TWI812726B - Single-sided protective polarizing film with adhesive layer, image display device and continuous manufacturing method thereof - Google Patents

Abstract

The object of the present invention is to provide a single-sided protective polarizing film with an adhesive layer, which is excellent in initial reworkability, durability and conductive stability in high temperature and/or high humidity environments, and which can occur even when exposed to It is not easy to peel off from glass substrates, etc. even in condensation environments. The single-sided protective polarizing film with an adhesive layer of the present invention has: the single-sided protective polarizing film has a protective film only on one side of the polarizer; and the single-sided protective polarizing film has an adhesive layer directly on the side of the polarizer. agent layer or an adhesive layer across the coating layer; the adhesive layer contains a (meth)acrylic polymer as a base polymer, has a weight change rate of 1.1% or more, and has an adhesive force of P ₀ before being immersed in water. It is less than 10N/25mm, and the adhesive force _P1 after being immersed in water for 2 hours is more than 1.6N/25mm.

Description

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

The invention relates to a single-sided protective polarizing film with an adhesive layer, which has a single-sided protective polarizing film and an adhesive layer provided with a protective film only on one side of a polarizer. The aforementioned single-sided protective polarizing film with an adhesive layer can be used alone or in the form of an optical film laminated thereto to form an image display device such as a liquid crystal display device (LCD) or an organic EL display device.

Background of the invention In a liquid crystal display device, depending on the image forming method, it is necessary and indispensable to arrange polarizing films on both sides of the glass substrate that forms the surface of the liquid crystal panel. The polarizing film generally used is a polarizing element composed of a polyvinyl alcohol-based film and a dichroic material such as iodine, and is laminated with a protective film through a polyvinyl alcohol-based adhesive or the like on one or both sides.

When the aforementioned polarizing film is attached to a liquid crystal cell or the like, an adhesive is usually used. In addition, the adhesive is pre-disposed on one side of the polarizing film in the form of an adhesive layer, which has the advantages of instantly fixing the polarizing film and fixing the polarizing film without a drying step. That is, the polarizing film attached uses a polarizing film attached with an adhesive layer.

In addition, the polarizing film or the polarizing film with the adhesive layer is exposed to the harsh environment of thermal shock (such as the thermal shock test with repeated temperature conditions of -30°C and 80°C or the test at a high temperature of 100°C), and there is shrinkage stress of the polarizer. Changes cause the problem of cracks (penetrating cracks) in the entire absorption axis direction of the polarizer. That is, the durability of the polarizing film or the polarizing film with the adhesive layer against thermal shock in the aforementioned harsh environment is not sufficient. In particular, from the viewpoint of thinning, a single-sided protective polarizing film using an adhesive layer in which a protective film is provided on only one side of the polarizer is not sufficiently durable against the thermal shock. Moreover, penetrating cracks caused by the aforementioned thermal shock are likely to occur when the size of the polarizing film increases.

For example, in order to provide high durability in high-temperature environments, some literature proposes to use those with a storage elastic modulus at 23°C of 0.2~10MPa and a thickness of 2 μm or more and less than 25 μm as a single-sided protection of the adhesive layer. Adhesive layer of polarizing film (Patent Document 1). In addition, in order to provide good durability in high-temperature environments, some literature proposes a polarizing plate in which a pressure-sensitive adhesive layer is provided on one side of the polarizer and a transparent resin film is provided on the other side of the polarizer. A protective layer is formed, and the polarizing plate uses one that exhibits a storage elastic modulus of 0.15~1MPa in the temperature range of 23~80°C as the aforementioned pressure-sensitive adhesive layer (Patent Document 2). Furthermore, in order to suppress the occurrence of the above-mentioned penetrating cracks, some literature proposes to use adhesives that control the shrinkage force in the direction perpendicular to the absorption axis of the polarizer to be small and have a storage elastic modulus of the adhesive layer at 23°C of 0.20 MPa or more. , as the adhesive layer of a single-sided protective polarizing film with an adhesive layer (Patent Document 3). In addition, there are attempts to reduce the thickness of polarizers. For example, one document proposes a thin polarizer whose optical properties of single-piece transmittance and polarization are controlled and which exhibits a high degree of directionality (Patent Document 4).

However, even though Patent Document 1 has satisfactory durability, since the thickness of the polarizer is as large as 25 μm, it is impossible to prevent the polarizer from penetrating cracks caused by shrinkage stress. In addition, since Patent Documents 1 to 3 aim to improve the durability of a single-sided protective polarizing film with an adhesive layer, a large amount of boric acid is used in polarizers. It is known that when the boric acid contained in the polarizer exceeds a certain value, the cross-linking of the boric acid will be promoted during heating and the shrinkage stress of the polarizer will be increased. Therefore, it is not ideal from the perspective of suppressing the occurrence of penetrating cracks. That is, although penetrating cracks can be suppressed to a certain extent by controlling the storage elastic modulus of the adhesive layer in Patent Documents 1 to 3, they still cannot be said to be able to sufficiently suppress the occurrence of penetrating cracks.

In addition, the polarizer is also made thinner. When the polarizer used for the single-sided protective polarizing film attached to the adhesive layer is thinned, the shrinkage stress change of the polarizer will also be reduced. Therefore, it is known that the occurrence of the above-mentioned penetrating cracks can be suppressed by using a thinned polarizer.

However, it is known that when the optical properties are controlled and the polarizer is thinned as described in Patent Document 4 (for example, setting the thickness to 12μm or less), when the single-sided protective polarizing film with the adhesive layer is subjected to mechanical impact (including the load of convex bending on the side of the polarizer), extremely fine lines will be locally produced in the direction of the absorption axis of the polarizer. Slits (hereinafter also referred to as nano-slits). It is also known that the generation of the aforementioned nano-slits has nothing to do with the size of the polarizing film. It is also known that the aforementioned nano-slits will not occur when a double-sided protective polarizing film with protective films on both sides of the polarizer is used. It is also known that when penetrating cracks are formed on a polarizer, the stress around the penetrating cracks is released, so penetrating cracks are not formed adjacently, but nanoslits are formed independently and adjacently. It is also known that penetrating cracks have ductility extending along the absorption axis direction of the cracked polarizer, but nanoslits do not have the aforementioned ductility. From this, it can be seen that the aforementioned nano slit is a new issue that will arise when the polarizer is thinned and the optical properties are controlled within a predetermined range for the single-sided protective polarizing film that has suppressed the occurrence of penetrating cracks. This is because it is different from the previous one. It is well known that there are issues arising from the completely different phenomenon of penetrating cracks mentioned above.

In addition, because the aforementioned nanoslits are extremely thin, they cannot be detected in normal environments. Therefore, even if nano-slits are produced on the polarizer, it will be difficult to confirm the defect only by the light transmission of the single-sided protective polarizing film with the adhesive layer attached. That is, a single-sided protective polarizing film is usually made into a long film shape and defects are detected by automatic optical inspection. However, it is difficult to detect nano-slits as defects in this defect detection. It is known that the defects caused by the aforementioned nano-slits can occur due to the width of the nano-slits when the single-sided protective polarizing film with an adhesive layer is attached to the glass substrate of the image display panel and placed in a heated environment. The direction is expanded and detected (such as the presence or absence of light transmission mentioned above).

Therefore, in terms of using a single-sided protective polarizing film with an adhesive layer attached to a thin polarizer, it is expected to suppress defects caused by not only penetrating cracks but also nano-slits. In addition, a single-sided protective polarizing film with an adhesive layer is thinner than a double-sided protective polarizing film with protective films on both sides, so the polarizing film is prone to bending or breaking during handling.

In order to suppress the defects caused by the aforementioned nano-slits, a document proposes a technology of providing a transparent layer (coating layer) between the polarizer and the adhesive layer of a single-sided protective polarizing film with an adhesive layer (Patent Document 5) ). By providing a transparent layer, the polarizing film becomes less likely to bend when external stress is applied to the polarizing film, thereby suppressing the generation of nano-slits.

In addition, when manufacturing a liquid crystal display device, when the single-sided protective polarizing film with an adhesive layer is attached to the liquid crystal unit, the release film will be peeled off from the adhesive layer of the single-sided protective polarizing film with an adhesive layer, resulting in peeling off. The release film generates static electricity. The static electricity generated in this way affects the orientation of the liquid crystal inside the liquid crystal display device, causing defects. In addition, when the liquid crystal display device is used, display unevenness caused by static electricity may occur. The generation of static electricity can be suppressed by, for example, forming an antistatic layer on the outside of the polarizing film. However, this has little effect and has the problem of being unable to fundamentally prevent the generation of static electricity. Therefore, in order to fundamentally suppress the generation of static electricity, it is required to provide the adhesive layer with an antistatic function. As a means of imparting an antistatic function to an adhesive layer, it has been proposed, for example, to blend an ionic compound into an adhesive used to form the adhesive layer (Patent Documents 6 to 8). Specifically, Patent Document 6 proposes an adhesive composition for optical films blended with an alkali metal salt and/or an organic cation-anion salt. Patent Document 7 proposes an adhesive composition containing an onium-anion salt and an alkali metal salt as a raw material for an adhesive layer of a polarizing film to which the adhesive layer is attached. Patent Document 8 proposes an adhesive composition containing an alkali metal salt as a raw material for an adhesive layer of an adhesive polarizing plate.

In addition, the adhesive layer of a single-sided protective polarizing film with an adhesive layer is required to have high durability. For example, it is required that it does not fail in durability tests using heating and humidification that are usually conducted as environmental acceleration tests. Undesirable situations such as peeling and embossing of the adhesive layer may occur.

Various adhesive compositions for optical applications have been developed. For example, literature has proposed an adhesive composition that will prevent the optical film from peeling off even when placed under high humidity and heat conditions. Or foaming (Patent Document 9).

Advanced technical documents patent documents Patent Document 1: Japanese Patent Application Publication No. 2010-44211 Patent Document 2: Japanese Patent Application Publication No. 2008-197309 Patent Document 3: Japanese Patent Application Publication No. 2013-72951 Patent Document 4: Japanese Patent No. 4751481 Specification Patent Document 5: Japanese Patent No. 6077618 Specification Patent Document 6: Japanese Patent Application Publication No. 2015-199942 Patent Document 7: Japanese Patent Application Publication No. 2014-48497 Patent Document 8: Japanese Patent Application Publication No. 2012-247574 Patent Document 9: Japanese Patent Application Publication No. 2009-242767

Summary of the invention The problem to be solved by the invention However, the glass substrate with polarizing film, which is made by laminating a conventional single-sided protective polarizing film with an adhesive layer to a glass substrate that forms the surface of a liquid crystal panel, may be easily exposed to an environment where condensation occurs. There is a problem of peeling off at the interface between the glass substrate and the adhesive layer.

In addition, when forming a single-sided protective polarizing film with an adhesive layer attached to a glass substrate or the like on the surface of a liquid crystal panel, if foreign matter or air bubbles are mixed in and a bonding error occurs, the polarizing film must be peeled off from the glass substrate, etc. . A single-sided protective polarizing film with an adhesive layer attached to a thin polarizer is used. Since the polarizer is very thin and the protective film is only provided on one side of the polarizer, the overall thickness is quite thin. Therefore, the single-sided protective polarizing film using the adhesive layer of the conventional thin polarizer has a problem of being easily broken when peeled off from a glass substrate or the like. Therefore, the adhesive layer is also required to have reworkability that does not cause problems when peeling off the polarizing film from a glass substrate or the like.

The object of the present invention is to provide a single-sided protective polarizing film with an adhesive layer, which is excellent in initial reworkability, durability in high temperature and/or high humidity environments, and conductive stability, and which can produce condensation even when exposed to It is not easy to peel off from glass substrates, etc. even under such conditions. Moreover, in addition to the aforementioned effects, the object of the present invention is to provide a single-sided polarized protection adhesive layer that can suppress defects caused by nano-slits even if a coating layer is not provided between the polarizer and the adhesive layer. film.

Moreover, the present invention also aims to provide an image display device having a single-sided protective polarizing film with the aforementioned adhesive layer and a continuous manufacturing method thereof.

means to solve problems As a result of incisive research, the inventors of the present case found that the above problems can be solved by using the following single-sided protective polarizing film with an adhesive layer, and thus achieved the present invention.

