KR20090129947A - Polarizing plate roll, and polarizing plate roll, polarizing plate and liquid crystal display with pressure sensitive adhesive layer - Google Patents

Abstract

PURPOSE: A polarizing plate roll, a polarizing plate roll in which a pressure sensitive adhesive layer is placed, a polarizing plate and a liquid crystal display device are provided to make the moving direction of a polarizing plate orthogonal to an absorbing axis. CONSTITUTION: A base film(12) is formed by transparent resin selected from a group which includes polypropylene resin, polyethyleneterephthalate resin, polyethylene resin and polyvinylchloride resin. A polarizer(13) is arranged on the base film through a primer layer. The polarizer is composed of poly vinyl alcohol resin containing diachronic dye. In the polarizer, an absorbing axis is located in a direction orthogonal to the moving direction of a roll. The base film is aligned on a plane orthogonal to the moving direction of the roll.

Description

POLARIZING PLATE ROLL, AND POLARIZING PLATE ROLL, POLARIZING PLATE AND LIQUID CRYSTAL DISPLAY WITH PRESSURE SENSITIVE ADHESIVE LAYER}

The present invention relates to a polarizing plate roll for producing a polarizing plate, a polarizing plate roll with a pressure-sensitive adhesive layer, a polarizing plate using the same, and a liquid crystal display device.

Background Art In recent years, low power consumption, low voltage operation, and lightweight, thin liquid crystal displays are rapidly spreading as information display devices such as mobile phones, portable information terminals, computer monitors, and televisions. With the development of liquid crystal technology, various modes of liquid crystal displays have been proposed. For example, there is a liquid crystal mode called IPS (In-plane Switching) mode, Vertical Alignment (VA) mode, TN (Twisted Nematic) mode and the like.

Thus, although the liquid crystal display of various modes exists, the film called a polarizing plate becomes an essential member in almost all.

In a liquid crystal display device, a polarizing plate is an indispensable member in performing display, and in most cases, it is used as a piece of two pieces, since it is arrange | positioned and used on both surfaces of a liquid crystal cell. In the case of such a structure, the polarizing plate arrange | positioned rather than the liquid crystal cell on the viewing side can be called a front polarizing plate, and the polarizing plate arrange | positioned at the backlight side may be called a rear polarizing plate.

Moreover, a polarizing plate is an optical member which has the characteristic that the light after passing it becomes the light which oscillates only in any one specific direction, what is called linear polarization. Although such a kind of absorption type, reflection type, scattering type, etc. exist in such a polarizing plate, in a liquid crystal display, although the absorption efficiency of light is low, the absorption type polarizing plate which is the type with the highest polarization performance is used most frequently.

Polarization performance is compared by the index called polarization degree Py, These are the values defined by following formula (1), and the higher polarization degree has shown that separation of polarization is performed well. Here, Tp and Tc are measured values obtained by polarized ultraviolet visible absorption spectrum measurement by a spectrophotometer, and transmittance | permeability (Tp) measured by the relationship between incident linearly polarized light and parallel nicotine, and transmittance | permeability (Tc) measured by cross nicol Respectively.

Polarization degree Py = 100 × (Tp-Tc) / (Tp + Tc)... … Formula (1)

In addition, the polarizing plate also has an index called a single transmittance (Ty) defined by the following formula (2), and the higher the single transmittance, the better the light utilization efficiency.

Simplex transmittance (Ty) = 0-5 x (Tp + Tc)... … Formula (2)

That is, a polarizing plate with high polarization degree and single transmittance can be said to be a product with good performance.

In recent years, such liquid crystal displays have become popular in the television market, and the size of the screens is being rapidly increased. Until now, the key point in the enlargement of the size of a liquid crystal television was predominantly how big the size of a liquid crystal cell can be made. However, in recent years, a sufficiently large liquid crystal cell having a diagonal exceeding 65 inches has been able to be produced, and this time, a situation has arisen that the size of the polarizing plate is insufficient.

Most of the configurations of the large liquid crystal display are arranged such that the absorption axis of the front polarizing plate is arranged in parallel in the long side direction of the television, and the absorption axis of the rear polarizing plate is orthogonal to the absorption axis of the front polarizing plate. In this case, the short side direction of a rear polarizing plate becomes an absorption axis.

