JPH09197127A - Polarizing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing plate excellent in polarizing characteristics, excellent also in durability at high temp. and humidity and having various functions. SOLUTION: This polarizing plate consists of a functional layer, a protective layer, a polarizing film and a protective layer laminated in order. The polarizing film is a PVA-base polarizing film satisfying the inequality (b1 /a1 )/(b0 /a0 )>0.7 when spectral intensities of the film at 1-5cm<-1> and 157cm<-1> at the time of irradiation with Ar<+> laser light having 514.5nm excitation wavelength by a Raman spectroscopic method after the film is allowed to stand for 200hr in an atmosphere at 80 deg.C and 90% RH are represented by a1 and b1 , respectively, and such spectral intensities before the film is allowed to stand are represented by a0 and b0 , respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizing plate provided with various functional layers, and more particularly to a polarizing plate with a functional layer having excellent optical properties and excellent durability under high temperature and high humidity conditions. It is a thing.

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have been used in desk-top electronic calculators, electronic timepieces, word processors, measuring instruments such as automobiles and machines, and accordingly, a polarizing film or protective layers provided on both sides of the polarizing film. The demand for polarizing plates is also increasing. In particular, a polarizing film having a high degree of polarization and a high degree of transparency and excellent durability is required for accurate instruments.

At present, one of the known typical polarizing films is a polyvinyl alcohol film dyed with iodine, which is formed by uniaxially stretching an aqueous solution of polyvinyl alcohol. It is manufactured by dyeing or dyeing with iodine and then uniaxially stretching, and then preferably subjected to a durability treatment with a boron compound.

[0004]

However, in the case of the conventional polyvinyl alcohol type polarizing film as described above,
Although good enough polarization performance can be obtained,
With the recent advancement of technology, further optical performance is required. Further, the above polarizing film is not yet satisfactory in durability at high temperature and high humidity, and there is still room for improvement in polarizing plates having various functional layers.

[0005]

The inventor of the present invention has conducted extensive studies to solve such a problem, and as a result, the functional layer / protective layer /
In a polarizing plate having a structure of polarizing film / protective layer,
Apply 2 to the polarizing film in an atmosphere of 80 ° C. and 90% RH.
Excitation wavelength 51 by Raman spectroscopy after standing for 00 hours
When the spectral intensity of 105 cm ^-1 and 157cm ^-1 at Ar ⁺ laser irradiation 4.5nm and a ₁ and b _1, respectively, to the spectral intensity before the polarizing film left processing and a ₀ and b _0, respectively, (B ₁ / a ₁ ) / (b ₀ /
A polarizing plate using a polyvinyl alcohol-based polarizing film satisfying a ₀ )> 0.7 has excellent polarization performance and excellent durability at high temperature and high humidity, and further (b ₀ / a ₀ ). <
It was found that the effect of the present invention can be remarkably obtained when 1.1 is satisfied, and the present invention has been completed.

Incidentally, the above polarizing film at 80 ° C. and 90%
When left to stand for 200 hours in an atmosphere of RH, cellulose triacetate whose surface was alkali-saponified and neutralized by using an aqueous polyvinyl alcohol solution (coating dry thickness 0.01 μm) as an adhesive on both surfaces of the polarizing film before the treatment A laminate having a film (80 μm) attached is used as a sample,
After the sample was left standing under the above conditions, the sample was immersed in cyclohexanone for 12 hours at 20 ° C. to dissolve and completely remove the cellulose triacetate film on both sides,
The spectral intensity of the polarizing film alone after the surface-adhering solvent was completely removed by air drying or the like was taken as the spectral intensity after the standing treatment. (In removing the cellulose triacetate film, a method of physically removing the film by scraping it off is also possible.) In addition, in the measurement of the spectral intensity of the polarizing film before the above standing treatment, the production of the polarizing film Due to the circumstances
When a protective layer such as a cellulose triacetate film is laminated on the polarizing film, the protective layer is peeled off by the method described above and the spectral intensity of the polarizing film alone is measured. (When the protective layer is an acrylic resin, a solvent such as acetone, benzene, or toluene may be used.) In the present invention, a polarizing film having protective layers on both sides is referred to as a "polarizing plate". To call.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The polarizing film of the present invention is a uniaxially stretched film of polyvinyl alcohol-based resin film, and the polyvinyl alcohol-based resin is usually produced by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate, but the present invention is not necessarily limited to this. However, small amounts of unsaturated carboxylic acids (including salts, esters, amides, nitriles, etc.), olefins,
It may contain a component copolymerizable with vinyl acetate, such as vinyl ethers and unsaturated sulfonates. Further, a polyvinyl butyral resin obtained by reacting a polyvinyl alcohol resin with an aldehyde in the presence of an acid, a so-called polyvinyl acetal resin such as a polyvinyl formal resin, and other polyvinyl alcohol resin derivatives are also included, but are not limited thereto. . Of these, PVA having a high degree of saponification and a high degree of polymerization is preferable because it has good heat resistance. That is, the saponification degree is preferably 95 mol% or more, more preferably 97 mol% or more, and particularly 99 mol% or more.
It is more than mol% and the degree of polymerization is preferably 1000 or more, more preferably 1000 to 10000, especially 2000 to 50.
No. 00 is practical, but the present invention is not limited thereto.