That is, the present invention relates to a single-sided protective polarizing film with an adhesive layer, which is characterized in that: it has: a single-sided protective polarizing film, which only has a protective film on one side of the polarizer; and, as mentioned above The polarizer side of the single-sided protective polarizing film has an adhesive layer directly or through a coating layer; the adhesive layer contains a (meth)acrylic polymer as a base polymer, and the adhesive layer has the following formula (1) The calculated weight change rate is 1.1% or more, and the adhesive force P ₀ of the aforementioned adhesive layer under the following conditions is less than 10N/25mm, and the adhesive force P ₁ under the following conditions is more than 1.6N/25mm; Weight change rate (%) = {(W ₁ -W ₀ )/W ₀ }×100 (1) W ₀ =The weight of the adhesive layer after drying the aforementioned adhesive layer at 23°C for 2 hours W ₁ =The After the aforementioned drying, the aforementioned adhesive layer is placed at 23°C 55%RH for 5 hours, and after being placed at 60°C 95%RH for 5 hours. The weight adhesive force P ₀ of the adhesive layer is as follows: The adhesive layer of the surface protection polarizing film is attached to the surface of the alkali-free glass, and after being subjected to autoclave treatment at 50°C and 0.5atm for 15 minutes, the peeling temperature is 23°C, the peeling speed is 300mm/min, and the peeling angle is 90 degrees. Under the conditions, the adhesive force when the aforementioned adhesive layer is peeled off the aforementioned alkali-free glass surface; Adhesion force P ₁ : The adhesive layer of the aforementioned single-sided protective polarizing film attached to the adhesive layer is attached to the surface of the alkali-free glass, And perform autoclave treatment for 15 minutes under the conditions of 50°C and 0.5atm to prepare a laminated body. The laminated body is immersed in water of 23°C for 2 hours. The adhesive force when peeling off the aforementioned adhesive layer from the aforementioned alkali-free glass surface under the conditions of peeling speed of 300mm/min and peeling angle of 90 degrees.

In order to impart durability and conductive stability to the adhesive layer provided on the polarizer side of the single-sided protective polarizing film, it is preferable to introduce polarity into the (meth)acrylic polymer, which is the base polymer of the adhesive layer, through copolymerization. Single body. However, the hydrophilicity of (meth)acrylic polymers into which polar monomers have been introduced through copolymerization becomes higher. Therefore, the adhesive layer containing the (meth)acrylic polymer will easily absorb water when exposed to an environment where condensation occurs, and the adhesive force will easily decrease, so it will easily peel off from a glass substrate or the like. The present inventors have actively studied the relationship between the physical properties of the adhesive layer provided on the polarizer side of the single-sided protective polarizing film, initial reworkability, and peeling off from a glass substrate, etc., and found that by using the adhesive By adjusting the weight change rate of the layer before and after humidification and the adhesive force under specific conditions to a specific range, a single-sided protective polarizing film with an adhesive layer can be produced, which can improve the initial reworkability, high temperature and/or Or, while maintaining high durability and conductive stability in high-humidity environments, they are less likely to peel off from glass substrates, etc., even when exposed to environments where condensation occurs.

The aforementioned (meth)acrylic polymer preferably contains the following as monomer units: More than 50% by weight of alkyl (meth)acrylate (A), and the glass transition temperature of its homopolymer is lower than 0°C; and 0.1~20% by weight of high Tg monomer (B), which is selected from the group consisting of (meth)acrylic acid alkyl ester (b1) and (meth)acrylyl group-containing monomer (b2) At least one of them, the glass transition temperature of the homopolymer of the aforementioned (meth)acrylic acid alkyl ester (b1) is 0°C or above, and the glass of the aforementioned homopolymer of the (meth)acrylyl group-containing monomer (b2) The transition temperature is above 0°C and has a heterocyclic ring.

In addition, the (meth)acrylic polymer preferably contains a polar monomer other than the (meth)acrylyl group-containing monomer (b2) as a monomer unit, and the polar monomer system is selected from the group consisting of nitrogen-containing monomers. At least one kind from the group consisting of monomer, carboxyl group-containing monomer, hydroxyl group-containing monomer and aromatic group-containing monomer.

The aforementioned nitrogen-containing monomer is preferably a vinyl monomer having a lactam ring. In addition, the vinyl monomer having a lactam ring is preferably a vinylpyrrolidone monomer. In addition, the vinylpyrrolidone monomer is preferably N-vinylpyrrolidone.

In addition, the (meth)acrylic polymer preferably contains 0.1 to 5% by weight of the aforementioned nitrogen-containing monomer as monomer units, preferably 0.01 to 3% by weight of the aforementioned carboxyl group-containing monomer, and preferably 0.01 to 1% by weight. % by weight of the aforementioned hydroxyl group-containing monomer, and preferably 1 to 20% by weight of the aforementioned aromatic group-containing monomer.

Furthermore, the weight average molecular weight of the (meth)acrylic polymer is preferably 1.5 million or less.

The adhesive layer preferably contains a silane coupling agent, and the silane coupling agent has at least one functional group selected from the group consisting of epoxy group, isocyanate group, mercapto group, acid anhydride group and amine group. The content of the silane coupling agent is preferably 0.01 to 3 parts by weight relative to 100 parts by weight of the (meth)acrylic polymer.

The thickness of the aforementioned polarizer is preferably 12 μm or less.

In addition, the polarizing element preferably contains a polyvinyl alcohol-based resin, and is preferably configured so 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).

In addition, the aforementioned polarizer preferably contains 25% by weight or less of boric acid based on the total amount of the polarizer.

A separator may be provided on the adhesive layer of the single-sided protective polarizing film attached with the adhesive layer. The single-sided protective polarizing film with an adhesive layer provided with a separator can be used in the form of a roll.

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

In addition, the present invention relates to a continuous manufacturing method of an image display device, which includes the following steps: releasing the roll of the single-sided protective polarizing film from the adhesive layer and transporting the adhesive layer through the separator. The single-sided protective polarizing film of the agent layer is continuously attached to the surface of the image display panel through the aforementioned adhesive layer.

Invention effect Since the single-sided protective polarizing film with an adhesive layer of the present invention has excellent initial reworkability, even if a thin polarizer is used, the polarizing film can be peeled off from a glass substrate or the like without breaking. Furthermore, since the single-sided protective polarizing film with an adhesive layer of the present invention has excellent durability in high temperature and/or high humidity environments, it is less likely to cause defects such as peeling and embossing caused by the adhesive layer. Moreover, the single-sided protective polarizing film with an adhesive layer of the present invention has excellent conductive stability in a humidified environment, so the polarizing element is not prone to deterioration, and the polarizing element is not prone to fading. Moreover, even if the single-sided protective polarizing film with an adhesive layer of the present invention is exposed to an environment where condensation occurs, the adhesive force is not easily reduced, and it is not easy to peel off from a glass substrate or the like. Furthermore, since the single-sided protective polarizing film with an adhesive layer of the present invention has the aforementioned adhesive layer, it can effectively suppress the generation of nano-slits even without providing a coating layer.

Form used to implement the invention The single-sided protective polarizing film with an adhesive layer of the present invention will be described below with reference to FIG. 1 . The single-sided protective polarizing film 11 with an 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 the adhesive layer of the present invention. As shown in FIG. 1 , the single-sided protective polarizing film 10 only has the protective film 2 on one side of the polarizer 1 . The polarizer 1 and the protective film 2 are laminated via an adhesive layer 3 (other intermediary layers such as an adhesive layer and a primer layer). In addition, although not shown in the figure, the single-sided protective polarizing film 10 may be provided with an easy-adhesive layer on the protective film 2 or subject it to an activation treatment, and the easy-adhesive layer and the adhesive layer may be laminated. In addition, although not shown in the figure, a plurality of protective films 2 may be provided. Multiple protective films 2 can be laminated via an adhesive layer 3 (other intermediary layers such as an adhesive layer and a primer layer).

As shown in FIG. 1 , the adhesive layer 4 in the single-sided protective polarizing film 11 with an adhesive layer of the present invention can be disposed on the polarizer 1 side of the single-sided protective polarizing film 10 . Furthermore, although not shown in the figure, 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 Japanese Patent No. 6077618 can be applied. In addition, a separator 5 can be provided on the adhesive layer 4 of the single-sided protective polarizing film 11 with an adhesive layer of the present invention, and a surface protection film 6 can be provided on the opposite side. In the single-sided protective polarizing film 11 with an adhesive layer in FIG. 1 , the separation member 5 and the surface protective film 6 are both provided. The single-sided protective polarizing film 11 with at least the adhesive layer of the separator 5 (and the one with the surface protective film 6) can be used in the form of a roll, which is advantageous for use in applications where the membrane is released from the roll as described later. The single-sided protective polarizing film 11 with an adhesive layer that is output and transported by the separator 5 is attached to the surface of the image display panel through the adhesive layer 4 (hereinafter also referred to as the "roll to panel method"). The representative has Japanese Patent No. 4406043 specification). The single-sided protective polarizing film with an adhesive layer shown in Figure 1 is suitable for use from the viewpoint of suppressing warpage of the display panel after lamination and suppressing the occurrence of nano-slits.

Figure 2 is a conceptual diagram comparing the nano slit a and the penetrating crack b generated in the polarizer. FIG. 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 nanoslit a is generated due to mechanical impact, and the nanoslit a locally generated in the direction of the absorption axis of the polarizer 1 cannot be confirmed at the time of generation, but can be detected in a thermal environment (such as 80°C or 60°C). , 90%RH) is confirmed by expanding in the width direction. On the other hand, it is generally believed that the nanoslit a does not have the ductility to extend along the absorption axis direction of the polarizer. In addition, the aforementioned nanoslit a is considered to be generated regardless of the size of the polarizing film. Nanoslit a will be generated alone or adjacent to each other. On the other hand, the penetrating crack b is caused by thermal shock (for example, thermal shock test). Penetrating cracks have ductility extending along the absorption axis direction of the cracked polarizer. When a penetrating crack b occurs, the surrounding stress is released, so penetrating cracks do not form adjacently.

>Polarized parts> In the present invention, from the viewpoint of thinning and suppressing the occurrence of penetrating cracks, the thickness of the polarizer is preferably 12 μm or less, more preferably 10 μm or less, more preferably 8 μm or less, still more preferably 7 μm or less, particularly preferably is below 6μm. On the other hand, the thickness of the polarizer is preferably 1 μm or more. Such thin polarizers have less thickness variation, good visibility, and few dimensional changes, so they have excellent durability against thermal shock.

The polarizer uses polyvinyl alcohol-based resin. Examples of polarizers include hydrophilic polymer films such as polyvinyl alcohol-based films, partially formalized polyvinyl alcohol-based films, and ethylene-vinyl acetate copolymer-based partially saponified films that adsorb iodine or dichroic dyes. Polyene-based oriented films such as polyvinyl alcohol dehydrated products or polyvinyl chloride dehydrochloric acid-treated products, which are uniaxially stretched. Among them, a polarizer composed of a polyvinyl alcohol-based film and a dichroic material such as iodine is suitable.

A polarizing element in which a polyvinyl alcohol-based film is dyed with iodine and uniaxially stretched can be produced by, for example, dipping polyvinyl alcohol in an iodine aqueous solution, dyeing it, and stretching it to 3 to 7 times its original length. It may also contain boric acid, zinc sulfate, zinc chloride, etc. as needed, and may also be immersed in an aqueous solution of potassium iodide, etc. Furthermore, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed before dyeing. By washing the polyvinyl alcohol-based film with water, the dirt and anti-caking agent on the surface of the polyvinyl alcohol-based film can be washed away. In addition, by swelling the polyvinyl alcohol-based film, it can also prevent uneven dyeing and other unevenness. The extension can be performed after dyeing with iodine, or it can be dyed and extended at the same time, or it can be dyed with iodine after stretching. It can also be extended in an aqueous solution of boric acid or potassium iodide or in a water bath.

From the viewpoint of extension stability or optical durability, it is preferable that the polarizer contains boric acid. Furthermore, from the viewpoint of suppressing the occurrence and expansion of penetrating cracks and nano-slits, the boric acid content contained in the polarizer is preferably 25% by weight or less, more preferably 20% by weight or less, based on the total amount of the polarizer. The content is 18% by weight or less, more preferably 16% by weight or less. When the boric acid content of the polarizer is greater than 25% by weight, even if the thickness of the polarizer is thinned (for example, the thickness is less than 12 μm), the shrinkage stress of the polarizer will still become high and penetrating cracks will easily occur, which is not ideal. On the other hand, from the viewpoint of the extension stability and optical durability of the polarizer, the boric acid content is preferably 10% by weight or more, more preferably 12% by weight or more, based on the total amount of the polarizer.

Representative examples of thin polarizers include: Japanese Patent No. 4751486 Specification, Japanese Patent No. 4751481 Specification, Japanese Patent No. 4815544 Specification, Japanese Patent No. 5048120 Specification, Japanese Patent No. 5587517 Specification, International Publication No. 2014/077599 Manual, The thin polarizer described in International Publication No. 2014/077636, etc., or the thin polarizer produced by the manufacturing method described therein.

The aforementioned polarizing element is preferably configured so that the optical characteristics represented by the single transmittance T and polarization degree P satisfy the conditions of the following formula: P>-(10 ^0.929T-42.4 -1)×100 (but, T>42.3), Or P≧99.9 (only, T≧42.3). In short, a polarizing element configured to satisfy the above conditions has the performance required for a liquid crystal television display using a large display element. Specifically, the contrast ratio is 1000:1 or more and the maximum brightness is 500cd/m2 ^or more. For other uses, for example, it can be attached to the viewing side of an organic EL display device.

On the other hand, polarizers configured to satisfy the above conditions are compatible with thin (for example, thickness 12 μm or less) configurations because the polymers (for example, polyvinyl alcohol-based molecules) that constitute them exhibit high degree of orientation. The tensile fracture stress in the direction perpendicular to the absorption axis is significantly reduced. As a result, for example, when the polarizing film is subjected to a mechanical impact greater than the tensile fracture stress during the manufacturing process, nanoslits are likely to be generated in the direction of the absorption axis of the polarizing element. Therefore, the present invention is particularly suitable for using a single-sided protective polarizing film with the polarizer (or a single-sided protective polarizing film with an adhesive layer attached thereto).

