TWI828796B - Image display device - Google Patents

Abstract

The present invention is an image display device, which is provided with a front transparent member, a polarizing film and an image display unit in sequence through an adhesive layer or adhesive layer; the polarizing film is formed by adsorbing and orienting iodine to a polyvinyl alcohol-based film. Polarizing film; at least one of the aforementioned polarizing film, the aforementioned adhesive layer and the aforementioned adhesive layer contains a hindered amine compound; the aforementioned hindered amine compound is soluble in more than 1 part by weight of water based on 100 parts by weight of water at 25°C. Hindered amine compound; the aforementioned polarizing film satisfies the conditions shown in the general formula (1): General formula (1): X (weight %) > 0.01 (in the general formula (1), After being placed under the conditions, the content of the hindered amine compound in the polarizing film in the laminated body is obtained by laminating glass plates on both sides of the polarizing film through the aforementioned adhesive layer, and the aforementioned polarizing film is formed on the aforementioned polarizing film. At least one side of the film is pasted with a transparent protective film through the aforementioned adhesive layer). This image display device has an excellent effect of suppressing a decrease in transmittance of a single unit caused by coloration of the polarizing film in a high-temperature environment.

Description

Image display device

The present invention relates to an image display device.

Background of the invention In the past, polarizing films used in various image display devices such as liquid crystal displays and organic EL displays have been dyed (containing dichroic films such as iodine or dichroic dyes) to achieve both high transmittance and high polarization. Substance) polyvinyl alcohol based film. This polarizing film is produced by subjecting a polyvinyl alcohol-based film to various treatments such as swelling, dyeing, cross-linking, and stretching in a bath, followed by washing and drying. In addition, the polarizing film is usually used as a polarizing film (polarizing plate) in which a protective film such as cellulose triacetate is bonded to one or both sides using an adhesive.

The aforementioned polarizing film can be laminated with other optical layers as needed to form a laminated polarizing film (optical laminated body) for use. The aforementioned polarizing film or the aforementioned laminated polarizing film (optical laminated body) is used in image display units such as liquid crystal cells or organic EL elements. It is bonded to a front transparent member such as a front transparent plate (window layer) or a touch panel on the viewing side through an adhesive layer or adhesive layer to make the various image display devices mentioned above for use.

In recent years, in addition to being used in mobile devices such as mobile phones and tablet computer terminals, the various image display devices have also been used in vehicle-mounted image display devices such as car navigation devices and rearview monitor recorders, and their uses have become increasingly widespread. Widespread. Therefore, the polarizing film or the laminated polarizing film is required to have high durability in a harsher environment (such as a high-temperature environment) than has been required in the past, and a polarizing film for the purpose of ensuring the durability has been proposed ( Patent document 1).

In addition, it is known that dye-based polarizing films using dichroic dyes such as azo compounds generally have better light resistance under high-temperature and high-humidity conditions than iodine-based polarizing films (iodine is adsorbed and oriented to a polyvinyl alcohol-based film). Polarizing film) is excellent (Patent Document 2), and in order to improve the fading of a polarizing plate having this dye-based polarizing film in a light resistance test, it has been disclosed that the adhesive to be used for the polarizing plate can contain a hindered amine compound ( Patent document 3).

In order to improve the heat resistance of the polarizing plate, it is specifically disclosed that a water-insoluble HALS (Hindered Amine Light Stabilizer) is blended into an adhesive containing an epoxy compound (Patent Document 4).

Prior technical literature patent documents Patent Document 1: Japanese Patent Publication No. 2012-516468 Patent Document 2: Japanese Patent Application Publication No. 2001-240762 Patent Document 3: Japanese Patent Application Publication No. 2005-338343 Patent Document 4: Korean Patent Application Publication No. 10-2015-0114149

Contents of the invention The problem to be solved by the invention On the other hand, as mentioned above, when a polarizing film or a laminated polarizing film using an iodine-based polarizing film, which is said to have poorer light resistance under high-temperature and high-humidity conditions than dye-based polarizing films, is exposed to a high temperature environment, the polarizing film will be colored. , but has the problem of reduced monomer transmittance. In particular, in an image display device formed by laminating the above-mentioned polarizing film or laminated polarizing film between an image display unit and a front transparent member through an adhesive layer or adhesive layer, the coloring of the polarizing film is remarkable, and there is a monomer The transmittance will be significantly reduced.

In view of the above, an object of the present invention is to provide an image display device that is excellent in suppressing a decrease in transmittance of a polarizing film due to coloration of a polarizing film in a high-temperature environment.

means to solve problems That is, the present invention relates to an image display device, which is provided with a front transparent member, a polarizing film and an image display unit in sequence through an adhesive layer or adhesive layer; the aforementioned polarizing film has iodine adsorption and orientation to a polyvinyl alcohol-based film The polarizing film formed; at least one of the aforementioned polarizing film, the aforementioned adhesive layer and the aforementioned adhesive layer contains a hindered amine compound; the aforementioned hindered amine compound is soluble in 1 part by weight relative to 100 parts by weight of water at 25°C The above water-soluble hindered amine compound; the aforementioned polarizing film satisfies the conditions shown in the general formula (1): General formula (1): X (weight %) > 0.01 (in the general formula (1), , the content of hindered amine compounds in the polarizing film in the laminated body after being left under conditions for 24 hours. The laminated system is made by laminating glass plates through the aforementioned adhesive layer on both sides of the polarizing film, and the aforementioned polarizing film is A transparent protective film is bonded to at least one side of the polarizing film through the adhesive layer).

Invention effect Although the details of the mechanism of the effect of the image display device of the present invention are still unclear, we speculate as follows. However, the present invention is not limited to this explanation of the mechanism of action.

The image display device of the present invention is provided with a front transparent member, a polarizing film, and an image display unit in sequence through an adhesive layer or an adhesive layer. At least one of the aforementioned polarizing film, the aforementioned adhesive layer, and the aforementioned adhesive layer contains a composition corresponding to 100 parts by weight of water at 25°C can dissolve more than 1 part by weight of a water-soluble hindered amine compound. Furthermore, the polarizing film has an iodine-based polarizing film formed by adsorbing and orienting iodine to a polyvinyl alcohol-based film. As described in Patent Documents 2 and 3 mentioned above, iodine-based polarizing films generally have poorer durability such as heat resistance than dye-based polarizing films. It is presumed that the reason for this is that the iodine contained in the polarizing film accelerates the degradation of polyvinyl alcohol due to polyvinyl alcohol in high-temperature environments. This is due to a deterioration phenomenon called polyene that occurs due to the dehydration reaction.

On the other hand, when the hindered amine compound contained in at least one of the polarizing film, the adhesive layer and the adhesive layer of the present invention is exposed to a high temperature environment, it will interact with the moisture existing inside the image display device ( (Moisture present in the adhesive layer, adhesive layer, etc.) moves (resides) inside the image display device together, so it is speculated that part of the water-soluble hindered amine compound penetrates into the iodine-based polarizing film. As a result, it is speculated that the water-soluble hindered amine compound in the polarizing film can effectively capture the free radicals generated in the above-mentioned polyene reaction in a high temperature environment. Therefore, the image display device of the present invention can suppress the monomer transmission caused by the coloration of the polarizing film. The rate decreases.

Form used to implement the invention FIG. 1 is a schematic cross-sectional view showing one form of the image display device of the present invention. In the image display device 100 of FIG. 1 , the front transparent member 80 and the polarizing film 10 are bonded through an adhesive layer or adhesive layer 20 , and the image display unit 90 and the polarizing film 10 are bonded through an adhesive layer or adhesive layer 30 . combine.

Figure 2 is a schematic cross-sectional view showing one form of the single-sided protective polarizing film of the present invention. The single-sided protective polarizing film 101 in Figure 2 shows one aspect of the polarizing film 10. In the polarizing film 10, the polarizing film 11 and the transparent protective film 13 are bonded together through an adhesive layer or adhesive layer 50.

Figure 3 is a schematic cross-sectional view showing one form of the double-sided protective polarizing film of the present invention. The double-sided protective polarizing film 102 in Figure 3 shows one aspect of the polarizing film 10. In the polarizing film 10, the polarizing film 11 and the transparent protective film 13 are bonded through an adhesive layer or adhesive layer 50, and the polarizing film 11 The transparent protective film 12 is bonded to the transparent protective film 12 through an adhesive layer or adhesive layer 40 .

The image display device of the present invention is provided with a front transparent member, a polarizing film and an image display unit in sequence through an adhesive layer or an adhesive layer. At least one of the aforementioned polarizing film, the aforementioned adhesive layer and the aforementioned adhesive layer contains a hindered amine system. The compound, the aforementioned hindered amine compound is a water-soluble hindered amine compound that can dissolve at least 1 part by weight relative to 100 parts by weight of water at 25°C. The aforementioned hindered amine compounds may be used alone or in combination of two or more types.

The aforementioned hindered amine compound moves (resides) inside the image display device together with the moisture present inside the image display device (moisture content present in the adhesive layer, adhesive layer, etc.), thereby suppressing coloration of the polarizing film in a high-temperature environment. From this point of view, the aforementioned hindered amine compound should be soluble in at least 2 parts by weight relative to 100 parts by weight of water at 25°C, and soluble in 5 parts by weight relative to 100 parts by weight of water at 25°C. The above is better.

In addition, from the viewpoint of efficiently capturing free radicals generated in the polyene reaction, the molecular weight of the hindered amine compound is preferably 1,000 or less, more preferably 500 or less, and still more preferably 300 or less.

>Hindered amine compounds> The hindered amine compounds of the present invention are secondary amines or tertiary amines in which an alkyl group is substituted on the carbon adjacent to the amine group to stereoprotect the amine group. For example, those having the following structure Organic compounds, etc. In addition, the exemplified compounds may contain structures that are insoluble at more than 1 part by weight per 100 parts by weight of water at 25°C. However, anyone familiar with the art can consider technical common sense and immediately confirm that the exemplified compounds are Whether 100 parts by weight of water at 25°C can dissolve more than 1 part by weight. [Chemical formula 1] …(1) (In the general formula (1), R ¹ represents an oxygen radical, a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 30 carbon atoms, a hydroxyalkyl group, a hydroxyalkoxy group or an alkoxy group, and R ² to R ⁵ independently represents a hydrogen atom or an alkyl group with 1 to 10 carbon atoms, and n represents 0 or 1). In addition, the left side of the dotted line part in the general formula (1) represents an arbitrary organic group.

