like, and a coating type or a kneading type. Antistatic treatment such as vapor deposition type. In particular, by appropriately performing a release treatment such as a polyfluorination treatment, a long-chain alkyl treatment, or a fluorine treatment on the surface of the separator, the peeling property from the adhesion of the pressure-sensitive adhesive layer can be further improved.

<Surface Protective Film> A surface protective film can be provided on the one side of the adhesive layer to protect the polarizing film. The surface protective film usually has a substrate film and an adhesive layer, and the polarizer is protected through the adhesive layer.

The base film of the surface protective film may be selected to have an isotropic or nearly isotropic film material based on the viewpoints of inspection property and management. The film material may, for example, be a polyester resin such as a polyethylene terephthalate film, a cellulose resin, an acetate resin, a polyether oxime resin, a polycarbonate resin, or a polyamide resin. A polymer which is transparent like a polyimide resin, a polyolefin resin, or an acrylic resin. Among them, polyester-based resins are preferred. The base film may be used as a laminate of one type or two or more types of film materials, or an extension of the above film may be used. The thickness of the base film is usually 500 μm or less, and preferably 10 to 200 μm.

The adhesive for forming the adhesive layer of the surface protective film can be appropriately selected from (meth)acrylic polymers, polyoxynitride polymers, polyesters, polyurethanes, polyamines, polyethers, fluorines, and the like. A polymer such as a rubber is used as an adhesive for the base polymer. From the viewpoints of transparency, weather resistance, heat resistance and the like, an acrylic adhesive having an acrylic polymer as a base polymer is preferred. The thickness of the adhesive layer (dry film thickness) can be determined by the desired adhesion. Usually it is about 1~100μm, preferably 5~50μm.

Further, in the surface protective film, a release treatment layer may be provided on a surface of the base film opposite to the surface on which the pressure-sensitive adhesive layer is provided by a low-adhesion material such as polyfluorination treatment, long-chain alkyl treatment or fluorine treatment.

<Other optical layer> The single-sided protective polarizing film of the adhesive layer of the present invention can be used as an optical film laminated with other optical layers when actually used. The optical layer is not particularly limited, and one or two or more layers such as a reflecting plate and a semi-transmissive plate, a phase difference plate (including 1/2 and 1/4 wavelength plates), a viewing angle compensation film, or the like can be used for formation. An optical layer such as a liquid crystal display device. More preferably, the single-sided protective polarizing film of the adhesive layer of the present invention is a reflective polarizing film or a semi-transmissive polarizing film which is formed by laminating a reflecting plate or a semi-transmissive reflecting plate, and is protected by one side of the adhesive layer. An elliptically polarizing film or a circularly polarizing film formed by laminating a phase difference plate of a film, a wide viewing angle polarizing film formed by laminating a viewing angle compensation film on a single-sided protective polarizing film with an adhesive layer, or a single side of an adhesive layer A polarizing film formed by protecting a polarizing film and further enriching the film.

An optical film formed by laminating the above-mentioned optical layer on a single-sided protective polarizing film with an adhesive layer may be formed by sequentially laminating in a manufacturing process of a liquid crystal display device or the like, but an optical film is laminated in advance. It is advantageous in terms of quality stability and assembly work, and has an advantage of improving manufacturing steps of a liquid crystal display device or the like. A suitable attachment mechanism such as an adhesive layer can be used for lamination. When the single-sided protective polarizing film with the above-mentioned adhesive layer and the other optical layers are next, the optical axes thereof can be set to an appropriate arrangement angle in accordance with the phase difference characteristics to be obtained.

The one-side protective polarizing film or optical film to which the adhesive layer of the present invention is applied can be suitably used for formation of various image display devices such as a liquid crystal display device and an organic EL display device. The formation of the liquid crystal display device can be carried out in accordance with conventional knowledge. In other words, the liquid crystal display device is generally formed by appropriately assembling a liquid crystal element, a single-sided protective polarizing film or an optical film of an adhesive layer, and an optional illumination system, and assembling them into a driving circuit. The present invention is not particularly limited except for the one-side protective polarizing film or optical film using the adhesive layer of the present invention, and it is customary. For the liquid crystal cell, any type such as IPS type, VA type, or the like can be used, but the IPS type is particularly preferable.

