KR20190116279A - Image display apparatus and manufacturing method of the image display apparatus - Google Patents

Abstract

There is provided an image display apparatus which can maintain excellent optical characteristics even in a humidified environment, and is prevented from losing color. The image display apparatus of this invention is provided with the display cell 10, the polarizing plate 20 arrange | positioned at the at least one side of the display cell 10, and the sealing part 30 which covers the peripheral end surface of the polarizing plate 20. FIG. do. The polarizing plate 20 contains the polarizing film 21 comprised from the polyvinyl alcohol-type resin film containing iodine, and the water vapor transmission rate of the sealing part 30 is 300 g / m <2> / 24hr or less. In one embodiment, the amount of color fading after holding for 120 hours in an 85 degreeC and 85% RH environment of an image display apparatus is 100 micrometers or less.

Description

Image display apparatus and manufacturing method of the image display apparatus

The present invention relates to an image display device and a manufacturing method of the image display device.

In an image display device (for example, a liquid crystal display device, an organic EL display device, and a quantum dot display device), due to its image forming method, a polarizing plate is disposed on at least one side of a display cell in many cases. However, the polarizing plate has the problem of durability that the optical characteristic of the polarizing film which substantially dominates the optical characteristic of the polarizing plate is lowered under a humidified environment. More specifically, in the polarizing film, the polarization performance of the end part is lost in a humidified environment, and as a result, a phenomenon called color fading may occur in the image display device.

Patent Document 1: Japanese Unexamined Patent Publication No. 2000-338329

This invention is made | formed in order to solve the said subject, The main objective is to provide the image display apparatus which can maintain the outstanding optical characteristic in a humidified environment, and the color fall prevention, and the simple manufacturing method of such an image display apparatus. .

 The image display apparatus of this invention is equipped with a display cell, the polarizing plate arrange | positioned at at least one side of this display cell, and the sealing part which covers the peripheral end surface of this polarizing plate. This polarizing plate contains the polarizing film comprised from the polyvinyl alcohol-type resin film containing iodine, and the moisture permeability of the said sealing part is 300 g / m <2> / 24hr or less.

In one embodiment, the said sealing part covers the front surface of the side opposite to the said display cell of the said polarizing plate, and the front surface of the said peripheral cross section.

In one embodiment, the thickness of the said sealing part is 10 micrometers-100 micrometers.

In one embodiment, the said sealing part is comprised by the adhesive agent composition. For example, the sealing portion is composed of a rubber-based pressure-sensitive adhesive.

In one embodiment, the said image display apparatus further includes the cover glass arrange | positioned at the opposite side to the said display cell of the said polarizing plate.

In one embodiment, the said image display apparatus is 100 micrometers or less in color fallout after hold | maintaining for 120 hours in 85 degreeC and 85% RH environment.

According to another situation of this invention, the manufacturing method of an image display apparatus is provided. This manufacturing method includes disposing a polarizing plate on one side of the display cell, and forming a sealing portion so as to cover a peripheral end face of the polarizing plate. This polarizing plate contains the polarizing film comprised from the polyvinyl alcohol-type resin film containing iodine, and the water vapor transmission rate of the said sealing part is 300 g / m <2> / 24hr or less.

In one embodiment, the said manufacturing method includes forming a sealing part so that the front surface of the surface opposite to the said display cell of the said polarizing plate, and the front surface of the said peripheral cross section may be covered.

In one embodiment, the said manufacturing method includes forming a sealing part by arrange | positioning the sheet | seat which consists of an adhesive agent composition.

In one embodiment, the size of the sheet is larger than that of the polarizing plate, and the manufacturing method forms a sealing portion by arranging the sheet so as to cover the front surface of the side opposite to the display cell of the polarizing plate and the front surface of the peripheral cross section. It includes.

In one embodiment, the said manufacturing method further includes arrange | positioning a cover glass on the opposite side to the said display cell of the said polarizing plate.

According to the present invention, by forming a sealing part having a predetermined moisture permeability on the outer circumferential end face of the polarizing plate, excellent optical properties can be maintained even in a humidified environment, and an image display device in which color fading can be prevented can be realized. Moreover, according to this invention, the simple manufacturing method of such an image display apparatus can be implement | achieved. In one embodiment, the said manufacturing method consists of an adhesive agent composition, and arrange | positions the sheet so that the front surface of the opposite side to the display cell and the front surface of the said peripheral cross section may be covered using the sheet | seat which has a magnitude | size larger than a polarizing plate. Forming a seal. According to such an embodiment, even in a humid environment, excellent optical characteristics can be maintained, and an image display device in which color fading is prevented can be manufactured very simply.

1 is a schematic partial sectional view of an image display device according to one embodiment of the present invention.
2 is a schematic diagram for explaining the calculation of the amount of color loss.
3 is a schematic view for explaining an example of a method of manufacturing the image display device of the present invention.
It is an image which shows the amount of color fading after the humidification test of the liquid crystal display replacement product corresponding to Example 1. FIG.
It is an image which shows the amount of color fading after the humidification test of the liquid crystal display replacement product corresponding to the comparative example 1. FIG.

EMBODIMENT OF THE INVENTION Hereinafter, although embodiment of this invention is described, this invention is not limited to these embodiment.

 A. Overall Configuration of the Image Display Device

The present invention can be applied to an image display device having a polarizing plate on at least one side of a display cell. As a specific example of such an image display apparatus, a liquid crystal display device, an organic electroluminescent (EL) display device, and a quantum dot display device are mentioned. EMBODIMENT OF THE INVENTION Hereinafter, embodiment which applied this invention to the visual recognition side part of a liquid crystal display device is demonstrated as an example. It is apparent to those skilled in the art that the present invention can be applied to the back side portion of the liquid crystal display device, the organic EL display device, and the quantum dot display device in the same manner as the visual side of the liquid crystal display device.

1 is a schematic partial sectional view of an image display device according to one embodiment of the present invention, and in more detail, a schematic sectional view of a visible side portion of a liquid crystal display device. The liquid crystal display device 100 of FIG. 1 includes a liquid crystal cell 10, a polarizing plate 20 disposed on the viewing side of the liquid crystal cell 10, and a sealing unit 30 covering a peripheral end surface of the polarizing plate 20. do. The polarizing plate 20 includes a polarizing film 21. In the example of illustration, although the protective film 22 is arrange | positioned at the one side (opposite side of a liquid crystal cell) of the polarizing film 21, a protective film may be arrange | positioned at the liquid crystal cell side of a polarizing film according to the objective, etc., and may be arrange | positioned at both sides. . In practice, the pressure-sensitive adhesive layer 50 is formed as the outermost layer on the liquid crystal cell 10 side of the polarizing plate 20, and the polarizing plate 20 is bonded to the liquid crystal cell 10 via the pressure-sensitive adhesive layer 50. . The liquid crystal display device 100 further includes a cover glass 40 disposed on the viewing side (the side opposite to the liquid crystal cell) of the polarizing plate 20. When the cover glass is formed, the protective film 22 may be omitted. Since the back side parts of the liquid crystal cell and the liquid crystal display device can be employed in the art, a detailed description thereof will be omitted.

In embodiment of this invention, the polarizing film 21 is comprised from the polyvinyl alcohol-type resin (henceforth "PVA-type resin") film containing iodine. When a polarizing film contains iodine, the effect of forming a sealing part becomes remarkable. The thickness of a polarizing film is typically 8 micrometers or less. When the polarizing film contains iodine and its thickness is so thin, the iodine density in the polarizing film becomes high and the stability of iodine due to humidification tends to be lowered, so that the effect of forming the sealing portion becomes more remarkable.

Moreover, in embodiment of this invention, the water vapor transmission rate of a sealing part is 300 g / m <2> / 24hr or less. The sealing part 30 may cover the peripheral end surface of the polarizing plate 20 (namely, the polarizing film 21 and the protective film 22), may cover the whole peripheral end surface of the adhesive layer 50, It may be partially covered or may not be covered. In the example of illustration, the sealing part 30 has covered the peripheral end surface of the polarizing plate 20 and the adhesive layer 50. As shown in FIG. In addition, the sealing part 30 may cover only the peripheral end surface of the polarizing plate 20, and may cover the part other than a peripheral end surface with the peripheral end surface. Typically, the sealing part 30 covers the whole surface of the circumferential cross section of a polarizing plate, and covers the whole surface on the opposite side to the liquid crystal cell 10 of a polarizing plate like the example of illustration. In addition, the sealing part 30 should just cover the peripheral end surface of the polarizing plate 20, and the said peripheral end surface should be sealed, and it does not need to be in close contact with the said peripheral end surface.