A polarizing plate roll is a polarizing plate wound by roll shape, Usually, it cuts (cuts) to the magnitude | size which needs this polarizing plate roll, and is used for the said use.

A normal polarizing plate roll is produced by stretching in the moving direction of the roll (the winding direction of the roll or the opposite direction), and therefore the absorption axis is necessarily the moving direction of the roll. In such a case, when a chip is cut from a polarizing plate roll and a rear polarizing plate (polarizing plate chip) is made, the long side of a polarizing plate chip is cut out from the width direction of a polarizing plate roll, and the upper limit of the size becomes a quite small thing. On the contrary, when making a front polarizing plate, since the width direction of a polarizing plate roll becomes a short side of a polarizing plate chip, the upper limit of the size to cut out is quite large.

In such a situation, it has responded by widening the width of a polarizing plate roll so far, but in order to achieve it, it is necessary to make an apparatus wide and a disk wide. Both of them are difficult to widen the width of the polarizing plate roll when either of the members constituting the device or the polarizing plate cannot take the wide correspondence. Moreover, since there exist limits, such as the handling property of the polarizing plate roll in manufacturing, it is said that it is an upper limit which can respond to the polarizing plate of about 65 inches in diagonal size as a development.

On the other hand, about the 70-inch or more liquid crystal display, although the method of using two or more rear polarizing plates is also employ | adopted, it is a phenomenon that after all, the display quality of a joint part becomes bad.

As described above, a large polarizing plate for a large-sized liquid crystal television can be produced by using a wide member film or a wide polarizing plate line. However, the widening of the film has limitations in terms of handling properties and the like. There is a problem that it is difficult to obtain a polarizing plate for display.

Among these, in order to produce a rear polarizing plate in the same size as a front polarizing plate, what is necessary is just to be able to obtain that the absorption axis of a polarizing plate roll is orthogonal to the moving direction of a roll. In this case, since a rear polarizing plate cuts out in the same direction as a front polarizing plate, considerable enlargement can be achieved.

On the other hand, it is also known to manufacture a thin polarizing plate by forming the application layer of polyvinyl alcohol-type resin on the base film which consists of thermoplastic resins, extending | stretching for every base film, and dyeing. For example, in JP-A-2000-338329 (Patent Document 1, in particular, see Claim 2), a polyvinyl alcohol-based resin layer is formed on one surface of the thermoplastic resin film at a thickness of 6 µm or more and 30 µm or less, After extending | stretching in the lamination | stacking state, it is dyeing and providing a polarizing ability to a polyvinyl alcohol-type resin layer, and using it as a thin polarizing plate is described.

For example, Japanese Patent Laid-Open No. 2001-343521 (Patent Document 2) discloses a thickness of 10 having a polyvinyl alcohol-based resin as a main component for the purpose of providing a polarizing plate using a polarizing film that is thin and has a small shrinkage stress. The polarizing plate by which a protective film is bonded by at least one surface of the polarizing film of micrometers or less is disclosed. In addition, JP 2001-343522 A (Patent Document 3), similarly, has as its main component a polyvinyl alcohol-based resin uniaxially stretched for the purpose of providing a polarizing film that is thin and has a small shrinkage stress, The polarizing film whose product dxe of the film thickness d (micrometer) and draw ratio e (times) of a film is 30 or less is disclosed. These patent documents 2 and 3 further describe the effect of extending | stretching the laminated | multilayer film by which polyvinyl alcohol-type resin was apply | coated on the base resin film by the tenter method to the lateral direction uniaxial.

An object of the present invention is to provide a polarizing plate roll in which the moving direction of the polarizing plate and the absorption axis are orthogonal.

The polarizing plate roll of this invention,

A base film, a primer layer formed of a transparent resin selected from the group consisting of polypropylene resin, polyethylene terephthalate resin, polyethylene resin and polyvinyl chloride resin;

A polarizing plate roll comprising a polarizer disposed on the base film through the primer layer and composed of a polyvinyl alcohol resin containing a dichroic dye,

The polarizer is in the direction whose absorption axis is orthogonal to the movement direction of a roll, the base film is in-plane oriented in the direction orthogonal to the movement direction of a roll, and (DELTA) n defined by the following formula is 0.01 or more:

Δn = n _x -n _y

In the above formula, n _x represents a refractive index in a direction in which the refractive index becomes maximum in the film plane, and n _y represents a refractive index in a direction orthogonal to the direction of n _{x in} the film plane.