The aforementioned hindered amine compounds are known compounds, including, for example, 2,2,6,6-tetraalkylpiperidine described in columns 5 to 11 of the specification of U.S. Patent No. 4,619,956 and columns 3 to 5 of the specification of U.S. Patent No. 4,839,405. compounds or their acid addition salts or their complexes with metal compounds.

Examples of the compound having the above organic group include compounds represented by the following general formulas (2) to (5). [Chemical formula 2] …(2) (In the general formula (2), R ¹ represents an oxygen radical, a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 30 carbon atoms, a hydroxyalkyl group, a hydroxyalkoxy group or an alkoxy group, and R ² to R ⁵ independently represents a hydrogen atom or an alkyl group with 1 to 10 carbon atoms, R ⁶ represents a hydrogen atom or an alkyl group with 1 to 10 carbon atoms, a hydroxyl group or an aryl group, and n represents 0 or 1). [Chemical formula 3] ...(3) (In the general formula (3), R ¹ to R ⁵ and n are the same as above, and R ⁷ and R ⁸ independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, an acyl group or an aryl group). [Chemical formula 4] …(4) (In the general formula (4), R ¹ to R ⁵ and n are the same as above, and R ⁹ to R ¹¹ independently represent a hydrogen atom or an alkyl group with 1 to 10 carbon atoms, a acyl group, an amine group, or an alkoxy group. group, hydroxyl or aryl group). [Chemical formula 5] …(5) (In the general formula (5), R ¹ to R ⁵ and n are the same as above. R ¹² represents a hydrogen atom or an alkyl group with 1 to 10 carbon atoms, an amino group, an alkoxy group, a hydroxyl group or an aryl group. ).

In the aforementioned general formulas (1) to (5), R ¹ is preferably an oxygen radical, a hydrogen atom, a hydroxyl group or an alkyl group, and oxygen radical is more preferred from the viewpoint of effectively inhibiting the accelerated deterioration of polyvinyl alcohol. . Furthermore, in the aforementioned general formulas (1) to (5), R ² to R ⁵ are preferably alkyl groups having 1 to 6 carbon atoms, and more preferably alkyl groups having 1 to 3 carbon atoms, from the viewpoint of ease of acquisition and water solubility. good. Furthermore, in the aforementioned general formula (2), from the viewpoint of ease of acquisition and water solubility, R ⁶ is preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and a hydrogen atom is more preferred. Furthermore, in the aforementioned general formula (3), from the viewpoint of ease of acquisition and water solubility, R ⁷ and R ⁸ are preferably independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and a hydrogen atom is more preferred. Furthermore, in the general formula (4), from the viewpoint of ease of acquisition and water solubility, R ⁹ to R ¹¹ are preferably hydrogen atoms or alkyl groups having 1 to 10 carbon atoms. In the general formula (5), R ¹² is preferably a hydroxyl group, an amino group or an alkoxy group from the viewpoint of availability and water solubility. In the aforementioned general formulas (1) to (5), n is preferably 1 from the viewpoint of ease of acquisition.

>Polarizing film> The polarizing film of the present invention has a polarizing film formed by adsorbing and orienting iodine to a polyvinyl alcohol-based film.

The polyvinyl alcohol (PVA)-based film can be used without particular limitation, having light transmittance in the visible light region and capable of dispersing and adsorbing iodine. In addition, the thickness of the PVA-based film generally used as the original board is preferably about 1 to 100 μm, and more preferably about 1 to 50 μm, and the width is preferably about 100 to 5000 mm.

Examples of the material of the polyvinyl alcohol-based film include polyvinyl alcohol or its derivatives. Derivatives of the aforementioned polyvinyl alcohol include, for example, polyvinyl formal and polyvinyl acetal; olefins such as ethylene and propylene; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid and their alkyl esters; and acrylic acid amides. Wait for the reformers to wait. The average degree of polymerization of the aforementioned polyvinyl alcohol is preferably about 100 to 10,000, more preferably about 1,000 to 10,000, and more preferably about 1,500 to 4,500. In addition, the saponification degree of the aforementioned polyvinyl alcohol is preferably about 80 to 100 mol%, and more preferably about 95 to 99.95 mol%. In addition, the above-mentioned average degree of polymerization and the above-mentioned saponification degree can be obtained in accordance with JIS K 6726.

The polyvinyl alcohol-based film may also contain additives such as plasticizers and surfactants. Examples of the plasticizer include polyols such as glycerin, diglycerin, triglycerin, ethylene glycol, propylene glycol, and polyethylene glycol, and their condensates. The usage amount of the aforementioned additives is not particularly limited, but for example, it is preferably about 20% by weight or less in the polyvinyl alcohol-based film.

The iodine content of the polarizing film is preferably 1% by weight or more and 15% by weight or less. From the viewpoint of suppressing fading during the durability test, the iodine content of the polarizing film is preferably 1.5% by weight or more, and more preferably 2% by weight or more. From the viewpoint of preventing polyene, the iodine content of the polarizing film is preferably 1.5% by weight or more, and more preferably 2% by weight or more. The content is 12% by weight or less, and more preferably 10% by weight or less.

When the polarizing film contains the hindered amine compound, the content of the hindered amine compound is preferably 20% by weight or less. The content of the hindered amine compound in the polarizing film is preferably 0.005% by weight or more, more preferably 0.01% by weight or more, and 0.1% by weight or more, from the viewpoint of suppressing the reduction in monomer transmittance caused by coloration of the polarizing film in a high-temperature environment. More preferably, it is 15% by weight or less, more preferably 12% by weight or less, and still more preferably 10% by weight or less.

>Manufacturing method of polarizing film> The manufacturing method of the polarizing film can be obtained by subjecting the polyvinyl alcohol-based film to any swelling step and cleaning step, and at least a dyeing step, a cross-linking step and a stretching step. When the aforementioned polarizing film contains the aforementioned hindered amine compound, as long as the treatment bath in any one or more of the aforementioned swelling step, the aforementioned washing step, the aforementioned dyeing step, the aforementioned cross-linking step and the aforementioned stretching step contains the aforementioned hindered amine compound. Compounds are enough. The content of the hindered amine compound and the content of iodine contained in the polarizing film can be determined by any one of the treatment baths in the swelling step, dyeing step, cross-linking step, stretching step and cleaning step. The concentration of the hindered amine compound, the concentration of iodine, potassium iodide, etc., and the processing temperature and processing time of each of the above-mentioned treatment baths are controlled. In particular, when a washing step is performed after a dyeing step, a cross-linking step, and an extension step, the hindered amine compound can be used in consideration of the processing conditions of the dyeing step, the cross-linking step, and the extension step. From the viewpoint that components such as iodine are eluted from the polyvinyl alcohol-based film or can be adsorbed to the polyvinyl alcohol-based film, the content of the hindered amine compound and the content of iodine can be easily adjusted to the desired range in the washing step. .

In addition, each processing bath in the aforementioned swelling step, the aforementioned dyeing step, the aforementioned cross-linking step, the aforementioned extending step, and the aforementioned washing step may also contain additives such as zinc salts, pH adjusters, pH buffers, and other salts. Examples of the zinc salt include zinc halides such as zinc chloride and zinc iodide; inorganic zinc salts such as zinc sulfate and zinc acetate. Examples of the pH adjuster include strong acids such as hydrochloric acid, sulfuric acid, and nitric acid, or strong bases such as sodium hydroxide and potassium hydroxide. Examples of the pH buffering agent include carboxylic acids such as acetic acid, oxalic acid, and citric acid and their salts, or inorganic weak acids such as phosphoric acid and carbonic acid and their salts. Examples of the aforementioned other salts include chlorides such as sodium chloride, potassium chloride, and barium chloride; nitrates such as sodium nitrate and potassium nitrate; sulfates such as sodium sulfate and potassium sulfate; and alkali metal and alkaline earth metal salts. .

The concentration of the hindered amine compound contained in any of the aforementioned treatment baths will be affected by the number of treatments, treatment time, treatment temperature, etc. of each treatment, so it cannot be determined uniformly. However, it can effectively control the hindrance in the polarizing film. From the viewpoint of the content of the amine compound, it is generally preferably 0.01% by weight or more, more preferably 0.05% by weight or more, still more preferably 0.1% by weight or more, and preferably 30% by weight or less, and more preferably 20% by weight or less. , preferably less than 10% by weight.

The aforementioned swelling step is a treatment step in which the polyvinyl alcohol-based film is immersed in a swelling bath, which can remove dirt and anti-caking agents on the surface of the polyvinyl alcohol-based film and swell the polyvinyl alcohol-based film to suppress dyeing unevenness. The aforementioned swelling bath can generally use water, distilled water, pure water and other media containing water as the main component. The aforementioned swelling bath can also appropriately add surfactant, alcohol, etc. according to the general method.

The temperature of the aforementioned swelling bath should be about 10 to 60°C, preferably about 15 to 45°C, and even more preferably about 18 to 35°C. In addition, since the swelling degree of the polyvinyl alcohol-based film will be affected by the temperature of the swelling bath, the immersion time in the aforementioned swelling bath cannot be determined uniformly, but it is preferably about 5 to 300 seconds, and about 10 to 200 seconds. Best, about 20 to 100 seconds is better. The aforementioned swelling step can be performed only once or as many times as necessary.

The aforementioned dyeing step is a treatment step in which the polyvinyl alcohol-based film is immersed in a dyeing bath (iodine solution), which can adsorb iodine and orient the polyvinyl alcohol-based film. The aforementioned iodine solution is generally an aqueous iodine solution and contains iodine and iodide as a dissolution aid. Examples of the aforementioned iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, titanium iodide, etc. . Among these, potassium iodide is suitable from the viewpoint of controlling the potassium content in the polarizing film.