The amount of color loss after the liquid crystal display device 100 (substantially the polarizing plate 20) is maintained at 85 ° C. and 85% RH for 120 hours is preferably 100 μm or less, more preferably 50 μm or less, More preferably, it is 30 micrometers or less, Especially preferably, it is 25 micrometers or less. The lower limit of the amount of color loss is preferably zero, and in one embodiment, 5 µm. The amount of color loss can be calculated as follows: A test piece having a predetermined size is cut out from the polarizing plate (or the polarizing film) with two sides facing each other in the stretching direction and the stretching direction. In addition, the extending direction typically corresponds to the absorption axis direction of the polarizing film. The stretching direction may correspond, for example, to the longitudinal direction (the conveying direction (MD direction)) of the polarizing plate. Next, a test piece is bonded to a glass plate with an adhesive, and it is set as a liquid crystal display device replacement product. This liquid crystal display replacement product is humidified by leaving to stand in 85 degreeC and 85% RH oven for 120 hours. When the test piece after humidification is arrange | positioned in the state of a standard polarizing plate and cross nicol, the color fading state of the edge part of the test piece after humidification is investigated by a microscope. Specifically, the magnitude | size (color fallout amount: micrometer) of color fallout from the test piece (polarizing plate or polarizing film) edge part is measured. As shown in FIG. 2, the larger one is color fading quantity among the color fading amount a from the edge part of an extending direction, and the color fading amount b from the edge part of the direction orthogonal to an extending direction. In addition, the colored region has a remarkably low polarization characteristic and does not substantially perform a function as a polarizing plate. Therefore, the smaller the amount of color loss, the more preferable.

In the example of illustration, the case where the structure of the polarizing plate and sealing part in this invention was applied to the visual recognition side part of a liquid crystal display device was demonstrated, As mentioned above, the said structure may be applied to the back side part of a liquid crystal display device, and It may be applied to both the visible side portion and the back side portion of the display device, may be applied to an organic EL display device, or may be applied to a quantum dot display device. In addition, since an organic EL display device and a quantum dot display device can also employ | adopt the structure well known in the industry, detailed description is abbreviate | omitted.

Hereinafter, the optical film and optical member used for the image display apparatus of this invention are demonstrated.

B. Polarizer

B-1. Polarizer

The polarizing film 21 is comprised from the PVA system resin film containing iodine as mentioned above.

Arbitrary appropriate resin can be employ | adopted as PVA system resin which forms the said PVA system resin film. For example, polyvinyl alcohol and an ethylene-vinyl alcohol copolymer can be mentioned. Polyvinyl alcohol can be obtained by saponifying polyvinyl acetate. The ethylene-vinyl alcohol copolymer can be obtained by saponifying the ethylene-vinyl acetate copolymer. The saponification degree of PVA resin is 85 mol%-100 mol% normally, Preferably they are 95.0 mol%-99.95 mol%, More preferably, they are 99.0 mol%-99.93 mol%. Saponification degree can be calculated | required according to JISK6726-1994. By using PVA-type resin of such saponification degree, the polarizing film excellent in durability can be obtained. If the degree of saponification is too high, there is a risk of gelation.

The average degree of polymerization of the PVA-based resin may be appropriately selected according to the purpose. The average degree of polymerization is usually 1000 to 10,000, preferably 1200 to 5000, and more preferably 1500 to 4500. In addition, an average degree of polymerization can be calculated | required according to JISK6726-1994.

As described above, the polarizing film contains iodine. The polarizing film is substantially a PVA-based resin film in which iodine is adsorbed and aligned. The iodine concentration in a PVA system resin film is 5.0 weight%-12.0 weight%, for example. In addition, the boric acid concentration in a PVA system resin film is 12 weight%-25 weight%, for example.

The thickness of a PVA system resin film (polarizing film) is 8 micrometers or less as mentioned above, Preferably it is 7 micrometers or less, More preferably, it is 6 micrometers or less. On the other hand, the thickness of a PVA system resin film becomes like this. Preferably it is 1.0 micrometer or more, More preferably, it is 2.0 micrometers or more.

The polarizing film preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance of the polarizing film is preferably 40.0% to 46.0%, more preferably 41.0% to 45.0%. The polarization degree of the polarizing film is preferably 99.9% or more, more preferably 99.95% or more, and still more preferably 99.98% or more. When a polarizing plate is applied to a reflective liquid crystal display device or an organic EL display device, the polarization degree of the polarizing film is preferably 90% or more, more preferably 93% or more, and still more preferably 95% or more. As described above, by forming a sealing portion covering the peripheral end face of the polarizing film and the protective film, such excellent optical properties (excellent balance of single transmittance and polarization degree) and excellent durability (maintaining such excellent optical properties even in a humid environment) Can be compatible).

B-2. Protective film

The protective film 22 is comprised from any suitable film which can be used as a protective film of a polarizing film. As a specific example of the material used as the main component of the said film, cellulose resins, such as triacetyl cellulose (TAC), polyester type, polyvinyl alcohol type, polycarbonate type, polyamide type, polyimide type, polyether sulfone type, and polysulfone Transparent resins, such as a phone type, a polystyrene type, a polynorbornene type, a polyolefin type, a (meth) acrylic type, an acetate type, etc. are mentioned. Moreover, thermosetting resins, such as a (meth) acrylic-type, a urethane type, a (meth) acrylic-type urethane type, an epoxy type, a silicone type, or ultraviolet curable resin, etc. are mentioned. In addition, glassy polymers, such as a siloxane polymer, are mentioned, for example. Moreover, the polymer film of Unexamined-Japanese-Patent No. 2001-343529 (WO01 / 37007) can also be used. As the material of the film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain can be used. For example, isobutene and N The resin composition which has the alternating copolymer which consists of -methyl maleimide, and an acrylonitrile styrene copolymer is mentioned. The polymer film may be, for example, an extrusion molded product of the resin composition.

In embodiment of this invention, you may use the resin base material used in manufacture of a polarizing plate (it mentions later in item E) as a protective film.

When a polarizing plate is arrange | positioned at the visual recognition side of a display cell and a protective film is arrange | positioned at the visual recognition side of a polarizing film like an example of illustration, a protective coat, an anti-reflective process, an anti-sticking process, and an antiglare process are carried out to a protective film as needed. Surface treatments, such as these, may be performed.

As long as the thickness of a protective film can acquire the effect of this invention, arbitrary appropriate thickness can be employ | adopted. The thickness of a protective film is 20 micrometers-40 micrometers, for example, Preferably they are 25 micrometers-35 micrometers. In addition, when surface treatment is given, the thickness of a protective film is the thickness containing the thickness of a surface treatment layer.

When arrange | positioning another protective film (inner side protective film) between the polarizing film 21 and the adhesive layer 50, it is preferable that the said inner side protective film is optically isotropic. In this specification, "optically isotropic" means that in-plane phase difference Re (550) is 0 nm-10 nm, and phase difference Rth (550) of thickness direction is -10 nm-+10 nm. Re (550) of the inner protective film is preferably 0 nm to 8 nm, more preferably 0 nm to 6 nm, still more preferably 0 nm to 3 nm. Rth (550) of the inner protective film is preferably -8 nm to +8 nm, more preferably -6 nm to +6 nm, still more preferably -3 nm to +3 nm. 'Re (550)' is an in-plane retardation measured by light having a wavelength of 550 nm at 23 ° C. Re (550) can be calculated | required by Formula: Re (550) = (nx-ny) xd, when the thickness of a layer (film) is d (nm). In addition, "Rth (550)" is a phase difference of the thickness direction measured with the light of wavelength 550nm in 23 degreeC. Rth (550) can be obtained by the formula: Rth (550) = (nx-nz) x d when the thickness of the layer (film) is d (nm).

C. Seals

By covering the peripheral end surface of the polarizing plate 20 as mentioned above, the sealing part 30 maintains the optical characteristic of a polarizing plate even in a humidification environment, and improves durability of a polarizing plate. Therefore, it is preferable that a sealing part has a barrier function. As used herein, "having a barrier function" means controlling the transmission amount of oxygen and / or water vapor invading the polarizing film to substantially block the polarizing film from them.