As a method for producing the above-mentioned polarizing film, a stock solution of a polyvinyl alcohol resin dissolved in water or an organic solvent is cast to form a film, which is stretched and dyed with iodine, or stretched and dyeed simultaneously, or iodine is used. A method of treating with a boron compound after dyeing and stretching is mentioned, but in the present invention, stretching is preferably performed during the treatment with the boron compound. As the solvent used in preparing the stock solution, for example, water is of course used,
Dimethylsulfoxide (DMSO), N-methylpyrrolidone, glycerin, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyhydric alcohols such as trimethylolpropane, amines such as ethylenediamine, diethylenetriamine and mixtures thereof Used.

The organic solvent may contain a small amount of water, for example, 5 to 30% by weight. The practical concentration of polyvinyl alcohol in the stock solution is 4 to 50% by weight. The undiluted solution for forming a polyvinyl alcohol film obtained by using the solvent is formed by any method such as a casting method and an extrusion method. The film-forming method is a dry / wet film-forming method, that is, the solution is once discharged from the mouth slit into the air or into an inert atmosphere such as nitrogen, helium, or argon, and then introduced into a coagulation bath for unstretching. Form a film. Alternatively, the film-forming solution discharged from the spinneret may be introduced into a coagulation bath after the solvent is partially dried on a roller or a belt conveyor or the like.

The solvent used in the coagulation bath is miscible with the solvent of the polyvinyl alcohol resin, and examples thereof include alcohols such as methanol, ethanol, propanol and butanol, acetone, benzene and toluene. The polyvinyl alcohol unstretched film obtained as described above is then stretched and dyed.

The dyeing of the film, that is, the adsorption of the polarizing element is performed by bringing the liquid containing the polarizing element into contact with the film. Usually, an aqueous solution of iodine-potassium iodide is used. The concentration of iodine is 0.1 to 2 g / l, the concentration of potassium iodide is 10 to 50 g / l, and the weight ratio of iodine / potassium iodide is 20 to 100. Appropriate. Dyeing time is 3
Practical use is about 0 to 480 seconds. A small amount of an organic solvent compatible with water other than the water solvent may be contained.
Moreover, you may make a dye contain as needed.

As the contact means, any means such as dipping, coating and spraying can be applied. The dyed film is
Then, it is stretched in a boron compound. It is desirable that the stretching is performed in the uniaxial direction by 2.0 times or more, preferably 3.0 to 7.0 times. At this time, slight stretching (extending to the extent of preventing shrinkage in the width direction or more) may be performed in the direction perpendicular to the above. Boric acid and borax are practical as boron compounds. The boron compound is used in the form of an aqueous solution or a water-organic solvent mixture at a concentration of about 0.5 to 2 mol / l, and it is practically desirable to allow a small amount of potassium iodide to coexist in the solution.

As the treatment method, the dipping method is preferable, but of course, the coating method and the spraying method can also be carried out. If necessary, a stretching operation may be performed during the treatment or after the treatment. The treatment with the boron compound can be replaced by adding a boron compound to a polyvinyl alcohol-based resin solution in advance to form a film. In this way,
The iodine-dyed polyvinyl alcohol-based polarizing film used in the present invention can be obtained. In the present invention, the film is used in an atmosphere of 80 ° C. and 90% RH.
Excitation wavelength by Raman spectroscopy after standing for 514 hours 514.
105 cm ^-1 and 15 when irradiated with 5 nm Ar ⁺ laser
When the spectral intensities at 7 cm ⁻¹ are a ₁ and b ₁ and the spectral intensities before the standing treatment are a ₀ and b ₀ , (b ₁
The greatest feature is that / a ₁ ) / (b ₀ / a ₀ )> 0.7 is satisfied, and it is necessary to satisfy the above formula by controlling the manufacturing conditions of the polarizing film.

For example, a polyvinyl alcohol-based resin having a high degree of polymerization may be selected as the raw fabric, or a vertical stretching may be added in the stretching process during the production of the polarizing film, or the stretching may be performed in two or more stages. Alternatively, a method of performing a drying treatment after laminating a protective layer such as a cellulose triacetate film can be realized alone or in combination, but the method is not limited thereto. The above-mentioned standing treatment method and Raman spectroscopic method will be described in more detail. First, the polarizing film obtained by the above-described method is used for a Raman spectrophotometer (for example, Jasco Corp., Jasco).
NR-1800M) as an excitation wavelength of 51
Irradiate with 4.5 nm Ar ⁺ laser (output 2 mW),
Measuring the spectral intensities a ₀ and b ₀ of 105 cm ^-1 and 157cm ^-1 at this time at room temperature (measurement time; 16 sec × 5
Time, measurement diameter; 200 μm, measurement mode; backscattering). Next, after attaching the cellulose triacetate film to both surfaces of the polarizing film as described above, after leaving it in the atmosphere of 80 ° C. and 90% RH for 200 hours, taking it out and peeling the cellulose triacetate film in cyclohexanone, Using the Raman spectrophotometer in the same manner as above, again the spectral intensities a ₁ of 105 cm ⁻¹ and 157 cm ⁻¹ of the polarizing film alone were measured.
And b ₁ are measured.