In the aforementioned dyeing bath, the iodine concentration is preferably about 0.01 to 1% by weight, and more preferably about 0.02 to 0.5% by weight. In the aforementioned dyeing bath, the concentration of the aforementioned iodide is preferably about 0.01 to 20% by weight, preferably about 0.05 to 10% by weight, and more preferably about 0.1 to 5% by weight.

The temperature of the aforementioned dyeing bath should be about 10 to 50°C, preferably about 15 to 45°C, and even more preferably about 18 to 30°C. In addition, since the dyeing degree of the polyvinyl alcohol-based film will be affected by the temperature of the dyeing bath, the immersion time in the aforementioned dyeing bath cannot be determined uniformly, but it is preferably about 10 to 300 seconds, and it can be changed from about 20 to 240 seconds. good. The aforementioned dyeing step may be performed only once, or may be performed multiple times as needed.

The aforementioned cross-linking step is a treatment step in which the polyvinyl alcohol-based film is immersed in a treatment bath (cross-linking bath) containing a boron compound. The boron compound can cross-link the polyvinyl alcohol-based film and adsorb iodine molecules or dye molecules to the the cross-linked structure. Examples of the boron compound include boric acid, borate, borax, and the like. The cross-linking bath is generally an aqueous solution, but may also be a mixed solution of an organic solvent miscible with water and water, for example. Furthermore, from the viewpoint of controlling the potassium content in the polarizing film, the cross-linking bath preferably contains potassium iodide.

In the cross-linking bath, the concentration of the boron compound is preferably about 1 to 15% by weight, preferably about 1.5 to 10% by weight, and more preferably about 2 to 5% by weight. Furthermore, when potassium iodide is used in the cross-linking bath, the concentration of potassium iodide in the cross-linking bath is preferably about 1 to 15% by weight, preferably about 1.5 to 10% by weight, and more preferably about 2 to 5% by weight.

The temperature of the aforementioned cross-linking bath is preferably about 20 to 70°C, and more preferably about 30 to 60°C. In addition, since the degree of cross-linking of the polyvinyl alcohol-based film will be affected by the temperature of the cross-linking bath, the immersion time in the aforementioned cross-linking bath cannot be determined uniformly, but it is preferably about 5 to 300 seconds, and 10 to 200 seconds. A clock or so is better. The aforementioned cross-linking step may be performed only once, or may be performed multiple times as needed.

The aforementioned stretching step is a processing step of stretching the polyvinyl alcohol-based film in at least one direction at a predetermined ratio. Generally speaking, a polyvinyl alcohol-based film is uniaxially stretched in the conveyance direction (longitudinal direction). The aforementioned stretching method is not particularly limited, and either a wet stretching method or a dry stretching method can be used. The aforementioned extension steps can be performed only once or as many times as necessary. The aforementioned stretching step can be performed at any stage during the production of the polarizing film.

The treatment bath (extension bath) of the aforementioned wet extension method can generally use solvents such as water or an organic solvent miscible with water and a mixed solution of water. From the viewpoint of controlling the potassium content in the polarizing film, the stretching bath preferably contains potassium iodide. When potassium iodide is used in the aforementioned extension bath, the concentration of potassium iodide in the extension bath is preferably about 1 to 15% by weight, preferably about 2 to 10% by weight, and more preferably about 3 to 6% by weight. In addition, from the viewpoint of suppressing film breakage during stretching, the boron compound is preferably contained in the treatment bath (stretching bath). In this case, the concentration of the boron compound in the stretching bath is preferably about 1 to 15% by weight, and 1.5 to 10% by weight. About % is preferred, and about 2 to 5% by weight is more preferred.

The temperature of the aforementioned extension bath should be about 25 to 80°C, preferably about 40 to 75°C, and more preferably about 50 to 70°C. In addition, since the degree of stretching of the polyvinyl alcohol-based film will be affected by the temperature of the stretching bath, the immersion time in the aforementioned stretching bath cannot be determined uniformly, but it is preferably about 10 to 800 seconds, and more frequently about 30 to 500 seconds. good. In addition, the stretching treatment of the aforementioned wet stretching method may also be performed simultaneously with any one or more processing steps among the aforementioned swelling step, the aforementioned dyeing step, the aforementioned cross-linking step, and the aforementioned washing step.

Examples of the dry stretching method include a roller stretching method, a heated roller stretching method, a compression stretching method, and the like. In addition, the aforementioned dry stretching method can also be performed simultaneously with the aforementioned drying step.

The total stretch ratio (cumulative stretch ratio) applied to the polyvinyl alcohol-based film can be appropriately set according to the purpose, but is preferably about 2 to 7 times, preferably about 3 to 6.8 times, and more preferably about 3.5 to 6.5 times.

The aforementioned cleaning step is a treatment step in which the polyvinyl alcohol-based film is immersed in a cleaning bath, which can remove foreign matter remaining on the surface of the polyvinyl alcohol-based film. The aforementioned cleaning bath can generally use water, distilled water, pure water and other media with water as the main component. In addition, from the viewpoint of controlling the potassium content in the polarizing film, the cleaning bath may also contain potassium iodide. In this case, the concentration of potassium iodide in the cleaning bath is preferably about 1 to 10% by weight, and 1.5 to 4% by weight. About 1.8 to 3.8% by weight is more preferred.

The temperature of the aforementioned cleaning bath should be about 5 to 50°C, preferably about 10 to 40°C, and even more preferably about 15 to 30°C. In addition, since the degree of cleaning of the polyvinyl alcohol-based film will be affected by the temperature of the cleaning bath, the immersion time in the aforementioned cleaning bath cannot be determined uniformly, but it is preferably about 1 to 100 seconds, and 2 to 50 seconds. About 10 seconds is better, and 3 to 20 seconds is better. The aforementioned swelling step can be performed only once, or multiple times as needed.

The manufacturing method of the aforementioned polarizing film may also include a drying step. The aforementioned drying step is a step of drying the polyvinyl alcohol-based film washed in the aforementioned washing step to obtain a polarizing film. A polarizing film with a desired moisture content can be obtained by drying. The aforementioned drying can be performed by any appropriate method, and examples thereof include natural drying, air drying, and heating drying.

The aforementioned drying temperature is preferably about 20 to 150°C, and more preferably about 25 to 100°C. In addition, since the degree of drying of the polarizing film will be affected by the drying temperature, the aforementioned drying time cannot be determined uniformly, but it is preferably about 30 to 600 seconds, and preferably about 60 to 300 seconds. The aforementioned drying step may be performed only once, or may be performed multiple times as needed.

The thickness of the aforementioned polarizing film is preferably about 1 to 50 μm, and more preferably about 1 to 25 μm. In particular, in order to obtain a polarizing film with a thickness of 8 μm or less, the following method for manufacturing a thin polarizing film using a laminate including a polyvinyl alcohol-based resin layer formed on a resin base material such as a thermoplastic resin can be applied. Specifically as the aforementioned polyvinyl alcohol-based film.

>Manufacturing method of polarizing film (thin polarizing film)> The manufacturing method of a polarizing film (thin polarizing film) includes the following steps: forming a polyvinyl alcohol-based resin layer containing a polyvinyl alcohol-based resin on one side of a long thermoplastic resin base material to prepare a laminate, and further While transporting the obtained laminated body in the longitudinal direction, any insolubilization treatment step, a cross-linking treatment step and a washing treatment step are performed on the said laminated body, and at least an air auxiliary stretching treatment step, a dyeing treatment step and an aqueous extension treatment step are performed on the said laminated body And get. When the aforementioned polarizing film contains the aforementioned hindered amine compound, as long as any one or more of the aforementioned insolubilization treatment step, the aforementioned cross-linking treatment step, the aforementioned washing treatment step, the aforementioned dyeing treatment step, and the aforementioned water extension treatment step, The treatment bath may contain the aforementioned hindered amine compound. The content of the hindered amine compound and the iodine content contained in the polarizing film can be determined through the insolubilization treatment step, the cross-linking treatment step, the cleaning treatment step, the dyeing treatment step and the water extension treatment step. The concentration of the hindered amine compound, the concentration of iodine, potassium iodide, etc. contained in each treatment bath, the treatment temperature and the treatment time of each treatment bath are controlled. Especially when a washing step is performed, components such as a hindered amine compound or iodine can be eluted from the polyvinyl alcohol-based film, taking into account the processing conditions of the dyeing step and the water extension step. From the viewpoint of adsorbing the polyvinyl alcohol-based film to the polyvinyl alcohol-based film, the content of the hindered amine compound and the content of the iodine can be easily adjusted to a desired range in the cleaning step.

The concentration of the hindered amine compound contained in any of the aforementioned treatment baths will be affected by the number of treatments, treatment time, treatment temperature, etc. of each treatment, so it cannot be determined uniformly. However, it can effectively control the hindrance in the polarizing film. From the viewpoint of the content of the amine compound, it is generally preferably 0.01% by weight or more, more preferably 0.05% by weight or more, still more preferably 0.1% by weight or more, and preferably 30% by weight or less, and more preferably 25% by weight or less. , preferably less than 20% by weight.

>Steps to prepare laminates> Any appropriate method can be used to produce the laminate, and an example is a method of applying a coating liquid containing the polyvinyl alcohol-based resin (PVA-based resin) to the surface of the thermoplastic resin base material and drying it. The thickness of the aforementioned thermoplastic resin base material is preferably about 20 to 300 μm, and more preferably about 50 to 200 μm. The thickness of the aforementioned PVA-based resin layer is preferably about 3 to 40 μm, and more preferably about 3 to 20 μm.

From the viewpoint that the aforementioned thermoplastic resin base material can absorb water and greatly reduce the elongation stress, thereby allowing high-rate elongation, the water absorption rate is preferably about 0.2% or more, and more preferably about 0.3% or more. On the other hand, from the viewpoint of preventing the dimensional stability of the thermoplastic resin base material from significantly reducing, which would cause deterioration in the appearance of the polarizing film obtained, the water absorption rate of the thermoplastic resin base material is preferably about 3% or less, and 1% Left to right or below is better. In addition, the water absorption rate can be adjusted, for example, by introducing a modifying group into the constituent material of the thermoplastic resin base material. The aforementioned water absorption rate is a value obtained in accordance with JIS K 7209.