The seal has barrier properties as described above, and typically has barrier properties against moisture and gas (eg, oxygen). The water vapor transmission rate (permeability) under the conditions of 40 ° C. and 90% RH of the seal is preferably 300 g / m 2/24 hr or less, more preferably 100 g / m 2/24 hr or less, still more preferably 70 g / m 2/24 hr or less. Especially preferably, it is 40 g / m <2> / 24hr or less. The lower limit of the moisture permeability is, for example, 0.01 g / m 2/24 hr, preferably below the detection limit. If the water vapor transmission rate of a sealing part is such a range, a polarizing film can be favorably protected from the moisture and oxygen in air. In addition, the water vapor transmission rate can be measured according to JIS Z0208.

The seal can be made of any suitable material, as long as it can satisfy the above characteristics. As an constituent material, the adhesive agent composition is mentioned typically. In this specification, an "adhesive composition" is meant to include both an adhesive (adhesive composition) and an adhesive composition.

As an adhesive composition, the rubber adhesive composition which uses a rubber polymer as a base polymer is mentioned, for example.

Examples of the rubber polymer include copolymerizing a conjugated diene polymer obtained by polymerizing one conjugated diene compound, a conjugated diene copolymer obtained by polymerizing two or more conjugated diene compounds, a conjugated diene compound and an aromatic vinyl compound. The conjugated diene copolymer obtained and these hydrogenated substances are mentioned.

It will not specifically limit, if it is a monomer which has a conjugated diene which can superpose | polymerize as a conjugated diene compound. Specific examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-hepta Dienes and 1,3-hexadiene. Among these, 1,3-butadiene and isoprene are preferable from the viewpoint of industrial availability. The conjugated diene compound may be used alone or in combination.

It will not specifically limit, if it is a monomer which has an aromatic vinyl structure copolymerizable with a conjugated diene compound as an aromatic vinyl compound. Specific examples of the aromatic vinyl compound include styrene, p-methyl styrene, α-methyl styrene, vinyl ethylbenzene, vinyl xylene, vinyl naphthalene, diphenylethylene, and the like. Among these, styrene is preferable from the viewpoint of industrial availability. An aromatic vinyl compound may be used independently and may be used in combination.

The diene copolymer may be a random copolymer or a block copolymer. Moreover, you may copolymerize compounds other than a conjugated diene compound and an aromatic vinyl compound, and may obtain a diene copolymer.

In the conjugated diene-based copolymer obtained by copolymerizing a conjugated diene compound and an aromatic vinyl compound, the molar ratio of the conjugated diene compound and the aromatic vinyl compound is preferably conjugated diene compound / aromatic vinyl compound = 10/90 to 90/10 (mol%). .

Specific examples of such conjugated diene-based (co) polymers include butadiene rubber (BR), isoprene rubber (IR), styrene-butadiene copolymer (SBR), butadiene-isoprene-styrene random copolymers, isoprene-styrene random copolymers, Styrene-isoprene block copolymer (SIS), butadiene-styrene copolymer, styrene-ethylene-butadiene block copolymer (SEBS), and acrylonitrile-butadiene rubber (NBR). These may be used alone or in combination. Among these, an isoprene-styrene copolymer is preferable. Moreover, these hydrogenated substances can also be used preferably.

As the rubber polymer, in addition to the conjugated diene-based (co) polymer, isobutylene (IB), styrene-isobutylene-styrene block copolymer (SIBS), styrene-ethylene propylene copolymer-styrene block copolymer, and the like can also be used. The rubber polymer may be used alone or in combination.

Rubber-based polymers that can be used in the present invention are preferably at least 50% by weight, more preferably at least 70% by weight, even more preferably at least 80% by weight, particularly of the conjugated diene-based (co) polymer in the whole rubber-based polymer. Preferably at least 90% by weight. The upper limit of the content of the conjugated diene-based (co) polymer is not particularly limited, and may be 100% by weight (that is, a rubber polymer composed of only the conjugated diene-based (co) polymer).

As described above, the pressure-sensitive adhesive composition includes a rubber polymer as a base polymer. Content of the rubber polymer in an adhesive composition becomes like this. Preferably it is 40 weight% or more, More preferably, it is 50 weight% or more, More preferably, it is 60 weight% or more. The upper limit of the content of the rubber polymer is not particularly limited and is, for example, 90% by weight or less.

The pressure-sensitive adhesive composition may further include any suitable additive in addition to the rubber polymer. Specific examples of the additives include crosslinking agents (e.g., polyisocyanates, epoxy compounds, alkyletherized melamine compounds, etc.), tackifiers (e.g., rosin derivative resins, polyterpene resins, petroleum resins, fat-soluble phenol resins, vinyltoluene resins, etc.); Plasticizers, fillers (e.g., layered silicates, clay materials, and the like) and anti-aging agents. The kind, combination, addition amount, etc. of the additive added to an adhesive composition can be suitably set according to the objective. Content (total amount) of the additive in an adhesive composition becomes like this. Preferably it is 60 weight% or less, More preferably, it is 50 weight% or less, More preferably, it is 40 weight% or less.

Typical examples of the adhesive composition include an active energy ray curable adhesive composition and a heat curable adhesive composition. As an active energy ray hardening-type adhesive composition, a light (for example, ultraviolet-ray) curable adhesive composition and an electron beam curable adhesive composition are mentioned, for example. As an active energy ray hardening-type adhesive composition, it can select as needed, such as a radical hardening type, a cation hardening type, and an anion hardening type, For example, it can also be used combining suitably, such as a hybrid of a radical hardening type and a cation hardening type.

In one embodiment, the adhesive composition is an ultraviolet curable adhesive composition. As an ultraviolet curing adhesive composition, the adhesive composition of Unexamined-Japanese-Patent No. 2013-227419 can be used preferably, for example. The description of this publication is incorporated herein by reference.

The thickness of the sealing portion is, for example, about 10 µm to 200 µm, preferably 15 µm to 100 µm, more preferably 20 µm to 70 µm, and still more preferably 25 µm to 50 µm. In this specification, unless otherwise indicated, "thickness of a sealing part" is thickness of the direction which extends outward from the peripheral end surface of a polarizing film and a protective film. In addition, when the sealing part is shaving | covering on the opposite side to the liquid crystal cell of a polarizing plate, the thickness of the sealing part in the said surface is 10 micrometers-about 200 micrometers, for example, Preferably it is 15 micrometers-100 micrometers, More preferably, 20 micrometers It is -70 micrometers, More preferably, it is 25 micrometers-50 micrometers.

D. Adhesive layer

The pressure-sensitive adhesive layer 50 is composed of any suitable pressure-sensitive adhesive. An acrylic adhesive is mentioned as a typical example of an adhesive. The thickness of an adhesive layer is 20 micrometers-100 micrometers, for example.

E. Manufacturing Method of Image Display Device

The manufacturing method of the image display apparatus of this invention covers arrange | positioning a polarizing plate on one side of a display cell, forming a sealing part so that the peripheral end surface of a polarizing plate may be covered, and covering it to the opposite side to the display cell of a polarizing plate as needed. Arranging the glass. Hereinafter, as a representative example of the manufacturing method of the image display apparatus of this invention, embodiment which includes arrange | positioning a polarizing plate in the visual recognition side part of a liquid crystal display device, and forming a sealing part in the peripheral end surface of the said polarizing plate is described. The said embodiment corresponds to the manufacturing method of the liquid crystal display device described in the said A item.

E-1. Polarizing film manufacturers

The manufacturing method of the polarizing plate which concerns on one Embodiment of this invention typically forms a PVA system resin layer on one side of a resin base material, and extend | stretches and dyes the laminated body of this resin base material and this PVA system resin layer. To include the PVA resin layer as a polarizing film. In another embodiment, you may produce the laminated body of a resin base material and a PVA-type resin film, dye the said laminated body, and may use this PVA-type resin film as a polarizing film. Furthermore, in another embodiment, you may extend | stretch and dye a single PVA system resin film, and may make this PVA system resin film a polarizing film. Hereinafter, as a representative example, the manufacturing method including forming a PVA system resin layer on one side of a resin base material is demonstrated.

E-1-1. Formation of PVA Resin Layer

Arbitrary suitable methods can be employ | adopted as a formation method of a PVA system resin layer. Preferably, the PVA system resin layer is formed by apply | coating and drying the coating liquid containing PVA system resin on a resin base material.

