JP2002286932A - Method for manufacturing polarizing film or protective film for polarizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a polarizing film with improved production efficiency by forming an antireflective layer in a web state by a dry process when a web type polarizing film or a protective film is subjected to the antireflective treatment. SOLUTION: In the method for manufacturing a polarizing film, high refractive index layers and low refractive index layers are alternately laminated to form an antireflection layer on at least one surface of a web type polarizing film composed of a polarizer protected by a protective film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an anti-reflection layer on a web-like polarizing film by a roll-to-roll method or a stepping roll method.

[0002]

2. Description of the Related Art A polarizing film for a liquid crystal display (hereinafter referred to as LCD) is sometimes subjected to a processing for providing an antireflection layer for preventing reflection. In particular, a polarizing film for an LCD used outdoors or the like is required to have a high-performance antireflection function. In order to provide such a high-performance anti-reflection function, a physical vapor deposition (PVD) method called a dry process, a chemical vapor deposition (C)
An antireflection layer is formed by the VD) method. Usually, in this case, a web-like polarizing film in which a protective film coated with a hard organic resin on one side is bonded, or a protective film before bonding to a web-shaped polarizer in which a hard organic resin is coated on one side. Is cut into a predetermined size to form a single-wafer shape, and an antireflection layer is formed by the above-described method.

However, by cutting the web before forming the antireflection layer, chips of the polarizer film, the protective film, or the hard organic resin are generated. These chips may cause partial defects of the antireflection layer or poor appearance of the polarizing film by being attached to the polarizing film or the protective film, which may lower the work and production efficiency and increase the cost. Was.

Further, when forming an anti-reflection layer by a dry process, the atmosphere must be evacuated in order to form the anti-reflection layer. It took a long time to exhaust air, and productivity was low for single wafers. Further, in forming the anti-reflection layer, it takes time until the conditions for forming the layer are stabilized, so if it is a single wafer, it becomes a batch process, which lowers the work and production efficiency and increases the cost. .

In particular, a web-like protective film coated with a hard organic resin or a modified film to which a protective film is attached becomes brittle while being hardened. It is easily damaged by small scratches. Further, when a film is formed on the web-like film coated with the hard organic resin by a dry process such as a PVD method or a CVD method, a thermal load is applied, so that the film is easily broken or cut.

When a triacetylcellulose film (TAC film) having a small optical distortion is used as a protective film for a polarizer, there is a great tendency for breakage and cutting due to the above-mentioned phenomenon. In particular, a web-like TAC film coated with a hard organic resin is easily broken or cut due to a scratch at an end or the like.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and when an anti-reflection processing is performed on a polarizing film or a protective film, an anti-reflection layer is formed in a web shape. Is provided by a dry process to provide a method for manufacturing a polarizing film with improved productivity efficiency.

[0008]

According to the first aspect of the present invention, a high refractive index layer and a low refractive index layer are alternately laminated on at least one surface of a polarizing film having a structure in which a polarizer is protected by a protective film. And a method for producing a polarizing film, comprising providing an antireflection layer.

According to the second aspect of the present invention, a web-like protective film having an anti-reflection layer in which high-refractive-index layers and low-refractive-index layers are alternately laminated on at least one surface of a web-like polarizer is laminated. This is a method for producing a polarizing film.

According to a third aspect of the present invention, there is provided a hard organic resin layer containing at least one or more of an acrylic resin, a urethane resin, and an epoxy resin between the protective film and the antireflection layer. The method for producing a polarizing film according to claim 1, wherein are laminated.

The invention according to claim 4 is characterized in that at least one high refractive index layer or one low refractive index layer constituting the antireflection layer is provided. A method for producing a polarizing film according to any one of the above.

According to a fifth aspect of the present invention, there is provided a water-repellent or water-repellent layer comprising at least one of a perfluoroalkyl-containing silane compound, a perfluoropolyether group-containing silane compound and a fluorine-containing silicone compound on the antireflection layer. The method for producing a polarizing film according to any one of claims 1 to 4, wherein an antifouling layer is laminated.

The invention according to claim 6, wherein the high refractive index layer of the antireflection layer has a refractive index of 1.85 or more. It is a manufacturing method of. The invention according to claim 7, wherein the low-refractive-index layer of the antireflection layer has a refractive index of 1.70 or less, the method for producing a polarizing film according to any one of claims 1 to 5, wherein:

The invention according to claim 8 is the method for producing a polarizing film according to any one of claims 1 to 7, wherein the protective film is made of a triacetyl cellulose film.

According to a ninth aspect of the present invention, the high refractive index layer is made of titanium oxide, zirconium oxide, tantalum oxide, zinc oxide, niobium oxide, hafnium oxide, cerium oxide,
The method for producing a polarizing film according to any one of claims 1 to 8, comprising at least one of zinc oxide, indium oxide, and tin oxide, or a mixture selected from two or more thereof.