In determining the above-mentioned spectrum intensity, the respective spectrum intensities are read from the peaks of the chart obtained by the above-mentioned measurement method. The determination of the spectrum intensity is carried out by the waveform separation method using the least square method. Waveform separation is performed assuming that each peak is a Lorentz function including three variables (spectral position, spectral intensity, half width) and a baseline is a linear function including two variables (intercept, slope). It determines the spectral intensity. A polarizing film having a value of (b ₁ / a ₁ ) / (b ₀ / a ₀ ) consisting of a ₀ , b ₀ , a ₁ and b ₁ of more than 0.7 is used in the present invention. And preferably 0.7 to 1.5. When the value is 0.7 or less, the durability of the polarizing film is poor and the object of the present invention cannot be achieved. Further, in the present invention, when the value of (b ₀ / a ₀ ) is less than 1.1, that is, (b ₀ / a ₀ ) <1.1.
When the condition of is satisfied, it is particularly useful because it has excellent durability at high temperature and high humidity.

In the present invention, the protective layer is provided on both surfaces of the specific polarizing film as described above, and the functional layer is provided outside any one of the protective layers. As the protective layer, a film excellent in optical transparency and mechanical strength is used, for example, a cellulose acetate film, an acrylic film,
Examples thereof include polyester-based resin films, polyolefin-based resin films, polycarbonate-based films, polyether ether ketone-based films, and polysulfone-based films, with cellulose acetate-based films such as cellulose triacetate films being most preferred. In addition, regarding sticking of the polarizing film and the protective layer, natural or synthetic rubber, urethane resin, acrylic resin, butyral resin, epoxy resin, polyester resin, polyamide resin, polyvinyl alcohol resin, etc. are the main components. The adhesive or pressure-sensitive adhesive or the like can be used for the attachment by an air-drying method, a chemical curing method, a heat curing method, a heat melting method or the like.

Specific examples of the functional layer of the present invention include an antiglare layer, a hard coat layer, an antireflection layer, a half reflection layer, a reflection layer, a light storage layer, and an electroluminescence layer. It is also possible to combine, for example, a luminous layer and a reflection layer, a luminous layer and a half reflection layer, a luminous layer and a light diffusion layer, a luminous layer and an electroluminescence layer, a half reflection layer and an electroluminescence layer, an antiglare layer and an antireflection layer. And the like. However, it is not limited to these.

The anti-glare layer is for diffusing a reflection image of a fluorescent lamp or the like on the surface of the polarizing plate to make it easy to see the display, and for preventing the adhesion of fingerprints or the like. Melamine-based resins, urethane-based resins, acrylic-based resins, alkyd-based resins, silicone-based resins, etc. containing inorganic fillers such as silica beads of 1 to 20 μm and organic fillers such as acrylic, styrene, divinylbenzene, melamine and benzoguanamine Known thermosetting resin or polyfunctional acrylic energy ray curable resin such as ultraviolet ray or electron beam is used, and a known coating method such as bar coating, roll coating, gravure coating or air knife coating on the protective layer surface. Is applied by. The thickness of the antiglare layer is 1 to 20 μm.
It is a degree.

The hard coat layer has a surface hardness of H (pencil hardness) or more to impart scratch resistance, and specifically includes a melamine resin, a urethane resin, an acrylic resin,
A thermosetting resin such as an alkyd-based resin or a silicone-based resin or a polyfunctional acrylic resin as a main component, an energy ray-curable resin such as an ultraviolet ray or an electron beam, or a metal oxide such as SiO ₂ is used. Formed on the surface. As a method for forming the layer, known coating methods such as bar coating, roll coating, gravure coating, and air knife coating are preferably used in the case of a resin, and a vacuum evaporation method is preferably used in the case of a metal oxide. . The thickness of the hard coat layer is 1 to 20
It is about μ.

The anti-reflection layer is for suppressing the reflection of external light on the surface of the polarizing plate to make the display easier to see. Specifically, it is made of fluorine resin, SiO ₂ , MgF ₂ , Zr.
Metal oxides such as O ₂ , AlO ₃ and TiO ₂ are used,
It is formed on the surface of the protective layer. As a method for forming the layer, a known coating method such as bar coating, roll coating, gravure coating, and air knife coating is preferably used in the case of resin, and a vacuum deposition method is preferably used in the case of metal oxide, The metal oxide is often laminated in two or more layers, and the thickness of the antireflection layer is about 0.05 to 1 μm. or,
It is also effective to use a combination of the anti-reflection layer and the anti-glare layer.