Arbitrary appropriate thermoplastic resins can be employ | adopted as a formation material of the said resin base material. Examples of the thermoplastic resins include ester resins such as polyethylene terephthalate resins, cycloolefin resins such as norbornene resins, olefin resins such as polypropylene, polyamide resins, polycarbonate resins, and copolymer resins thereof. Can be mentioned. Among these, Preferably, it is norbornene-type resin and amorphous polyethylene terephthalate type resin.

In one embodiment, amorphous (non-crystallized) polyethylene terephthalate resin is preferably used. Especially, non-crystalline (hard to crystallize) polyethylene terephthalate type resin is used preferably. As a specific example of amorphous polyethylene terephthalate type resin, the copolymer which further contains isophthalic acid as dicarboxylic acid, and the copolymer which further contains cyclohexane dimethanol as glycol are mentioned.

In the stretching described below, when the underwater stretching method is employed, the resin substrate absorbs water, and the plasticizer may act to plasticize the water. As a result, the stretching stress can be greatly reduced, the stretching can be performed at a high magnification, and the stretching property can be superior to that in the case of air stretching. As a result, the polarizing film which has the outstanding optical characteristic can be manufactured. In one embodiment, the water absorption of the resin base material becomes like this. Preferably it is 0.2% or more, More preferably, it is 0.3% or more. On the other hand, the water absorption of a resin base material becomes like this. Preferably it is 3.0% or less, More preferably, it is 1.0% or less. By using such a resin base material, dimensional stability can remarkably fall at the time of manufacture, and the problem of deterioration of the external appearance of the polarizing film obtained can be prevented. Moreover, when extending | stretching in water, it can prevent that a base material fractures or a PVA system resin layer peels from a resin base material. In addition, the water absorption of a resin base material can be adjusted, for example by introducing a modifying group into a formation material. Water absorption is a value which can be calculated | required according to JISK7209.

Glass transition temperature (Tg) of a resin base material becomes like this. Preferably it is 170 degrees C or less. By using such a resin base material, the stretchability of a laminated body can fully be ensured, suppressing the crystallization of a PVA system resin layer. Furthermore, when considering plasticizing of the resin base material by water and performing extending | stretching in water favorably, it is more preferable that it is 120 degrees C or less. In one embodiment, the glass transition temperature of a resin base material becomes like this. Preferably it is 60 degreeC or more. By using such a resin base material, when apply | coating and drying the coating liquid containing the said PVA system resin, the resin base material prevents problems, such as a deformation | transformation (for example, unevenness | corrugation, sagging, wrinkles, etc.), and is favorable. A laminate can be produced. Moreover, extending | stretching of a PVA system resin layer can be performed favorably at suitable temperature (for example, about 60 degreeC). In another embodiment, if a resin base material does not deform | transform at the time of apply | coating and drying a coating liquid containing PVA system resin, the glass transition temperature lower than 60 degreeC may be sufficient. In addition, the glass transition temperature of a resin base material can be adjusted by heating using the crystallization material which introduce | transduces a modifying group into a formation material, for example. Glass transition temperature (Tg) is a value which can be calculated | required according to JISK71121.

Preferably the thickness before extending | stretching of a resin base material is 20 micrometers-300 micrometers, More preferably, they are 50 micrometers-200 micrometers. If it is less than 20 micrometers, there exists a possibility that formation of a PVA system resin layer may become difficult. When it exceeds 300 micrometers, for example, in water-based stretching, there exists a possibility that a resin base material may require a long time for absorbing water, and an excessive load may be required for extending | stretching.

The said coating liquid is typically the solution which melt | dissolved the said PVA-type resin in the solvent. Examples of the solvent include polyhydric alcohols such as water, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, various glycols and trimethylolpropane, and amines such as ethylenediamine and diethylenetriamine. Can be. These can be used individually or in combination of 2 or more types. Among these, Preferably it is water. The PVA resin concentration of the solution is preferably 3 parts by weight to 20 parts by weight with respect to 100 parts by weight of the solvent. If it is such resin concentration, the uniform coating film in close_contact | adherence to a resin base material can be formed.

You may mix | blend an additive with a coating liquid. As an additive, a plasticizer, surfactant, etc. are mentioned, for example. As a plasticizer, polyhydric alcohols, such as ethylene glycol and glycerin, are mentioned, for example. As surfactant, a nonionic surfactant is mentioned, for example. These can be used for the purpose of further improving the uniformity, dyeing property, and stretchability of the obtained PVA system resin layer. Moreover, as an additive, an easily bonding component is mentioned, for example. By using an easily bonding component, the adhesiveness of a resin base material and a PVA system resin layer can be improved. As a result, for example, problems such as peeling off of the PVA-based resin layer from the substrate can be suppressed, and dyeing and stretching in water described later can be satisfactorily performed. As an easily bonding component, modified PVA, such as acetoacetyl modified PVA, is used, for example.

Arbitrary appropriate methods can be employ | adopted as a coating method of a coating liquid. For example, the roll coating method, the spin coating method, the wire bar coating method, the dip coating method, the die coating method, the curtain coating method, the spray coating method, the knife coating method (comma coat method etc.) etc. are mentioned.

Coating and drying temperature of the said coating liquid becomes like this. Preferably it is 50 degreeC or more.

Before forming a PVA-type resin layer, surface treatment (for example, corona treatment etc.) may be given to a resin base material, and an easily bonding layer may be formed on a resin base material. By performing such a process, the adhesiveness of a resin base material and a PVA system resin layer can be improved.

Preferably the thickness of the said PVA system resin layer (before extending | stretching) is 3 micrometers-20 micrometers.

E-1-2. Stretch

Arbitrary suitable methods may be employ | adopted as the extending method of a laminated body. Specifically, fixed-end stretching may be sufficient, and free-end stretching may be sufficient (for example, the method of carrying out a uniaxial stretching by passing a laminated body between rolls with different circumferential speeds). Preferably, it is free end drawing.

The stretching direction of the laminate can be appropriately set. In one embodiment, it extends in the longitudinal direction of a long laminated body. In this case, typically, the method of extending | stretching and letting a laminated body pass between rolls with different circumferential speeds is employ | adopted. In another embodiment, the film is stretched in the width direction of the long laminate. In this case, typically, the method of extending | stretching using a tenter drawing machine is employ | adopted.

The stretching method is not particularly limited, and may be an air stretching method or an underwater stretching method. Preferably, it is an underwater drawing system. According to the underwater stretching method, it can extend | stretch at the temperature lower than the glass transition temperature (typically about 80 degreeC) of the said resin base material and PVA system resin layer, and it is high magnification, suppressing the crystallization of a PVA system resin layer. You can stretch. As a result, the polarizing film which has the outstanding optical characteristic can be manufactured.

Stretching of the laminate may be performed in one step or may be performed in multiple steps. When performing in multiple stages, for example, the free end stretching and the fixed end stretching may be combined, and the underwater stretching method and the aerial stretching method may be combined. In addition, when performing in multiple steps, the draw ratio (maximum draw ratio) of the laminated body mentioned later is a product of draw ratio of each step.

The stretching temperature of the laminate may be set to any appropriate value depending on the material of formation of the resin substrate, the stretching method and the like. In the case of employing the air-stretching system, the stretching temperature is preferably equal to or higher than the glass transition temperature (Tg) of the resin substrate, and more preferably, equal to or higher than the glass transition temperature (Tg) of the resin substrate + 10 ° C, particularly preferably Tg + It is 15 degreeC or more. On the other hand, extending | stretching temperature of a laminated body becomes like this. Preferably it is 170 degrees C or less. By extending | stretching at such temperature, it can suppress that the crystallization of PVA system resin advances rapidly, and can suppress the problem by the said crystallization (for example, disturbing the orientation of the PVA system resin layer by extending | stretching).

When employ | adopting an underwater extending | stretching system, the liquid temperature of an extending | stretching bath is 60 degreeC or more, Preferably it is 65 degreeC-85 degreeC, More preferably, it is 65 degreeC-75 degreeC. If it is such temperature, it can extend | stretch at high magnification, suppressing melt | dissolution of a PVA system resin layer. Specifically, as mentioned above, the glass transition temperature (Tg) of a resin base material is 60 degreeC or more preferably in relationship with formation of a PVA system resin layer. In this case, when extending | stretching temperature is less than 60 degreeC, even if it considers plasticization of the resin base material by water, there exists a possibility that it cannot extend | stretch satisfactorily. On the other hand, the higher the temperature of the stretching bath, the higher the solubility of the PVA-based resin layer, and there is a fear that excellent optical properties cannot be obtained. Immersion time of the laminated body in an extending | stretching bath becomes like this. Preferably it is 15 second-5 minutes.