In a manufacturing method including a step of stretching in a laminated state and a dyeing step, from the viewpoint of being able to stretch at high magnification and improving the polarization performance, the aforementioned thin polarizer has been manufactured in Japanese Patent No. 4751486, Japanese Patent No. 4751481 It is preferably prepared by a method including a step of extending in a boric acid aqueous solution as described in the specification of Japanese Patent No. 4815544, and particularly as described in the specification of Japanese Patent No. 4751481 and Japanese Patent No. 4815544. It is preferably prepared by a method including a step of auxiliary stretching in the air before stretching in a boric acid aqueous solution. These thin polarizers can be obtained by a manufacturing method including the steps of stretching a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a stretching resin base material in a laminated state; Dyeing steps. According to this production method, even if the PVA-based resin layer is very thin, it can be stretched without problems such as breakage due to stretching since it is supported by the resin base material for stretching.

>Protective film> The material constituting the protective film is preferably one that is excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and the like. Examples include: polyester polymers such as polyethylene terephthalate or polyethylene naphthalate; cellulose polymers such as diacetyl cellulose or triacetyl cellulose; polymethylmethacrylate Acrylic polymers such as ester; styrenic polymers such as polystyrene and acrylonitrile-styrene copolymer (AS resin); polycarbonate polymers, etc. In addition, the following polymers can also be cited as examples of polymers that form the above-mentioned protective film: polyethylene, polypropylene, polyolefins having a ring system or even a norbornene structure, and polyolefin-based polymers such as ethylene-propylene copolymers. , Vinyl chloride polymers, amide polymers such as nylon or aromatic polyamide, amide imine polymers, polyether polymers, polyether ether ketone polymers, polyethylene Phenyl sulfide polymers, vinyl alcohol polymers, chlorinated vinylene polymers, vinyl butyral polymers, aryl ester polymers, polyoxymethylene polymers, epoxy polymers or the above polymers blends, etc.

In addition, the protective film may contain one or more arbitrary appropriate additives. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, colorants, and the like. The thermoplastic resin content in the protective film is preferably 50 to 100% by weight, preferably 50 to 99% by weight, more preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. When the content of the thermoplastic resin in the protective film is less than 50% by weight, there is a risk that the high transparency originally possessed by the thermoplastic resin may not be fully demonstrated.

As the aforementioned protective film, a retardation film, a brightness enhancement film, a diffusion film, etc. can also be used. Examples of the retardation film include those having a front surface retardation of 40 nm or more and/or a thickness direction retardation of 80 nm or more. The frontal phase difference is usually controlled in the range of 40~200nm, and the thickness direction phase difference is usually controlled in the range of 80~300nm. When a retardation film is used as a protective film, the retardation film can also function as a polarizer protective film, so the thickness can be reduced.

Examples of the retardation film include birefringent films obtained by uniaxially or biaxially stretching a thermoplastic resin film. The above-mentioned stretching temperature, stretching ratio, etc. can be appropriately set according to the phase difference value, film material and thickness.

The thickness of the protective film can be appropriately determined, but is generally about 1 to 500 μm from the viewpoint of workability, thinness, etc., such as strength and operability. It is particularly suitable to be 1~300μm, preferably 5~200μm, and even more preferably 5~150μm, especially a thin one of 5~80μm.

The surface of the aforementioned protective film that is not connected to the polarizer can be provided with functional layers such as a hard coating layer, an anti-reflection layer, an anti-adhesion layer, a diffusion layer and even an anti-glare layer. In addition, in addition to being provided on the protective film itself, the functional layers such as the hard coat layer, anti-reflective layer, anti-adhesive layer, diffusion layer or anti-glare layer may be provided separately from the protective film.

>Intermediate Layer> The protective film and the polarizing element are laminated via an intermediary layer such as an adhesive layer, an adhesive layer, and a primer layer. At this time, it is expected that the two can be laminated without air gaps through an interposer layer. It is preferable that the protective film and the polarizer are laminated with an adhesive interposed therebetween.

The adhesive layer is formed of an adhesive. The type of adhesive is not particularly limited, and various substances can be used. The adhesive layer is not particularly limited as long as it is optically transparent. The adhesive can be of various forms such as water-based, solvent-based, hot-melt adhesive, active energy ray curable, etc. Water-based adhesive or active energy ray curable type can be used as the adhesive. The adhesive is suitable.

Examples of the water-based adhesive include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex-based adhesives, water-based polyesters, and the like. Water-based adhesives are usually used as adhesives composed of aqueous solutions and usually contain 0.5 to 60% by weight of solid content.

Active energy ray curable adhesive is an adhesive that is cured by active energy rays such as electron rays and ultraviolet rays (radical curing type and cation curing type). For example, it can be used in the form of electron ray curing type or ultraviolet ray curing type. As the active energy ray curable adhesive, for example, a photo radical curable adhesive can be used. When a photoradically curable active energy ray curable adhesive is used as an ultraviolet curable adhesive, the adhesive contains a radically polymerizable compound and a photopolymerization initiator.

The application method of the adhesive can be appropriately selected according to the viscosity or target thickness of the adhesive. Examples of coating methods include: reverse coater, gravure coater (direct, reverse or offset), rod reverse coater, roller coater, die coater, rod coater, rod coater, etc. . In addition, coating methods such as dipping can be used appropriately.

Furthermore, when a water-based adhesive or the like is used for application of the adhesive, it is preferable that the thickness of the final adhesive layer is 30 to 300 nm. The thickness of the aforementioned adhesive layer is more preferably 60~250nm. On the other hand, when using an active energy ray-curable adhesive, it is preferable to set the thickness of the adhesive layer to 0.1 to 200 μm. It is preferably 0.5~50μm, and more preferably 0.5~10μm.

When laminating a polarizer and a protective film, an easy-adhesion layer may be provided between the protective film and the adhesive layer. The easy-adhesion layer can be formed of various resins having, for example, the following skeletons: polyester skeleton, polyether skeleton, polycarbonate skeleton, polyurethane skeleton, polysiloxane series, polyamide skeleton, polyimide skeleton , polyvinyl alcohol skeleton, etc. These polymer resins can be used individually by 1 type, or in combination of 2 or more types. In addition, other additives may be added when forming the easy-adhesion layer. Specifically, stabilizers such as tackifiers, ultraviolet absorbers, antioxidants, heat-resistant stabilizers, etc. can be used.

The easy-adhesive layer is usually provided on the protective film in advance, and the easy-adhesive layer side of the protective film is laminated with the polarizer through an adhesive layer. The easy-adhesive layer can be formed by applying a material for forming the easy-adhesive layer on a protective film using known techniques and drying it. The forming material of the easy-adhesive layer is usually adjusted to a solution that has been diluted to an appropriate concentration, taking into account the thickness after drying, smoothness of application, etc. The thickness of the easy-adhesive layer after drying is preferably 0.01~5 μm, more preferably 0.02~2 μm, and more preferably 0.05~1 μm. In addition, the easy-adhesive layer may be provided with multiple layers. In this case, it is also appropriate to make the total thickness of the easy-adhesive layer fall within the above range.

The adhesive layer is formed of adhesive. Various adhesives can be used as the adhesive, such as rubber-based adhesives, acrylic-based adhesives, polysilicone-based adhesives, urethane-based adhesives, vinyl alkyl ether-based adhesives, and polyvinylpyrrolidine. Ketone adhesives, polyacrylamide adhesives, cellulose adhesives, etc. The adhesive base polymer can be selected according to the type of adhesive mentioned above. Among the above-mentioned adhesives, acrylic adhesives are preferably used because they have good optical transparency, exhibit adhesive properties such as appropriate wettability, cohesiveness, and adhesiveness, and are excellent in weather resistance and heat resistance.

The primer layer (primer layer) is formed to improve the adhesion between the polarizer and the protective film. The material constituting the primer layer is not particularly limited as long as it can exert a certain degree of strong adhesion to both the base film and the polyvinyl alcohol-based resin layer. For example, thermoplastic resins that are excellent in transparency, thermal stability, elongation, etc. can be used. Examples of the thermoplastic resin include acrylic resin, polyolefin resin, polyester resin, polyvinyl alcohol resin, or mixtures thereof.

>Adhesive layer> The adhesive layer of the single-sided protective polarizing film with an adhesive layer of the present invention is formed of an acrylic adhesive containing a (meth)acrylic polymer as a base polymer. Acrylic adhesives have excellent optical transparency, exhibit moderate wettability, cohesiveness, and adhesive properties, and have excellent weather resistance and heat resistance, so they are suitable as materials for forming adhesive layers.

The weight change rate of the adhesive layer calculated from the following formula (1) is 1.1% or more, preferably 1.2% or more, and more preferably 1.3% or more. If the weight change rate is less than 1.1%, the durability and conductive stability of the adhesive layer in high temperature and/or high humidity environments will tend to deteriorate. In addition, from the viewpoint of adjusting the following adhesive forces P ₁ and P ₂ to a target range, the weight change rate is preferably 2.0% or less, and more preferably 1.8% or less. Weight change rate (%) = {(W ₁ -W ₀ )/W ₀ }×100 (1) W ₀ =The weight of the adhesive layer after drying the aforementioned adhesive layer at 23°C for 2 hours W ₁ =The After the aforementioned drying, the weight of the adhesive layer after being placed at 23°C 55%RH for 5 hours and at 60°C 95%RH for 5 hours

In addition, the adhesive force P ₀ of the aforementioned adhesive layer is 10 N/25mm or less under the following conditions, and the adhesive force P ₁ under the following conditions is 1.6 N/25mm or more. If the aforementioned adhesive force P ₀ is greater than 10N/25mm, the initial reworkability will deteriorate. From the above point of view, the adhesive force P ₀ is preferably 8 N/25 mm or less, and is preferably 6 N/25 mm or less. In addition, if the aforementioned adhesive force P ₁ is less than 1.6N/25mm, the adhesive force will easily decrease when exposed to an environment where condensation occurs, and the adhesive layer will easily peel off from a glass substrate or the like. From the above point of view, the aforementioned adhesive force P ₁ is preferably 2N/25mm or more, and more preferably 3N/25mm or more. Adhesion P ₀ : Attach the adhesive layer of the single-sided protective polarizing film with the adhesive layer to the surface of the alkali-free glass, and perform autoclave treatment at 50°C and 0.5atm for 15 minutes. Under the conditions of 23°C, peeling speed of 300mm/min and peeling angle of 90 degrees, the adhesive force when the aforementioned adhesive layer is peeled off the aforementioned alkali-free glass surface. Adhesion force P ₁ : The single-sided protective polarizing film with the aforementioned adhesive layer is peeled off. The adhesive layer is attached to the surface of the alkali-free glass, and is subjected to autoclave treatment at 50°C and 0.5atm for 15 minutes to prepare a laminated body. The laminated body is immersed in water at 23°C for 2 hours, and the aforementioned laminated body is After the body is taken out of the water, the adhesive force when the aforementioned adhesive layer is peeled off the surface of the aforementioned alkali-free glass under the conditions of peeling temperature 23°C, peeling speed 300mm/min and peeling angle 90 degrees

Furthermore, from the above point of view, the adhesive force P ₂ of the adhesive layer under the following conditions is preferably 0.8N/25mm or more, and more preferably 1.0N/25mm or more. Adhesion P ₂ : The adhesive layer of the single-sided protective polarizing film with the adhesive layer is attached to the surface of the alkali-free glass, and is subjected to autoclave treatment at 50°C and 0.5 atm for 15 minutes to prepare a laminate. , the laminated body was immersed in water at 23°C for 5 hours, and after the laminated body was taken out of the water, the adhesive layer was removed from the adhesive layer under the conditions of peeling temperature of 23°C, peeling speed of 300 mm/min and peeling angle of 90 degrees. Adhesion of alkali-free glass surface during peeling

The (meth)acrylic polymer may have a monomer unit of (meth)acrylic acid alkyl ester as its main skeleton. In addition, (meth)acrylate refers to acrylate and/or methacrylate, and (meth) in the present invention is also synonymous.

The alkyl (meth)acrylate constituting the main skeleton of the (meth)acrylic polymer has a carbon number of about 1 to 18 in the alkyl group. Specific examples of the alkyl (meth)acrylate are as follows: Methyl methacrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, Amyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, (meth)acrylic acid Nonyl ester, isononyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, etc., and these can be used alone or in combination.