In the polarizing plate roll of the present invention, the polyvinyl alcohol resin preferably has a saponification degree of 98 mol% or more and a polymerization degree of 1000 or more.

In the polarizing plate roll of this invention, it is preferable that a primer layer is a transparent resin layer formed from the composition containing a modified polyvinyl alcohol resin and a crosslinking agent.

It is preferable that the transparent protective layer of the polarizing plate roll of this invention is arrange | positioned through the adhesive bond layer on the surface of the polarizer side of a polarizing plate roll further.

This invention also provides also about the polarizing plate roll with a pressure-sensitive adhesive layer in which the pressure-sensitive adhesive layer is formed in at least one surface of the polarizing plate roll of this invention mentioned above.

Moreover, this invention provides also about the polarizing plate which chip-cuts the polarizing plate roll with the pressure-sensitive adhesive layer of this invention mentioned above.

The present invention also provides a liquid crystal display device comprising a polarizing plate having a liquid crystal cell and the pressure-sensitive adhesive layer of the present invention described above, wherein the pressure-sensitive adhesive layer of the polarizing plate is bonded to the liquid crystal cell.

According to the polarizing plate roll of this invention in which the movement direction of a polarizing plate and an absorption axis orthogonally cross, since a rear polarizing plate can be chip-cutted by making the width direction of a polarizing plate roll into a short side, the size of the rear polarizing plate cut out The upper limit can be taken quite large.

1: A is a perspective view which shows typically the polarizing plate roll 1 of a preferable example of this invention, and FIG. 1B is the polarizing plate (polarizing plate chip) 11 of this invention chip-cut from the polarizing plate roll 1 shown in FIG. 1A. It is an exploded perspective view schematically showing). The polarizing plate roll 1 of this invention is a polarizing plate roll whose absorption axis is a direction orthogonal to the moving direction of a roll, The polarizer which contains a dichroic dye in polyvinyl alcohol resin on the base film formed from transparent resin is a primer It is to have a basic structure disposed through the layers.

As a base film used for the polarizing plate roll of this invention, in order to orientate polyvinyl alcohol resin in the direction orthogonal to the movement direction of a roll, and to raise the phase difference value ((DELTA) n per unit thickness, it is a polyvinyl alcohol resin which becomes a polarizer. It should be able to process, such as extending | stretching a layer for every base film. It is because the polyvinyl alcohol resin which becomes a polarizer in the polarizing plate roll of this invention increases (DELTA) n of a dichroic dye as the (DELTA) n is high, and the performance as a polarizing plate obtained from this polarizing plate roll improves. As a base film used for this invention, the film which can be extended | stretched with high magnification in the direction perpendicular | vertical to the moving direction of a roll is preferable. In view of the above, in the present invention, a polypropylene resin, a polyethylene terephthalate resin, a polyethylene resin, and a polyvinyl chloride resin, which are crystalline resins that can be stretched at high magnification, are formed of a transparent resin. A base film is used and is usually flat. Among them, polyolefins and the like are preferable because of the low price of the resin. Moreover, it is preferable that it is a copolymer etc. which can be optimized, such as easiness of extending | stretching and strength as a protective film by optimizing the composition ratio. From these viewpoints, the base film formed from the above-mentioned propylene resin which is a propylene ethylene copolymer is preferable.

As a method of extending | stretching a polyvinyl alcohol resin used as a polarizer for every base film, the extending | stretching method represented by the fixed end uniaxial stretching typically represented by a tenter type stretching machine etc., or the pin tenter which can overfeed shrinkage in the moving direction is mentioned. Can be. By extending | stretching by such a method, the base film oriented in-plane in the direction orthogonal to the moving direction of a roll used for the polarizing plate roll of this invention can be obtained.

In addition, when performing the said extending | stretching process, (DELTA) n of the layer of the polyvinyl alcohol resin stuck to a base film depends largely on the method by which a base film is extended. That is, when the orientation state of a base film is good, it can be said that the orientation state of the polyvinyl alcohol resin arrange | positioned through a primer layer on a base film is also good, so that (DELTA) n of the base film in the polarizing plate roll of this invention is more preferable. Do. In the polarizing plate roll of this invention, the base film whose value of (DELTA) n is 0.01 or more (more preferably 0.02 or more, more preferably 0.25 or more) is used from a viewpoint which can obtain the polarizing film of the relationship of favorable transmittance | permeability and polarization degree.