The half-reflection layer is used to reflect external light in the daytime and to display a display by using transmitted light from the backlight at night to reduce power consumption. Is formed. Specifically, scaly mica, titanium dioxide-coated mica, plate-shaped fish scale foil, hexagonal plate-shaped basic lead carbonate, fine mica or pearl pigment such as bismuth acid chloride, fine glass beads, glass products such as ground glass particles, It has optical transparency of (meth) acrylic resin, acetate, polycarbonate, polyester, polyurethane, etc. by using an adhesive containing transparent and / or semi-transparent particles such as plastic chips, plastic crushed particles and other plastic products. The synthetic resin layer may be attached to a polarizing plate, or the film in which the transparent and / or semitransparent particles are coated on the synthetic resin layer may be attached to the polarizing plate via an adhesive. , But is not limited to this. The polarizing plate with a half-reflection layer is practically used as a lower polarizing plate of a liquid crystal panel, and a protective layer without a half-reflection layer is attached to the liquid crystal panel so that the half-reflection layer is a lower layer. You.

The reflective layer is used to display a display by utilizing external light reflection in the daytime and omit the backlight, and specifically, a cellulose acetate film such as a cellulose triacetate film, polyethylene terephthalate. A metal having a high reflectance such as aluminum or silver is vapor-deposited on a base material such as, and is bonded to a polarizing plate (one protective layer) via an adhesive. The polarizing plate with a reflective layer is practically used as a lower polarizer of a liquid crystal panel, and a protective layer having no reflective layer is bonded to the liquid crystal panel so that the reflective layer is a lower layer.

The luminous layer is for accumulating external light in the daytime so that a display can be displayed without a backlight at night. Specifically, zinc sulfide or calcium sulfide is used as a matrix, Copper is added as an activator to this, and a green phosphor that is mixed with a flux and fired is often used, or the phosphorescent coating contains an element that emits α-rays such as radium and strontium, and β-rays. It is used as a light-emitting paint that emits a small amount of light by itself. The light-storing layer is coated on one side (one protective layer) of the polarizing plate with a binder resin such as an acrylic resin, and the polarizing plate with the light-storing layer is practically used as a lower polarizing plate of a liquid crystal panel. That is, the protective layer having no light storage layer is bonded to the liquid crystal panel. It is also effective to provide a reflective layer below the luminous layer or to provide a half-reflection layer between the luminous layer and the polarizing plate.

The electroluminescent layer is intended to reduce the weight and thickness of the backlight instead of the conventional backlight, and is practically provided under the lower polarizing plate of the liquid crystal panel. As an electroluminescent material,
There are an inorganic material and an organic material, and the inorganic material includes phosphor particles such as zinc sulfide, and the organic material is tris (8-quinolinolato) aluminum complex.
Bis (benzoquinolinolato) beryllium complex and the like can be mentioned. In actual use, an ITO electrode is provided on one side (the polarizing plate side) of the electroluminescent layer, and a dielectric layer and a back electrode are provided on the other side, and current is passed through the ITO electrode and the back electrode to emit light. It is also effective to provide a light storage layer or a half reflection layer between the electroluminescence layer and the polarizing plate.

In the present invention, the above-mentioned various functional layers are provided on the polarizing plate, or various combinations of the various functional layers as described above are provided on the polarizing plate, whereby the optical performance is excellent and the conditions of high temperature and high humidity are high. It exerts an excellent effect on durability underneath.

Further, in the polarizing plate having the constitution of functional layer / protective layer / polarizing film / protective layer of the present invention, an acrylic pressure-sensitive adhesive layer is further provided on the protective layer side where the functional layer is not provided, and a liquid crystal display is provided. It is attached to a glass substrate such as a device and provided for mounting. As the acrylic pressure-sensitive adhesive, known ones are used, and as a component of the acrylic resin which is a main component of the acrylic pressure-sensitive adhesive, a soft main monomer component having a low glass transition temperature or a hard glass having a high glass transition temperature is used. A comonomer component and, if necessary, a small amount of a functional group-containing monomer component may be used.

Specifically, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-acrylic acid acrylate
Ethylhexyl, lauryl acrylate, benzyl acrylate, alkyl acrylates having about 2 to 12 carbon atoms of alkyl groups such as cyclohexyl acrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, Benzyl methacrylate, a main monomer component such as alkyl methacrylate having about 4 to 12 carbon atoms of an alkyl group such as cyclohexyl methacrylate, and the comonomer component include methyl acrylate, methyl methacrylate, ethyl methacrylate, Examples thereof include alkyl methacrylates having 1 to 3 carbon atoms such as propyl methacrylate, vinyl acetate, acrylonitrile, methacrylonitrile, and styrene.