From the viewpoint of suppressing the crystallization of the PVA-based resin layer and ensuring sufficient extensibility of the laminate, the glass transition temperature (Tg) of the thermoplastic resin base material is preferably about 120°C or less. In addition, in view of plasticizing the thermoplastic resin base material with water and enabling good stretching in water, the glass transition temperature (Tg) is preferably about 100°C or less, more preferably about 90°C or less. On the other hand, from the viewpoint of preventing defects such as deformation of the thermoplastic resin base material during coating and drying of the coating liquid and producing a good laminate, the glass transition temperature of the thermoplastic resin base material is preferably about 60°C or higher. . In addition, the glass transition temperature can be adjusted, for example, by heating using a crystallized material that can introduce a modified group into a constituent material of the thermoplastic resin base material. The aforementioned glass transition temperature (Tg) is a value obtained in accordance with JIS K 7121.

Any appropriate thermoplastic resin may be used as the constituent material of the aforementioned thermoplastic resin base material. Examples of the thermoplastic resin include ester-based resins such as polyethylene terephthalate-based resins, cycloolefin-based resins such as norbornene-based resins, olefin-based resins such as polypropylene, polyamide-based resins, and polycarbonate-based resins. And its copolymer resins, etc. Among these, norbornene-based resin and amorphous (non-crystalline) polyethylene terephthalate-based resin are preferred, and the thermoplastic resin base material not only has excellent elongation, but also can suppress elongation. From the viewpoint of crystallization, it is more suitable to use amorphous (amorphous) polyethylene terephthalate resin. Amorphous (non-crystalline) polyethylene terephthalate-based resins include copolymers containing isophthalic acid and/or cyclohexanedicarboxylic acid as dicarboxylic acids, or cyclohexanedimethanol. or diethylene glycol as a copolymer of glycol.

Before forming the PVA-based resin layer, the thermoplastic resin base material may be subjected to surface treatment (such as corona treatment, etc.), or an easy-adhesion layer may be formed on the thermoplastic resin base material. By performing the above-described treatment, the adhesion between the thermoplastic resin base material and the PVA-based resin layer can be improved. Furthermore, the thermoplastic resin base material may be stretched before forming the PVA-based resin layer.

The coating liquid is a solution in which a PVA-based resin is dissolved in a solvent. Examples of the solvent include water, dimethylsulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, various glycols, polyhydric alcohols such as trimethylolpropane, and ethylene glycol. Amines such as ethylenediamine and diethylenetriamine are preferably water. These can be used individually or in combination of 2 or more types. From the viewpoint of forming a uniform coating film that adheres closely to the thermoplastic resin base material, the PVA-based resin concentration of the coating liquid is preferably about 3 to 20 parts by weight relative to 100 parts by weight of the solvent.

From the viewpoint of improving the orientation of polyvinyl alcohol molecules through stretching, it is preferable to blend a halide into the coating liquid. Any appropriate halide may be used as the aforementioned halide, and examples thereof include iodide and sodium chloride. Examples of the iodide include potassium iodide, sodium iodide, lithium iodide, and the like, and potassium iodide is preferred. The concentration of the halide in the coating liquid is preferably about 5 to 20 parts by weight, and more preferably about 10 to 15 parts by weight based on 100 parts by weight of the PVA resin.

In addition, additives may be blended into the coating liquid. Examples of the additives include plasticizers such as ethylene glycol and glycerol; surfactants such as nonionic surfactants; and the like.

Examples of the coating method of the coating liquid can be any appropriate method, such as roller coating, spin coating, wire bar coating, dip coating, die coating, curtain coating, and spray coating. method, blade coating method (comma coating method, etc.), etc. In addition, the drying temperature of the coating liquid is preferably about 50°C or higher.

>Aerial auxiliary extension processing steps> The above-mentioned in-air auxiliary stretching treatment step can stretch while suppressing crystallization of the thermoplastic resin base material, so the laminate can be stretched at a high magnification ratio. The stretching method of the aforementioned in-air auxiliary stretching treatment step can be fixed-end stretching (for example, using a tenter stretching machine to stretch), or free-end stretching (for example, uniaxial stretching of the laminate through rollers with different peripheral speeds) method), and from the perspective of obtaining high optical properties, it is appropriate to extend the free end.

The stretching ratio of the aforementioned aerial auxiliary stretching processing step should be about 2 to 3.5 times. The aforementioned air-assisted extension processing can be performed in one stage or in multiple stages. When it is carried out in multiple stages, the extension ratio is the product of the extension ratios of each stage.

The stretching temperature of the above-mentioned in-air auxiliary stretching treatment step can be set to any appropriate value according to the forming material of the thermoplastic resin base material, the stretching method, etc., for example, it is preferably above the glass transition temperature (Tg) of the thermoplastic resin base material, and the aforementioned glass transition temperature (Tg) +10°C or more is preferred, and the glass transition temperature (Tg) +15°C or above is more preferred. On the other hand, the upper limit of the stretching temperature is preferably 170°C from the viewpoint of suppressing the rapid progression of crystallization of the PVA-based resin and thereby suppressing problems caused by crystallization (for example, hindering the orientation of the PVA-based resin layer due to stretching). about.

>Insolubilization treatment steps> If necessary, an insolubilization treatment step can also be performed after the aforementioned air auxiliary extension treatment step and before the dyeing treatment step or the water extension treatment step. The aforementioned insolubilization treatment step is typically performed by immersing the PVA-based resin layer in a boric acid aqueous solution. By performing an insolubilization treatment step, the PVA-based resin layer can be given water resistance and prevent the PVA from being oriented from being reduced when immersed in water. The concentration of the boric acid aqueous solution is preferably about 1 to 5 parts by weight relative to 100 parts by weight of water. The liquid temperature of the insoluble treatment bath should be about 20~50℃.

>Dyeing Processing Steps> The aforementioned dyeing treatment step is performed by dyeing the PVA-based resin layer with iodine. Examples of the adsorption method include: a method of immersing the PVA-based resin layer (laminated body) in a dyeing liquid containing iodine, a method of applying the dyeing liquid on the PVA-based resin layer, and a method of spraying the dyeing liquid onto the PVA A method in which a PVA-based resin layer (laminated body) is immersed in a dyeing solution containing iodine is preferred.

The blending amount of iodine in the aforementioned dyeing bath is preferably about 0.05 to 0.5 parts by weight relative to 100 parts by weight of water. In order to improve the solubility of iodine in water, it is suitable to blend the aforementioned iodide into the aqueous iodine solution. The blending amount of the aforementioned iodide is preferably about 0.1 to 10 parts by weight relative to 100 parts by weight of water, and more preferably about 0.3 to 5 parts by weight. In order to suppress the dissolution of PVA-based resin, the liquid temperature of the dyeing bath should be about 20 to 50°C. In addition, from the viewpoint of ensuring the transmittance of the PVA-based resin layer, the immersion time is preferably about 5 seconds to 5 minutes, and more preferably about 30 seconds to 90 seconds. From the perspective of obtaining a polarizing film with good optical properties, the content ratio of iodine and iodide in the iodine aqueous solution is preferably about 1:5 to 1:20, and more preferably about 1:5 to 1:10.

>Cross-linking processing steps> If necessary, a cross-linking treatment step can also be performed after the aforementioned dyeing treatment step and before the extension treatment step in water. The aforementioned cross-linking treatment step is typically performed by immersing the PVA-based resin layer in a boric acid aqueous solution. By performing the cross-linking treatment step, the PVA-based resin layer can be given water resistance to prevent the PVA from being reduced in orientation when it is immersed in high-temperature water during subsequent water stretching. The boric acid concentration of the boric acid aqueous solution is preferably about 1 to 5 parts by weight relative to 100 parts by weight of water. Moreover, when performing the cross-linking treatment step, it is preferable to further blend the aforementioned iodide into the cross-linking bath. By blending the iodide, the elution of iodine adsorbed on the PVA-based resin layer can be suppressed. The blending amount of the aforementioned iodide is preferably about 1 to 5 parts by weight relative to 100 parts by weight of water. The liquid temperature of the cross-linking bath (boric acid aqueous solution) should be about 20~50℃.

>Water extension treatment steps> The above-mentioned underwater stretching treatment step is performed by immersing the laminated body in a stretching bath. Through the water stretching treatment step, it is possible to stretch at a temperature lower than the glass transition temperature of the thermoplastic resin base material or PVA-based resin layer (typically about 80°C), and it is possible to suppress the crystallization of the PVA-based resin layer. Perform high-magnification extension. The stretching method in the above-mentioned underwater stretching treatment step can be fixed-end stretching (such as using a tenter stretching machine to stretch), or free-end stretching (such as uniaxial stretching of the laminate through rollers with different peripheral speeds). method), and from the viewpoint of obtaining high optical properties, it is appropriate to extend the free end.

The above-mentioned aqueous stretching treatment step is preferably performed by immersing the laminate in a boric acid aqueous solution (boric acid aqueous stretching). By using a boric acid aqueous solution as a stretching bath, the PVA-based resin layer can be provided with rigidity capable of withstanding the tension during stretching and water resistance that is insoluble in water. The boric acid concentration of the boric acid aqueous solution is preferably 1 to 10 parts by weight relative to 100 parts by weight of water, and more preferably 2.5 to 6 parts by weight. Moreover, you may mix iodide into the said extension bath (boric acid aqueous solution). The liquid temperature of the extension bath should be around 40~85℃, and preferably around 60℃~75℃. The immersion time of the laminate in the extension bath is preferably about 15 seconds to 5 minutes.

The extension ratio of the aforementioned water extension treatment step is preferably about 1.5 times or more, and more preferably about 3 times or more.

In addition, the total extension ratio of the laminated body is preferably about 5 times or more, and more preferably about 5.5 times or more relative to the original length of the laminated body.