When employ | adopting an underwater extending | stretching system, it is preferable to immerse and extend | stretch a laminated body in boric-acid aqueous solution (stretching in boric acid underwater). By using boric acid aqueous solution as a stretching bath, the rigidity which bears the tension | tensile_strength applied at the time of extending | stretching to a PVA system resin layer, and water resistance which does not melt | dissolve in water can be provided. Specifically, the boric acid may be cross-linked by hydrogen bonding with the PVA resin by generating tetrahydroxyboric anion in an aqueous solution. As a result, rigidity and water resistance can be provided to a PVA resin layer, it can extend | stretch favorable, and the polarizing film which has the outstanding optical characteristic can be manufactured.

The boric acid aqueous solution is preferably obtained by dissolving boric acid and / or borate in water as a solvent. In this invention, boric acid concentration is 4.5 weight% or less, Preferably it is 2.0 weight%-4.5 weight%, More preferably, it is 2.5 weight%-4.0 weight%. In addition to boric acid or borate, an aqueous solution obtained by dissolving a boron compound such as borax, glyoxal, glutaraldehyde or the like in a solvent can also be used.

When the dichroic substance (typically iodine) is adsorb | sucked to PVA system resin layer previously by the dyeing mentioned later, Preferably, iodide is mix | blended with the said stretching bath (boric acid aqueous solution). By mix | blending an iodide, the elution of the iodine made to adsorb | suck to the PVA system resin layer can be suppressed. Examples of iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, titanium iodide and the like. Among these, potassium iodide is preferable. The concentration of the iodide is preferably 0.05 parts by weight to 15 parts by weight, more preferably 0.5 parts by weight to 8 parts by weight with respect to 100 parts by weight of water.

The draw ratio (maximum draw ratio) of the laminate is preferably 5.0 times or more with respect to the original length of the laminate. Such a high draw ratio can be achieved, for example, by employing the underwater stretching method (boric acid underwater stretching). In addition, in this specification, a "maximum draw ratio" means the draw ratio immediately before a laminated body breaks, and separately confirms the draw ratio which a laminated body breaks, and means the value lower than the value.

In one embodiment, after air-stretching the said laminated body at high temperature (for example, 95 degreeC or more), the said boric acid underwater drawing and dyeing mentioned later are performed. Since such aerial stretching can be established as a preliminary or auxiliary stretching to boric acid underwater stretching, it is called "air auxiliary stretching" hereafter.

By combining air assisted stretching, the laminate may be stretched at a higher magnification. As a result, the polarizing film which has more excellent optical characteristics (for example, polarization degree) can be manufactured. For example, when polyethylene terephthalate-based resin is used as the resin substrate, the combination of air assisted stretching and boric acid underwater stretching can be stretched while suppressing the orientation of the resin substrate, rather than stretching only by boric acid underwater stretching. While the orientation of the resin substrate is improved, the stretching tension is increased, so that stable stretching is difficult or broken. Therefore, a laminated body can be extended | stretched at higher magnification by extending | stretching, suppressing the orientation of a resin base material.

Moreover, by combining air assisted stretching, the orientation of the PVA-based resin can be improved, and therefore, the orientation of the PVA-based resin can be improved even after stretching in boric acid in water. Specifically, by preliminarily improving the orientation of the PVA-based resin by air-assisted stretching, when the boric acid is drawn in water, the PVA-based resin is easily crosslinked with boric acid or is drawn in a state in which the boric acid is a nodal point, thereby stretching the boric acid in water. It is estimated that the orientation of PVA resin will become high afterwards. As a result, the polarizing film which has the outstanding optical characteristic (for example, polarization degree) can be manufactured.

The draw ratio in the air assisted stretching is preferably 3.5 times or less. It is preferable that the extending | stretching temperature of air auxiliary extending | stretching is more than the glass transition temperature of PVA system resin. The stretching temperature is preferably 95 ° C to 150 ° C. In addition, the maximum draw ratio in the case of combining air assisted stretching and the above-mentioned boric acid underwater stretching is preferably 5.0 times or more, more preferably 5.5 times or more, further preferably 6.0 times or more with respect to the original length of the laminate. to be.

E-1-3. dyeing

The dyeing of the PVA-based resin layer is typically performed by adsorbing iodine on the PVA-based resin layer. As the adsorption method, for example, a method of immersing a PVA-based resin layer (laminate) in a dyeing solution containing iodine, a method of coating the dyeing solution on a PVA-based resin layer, and spraying the dyeing solution on a PVA-based resin layer The method etc. are mentioned. Preferably, it is a method of immersing a PVA system resin layer (laminated body) in a dyeing liquid. This is because iodine can adsorb well.

The dyeing solution is preferably an iodine aqueous solution. The blending amount of iodine is preferably 0.1 parts by weight to 0.5 parts by weight with respect to 100 parts by weight of water. In order to improve the solubility of iodine in water, it is preferable to mix iodide in an iodine aqueous solution. Specific examples of the iodide are as described above. The blending amount of the iodide is preferably 0.02 parts by weight to 20 parts by weight, more preferably 0.1 parts by weight to 10 parts by weight with respect to 100 parts by weight of water. The liquid temperature at the time of dyeing of the dyeing solution is preferably 20 ° C to 50 ° C in order to suppress dissolution of the PVA-based resin. When the PVA resin layer is immersed in the dye solution, the immersion time is preferably 5 seconds to 5 minutes in order to secure the transmittance of the PVA resin layer. In addition, dyeing conditions (concentration, liquid temperature, immersion time) can be set so that the polarization degree or single transmittance of the finally obtained polarizing film may become a predetermined range. In one embodiment, the immersion time is set so that the polarization degree of the polarizing film obtained may be 99.98% or more. In another embodiment, the immersion time is set so that the unitary transmittance of the polarizing film obtained will be 40.0%-42.5%.

The dyeing process can be performed at any suitable timing. When the above-mentioned stretching is carried out, it is preferably performed before the stretching in water.

E-1-4. Other processing

In addition to extending | stretching and dyeing, the said PVA system resin layer (laminated body) may be suitably performed the process for making it a polarizing film. Examples of the treatment for the polarizing film include insolubilization treatment, crosslinking treatment, washing treatment, drying treatment, and the like. In addition, the frequency | count, order, etc. of these processes are not specifically limited.

The insolubilization treatment is typically performed by immersing a PVA-based resin layer (laminate) in an aqueous boric acid solution. By performing insolubilization treatment, water resistance can be imparted to the PVA-based resin layer. The concentration of the boric acid aqueous solution is preferably 1 part by weight to 4 parts by weight with respect to 100 parts by weight of water. The liquid temperature of the insolubilization bath (boric acid solution solution) is preferably 20 ° C to 50 ° C. Preferably, the insolubilization treatment is performed before the underwater stretching or the dyeing treatment.

The crosslinking treatment is typically performed by immersing a PVA-based resin layer (laminate) in an aqueous boric acid solution. By performing a crosslinking process, water resistance can be provided to a PVA system resin layer. The concentration of the boric acid aqueous solution is preferably 1 part by weight to 5 parts by weight with respect to 100 parts by weight of water. In addition, when performing a crosslinking process after the said dyeing process, it is preferable to mix | blend an iodide further. By mix | blending an iodide, the elution of the iodide adsorbed to the PVA system resin layer can be suppressed. The compounding quantity of iodide is 1 weight part-5 weight part preferably with respect to 100 weight part of water. Specific examples of the iodide are as described above. The liquid temperature of the crosslinking bath (boric acid solution solution) is preferably 20 ° C to 60 ° C. Preferably, the crosslinking treatment is carried out before the underwater stretching. In a preferred embodiment, aerial stretching, dyeing treatment and crosslinking treatment are carried out in this order.

The said washing process is typically performed by immersing a PVA system resin layer (laminated body) in the potassium iodide aqueous solution. Preferably the drying temperature in the said drying process is 30 degreeC-100 degreeC.

As described above, the polarizing film is formed on the resin substrate.