In addition to the above, the functional group-containing monomer component is a monocarboxylic acid such as acrylic acid, methacrylic acid or crotonic acid, a polyvalent carboxylic acid such as maleic acid, fumaric acid, citraconic acid, glutaconic acid or itaconic acid, and Carboxyl group-containing monomers such as anhydrides, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxylpropyl (meth) acrylate, diethylene glycol mono (meth) acrylate, and the like. In addition to hydroxyl group-containing monomers such as N-methylolacrylamide, (meth) acrylamide, dimethylaminoethyl methacrylate, glycidyl methacrylate, allyl glycidyl ether and the like can be mentioned.

Among the functional group-containing monomer components,
Particularly, use of a carboxyl group-containing monomer is preferred. Although the content of such a main monomer component cannot be unconditionally defined by the type or content of a comonomer component or a functional group-containing monomer component to be contained, it is generally preferable to contain the main monomer in an amount of 50% by weight or more. . The acrylic resin of the present invention is easily produced by a method well known to those skilled in the art, such as radical copolymerization of a main monomer, a comonomer, and, if necessary, a functional group-containing monomer in an organic solvent.

The organic solvent used for the above polymerization is
Aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as n-propyl alcohol and isopropyl alcohol; ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone. . Specific examples of the polymerization catalyst used in the radical polymerization include azobisisobutyronitrile, benzoyl peroxide, di-t-butyl peroxide, cumene hydroperoxide and the like, which are ordinary radical polymerization catalysts.

If necessary, the acrylic resin may contain additives such as a crosslinking agent and a coupling agent (silicone, aluminum, titanium) in an amount of 0.001 to 5% by weight, and finally the pressure-sensitive adhesive of the present invention. Becomes Examples of the crosslinking agent include isocyanate compounds, epoxy compounds, aldehyde compounds, amine compounds, metal salts, metal alkoxides, metal chelate compounds, ammonium salts, and hydrazine compounds. The amount of the cross-linking agent to be blended is about 0.001 to 8 parts by weight with respect to 100 parts by weight of the acrylic resin.

Thus, the polarizing plate of the present invention has a temperature of 80.degree.
Raman spectroscopic measurement values before and after standing for 200 hours in an atmosphere of% RH use a polarizing film that shows a specific relationship, and since various functional layers are further provided, it has excellent polarization characteristics and is excellent in high temperature and high humidity conditions. It has excellent durability and fully exhibits the functions of various functional layers. It is used for electronic desk calculators, electronic watches, word processors, liquid crystal display devices for measuring instruments such as automobiles and machinery, sunglasses, eye protection glasses, stereo glasses, and displays. Element (CRT, L
It is used as a reflection reducing layer for CDs, etc., and is particularly useful for liquid crystal display devices such as measuring instruments for automobiles and machinery.

[0033]

EXAMPLES The polarizing plate of the present invention will be described in more detail with reference to examples. In the examples, “parts” and “%” are based on weight unless otherwise specified. The degree of polarization in the present invention is represented by the following equation. [(H ₁₁ −H ₁ ) / (H ₁₁ + H ₁ )] ^1/2 × 100 (%) where H ₁₁ is the same when the two polarizing film samples are superposed on each other. The transmittance (%) and H ₁ measured with a spectrophotometer in the state of being overlapped so that when the two samples are superposed, they are superposed so that the orientation directions of the polarizing films are orthogonal to each other. It is the transmittance (%) measured in the combined state.

Examples 1- (1) to (7) Polyvinyl alcohol having an average degree of polymerization of 1700 and an average degree of saponification of 99.5 mol% was dissolved in water to obtain an aqueous solution having a concentration of 5.0% by weight. The solution was cast on a polyethylene terephthalate film and dried to obtain a film having a thickness of 60 μm. This film was cut into a width of 10 cm and mounted on a chuck. The film was washed with iodine 0.2 g / l, potassium iodide 6
It was immersed in an aqueous solution of 0 g / l at 30 ° C. for 4 minutes. Then, it was immersed in an aqueous solution having a composition of boric acid 70 g / l and potassium iodide 30 g / l for 5 minutes at 55 ° C., and first stretched 2.2 times and then 1.7 times, and further 1. The film was stretched 5 times, washed with water at 20 ° C. for 10 seconds, and air-dried for 24 hours to obtain a stretched film. And
Cellulose triacetate film (Fujitac F, manufactured by Fuji Photo Film Co., Ltd.) whose surface has been alkali treated and neutralized with acid in advance
T-UV 80, 80 μm thick) was applied on both sides of the stretched film using a polyvinyl alcohol adhesive (3% aqueous solution, dry coating thickness 0.01 μm) and dried at 100 ° C. for 1 minute to obtain a polarizing plate.