A liquid crystal display device in which a single-sided protective polarizing film or an optical film with an adhesive layer is disposed on one side or both sides of the liquid crystal element, or a liquid crystal display device such as a backlight or a reflector for an illumination system can be formed. At this time, the single-sided protective polarizing film or optical film of the adhesive layer of the present invention may be disposed on one side or both sides of the liquid crystal cell. When a single-sided protective polarizing film or an optical film with an adhesive layer is disposed on both sides, the same may be the same or different. Further, when forming a liquid crystal display device, appropriate components such as a diffusion plate, an anti-glare layer, an anti-reflection film, a protective plate, a ruthenium array, a lens array sheet, a light diffusion plate, and a backlight may be disposed at appropriate positions. Layer or more than 2 layers.

<Continuous Manufacturing Method of Image Display Device> The image display device described above is preferably manufactured by a continuous manufacturing method (cow-on-face method), which comprises the steps of: protecting a polarizing film from one side of the adhesive layer of the present invention The one-side protective polarizing film of the above-mentioned adhesive layer which is released from the winding body and conveyed by the separating member is continuously adhered to the surface of the image display panel through the adhesive layer. Since the one-side protective polarizing film of the adhesive layer of the present invention is a very thin film, if it is cut into a sheet shape (sheet cutting), one piece is attached to the image display panel (also referred to as a film) The "sheet to panel method" is difficult to handle when transporting sheets or attaching to a display panel, so that the one-sided protective polarizing film (sheet) with the adhesive layer is subjected to the process. The risk of large mechanical shocks (such as bending caused by adsorption, etc.) increases. In order to reduce such a risk, it is necessary to take measures such as using a surface protective film having a thickness of a base film having a thickness of 50 μm or more. However, according to the roll-to-face method, it is not necessary to cut the single-sided protective polarizing film with the adhesive layer into a sheet shape (sheet cut), but to stably transport the roll member from the roll member to the image display panel using a continuous state separation member and directly Bonding to the image display panel eliminates the risk of using a thicker surface protection film. As a result, in addition to the use of the adhesive layer which has been controlled so that the film thickness and the storage elastic modulus satisfy the predetermined relationship, the mechanical impact can be alleviated, and the image display panel which is effectively suppressed by the nano slit can be continuously produced at a high speed.

Fig. 5 is a schematic view showing an example of a continuous liquid crystal display device manufacturing system using a web-to-surface method. As shown in FIG. 5, the continuous manufacturing system 100 of the liquid crystal display device includes a transport unit X that transports one of the liquid crystal display panels P, a first polarizing film supply unit 101a, a first bonding unit 201a, and a second polarizing film supply unit 101b. And the second bonding unit 201b. Further, the wound body (first roll) 20a of the single-sided protective polarizing film of the first adhesive layer and the wound body (second roll) 20b of the single-sided protective polarizing film of the second adhesive layer It is used in the case where the longitudinal direction has an absorption axis and is as described in FIG.

(Transporting Unit) The conveying unit X conveys the liquid crystal display panel P. The transport unit X is configured by a plurality of transport rollers, an adsorption plate, and the like. The transport unit X includes an arrangement replacing unit 300 for replacing the long side and the short side of the liquid crystal display panel P with respect to the liquid crystal display panel P between the first bonding unit 201a and the second bonding unit 201b. The arrangement relationship of the conveying direction (for example, the liquid crystal display panel P is rotated horizontally by 90°). Thereby, the single-sided protective polarizing film 21a of the first adhesive layer and the single-sided protective polarizing film 21b of the second adhesive layer can be bonded to each other with respect to the liquid crystal display panel P in the form of orthogonal polarization.