In order to obtain an adhesive layer that has the aforementioned weight change rate and the aforementioned adhesive force P ₀ to P ₂ and can suppress the occurrence of nano-slits, the (meth)acrylic polymer preferably contains the following as monomer units: 50% by weight The alkyl (meth)acrylate (A) above (more preferably 60% by weight or more, more preferably 70% by weight or more, still more preferably 80% by weight or more), and the glass transition temperature of its homopolymer Lower than 0℃ (more preferably below -20℃, more preferably below -40℃); and 0.1~20% by weight (more preferably 1~15% by weight, more preferably 2.5~10% by weight, and then More preferably, it is a high Tg monomer (B) (more than 4% by weight and less than 10% by weight), which is selected from the group consisting of (meth)acrylic acid alkyl ester (b1) and (meth)acrylyl group-containing monomers. (b2) At least one of the groups constituted by the glass transition temperature of the homopolymer of the alkyl (meth)acrylate (b1) is 0°C or higher (more preferably 20°C or higher, and more preferably 40°C) ℃ or above), the glass transition temperature of the aforementioned homopolymer containing (meth)acrylyl group monomer (b2) is 0 ℃ or above (more preferably 20 ℃ or above, and more preferably 40 ℃ or above) and has a heterocyclic ring . In addition, when the above-mentioned (meth)acrylic acid alkyl ester (b1) and the above-mentioned (meth)acryl group-containing monomer (b2) are used together, it is the total weight %.

Examples of the alkyl (meth)acrylate (A) include ethyl acrylate (Tg: -24°C), n-butyl acrylate (Tg: -50°C), and n-pentyl methacrylate (Tg: -5°C). ), n-hexyl acrylate (Tg: -57℃), n-hexyl methacrylate (Tg: -5℃), n-octyl acrylate (Tg: -65℃), n-octyl methacrylate (Tg: -20℃ ), n-nonyl acrylate (Tg: -58℃), n-lauryl acrylate (Tg: -3℃), n-lauryl methacrylate (Tg: -65℃), n-tetradecyl methacrylate (Tg: -72℃), isopropyl acrylate (Tg: -3℃), isobutyl acrylate (Tg: -40℃), isooctyl acrylate (Tg: -58℃), isooctyl methacrylate (Tg: -45℃), 2-ethylhexyl acrylate (Tg: -70℃), 2-ethylhexyl methacrylate (Tg: -10℃), etc. These may be used individually or in combination. Among them, at least one selected from the group consisting of ethyl acrylate, n-butyl acrylate, n-pentyl methacrylate, n-hexyl acrylate, and 2-ethylhexyl acrylate is preferably used, and n-acrylate is more preferably used. butyl ester. In addition, the Tg (glass transition temperature) in each parentheses mentioned above is the Tg of the homopolymer obtained by polymerizing each monomer. The same applies to the following records.

Examples of the alkyl (meth)acrylate (b1) include methyl acrylate (Tg: 8°C), methyl methacrylate (Tg: 105°C), ethyl methacrylate (Tg: 65°C), and acrylic acid. n-propyl ester (Tg: 3℃), n-propyl methacrylate (Tg: 35℃), n-amyl acrylate (Tg: 22℃), n-tetradecanyl acrylate (Tg: 24℃), n-hexadecane acrylate Ester (Tg: 35℃), n-octadecyl methacrylate (Tg: 15℃), n-octadecyl acrylate (Tg: 30℃) and n-octadecyl methacrylate (Tg: 38℃), etc. (methacrylate base) linear alkyl acrylate; tertiary butyl acrylate (Tg: 43℃), tertiary butyl methacrylate (Tg: 48℃), isopropyl methacrylate (Tg: 81℃) and methyl Branched alkyl (meth)acrylates such as isobutyl acrylate (Tg: 48℃); cyclohexyl acrylate (Tg: 19℃), cyclohexyl methacrylate (Tg: 65℃), isocamphenyl acrylate (Tg: 94°C) and (meth)acrylic acid cyclic alkyl esters such as isocamphenyl methacrylate (Tg: 180°C). These may be used individually or in combination. Among these, it is preferable to use at least one selected from the group consisting of methyl acrylate, methyl methacrylate, ethyl methacrylate, isocamphenyl acrylate, and isocamphenyl methacrylate, and more preferably, one selected from the group consisting of At least one of methyl acrylate, methyl methacrylate and isocamphenyl acrylate.

The aforementioned (meth)acrylyl group-containing monomer (b2) has a heterocyclic ring. Although the heterocyclic ring is not particularly limited, examples thereof include an aziridine ring, an azole ring, a pyrrolidine ring, a piperidine ring, and a piperidine ring. aliphatic heterocycles such as ring and mofulin ring; pyrrole ring, imidazole ring, pyrazole ring, azole ring, iso Azole ring, thiazole ring, isothiazole ring, pyridine ring, pyrimidine ring, ring and pyridine Rings and other aromatic heterocycles. The aforementioned heterocyclic ring may be directly bonded to the (meth)acrylyl group, or may be bonded to the (meth)acrylyl group through a linking group. Among these, an aliphatic heterocyclic ring is preferred, and a mofelin ring is more preferred. Examples of the (meth)acrylyl group-containing monomer (b2) include N-acrylylmorphine (Tg: 145°C). These may be used individually or in combination. Among these, N-acrylomorphine is particularly preferred.

In order to improve adhesiveness, thermal conductivity, etc., one or more types of various monomers may be introduced into the (meth)acrylic polymer by copolymerization. Specific examples of the comonomer (except for the aforementioned (meth)acrylyl group-containing monomer (b2)) include carboxyl group-containing monomers, hydroxyl-containing monomers, nitrogen-containing monomers and aromatic group-containing monomers. Body etc.

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 individually or in combination.

Examples of hydroxyl-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate. , 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate and (4-hydroxymethylcyclohexyl)-methacrylate, etc. These may be used individually or in combination.

Examples of the nitrogen-containing monomer include vinyl-based monomers having a lactam ring (such as vinylpyrrolidone-based monomers such as N-vinylpyrrolidone and methylvinylpyrrolidone; and vinyl-based monomers having a β-lactam ring). Vinyl lactam monomers of lactam rings such as amide ring, δ-lactam ring and ε-lactam ring, etc.); maleimide, N-cyclohexylmaleimide, Maleimide monomers such as N-phenylmaleimide; (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl( Meth)acrylamide, N-hexyl(meth)acrylamide, N-methyl(meth)acrylamide, N-butyl(meth)acrylamide, N-butyl(methyl) (N-substituted) amide monomers such as acrylamide, N-methylol (meth)acrylamide, N-methylolpropane (meth)acrylamide, etc.; (meth)acrylic acid ethyl amine , (meth)acrylic acid amine propyl ester, (meth)acrylic acid N,N-dimethylamine ethyl ester, (meth)acrylic acid tertiary butylamine ethyl ester, 3-(3-pyridyl)propyl ( (meth)acrylic aminoalkyl monomers such as meth)acrylates; N-(meth)acryloxymethylenesuccinimide, N-(meth)acryl-6-oxy Succinimide monomers such as hexamethylene succinimide and N-(meth)acryl-8-oxyoctamethylene succinimide; cyanogens such as acrylonitrile and methacrylonitrile (meth)acrylate monomer; vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piper , Vinylpyr , vinylpyrrole, vinylimidazole, vinyl Azoles, vinylmorphine, N-vinylcarboxylic acid amide, etc. These may be used individually or in combination.

Examples of the aromatic group-containing monomer include benzyl (meth)acrylate, phenyl (meth)acrylate, and phenoxyethyl (meth)acrylate. These may be used individually or in combination.

In addition to the above-mentioned monomers, there are also acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adduct of acrylic acid; styrene sulfonic acid or allyl sulfonic acid, 2-(methyl )Sulfonic acid group-containing monomers such as acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, (meth)sulfopropyl acrylate or (meth)acryloxynaphthalenesulfonic acid Phosphate group-containing monomers such as 2-hydroxyethylacrylyl phosphate, etc. These may be used individually or in combination.

In addition, vinyl-based monomers such as vinyl acetate, vinyl propionate, styrene, α-methylstyrene, and N-vinylcaprolactam; and epoxypropyl (meth)acrylate, etc. can also be used. Epoxy acrylic monomer; polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxy (meth)acrylate Diol acrylate monomers such as polypropylene glycol ester; acrylic acids such as tetrahydrofurfuryl (meth)acrylate, fluoro(meth)acrylate, polysiloxy (meth)acrylate and 2-methoxyethyl acrylate Ester monomers, etc. These may be used individually or in combination.

From the viewpoint of improving the cohesive force of the (meth)acrylic polymer to more effectively suppress the generation of the nano-slits, it is preferable to use a monomer selected from the group consisting of the aforementioned carboxyl group-containing monomer, the aforementioned hydroxyl-containing monomer, and the aforementioned nitrogen-containing monomer. The monomer and at least one polar monomer among the aforementioned aromatic group-containing monomers (except for the aforementioned (meth)acrylyl group-containing monomer (b2)) are introduced into the aforementioned (meth)acrylic polymer through copolymerization. , it is more preferable to introduce the aforementioned carboxyl group-containing monomer, the aforementioned hydroxyl-containing monomer and the aforementioned nitrogen-containing monomer into the aforementioned (meth)acrylic polymer through copolymerization. The aforementioned carboxyl group-containing monomer is preferably (meth)acrylic acid. The aforementioned hydroxyl-containing monomer is preferably at least one selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. The aforementioned nitrogen-containing monomer is preferably a vinyl-based monomer having a lactam ring, more preferably the aforementioned vinylpyrrolidone-based monomer, and more preferably N-vinylpyrrolidone. By introducing the aforementioned nitrogen-containing monomer into the aforementioned (meth)acrylic polymer through copolymerization, the generation of nano-slits can be more effectively suppressed, and the durability of the adhesive layer at high temperatures and/or high humidity can be improved at the same time. properties (peeling resistance). The aforementioned aromatic group-containing monomer is preferably phenoxyethyl (meth)acrylate.

The (meth)acrylic polymer preferably contains 0.01 to 3% by weight of the aforementioned carboxyl group-containing monomer as a monomer unit, more preferably 0.05 to 1% by weight, and still more preferably 0.1 to 0.5% by weight.

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

The (meth)acrylic polymer preferably contains 0.1 to 5% by weight of the aforementioned 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 (meth)acrylic polymer preferably contains 1 to 20% by weight of the aromatic group-containing monomer as a monomer unit, more preferably 1 to 18% by weight, and still more preferably 1 to 15% by weight.

The weight average molecular weight of the (meth)acrylic polymer is not particularly limited, but from the viewpoint of the coating properties of the adhesive, it is preferably 1.5 million or less, more preferably 1.4 million or less, and more preferably 1.3 million or less. In addition, from the viewpoint of adhesive properties, weather resistance, heat resistance, etc., the weight average molecular weight is generally 800,000 or more, and preferably 1,000,000 or more.

The (meth)acrylic polymer can be produced by a known method, 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 and peroxide-based initiators can be used. The reaction temperature is usually around 50~80°C, and the reaction time is set to 1~8 hours. In addition, among the above-mentioned production methods, the solution polymerization method is preferred, and the solvent for the (meth)acrylic polymer is generally ethyl acetate, toluene, etc.

A cross-linking agent may be blended into the aforementioned adhesive. The cross-linking agent can improve the adhesion and durability, improve reliability under high temperatures and maintain the shape of the adhesive itself. As the cross-linking agent, isocyanate-based, epoxy-based, peroxide-based, metal chelate-based, Zozoline series, etc. These cross-linking agents may be used alone or in combination of two or more types.

An isocyanate compound can be used as the isocyanate cross-linking agent. Examples of isocyanate compounds include toluene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, stubble diisocyanate, diphenylmethane diisocyanate, hydrogenated Isocyanate monomers such as diphenylmethane diisocyanate and adducts obtained by adding these isocyanate monomers to trimethylolpropane, etc. are isocyanate compounds; trimeric isocyanate compounds, biuret-type compounds, and well-known Urethane prepolymer type isocyanate, etc., formed by the addition reaction of polyether polyol or polyester polyol, acrylic polyol, polybutadiene polyol and polyisoprene polyol.

The above-mentioned isocyanate-based cross-linking agent can be used alone, or two or more types can be mixed and used, and the overall content should preferably contain 0.01 to 2 parts by weight of the above-mentioned isocyanate-based cross-linking agent relative to 100 parts by weight of the base polymer, and Preferably, it contains 0.02~2 parts by weight, and more preferably it contains 0.05~1.5 parts by weight. A cross-linking agent can be suitably contained in consideration of cohesion and prevention of peeling during a durability test.

Various peroxides can be used as the peroxide cross-linking agent. Examples of peroxides include di(2-ethylhexyl)peroxydicarbonate, di(4-tertiary butylcyclohexyl)peroxydicarbonate, di-secondary butylperoxydicarbonate, and tertiary butylperoxydicarbonate. 1, 1,3,3-tetramethylbutylperoxyisobutyrate, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, bis(4-methylbenzyl acyl) peroxide, benzyl peroxide, tertiary butyl peroxyisobutyrate, etc. Among them, it is particularly suitable to use bis(4-tertiary butylcyclohexyl)peroxydicarbonate, dilauryl peroxide, and benzoyl peroxide, which have excellent cross-linking reaction efficiency.

One type of the aforementioned peroxide can be used alone, or two or more types can be mixed and used. However, the overall content of the aforementioned peroxide is 0.01 to 2 parts by weight relative to 100 parts by weight of the base polymer, and preferably 0.04 to 1.5 parts by weight. parts by weight, preferably 0.05~1 parts by weight. It can be appropriately selected within this range to adjust processability, heavy workability, cross-linking stability, peelability, etc.