>Cleaning Processing Steps> It is advisable to perform a cleaning step after the aforementioned extending step in water. The aforementioned cleaning treatment step is typically performed by immersing the PVA-based resin layer in a potassium iodide aqueous solution.

Furthermore, each treatment bath in the aforementioned dyeing treatment step, the aforementioned water extension treatment step, the aforementioned insolubilization treatment step, the aforementioned cross-linking treatment step, and the aforementioned washing treatment step may also contain zinc salt, pH adjuster, and pH buffering agent. , other salt additives. Examples of the zinc salt include zinc halides such as zinc chloride and zinc iodide; inorganic zinc salts such as zinc sulfate and zinc acetate. Examples of the pH adjuster include strong acids such as hydrochloric acid, sulfuric acid, and nitric acid, or strong bases such as sodium hydroxide and potassium hydroxide. Examples of the pH buffering agent include carboxylic acids such as acetic acid, oxalic acid, and citric acid and their salts, or inorganic weak acids such as phosphoric acid and carbonic acid and their salts. Examples of the aforementioned other salts include chlorides such as sodium chloride, potassium chloride, and barium chloride; nitrates such as sodium nitrate and potassium nitrate; sulfates such as sodium sulfate and potassium sulfate; and alkali metal and alkaline earth metal salts. .

>Adhesive layer> The adhesive forming the adhesive layer of the present invention can be applied to various adhesives that can be used for polarizing films, such as rubber adhesives, acrylic adhesives, polysiloxane adhesives, urethane adhesives, and vinyl adhesives. Alkyl ether adhesives, polyvinyl alcohol adhesives, polyvinylpyrrolidone adhesives, polyacrylamide adhesives, cellulose adhesives, etc. Among them, acrylic adhesive is preferred. The acrylic adhesive contains an acrylic polymer as a base polymer, and examples thereof include those described in Japanese Patent Application Laid-Open No. 2017-75998.

The acrylic polymer in the aforesaid acrylic adhesive has a main skeleton of monomer units of (meth)acrylic acid alkyl ester. (Meth)acrylic acid alkyl ester can be suitably used (meth)acrylic acid alkyl ester having an alkyl carbon number of 1 to 20. The content of the (meth)acrylic acid alkyl ester is relative to the monomer component constituting the base polymer. The total amount is preferably 40% by weight or more, and more preferably 60% by weight or more. In addition, from the viewpoint of adjusting the adhesiveness of the adhesive, monomer units such as nitrogen-containing monomer units or hydroxyl-containing monomers may be included. In addition, in order to form a cross-linked structure in the adhesive layer, a cross-linking agent can also be used. For example, the cross-linking agent can use an isocyanate-based cross-linking agent, an epoxy-based cross-linking agent, Commonly used cross-linking agents include oxazoline-based cross-linking agents, aziridine-based cross-linking agents, carbodiimide-based cross-linking agents, and metal chelate-based cross-linking agents. The usage amount of the crosslinking agent is generally 10 parts by weight or less, and preferably 5 parts by weight or less relative to 100 parts by weight of the base polymer.

From the perspective of adjustable adhesion, silane coupling agents can also be added to the aforementioned adhesives; terpene-based tackifiers, styrene-based tackifiers, phenolic-based tackifiers, rosin-based tackifiers, and epoxy-based tackifiers Wait for the adhesive. In addition, from the viewpoint of improving light resistance, an ultraviolet absorber may be added. In addition to the ingredients listed above, plasticizers, softeners, anti-deterioration agents, fillers, colorants, antioxidants, surfactants, and antioxidants can also be used in the adhesive within the scope that does not impair the characteristics of the adhesive. Additives such as electrostatic agents.

The method of forming the adhesive layer may be, for example, the following method: applying the aforementioned adhesive to a peeled separation member, etc., drying it to form an adhesive layer, and then transferring it to a polarizing film, etc.; applying the aforementioned adhesive to a polarizing film, etc. A method of applying an adhesive to a polarizing film, etc., and drying it to form an adhesive layer. The thickness of the adhesive layer is not particularly limited, but is, for example, about 1 to 100 μm, and preferably about 2 to 50 μm.

>Adhesive layer> The adhesive forming the adhesive layer of the present invention can be applied to various adhesives that can be used for polarizing films, such as isocyanate adhesives, polyvinyl alcohol adhesives, gelatin adhesives, vinyl latex adhesives, water-based polyesters, etc. . These adhesives are usually used as adhesives composed of aqueous solutions (water-based adhesives) and contain 0.5 to 60% by weight of solid content. Among these, a polyvinyl alcohol-based adhesive is preferred, and a polyvinyl alcohol-based adhesive containing an acetyl acetyl group is more preferred.

The aforementioned water-based adhesive may also contain a cross-linking agent. The cross-linking agent can generally be used as a compound having at least two functional groups in one molecule that are reactive with components such as polymers constituting the adhesive. Examples of the cross-linking agent include alkylene diamines; isocyanates; and epoxies. ; Aldehydes; amines such as hydroxymethylurea, hydroxymethylmelamine, etc. - formaldehyde, etc. The blending amount of the cross-linking agent in the adhesive is generally about 10 to 60 parts by weight relative to 100 parts by weight of the polymer and other components constituting the adhesive.

In addition to the above, examples of the adhesive include active energy ray-curing adhesives such as ultraviolet curing adhesives and electron beam curing adhesives. Examples of the active energy ray curable adhesive include (meth)acrylate adhesives. Examples of the curable component of the (meth)acrylate-based adhesive include compounds having a (meth)acrylyl group and compounds having a vinyl group. Examples of compounds having a (meth)acrylyl group include chain alkyl (meth)acrylate having 1 to 20 carbon atoms, alicyclic alkyl (meth)acrylate, and polycyclic alkyl (meth)acrylic acid. Alkyl (meth)acrylates such as esters; (meth)acrylates containing hydroxyl groups; (meth)acrylates containing epoxy groups such as glycidyl (meth)acrylate, etc. The (meth)acrylate adhesive may contain hydroxyethyl(meth)acrylamide, N-hydroxymethyl(meth)acrylamide, or N-methoxymethyl(meth)acrylamide , N-ethoxymethyl(meth)acrylamide, (meth)acrylamide, (meth)acrylamide and other nitrogen-containing monomers. The (meth)acrylate-based adhesive may contain tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, and cyclic trimethylolpropane methyl as cross-linking components. Acetal acrylate, di Alkanediol diacrylate, EO modified diglyceryl tetraacrylate and other multi-functional monomers. In addition, a compound having an epoxy group or an oxetanyl group may be used as the cationic polymerization curable adhesive agent. The compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various generally known curable epoxy compounds can be used.

The aforementioned adhesive may also contain appropriate additives as required. Examples of the aforementioned additives include silane coupling agents such as silane coupling agents and titanium silane coupling agents, adhesion accelerators such as ethylene oxide, ultraviolet absorbers, anti-deterioration agents, dyes, processing aids, ion trapping agents, antioxidants, and adhesion-imparting agents. Agents, fillers, plasticizers, leveling agents, foaming inhibitors, antistatic agents, heat-resistant stabilizers, hydrolysis-resistant stabilizers, etc.

The adhesive may be applied to either the transparent protective film side (or the functional layer side to be described later) or the polarizing film side, or both. After lamination, a drying step is performed to form an adhesive layer consisting of a coating dry layer. After the aforementioned drying step, ultraviolet rays or electron rays can be irradiated as needed. The thickness of the aforementioned adhesive layer is not particularly limited. When using a water-based adhesive, etc., it is preferably about 30 to 5000 nm, and more preferably about 100 to 1000 nm. When using an ultraviolet curable adhesive, an electron beam curable adhesive, etc. , preferably about 0.1~100μm, preferably about 0.5~10μm.

When the aforementioned adhesive layer or adhesive layer contains the aforementioned hindered amine compound, from the viewpoint of suppressing the reduction in monomer transmittance caused by coloration of the polarizing film in a high-temperature environment, the content of the aforementioned hindered amine compound should be in the adhesive layer or adhesive layer. The content in the layer is preferably 1% by weight or more, more preferably 5% by weight or more, more preferably 10% by weight or more, more preferably 70% by weight or less, and still more preferably 50% by weight or less.

>Single-sided protective polarizing film and double-sided protective polarizing film> The single-sided protective polarizing film of the present invention is a transparent protective film laminated on at least one side of the polarizing film through the adhesive layer or the adhesive layer. Furthermore, the double-sided protective polarizing film of the present invention is one in which transparent protective films are laminated on both sides of the polarizing film through the adhesive layer or the adhesive layer.

The aforementioned transparent protective film is not particularly limited, and various transparent protective films that can be used for polarizing films can be used. The material constituting the transparent protective film may be a thermoplastic resin that is excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and the like. Examples of the thermoplastic resin include cellulose ester resins such as cellulose triacetate, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyether resins, and polyester resins. , polycarbonate resin, polyamide resin such as nylon or aromatic polyamide, polyimide resin, polyolefin resin such as polyethylene, polypropylene, ethylene-propylene copolymer, (methyl) Acrylic resins, cyclic or cyclic polyolefin resins having a norbornene structure (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. In addition, the aforementioned transparent protective film may be cured using a thermosetting resin such as (meth)acrylic, urethane, acrylic urethane, epoxy, polysilicone or the like, or an ultraviolet curing resin. layer. Among these, cellulose ester-based resins, polycarbonate-based resins, (meth)acrylic-based resins, cyclic polyolefin-based resins, and polyester-based resins are preferred.

The thickness of the above-mentioned transparent protective film can be appropriately determined, but generally from the viewpoint of strength, workability, thin-layer properties, etc., it is preferably about 1 to 500 μm, preferably about 1 to 300 μm, and more preferably about 5 to 100 μm. .