Next, the polarizing plate was placed in cyclohexanone 20
The cellulose triacetate film was completely removed by immersing it at 12 ° C. for 12 hours to obtain a polarizing film. The polarizing film (20 mm × 20 mm) was irradiated with an Ar ⁺ laser having an excitation wavelength of 514.5 nm using a Raman spectrometer (Jasco NR-1800M manufactured by JASCO Corporation) under the conditions described in the text. 105 cm ^-1 and 157 cm ^-1
Was measured at room temperature to find that it was 37.81.
(A ₀ ) and 29.88 (b ₀ ). Further, the above-mentioned cellulose triacetate film was again adhered to both sides of the polarizing film as a protective layer with a polyvinyl alcohol adhesive in the same manner as in the above-mentioned method to form a three-layer laminate of cellulose triacetate / polarizing film / cellulose triacetate (polarizing plate). ) Got. Next, the three-layer laminate is subjected to 200 ° C. in an atmosphere of 80 ° C. and 90% RH.
After leaving for 3 hours to obtain a three-layer laminate after the treatment, the laminate is immersed in cyclohexanone for 12 hours at 20 ° C. to remove the protective layer to obtain a polarizing film alone, similarly using a Raman spectrometer. Again 105 cm of the polarizing film
^-1 and 157 cm ^-1 were measured to obtain spectral intensities of 30.94 (a ₁ ) and 28.38 (b ₁ ). From these measured values, (b ₀ / a ₀ ) and (b ₁ / a ₁₎ ) / (B ₀
The value of / a ₀ ) was calculated to be 0.79 and 1.16.

A polarizing plate of the present invention was obtained by providing a functional layer as shown in Table 1 on one surface of the above polarizing plate. In order to examine the durability of the polarizing plate, the above polarizing plate was placed at 65 ° C. and 95%.
After standing for 500 hours under RH conditions, measure the single-body transmittance and polarization degree after that with a spectrophotometer, and measure the single-body transmittance change and polarization degree change from the single-body transmittance and polarization degree before the standing treatment. did.

The functional evaluation of the polarizing plate with various functional layers was evaluated by the following methods. (Anti-glare layer) Diffusivity of fluorescent lamp The display quality of the image when the fluorescent lamp was transferred to the polarizing plate was evaluated according to the following criteria. A: The shape of the fluorescent lamp could not be recognized B: The shape of the fluorescent lamp could be recognized Change in haze value The haze value before and after the polarizing plate was left under the above conditions was measured and evaluated according to the following criteria.・ ・ ・: Change rate of haze value before and after leaving less than 30% ×: Change rate of haze value before and after leaving is 30% or more

(Hard coat layer) Scratch resistance Steel wool is applied to the surface of the polarizing plate at 1 kg / cm ² .
The presence or absence of scratches when rubbed 0 times was measured and evaluated according to the following criteria. ○ ・ ・ ・ No scratch × ・ ・ ・ Scratch Surface pencil hardness The surface hardness of the polarizing plate was measured according to JIS K 5400 and evaluated according to the following criteria. ○ ・ ・ ・ having surface hardness of H or more × ・ ・ ・ having surface hardness of less than H

(Anti-Reflection Layer) Reflection of Fluorescent Lamp The display quality of the image when a fluorescent lamp was projected on the polarizing plate was evaluated according to the following criteria. A: Other display is not hindered by the reflection of the fluorescent lamp B: Other display is hindered by the reflection of the fluorescent lamp Surface reflectance Reflectivity before and after the polarizing plate is left under the above conditions Measure
Evaluation was made according to the following criteria. ○ ・ ・ ・ Change rate of reflectance before and after leaving is less than 30% × ・ ・ ・ Change rate of reflectance before and after leaving is 30% or more

(Half Reflection Layer) Actual Display Quality at Night and Day The display of the polarizing plate was evaluated at night and day according to the following criteria. A: Notation can be recognized in a short time at night and daytime B: Notation cannot be recognized in a short time at night and daylight Transmittance The transmittance of the polarizing plate before and after being left under the above conditions is measured,
Evaluation was made according to the following criteria.・ ・ ・: Change in transmittance before and after standing is less than 30% ×: Change in transmittance before and after standing is 30% or more Reflectivity Measure reflectance before and after leaving the polarizing plate under the above conditions And
Evaluation was made according to the following criteria. ○ ・ ・ ・ Change rate of reflectance before and after leaving is less than 30% × ・ ・ ・ Change rate of reflectance before and after leaving is 30% or more

(Reflective layer) Actual display quality during the daytime The display of the polarizing plate during the daytime was evaluated according to the following criteria. A: The notation can be recognized in a short time B: The notation cannot be recognized in a short time Reflectance The reflectance before and after the polarizing plate is left under the above conditions is measured.
Evaluation was made according to the following criteria. ○ ・ ・ ・ Change rate of reflectance before and after leaving is less than 30% × ・ ・ ・ Change rate of reflectance before and after leaving is 30% or more

(Luminescent layer) Actual display quality at night The display of the polarizing plate at night was evaluated according to the following criteria. A: The notation is recognizable. B: The notation is not recognizable. Surface luminance The luminance before and after the polarizing plate was left under the above conditions was measured and evaluated according to the following criteria.・ ・ ・: Change rate of luminance before and after leaving less than 30% ×: Change rate of luminance before and after leaving is 30% or more