(1st Polarized Film Supply Unit) The first polarizing film supply unit 101a is a single-sided protective polarizing film (surface protective film) 21a of the first adhesive layer which is released from the first roll 20a and is transported by the separator 5a. It is continuously supplied to the first bonding unit 201a. The first polarizing film supply unit 101a includes a first release portion 151a, a first cut portion 152a, a first peeling portion 153a, a first winding portion 154a, a plurality of transport roller portions, a collecting portion such as a floating roller, and the like.

The first release portion 151a has a single-sided protective polarizing film 21a on which the release shaft of the first web 20a can be disposed, and the strip-shaped adhesive layer provided with the separator 5a can be released from the first web 20a.

The first cutting unit 152a has a cutting mechanism such as a cutter or a laser device and an adsorption mechanism. The first cut portion 152a can retain the separator 5a while simultaneously cutting the single-sided protective polarizing film 21a of the strip-shaped first adhesive layer in the width direction by a predetermined length. However, a single-sided protective polarizing film 21a (an optical film roll having a cut mark) having a tape-like adhesive layer in which a plurality of cutting lines are formed in a predetermined length in the width direction is laminated on the separating member 5a. When the first roll 20a is used, the first cut portion 152a (the same as the second cut portion 152b to be described later) is unnecessary.

The first peeling portion 153a is formed by folding the separator 5a toward the inside to peel off the single-sided protective polarizing film 21a of the first adhesive layer from the separator 5a. The first peeling portion 153a may be a wedge member or a roller member.

The first winding unit 154a winds up the separator 5a from which the single-sided protective polarizing film 21a of the first pressure-sensitive adhesive layer has been peeled off. The first take-up portion 154a has a take-up shaft and the take-up shaft is provided with a roller member for taking up the separating member 5a.

(First Bonding Portion) The first bonding portion 201a transmits the single-sided protective polarizing film 21a of the first adhesive layer that has been peeled off via the first peeling portion 153a, and the single-sided protective polarizing film 21a that has passed through the first adhesive layer. The adhesive layer is continuously bonded to the liquid crystal display panel P transported by the transport unit X (first bonding step). The first bonding portion 81 is configured by a pair of bonding rollers, and at least one of the bonding rollers is configured by a driving roller.

(Second polarizing film supply unit) The second polarizing film supply unit 101b is a single-sided protective polarizing film (surface-protected film) 21b of the second adhesive layer which is released from the second roll 20b and transported by the separator 5b. It is continuously supplied to the second bonding portion 201b. The second polarizing film supply unit 101b includes a second release portion 151b, a second cut portion 152b, a second peeling portion 153b, a second winding portion 154b, an integrated portion of a plurality of transport roller portions, a floating roller, and the like. In addition, each of the second release portion 151b, the second cut portion 152b, the second peeling portion 153b, and the second winding portion 154b is different from the first release portion 151a, the first cut portion 152a, and the first peeling portion 153a. The first winding unit 154a has the same configuration and function.

(Second Bonding Portion) The second bonding portion 201b transmits the single-sided protective polarizing film 21b of the second adhesive layer peeled off via the second peeling portion 153b to the one-side protective polarizing film 21b of the second adhesive layer. The adhesive layer is continuously bonded to the liquid crystal display panel P transported by the transport unit X (second bonding step). The second bonding portion 201b is configured by a pair of bonding rollers, and at least one of the bonding rollers is configured by a driving roller. Example

The invention is illustrated by the following examples, but the invention is not limited by the examples shown below. In addition, parts and % in each case are based on weight. Hereinafter, the room temperature standing conditions which are not specifically defined are all 23 ° C and 65% RH.