However, (DELTA) n of the base film here is defined by the anisotropy of the in-plane refractive index, and is computed based on the front side retardation measured by birefringence measuring apparatus KOBRA-WPR (made by Oshi Measurement Instruments Co., Ltd.) etc. Refers to the retardation value per unit thickness defined by the equation:

Δn = (n _x -n _y ) = R _o / d

In the above formula, n _x represents a refractive index in the direction in which the refractive index becomes maximum in the film plane, and n _y represents a refractive index in a direction orthogonal to the direction of n _{x in} the film plane. In addition, R _o represents frontal retardation (nm), and d represents film thickness (nm).

In addition, about an actual polarizing plate roll, in order to measure (DELTA) n of a base film, a polarizer is peeled from a base film and only a base film is measured with the said birefringence measuring apparatus. As a method of peeling a polarizer, the method etc. which take off from a base film after swelling polyvinyl alcohol resin which is a polarizer with 60 degreeC-80 degreeC warm water, etc. can be employ | adopted, for example.

In the polarizing plate roll of this invention, the polarizer comprised from polyvinyl alcohol resin containing a dichroic dye is used. As shown in FIG. 1A, the polarizer in the polarizing plate roll 1 of this invention exists in the direction whose absorption axis B orthogonally crosses the moving direction A of a polarizing plate roll. Examples of the polyvinyl alcohol resins include copolymers of vinyl acetate and other monomers copolymerizable with vinyl acetate and other monomers (e.g. unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, etc.) other than polyvinyl acetate which is a homopolymer of vinyl acetate. What was obtained by saponification can be used.

Moreover, since the polyvinyl alcohol resin used for the polarizer in this invention is excellent in water resistance, it is preferable that saponification degree is 98.0 mol% or more, and it is more preferable that it is 99.0 mol% or more. In addition, from the viewpoint of excellent water resistance, the polyvinyl alcohol resin used for the polarizer in the present invention is preferably 1000 or more, and more preferably 1500 or more. As a polyvinyl alcohol resin having such a saponification degree and a polymerization degree, specifically, PVA117 (saponification degree: 98.0 mol%-99.0 mol%, polymerization degree: about 1700) [Kuraraye Co., Ltd.], PVA117 (saponification degree: 99.3) Mol% or more, polymerization degree: about 1700) [Kurarese Co., Ltd.], PVA124 (saponification degree: 98.0 mol%-99.0 mol%, polymerization degree: about 2400) [Kurarese Co., Ltd., Kurarevinylone VF-PS # Commercially available products, such as 7500 (saturation degree: 99.3 or more and polymerization degree: about 2400), can be used suitably.

As a dichroic dye to be contained in polyvinyl alcohol resin, iodine, a dichroic dye, etc. are used, for example. Dichroic dyes include, for example, dichroic direct dyes made of disazo compounds such as C.I, DIRECT RED 39, dichroic direct dyes made of compounds such as tris azo and tetrakis azo.

As for the polarizing plate roll of this invention, a primer layer is interposed between a base film and a polarizer. This primer layer is provided in order to improve the adhesiveness between a polarizer and a base film, and when there is no primer layer, when dyeing a polarizer, it is easy to produce the problem that a polarizer peels from a base film.

Although it does not restrict | limit as a primer layer, The production of a solution becomes easy by using polymodified vinyl alcohol with high solubility in water, and there exists an advantage that applicability | paintability is favorable by obtaining the favorable aqueous solution of low viscosity. Moreover, by using it in combination with this crosslinking agent, favorable water resistance can be obtained after film-forming. From these viewpoints, it is preferable that it is a transparent resin layer formed from the composition containing a modified polyvinyl alcohol resin and a crosslinking agent. The modified polyvinyl alcohol resin refers to a polyvinyl alcohol resin to which ionic modifications such as cation modification and anion modification are applied, and specifically, KL-506, which is a carboxy-modified polyvinyl alcohol resin, sold by Kuraray Co., Ltd. And the high-cephamer Z200 (sold by Nippon Synthetic Chemical Co., Ltd.), which is an acetacetyl-modified polyvinyl alcohol resin.