According to a tenth aspect of the present invention, there is provided a polarizing film formed on a web-like polarizing film according to the first to ninth aspects, wherein the low refractive index layer is made of silicon dioxide, magnesium fluoride or calcium fluoride. It is a manufacturing method.

[0017] In the invention according to claim 11, the antireflection layer is formed by physical vapor deposition (P) including vapor deposition or sputtering.
This is a method for producing a polarizer protective film formed on a web-like polarizing film, which is produced by using a VD) method or a chemical vapor deposition (CVD) method.

According to a twelfth aspect of the present invention, there is provided a polarizer protective film, wherein an antireflection layer in which high refractive index layers and low refractive index layers are alternately laminated is provided on at least one surface of the polarizer protective film. This is a method for producing a protective film.

According to a thirteenth aspect of the present invention, there is provided a hard organic material containing at least one or more of an acrylic resin, a urethane resin, and an epoxy resin between the web-like protective film and the antireflection layer. The method for producing a protective film for a polarizer according to claim 12, wherein a resin layer is laminated.

According to a fourteenth aspect of the present invention, the high-refractive-index layer and the low-refractive-index layer constituting the antireflection layer each have one
14. The method for producing a protective film for a polarizer according to claim 12, wherein at least one is provided.

According to a fifteenth aspect of the present invention, the anti-reflection layer contains at least one of a perfluoroalkyl-containing silane compound, a perfluoropolyether group-containing silane compound, and a fluorine-containing silicone compound. 2. The antifouling layer is laminated.
15. A method for producing a protective film for a polarizer according to any one of 2 to 14.

According to a sixteenth aspect of the present invention, the high refractive index layer of the antireflection layer has a refractive index of 1.85 or more. This is a method for producing a protective film for use.

The invention according to claim 17 is the polarizer according to any one of claims 12 to 15, wherein the low refractive index layer of the antireflection layer has a refractive index of 1.70 or less. This is a method for producing a protective film.

The invention according to claim 18 is the method for producing a protective film for a polarizer according to any one of claims 12 to 17, wherein the web-like protective film is made of a triacetyl cellulose film. It is.

The invention according to claim 19 is that the high refractive index layer is made of titanium oxide, zirconium oxide, tantalum oxide,
The polarizer protective film according to any one of claims 12 to 18, comprising at least one of zinc oxide, indium oxide, niobium oxide, hafnium oxide, cerium oxide, zinc oxide, and tin oxide, or a mixture selected from two or more thereof. It is a manufacturing method of.

According to a twentieth aspect of the present invention, there is provided a polarizer formed on a web-like polarizing film according to the twelfth to nineteenth aspects, wherein the low refractive index layer is made of silicon dioxide, magnesium fluoride or calcium fluoride. This is a method for producing a protective film.

According to a twenty-first aspect of the present invention, the antireflection layer is formed by physical vapor deposition (P) including vapor deposition or sputtering.
21. The method for producing a protective film for a polarizer according to claim 12, wherein the protective film is produced by using a VD method or a chemical vapor deposition (CVD) method.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same reference numerals indicate the same or equivalent components. FIG. 1 is an explanatory diagram illustrating a polarizing film provided with an antireflection layer of one embodiment of the present invention. FIG. 2 is a cross-sectional view showing a laminated structure of the polarizing film of FIG. The structure is such that a hard organic resin layer 3, an antireflection layer 4, and an antifouling layer 5 are laminated on a web-shaped polarizing film 2 in this order.

Here, the antireflection layer 4 has a structure in which high refractive index layers and low refractive index layers are alternately laminated, and the high refractive index layer 41
And the low refractive index layer 42 are preferably composed of a total of four predetermined refractive index layers alternately stacked. In this case, each of the high-refractive-index layers 41 and the low-refractive-index layers 42 is set to a predetermined optical film thickness (n × d (where n is a refractive index and d is a geometric film thickness)). And exhibit a desired anti-reflection function. For example, the refractive index (n) of the high refractive index layer 41 is set to 1.
The refractive index (n) of the low refractive index layer 42 is set to 1.70 or less, preferably 1.60 or less.

Here, the high refractive index layer 41 and the low refractive index layer 42
FIG. 2 shows the number of layers of the high refractive index layer 41 and the low refractive index layer 4.
In this example, each of No. 2 and No. 2 has a total of four layers.
As described above, it is preferable to use two or more layers because a region having a reflectance of 0.5% or less in a wavelength range of 470 nm to 650 nm can be expanded.

As a material for forming the high refractive index layer 41, various dielectrics and conductive materials can be appropriately selected and used. Titanium oxide, zirconium oxide, tantalum oxide, zinc oxide, indium oxide, niobium oxide, One of hafnium oxide, cerium oxide, and tin oxide, or a mixture selected from two or more of them can be used. On the other hand, as a material for forming the low refractive index layer 42, silicon dioxide, magnesium fluoride, calcium fluoride, or the like can be used.