<Preparation of single-sided protective polarizing film> (Production of polarizer) Amorphous isocyanic acid copolymerized polyethylene terephthalate (IPA copolymerized PET) film having a water absorption of 0.75% and a Tg of 75 ° C (thickness: 100 μm) A corona treatment was applied to one side of the substrate, and the corona-treated surface was coated at 25 ° C to contain polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetamidine at a ratio of 9:1. A modified aqueous solution of PVA (degree of polymerization: 1200, acetylated ethyl sulfonate degree 4.6%, saponification degree: 99.0 mol% or more, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gohsefimer Z200") and dried to form a thickness of 11 μm. A PVA-based resin layer is used to form a laminate. The obtained laminate was subjected to a uniaxial extension of the free end 2.0 times in the longitudinal direction (longitudinal direction) between the rolls having different circumferential speeds in an oven at 120 ° C (air assisted elongation treatment). Next, the laminate was immersed in an insoluble bath (boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 30 ° C for 30 seconds (insoluble treatment). Further, it was immersed in a dye bath at a liquid temperature of 30 ° C while adjusting the iodine concentration and the immersion time so that the polarizing plate reached a predetermined transmittance. In the present embodiment, it was immersed in an aqueous iodine solution obtained by blending 0.2 part by weight of iodine with respect to 100 parts by weight of water and blending 1.0 part by weight of potassium iodide for 60 seconds (dyeing treatment). Next, it was immersed in a crosslinking bath at a liquid temperature of 30 ° C (with respect to 100 parts by weight of water, a boric acid aqueous solution obtained by blending 3 parts by weight of potassium iodide and blending 3 parts by weight of boric acid) for 30 seconds (crosslinking treatment) ). Then, the laminate was immersed in a boric acid aqueous solution having a liquid temperature of 70 ° C (an aqueous solution obtained by blending 4 parts by weight of boric acid with 5 parts by weight of potassium iodide with respect to 100 parts by weight of water), and the rolls were different at a peripheral speed. The cylinders are uniaxially stretched in the longitudinal direction (longitudinal direction) so that the total stretching ratio is 5.5 times (water stretching treatment). Thereafter, the laminate was immersed in a washing bath at a liquid temperature of 30° C. (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) (washing treatment). Through the above procedure, an optical film laminate including a polarizer having a thickness of 5 μm and a boric acid content of 16% was obtained. The boric acid content in the polarizer was measured by the following method.

For the obtained polarizer, a boronic acid peak (665 cm ^-1 ) was measured by a Fourier transform infrared spectrophotometer (FTIR) (manufactured by Perkin Elmer Co., Ltd., trade name "SPECTRUM2000") using attenuated total reflection spectrometry (ATR) measurement using polarized light as measurement light. ) Strength and reference peak (2941 cm ^-1 ) intensity. The boric acid amount 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 amount 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 amount index) × 5.54 + 4.1

(Production of Transparent Protective Film) Transparent Protective Film: The easy-to-treat surface of a (meth)acrylic resin film having a lactone ring structure having a thickness of 40 μm was subjected to corona treatment and then used.

(Preparation of an adhesive applied to a transparent protective film) 40 parts by weight of N-hydroxyethyl acrylamide (HEAA), 60 parts by weight of acryloyl phenylephrine (ACMO) and a photoinitiator "IRGACURE 819" (BASF) 3 parts by weight of the company's product was blended to prepare an ultraviolet curable adhesive.

<Preparation of the one-side protective polarizing film> The ultraviolet curable adhesive is applied to the surface of the polarizer of the optical film laminate, and the thickness of the adhesive layer after curing is 0.5 μm. The transparent protective film is then irradiated with ultraviolet rays as an active energy ray to harden the adhesive. The ultraviolet ray is a metal halide lamp filled with gallium, and the illuminating device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., bulb: V bulb, peak illuminance: 1600 mW/cm ² , cumulative irradiation amount 1000/mJ/cm ² (wavelength 380 to 440 nm), and the ultraviolet illuminance was measured using a Sola-Check system manufactured by Solatell. Next, the amorphous PET substrate was peeled off to produce a one-side protective polarizing film using a thin polarizer. Using the obtained single-sided protective polarizing film, after measuring the single transmittance T and the degree of polarization P of the polarizer, the single transmittance T of the polarizer was 42.8%, and the polarization P of the polarizer was 99.99%. .