In order to obtain an adhesive layer with the aforementioned adhesive force P ₀ ~P ₂ , the aforementioned adhesive should preferably contain a silane coupling agent. As the silane coupling agent, one having any appropriate functional group can be used. Examples of the functional group include a vinyl group, an epoxy group, an amino group, an acid anhydride group, a mercapto group, a (meth)acryloxy group, an acetyl acetyl group, an isocyanate group, a styrene group, a polysulfide group, and the like. Specific examples include vinyl-containing silane coupling agents such as vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, and vinyltributoxysilane; γ-ring Oxypropoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4- Silane coupling agents containing epoxy groups such as epoxycyclohexyl)ethyltrimethoxysilane; γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethyl Oxysilane, N-(2-aminoethyl)3-aminopropylmethyldimethoxysilane, γ-triethoxysilyl-N-(1,3-dimethylbutylene)propylamine, Silane coupling agents containing amine groups such as N-phenyl-γ-aminopropyltrimethoxysilane; silane coupling agents containing acid anhydride groups such as 3-trimethoxysilylpropylsuccinic anhydride; γ-mercaptopropylmethyldi Silane coupling agents containing mercapto groups such as methoxysilane; silane coupling agents containing styrene groups such as p-styrenetrimethoxysilane; γ-acryloxypropyltrimethoxysilane, γ-methacryloxysilane Silane coupling agents containing (meth)acrylyl groups such as propyltriethoxysilane; silane coupling agents containing isocyanate groups such as 3-isocyanatepropyltriethoxysilane; bis(triethoxysilylpropyl) ) Tetrasulfide and other polysulfide-based silane coupling agents, etc. These may be used individually or in combination. Among these, it is preferable to use an adhesive layer selected from the group consisting of epoxy group, isocyanate group, mercapto group, The silane coupling agent is a silane coupling agent having at least one functional group from the group consisting of an acid anhydride group and an amine group, and a silane coupling agent having an epoxy group, an isocyanate group, a mercapto group or an acid anhydride group is more preferred.

Furthermore, an oligomer-type silane coupling agent can also be used from the viewpoint of producing an adhesive layer that is not easily peeled off from a glass substrate or the like even when exposed to an environment where condensation occurs. Here, the so-called oligomer type refers to a polymer whose monomers are more than dimers and less than about 100 monomers, and the weight average molecular weight of the oligomer type silane coupling agent is preferably about 300 to 30,000.

Examples of the oligomer-type silane coupling agent include epoxy group-containing silane coupling agent, thiol group-containing silane coupling agent, isocyanate group-containing silane coupling agent, etc., and are preferably thiol group-containing silane coupling agent and isocyanate group-containing silane coupling agent. Silane coupling agent. These may be used individually or in combination.

The epoxy equivalent of the aforementioned silane coupling agent containing epoxy groups is preferably 250~600g/mol from the perspective of the durability of the adhesive layer in high temperature and/or high humidity environments, and is preferably 250~500g/mol, 280 ~400g/mol is better.

The aforementioned epoxy group-containing silane coupling agent preferably has two or more alkoxysilyl groups in the molecule. In addition, the amount of alkoxy groups in the aforementioned epoxy group-containing silane coupling agent in the silane coupling agent is preferably 10 to 60% by weight, and preferably 20 to 50% by weight, and more preferably 20 to 40% by weight. In addition, the aforementioned epoxy group-containing silane coupling agent has one or more epoxy groups in the molecule, thereby making it possible to obtain an adhesive that is not easily peeled off from a glass substrate or the like even if it is exposed to an environment where condensation occurs. From the perspective of the agent layer, it is preferable to have one epoxy group in the molecule. In addition, the epoxy group-containing silane coupling agent preferably has an aromatic ring in the molecule from the aforementioned viewpoint.

Examples of oligomer-type epoxy group-containing silane coupling agents having two or more alkoxysilyl groups in the molecule include X-12-981S, X-12-1231, and X-41- manufactured by Shin-Etsu Chemical Industry Co., Ltd. 1059A, X-41-1056, etc.

From the perspective of the durability of the adhesive layer in high temperature and/or high humidity environments, the thiol equivalent of the aforementioned silane coupling agent containing thiol groups is preferably 1000g/mol or less, and is preferably 800g/mol or less, and is preferably 700g/mol. below, more preferably below 500g/mol. In addition, the lower limit of the mercapto group equivalent is not particularly limited, but is preferably 200 g/mol or more.

The aforementioned thiol group-containing silane coupling agent preferably has two or more alkoxysilyl groups in the molecule. In addition, the amount of alkoxy groups in the aforementioned thiol-containing silane coupling agent in the silane coupling agent is preferably 10 to 60 wt%, more preferably 20 to 50 wt%, and more preferably 20 to 40 wt%.

Examples of oligomer-type thiol group-containing silane coupling agents having two or more alkoxysilyl groups in the molecule include X-41-1805, X-41-1810, and X-41-1818 manufactured by Shin-Etsu Chemical Industry Co., Ltd. X-12-1156 etc.

From the perspective of the durability of the adhesive layer in high temperature and/or high humidity environments, the isocyanate equivalent of the aforementioned isocyanate group-containing silane coupling agent is preferably 250~600g/mol, and preferably 250~500g/mol, 280~400g /mol is better.

The aforementioned isocyanate group-containing silane coupling agent preferably has two or more alkoxysilyl groups in the molecule. In addition, the amount of alkoxy groups in the isocyanate group-containing silane coupling agent in the silane coupling agent is preferably 10 to 60% by weight, more preferably 20 to 50% by weight, and more preferably 20 to 40% by weight.

Examples of oligomer-type isocyanate group-containing silane coupling agents having two or more alkoxysilyl groups in the molecule include X-40-9318 and X-12-1159L manufactured by Shin-Etsu Chemical Industry Co., Ltd.

From the perspective of obtaining an adhesive layer with the aforementioned adhesive force P ₀ ~P ₂ , the overall content of the silane coupling agent is preferably 0.05 to 5 parts by weight relative to 100 parts by weight of the base polymer, and is preferably 0.1 to 3 parts by weight. More preferably, it is 0.2~2 parts by weight.

Moreover, the content of the silane coupling agent (including oligomer type silane coupling agent) having at least one functional group selected from the group consisting of epoxy group, isocyanate group, mercapto group, acid anhydride group and amine group is given by From the viewpoint of producing an adhesive layer having the aforementioned adhesive strength P ₀ to P ₂ , the amount is preferably 0.01 to 3 parts by weight, more preferably 0.1 to 2 parts by weight, and 0.1 to 1 part by weight based on 100 parts by weight of the base polymer. The portion is even better.

Moreover, from the perspective of improving the heavy-duty properties, the aforementioned adhesive should contain a heavy-duty enhancer. The aforementioned heavy industry lifting agent is a chemical substance that has a polar group and is prone to interaction at the glass interface and segregation at the glass interface. Examples of the heavy industry lifting agent include glycols having an alkyloxy group such as EO and PO, oligomers having a perfluoroalkyl group, and polyether compounds having a reactive silicon group. As the polyether compound, for example, those disclosed in Japanese Patent Application Laid-Open No. 2010-275522 can be used.

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

The content of the heavy industry lifting agent is preferably 0.001 parts by weight or more relative to 100 parts by weight of the base polymer, more preferably 0.01 parts by weight or more, and more preferably 0.1 parts by weight or more, and is preferably less than 10 parts by weight, and more preferably 5 parts by weight. Parts by weight or less, more preferably 2 parts by weight or less, still more preferably 1 part by weight or less. If the content of the heavy-duty enhancer is less than 0.001 parts by weight, it will be difficult to improve the heavy-duty properties of the adhesive layer. If it is greater than 10 parts by weight, the adhesive properties of the adhesive layer will tend to decrease.

Furthermore, the aforementioned adhesive preferably contains an antistatic agent. When manufacturing a liquid crystal display device, 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 single-sided protective polarizing film with an adhesive layer, and the release film is peeled off. Mold films can generate static electricity. In addition, when laminating the single-sided protective polarizing film with the adhesive layer to the liquid crystal panel, if a lamination error occurs, the polarizing film must be peeled off. However, static electricity will be generated when peeling off the polarizing film. The generated static electricity will affect the orientation of the liquid crystal inside the liquid crystal display device and cause undesirable conditions. In addition, display unevenness caused by static electricity sometimes occurs when the liquid crystal display device is used. By adding an antistatic agent to the adhesive, the adhesive layer of the single-sided protective polarizing film attached to the adhesive layer can be endowed with antistatic properties, thereby preventing such adverse situations.

The antistatic agent is not particularly limited, and examples thereof include ionic compounds such as onium-anion salts and alkali metal salts. We believe that if ionic compounds are added, the ionic compounds will overflow from the surface of the adhesive layer, thus effectively exhibiting antistatic properties. On the other hand, when an ionic compound comes into contact with a polarizer, optical properties such as polarization degree may be reduced. In particular, alkali metal salts are preferably used from the viewpoint of suppressing the aforementioned decrease in optical characteristics.

As the alkali metal salt, an organic salt or an inorganic salt of an alkali metal can be used. One type of alkali metal salt may be used alone, or multiple types may be used in combination.

Examples of alkali metal ions constituting the cationic part of the alkali metal salt include ions of lithium, sodium, and potassium. Among the alkali metal ions, lithium ions are preferred.

The anionic part of the alkali metal salt can be composed of organic matter or inorganic matter. As the anionic part constituting the organic salt, for example, CH ₃ COO ^- , CF ₃ COO ^- , CH ₃ SO ₃ ^- , CF ₃ SO ₃ ^- , (CF ₃ SO ₂ ) ₂ N ^- , (CF ₃ SO ₂ ) can be used. 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- , etc. In particular, the anionic part containing a fluorine atom is suitable for use because an ionic compound with excellent ion dissociation properties can be obtained. The anionic part constituting the inorganic salt can 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 ^- , etc. The anion part is preferably (CF ₃ SO ₂ ) ₂ N ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- and other (perfluoroalkylsulfonyl)imides, especially (CF ₃ SO ₂ ) ₂ N ^- (trifluoromethanesulfonyl) acyl imine is preferred.

Specific examples of organic salts of alkali metals include 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 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. are preferred, Li(CF ₃ SO ₂ ) ₂ N, Li(C ₂ F ₅ SO ₂ ) ₂ N, Li(C ₄ F ₉ SO ₂ ) ₂ Fluorine-containing lithium imide salts such as N are preferred, and (perfluoroalkylsulfonyl) lithium imide lithium salts are particularly preferred.

In addition, examples of inorganic salts of alkali metals include lithium perchlorate and lithium iodide.

The alkali metal salt content in the adhesive is preferably 0.001 to 5 parts by weight relative to 100 parts by weight of the base polymer. When the alkali metal salt is less than 0.001 parts by weight, the effect of improving antistatic properties may be insufficient. The content of the aforementioned alkali metal salt is preferably 0.01 parts by weight or more, more preferably 0.1 parts by weight or more. On the other hand, if the content of the alkali metal salt exceeds 5 parts by weight, the durability may be insufficient. The content of the aforementioned alkali metal salt is preferably less than 3 parts by weight.

The adhesive layer can be formed by, for example, the following method: apply the aforementioned adhesive on a peeled separation piece, etc., dry and remove the polymerization solvent, etc. to form an adhesive layer and then transfer it to one side. A method of protecting the polarizer side of the polarizing film (the aspect in Figure 1 is a polarizer); or a method of forming an adhesive layer on the polarizer side after applying the aforementioned adhesive and drying to remove the polymerization solvent. In addition, when applying the adhesive, one or more solvents other than the polymerization solvent may be appropriately added.

The thickness of the adhesive layer is not particularly limited, but from the viewpoint of effectively suppressing defects caused by nano-slits and taking into account excellent adhesive properties and reworkability, it is preferably 25 μm or less, more preferably 23 μm or less, and more preferably 20 μm. or less; and, it is preferably 10 μm or more, more preferably 12 μm or more, and still more preferably 15 μm or more.

It is advisable to use polysilicone release lining material for the separation parts that have been peeled off. In the step of applying the adhesive of the present invention on the lining material and drying it to form an adhesive layer, the method for drying the adhesive may be an appropriate and appropriate method depending on the purpose. It is advisable to use the method of overheating and drying the above-mentioned coating film. The heating and drying temperature is preferably 40℃~200℃, more preferably 50℃~180℃, especially 70℃~170℃. By setting the heating temperature within the above range, an adhesive with excellent adhesive properties can be obtained.

The drying time can be appropriately determined. The above-mentioned drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, especially 10 seconds to 5 minutes.

Various methods can be used to form the adhesive layer. Specific examples include roll coating, touch roll coating, gravure coating, reverse coating, roller brushing, spray coating, dip roll coating, rod coating, knife coating, and air blade coating. , curtain coating, lip coating, extrusion coating method using die coater, etc.

When the adhesive layer is exposed, a peeled sheet (separator) can be used to protect the adhesive layer until it is actually used.

