JP2009237460A - Manufacturing method of polarizing film, manufacturing method of polarizing plate and projection type image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a polarizing film, capable of manufacturing the polarizing film for which the temperature of a polarizer is not elevated, even when the one which emits strong light is used as a light source. <P>SOLUTION: In the manufacturing method of the polarizing film, a pigment-containing resin solution is applied to at least one surface of the polarizer obtained by stretching a resin film, immersing it in a pigment solution and immersing it in a boric acid solution. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polarizing film manufacturing method, a polarizing plate manufacturing method, and a projection type image display device.

Projection-type display devices are rapidly spreading as large screen display devices. A projection display device guides light from a light source to a transmissive liquid crystal display element, which creates an image by light intensity modulation, and enlarges the created image with a projection lens, thereby displaying a large screen display. It is a device to realize. In such a projection type display device, an absorptive polarizing plate in which a dichroic dye is adsorbed on a stretched polyvinyl alcohol (PVA) film is used.
In recent years, projection display devices have been increased in luminance, and accordingly, a light source that emits powerful light has been used. The dichroic dye contained in the absorption-type polarizing plate is rapidly deteriorated by being exposed to intense light from a light source, and further, the decomposition of the dye molecules caused by the photochemical reaction is accelerated by heat. Further, when the PVA film is heated to the glass transition temperature or higher, the decomposition reaction of the pigment is accelerated.
Thus, Patent Document 1 discloses a technique for preventing the polarizing plate from being heated at a high temperature by dispersing heat absorbed by the polarizing plate by combining a plurality of polarizing plates having different degrees of polarization.
Japanese Patent Laid-Open No. 10-133196

  However, in the method shown in Patent Document 1, when a light source that emits strong light is used as the light source, the protective film of each of the plurality of polarizing plates functions as a heat insulating layer. Heat dissipation was hindered and the temperature increased, and the decomposition reaction of the dye could be accelerated.

  The present invention is a method for producing a polarizing film, in which a resin film is stretched, dipped in a dye solution, and a dye-containing resin solution is applied to at least one surface of a polarizer that can be obtained by dipping in a boric acid solution.

  Moreover, this invention is a manufacturing method of the polarizing plate which bonds a protective film or a board | substrate to the at least single side | surface of the polarizing film manufactured by the manufacturing method of the said polarizing film.

The present invention also includes a light source,
A polarizing plate manufactured by the manufacturing method of the polarizing plate;
Separating means for separating light that has passed through the polarizing plate,
The projection-type image display device is provided with a polarizing plate so that light is incident from the side coated with the dye-containing resin solution and emitted from the polarizer side.

  According to the method for producing a polarizing film of the present invention, a polarizing film having excellent durability can be produced even when a light source that emits strong light is used.

FIG. 1 is a schematic view for explaining a method for producing the polarizing film 1 and the polarizing plate 6 of the present invention.
In the method for producing the polarizing film 1 of the present invention, the resin film 2 is stretched (hereinafter sometimes referred to as “stretching step”), immersed in a dye solution (hereinafter sometimes referred to as “dyeing step”), and then immersed in a boric acid solution. Immersion (hereinafter may be referred to as “crosslinking step”) to produce a polarizer 3, and a dye-containing resin solution is applied to at least one surface of the polarizer 3 (hereinafter also referred to as “application step”) to obtain polarized light. The membrane 1 is manufactured.
In the manufacturing method of the polarizing plate 6 of this invention, the protective film 5 is bonded on the polarizing film 1 (it may be hereafter called a "protective film bonding process"), and the polarizing plate 6 is manufactured.

[Stretching process]
In the stretching step, the resin film 2 is usually stretched about 3 to 8 times. As the stretching method, uniaxial stretching is preferred. In the stretching process, the stretching device 12 is used. In uniaxial stretching, it may be uniaxially stretched between rolls having different peripheral speeds, or may be uniaxially stretched using a hot roll. Moreover, the dry-type extending | stretching which extends | stretches in air | atmosphere may be sufficient, and the wet extending | stretching which extends | stretches in the state swollen in the solvent may be sufficient.
Uniaxial stretching may be performed before the dyeing process described later, may be performed simultaneously with the dyeing process, or may be performed after the dyeing process, as shown in the present embodiment. When uniaxial stretching is performed after the dyeing step, this uniaxial stretching may be performed before the crosslinking step (boric acid treatment) or during the crosslinking step. Of course, it is also possible to perform uniaxial stretching in these plural stages.