The single transmittance T and the degree of polarization P of the polarizer of the obtained single-sided protective polarizing film were measured using a spectroscopic transmittance measuring instrument (Dot-3c of Murakami Color Research Institute) with an integrating sphere. Further, the degree of polarization P is a transmittance (parallel transmittance: Tp) when two single-sided protective polarizing films are overlapped in parallel with the transmission axes of the two, and a transmittance when the transmission axes of the two are orthogonally overlapped ( Vertical transmittance: Tc) is obtained by applying the following formula. Polarization P(%)={(Tp-Tc)/(Tp+Tc)} ^1/2 ×100 Each transmittance is 100% of the total polarization obtained by the Glan-Taylor polarizer. And the Y value obtained by the optical performance correction by the 2 degree field of view (C light source) of JIS Z8701.

<Formation of Adhesive Layer> (Preparation of Acrylic Adhesive A) 93.82 parts of n-butyl acrylate, 4 parts of methyl methacrylate, 1.5 parts of N-vinylpyrrolidone, 0.2 parts of acrylic acid and A monomer mixture of 0.48 parts of 4-hydroxybutyl acrylate was fed into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction tube, and a cooler. Then, 0.15 parts of 2,2 ́-azobisisobutyronitrile as a polymerization initiator was fed together with ethyl acetate with respect to 100 parts of the above-mentioned monomer mixture (solid content), and nitrogen gas was introduced while stirring slowly. After the nitrogen substitution, the liquid temperature in the flask was maintained at about 60 ° C, and the polymerization reaction was carried out for 7 hours. Thereafter, ethyl acetate was added to the obtained reaction liquid to prepare an acrylic polymer solution having a solid content adjusted to a concentration of 20% and a weight average molecular weight of 1.3 million.

The weight average molecular weight (Mw) of the acrylic polymer was measured using a GPC apparatus (HLC-8220GPC) manufactured by Tosoh Co., Ltd. The measurement conditions are as follows. Sample concentration: 0.2% by mass (THF solution) Sample injection amount: 10 μl Eluent: THF Flow rate: 0.6 ml/min Measurement temperature: 40 ° C Column: sample column; TSKguardcolumn SuperHZ-H (1) + TSKgel SuperHZM-H (2) Reference column; TSKgel SuperH-RC (1) Detector: Differential refractometer (RI) The weight average molecular weight is determined in terms of polystyrene.

1.5 parts of lithium bis(trifluoromethanesulfonyl) ruthenium (manufactured by Mitsubishi Materials Electronics Co., Ltd.) and 1 part of ethyl methyl group were blended with respect to 100 parts of the solid content of the prepared acrylic polymer solution. Pyrrolidinium-bis(trifluoromethanesulfonyl) ruthenium (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.17 parts of isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name "TAKENATE D160N"), and 0.25 parts of peroxidation The acrylic adhesive A was prepared by using a cross-linking agent (manufactured by Nippon Oil Co., Ltd., trade name "NYPER BMT") and 0.1 part of a heavy duty lifting agent (manufactured by Kaneka Co., Ltd., trade name "SAT10").

(Preparation of Acrylic Adhesive B to I) The monomer composition when the acrylic adhesive A was prepared was changed to the polymerization conditions as shown in Table 1, and the acrylic polymer was prepared in the same manner. The solution was prepared to prepare an acrylic adhesive B~I.

(Formation of Adhesive Layer) Next, the prepared acrylic adhesives A to I were uniformly applied to a poly(ethylene terephthalate)-treated polyethylene terephthalate by a spray coater. The surface of the film (separation film) was dried in an air circulating oven at 155 ° C for 1 minute, and an adhesive layer was formed on each of the separation film surfaces.

[Table 1]

The compounds in Table 1 are as follows. BA: n-butyl acrylate MMA: methyl methacrylate NVP: N-vinylpyrrolidone AA: acrylic acid 4HBA: 4-hydroxybutyl acrylate LiTFSi: lithium bis(trifluoromethanesulfonyl) quinone imine (Mitsubishi EMPTFSi: Ethylmethylpyrrolidinium-bis(trifluoromethanesulfonyl) ruthenium (made by Tokyo Chemical Industry Co., Ltd.) SAT10: Heavy Duty Lifting Agent (Kaneka Co., Ltd.)