E-2. Placement of Polarizer

In one embodiment, the laminated body of the resin base material and polarizing film obtained by said E-1 item is arrange | positioned as the polarizing plate 20 in the visual recognition side of the liquid crystal cell 10. In another embodiment, a protective film is bonded together to the polarizing film surface of the laminated body of a resin base material (protective film) and a polarizing film (For convenience, this protective film is called another protective film.). The laminated body of the obtained resin base material (protective film) / polarizing film / another protective film is arrange | positioned as the polarizing plate 20 on the visual recognition side of the liquid crystal cell 10. Furthermore, in another embodiment, a protective film is bonded to the polarizing film surface of the laminated body of a resin base material and a polarizing film, and then a resin base material is peeled off. The laminated body of the obtained polarizing film / protective film is arrange | positioned as the polarizing plate 20 on the visual recognition side of the liquid crystal cell 10. Furthermore, in another embodiment, another protective film is bonded to the polarizing film surface (resin base material peeling surface) of the laminated body of said polarizing film / protective film, and the laminated body of a protective film / polarizing film / another protective film is a polarizing plate ( 20 is disposed on the viewing side of the liquid crystal cell 10. Typically, as shown to Fig.3 (a), the polarizing plate 20 is bonded to the liquid crystal cell 10 (substantially the visual side of a liquid crystal cell) via the adhesive layer 50. As shown to FIG. In addition, as shown in FIG. 3A, the size of the polarizing plate 20 is typically smaller than the size of the liquid crystal cell 10.

E-3. Formation of the seal

Next, the sealing part is formed so that the circumferential end surface of the polarizing plate 20 arrange | positioned at the liquid crystal cell 10 may be covered. Hereinafter, the case where a sealing part is formed from an adhesive agent composition is demonstrated.

A sealing part is typically formed by arrange | positioning an adhesive agent composition so that the outer peripheral cross section of a laminated body may be covered. A sealing part may be formed by apply | coating and hardening an adhesive composition of a liquid (before hardening) in a predetermined position, and may be formed by arrange | positioning (typically bonding) a sheet-shaped adhesive composition in a predetermined position. In one embodiment, as shown in FIG.3 (b), the sheet | seat which has a magnitude | size larger than a polarizing plate is arrange | positioned so that it may protrude-out from the outer periphery of a polarizing plate. Preferably, it arrange | positions so that it may extend-protrude from all four sides which comprise the outer periphery of a polarizing plate. The length of the extension-projection of the sheet may preferably be set so as to finally cover the front surface of the peripheral cross section of the polarizing plate. The extension-projection of the sheet can be drooped by its own weight to cover the peripheral cross section of the polarizer by adjusting the softness (eg, modulus of elasticity) of the sheet. Alternatively, the extended-projection portion of the sheet may be bent by any suitable operation to cover the peripheral cross section of the polarizing plate. By adopting such a configuration, as shown in Fig. 3C, a sealing portion covering the front surface of the opposite side of the display cell of the polarizing plate and the front surface of the peripheral cross section is formed.

If necessary, the cover glass 40 is disposed on the side opposite to the liquid crystal cell 10 of the polarizing plate 20. Typically, as shown in FIG. 3 (d), the cover glass 40 is attached to the polarizing plate 20 via a sealing part 30 covering a surface on the opposite side to the liquid crystal cell 10 of the polarizing plate 20. It is bonded.

On the back side of the liquid crystal cell 10, the back side polarizing plate and the back side optical member are laminated | stacked according to the procedure known in the industry, and the backlight part (if present) is built-in. In this way, a liquid crystal display device can be obtained.

The above embodiment is an example. The same procedure may be employ | adopted for the back side part of a liquid crystal display device; The visual recognition side part of a liquid crystal display device employ | adopts the order known in the industry, and may employ | adopt the same procedure only to the back side part of a liquid crystal display device; The same procedure may be employed for the organic EL display device; The same procedure may be employed for the quantum dot display device.

EXAMPLE

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples. In addition, the measuring method of each characteristic is as follows.

(1) thickness

It measured using the digital micrometer (KC-351C by Anritsu Corporation).

(2) moisture permeability

Using the pressure-sensitive adhesive compositions prepared in Examples and Comparative Examples, a pressure-sensitive adhesive sheet having a thickness of 50 μm was formed in accordance with the method described in the Examples. One peeling liner of the adhesive sheet is peeled off to expose the adhesive surface, and the adhesive sheet is bonded to a triacetyl cellulose film (TAC film, thickness: 25 µm, manufactured by Konica Minolta Co., Ltd.) via the adhesive surface, and 10 cm Φ. It cut out to the circular shape of. Finally, the other peeling liner was peeled off to obtain a sample for measurement. The moisture permeability (water vapor transmission rate) was measured by the moisture permeability test method (cup method, according to JIS Z 0208) about the obtained measurement sample. In addition, the measurement conditions were as follows. In addition, the constant temperature and humidity tank was used for the measurement.

Measuring temperature: 40 ℃

Relative Humidity: 92%

Measurement time: 24 hours

(3) amount of color loss

From the polarizing plates used in the Example and the comparative example, the test piece (50 mm x 50 mm) which makes two sides which a direction orthogonal to an extending | stretching direction opposes, respectively was cut out, and the test piece was bonded to the alkali free glass plate with the adhesive. Here, the sealing part was formed like the procedure in preparation of the liquid crystal display device of each Example and a comparative example, and the liquid crystal display device replacement product was produced. This was left to stand in an oven at 85 ° C. and 85% RH for 120 hours for humidification, and the color fading state at the end of the polarizing film after humidification when placed in the state of a standard polarizing plate and cross nicol was examined by a microscope. Specifically, the magnitude | size (color fallout amount: micrometer) of the color fallout from the polarizing film edge part was measured. The amount of color fading was measured from the image photographed by 10 times magnification using the MX61L by Olympus company as a microscope. As shown in FIG. 2, the larger one of the color fading amount a from the edge part of the extending | stretching direction, and the color fading amount b from the edge part orthogonal to the extending | stretching direction was made into the color fading amount.

(4) color fading, light leakage and white-blur

After forming an acrylic adhesive layer (thickness: 20 micrometers) in the polarizing film surface of the polarizing plate obtained by an Example and a comparative example, it cut out to 50 mm x 50 mm, and bonded together to the alkali free glass surface of 100 mm x 100 mm through an adhesive layer. . Next, the sheet-like adhesive used in the Example and the comparative example was arrange | positioned at the surface on the opposite side to the alkali free glass of a polarizing plate, respectively. Here, the sheet was arranged so as to extend-protrude from all four sides constituting the outer circumference of the polarizing plate. The length of the four extension-protrusions was 5 mm each. The sheet sag by its own weight to be in direct contact with the glass, covering the outer circumferential end face of the polarizing plate, and sealing. In this way, the sealing part which covers the front surface of a polarizing plate surface and the front surface of an outer peripheral cross section was formed. Next, the cover glass (thickness 1mm) was bonded together through the sealing part (adhesive agent). Next, the same polarizing plate was also bonded together to the back side of glass through the acrylic adhesive layer (thickness: 25 micrometers). Thus, the liquid crystal display replacement product was produced. At the same time, an earth that does not transmit visible light, punched out in the same size as the polarizing plate, is prepared and installed on the LED light in a state of being superimposed on the liquid crystal display device replacement product, causing color loss, light leakage and White-blur was visually observed. Subsequently, after the liquid crystal display replacement product was placed in an environment of 85 ° C. and 85% RH for 120 hours, the earth and the LED light were again set, and color fading, light leakage and white-blur from near the polarizer cross section were visually observed.

Example 1

As a resin substrate, an amorphous polyethylene terephthalate (IPA copolymer PET) film having 7 mol% of an isophthalic acid unit having a thickness of 100 μm and a Tg of 75 ° C. was prepared. Corona treatment (58 W / m <^2> / min) was given to the surface of this film.

Acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name: High Sepamer Z200 Average degree of polymerization: 1200, Saponification degree: 98.5 mol% or more, Acetoacetylation degree: 5%), and PVA (Average degree of polymerization: 4200, Saponification degree: 99.2) PVA-based resin containing a molar%) in a ratio of 1: 9 was prepared, and 13 parts by weight of potassium iodide was added to 100 parts by weight of the PVA-based resin to prepare an aqueous PVA-based resin solution (PVA-based resin concentration: 5.5 weight). %). This aqueous solution was applied to the corona-treated surface of the resin substrate so that the film thickness after drying was 13 µm, and dried for 10 minutes by hot air drying under an atmosphere of 60 ° C to form a PVA resin layer having a thickness of 9 µm on the resin substrate. It was. In this manner, a laminate was produced.