The resin film 2 is made of a base material such as a polyvinyl alcohol (hereinafter sometimes referred to as “PVA”) resin, a polyvinyl acetate resin, an ethylene / vinyl acetate (hereinafter sometimes referred to as “EVA”) resin, a polyamide resin, or a polyester resin. Consists of.
For PVA-based resins, polyvinyl alcohol, which is a partially saponified product of polyvinyl acetate;
Vinyl acetate and other copolymerizable monomers such as saponified EVA resin (for example, olefins such as ethylene and propylene, unsaturated carboxylic acids such as crotonic acid, acrylic acid, methacrylic acid and maleic acid, Saponified products of copolymers with saturated sulfonic acids, vinyl ethers, etc.);
Examples include polyvinyl formal obtained by modifying polyvinyl alcohol with aldehyde, polyvinyl acetal, and the like.
As the resin film 2, a PVA-based resin film, particularly a PVA film itself, is preferably used from the viewpoint of dye adsorption and orientation.
The degree of saponification of the PVA resin is usually about 85 to 100 mol%, preferably 98 mol% or more. Moreover, the polymerization degree of PVA-type resin is about 1,000-10,000 normally, Preferably it is about 1,500-5,000.
What formed this base material into a film is the resin film 2 used as a raw film of the polarizing film 1. The method for forming the substrate is not particularly limited, and can be formed by a known method. Although the film thickness of the resin film 2 is not specifically limited, For example, it is about 10 micrometers-150 micrometers.

[Dyeing process]
In the dyeing process, the resin film 2 is immersed in the dye solution. That is, a dye is adsorbed on the resin film 2 and dyed. In the dyeing process and the crosslinking process described below, the dyeing device 13 is used. In addition, it is preferable that the resin film 2 is immersed in water before the dyeing process.

As the dye, a dichroic dye is used, and specifically, iodine or a dichroic dye is used as the dichroic dye.
As the dichroic dye, a dichroic dye is preferable because it is easily adsorbed and oriented on the resin film 2 and is excellent in light resistance. By using dyes having different wavelength dependencies, it is possible to produce respective polarizers for the blue channel, the green channel, and the red channel of the projection type liquid crystal display device.

When iodine is used as the dichroic dye, a method of dyeing the resin film 2 by dipping it in an aqueous solution containing iodine and potassium iodide is usually employed. The content of iodine in this aqueous solution is usually about 0.01 to 1 part by weight per 100 parts by weight of water, and the content of potassium iodide is usually about 0.5 to 20 parts by weight per 100 parts by weight of water. It is. The temperature of the aqueous solution used for dyeing is usually about 20 to 40 ° C., and the immersion time (dyeing time) in this aqueous solution is usually about 20 to 1,800 seconds.
On the other hand, when a dichroic dye is used as the dichroic dye, a method of immersing and dyeing the resin film 2 in an aqueous solution containing a water-soluble dichroic dye is usually employed. The content of the dichroic dye in this aqueous solution is usually about 1 × 10 ⁻⁴ to 10 parts by weight, preferably about 1 × 10 ⁻³ to 1 part by weight per 100 parts by weight of water. It may be about 10 ⁻² parts by weight or less. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing assistant. The temperature of the aqueous dye solution used for dyeing is usually about 20 to 80 ° C., and the immersion time (dyeing time) in this aqueous solution is usually about 10 to 1,800 seconds.

  Examples of the dichroic dye include compounds described in “Development of dichroic dyes for liquid crystal display devices” (Sone et al., Sumitomo Chemical, 2002-II, pp. 23-30).

Specifically, a dichroic dye represented by the formula (I) in the form of a free acid,

(In the formula, Me represents a metal atom selected from a copper atom, a nickel atom, a zinc atom and an iron atom. A ¹ represents an optionally substituted phenyl group or an optionally substituted naphthyl group. B ¹ Represents an optionally substituted naphthylene group, and an oxygen atom bonded to Me and an azo group represented by -N = N- are formed by bonding carbons on the benzene ring to carbons adjacent to each other. R ¹ and R ² are each independently an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, a carboxyl group, a sulfoxy group, a sulfonamide group, a sulfonalkylamide group, an amino group, an acylamino group, Represents a halogen atom or a nitro group.)