(Electroluminescence Layer) Actual Display Quality at Night The display of the polarizing plate at night was evaluated according to the following criteria. A: Notation can be recognized in a short time B: Notation can not be recognized in a short time Surface luminance The luminance before and after the polarizing plate is left under the above conditions is measured, and based on the following criteria. evaluated.・ ・ ・: Change rate of luminance before and after leaving less than 30% ×: Change rate of luminance before and after leaving is 30% or more

[0044]

[Table 1] Functional layer Composition of functional layer Film thickness (μ) Example 1 (1) AG layer Coated with 1% of silica filler having a particle size of 3 μm mixed in acrylic resin (2) HC layer acrylic resin Coat 1 (3) AR layer Coated with fluorine resin 0.1 (4) HR layer Coated with 10% 10% titanium dioxide-coated mica in acrylic resin (5) GR layer PET film was vapor-deposited with silver 1 layer of film (6) Luminescent layer Coated with acryl resin containing 5% of zinc sulfide and 5% of copper 5 phosphorescent material coated (7) EL layer Bis (benzoquinolinolite 5) in acrylic resin coated on PE T film obtained by blending a beryllium 5%, further laminated one which formed transparency electrode of ITO Note) AG layer: anti-glare layer, HC layer: hard coat layer, AR layer: Anti-reflection layer, HR layer: half-reflection layer, GR layer: reflection layer, EL layer: electroluminescence layer, PET: polyethylene terephthalate

Example 2- (1) to (7) In Example 1, polyvinyl alcohol having an average polymerization degree of 2600 and an average saponification degree of 99.5 mol% was used, and the initial draw ratio was doubled in the drawing step. Aside from the change, the same operation as in Example 1 was performed, and a
_{When 0} , b ₀ , a ₁ and b ₁ were measured, a ₀ = 42.2
3, b ₀ = 36.32, a ₁ = 27.42, b ₁ = 22.
At 53, from these measured values, (b ₀ / a ₀ ) and (b ₁ /
The values of a ₁ ) / (b ₀ / a ₀ ) were calculated to be 0.86 and 0.95. On one surface of the obtained polarizing plate, Example 1 was applied.
The polarizing plate of the present invention was obtained by providing the functional layer as shown in Table 1 used in. The durability and functionality of the polarizing plate were evaluated in the same manner as in Example 1.

Example 3- (1) to (7) In Example 1, polyvinyl alcohol having an average degree of polymerization of 4000 and an average degree of saponification of 99.5 mol% was used, and stretched three times in the stretching step, and then, Example 1 except that the stretching treatment was only performed in two steps of stretching 1.7 times and the drying temperature after the cellulose triacetate film lamination was changed to 60 ° C.
Perform the same operation as above, and use a Raman spectrometer to measure a ₀ ,
When b ₀ , a ₁ and b ₁ were measured, a ₀ = 35.27,
b ₀ = 31.69, a ₁ = 39.63, b ₁ = 27.05
From these measured values, (b ₀ / a ₀ ) and (b ₁ / a ₁ ) /
The value of (b ₀ / a ₀ ) was calculated to be 0.90 and 0.76. The polarizing plate of the present invention was obtained by providing the functional layer as shown in Table 1 used in Example 1 on one surface of the obtained polarizing plate. The durability and functionality of the polarizing plate were evaluated in the same manner as in Example 1.

Comparative Example 1 In Example 1, the stretching treatment was carried out only once, 5.6 times, and the drying temperature after lamination of the cellulose triacetate film was 60.
The same operation as in Example 1 was performed except that the temperature was changed to 0 ° C., and a ₀ , b ₀ , a ₁ and b ₁ were measured by the Raman spectrophotometer, and a ₀ = 12.15, b ₀ = 22. 92, a ₁ = 1
4.72, b ₁ = 18.73, and from these measured values (b ₀
The values of / a ₀ ) and (b ₁ / a ₁ ) / (b ₀ / a ₀ ) were calculated to be 1.89 and 0.67. The durability of the obtained polarizing plate was evaluated in the same manner as in Example 1.

Comparative Example 2 In Example 1, polyvinyl alcohol having an average degree of polymerization of 2600 and an average degree of saponification of 99.5 mol% was used, and the stretching treatment was performed only 5.1 times, and after the cellulose triacetate film was laminated. except for changing the drying temperature to 60 ° C., the same procedure as in example 1, a ₀ by Raman spectrometer,
When b ₀ , a ₁ and b ₁ were measured, a ₀ = 28.00,
b ₀ = 38.09, a ₁ = 21.06, b ₁ = 28.64.
From these measured values, (b ₀ / a ₀ ) and (b ₁ / a ₁ ) /
The calculated values of (b ₀ / a ₀ ) were 1.36 and 0.62. The durability of the obtained polarizing plate was evaluated in the same manner as in Example 1.