Examples 1 to 11 and Comparative Examples 1 and 2 <Production of a single-sided protective polarizing film with an adhesive layer> The adhesive layers thus produced were respectively attached to the polarizing member side of the produced single-sided protective polarizing film. A single-sided protective polarizing film with an adhesive layer was separately produced.

The following measurement and evaluation were performed on the one-side protective polarizing film obtained by the above-mentioned adhesive layer and adhesive layer. The results are shown in Table 2.

<Measurement of Peak Absorbance> For the adhesive layer side of the one-side protective polarizing film of the obtained adhesive layer, a Fourier transform infrared spectrophotometer (FTIR) (manufactured by Perkin Elmer Co., Ltd., trade name "FT-IR Spectrometer Frontier" was used. The total absorbance was measured by the total reflection measurement (ATR) on the stretching vibration derived from the ester bond of the monomer component in the adhesive. The measurement was carried out under the conditions of 8 cumulative times and a resolution of -4 cm ^-1 . The peak of the absorbance in the range of 1100 to 1130 cm ^-1 is taken as the peak absorbance Abs(a) of the asymmetric stretching vibration derived from the COC bond of methyl (meth) acrylate, and the absorbance in the range of 1150 to 1260 cm ^-1 . The peak value is the peak absorbance Abs(b) of the asymmetric stretching vibration derived from the COC bond of the alkyl (meth)acrylate, and the lowest absorbance (baseline) in the range of 800 to 900 cm ^-1 is taken as the absorbance Abs(c). . Then, the obtained absorbance was substituted into the following formula to calculate an IR parameter.

<Suppression of occurrence of nano slits: guitar shrapnel test> The one-side protective polarizing film of the adhesive layer obtained in the examples and the comparative examples was cut into a size of 50 mm × 150 mm (the absorption axis direction was 50 mm) as Sample 11. The sample 11 was used by bonding the surface protection film 6 produced by the following method to the side of the protective film 2.

(Surface protection film for test) 94 parts by mass of 2-ethylhexyl acrylate (2EHA), 1 part by mass of N,N-diethyl acrylamide (DEAA), and 1 part by mass of ethoxylated Ethylene glycol acrylate (EDE), 4 parts by mass of 4-hydroxybutyl acrylate (HBA), 0.2 parts by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 150 parts by mass of acetic acid The ethyl ester was fed into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler, and nitrogen gas was introduced while stirring slowly, and the liquid temperature in the flask was maintained at about 60 ° C for 5 hours. An acrylic polymer solution (40% by mass) was prepared. The acrylic polymer had a weight average molecular weight of 570,000 and a glass transition temperature (Tg) of -68 °C. The acrylic polymer solution (40% by mass) was diluted to 20% by mass with ethyl acetate, and 2 parts by mass (solid content: 2 parts by mass) was added to 500 parts by mass (100 parts by mass of solid content) of this solution. Dimer isocyanate of hexamethylene isocyanate (Coronate HX: C/HX, manufactured by Polyurethane Industrial Co., Ltd., Japan), and 2 parts by mass (solid content: 0.02 parts by mass) of dilauric acid as a crosslinking catalyst The butyl tin (1 mass% ethyl acetate solution) was mixed and stirred to prepare an acrylic adhesive solution. The acrylic adhesive solution was applied to a transparent polyethylene terephthalate (PET) film (polyester film) having a thickness of 38 μm, and heated at 130 ° C for 1 minute to form an adhesive layer having a thickness of 15 μm. Surface protection film.

Next, as shown in the conceptual diagram of FIG. 3(A) and the cross-sectional view of FIG. 3(B), the release sheet (separator) is peeled off from the sample 11 and attached to the glass sheet through the exposed adhesive layer 4. 20 on. Then, a guitar shrap (manufactured by HISTORY, model "HP2H (HARD)") was applied with a load of 200 g on the center portion of the sample 11 (the side of the surface protective film 6), and was perpendicular to the absorption axis of the polarizing member 1 of the sample 11. Repeat 50 times of load loading with a distance of 100mm. The aforementioned load loading is performed at one place. Further, the load loading was performed at a high speed (5 m/min). Next, after the sample 11 was left to stand in an environment of 80 ° C for 1 hour, it was confirmed from the following criteria whether or not the sample 11 was cracked by light leakage. ◎: 0~10 ○: 11~30 × ×: 31 or more