The aforementioned transparent protective film moves (resides) inside the image display device together with the moisture existing inside the image display device (moisture content present in the adhesive layer, adhesive layer, etc.) caused by the hindered amine compound and easily penetrates into the polarizing film. From a certain point of view, the moisture permeability should be above 50g/(m ² ·24h), preferably above 100g/(m ² ·24h), and above 200g/(m ² ·24h) even better. In addition, the moisture permeability can be By following the moisture permeability test (cup method) of JIS Z0208, a sample cut to a diameter of 60mm is placed in a moisture permeable cup containing about 15g of calcium chloride, and placed at a temperature of 40°C. It is calculated by measuring the weight increase of calcium chloride before and after leaving it in a thermostat with a humidity of 90%RH for 24 hours.

When the aforementioned transparent protective film is bonded to both sides of the aforementioned polarizing film, the transparent protective films on both sides may be the same or different from each other.

As the transparent protective film, a retardation plate having a front surface retardation of 40 nm or more and/or a thickness direction retardation of 80 nm or more can be used. 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 plate is used as the transparent protective film, the retardation plate can also function as a transparent protective film, so that the thickness can be reduced.

Examples of the retardation plate include a birefringent film obtained by uniaxially or biaxially stretching a polymer material, an alignment film of a liquid crystal polymer, an alignment layer using a film to support the liquid crystal polymer, and the like. The thickness of the phase difference plate is not particularly limited, but is generally around 20~150μm. In addition, the above-mentioned phase plate can also be used by laminating a transparent protective film without phase difference.

The aforementioned transparent protective film may also contain any appropriate UV absorbers, antioxidants, lubricants, plasticizers, release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, colorants, etc. of additives. Especially when the aforementioned transparent protective film contains an ultraviolet absorber, the light resistance of the polarizing film can be improved.

The surface of the aforementioned transparent protective film that is not attached to the polarizing film can be provided with functional layers such as a hard coating layer, an anti-reflective layer, an anti-adhesive 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-adhesion layer, diffusion layer or anti-glare layer may be provided separately from the protective film.

The aforementioned polarizing film and the aforementioned transparent protective film, or the aforementioned polarizing film and the aforementioned functional layer are generally bonded together through the aforementioned adhesive layer or the aforementioned adhesive layer.

The transparent protective film and the polarizing film or the polarizing film and the functional layer may be laminated via an intermediary layer such as a surface modification treatment layer, an easy adhesive layer, a barrier layer, or a refractive index adjustment layer.

Examples of the surface modification treatment to form the surface modification layer include corona treatment, plasma treatment, primer treatment, saponification treatment, and the like.

Examples of the easy-adhesive agent that forms the easy-adhesive layer include forming materials containing various resins having the following skeletons: polyester skeleton, polyether skeleton, polycarbonate skeleton, polyurethane skeleton, polysiloxane, polyester skeleton, etc. Amide skeleton, polyimide skeleton, polyvinyl alcohol skeleton, etc. The easily adhesive layer is usually provided on the protective film in advance, and the easily adhesive layer side of the protective film is laminated with the polarizing film through the adhesive layer or the adhesive layer.

The barrier layer has a function of preventing impurities such as oligomers and ions eluted from a transparent protective film or the like from moving (invading) into the polarizing film. The barrier layer may be a layer that is transparent and can prevent impurities eluted from a transparent protective film or the like. Examples of materials that form the barrier layer include urethane prepolymer-based forming materials and cyanoacrylate-based forming materials. , epoxy forming materials, etc.

The refractive index adjustment layer is a layer provided to suppress a decrease in transmittance due to reflection between layers having different refractive indexes, such as the transparent protective film and the polarizing film. Examples of the refractive index adjusting material forming the refractive index adjusting layer include forming agents containing various resins and additives such as silica-based, acrylic-based, acrylic-styrene-based, and melamine-based resins.

From the viewpoint of suppressing the reduction in monomer transmittance caused by coloration of the polarizing film in a high-temperature environment, the polarizing film of the present invention satisfies the conditions shown in the general formula (1): General formula (1): In the formula (1), A layer is bonded to a glass plate, and the polarizing film is a transparent protective film bonded to at least one side of the polarizing film through the adhesive layer). In addition, the aforementioned X (% by weight) is preferably 0.02 or more, and more preferably 0.05 or more.

>Laminated polarizing film> The laminated polarizing film (optical laminated body) of the present invention has an optical layer bonded to at least one side of the single-sided protective polarizing film or the double-sided protective polarizing film through the adhesive layer or the adhesive layer.

The aforementioned optical layer is not particularly limited. For example, one or more layers can be used, such as reflective plates and semi-transmissive plates, phase difference plates (including 1/2 and 1/4 wavelength plates), viewing angle compensation films, etc., which can be used to form liquid crystals. Optical layer of display devices, etc. Examples of the laminated polarizing film include, for example, a reflective polarizing film or a semi-transmitting polarizing film in which a reflective plate or a semi-transmissive reflective plate is laminated on the polarizing film, and a retardation plate in which a retardation plate is laminated on the polarizing film. An elliptical polarizing film or a circular polarizing film, a wide viewing angle polarizing film formed by laminating a viewing angle compensation film on the aforementioned polarizing film, or a polarizing film formed by laminating a brightness enhancement film on the aforementioned polarizing film.

The aforementioned single-sided protective polarizing film, double-sided protective polarizing film or the aforementioned laminated polarizing film can also be provided with the aforementioned adhesive layer or the aforementioned adhesive layer on one or both sides in advance to adhere to image display units such as liquid crystal units or organic EL elements. Other components such as a front transparent plate on the viewing side or a front transparent component such as a touch panel. As mentioned above, those with an adhesive layer on at least one side of the aforementioned polarizing film or the aforementioned laminated polarizing film are called single-sided protective polarizing films with an adhesive layer, double-sided protective polarizing films with an adhesive layer, or adhesives. A layer of laminated polarizing film.

In order to prevent the aforementioned adhesive layer or the exposed surface of the aforementioned adhesive layer from being contaminated, it is advisable to temporarily attach and cover it with a separator before it is actually used. This can prevent the adhesive layer or the aforementioned adhesive layer from being contaminated under normal handling conditions. As the aforementioned separator, for example, suitable thin sheets made of plastic films, rubber sheets, paper, cloth, non-woven fabrics, mesh, foam sheets or metal foils, and laminates of these, etc., can be used. Or long-chain alkyl-based, fluorine-based or molybdenum sulfide and other appropriate stripping agents for coating treatment, etc.

>Front transparent component> The front transparent component of the present invention is a front transparent component arranged on the viewing side of the image display unit. Examples of the front transparent member include a front transparent plate (window layer), a front touch panel, and the like. As the front transparent plate, a front transparent plate having appropriate mechanical strength and thickness can be used. As the transparent plate, for example, a transparent resin plate such as an acrylic resin or a polycarbonate resin, a glass plate, or the like can be used. The aforementioned touch panel can use various touch panels such as resistive film type, capacitive type, optical type, ultrasonic type, etc., or a glass plate or a transparent resin plate with touch sensing function. When a capacitive touch panel is used as the front transparent member, it is preferable to provide a front transparent plate made of glass or a transparent resin plate closer to the viewing side than the touch panel.

>Image display unit> Examples of the image display unit of the present invention include a liquid crystal unit or an organic EL unit. The liquid crystal cell may be a reflective liquid crystal cell that utilizes external light, a transmissive liquid crystal cell that utilizes light from a light source such as a backlight, or a transflective liquid crystal cell that utilizes both external light and light from a light source. Any of them. When the aforementioned liquid crystal unit uses light from a light source, the image display device (liquid crystal display device) will also be equipped with a polarizing film on the side opposite to the viewing side of the image display unit (liquid crystal unit), and will be equipped with a light source. The polarizing film on the light source side and the liquid crystal unit should be bonded through an appropriate adhesive layer. The driving mode of the liquid crystal cell can be any type such as VA mode, IPS mode, TN mode, STN mode or bend orientation (π type).

As the organic EL unit, for example, a transparent electrode, an organic light-emitting layer, and a metal electrode are sequentially stacked on a transparent substrate to form a light-emitting body (organic electroluminescent body). The organic light-emitting layer is a laminate of various organic thin films. For example, it can be composed of the following layers: a laminate of a hole injection layer made of a triphenylamine derivative and a light-emitting layer made of a fluorescent organic solid such as anthracene; A laminate of these luminescent layers and an electron injection layer composed of a perylene derivative or the like; or a laminated body of a hole injection layer, a luminescent layer and an electron injection layer, etc. Example

The following examples are given to illustrate the present invention in more detail, but the present invention is not limited only to these examples.

>Example 1>>Production of polarizing film> Prepare a polyvinyl alcohol film with an average degree of polymerization of 2,400, a saponification degree of 99.9 mol%, and a thickness of 45 μm. The polyvinyl alcohol film is immersed in a swelling bath (water bath) at 20°C for 30 seconds between rollers with different peripheral speed ratios to swell, and is extended 2.2 times in the conveying direction (swelling step), and then, at 30°C, In a dyeing bath (an iodine aqueous solution obtained by mixing iodine and potassium iodide at a weight ratio of 1:7 with respect to 100 parts by weight of water), the concentration is adjusted so that the iodine concentration of the finally obtained polarizing film becomes 4.47% by weight, while being immersed in Dyeing is performed for 30 seconds, and the polyvinyl alcohol film is stretched 3.3 times in the conveyance direction based on the original polyvinyl alcohol film (polyvinyl alcohol film that has not been stretched in the conveyance direction at all) (dyeing step). Next, the dyed polyvinyl alcohol film was immersed in a cross-linking bath at 40°C (an aqueous solution with a boric acid concentration of 3.0% by weight and a potassium iodide concentration of 3.0% by weight) for 28 seconds, and the original polyvinyl alcohol film was used as the basis. Extend to 3.6 times along the conveying direction (cross-linking step). The obtained polyvinyl alcohol film was then immersed in a stretching bath at 61° C. (an aqueous solution with a boric acid concentration of 4.0% by weight and a potassium iodide concentration of 5.0% by weight) for 60 seconds, and was extended along the conveying direction based on the original polyvinyl alcohol film. 6.0 times (extension step), then immersed in a 35°C cleaning bath (an aqueous solution with a potassium iodide concentration of 2.0% by weight and a hindered amine compound represented by the following general formula (6) with a concentration of 0.4% by weight) for 10 seconds. (Wash step). The washed polyvinyl alcohol film was dried at 40° C. for 30 seconds to prepare a polarizing film. The hindered amine content in the polarizing film determined by the following measurement method was 0.28% by weight, and the thickness of the polarizing film was 18 μm. In addition, the hindered amine compound represented by the following general formula (6) is a compound that dissolves 1 part by weight or more with respect to 100 parts by weight of water at 25°C. [Chemical formula 6] …(6)

[Method for determination of hindered amine compound content (% by weight) in polarizing films] Approximately 20 mg of the polarizing film was collected and quantified, heated and dissolved in 1 mL of water, and diluted with 4.5 mL of methanol. The resulting extract was filtered with a membrane filter, and the filtrate was measured using HPLC (ACQUITY UPLC H-class Bio manufactured by Waters Corporation). Concentration of hindered amine compounds.