As a method of forming each layer of the antireflection layer 4, any film forming method can be adopted as long as the film can be formed without damaging the polarizing film 2 and other layers. For example, a PVD method such as a sputtering method or an evaporation method can be used. In this case, reactive vapor deposition or assist vapor deposition using plasma, ion beam, or the like may be performed as appropriate. Further, a CVD method in which the gas composition is appropriately changed can also be used.

In the present invention, the structure other than the above-mentioned anti-reflection layer 4 can be formed in the same manner as a known anti-reflection film. However, it is preferable that the polarizing film 2 and the hard organic resin layer be formed as described below. An antifouling layer 5 is provided on 3 and the outermost layer.

The polarizing film 2 generally has a structure in which a polarizing element is protected by a protective film. Since this protective film is required to have no birefringence, the constituent material thereof is preferably, for example, polycarbonate, triacetyl cellulose, polyether sulfone, polymethyl acrylate, or the like. Further, it may be formed from a general-purpose film material such as polyethylene terephthalate. The thickness of these films is selected according to the application.

The hard organic resin layer 3 may be provided as needed in order to impart a desired hardness to the polarizing film 2.
It is desirable that the hard organic resin layer 3 is transparent and has a refractive index equal to the refractive index n of the polarizing film 2.
However, the refractive index n of the polarizing film 2 is ± 0.05.
Any difference within is acceptable. The thickness of the hard organic resin layer 3 is set as long as the desired hardness can be imparted to the polarizing film 2.
Although not particularly limited, 10 points are considered in terms of optical characteristics and flexibility.
μm or less is preferable, 1 to 7 μm is more preferable, and 3 to 7 μm is more preferable.

The material of the hard organic resin layer 3 is not particularly limited as long as required properties such as transparency, adhesion and hardness are satisfied. For example, it can be formed from a resin mainly composed of an acrylic resin, a urethane-based resin, an epoxy-based resin, or the like. Further, these resins may be configured to contain an additive. Here, as the additive, a transparent pigment that scatters light, a transparent powder, or the like can be used. Such transparent pigments include, for example, inorganic compounds such as titanium oxide, silicon oxide, zinc oxide, and aluminum oxide; inorganic salts such as barium sulfate; magnesium fluoride;
Fluoride such as calcium fluoride can be exemplified. Further, as the transparent powder, resin powders such as polydivinylbenzene, polystyrene, and polytetrafluoroethylene, hollow beads composed of these resins, or surface treatment of these resins or the surfaces of the hollow beads thereof. The applied powder can also be used. The size of such a transparent powder is desirably about 3 μm so that it can be dispersed in the transparent resin constituting the hard organic resin layer 3 and can be smoothly and uniformly applied on the protective film 2.

The antifouling layer 5 is provided on the antireflection layer 4 as needed in order to protect the antireflection layer 4 and enhance antifouling performance. As a material for forming the antifouling layer 5,
There is no particular limitation as long as the function of the antireflection layer 4 is not hindered and the required performance as an antifouling layer is satisfied. Usually, a compound having a hydrophobic group can be preferably used. As specific examples, a perfluoroalkyl-containing silane compound, a perfluoropolyether group-containing silane compound, and a fluorine-containing silicone compound can be used. The thickness of the antifouling layer 5 is not particularly limited, but is usually preferably 20 nm or less, more preferably 10 nm or less. The antifouling layer 5 is formed by, for example, using a physical vapor deposition method such as vapor deposition or sputtering, a chemical vapor deposition method such as CVD, or a special wet coating, depending on the material to be formed. Can be.

Here, the structure in which the anti-reflection layer is provided with the protection film provided has been described. However, after the anti-reflection layer is provided on the protection film, the polarizing element and the protection film may be bonded.

FIG. 3 shows a polarizing film 2 according to one embodiment of the present invention.
FIG. 3 is an explanatory view schematically showing a method of providing an antireflection layer 4 thereon.

The hard organic resin 3 is applied to the web-shaped polarizing film 2, and the antireflection layer 4 is formed on the hard organic resin layer 3 as it is. The winding direction of the web is changed according to the intended number of layers of the antireflection layer 4, and the web-shaped polarizing film 2 is reciprocated in the film forming chamber. On the hard organic resin layer side 3 of the polarizing film 2. Further, considering production efficiency, it is desirable that the method of laminating the antifouling layer 5 is also constituted by a web-like protective film having the antireflection layer 4.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. <Example 1> An antireflection film having a layer constitution shown in Table 1 was produced as follows. First, a web-shaped polarizing film 2 in which a polarizer was protected by a protective film was prepared. As the hard organic resin layer 3, an ultraviolet-curable acrylic resin was used, and the hard organic resin layer 3 was formed on the protective film 2 in a web form by a die coating method. Next, titanium dioxide was prepared as a material for forming the high refractive index layer 41, and silicon dioxide was prepared as a material for forming the low refractive index layer 42, and these were formed into web-like polarized light with the optical film thickness (nd value) shown in Table 1. A film was formed on the film. In this case, titanium dioxide and silicon dioxide are:
It was formed by a plasma assisted deposition method. For the antifouling layer 5, 5n of perfluoroalkylsilane is deposited by CVD.
m was formed.