Examples of materials constituting the separator include plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films; porous materials such as paper, cloth, and nonwoven fabrics; meshes, and foam sheets , metal foils, laminates thereof, and other appropriate thin sheets, etc., but from the point of view of excellent surface smoothness, plastic films are suitable.

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

The thickness of the aforementioned separation member is usually 5 to 200 μm, preferably about 5 to 100 μm. The aforementioned separation parts may also be subjected to demoulding and antifouling treatment using polysiloxane-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agents, silica powder, etc. as needed, and coating-type, Kneading type, evaporation type and other anti-static treatment. In particular, by appropriately subjecting the surface of the separator to a peeling treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment, the peelability from the adhesive layer can be further improved.

>Surface protection film> A surface protection film can be placed on the single-sided protective polarizing film with an adhesive layer. The surface protection film usually has a base film and an adhesive layer, and protects the polarizer through the adhesive layer.

From the viewpoint of inspectionability and management, the base film of the surface protection film can be selected from a film material that is isotropic or nearly isotropic. Examples of the film material include polyester resins such as polyethylene terephthalate films, cellulose resins, acetate resins, polyether resins, polycarbonate resins, and polyamide resins. A transparent polymer like polyimide resin, polyolefin resin, and acrylic resin. Among them, polyester resin is preferred. The base film can be used in the form of a laminate of one or more film materials, or an extension of the aforementioned film can be used. The thickness of the base film is usually less than 500 μm, preferably 10 to 200 μm.

The adhesive that forms the adhesive layer of the surface protection film can be appropriately selected from (meth)acrylic polymer, polysiloxane polymer, polyester, polyurethane, polyamide, polyether, fluorine or Polymers such as rubber-based polymers are used as adhesives for the base polymer. From the viewpoint of transparency, weather resistance, heat resistance, etc., an acrylic adhesive using an acrylic polymer as the base polymer is suitable. The thickness of the adhesive layer (dry film thickness) can be determined according to the required adhesion. Usually it is about 1~100μm, preferably 5~50μm.

In addition, for the surface protection film, a release treatment layer can also be provided on the opposite side of the base film to the side where the adhesive layer is provided, using low-adhesion materials such as polysiloxane treatment, long-chain alkyl treatment, and fluorine treatment.

>Other optical layers> When actually used, the single-sided protective polarizing film with an adhesive layer of the present invention can be used in the form of an optical film laminated with other optical layers. The optical layer is not particularly limited. For example, one or more layers of reflective plates and semi-transmissive plates, phase difference plates (including 1/2 and 1/4 wavelength plates), viewing angle compensation films, etc. can be used to form liquid crystals. Optical layer of display devices, etc. Particularly preferred is a reflective polarizing film or semi-transmissive polarizing film formed by laminating a reflective plate or a semi-transmissive reflective plate on the single-sided protective polarizing film with an adhesive layer of the present invention, and the single-sided protective polarizing film with an adhesive layer. Elliptically polarizing film or circular polarizing film made by laminating a phase difference plate on the film; wide viewing angle polarizing film made by laminating a viewing angle compensation film on a single side protective polarizing film with an adhesive layer; or a wide viewing angle polarizing film on one side with an adhesive layer. A polarizing film made by laminating a protective polarizing film and a brightness enhancing film.

The optical film formed by laminating the above-mentioned optical layer on a single-sided protective polarizing film with an adhesive layer can also be formed by sequentially laminating layers during the manufacturing process of liquid crystal display devices, etc., as long as the optical film is pre-laminated It has advantages in quality stability and assembly operations, and has the advantage of improving the manufacturing steps of liquid crystal display devices. Appropriate bonding mechanisms such as adhesive layers can be used when laminating. When the above-mentioned single-sided protective polarizing film or other optical layer attached to the adhesive layer is attached, the optical axis thereof can be set to an appropriate arrangement angle according to the desired phase difference characteristics, etc.

The single-sided protective polarizing film or optical film with an adhesive layer of the present invention can be suitably used in the formation of various image display devices such as liquid crystal display devices and organic EL display devices. The liquid crystal display device can be formed according to conventional knowledge. That is, a liquid crystal display device is generally formed by appropriately assembling a liquid crystal cell, a single-sided protective polarizing film or optical film with an adhesive layer, and an optional lighting system and other constituent parts into a drive circuit, etc. However, in this case, Except for the use of the single-sided protective polarizing film or optical film with the adhesive layer of the present invention, there are no special restrictions in the invention, and common knowledge can be followed. Any type of liquid crystal unit can be used, such as IPS type, VA type, etc., but the IPS type is particularly ideal.

It can form a liquid crystal display device in which one or both sides of the liquid crystal unit are equipped with a single-sided protective polarizing film or optical film with an adhesive layer, or a suitable liquid crystal display device in which a backlight or a reflector is used in the lighting system. At this time, the single-sided protective polarizing film or optical film with the adhesive layer of the present invention can be disposed on one side or both sides of the liquid crystal unit. When a single-sided protective polarizing film or optical film with an adhesive layer is provided on both sides, they can be the same or different. In addition, 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 lens array, a lens array sheet, a light diffusion plate, a backlight, etc. can be arranged at appropriate positions 1 layer or more.

>Continuous manufacturing method of image display device> The above-mentioned image display device is preferably manufactured by a continuous manufacturing method (roll-to-face method). The continuous manufacturing method includes the following steps: rolling the roll (roll) of the single-sided protective polarizing film with the adhesive layer attached thereto. The single-sided protective polarizing film with the adhesive layer is released and transported by the separator, and is continuously attached to the surface of the image display panel through the adhesive layer. Since the single-sided protective polarizing film with an adhesive layer of the present invention is a very thin film, if it is cut into sheets (sheet cutting) and then attached to the image display panel one by one (it can also be called "Sheet to panel method"), it will be more difficult to handle when conveying the sheet or laminating it to the display panel, causing the single-sided protective polarizing film (sheet) with the adhesive layer to be damaged during these processes. The risk of huge mechanical impact (such as bending due to adsorption, etc.) is increased. In order to reduce this risk, additional measures such as using a thicker surface protection film with a base film thickness of 50 μm or more are required. However, according to the roll-to-roll method, the single-sided protective polarizing film with the adhesive layer is not cut into sheets (sheet cutting), but a continuous separator is used to stably transport it from the roll to the image display panel And it is directly attached to the image display panel, so there is no need to use a thick surface protection film to significantly reduce the above risks. As a result, by using an adhesive layer controlled so that the film thickness and storage elastic modulus satisfy a predetermined relationship to mitigate mechanical impact, image display panels with effectively suppressed nano-slit generation can be continuously produced at high speed. .

FIG. 5 is a schematic diagram showing an example of a continuous manufacturing system for liquid crystal display devices using the roll-to-roll method. As shown in FIG. 5 , the continuous manufacturing system 100 of a liquid crystal display device includes a conveyance part and the second bonding part 201b. In addition, a roll of a single-sided protective polarizing film with a first adhesive layer (first roll) 20a and a roll of a single-sided protective polarizing film of a second adhesive layer (second roll) 20b It is used when it has an absorption axis in the long side direction and is in the form shown in Figure 1.

(Conveying Department) The conveying part X can convey the liquid crystal display panel P. The conveying part X is composed of a plurality of conveying rollers, suction plates, and the like. The conveying part The arrangement relationship of the conveying direction (for example, the liquid crystal display panel P is rotated 90° horizontally). 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 the liquid crystal display panel P in a cross-polarized relationship.

(First polarizing film supply unit) The first polarizing film supply part 101a continuously supplies the single-sided protective polarizing film (with surface protection film) 21a through the first adhesive layer released from the first roll 20a and conveyed by the separator 5a to the first lamination Section 201a. The first polarizing film supply part 101a has a first delivery part 151a, a first cutting part 152a, a first peeling part 153a, a first winding part 154a, a plurality of conveying roller parts, an accumulation part such as a dancer roller, and the like.

The first release part 151a has a release shaft that can be set with the first roll material 20a, and can release the single-sided protective polarizing film 21a with the strip-shaped adhesive layer provided with the separator 5a from the first roll material 20a.

The first cutting part 152a has a cutting mechanism such as a cutter and a laser device, and an adsorption mechanism. The first cutting part 152a can retain the separator 5a and simultaneously cut the single-sided protective polarizing film 21a of the strip-shaped first adhesive layer to a predetermined length in the width direction. However, a single-sided protective polarizing film 21a (an optical film roll with cut marks) is laminated on the separator 5a and has a strip-shaped adhesive layer with a plurality of cut lines formed at a predetermined length in the width direction as the third protective polarizing film 21a. When the material is rolled 20a, the first cutting part 152a is not required (the same applies to the second cutting part 152b described later).

The first peeling part 153a is a single-sided protective polarizing film 21a that folds the separator 5a inward to peel off the first adhesive layer from the separator 5a. Examples of the first peeling part 153a include a wedge-shaped member, a roller, and the like.

The first winding part 154a can wind up the separator 5a from which the single-sided protective polarizing film 21a has been peeled off the first adhesive layer. The first winding part 154a has a winding shaft, and the winding shaft is provided with a roller for winding the separator 5a.

(1st bonding section) The first laminating part 201a continuously bonds the single-sided protective polarizing film 21a of the first adhesive layer peeled off through the first peeling part 153a through the adhesive layer of the single-sided protective polarizing film 21a of the first adhesive layer. To the liquid crystal display panel P transported via the transport unit X (first laminating step). The first laminating section 81 is configured with a pair of laminating rollers, and at least one of the laminating rollers is configured as a driving roller.

(Second polarizing film supply unit) The second polarizing film supply part 101b continuously supplies the single-sided protective polarizing film (with surface protection film) 21b through the second adhesive layer released from the second roll 20b and conveyed by the separator 5b to the second lamination. Section 201b. The second polarizing film supply part 101b has a second discharge part 151b, a second cutting part 152b, a second peeling part 153b, a second winding part 154b, and an accumulation part such as a plurality of conveying roller parts and dancer rollers. In addition, the second releasing part 151b, the second cutting part 152b, the second peeling part 153b, and the second winding part 154b are respectively connected with the first releasing part 151a, the first cutting part 152a, the first peeling part 153a, The first winding part 154a has the same structure and function.

(Second bonding section) The second laminating part 201b continuously laminated the single-sided protective polarizing film 21b of the second adhesive layer peeled off through the second peeling part 153b through the adhesive layer of the single-sided protective polarizing film 21b of the second adhesive layer. To the liquid crystal display panel P transported via the transport unit X (second laminating step). The second laminating part 201b is configured with a pair of laminating rollers, and at least one of the laminating rollers is configured as a driving roller. Example

The following examples will be given to illustrate the present invention, but the present invention is not limited by the examples shown below. In addition, parts and % in each example are based on weight. Below, all room temperature storage conditions not specified are 23°C and 55%RH.

>Production of single-sided protective polarizing film> (Making polarizers) Corona treatment was applied to one side of the base material of an amorphous isophthalic acid copolymer polyethylene terephthalate (IPA copolymer PET) film (thickness: 100 μm) with a water absorption rate of 0.75% and a Tg of 75°C, and the corona treatment was The treated surface is coated at 25°C with a ratio of 9:1 containing polyvinyl alcohol (degree of polymerization 4200, saponification degree 99.2 mol%) and acetyl-acetyl-modified PVA (degree of polymerization 1200, acetyl-acetyl-modified PVA). An aqueous solution with a quality of 4.6% and a saponification degree of 99.0 mol% or more (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gohsefimer Z200") was dried to form a PVA-based resin layer with a thickness of 11 μm, and a laminate was produced. The obtained laminated body was uniaxially stretched 2.0 times in the longitudinal direction (long side direction) at the free end between rollers with different circumferential speeds in a 120° C. oven (air-assisted stretching treatment). Next, the laminated body was immersed in an insolubilization bath (a boric acid aqueous solution in which 4 parts by weight of boric acid was mixed with 100 parts by weight of water) having a liquid temperature of 30°C for 30 seconds (insolubilization treatment). Next, it was immersed in a dyeing bath with a liquid temperature of 30° C., and the iodine concentration and immersion time were simultaneously adjusted so that the polarizing plate had a predetermined transmittance. In this example, the material was immersed in an iodine aqueous solution in which 0.2 parts by weight of iodine and 1.0 parts by weight of potassium iodide were mixed with 100 parts by weight of water for 60 seconds (dyeing treatment). Next, it was immersed in a crosslinking bath (a boric acid aqueous solution in which 3 parts by weight of potassium iodide and 3 parts by weight of boric acid were mixed with 100 parts by weight of water) with a liquid temperature of 30° C. for 30 seconds (crosslinking treatment). . Thereafter, the laminated body was immersed in a boric acid aqueous solution with a liquid temperature of 70° C. (an aqueous solution obtained by blending 4 parts by weight of boric acid and 5 parts by weight of potassium iodide with respect to 100 parts by weight of water), and at the same time, it was placed between rollers with different peripheral speeds. Perform uniaxial extension in the longitudinal direction (long side direction) so that the total extension ratio reaches 5.5 times (extension in water). Thereafter, the laminated body was immersed in a cleaning bath (an aqueous solution in which 4 parts by weight of potassium iodide was mixed with 100 parts by weight of water) having a liquid temperature of 30° C. (washing treatment). Through the above procedure, an optical film laminate including a polarizer with a thickness of 5 μm and a boric acid content of 16% was obtained. The boric acid content in polarizers is measured by the following method.