Examples of the crosslinking agent used for the primer layer include polyamide epoxy resins, diketones such as glutaraldehyde and glyoxal, methylolated melamine resins, and water-soluble metal complexes such as zirconyl nitrate and titanium chelate. In order to obtain the favorable adhesiveness of the polyamide epoxy resin is preferable. As the polyamide epoxy resin, one obtained by reacting epichlorohydrin with a polyamide polyamine obtained by, for example, a reaction of a polyalkylene polyamine such as diethylenetriamine or triethylenetetramine with a dicarboxylic acid such as adipic acid can be used. Specific examples thereof include Sumirez Resin 650 (30) (sold by Sumitomo Chemical Chemtex Co., Ltd.).

The polarizing plate roll of this invention as mentioned above can be produced by the method containing the process of the following (A)-(C), for example.

(A) Process of apply | coating polyvinyl alcohol resin used for a polarizer on a base film through a primer layer, and obtaining a laminated film,

(B) Process of obtaining the oriented film by aligning the laminated film obtained at process (A) by the tenter etc. by fixed-terminal transverse direction, and obtaining it,

(C) process of dyeing the alignment film obtained at process (B).

At the process of said (A), the composition (PVA aqueous solution for primers) containing the above-mentioned modified polyvinyl alcohol resin and a crosslinking agent is first apply | coated on the base film which corona-discharge-processed previously, and it formed poly An aqueous solution of vinyl alcohol resin (PVA aqueous solution for polarizer) is applied. At this time, the aqueous solution of polyvinyl alcohol resin can be produced by the following method. First, polyvinyl alcohol is swelled in water at room temperature. Thereafter, the water temperature is heated to 60 ° C or higher to sufficiently dissolve the polyvinyl alcohol resin. The aqueous solution of the obtained polyvinyl alcohol resin may be applied onto the base film with a coating machine having a coating head with a temperature adjustment function as it is, and once it is an aqueous solution of polyvinyl alcohol resin cooled to room temperature, the general coating agent at room temperature You may apply | coat on a base film.

The method of coating the aqueous solution of the polyvinyl alcohol resin is not particularly limited, and generally, a coating method such as a gravure coating method, a die coating method, a comma coating method, a lip coating method and the like can be given.

In the process of said (B), although the lateral direction extending | stretching can be performed for every base film, the laminated | multilayer film obtained at the process of said (A) is not restrict | limited about the method of extending | stretching.

For example, the fixed end lateral uniaxial stretching represented by a tenter etc. may be sufficient, and the overfeed lateral stretching which transversely stretches while shrinking a moving direction with a pin tenter etc. may be sufficient.

The dyeing method in the step (C) is not limited, but can be carried out under general conditions. For example, the orientation film may be a method of dipping in order in a swelling bath made of warm water at about 40 ° C. to 80 ° C., a dyeing bath made of an aqueous solution of iodine / potassium iodide, and a crosslinking bath formed by dissolving boric acid in hot water at 50 ° C. to 90 ° C. have.

Among these, the dye bath may be formed by dissolving dichroic dyes other than iodine.

As for the polarizing plate roll of this invention, it is preferable that the transparent protective layer is arrange | positioned through the adhesive bond layer on the surface of the polarizer side of a polarizing plate roll. Examples of the transparent protective layer include cycloolefin resin films, cellulose acetate resin films such as triacetyl cellulose and diacetyl cellulose, polyester resin films such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate, and polycarbonates. The film widely used conventionally in the art, such as a resin film, an acrylic resin film, and a polypropylene resin film, is mentioned.

Cycloolefin resins that can be used for the transparent protective layer in the present invention are suitable commercially available products such as Topas (manufactured by Ticona), Aton (manufactured by JSR Corporation), Zeonor (manufactured by Japan Xion Corporation). , ZEONEX (manufactured by Japan Xeon Co., Ltd.), Apel (manufactured by Mitsui Chemicals Co., Ltd.), and the like can be suitably used. When forming such a cycloolefin resin into a film, well-known methods, such as a solvent casting method and a melt-extrusion method, are used suitably. Moreover, the film of cycloolefin resin previously formed into a film, such as Essina (made by Sekisui Chemical Co., Ltd.), SCA40 (made by Sekisui Chemical Co., Ltd.), and a Zeonoa film (made by Optes) You may use commercially available products.