A dichroic dye of the formula (II) in the form of a free acid,

(In the formula, A ³ and B ³ each independently represent a phenyl group which may be substituted or a naphthyl group which may be substituted; R ³ and R ⁴ each independently represent a hydrogen atom, a carbon number of 1 to 4; An alkyl group, a C 1-4 alkoxyl group, a carboxyl group, a sulfoxy group, a sulfonamide group, a sulfonealkylamide group, an amino group, a halogen atom or a nitro group, and m represents an integer of 0 or 1.)

A dichroic dye of the formula (III) in the form of the free acid,
^{Q 1 -N = N-Q 2} -X-Q 3 -N = N-Q 4 (III)
[Wherein, Q ¹ and Q ⁴ each independently represent an optionally substituted phenyl group or an optionally substituted naphthyl group, and X represents a chemical formula (III-1) or a chemical formula (III-2). The bivalent residue is shown. Q ² and Q ³ each independently represent an optionally substituted phenylene group. ]

A dichroic dye represented by the formula (IV),

[Wherein, Me represents a metal atom selected from a copper atom, a nickel atom, a zinc atom and an iron atom, Q ⁵ and Q ⁶ each independently represents a naphthylene group which may have a substituent, and Me and In the bonded oxygen atom and the azo group represented by -N = N-, the carbons on the benzene ring are bonded to carbons adjacent to each other. Y represents a divalent residue represented by chemical formula (IV-1) or chemical formula (IV-2). R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, or a sulfoxy group. ]

Furthermore, C eye direct yellow-12, c eye direct red 31, c eye direct red 28, c eye direct yellow 44, c eye direct 44・ Yellow-28, SH-I Direct Orange 107, SH-I Direct Red 79, SH-I Direct Red 2, SH-I Direct Red 81, SH-I. Color Index Generic Name (Color) shown in the group consisting of Direct Orange 26, C Eye Direct Orange 39, C Eye Direct Red 247, and C Eye Direct Yellow 142 A dichroic dye represented by Index Generic Name) is exemplified.

The dichroic dye may be used in the form of a free acid, or may be used in the form of an amine salt such as an ammonium salt, an ethanolamine salt, or an alkylamine salt. Usually, a lithium salt, a sodium salt, Used in the form of alkali metal salts such as potassium salts.
Such dichroic dyes may be used alone or in combination of two or more.

[Crosslinking process]
In the cross-linking step, the resin film 2 obtained in the dyeing step is cross-linked. That is, after the dyeing, the resin film 2 is treated with boric acid. The boric acid treatment is performed by immersing the resin film 2 in a boric acid-containing aqueous solution and washing with water after the treatment with the boric acid aqueous solution. The amount of boric acid in the boric acid-containing aqueous solution is usually about 2 to 15 parts by weight, preferably about 5 to 12 parts by weight per 100 parts by weight of water. When iodine is used as the pigment, this boric acid-containing aqueous solution preferably contains potassium iodide. The amount of potassium iodide in the boric acid-containing aqueous solution is usually about 0.1 to 15 parts by weight, preferably about 5 to 12 parts by weight per 100 parts by weight of water. The immersion time in the boric acid-containing aqueous solution is usually about 60 to 1,200 seconds, preferably about 150 to 600 seconds, and more preferably about 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 50 ° C. or higher, preferably 50 to 85 ° C., more preferably 60 to 80 ° C.

  The resin film 2 after the boric acid treatment is usually washed with water. The water washing treatment is performed by, for example, immersing the boric acid-treated resin film 2 in water. The temperature of water in the water washing treatment is usually about 5 to 40 ° C., and the immersion time is usually about 1 to 120 seconds. After washing with water, a drying process is performed. The drying process is usually performed using a hot air dryer or a far infrared heater. The temperature of the drying treatment is about 30 to 100 ° C, preferably 60 to 95 ° C. The time for the drying treatment is usually about 60 to 600 seconds, preferably 120 to 600 seconds.