For the obtained polarizer, the boric acid peak (665 cm ^-1 ) intensity and the reference peak (2941cm ^-1 ) intensity. The boric acid content index is calculated from the obtained boric acid peak intensity and the reference peak intensity using the following formula, and the boric acid content (% by weight) is determined from the calculated boric acid content index using the following formula. (boric acid content index) = (boric acid peak intensity at 665 cm ^-1 )/(reference peak intensity at 2941 cm ^-1 ) (boric acid content (weight %)) = (boric acid content index) × 5.54 + 4.1

(Making transparent protective film) Transparent protective film: A (meth)acrylic resin film with a thickness of 40 μm and a lactone ring structure is used after corona treatment is applied to the easy-adhesion surface.

(Making adhesives for transparent protective films) 40 parts by weight of N-hydroxyethylacrylamide (HEAA), 60 parts by weight of acrylomorphine (ACMO) and 3 parts by weight of photoinitiator "IRGACURE 819" (manufactured by BASF) were blended to prepare ultraviolet rays Hardening adhesive.

(Preparation of a single-sided protective polarizing film) The above-mentioned ultraviolet curable adhesive is applied on the surface of the polarizer of the above-mentioned optical film laminate so that the thickness of the adhesive layer after curing becomes 0.5 μm, and the above-mentioned transparent protection is attached The film is then irradiated with ultraviolet rays as active energy rays to harden the adhesive. Ultraviolet irradiation uses a metal halide lamp filled with gallium, irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., bulb: V bulb, peak illumination: 1600mW/cm ² , cumulative irradiation dose 1000/mJ/cm ² (wavelength 380~440nm), and the ultraviolet illuminance was measured using the Sola-Check system manufactured by Solatell. Next, the amorphous PET base material is peeled off, and a single-sided protective polarizing film using a thin polarizer is produced. Using the obtained single-sided protective polarizing film, the single transmittance T and polarization degree P of the polarizer were measured by the following method. The single transmittance T of the polarizer was 42.8%, and the polarization degree P of the polarizer was 99.99%. .

The single transmittance T and polarization degree P of the polarizing element of the obtained single-sided protective polarizing film were measured using a spectroscopic transmittance measuring instrument with an integrating sphere (Dot-3c from Murakami Color Technology Research Institute). In addition, the degree of polarization P is the transmittance when two identical single-sided protective polarizing films are overlapped with their transmission axes parallel (parallel transmittance: Tp) and the transmittance when the two transmission axes are orthogonally overlapped ( Vertical transmittance: Tc) is obtained by applying the following formula. Polarization degree P(%)={(Tp-Tc)/(Tp+Tc)} ^1/2 ×100 Each transmittance is based on the complete polarization obtained by Glan-Taylor (Glan-Taylor) polarizer as 100% It is represented by the Y value obtained by calibrating the optical performance of JIS Z8701's 2-degree field of view (C light source).

>Production of double-sided protective polarizing film> A polyvinyl alcohol film with a thickness of 80 μm was dyed in an iodine solution with a concentration of 0.3% by weight at 30° C. for 1 minute and stretched to 3 times between rollers with different speed ratios. Thereafter, the film was immersed in an aqueous solution containing boric acid at a concentration of 4% by weight and potassium iodide at a concentration of 10% by weight at 60° C. for 0.5 minutes while stretching until the total stretching ratio reached 6 times. Next, the polarizer with a thickness of 30 μm was produced by immersing it in an aqueous solution containing potassium iodide at a concentration of 1.5% by weight at 30° C. for 10 seconds, washing, and then drying at 50° C. for 4 minutes. A saponified triacetyl cellulose film with a thickness of 80 μm was bonded to both sides of the polarizer using a polyvinyl alcohol-based adhesive to form a double-sided protective polarizing film.

>Formation of adhesive layer> (Prepare acrylic adhesive 1) Feed the monomer mixture containing 89.78 parts of n-butyl acrylate, 8 parts of methyl methacrylate, 1.5 parts of N-vinylpyrrolidone, 0.2 parts of acrylic acid and 0.48 parts of 4-hydroxybutyl acrylate. It is a four-necked flask equipped with stirring blades, thermometer, nitrogen inlet pipe, and cooler. Then, 0.15 parts of 2,2′-azobisisobutyronitrile as a polymerization initiator was fed together with ethyl acetate relative to 100 parts of the monomer mixture (solid content), and nitrogen gas was introduced while slowly stirring. After nitrogen substitution, the liquid temperature in the flask was maintained at about 60°C, and the polymerization reaction was performed for 7 hours. Thereafter, ethyl acetate was added to the obtained reaction liquid to prepare an acrylic polymer solution with a solid content concentration adjusted to 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 device (HLC-8220GPC) manufactured by Tosoh Co., Ltd. The measurement conditions are as follows. Sample concentration: 0.2 mass% (THF solution) Sample injection volume: 10μl Eluent: THF Flow rate: 0.6ml/min Measuring temperature: 40℃ Column: sample column; TSKguardcolumn SuperHZ-H (1 piece) + TSKgel SuperHZM-H (2 pieces) Reference column; TSKgel SuperH-RC (1 piece) Detector: Differential Refractometer (RI) The weight average molecular weight is calculated in terms of polystyrene.

Per 100 parts of the solid content of the prepared acrylic polymer solution, 1.5 parts of lithium bis(trifluoromethanesulfonyl)imide (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.) and ethylmethyl 1 part of pyrrolidinium-bis(trifluoromethanesulfonyl)imide (manufactured by Tokyo Chemical Industry), 0.25 part of isocyanate cross-linking agent (manufactured by Mitsui Chemicals, trade name "TAKENATE D160N"), peroxide system 0.25 part of cross-linking agent (manufactured by Nippon Oils and Fats Corporation, trade name "NYPER BMT40SV"), 0.1 part of heavy lifting agent (manufactured by KANEKA CORPORATION, trade name "SAT10"), antioxidant (manufactured by BASF Japan, trade name "Irganox 1010") ) 0.3 part of acetyl acetyl group-containing silane coupling agent (manufactured by Soken Chemical Co., Ltd., trade name "A-100") and 0.2 part of an oligomer-type thiol group-containing silane coupling agent (manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "X-41-1810")0.2 part, and prepare acrylic adhesive 1.

(Prepare acrylic adhesive 2~27) The monomer composition when preparing the above-mentioned acrylic adhesive 1 was changed to that shown in Table 1, the polymerization conditions were adjusted, and the type and blending amount of the additives were changed to those shown in Table 1. Otherwise, the same method was followed. A solution of an acrylic polymer was prepared, and acrylic adhesives 2 to 27 were prepared.

(forms adhesive layer) Then, the prepared acrylic adhesives 1 to 27 are evenly coated on the surface of the polyethylene terephthalate film (release film) treated with the polysiloxane release agent using a spray coater. , and dried in an air circulation constant temperature oven at 155°C for 1 minute, and an adhesive layer was formed on the surface of each separation film.

[Table 1]

The compounds in Table 1 are as follows. BA: n-butyl acrylate 4HBA: 4-hydroxybutyl acrylate AA: acrylic NVP: N-vinylpyrrolidone MMA: methyl methacrylate PEA: 2-phenoxyethyl acrylate NYPER BMT40SV: dibenzoyl peroxide D160N: Isocyanate cross-linking agent (manufactured by Mitsui Chemicals Co., Ltd.) D110N: Isocyanate cross-linking agent (manufactured by Mitsui Chemicals Co., Ltd.) C/L: Trimethylolpropane/toluene diisocyanate adduct (manufactured by Tosoh Co., Ltd., trade name "CORONATE L") SAT10: Heavy industry lifting agent (manufactured by Kaneka Co., Ltd.) LiTFSi: lithium bis(trifluoromethanesulfonyl)imide (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.) EMPTFSi: Ethylmethylpyrrolidinium-bis(trifluoromethanesulfonyl)imide (manufactured by Tokyo Chemical Industry) Irganox 1010: Antioxidant (manufactured by BASF Japan) A-100: Silane coupling agent containing acetyl acetyl group (manufactured by Soken Chemical Co., Ltd.) X-41-1810: Oligomer type thiol group-containing silane coupling agent (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) KBM-573: N-phenyl-3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) X-12-1156: Oligomer type thiol group-containing silane coupling agent (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) X-40-9318: Oligomer type isocyanate group-containing silane coupling agent (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) X-88-398: Silane coupling agent containing amine group (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) KBM-6803: N-2-(aminoethyl)-8-aminooctyltrimethoxysilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) X-12-5263H: Silane coupling agent containing amino alkoxy polyfunctional group (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) X-12-981S: Organosilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) X-12-1159L: Oligomer type isocyanate group-containing silane coupling agent (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) X-12-1231: Epoxy group-containing silane coupling agent (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) X-41-1056: Oligomer type epoxy group-containing silane coupling agent (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) X-24-9591F: Oligomer type silane coupling agent containing acid anhydride group (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) TMPS-E: Silane coupling agent containing amine group (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) X-12-967C: 3-Trimethoxysilylpropylsuccinic anhydride (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) KBM-3086: Silane coupling agent containing alkoxy polyfunctional groups (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) KBE-9007N: Isocyanate group-containing silane coupling agent (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) KBM-803: 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) X-12-1056ES: Thiol group-containing silane coupling agent (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) KBM-403: 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd.)

>Examples 1 to 19, Comparative Examples 1 to 11> >Production of single-sided protective polarizing film with adhesive layer> The produced adhesive layers were respectively bonded to the polarizer side of the produced single-sided protective polarizing films, and single-sided protective polarizing films with adhesive layers were produced. >Production of double-sided protective polarizing film with adhesive layer> The produced adhesive layer is respectively bonded to one side of the produced double-sided protective polarizing film, and a double-sided protective polarizing film with an adhesive layer is produced.

The following measurements and evaluations were performed on the adhesive layer obtained above, the single-sided protective polarizing film attached to the adhesive layer, and the double-sided protective polarizing film attached to the adhesive layer. The results are listed in Table 2.

>Suppressing the occurrence of nano-slits: Guitar shrapnel test> Cut the prepared single-sided protective polarizing film with adhesive layer and the double-sided protective polarizing film with adhesive layer into a size of 50 mm × 150 mm (the absorption axis direction is 50 mm) to serve as sample 11. Sample 11 was used by laminating the surface protective film 6 produced by the following method on the protective film 2 side.

(Surface protection film for testing) 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 ethoxydiethylene 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, 150 parts by mass of ethyl acetate, and fed into a stirring blade. , thermometer, nitrogen introduction tube, and cooler, introduce nitrogen while slowly stirring, maintain the liquid temperature in the flask at about 60°C, conduct polymerization reaction for 5 hours, and prepare an acrylic polymer solution ( 40% by mass). The weight average molecular weight of the acrylic polymer is 570,000, and the glass transition temperature (Tg) is -68°C. The acrylic polymer solution (40 mass %) was diluted to 20 mass % with ethyl acetate, and 2 mass parts (solid content 2 mass parts) was added to 500 mass parts (solid content 100 mass parts) of this solution. Tripolyisocyanate of hexamethylene diisocyanate (Coronate HX: C/HX manufactured by Polyurethane Industrial Co., Ltd., Japan), 2 parts by mass (solid content: 0.02 parts by mass) of dilauric acid as a cross-linking catalyst Butyl tin (1 mass % ethyl acetate solution) was mixed and stirred to prepare an acrylic adhesive solution. The aforementioned acrylic adhesive solution was coated on a transparent polyethylene terephthalate (PET) film (polyester film) with a thickness of 38 μm, and heated at 130°C for 1 minute to form an adhesive layer with a thickness of 15 μm. Create a surface protection film.

Next, as shown in the conceptual diagram of Figure 3(A) and the cross-sectional view of Figure 3(B) , the release sheet (separator) is peeled off from the sample 11 and attached to the glass through the exposed adhesive layer 4 On board 20. Next, a guitar spring (manufactured by HISTORY Co., model "HP2H (HARD)") was used to apply a load of 200g on the central part of sample 11 (surface protection film 6 side), and the absorption axis of sample 11 was perpendicular to the polarizer 1 Repeatedly carry out load loading with a distance of 100mm back and forth 50 times in the direction. The aforementioned load loading system is carried out at 1 place. In addition, the aforementioned load application was performed at high speed (7.5m/min). Next, after leaving the sample 11 in an environment of 80° C. for 1 hour, it was confirmed whether there were any light-transmitting cracks in the sample 11 based on the following criteria. ◎：0~10 ○：11~30 pieces ×: 31 or more

Figure 4 is an example of a microscope photograph of the surface of the polarizing film, which is used to confirm the following indicators for light-transmitting cracks (nano slits a) in the guitar shrapnel test of the single-sided protective polarizing film 11 with an adhesive layer. In Figure 4(A), no light-transmitting cracks caused by nanoslit a are confirmed. In addition, Figure 4(B) shows a case where light-transmitting cracks caused by three nano-slits a are produced in the direction of the absorption axis of the polarizer through heating. Figure 4 shows a sample with nano-slits observed under an interference phase contrast microscope. When photographing a sample, a sample without nanoslits is placed under the sample with nanoslits (light source transmission side) in a cross-polarized manner, and observed with transmitted light.