4 is an example of a micrograph of the surface of the polarizing film, which is the following indicator for confirming the light leakage crack (nano slit a) of the single-sided protective polarizing film 11 with the adhesive layer in the guitar spring test. In Fig. 4(A), the light leakage crack caused by the nano slit a was not confirmed. In addition, FIG. 4(B) is a case where light leakage cracks caused by three nano slits a are generated in the absorption axis direction of the polarizer via heating. Fig. 4 is a view showing a sample having a nano slit produced under an interference phase contrast microscope. When the sample was taken, the sample produced by the nanometer slit was placed on the lower side (light source transmission side) of the sample having the nano slit, and was observed by the transmitted light.

<Evaluation of Reworkability> The one-side protective polarizing film of the prepared adhesive layer was cut into 32 Å as a sample. The sample was attached to an alkali-free glass plate using a laminator, and then autoclaved at 50 ° C and 5 atm for 15 minutes to be completely adhered. Thereafter, the adhesion (N/25 mm) at the time of rework under the conditions of a peeling angle of 90° and a peeling speed of 300 mm/min was measured using a rework device. Then, the evaluation was performed according to the following criteria. ◎: 3 (N/25 mm) or less ○: Greater than 3 (N/25 mm) and 6 (N/25 mm) or less ×: Greater than 6 (N/25 mm)

<Evaluation of Antistatic Property> After the separation film of the one-side protective polarizing film with the adhesive layer produced was peeled off, the surface resistance value of the surface of the adhesive was measured using MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd. (Ω/ □). The one-side protective polarizing film with the adhesive layer produced was cut into a size of 100 mm × 100 mm, and attached to the liquid crystal panel. This panel was placed on a backlight having a brightness of 10,000 cd, and electrostatic generation device ESD (ESD-8012A, manufactured by SANKI Corporation) was used to generate static electricity of 15 kV, thereby causing alignment disorder of the liquid crystal. The instantaneous multi-point photometric detector (MCPD-3000, manufactured by Otsuka Electronics Co., Ltd.) was used to measure the recovery time (seconds) of the display failure caused by the misalignment. Then, the evaluation was performed according to the following criteria. ◎: Within 5 seconds. ○: more than 5 seconds and less than 7 seconds △: more than 7 seconds and less than 10 seconds ×: more than 10 seconds

[Table 2]

As can be seen from Table 2, the one-side protective polarizing film of the adhesive layers of Examples 1 to 11 was less likely to cause cracks, and had excellent reworkability and antistatic function. On the other hand, it was found that the one-side protective polarizing film of the adhesive layers of Comparative Examples 1 and 2 was inferior in any of the crack preventing function, the reworkability, and the antistatic function.

INDUSTRIAL APPLICABILITY The single-sided protective polarizing film with an adhesive layer of the present invention can be used for an image display device such as a liquid crystal display device (LCD) or an organic EL display device, either alone or in an optical film laminated thereon. .

1‧‧‧ polarizer

2‧‧‧Protective film

3‧‧‧Binder layer, etc.

4‧‧‧Adhesive layer

5, 5a, 5b‧‧‧ separate parts

6, 6a, 6b‧‧‧ surface protection film

10‧‧‧Single-sided protective polarizing film

11‧‧‧Single-sided protective polarizing film with adhesive layer

20‧‧‧ glass plate

20a‧‧‧1st wound body of single-sided protective polarizing film with adhesive layer (1st roll)

20b‧‧‧The second wound body of the single-sided protective polarizing film with adhesive layer (volume 2)

21a‧‧‧1st single-sided protective polarizing film with adhesive layer (with surface protection film)

21b‧‧‧2nd single-sided protective polarizing film with adhesive layer (with surface protection film)

100‧‧‧Continuous manufacturing system for image display devices (liquid crystal display devices)