[Method for determination of iodine content (% by weight) in polarizing films] For the polarizing film, an X-ray fluorescence analyzer (manufactured by Rigaku Co., Ltd., trade name "ZSX-PRIMUS IV", measuring diameter: ψ20 mm) was used to determine the iodine concentration (% by weight) using the following formula. Iodine concentration (wt%) = 14.474 × (fluorescence Obtained from the measurement curve.

>Production of polarizing film> The following aqueous solution is used as the adhesive: polyvinyl alcohol resin containing acetyl acetate group in a weight ratio of 3:1 (average degree of polymerization 1,200, degree of saponification 98.5 mol%, degree of acetyl acetylation) 5 mol%) and hydroxymethylmelamine. Using this adhesive, a 47 μm thick triacetyl cellulose film (moisture vapor permeability 342 g/(m ² 24 h), manufactured by Konica Minolta, trade name "KC4UYW") with a hard coat layer was used as a transparent protective film using a roll laminator. After being bonded to both sides of the polarizing film obtained above, it is then heated and dried in an oven (temperature: 60°C, time: 4 minutes) to produce a polarizing film in which transparent protective films are bonded to both sides of the polarizing film. The single transmittance of the polarizing film is 37.4%.

>Preparation of acrylic adhesive> The monomer mixture containing 99 parts by weight of butyl acrylate and 1 part by weight of 4-hydroxybutyl acrylate was fed into a 4-neck flask equipped with a stirring blade, a thermometer, a nitrogen introduction pipe, and a cooler. And relative to 100 parts by weight of the aforementioned monomer mixture (solid content), 0.1 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator and 100 parts by weight of ethyl acetate were fed together while slowly stirring. After nitrogen gas was introduced to perform nitrogen substitution, the liquid temperature in the flask was maintained at approximately 55° C., and a polymerization reaction was performed for 8 hours to prepare a solution of an acrylic polymer with a weight average molecular weight (Mw) of 1.8 million. Thereafter, an isocyanate crosslinking agent (manufactured by Tosoh Corporation, trade name "TAKENATE D110N", trimethylolpropane/diisocyanate crosslinking agent) was blended with 100 parts by weight of the solid content of the obtained acrylic polymer solution. 0.02 parts by weight of stubble ester adduct) and 0.2 parts by weight of silane coupling agent (trade name "X-41-1056" manufactured by Shin-Etsu Chemical Industry Co., Ltd.) to prepare a solution of an acrylic adhesive composition. Next, the solution of the acrylic adhesive composition obtained above was applied to the polyethylene terephthalate film treated with the polysiloxane release agent so that the thickness of the dried adhesive layer became 20 μm. (Mitsubishi Chemical polyester film, trade name "MRF38", release film) on one side and dried at 90°C for 1 minute to form an adhesive layer on the surface of the release film. Then, the adhesive layer formed on the release film is transferred to one side of the polarizing film produced above, thereby producing a polarizing film with an adhesive layer.

>Production of analog image display device (laminated body)> The polarizing film with the adhesive layer obtained above is cut into a size of 40×40mm in such a way that the absorption axis of the polarizing film is the long side, and the glass plate (simulated image display unit) is laminated through the adhesive layer, and then the polarizing film is The other side is bonded to another glass plate (simulated front transparent member) through a 200 μm thick acrylic monomer-free adhesive (manufactured by Nitto Denko Co., Ltd., trade name "LUCIACS CS9868") to create an analog image display device ( laminated body).

[Evaluation of single-piece transmittance in high-temperature environment] The simulated image display device (laminated body) obtained above was placed in a hot-air oven at a temperature of 105°C for 48 hours, and the single-piece transmittance (ΔTs) before and after being put in (heated) was measured. ). The single transmittance was measured using a spectrophotometer (manufactured by Murakami Color Technology Research Institute Co., Ltd., product name "DOT-3") and evaluated based on the following standards. The single transmittance is the Y value obtained by visual sensitivity compensation based on the 2-degree field of view (C light source) of JIS Z 8701-1982. In addition, the measurement wavelength is 380~700nm (every 10nm). The results are listed in Table 1. ΔTs (%) = Ts ₄₈ - Ts ₀ Here, Ts ₀ is the single transmittance of the simulated image display device (laminated body) before heating, and Ts ₄₈ is the transmittance of the simulated image display device (laminated body) after heating for 48 hours. Single unit transmittance. ○: 5≧ΔTs(%)≧0 ×: ΔTs(%)>5, or ΔTs(%)>0

The aforementioned ΔTs(%) is preferably 5≧ΔTs(%)≧0, and 4≧ΔTs(%)≧0 is more preferred.

[Measurement of the content of hindered amine compounds contained in polarizing films under high temperature environments] The simulated image display device (laminated body) obtained above was placed in a hot air oven at a temperature of 105°C for 24 hours, and the content of the hindered amine compound contained in the polarizing film after being put in (heated) was determined by the following method. Immerse the heated analog image display device in about 1000 mL of methylene chloride or toluene solution for more than 3 days to dissolve the protective film. After taking out the polarizing film, the polarizing film is about 40 mg. After washing the aforementioned polarizing film with pure methylene chloride or toluene, take and quantify about 1 mg of the polarizing film, heat and dissolve it in 0.5 mL of water, dilute it with 1 mL of methanol, and then filter the obtained extract with a membrane filter, and use LCMS ( The concentration of the hindered amine compound in the filtrate was measured using UltiMate3000/LTQ orbitrap XL (manufactured by Thermo Fisher Scientific).

>Example 2> >Production of polarizing films, polarizing films, and analog image display devices (laminated bodies)> When making the polarizing film, the hindered amine compound represented by the general formula (6) was not added to the cleaning bath, and when making the polarizing film, the two adhesives used were added in a weight ratio of 4:3. Except for the hindered amine compound represented by the formula (6) and the polyvinyl alcohol resin, the same operation as in Example 1 was carried out to produce a polarizing film, a polarizing film and an analog image display device (laminated body). The single transmittance of the polarizing film is 39.7%.

>Example 3>>Preparation of polarizing film, polarizing film, and analog image display device (laminated body)> When producing the polarizing film, the hindered amine compound represented by the general formula (6) was not added to the cleaning bath, and during the production When making a polarizing film, add the hindered amine compound represented by the general formula (7) and the polyvinyl alcohol resin to the two adhesives in a weight ratio of 4:3, and so as not to affect the hardening reaction of the adhesive. Potassium hydroxide was added to the hindered amine-based compound so that the molar ratio became 1:1 to adjust the pH (neutralize). Except for this, the same operations were performed as in Example 1 to produce a polarizing film, a polarizing film and a simulated image. Display device (laminated body). The single transmittance of the polarizing film is 40.0%. Moreover, the hindered amine compound represented by the following general formula (7) is a compound which dissolves 1 part by weight or more with respect to 100 parts by weight of water of 25 degreeC. [Chemical Formula 7] …(7)

>Example 4>>Preparation of polarizing film, polarizing film, and analog image display device (laminated body)> When producing the polarizing film, the hindered amine compound represented by the general formula (6) was not added to the cleaning bath, and during the production When making a polarizing film, add the hindered amine compound represented by the general formula (8) and the polyvinyl alcohol resin to the two adhesives in a weight ratio of 4:3, and so as not to affect the hardening reaction of the adhesive. The pH of the hindered amine compound was adjusted by adding hydrochloric acid so that the molar ratio was 1:1 (neutralization). Except for this, the same operations were performed as in Example 1 to produce a polarizing film, a polarizing film, and an analog image display device. (laminated body). The single transmittance of the polarizing film is 39.9%. Moreover, the hindered amine compound represented by the following general formula (8) is a compound which dissolves 1 part by weight or more with respect to 100 parts by weight of water of 25 degreeC. [Chemical formula 8] …(8)

>Example 5> >Production of polarizing films, polarizing films, and analog image display devices (laminated bodies)> When making the polarizing film, the hindered amine compound represented by the general formula (6) was not added to the cleaning bath, and when making the polarizing film, the two adhesives used were used in a weight ratio of 7:2:1. Aqueous solutions of acetoacetyl-containing polyvinyl alcohol resin, methylol melamine and a hindered amine compound represented by the general formula (6) were used in the same manner as in Example 1 to prepare a polarizing film and a polarizing film. and analog image display devices (laminated bodies). The single transmittance of the polarizing film is 39.7%.

>Example 6>>Preparation of polarizing film, polarizing film, and analog image display device (laminated body)> When producing the polarizing film, the two adhesives used were mixed with 40 wt. of N-hydroxyethylacrylamide (HEAA) An adhesive was prepared by mixing 60 parts by weight of acrylic mofelin (ACMO) and 3 parts by weight of photoinitiator "IRGACURE 819" (manufactured by BASF) so that the thickness of the adhesive layer after hardening would be 1.0 μm. The method is coated on the polarizing film, and then irradiated with ultraviolet rays as active energy rays to harden the adhesive to produce a polarizing film. In addition, the same operations are performed as in Example 1 to produce a polarizing film, a polarizing film and a simulated image. Display device (laminated body). 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), the illuminance of ultraviolet rays was measured using the Sola-Check system manufactured by Solatell.