>Measurement of weight change rate> Put 50 mg of the prepared adhesive layer into a sample basket, set it on the device scale, and use a moisture adsorption and desorption measurement device (IGA-Sorp, manufactured by Hiden Corporation) to perform moisture adsorption and desorption. Determination. The measurement conditions are as follows. Substitute the measured W ₀ and W ₁ into the following formula (1) to calculate the weight change rate. Drying (pretreatment to remove moisture from the adhesive layer): (100°C, dry, 1 hour) Program: (23°C, dry, 2 hours) (W ₀ ) → (23°C, 55%RH, 5 hours) →(60℃, 95%RH, 5 hours)(W ₁ )→(23℃, 55%RH, 5 hours) Measurement mode: Continuous weight change rate (%) = {(W ₁ -W ₀ )/W ₀ }×100 (1) W ₀ = Weight of the adhesive layer after drying the aforementioned adhesive layer at 23°C for 2 hours W ₁ = Place the aforementioned adhesive layer after drying at 23°C and 55%RH for 5 hours , and the weight of the adhesive layer after being placed at 60℃95%RH for 5 hours

>Measurement of adhesion and evaluation of peeling> The prepared single-sided protective polarizing film with adhesive layer and the double-sided protective polarizing film with adhesive layer were used as samples. Use a laminating machine to attach the aforementioned sample to the surface of an alkali-free glass plate, and then perform autoclave treatment at 50°C and 5 atm for 15 minutes to achieve complete adhesion. After that, a heavy-duty device was used to measure the adhesive force P ₀ (N/25mm) when the polarizing film was peeled off the surface of the alkali-free glass plate under the conditions of peeling temperature of 23°C, peeling speed of 300 mm/min, and peeling angle of 90 degrees. The above-mentioned sample was attached to the surface of an alkali-free glass plate using a laminating machine, and then autoclaved for 15 minutes under conditions of 50° C. and 5 atm to achieve complete adhesion to obtain a laminated body. Then, the prepared laminated body was immersed in water at 23° C. for 2 hours, and then the laminated body was taken out of the water. After that, a heavy-duty device was used to measure the adhesion force P ₁ (N/25mm) when the aforementioned polarizing film was peeled off the surface of an alkali-free glass plate under the conditions of peeling temperature of 23°C, peeling speed of 300 mm/min, and peeling angle of 90 degrees. Then, the prepared laminated body was immersed in water at 23° C. for 5 hours, and then the laminated body was taken out of the water. Afterwards, a heavy-duty device was used to measure the adhesive force P ₂ (N/25mm) when the polarizing film was peeled off the surface of the alkali-free glass plate under the conditions of peeling temperature of 23°C, peeling speed of 300mm/min and peeling angle of 90 degrees. Then, the prepared laminated body was immersed in water at 23° C. for 500 hours, and then the laminated body was taken out of the water. Thereafter, the polarizing film was visually observed for peeling, and evaluated based on the following criteria. ◎: No peeling was confirmed at all. ○: Wrinkles were observed at the edge of the polarizing film. ×: Obvious peeling was confirmed.

>Evaluation of durability> Peel off the separation film of the single-sided protective polarizing film with the adhesive layer and the double-sided protective polarizing film (15 inches) with the adhesive layer, and use a laminating machine to attach it to alkali-free glass with a thickness of 0.7 mm (made by Corning Incorporated) , EG-XG) on. Next, an autoclave treatment was performed at 50° C. and 0.5 MPa for 15 minutes to completely adhere the polarizing film to the alkali-free glass. Then, after putting them into a heating oven (heating) at 80°C and a constant temperature and humidity machine (humidifying) at 60°C/90%RH, the polarizing plate was evaluated for peeling after 500 hours based on the following criteria. . ◎: No peeling was confirmed at all. ○: Peeling is observed to an extent that cannot be visually confirmed. △: Small peeling that can be visually confirmed is observed. ×: Obvious peeling was confirmed.

>Assess conductive stability> After peeling off the produced separation films of the single-sided protective polarizing film attached to the adhesive layer and the double-sided protective polarizing film attached to the adhesive layer, the surface resistance of the adhesive surface was measured using MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd. Value (Ω/□). Furthermore, after the aforementioned polarizing film was stored in a humidified environment of 60°C/90%RH for 500 hours, the surface resistance value of the adhesive surface was measured in the same manner as above. The change rate (%) of the surface resistance value was calculated according to the following formula and evaluated based on the following criteria. Change rate ΔR (%) = (surface resistance value after storage) × 100 / (surface resistance value before storage) (Evaluation Basis) 〇：0≦ΔR>500 △：500≦ΔR>700 ×：700≦ΔR

[Table 2]

industrial availability The single-sided protective polarizing film with an adhesive layer of the present invention can be used alone or in the form of an optical film laminated thereon to be used in image display devices such as liquid crystal display devices (LCDs) and organic EL display devices.

1‧‧‧Polarizer 2‧‧‧Protective film 3‧‧‧Adhesive 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 and sample (Figure 3) 20‧‧‧Glass plate 20a, 20b‧‧‧Rolled body (roll stock) of single-sided protective polarizing film with adhesive layer 21a, 21b‧‧‧Single-sided protective polarizing film with adhesive layer (with surface protection film) 100‧‧‧Continuous manufacturing system for image display devices 101a, 101b‧‧‧ Polarizing Film Supply Department 151a, 151b‧‧‧ Release Department 152a, 152b‧‧‧ Cutting section 153a, 153b‧‧‧ peeling part 154a, 154b‧‧‧ Coiling section 201a, 201b‧‧‧Laminating Department 300‧‧‧Configuration Replacement Department a‧‧‧Nano slit b‧‧‧penetrating cracks P‧‧‧Image display panel X‧‧‧Conveying part of image display panel

Figure 1 is an example of a schematic cross-sectional view of a single-sided protective polarizing film with an adhesive layer attached thereto according to the present invention. Figure 2 is an example of a conceptual diagram comparing nano-slits and penetrating cracks generated in polarizers. FIG. 3 is a schematic diagram illustrating evaluation items related to nanoslits in Examples and Comparative Examples. FIG. 4 is an example of a photograph showing cracks generated by nanoslits related to the evaluation of Examples and Comparative Examples. FIG. 5 is an example of a schematic cross-sectional view of a continuous manufacturing system for image display devices.

1‧‧‧Polarizer

2‧‧‧Protective film

3‧‧‧Adhesive layer, etc.

4‧‧‧Adhesive layer

5‧‧‧Separate parts

6‧‧‧Surface protection film

10‧‧‧Single-sided protective polarizing film

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

Claims (19)

A single-sided protective polarizing film with an adhesive layer, characterized in that: it has: a single-sided protective polarizing film that only has a protective film on one side of a polarizing element; and, a polarizing element with the aforementioned single-sided protective polarizing film There is an adhesive layer directly on the side or an adhesive layer through the coating layer; the adhesive layer contains a (meth)acrylic polymer as a base polymer and a silane coupling agent, and the silane coupling agent has an adhesive layer selected from the group consisting of epoxy and At least one functional group in the group consisting of a group, an isocyanate group, a mercapto group, an acid anhydride group and an amine group, the weight change rate of the aforementioned adhesive layer calculated according to the following formula (1) is more than 1.1%, and the aforementioned adhesive layer is below The adhesion force P ₀ under the following conditions is below 10N/25mm, and the adhesion force P ₁ under the following conditions is above 1.6N/25mm; weight change rate (%) = {(W ₁ -W ₀ )/W ₀ } ×100 (1) W ₀ = Weight of the adhesive layer after drying the aforementioned adhesive layer at 23°C for 2 hours W ₁ = Place the aforementioned adhesive layer after drying at 23°C 55%RH for 5 hours, The weight adhesive force of the adhesive layer after being placed at 60°C and 95%RH for 5 hours is P ₀ : Attach the adhesive layer of the single-sided protective polarizing film with the adhesive layer to the surface of the alkali-free glass, and place it at 50 After performing autoclave treatment for 15 minutes under the conditions of ℃ and 0.5 atm, the adhesive layer is peeled off from the surface of the alkali-free glass under the conditions of peeling temperature of 23℃, peeling speed of 300mm/min and peeling angle of 90 degrees. Strength; Adhesion P ₁ : It is obtained by attaching the adhesive layer of the aforementioned single-sided protective polarizing film with an adhesive layer to the surface of an alkali-free glass, and performing an autoclave treatment for 15 minutes at 50°C and 0.5atm. For the laminate, immerse the laminate in water at 23°C for 2 hours. After taking the laminate out of the water, peel off the adhesive layer at a peeling temperature of 23°C, a peeling speed of 300 mm/min, and a peeling angle of 90 degrees. Adhesion when peeled off from the aforementioned alkali-free glass surface. The single-sided protective polarizing film with an adhesive layer as claimed in claim 1, wherein the (meth)acrylic polymer contains the following as monomer units: more than 50% by weight of alkyl (meth)acrylate (A) , and the glass transition temperature of its homopolymer is lower than 0°C; and 0.1~20% by weight of high Tg monomer (B), which is selected from alkyl (meth)acrylate (b1) and containing ( At least one of the group consisting of meth)acrylyl monomer (b2), the glass transition temperature of the homopolymer of the aforementioned alkyl (meth)acrylate (b1) is 0°C or above, and the aforementioned (meth)acrylic acid alkyl ester (b1) contains The glass transition temperature of the homopolymer of the acrylyl monomer (b2) is 0° C. or higher and has a heterocyclic ring. The single-sided protective polarizing film with an adhesive layer as claimed in claim 2, wherein the (meth)acrylic polymer contains polar monomers other than the (meth)acrylyl group-containing monomer (b2) as monomer units. , and the polar monomer system is at least one selected from the group consisting of nitrogen-containing monomers, carboxyl-containing monomers, hydroxyl-containing monomers and aromatic group-containing monomers. A single-sided protective polarizing film with an adhesive layer as claimed in claim 3, wherein the nitrogen-containing monomer is a vinyl-based monomer with a lactam ring. A single-sided protective polarizing film with an adhesive layer as claimed in claim 4, wherein the vinyl monomer having a lactam ring is a vinylpyrrolidone monomer. As claimed in claim 5, the single-sided protective polarizing film with an adhesive layer, wherein the vinylpyrrolidone monomer is N-vinylpyrrolidone. A single-sided protective polarizing film with an adhesive layer as claimed in claim 3, wherein the (meth)acrylic polymer contains 0.1 to 5% by weight of the nitrogen-containing monomer as a monomer unit. A single-sided protective polarizing film with an adhesive layer as claimed in claim 3, wherein the (meth)acrylic polymer contains 0.01 to 3% by weight of the carboxyl-containing monomer as a monomer unit. As claimed in Claim 3, the single-sided protective polarizing film with an adhesive layer, wherein the (meth)acrylic polymer contains 0.01 to 1% by weight of the aforementioned hydroxyl-containing monomer as a monomer unit. As claimed in Claim 3, the single-sided protective polarizing film with an adhesive layer, wherein the (meth)acrylic polymer contains 1 to 20% by weight of the aromatic group-containing monomer as a monomer unit. A single-sided protective polarizing film with an adhesive layer as claimed in claim 1, wherein the weight average molecular weight of the (meth)acrylic polymer is less than 1.5 million. For example, the single-sided protective polarizing film with an adhesive layer according to claim 1, wherein the content of the silane coupling agent is 0.01 to 3 parts by weight relative to 100 parts by weight of the (meth)acrylic polymer. A single-sided protective polarizing film with an adhesive layer as claimed in claim 1, wherein the thickness of the polarizing element is less than 12 μm. A single-sided protective polarizing film with an adhesive layer as claimed in claim 1, wherein the polarizer contains a polyvinyl alcohol resin and is configured such that the optical characteristics represented by the monomer transmittance T and the polarization degree P satisfy the conditions of the following formula : P>-(10 ^0.929T-42.4 -1)×100 (but, T<42.3), or P≧99.9 (but, T≧42.3). A single-sided protective polarizing film with an adhesive layer as claimed in claim 1, wherein the polarizer contains less than 25% by weight of boric acid relative to the total amount of the polarizer. The single-sided protective polarizing film with an adhesive layer as claimed in any one of claims 1 to 15, wherein a separator is provided on the adhesive layer. For example, the single-sided protective polarizing film with an adhesive layer as claimed in claim 16 is a roll. An image display device having a single-sided protective polarizing film with an adhesive layer as claimed in any one of claims 1 to 15. A continuous manufacturing method of an image display device, including the following steps: releasing the aforementioned adhesive agent from the roll of the single-sided protective polarizing film of the aforementioned adhesive agent layer as claimed in claim 17 and conveying it through the aforementioned separator A layer of single-sided protective polarizing film is continuously attached to the surface of the image display panel through the aforementioned adhesive layer.