Moreover, as a cellulose acetate-type resin film which can be used for the protective film in this invention, a suitable commercial item, for example, FujiTak TD80 (made by Fujifilm Co., Ltd.), FujiTak TD80UF (made by Fujifilm Co., Ltd.), FujiTak TD80UZ Fuji Film Co., Ltd., FujiTak TD40UZ (Fujifilm Co., Ltd. product), KC8UX2M (Konica Minolta Opt Co., Ltd. product), KC4UY (Konica Minolta Opt Co., Ltd. product) etc. can be used suitably.

As an adhesive agent used for joining a polarizer and a transparent protective layer, the thing of the water system, ie, what melt | dissolved the adhesive component in water, or disperse | distributed to water from a viewpoint of thinning an adhesive bond layer is mentioned. For example, the composition using polyvinyl alcohol-type resin or urethane resin as a main component is mentioned as a preferable adhesive agent.

When using polyvinyl alcohol-type resin as a main component of an adhesive agent, this polyvinyl alcohol-type resin is a part saponified polyvinyl alcohol, fully saponified polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, acetacetyl-group modified polyvinyl alcohol, methylol group Modified polyvinyl alcohol-based resins such as modified polyvinyl alcohol and amino group-modified polyvinyl alcohol may be used. In this case, an aqueous solution of polyvinyl alcohol-based resin is used as the adhesive. The concentration of the polyvinyl alcohol-based resin in the adhesive is usually 1 to 10 parts by weight, preferably 1 to 5 parts by weight with respect to 100 parts by weight of water.

In order to raise adhesiveness, it is preferable to add curable components, such as glyoxal and a water-soluble epoxy resin, and a crosslinking agent to the adhesive agent which consists of aqueous solution of polyvinyl alcohol-type resin. As a water-soluble epoxy resin, the polyamide obtained by making epichlorohydrin react with the polyamide amine obtained by reaction of polyalkylene polyamines, such as ethylene triamine and triethylene tetramine, and dicarboxylic acids, such as adipic acid, for example. Polyamine epoxy resin can be used suitably. Commercially available products of such polyamide polyamine epoxy resins include Sumirez Resin 650 (manufactured by Sumitomo Chemical Chemtex Co., Ltd.), Sumirez Resin 675 [manufactured by Sumitomo Chemical Chemtex Co., Ltd.], WS-525 [manufactured by Japan PMC Co., Ltd.] ], And the like. The addition amount of these curable components and a crosslinking agent (when added together) is 1-100 weight part normally with respect to 100 weight part of polyvinyl alcohol-type resins, Preferably it is 1-50 weight part.

Moreover, this invention provides also about the polarizing plate roll with a pressure-sensitive adhesive layer in which the pressure-sensitive adhesive layer is formed in at least one surface of the polarizing plate roll of any one of the above-mentioned this invention. As a pressure-sensitive adhesive agent (adhesive) used for such a pressure-sensitive adhesive layer, conventionally well-known suitable adhesives can be used without a restriction | limiting, For example, an acrylic adhesive, a urethane type adhesive, a silicone type adhesive etc. are mentioned. Especially, an acrylic adhesive is used preferably from a viewpoint of transparency, adhesive force, reliability, rework property, etc. The pressure-sensitive adhesive layer can be provided by using a method such as using a pressure-sensitive adhesive in the form of an organic solvent solution, for example, by applying a die coater, a gravure coater, or the like on a base film, followed by drying. It can also be provided by the method of transferring the sheet-like adhesive formed on a film (called a cerate film) to a base film. Although there is no restriction | limiting in particular also about the thickness of a pressure-sensitive adhesive layer, It is preferable to exist in the range of 2 micrometers-40 micrometers generally.

This invention also provides about the polarizing plate (polarizing plate chip) which chip-cuts the polarizing plate roll with the pressure-sensitive adhesive layer of this invention mentioned above. FIG. 1: B is an exploded perspective view which shows typically the polarizing plate (polarizing plate chip) 11 of this invention chip-cut from the polarizing plate roll 1 shown in FIG. 1A. The polarizing plate 11 of the present invention has a structure in which a polarizer (polarizing film) 13 is laminated on a base film 12 via a primer layer 14, for example, as shown in FIG. 1B. The polarizing plate 11 of the example shown in FIG. 1B is chip-cut in rectangular shape, and its short side direction becomes an absorption axis, and can be used suitably as a rear polarizing plate arrange | positioned at the backlight side in a liquid crystal display.