>Example 7> >Production of polarizing films, polarizing films, and analog image display devices (laminated bodies)> The thermoplastic resin base material is a long amorphous isophthalic acid copolymerized polyethylene terephthalate film (thickness: 100 μm) with a water absorption rate of 0.75% and a Tg of approximately 75°C. And corona treatment is applied to one side of the resin substrate. A PVA system made by mixing polyvinyl alcohol (degree of polymerization 4200, saponification degree 99.2 mol%) and acetyl-acetyl modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFIMER Z410") at a ratio of 9:1 To 100 parts by weight of the resin, 13 parts by weight of potassium iodide was added to prepare a PVA aqueous solution (coating liquid). The above-mentioned PVA aqueous solution was applied to the corona-treated surface of the resin base material and dried at 60° C. to form a PVA-based resin layer with a thickness of 13 μm, thereby producing a laminate. The obtained laminate was uniaxially extended at the free end 2.4 times in the longitudinal direction (long side direction) between rollers with different circumferential speeds in an oven at 130°C (air-assisted stretching treatment). Next, the laminated body was immersed in an insolubilization bath (a boric acid aqueous solution with a boric acid concentration of 4.0% by weight) having a liquid temperature of 40° C. for 30 seconds (insolubilization treatment). Next, while adjusting the concentration in a dyeing bath (an iodine aqueous solution obtained by mixing iodine and potassium iodide at a weight ratio of 1:7 with respect to 100 parts by weight of water) with a liquid temperature of 30° C., the polarizing film finally produced has The iodine concentration was set to 8.11% and immersed in it for 60 seconds (dyeing treatment). Then, it was immersed in a cross-linking bath (an aqueous solution with a potassium iodide concentration of 3.0% by weight and a boric acid concentration of 5.0% by weight) with a liquid temperature of 40°C for 30 seconds (cross-linking treatment). Then, while the laminated body was immersed in a boric acid aqueous solution with a liquid temperature of 70° C. (boric acid concentration 4.0% by weight), it was uniaxially stretched in the longitudinal direction (longitudinal direction) between rollers with different circumferential speeds so that the total stretching ratio was Up to 5.5 times (extension treatment in water). Thereafter, the laminated body was immersed in a cleaning bath (potassium iodide concentration: 3% by weight) with a liquid temperature of 30° C. (cleaning treatment). Thereafter, it was dried in an oven maintained at 90° C. while keeping the surface temperature in contact with a SUS heated roller kept at 75° C. for about 2 seconds (drying shrinkage treatment). Through the above procedures, a polarizing film with a thickness of 5 μm was formed on the resin substrate.

After that, the following aqueous solution was used as the adhesive: polyvinyl alcohol resin containing acetyl acetate group in a weight ratio of 3:1 (average degree of polymerization 1,200, degree of saponification 98.5 mol%, degree of acetate acetyl group 5 mol) %) and hydroxymethylmelamine. Use this adhesive to use a roller laminating machine to make a 30 μm thick transparent protective film (manufactured by Nippon Shokubai, moisture permeability 125g/ (m ²・24h)) is bonded to the surface of the polarizing film obtained above which is opposite to the resin base material. Then, the resin base material is peeled off, and an acrylic adhesive layer containing a hindered amine compound is transferred to the peeled surface to produce a polarizing film with an adhesive layer attached. An acrylic adhesive containing a hindered amine compound is prepared by blending 20 parts by weight of the general formula (6) as a hindered amine compound and an isocyanate cross-linking agent (Tosoh ( Made by Tosoh Co., Ltd., trade name "TAKENATE D110N", trimethylolpropane/styl diisocyanate adduct) 0.02 parts by weight, silane coupling agent (manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "X-41- 1056″)0.2 parts by weight.

The acrylic monomer-free adhesive described in Example 1 is bonded to the transparent protective film surface of the polarizing film with the adhesive layer, and the glass plate is bonded through the adhesive layers on both sides to produce an analog image display device (laminated body) ).

>Comparative Example 1> >Production of polarizing films, polarizing films, and analog image display devices (laminated bodies)> When making the polarizing film, the hindered amine compound represented by the general formula (6) was not added to the cleaning bath. In addition, the same operation as in Example 1 was performed to produce a polarizing film, a polarizing film and an analog image display device ( laminated body). The hindered amine content of the obtained polarizing film was 0% by weight, and the thickness was 18 μm. The single transmittance of the polarizing film is 39.6%.

>Comparative example 2> >Production of polarizing films, polarizing films, and analog image display devices (laminated bodies)> When making the polarizing film, no hindered amine compound was added to the acrylic adhesive. In addition, the same operation as in Example 7 was performed to produce a polarizing film, a polarizing film and an analog image display device (laminated body).

>Comparative Example 3>>Preparation of polarizing film, polarizing film, and analog image display device (laminated body)> When producing the polarizing film, the hindered amine compound represented by the general formula (6) was not added to the cleaning bath, and the adhesive It is a mixture of 35 parts by weight of N-hydroxyethylacrylamide (HEAA), 50 parts by weight of acrylomorphine (ACMO), 5 parts by weight of photoinitiator "IRGACURE 819" (manufactured by BASF) and the general formula (9 ) 10 parts by weight of the compound (trade name "ADK STAB LA-52", manufactured by ADEKA Co., Ltd.), and apply it on the polarizing film so that the thickness of the adhesive layer after hardening becomes 1.0 μm, and then use ultraviolet rays as the active Energy rays were irradiated to harden the adhesive to produce a polarizing film. Except for this, the same operations were performed as in Example 1 to produce a polarizing film, a polarizing film and a simulated image display device (laminated body). 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), the illuminance of ultraviolet rays was measured using the Sola-Check system manufactured by Solatell. In addition, the hindered amine compound represented by the following general formula (9) is a compound that does not dissolve 1 part by weight or more with respect to 100 parts by weight of water at 25°C. [Chemical formula 9] …(9)

Using the simulated image display devices (laminated bodies) of the above-obtained Examples and Comparative Examples, the above-mentioned [Evaluation of Monomeric Transmittance under High-temperature Environment] and [Measurement of Hindered Amine-based Compounds Contained in Polarizing Films under High-temperature Environment were performed. content]. The results are listed in Table 1.

[Table 1]

10:Polarizing film 11:Polarizing film 12, 13: Transparent protective film 20, 30, 40, 50: adhesive layer or adhesive layer 80: Front transparent component 90:Image display unit 100:Image display device 101: Single-sided protective polarizing film 102: Double-sided protective polarizing film

FIG. 1 is a schematic cross-sectional view showing one form of the image display device. Figure 2 is a schematic cross-sectional view showing one form of a single-sided protective polarizing film. Figure 3 is a schematic cross-sectional view showing one form of the double-sided protective polarizing film.

10:Polarizing film

20, 30: Adhesive layer or adhesive layer

80: Front transparent component

90:Image display unit

100:Image display device

Claims (6)

An image display device is provided with a front transparent member, a polarizing film and an image display unit in sequence through an adhesive layer or adhesive layer. The image display device is characterized by: The aforementioned polarizing film has a polarizing film formed by adsorbing and orienting iodine to a polyvinyl alcohol-based film; At least one of the aforementioned polarizing film, the aforementioned adhesive layer and the aforementioned adhesive layer contains a hindered amine compound; The aforementioned hindered amine compound is a water-soluble hindered amine compound that can dissolve more than 1 part by weight relative to 100 parts by weight of water at 25°C; The aforementioned polarizing film satisfies the conditions shown in general formula (1): General formula (1): X(weight%)＞0.01 (In the general formula (1), The adhesive layer is bonded to a glass plate, and the polarizing film is a transparent protective film bonded to at least one side of the polarizing film through the adhesive layer). The image display device of claim 1, wherein the hindered amine compound is a compound having an organic group represented by general formula (1): [Chemical Formula 1] ...(1) (In the general formula (1), R ¹ represents an oxygen radical, a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 30 carbon atoms, a hydroxyalkyl group, a hydroxyalkoxy group or an alkoxy group, and R ² R ⁵ independently represents a hydrogen atom or an alkyl group with 1 to 10 carbon atoms, and n represents 0 or 1). The image display device of claim 1, wherein the hindered amine compound is one or more compounds selected from the group consisting of the following compounds: Compound represented by the general formula (2): [Chemical Formula 2] ...(2) (In the general formula (2), R ¹ to R ⁵ and n are the same as above, R ⁶ represents a hydrogen atom or an alkyl group with 1 to 10 carbon atoms, a hydroxyl group or an aryl group, and n represents 0 Or 1); Compound represented by general formula (3): [Chemical formula 3] ...(3) (In the general formula (3), R ¹ to R ⁵ and n are the same as above, R ⁷ and R ⁸ independently represent a hydrogen atom or an alkyl group with 1 to 10 carbon atoms, an acyl group or an aryl group. ); Compound represented by general formula (4): [Chemical formula 4] ...(4) (In the general formula (4), R ¹ to R ⁵ and n are the same as above, and R ⁹ to R ¹¹ independently represent a hydrogen atom or an alkyl group with 1 to 10 carbon atoms, a hydroxyl group, an amine group, Alkoxy group, hydroxyl group or aryl group); and the compound represented by the general formula (5): [Chemical Formula 5] ...(5) (In the general formula (5), R ¹ to R ⁵ and n are the same as above, R ¹² represents a hydrogen atom or an alkyl group with 1 to 10 carbon atoms, an amino group, an alkoxy group, a hydroxyl group or an extension group. Aryl). The image display device of claim 1, wherein the polarizing film is a single-sided protective polarizing film bonded with a transparent protective film on at least one side of the polarizing film through the adhesive layer or the adhesive layer. The image display device of claim 1, wherein the polarizing film is a double-sided protective polarizing film laminated with a transparent protective film through the adhesive layer or the adhesive layer on both sides of the polarizing film. The image display device of claim 4 or 5 is a laminated polarizing film in which an optical layer is bonded to at least one side of the single-sided protective polarizing film or the double-sided protective polarizing film through the adhesive layer or the adhesive layer.