  The polarizer 3 thus obtained preferably has an absorption polarization transmittance of 0.1% or less. In order to reduce the absorption polarization transmittance of the polarizer 3 to 0.1% or less, a dye may be appropriately selected.

[Coating process]
In the coating step, the dye-containing resin solution is applied to at least one surface of the polarizer 3. A dye-containing resin solution is applied onto the polarizer 3 by a coating method to form the dye layer 4. According to the method of forming the dye layer 4 on the polarizer 3 by the coating method, the dye layer 4 can be easily formed on the polarizer 3 as compared with the roll-to-roll process in which the films are bonded to each other. Since the stretched PVA film constituting the polarizer 3 is very easy to break, and the dye layer 4 is also very thin, it is not suitable to use roll-to-roll processing for bonding them. As the coating method, a coating method using a die coater, a chip coater, a gravure coater or the like can be used. Thereby, the polarizing film 1 including the polarizer 3 and the dye layer 4 is formed. The solution containing the pigment is applied by the coating device 14.
Examples of the dye include S.I.Direct Yellow-12, S.I.Direct Red 31, S.I.Direct Red 28, C.I.Direct Yellow 44, and C.I.・ Direct yellow 28, See eye direct orange 107, See eye direct red 79, See eye direct red 2, See eye direct red 81, See Color index generic name shown in the group consisting of Eye Direct Orange 26, Sea Eye Direct Orange 39, Sea Eye Direct Red 247 and Sea Eye Direct Yellow 142 Examples include dichroic dyes represented by (Color Index Generic Name).
An appropriate dye is selected according to the wavelength band in which the polarizing plate is used. As a solvent of the solution containing the pigment, water, ethanol, isopropyl alcohol, or the like can be used, and water can be used particularly preferably. As the solution, for example, a solution in which a dichroic dye is dispersed or dissolved in a PVA resin solution can be used. The PVA resin solution is preferably a solution containing PVA having a molecular weight of 20000 to 200,000.

  In the coating step, the dye layer is preferably formed so that the absorption polarization transmittance of the dye layer 4 is greater than 0.1%. What is necessary is just to select a pigment | dye suitably so that the absorption polarization transmittance | permeability of the pigment | dye layer 4 may become larger than 0.1%. From the viewpoint of improving light resistance, the absorption polarization transmittance of the dye layer 4 is preferably 30% to 60%. More preferably, it is 40% to 50%. When the light resistance of the dye layer 4 and the polarizer 3 is approximately the same, the transmittance is preferably set so that the light energy absorption amount of the dye layer 4 and the polarizer 3 is close to 1: 1.

FIG. 2 is a schematic view showing the polarizing film 1 of the present invention. The polarizing film 1 includes a polarizer 3 and a dye layer 4.
Since the polarizing film 1 of the present invention is formed by directly laminating the dye layer 4 on the polarizer 3 without providing a protective film, the heat dissipation efficiency is good.

[Protective film bonding process]
In the protective film bonding step, the protective film 5 is bonded onto the dye layer 4 of the polarizing film 1 by the roll-to-roll method, and the polarizing plate 6 is obtained. The protective film 5 is supplied from the roll 15. The protective film 5 is a triacetyl cellulose-based film (for example, Fujitac TD80, Fujitac TD80UF, Fujitac TD80UZ and Fujitac T40UZ (all trade names, manufactured by Fuji Film Co., Ltd.), KC8UX2M, KC8UY, KC4UY (all trade names, Konica Minolta Opto Co., Ltd.)), cyclic cycloolefin film (for example, ZEONOR film (trade name, manufactured by ZEON CORPORATION), Arton Film (trade name, manufactured by JSR Corporation)), polyethylene terephthalate film, nylon A film, a polycarbonate film, a polyethylene film, or the like can be used. Particularly preferably, a triacetyl cellulose film or a cyclic cycloolefin film having a small optical anisotropy can be used. The thickness of the protective film 5 is preferably 20 μm to 200 μm.
The protective film 5 is bonded onto the dye layer 4 of the polarizing film 1 using an adhesive / adhesive, but here, in addition to an agent that cannot be peeled (an agent that causes peeling with material destruction), You may paste the protective film 5 using the agent which can peel without accompanying material destruction, such as adhesive polyethylene resin and a light peeling acrylic adhesive. As a result, the protective film 5 can be peeled off later and directly attached to a material with high heat dissipation.
Furthermore, it is good also as polarizing plate 6 'by which 2nd protective film 5' is bonded on the polarizer 3 of the polarizing film 1, and both surfaces of the polarizing film 1 are protected by the protective film 5 and 2nd protective film 5 '. . Or it is good also as a polarizing plate with which only 2nd protective film 5 'was bonded.