The obtained laminate was stretched 2.4 times at 140 ° C. in air (air assisted stretching).

Then, the laminated body was immersed in the boric acid aqueous solution of 30 degreeC of liquid temperature for 30 second, and the PVA system resin layer was insolubilized. The boric acid aqueous solution of this process made boric acid content 3 weight part with respect to 100 weight part of water.

Subsequently, the laminate was immersed and dyed in a dyeing solution containing iodine and potassium iodide at a liquid temperature of 30 ° C. for an arbitrary time such that the single layer transmittance of the resulting polarizing film was about 42 to 45%. The dyeing solution is water as a solvent, the iodine concentration is in the range of 0.1 to 0.4% by weight, the potassium iodide concentration is in the range of 0.7 to 2.8% by weight, and the ratio of the concentration of iodine and potassium iodide is 1: 7. It was.

Then, the laminated body was immersed in 30 degreeC boric-acid aqueous solution for 60 second, and the crosslinking process was performed to the PVA resin layer which adsorbed iodine. The boric acid aqueous solution of this process made boric acid content 3 weight part with respect to 100 weight part of water, and made potassium iodide content 3 weight part with respect to 100 weight part of water.

Furthermore, the laminated body was extended | stretched 2.3 times (final draw ratio 5.50 times) in the same direction as the above air | stretch assisted extension in the boric-acid aqueous solution at the draw temperature of 70 degreeC. The boric acid aqueous solution of this process made boric acid content 3.5 weight part with respect to 100 weight part of water, and potassium iodide content was 5 weight part with respect to 100 weight part of water.

Subsequently, the laminate was washed with an aqueous solution in which potassium iodide content was 4 parts by weight with respect to 100 parts by weight of water, dried by warm air at 60 ° C., and a polarizing film having a thickness of 5 μm was obtained on the resin substrate.

The cycloolefin type film (Nippon Xeon make, ZF-12, 13 micrometers) was bonded to the surface (surface on the opposite side to a resin base material) of the obtained polarizing film via the curable adhesive agent. Specifically, each of the polarizing film and the cycloolefin-based film was coated with a curable adhesive so as to have a thickness of 1.0 μm, and bonded using a roll machine. Thereafter, visible light was irradiated from the cycloolefin-based film side to cure the curable adhesive. Then, the resin base material was peeled off and the polarizing plate which has a structure of a polarizing film / cycloolefin type film (protective film) was obtained. The obtained polarizing plate was used to evaluate the amount of color loss. The results are shown in Table 1. In addition, the state of color loss is shown in FIG.

The liquid crystal panel was taken out from the liquid crystal display device (The Apple Corporation make, brand name "iPad (trademark) Air") of an IPS mode, the optical member, such as a polarizing plate, was removed from this liquid crystal panel, and the liquid crystal cell was taken out. The liquid crystal cell used both the surface (outer of each glass substrate) wash | cleaned and cleaned with alcohol. After forming an acrylic adhesive layer (thickness: 20 micrometers) on the polarizing film surface of the polarizing plate obtained above, it cuts out to the same size (about 150 mm x 200 mm) as the removed polarizing plate, and the visual side of the liquid crystal cell via an adhesive layer. Bonded together. Next, the sheet-shaped adhesive (moisture permeability: 24 g / m <2> / 24 hours, thickness: 25 micrometers) was arrange | positioned at the surface on the opposite side to the liquid crystal cell of a polarizing plate. Here, the sheet was disposed so as to extend-project from all four sides constituting the outer circumference of the polarizing plate. The length of the four extension-protrusions was 5 mm each. The sheet sags by its own weight, adheres directly to the liquid crystal cell, covers the outer circumferential end face of the polarizing plate, and seals it. In this way, the sealing part covering the front surface of the opposite side to the liquid crystal cell of a polarizing plate, and the front surface of an outer peripheral cross section was formed. Then, the cover glass (thickness 1mm) was bonded together through the sealing part (adhesive agent). In addition, the adhesive which comprises a sealing part is polybutene (JX Nikko) with respect to 100 weight part of block copolymers of styrene ethylene propylene copolymer styrene (made by Kuraray, brand name "Sefton 2063", styrene content: 13 weight%). Niseki Energy Co., Ltd., brand name 'Niseki Polybutene HV-300' 10 parts by weight, terpene phenol tackifier (Yashara Chemical Co., Ltd., product name 'YS Polystar-TH130') 40 parts by weight, and aromatic tackifier (Manufactured by Eastman Chemical Co., Ltd., brand name 'Picorastick A5') was blended and produced.

The same polarizing plate was bonded together to the back side of a liquid crystal cell through the acrylic adhesive layer (thickness: 25 micrometers). In this way, a liquid crystal panel was obtained. After placing the obtained liquid crystal panel in the environment of 85 degreeC and 85% RH for 120 hours, it incorporated in the original liquid crystal display device and obtained the liquid crystal display device of this Example. The liquid crystal display substitute of (4) above was used for evaluation of color loss, light leakage and white-blur, and after 120 hours in 85 ° C. and 85% RH, no color loss, light leakage or white-blur was observed. It was confirmed that it was a good black display.

Example 2

A liquid crystal display device and a replacement product were produced in the same manner as in Example 1 except that the sealing portion was formed using an adhesive having a moisture permeability of 6 g / m 2/24 hr (thickness 100 μm). The liquid crystal display substitute of (3) was provided for evaluation of the color loss amount in the same manner as in Example 1. The results are shown in Table 1. In addition, the liquid crystal display substitute of (4) was used for the evaluation of color loss, light leakage and white-blur in the same manner as in Example 1, and the color loss after 120 hours under 85 ° C and 85% RH, It was confirmed to be a good black indication without light leakage, white-blur.

Example 3

A liquid crystal display device and a substitute were produced in the same manner as in Example 1 except that the sealing portion was formed using an adhesive having a water vapor transmission rate of 12 g / m 2/24 hr (thickness 50 μm). The liquid crystal display substitute of (3) was provided for evaluation of the color loss amount in the same manner as in Example 1. The results are shown in Table 1. In addition, the liquid crystal display substitute of (4) was used for the evaluation of color loss, light leakage and white-blur in the same manner as in Example 1, and the color loss after 120 hours under 85 ° C and 85% RH, It was confirmed to be a good black indication without light leakage, white-blur.

Example 4

A liquid crystal display and a substitute were produced in the same manner as in Example 2 except that the cover glass was not disposed. The liquid crystal display substitute of (3) was provided for evaluation of the color loss amount in the same manner as in Example 1. The results are shown in Table 1. In addition, the liquid crystal display substitute of (4) was used for the evaluation of color loss, light leakage and white-blur in the same manner as in Example 1, and the color loss after 120 hours under 85 ° C and 85% RH, It was confirmed that it was a good black display without light leakage, white-blur.

Example 5

In the same manner as in Example 1, a laminate having a configuration of a polarizing film / cycloolefin-based film (protective film) was obtained. Cycloolefin type film (Nippon Xeon make, ZD-12, 23 micrometers) is bonded to the polarizing film surface of the said laminated body through the curable adhesive agent, and a protective film (ZD-12) / polarizing film / protective film (ZF- The polarizing plate which has a structure of 12) was obtained. A liquid crystal display and a substitute were produced in the same manner as in Example 3 except that an acrylic pressure-sensitive adhesive was formed on the surface of the protective film (ZF-12) of the polarizing plate. The liquid crystal display substitute of (3) was provided for evaluation of the color loss amount in the same manner as in Example 1. The results are shown in Table 1. In addition, the liquid crystal display substitute of (4) was used for the evaluation of color loss, light leakage and white-blur in the same manner as in Example 1, and the color loss after 120 hours under 85 ° C and 85% RH, It was confirmed that it was a good black display without light leakage, white-blur.