101a‧‧‧1st polarizing film supply unit

101b‧‧‧2nd polarizing film supply unit

151a‧‧‧1st release

151b‧‧‧2nd release

152a‧‧‧1st cutting department

152b‧‧‧2nd Cutting Department

153a‧‧‧1st peeling section

153b‧‧‧2nd peeling section

154a‧‧‧1st Volume

154b‧‧‧2nd Volume

201a‧‧‧1st fitting department

201b‧‧‧2nd Fittings

300‧‧‧Configuration Replacement Department

P‧‧‧ image display panel

X‧‧‧Transmission Department of Image Display Panel

a‧‧‧Nan slit

B‧‧‧through cracks

Fig. 1 is a schematic cross-sectional view showing a one-side protective polarizing film with an adhesive layer of the present invention. Fig. 2 is a view showing an example of a conceptual diagram of a nano slit and a penetrating crack formed in a polarizing member. Fig. 3 is a schematic view showing the evaluation items of the nanoslit correlation of the examples and the comparative examples. Fig. 4 is a photograph showing an example of a crack generated by the nano slit according to the evaluation of the examples and the comparative examples. Fig. 5 is a schematic cross-sectional view showing an example of a continuous manufacturing system of the image display device.

Claims (12)

An adhesive layer characterized in that it contains a (meth)acrylic polymer as a base polymer; and the (meth)acrylic polymer contains an alkyl group having a carbon number of 2 to 12 (meth)acrylic acid An alkyl ester and methyl (meth) acrylate are used as a monomer unit, and the aforementioned adhesive layer satisfies the following formula (1): Abs(a): is the peak absorbance of the asymmetric stretching vibration derived from the COC bond of methyl (meth) acrylate in the IR measurement by the total reflection measurement method of the above-mentioned adhesive layer; Abs(b): The above-mentioned adhesive layer is derived from the peak absorbance of the asymmetric stretching vibration of the COC bond of the alkyl (meth)acrylate in the IR measurement by the total reflection measurement method; Abs(c): the aforementioned adhesive layer The lowest absorbance in the range of 800 to 900 cm ^-1 in the IR measurement by the total reflection measurement method. The adhesive layer of claim 1, wherein the aforementioned adhesive layer contains an alkali metal salt. The adhesive layer of claim 1 or 2, wherein the adhesive layer comprises a heavy duty enhancer. The adhesive layer according to any one of claims 1 to 3, wherein the thickness of the adhesive layer is 25 μm or less. A single-sided protective polarizing film with an adhesive layer, having a single-sided protective polarizing film having a protective film on only one side of the polarizing member, and directly having the polarizing member side of the single-sided protective polarizing film as claimed in claims 1 to 4 The adhesive layer of any one of claims 1 to 4, or the adhesive layer of any one of claims 1 to 4. The one-side protective polarizing film of the adhesive layer of claim 5, wherein the polarizing member has a thickness of 12 μm or less. The one-side protective polarizing film of the adhesive layer of claim 5 or 6, wherein the polarizer comprises a polyvinyl alcohol-based resin, and the optical characteristics represented by the single transmittance T and the polarization P satisfy the following formula; Conditions: P>-(10 ^0.929T-42.4 -1) × 100 (only, T < 42.3), or P ≧ 99.9 (only, T ≧ 42.3). The one-side protective polarizing film with an adhesive layer according to any one of claims 5 to 7, wherein the polarizing member contains boric acid of 25% by weight or less based on the total amount of the polarizing member. The one-side protective polarizing film of the adhesive layer according to any one of claims 5 to 8, which is provided with a separating member in the above-mentioned adhesive layer. The one-side protective polarizing film of the adhesive layer of claim 9 is a wound body. An image display device having a single-sided protective polarizing film with an adhesive layer as claimed in any one of claims 5 to 8. A continuous manufacturing method of an image display device comprising the steps of: releasing the above-mentioned adhesive layer which is released from a wound body of a single-sided protective polarizing film of the above-mentioned adhesive layer as claimed in claim 10 and conveyed by the aforementioned separating member The single-sided protective polarizing film is continuously attached to the surface of the image display panel through the adhesive layer.