FIG. 3 is a schematic view showing the polarizing plate 6 of the present invention. The polarizing plate 6 includes a polarizer 3, a dye layer 4, and a protective film 5.
The polarizer 3 is formed in contact with the dye layer 4. The polarizing film 1 made of these is protected by the protective film 5 on the dye layer 4 side.
The polarizing plate 6 produced in this way can suppress the generation of defects when rolled up in a roll shape by laminating the protective film 5 on the dye layer 4 of the polarizing film 1 to facilitate handling. it can. The protective film 5 is bonded using a pressure-sensitive adhesive / adhesive, but here, in addition to a non-peelable agent (an agent that causes delamination with material destruction), self-adhesive polyethylene resin or light-peeling acrylic You may paste the protective film 5 using the agent which can peel, such as an adhesive. As a result, the protective film 5 can be peeled off later and directly attached to a material with high heat dissipation.

  Since the polarizing plate 6 of the present invention is formed by directly laminating the dye layer 4 on the polarizer 3 without providing a protective film, the heat dissipation efficiency is good. In addition, when light enters from the dye layer 4 side, the dye layer 4 is directly exposed to light, and the dye included in the polarizer 3 is not directly exposed to light. 3 can be suppressed.

FIG. 4 is a schematic view showing the polarizing plate 6 ′ of the present invention. The polarizing plate 6 ′ includes a polarizer 3, a dye layer 4, a protective film 5, and a second protective film 5 ′.
The polarizer 3 is formed in contact with the dye layer 4. In the polarizing film 1 composed of these, the dye layer 4 side is protected by a protective film 5, and the polarizer 3 side is protected by a second protective film 5 ′.
The polarizing plate 6 ′ thus produced has a defect when it is wound in a roll shape by bonding the protective film 5 and the second protective film 5 ′ on the dye layer 4 and the polarizer 3 of the polarizing film 1. Generation can be suppressed and handling can be facilitated. The protective film 5 and the second protective film 5 ′ are bonded using a pressure-sensitive adhesive / adhesive. Here, in addition to an agent that cannot be peeled (an agent that causes peeling with material destruction), self-adhesion The protective film 5 and the second protective film 5 ′ may be bonded using an agent that can be peeled off without causing material destruction, such as a conductive polyethylene resin or a light release acrylic adhesive. Thereby, it becomes possible to peel off the protective film 5 and the second protective film 5 ′ later and directly attach them to a material with high heat dissipation.

  Since the polarizing plate 6 'of the present invention is formed by directly laminating the dye layer 4 on the polarizer 3 without providing a protective film, the heat dissipation efficiency is good. In addition, when light enters from the dye layer 4 side, the dye layer 4 is directly exposed to light, and the dye included in the polarizer 3 is not directly exposed to light. 3 can be suppressed.

FIG. 5 is a schematic view showing the polarizing plate 20 of the present invention. The polarizing plate 20 includes a substrate 21, a polarizer 3, a dye layer 4, and a protective film 5.
The polarizer 3 is formed in contact with the dye layer 4. In the polarizing film 1 made of these, the dye layer 4 side is protected by the protective film 5, and the polarizer 3 side is bonded to the substrate 21.
The polarizing film 1 is protected by the substrate 21 on the polarizer 3 side and the protective film 5 on the dye layer 4 side. Since the polarizer 3 is bonded to the substrate 21, higher heat dissipation can be realized.

FIG. 6 is a schematic view showing the polarizing plate 22 of the present invention. The polarizing plate 22 includes a substrate 21, a polarizer 3, a dye layer 4, and a second substrate 23.
The polarizer 3 is formed in contact with the dye layer 4. The polarizing film 1 composed of these is bonded to the substrate 21 on the polarizer 3 side and bonded to the second substrate 23 on the dye layer 4 side.
In the polarizing film 1, the polarizer 3 side is protected by the substrate 21, and the dye layer 4 side is protected by the second substrate 23. Since there is no protective film 5 that functions as a heat insulating layer, higher heat dissipation can be realized.