Example 6

After stretching the PVA resin film (Kuraray Corporation make, brand name 'PE-6000', thickness: 60 µm, average degree of polymerization: 2,400, saponification degree: 99.9 mol%) in the conveying direction by 1.2 times while immersing for 1 minute in a 30 ° C water bath. The film was doubling on the basis of the film (original length) not drawn at all, while being immersed and dyed in a 30 ° C. aqueous solution having an iodine concentration of 0.04 wt% and a potassium concentration of 0.3 wt%. Then, the stretched film was immersed in an aqueous solution at 30 ° C. of 3% by weight of boric acid concentration and 3% by weight of potassium iodide concentration, and further stretched up to three times based on the original length, followed by 4% by weight of boric acid concentration and potassium iodide concentration. While immersing in 5 weight% of 60 degreeC aqueous solution, it extended | stretched further to 6 times based on original length, and dried for 2 minutes at 70 degreeC, and the polarizing film of thickness 23micrometer was obtained. Subsequently, an aqueous PVA-based resin solution (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name 'Gosepimer (registered trademark) Z-200', resin concentration: 3% by weight) was applied to both surfaces of the polarizing film, and a cycloolefin-based film (Nippon Xeon Manufactured by 'Zeonor ZF14', thickness: 13 µm) and a triacetyl cellulose film (KC4UY manufactured by Konica Minolta Co., Ltd.) were bonded to each other and heated for 5 minutes in an oven kept at 60 ° C to obtain a polarizing plate. . The subsequent procedure was carried out similarly to Example 2, and produced the liquid crystal display device and the replacement product. The liquid crystal display substitute of (3) was provided for evaluation of the color loss amount in the same manner as in Example 1. The results are shown in Table 1. In addition, the liquid crystal display substitute of (4) was used for the evaluation of color loss, light leakage and white-blur in the same manner as in Example 1, and the color loss after 120 hours under 85 ° C and 85% RH, It was confirmed that it was a good black display without light leakage, white-blur.

Example 7

The organic EL display device was taken out by disassembling the smartphone (Galaxy-S5) manufactured by Samsung Wireless Co., Ltd., in which a polarizing plate was used as an antireflection application. The polarizing plate affixed on this organic electroluminescence display was peeled off, and the surface from which the polarizing plate was removed was wash | cleaned. On the said removal surface, the polarizing plate (sealing part is formed and put for 120 hours in 85 degreeC and 85% RH environment) used in Example 3 was bonded together, and the organic electroluminescence display was obtained. When the obtained organic electroluminescence display was black-displayed, it was confirmed that it is a favorable black display without color fall-out, light leakage, and white-blur.

Comparative Example 1

70 parts of 2-ethylhexyl acrylate (2EHA), 15 parts of N-vinylpyrrolidone (NVP) and 15 parts of 2-hydroxyethyl acrylate (2HEA), 2,2'-azobisisobuty as a thermal polymerization initiator 0.3 part of ronitrile (AIBN) was added together with 150 parts of ethyl acetate, stirred at 23 ° C. for 1 hour in a nitrogen atmosphere, and then reacted at 58 ° C. for 4 hours, and then at 70 ° C. for 2 hours to prepare an acrylic polymer solution. It was. After preparing the acrylic polymer solution, 0.3 parts by weight of 3-glycidoxypropyltrimethoxysilane (trade name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) and a crosslinking agent were used as the silane coupling agent based on 100 parts of the solid content of the polymer. As 0.4 part of trimethylol propane addition products (brand name: Takeate D110N, Mitsui Chemical Co., Ltd.) of xylylene diisocyanate were added as these, these were mixed uniformly and the acrylic adhesive was produced. The water vapor transmission rate of the obtained adhesive (thickness 100 micrometers) was larger than 1000 g / m <2> / 24hr. A liquid crystal display and a substitute were produced in the same manner as in Example 1 except that the sealing portion was formed using the pressure sensitive adhesive. The liquid crystal display substitute of (3) was provided for evaluation of the color loss amount in the same manner as in Example 1. The results are shown in Table 1. In addition, when the liquid crystal display substitute of (4) was used for evaluation of color loss, light leakage and white-blur in the same manner as in Example 1, light leakage resulting from color loss of the polarizing plate was confirmed.

Comparative Example 2

The liquid crystal display device was carried out in the same manner as in Example 3 except that the sealing portion was formed only on the surface opposite to the liquid crystal cell of the polarizing plate using the sheet-shaped adhesive of the same size as the polarizing plate (that is, the peripheral end face of the polarizing plate was not covered). A replacement was made. The liquid crystal display substitute of (3) was provided for evaluation of the color loss amount in the same manner as in Example 1. The results are shown in Table 1. In addition, when the liquid crystal display substitute of (4) was used for evaluation of color loss, light leakage and white-blur in the same manner as in Example 1, light leakage resulting from color loss of the polarizing plate was confirmed.

Comparative Example 3

The liquid crystal display was carried out in the same manner as in Example 3 except that the sealing portion was formed only on a part of the surface on the opposite side to the liquid crystal cell of the polarizing plate using a sheet-shaped adhesive of a size smaller than that of the polarizing plate (that is, the peripheral end face of the polarizing plate was not covered). The device and replacement were made. The liquid crystal display substitute of (3) was provided for evaluation of the color loss amount in the same manner as in Example 1. The results are shown in Table 1. In addition, when the liquid crystal display substitute of (4) was used for evaluation of color loss, light leakage and white-blur in the same manner as in Example 1, light leakage resulting from color loss of the polarizing plate was confirmed.

[Comparative Example 4]

A liquid crystal display and a substitute were produced in the same manner as in Example 1 except that no sealing portion was formed and no cover glass was disposed. The liquid crystal display substitute of (3) was provided for evaluation of the color loss amount in the same manner as in Example 1. The results are shown in Table 1. In addition, when the liquid crystal display substitute of (4) was used for evaluation of color loss, light leakage and white-blur in the same manner as in Example 1, light leakage resulting from color loss of the polarizing plate was confirmed.

TABLE 1

* The unit of moisture permeability is g / m2 / 24hr.

* The unit of thickness is μm.

* LCD is a liquid crystal display device, and EL is an organic EL display device.

As is clear from Table 1, it can be seen that an image display device capable of maintaining excellent optical properties even in a humidified environment can be obtained by forming a sealing part having a predetermined moisture permeability on the outer peripheral end face of the polarizing plate.

[Industry availability]

The image display device of the present invention is preferably used for TVs, cellular phones, digital cameras, video cameras, portable game machines, car navigation systems, photocopiers, printers, fax machines, watches, microwave ovens, and the like.

10 liquid crystal cell
20 polarizer
21 polarizer
22 protective film
30 seals
40 cover glass
50 pressure sensitive adhesive layer
100 liquid crystal display

Claims (12)

A display cell, a polarizing plate disposed on at least one side of the display cell, and a sealing portion covering a peripheral end face of the polarizing plate;
The polarizing plate comprises a polarizing film composed of a polyvinyl alcohol-based resin film containing iodine,
The moisture permeability of the seal is 300 g / m 2/24 hr or less,
Image display device. The method of claim 1,
And the sealing portion covers the front surface of the side opposite to the display cell of the polarizing plate and the front surface of the peripheral end face. The method according to claim 1 or 2,
The image display apparatus whose thickness of the said sealing part is 10 micrometers-100 micrometers. The method according to any one of claims 1 to 3,
The said display part is comprised from the adhesive agent composition. The method of claim 4, wherein
An image display device, wherein the sealing portion is made of a rubbery adhesive. The method according to any one of claims 1 to 5,
An image display device further comprising a cover glass disposed on a side opposite to the display cell of the polarizing plate. The method according to any one of claims 1 to 6,
The image display apparatus whose color fall-out amount is 100 micrometers or less after holding for 120 hours in 85 degreeC and 85% RH environment. Arranging a polarizing plate on one side of the display cell, and
Forming a sealing portion to cover the peripheral end face of the polarizing plate
Including,
The polarizing plate comprises a polarizing film composed of a polyvinyl alcohol-based resin film containing iodine,
The moisture permeability of the seal is 300 g / m 2/24 hr or less,
The manufacturing method of an image display apparatus. The method of claim 8
And a sealing portion is formed so as to cover the front surface of the side opposite to the display cell of the polarizing plate and the front surface of the peripheral cross section. The method according to claim 8 or 9,
The manufacturing method of the image display apparatus which forms a sealing part by arrange | positioning the sheet | seat which consists of an adhesive agent composition. The method of claim 10,
The size of the said sheet | seat is larger than the said polarizing plate, and the sealing part is formed by arrange | positioning the sheet | seat so that the front surface of the side opposite to the said display cell of the said polarizing plate, and the front surface of the said peripheral end surface is formed. The method according to any one of claims 8 to 11,
And arranging a cover glass on the side opposite to said display cell of said polarizing plate.

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