The present invention also provides a liquid crystal display device comprising a liquid crystal cell and the polarizing plate of the present invention described above, wherein the pressure-sensitive adhesive layer of the polarizing plate is bonded to the liquid crystal cell. In the liquid crystal display device of the present invention, for parts other than the above-described features, an appropriate configuration of a conventionally known liquid crystal display device can be adopted, and the configuration requirements that the liquid crystal display device usually includes other than the liquid crystal panel (light diffuser plate, Backlight, etc.) is not limited.

Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited to these.

<Examples 1-7, Comparative Examples 1-3>

(Production of PVA Aqueous Solution for Primer)

To 100 parts by weight of water, 1.5 parts by weight of acetacetyl-modified polyvinyl alcohol resin (gocefimer Z200, sold by Nippon Synthetic Chemical Co., Ltd.) was mixed. After swelling at room temperature for a while, the temperature was raised to 90 ° C and stirred for 1 hour. While dissolving the polyvinyl alcohol resin to obtain a uniform aqueous solution. To this polyvinyl alcohol resin, 1.25 parts by weight of a polyamide epoxy resin [Sumirez Resin 650 (30), manufactured by Sumitomo Chemical Chemtex Co., Ltd.] was added to obtain a PVA aqueous solution for primers.

(Production of PVA Aqueous Solution for Polarizer)

Water was added to the resin pellet of the polyvinyl alcohol shown in following Table 1 sold by Kuraray Co., Ltd., and it left still overnight and swelled. After adjusting solid amount so that the viscosity of the completed aqueous solution might be set to about 1200 mPa * sec, it heated up to 90 degreeC, stirred for 4 hours, and dissolved the polyvinyl alcohol resin pellet. Next, it cooled to room temperature and obtained the aqueous solution. However, in Table 1, since Kureray vinylon VF-PS # 7500 is not sold in resin pellets, the obtained film sheet is finely chopped to about 2 cm on all sides, immersed in hot water of about 40 ° C, washed with glycerin, and then 70 ° C. It was used after vacuum drying for 4 hours.

(Coating of primer layer)

Irradiation amount continuously 280 W · min / to this disk surface using the 100-micrometer-thick polypropylene resin raw material film formed from Sumitomo noble W151 (made by Sumitomo Chemical Co., Ltd.) which is a propylene ethylene copolymer. Corona discharge treatment was performed under the condition of m ² . Furthermore, the PVA aqueous solution for primers produced above was continuously coated by the microgravure method on this disk surface, and the base film with a primer layer was obtained. When the thickness of the base film before application | coating and the thickness of the base film with a primer layer after application | coating were measured, what was 100.0 micrometers-100.3 micrometers before application becomes about 100.1 micrometers-100.5 micrometers after application | coating, and a primer layer is 0.1 micrometer- It turned out that it is about 0.5 micrometer in thickness.

(Application of PVA Aqueous Solution for Polarizer)

On the primer layer of the base film with the primer layer obtained above, four kinds of the above-mentioned PVA aqueous solution for polarizers were apply | coated continuously using the die-coating method so that the thickness after drying may be set to 15 micrometers, and a polyvinyl alcohol resin layer The polypropylene resin raw roll (four kinds) which there was was obtained.

(Extension)

The obtained polypropylene-based resin rolls having four kinds of polyvinyl alcohol resin layers were uniaxially stretched in the fixed end transverse direction at a predetermined magnification shown in Table 2 by a tenter method continuously under conditions of 131 ° C. and 121 ° C. stretching. And the film orientated in the width direction were obtained. As shown in Table 2, since PVA117H and PVA124 changed draw ratio and performed some experiment, ten types of films were obtained in total here.

(dyeing)

The obtained 10 types of films were dyed by the following methods, respectively.

(1) The film is swelled by immersion in hot water at 60 ° C. for 90 seconds.

(2) Subsequently, the iodine is adsorbed to polyvinyl alcohol by immersion in an iodine / potassium iodide aqueous solution (28 ° C.) for a residence time of 300 seconds.

(Composition of Aqueous Iodine / Potassium Iodide)

100 parts by weight of water

0.6 parts by weight of iodine

5 parts by weight of potassium iodide

(3) Furthermore, polyvinyl alcohol is bridge | crosslinked by immersing in boric acid / potassium iodide aqueous solution (76 degreeC) of the following composition for 600 second residence time.