  The substrate 21 and the second substrate 23 included in the polarizing plate 20 and the polarizing plate 22 need to be a material that transmits visible light when the polarizing plate 20 and the polarizing plate 22 are used in a projection display device. Specifically, materials such as optical glass such as BK7, Pyrex (registered trademark), soda glass, alkali-free glass, quartz, sapphire, spinel, and magnesia can be used. The transparent substrate may be formed with a coating layer composed of a dielectric film, a metal film, or a combination of both for the purpose of preventing reflection, color separation, and polarization separation. Furthermore, a thin film layer containing fluorine for the purpose of preventing contamination may be provided on these outermost surfaces.

The heat transfer from the polarizing film 1 is performed through the substrate 21 in the polarizing plate 20 (FIG. 5) and through the substrate 21 and the second substrate 23 in the polarizing plate 22 (FIG. 6). In the polarizing plate 20 (FIG. 5), the transparent substrate is bonded to only one surface of the polarizing film 1, whereas in the polarizing plate 22 (FIG. 6), the transparent substrate is bonded to both surfaces of the polarizing film 1. It is preferable that a transparent substrate is bonded to both surfaces of the polarizing film 1 because heat transfer from both surfaces of the polarizing film 1 is promoted, so that the polarizing film 1 can be further cooled.
The substrate 21 or the substrate 23 is preferably made of a material having high thermal conductivity. For example, the thermal conductivity of quartz is about 8 W / (m · K), and the thermal conductivity of sapphire is about 28 W / (m · K), compared to about 1 W / (m · K) for amorphous glass. Have excellent thermal conductivity. Therefore, the substrate 21 and the second substrate 22 are preferably made of quartz, sapphire, magnesia, or spinel as a high thermal conductive material. In the polarizing plate 22 (FIG. 6), either one of the substrate 21 and the second substrate 22 only needs to be a high thermal conductive material, and the other remaining substrate is from the viewpoint of thermal conductivity, substrate cost, and optical characteristics. Further, it may be an amorphous glass transparent substrate mainly composed of quartz or silicon oxide.

An adhesive or a pressure-sensitive adhesive is used for bonding the polarizing film 1 and the substrate.
In order to improve the adhesion between the polarizing film 1 and the substrate, surface treatment such as plasma treatment, corona treatment, ultraviolet irradiation treatment, flame (flame) treatment, and saponification treatment may be appropriately performed on the adhesion surface. Examples of the saponification treatment include a method of immersing in an aqueous alkali solution such as sodium hydroxide or potassium hydroxide.

As the adhesive, an aqueous adhesive and a non-aqueous adhesive are used.
Examples of the water-based adhesive include an adhesive mainly composed of modified polyvinyl alcohol, or a vinyl acetate-based adhesive. Particularly preferred is an adhesive mainly composed of polyvinyl alcohol. For example, there is an adhesive that is cured by crosslinking a specially modified polyvinyl alcohol having an acetoacetyl group with glyoxal or zirconyl nitrate. Moreover, the adhesive agent which adds a hydrophilic epoxy resin to special modification polyvinyl alcohol, and is bridge | crosslinked is mentioned, As modified PVA, Goseifamer (brand name, Nihon Gosei Co., Ltd. product), Kuraray K polymer (brand name, (Manufactured by Kuraray Co., Ltd.).
Non-aqueous adhesives include acrylic resin adhesives, urethane resin adhesives, cyanoacrylate adhesives, silicone adhesives based on organopolysiloxane, and modified silicone adhesives based on polypropylene oxide. Etc.

As an adhesive, a general acrylic resin adhesive or a self-adhesive resin can be used.
Examples of the self-adhesive resin include self-adhesive resins such as polypropylene resin, polyethylene resin, and propylene elastomer resin. Examples of self-adhesive resins include general-purpose resins such as polypropylene resins and polyethylene resins, as well as tough selenium (trade name, manufactured by Sumitomo Chemical Co., Ltd.).
Adhesives and adhesives are selected as appropriate for the intended product, such as those with strong adhesion and adhesion that cause material destruction during peeling, or those that can be peeled off without destroying the adherend. Can be used.