Comparative Example 3 In Example 1, polyvinyl alcohol having an average degree of polymerization of 4000 and an average degree of saponification of 99.5 mol% was used, and the stretching treatment was performed 5.1 times only once, and after the cellulose triacetate film was laminated. except for changing the drying temperature to 60 ° C., the same procedure as in example 1, a ₀ by Raman spectrometer,
When b ₀ , a ₁ and b ₁ were measured, a ₀ = 34.56,
b ₀ = 41.70, a ₁ = 36.41, b ₁ = 25.46
From these measured values, (b ₀ / a ₀ ) and (b ₁ / a ₁ ) /
The value of (b ₀ / a ₀ ) was 1.21 and 0.58. The durability of the obtained polarizing plate was evaluated in the same manner as in Example 1. Table 2 shows the evaluation results of the examples and comparative examples.

[0050]

[Table 2]Before durability test After durability test Evaluation of functional layers Degree of polarization Degree of polarization Change of degree of polarization(%) (%) (%) Example 1 (1) 99.9 98.8 -1.1 A o-(2) 99.9 98.8 -1.1 o o-(3) 99.9 98.8 -1.1 A o -(4) 99.9 98.8-1.1 A ○○ (5) 99.9 98.8-1.1A ○-(6) 99.9 98.8-1.1A ○-( 7) 99.9 98.8-1.1 A ○ -Example 2 (1) 99.9 99.1-0.8 A ○-(2) 99.9 99.1-0.8 ○○- (3) 99.9 99.1 −0.8 A ○ − (4) 99.9 99.1 −0.8 A ○ ○ (5) 99.9 99.1 −0.8 A ○ − (6 ) 99.9 99.1 −0.8 A ○ − (7) 99.9 99.1 −0.8 A ○ − Example 3 (1) 99.9 99.3 −0.6 A ○ − ( 2) 99.9 99.3-0. ○ ○ − (3) 99.9 99.3 −0.6 A ○ − (4) 99.9 99.3 −0.6 A ○ ○ (5) 99.9 99.3 −0.6 A ○ -(6) 99.9 99.3-0.6 A ○-(7) 99.9 99.3 −0.6 A ○ −  Comparative Example 1 99.8 77.1 −22.7 − − − 〃 2 99.9 81.3 −18.6 − − −〃 3 99.8 85.6 -14.2--- Note) In the table, evaluations of functional layers are based on each of the above evaluation methods.

[0051]

The polarizing plate of the present invention is 80 ° C. and 90% RH.
Raman spectroscopic measurement values before and after standing in the atmosphere for 200 hours use a polarizing film that shows a specific relationship, and since various functional layers are provided, it has excellent polarization characteristics and high temperature.
It has excellent durability in high humidity conditions, fully demonstrates the functions of various functional layers, liquid crystal display devices such as electronic desktop calculators, electronic watches, word processors, instruments for automobiles and machinery, sunglasses, eyeglasses, Stereo glasses, display elements (CRT, LCD, etc.)
And is particularly useful for liquid crystal display devices such as instruments for automobiles and machinery.

Claims (15)

[Claims] 1. A polarizing plate having a structure of functional layer / protective layer / polarizing film / protective layer, wherein the polarizing film comprises 8
0 ° C., and the spectral intensity of 105 cm ^-1 and 157cm ^-1 at Ar ⁺ laser irradiation of the excitation wavelength 514.5nm by 200 hours standing after treatment of Raman spectroscopy in an atmosphere of RH 90% as a ₁ and b ₁ respectively A polyvinyl alcohol-based polarizing film satisfying (b ₁ / a ₁ ) / (b ₀ / a ₀ )> 0.7, where the spectral intensities before the standing treatment of the polarizing film are a ₀ and b ₀ , respectively. A polarizing plate characterized by being used. 2. The polarizing plate according to claim 1, wherein a polyvinyl alcohol-based polarizing film satisfying (b ₀ / a ₀ ) <1.1 is used. 3. The polarizing plate according to claim 1, wherein the functional layer is an antiglare layer. 4. The polarizing plate according to claim 1, wherein the functional layer is a hard coat layer. 5. The polarizing plate according to claim 1, wherein the functional layer is an antireflection layer. 6. The polarizing plate according to claim 1, wherein the functional layer is a half reflection layer. 7. The polarizing plate according to claim 1, wherein the functional layer is a reflective layer. 8. The polarizing plate according to claim 1, wherein the functional layer is a light storage layer. 9. The polarizing plate according to claim 1, wherein the functional layer is an electroluminescence layer. 10. The functional layer comprises an anti-glare layer and an anti-reflection layer.
The polarizing plate described. 11. The polarizing plate according to claim 1, wherein the functional layer comprises a light storing layer and a reflecting layer. 12. The polarizing plate according to claim 1, wherein the functional layer comprises a light storage layer and a half reflection layer. 13. The polarizing plate according to claim 1, wherein the functional layer comprises a light storage layer and a light diffusion layer. 14. The polarizing plate according to claim 1, wherein the functional layer comprises a light storage layer and an electroluminescence layer. 15. The polarizing plate according to claim 1, wherein the functional layer comprises a half reflection layer and an electroluminescence layer.