(Composition of boric acid / potassium iodide aqueous solution)

100 parts by weight of water

15 parts by weight of boric acid

9 parts by weight of potassium iodide

(4) It is immersed in cold water of 6 degreeC for 2 second residence time, and wash | cleans excess chemical agent on the film surface.

(5) It is dried with a residence time of 300 seconds in a 50 ° C. drying furnace.

[Evaluation test]

About the polarizing plate rolls of Examples 1-7 and Comparative Examples 1-3 obtained as mentioned above, the polarization degree Py and a single transmittance (Py) were measured using the ultraviolet-visible spectrophotometer V-7100 (made by Japan Spectrometry). Ty) was measured. Moreover, after the Δn of the base film in the polarizing plate rolls of Examples 1 to 7 and Comparative Examples 1 to 3 swelled the polarizer with hot water at 80 ° C., the phase difference measuring device KOBRA-WPR [Oshi Measuring Instruments Co., Ltd. ].

It was 20 micrometers when the polarizer was swollen with 80 degreeC warm water and peeled off from the polarizing plate roll obtained in Example 1, and the thickness of the base film was measured. From this, the thickness of the polarizer could be expected to be 3 µm thick, and it was found that the ratio before stretching was approximately the same.

Base film thickness / polarizer thickness (before stretching) = 100/15 = 6.67

Base film thickness / polarizer thickness (after stretching) = 20/3 = 6.67

<Comparative Example 4>

In the same manner as in Example 1, except that the corona discharge treatment was applied to the surface of the polypropylene-based resin master roll, and then the PVA aqueous solution for polarizer was applied without forming a primer layer. Although the polarizing plate roll was going to be produced, since there was no primer layer, the polarizer peeled from the base film at the time of dyeing, and the polarizing plate was not obtained.

The disclosed embodiments and examples are to be considered in all respects only as illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that the present invention cover all modifications within the meaning and range equivalent to the scope of the claims.

1: A is a perspective view which shows typically the polarizing plate roll 1 of an example in which this invention is preferable.

FIG. 1B is an exploded perspective view schematically showing the polarizing plate (polarizing plate chip) 11 of the present invention chip cut from the polarizing plate roll 1 shown in FIG. 1A.

<Code description>

1: polarizing plate roll, 11: polarizing plate, 12: base film, 13: polarizer, 14: primer layer.

Claims (7)

A base film formed of a transparent resin selected from the group consisting of polypropylene resin, polyethylene terephthalate resin, polyethylene resin and polyvinyl chloride resin, A primer layer, and A polarizer disposed on the base film through the primer layer and composed of a polyvinyl alcohol resin containing a dichroic dye. As a polarizing plate roll comprising: The said polarizer is in the direction whose absorption axis is orthogonal to the moving direction of a roll, The base film is in-plane oriented in the direction orthogonal to the moving direction of a roll, and the polarizing plate roll whose (DELTA) n defined by the following formula is 0.01 or more: Δn = n _x -n _y In the above formula, n _x represents a refractive index in the direction in which the refractive index becomes maximum in the film plane, and n _y represents a refractive index in a direction orthogonal to the direction of n _{x in} the film plane. The polarizing plate roll according to claim 1, wherein the polyvinyl alcohol resin has a saponification degree of 98 mol% or more and a polymerization degree of 1000 or more. The polarizing plate roll of Claim 1 or 2 whose primer layer is a transparent resin layer formed from the composition containing a modified polyvinyl alcohol resin and a crosslinking agent. The polarizing plate roll of Claim 1 or 2 in which the transparent protective layer is arrange | positioned through the adhesive bond layer on the surface of the polarizer side of a polarizing plate roll. The polarizing plate roll with a pressure-sensitive adhesive layer in which the pressure-sensitive adhesive layer is formed on at least one surface of the polarizing plate roll of claim 1. The polarizing plate which chip-cuts the polarizing plate roll with a pressure-sensitive adhesive layer of Claim 5. A liquid crystal display device comprising a polarizing plate having a liquid crystal cell and the pressure-sensitive adhesive layer of claim 6, wherein the pressure-sensitive adhesive layer of the polarizing plate is bonded to the liquid crystal cell.

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