FIG. 7 is a schematic view showing a projection type liquid crystal display device of the present invention.
The polarizing plate 142 and the polarizing plate 143 of the present invention are used in, for example, a projection type liquid crystal display device (projector). The details will be described by taking the optical system shown in FIG. 7 as an example.
A light bundle using a light source (for example, a high-pressure mercury lamp) 111 as a light source first passes through the first lens array 112, the second lens array 113, the polarization conversion element 114, and the superimposing lens 115, and thus has a cross section of the anti-light bundle. The brightness is made uniform and polarized.

  Specifically, the light bundle emitted from the light source 111 is divided into a number of minute light bundles by the first lens array 112 in which minute lenses 112a are arranged in a matrix. The second lens array 113 and the superimposing lens 115 are provided so that each of the divided light bundles irradiates the entire three liquid crystal display (LCD) panels 140R, 140G, and 140B to be illuminated, For this reason, the entire LCD panel incident side surface has substantially uniform illuminance.

  The polarization conversion element 114 is usually configured by a polarization beam splitter array, and is disposed between the second lens array 113 and the superimposing lens 115. As a result, random polarized light from the light source is converted into polarized light having a specific polarization direction in advance, thereby reducing the light loss at the incident-side polarizing plate described later, thereby improving the screen brightness.

  The light with uniform and polarized luminance is sequentially separated into red channel, green channel and blue channel by the dichroic mirrors 121, 123 and 132 for separating the three primary colors of RGB through the reflection mirror 122, respectively. The light enters the LCD panels 140R, 140G, and 140B.

  Regarding the LCD panels 140R, 140G, and 140B, the polarizing plate (incident side) 142 and the polarizing plate (exit side) 143 of the present invention are arranged on the incident side and the outgoing side, respectively.

  Here, in the polarizing plate of the present invention, it is necessary to install the dye layer 4 on the light source side. As a result, the light received by the dichroic dye that the polarizer 3 has can be dispersed, and the dye decomposition rate by the photochemical reaction can be reduced.

  A description will be given of two polarizing plates arranged on the incident side and the emission side with a liquid crystal panel sandwiched between the RGB optical paths. A polarizing plate (incident side) 142 and a polarizing plate (exit side) 143 arranged in each optical path are arranged in a configuration in which the absorption axes are orthogonal to each other, and each LCD panel 140R, 140G, 140B arranged in each optical path. It fulfills the function of converting the polarization state controlled for each pixel by the image signal into light quantity.

  The polarizing plate of the present invention has a configuration common to all the optical paths of the blue channel, the green channel, and the red channel, and is effective as a polarizing plate having excellent durability in any optical path, particularly in the blue channel and the green channel. It is valid.

  An optical image created by transmitting incident light with different transmittance for each pixel according to the image data of the LCD panels 140R, 140G, and 140B is synthesized by the cross dichroic prism 150, and is projected by the projection lens 170 to the screen 180. Is enlarged and projected.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Example 1]
Examples using a blue channel absorbing polarizer prepared by adsorbing a yellow dye exhibiting excellent dichroism in the blue region to a uniaxially stretched PVA resin as an optical member are shown below.

  First, a PVA film having an average degree of polymerization of about 2,400 and a saponification degree of 99.9 mol% or more and a thickness of 75 μm is uniaxially stretched about 5 times in a dry process, and further applied tension for stretching. After being immersed in pure water at 60 ° C. for 1 minute, it was immersed in an aqueous solution having a weight ratio of yellow dichroic dye (orange 39) / water of 0.05 / 100 at 74 ° C. for 60 seconds. Then, it was immersed in an aqueous solution having a boric acid / water weight ratio of 8.5 / 100 at 72 ° C. for 300 seconds. Subsequently, it is washed with pure water at 26 ° C. for 20 seconds and dried to obtain a polarizer having a dichroic dye adsorbed and oriented on a PVA film and having an absorption polarization transmittance of 0.1%. The polarizer is coated with a dichroic dye (Orange 39) PVA solution, coated to have a thickness of about 1 μm and an absorption polarization transmittance of about 50%, a dye layer is formed, and the polarizing film of the present invention Get.

  Furthermore, as a protective film, an 80 μm thick triacetyl cellulose film is bonded onto the pigment layer, and a resin film is bonded to a 0.5 mm thick quartz substrate via an acrylic adhesive having a thickness of 25 μm. The polarizing plate of the present invention is obtained.

[Comparative Example 1]
First, a PVA film having an average degree of polymerization of about 2,400 and a saponification degree of 99.9 mol% or more and a thickness of 75 μm is uniaxially stretched about 5 times in a dry process, and further applied tension for stretching. After being immersed in pure water at 60 ° C. for 1 minute, it was immersed in an aqueous solution having a weight ratio of yellow dichroic dye (orange 39) / water of 0.05 / 100 at 74 ° C. for 60 seconds. Then, it was immersed in an aqueous solution having a boric acid / water weight ratio of 8.5 / 100 at 72 ° C. for 300 seconds. Subsequently, it is washed with pure water at 26 ° C. for 20 seconds and then dried to obtain a polarizer in which dichroic dye is adsorbed and oriented on PVA. A triacetyl cellulose film having a thickness of 80 μm is bonded to both sides of the polarizer as a protective film to obtain a film composed of the polarizer and the protective film having an absorption polarization transmittance of 0.1%.
A PVA film having an average degree of polymerization of about 2,400 and a saponification degree of 99.9 mol% or more and a thickness of 75 μm is uniaxially stretched about 5 times in a dry manner and further subjected to tension for stretching at 60 ° C. And then immersed in an aqueous solution having a weight ratio of yellow dichroic dye (orange 39) / water of 0.0005 / 100 at 74 ° C. for 60 seconds. Then, it was immersed in an aqueous solution having a boric acid / water weight ratio of 8.5 / 100 at 72 ° C. for 300 seconds. Subsequently, it is washed with pure water at 26 ° C. for 20 seconds and then dried to obtain a dye layer in which the dichroic dye is adsorbed on PVA. A triacetyl cellulose film having a thickness of 80 μm is bonded to both sides of the dye layer as a protective film to obtain a film composed of the dye layer and the protective film having an absorption polarization transmittance of approximately 60%.
A film made of a polarizer and a protective film and a film made of a dye layer and a protective film are bonded to obtain a polarizing plate of a comparative example.

It is the schematic explaining the manufacturing method of the polarizing film 1 and the polarizing plate 6 of this invention. It is the schematic which shows the polarizing film 1 of this invention. It is the schematic which shows the polarizing plate 6 of this invention. It is the schematic which shows the polarizing plate 6 'of this invention. It is the schematic which shows the polarizing plate 20 of this invention. It is the schematic which shows the polarizing plate 22 of this invention. It is the schematic which shows the projection type liquid crystal display device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polarizing film 2 Resin film 3 Polarizer 4 Dye layer 5 Protective film 5 ′ Second protective film 6, 6 ′, 20, 22 Polarizing plate 11,15 Roll 12 Stretching device 13 Dyeing device 14 Coating device 21 Substrate 23 Second substrate DESCRIPTION OF SYMBOLS 111 Light source 112 1st lens array 112a Lens 113 2nd lens array 114 Polarization conversion element 115 Superimposition lens 121,123,132 Dichroic mirror 122 Reflection mirror 140R, 140G, 140B LCD panel 142,143 Polarizing plate 150 Cross dichroic prism 170 Projection lens 180 screen

Claims (3)

  A method for producing a polarizing film, comprising: stretching a resin film; dipping in a dye solution; and applying the dye-containing resin solution to at least one surface of a polarizer that can be obtained by dipping in a boric acid solution.   The manufacturing method of the polarizing plate which bonds a protective film or a board | substrate to the at least single side | surface of the polarizing film manufactured by the manufacturing method of the polarizing film of Claim 1. A light source;
A polarizing plate produced by the method for producing a polarizing plate according to claim 2;
Separating means for separating light that has passed through the polarizing plate,
A projection-type image display device in which a polarizing plate is provided so that light enters from a surface side coated with a dye-containing resin solution and exits from a polarizer side.

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