[0042]

[Table 1]

FIG. 4 shows the visible spectrum of the obtained antireflection film. 550 of this web-shaped polarizing film
The reflectivity in nm was 0.5%. Also, 100
When the number of film formation failure sites with a size of μm or more was counted, 5
Pieces / m ² .

<Comparative Example 1> A web-like polarizing film 2 in which a polarizer was protected by a protective film was prepared. As the hard organic resin layer 3, an ultraviolet curable acrylic resin was used, and the hard organic resin layer 3 was applied on the polarizing film 2 in a web form by a die coating method. This polarizing film is 200 mm × 20
The film was cut into 0 mm, and an antireflection layer having the film configuration shown in Table 1 was formed in the same manner as in Example 1. An antifouling layer was formed in the same manner as in Example 1. FIG. 5 shows the visible spectrum of the obtained antireflection film. The reflectance at 550 nm of this polarizing film was 0.5%. In addition, when the number of defective film formation sites having a size of 100 μm or more was counted, it was 300 / m ² .

Example 2 An antireflection film having the layer structure shown in Table 2 and FIG. 6 was produced as follows. First, a web-like triacetyl cellulose film was prepared as a web-like protective film 12 for a polarizing film. As the hard organic resin layer 3, an ultraviolet curable acrylic resin was used, and the hard organic resin layer 3 was applied on the protective film 12 in a web form by a die coating method. On the other hand, titanium dioxide as a material for forming the high-refractive-index layer 41 and silicon dioxide as a material for forming the low-refractive-index layer 42 were prepared. A film was formed on the film. In this case, titanium dioxide and silicon dioxide were formed by a plasma assisted vapor deposition method. Next, the antifouling layer 5
In this example, a perfluoroalkylsilane was deposited to a thickness of 5 nm by a CVD method.

[0046]

[Table 2]

FIG. 7 shows the visible spectrum of the obtained antireflection film. 550 of this web-shaped protective film
The reflectivity in nm was 0.5%. Also, 100
When the number of film formation failure sites with a size of μm or more was counted, 5
Pieces / m ² .

Comparative Example 2 A web-like triacetyl cellulose film was prepared as a web-like protective film 12 for a polarizing film. As the hard organic resin layer 3,
A UV-curable acrylic resin was used and applied on the protective film 2 by a die coating method in a web form. The protective film was cut into 200 × 200 mm ² , and an antireflection layer having the film configuration shown in Table 2 was formed in the same manner as in Example 2. An antifouling layer was also constructed in the same manner as in Example 2. FIG. 8 shows the visible spectrum of the obtained antireflection film. The reflectance of this web-shaped protective film at 550 nm is 0.1.
5%. Further, when the number of defective film formation sites having a size of 100 μm or more was counted, it was 300 / m ² .

[0049]

According to the present invention, since the antireflection layer is formed directly on the web-like polarizing film or the protective film, there is no possibility that the polarizing film may be damaged in the manufacturing process, so that the antireflection performance of visible light is improved. It is possible to obtain a polarizing film and a protective film for a polarizer having an excellent antireflection function with less appearance defects and good production efficiency.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of a web-shaped polarizing film.

FIG. 2 is a cross-sectional view illustrating an example of a laminated configuration of a web-shaped polarizing film.

FIG. 3 is an explanatory view showing a production process of a web-shaped polarizing film.

FIG. 4 is a graph showing a visible spectrum of the web-like polarizing film of Example 1.

FIG. 5 is a graph showing a visible spectrum of the web-like polarizing film of Comparative Example 1.

FIG. 6 is an explanatory view showing an example of a laminated structure of a web-like polarizer protective film.

FIG. 7 is a graph showing the visible spectrum of the web-shaped protective film for a polarizer of Example 2.

FIG. 8 is a graph showing the visible spectrum of the web-shaped protective film for a polarizer of Comparative Example 2.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Web-shaped polarizing film 2 Polarizing film 3 Hard organic resin layer 4 Antireflection layer 41 High refractive index layer 42 Low refractive index layer 5 Antifouling layer 6 Vacuum device 7 Winding room 8 Film forming room 9 Polarizing film 10 Roll to wind 11 Roll to unwind 12 Protective film for web polarizer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Dai Ito 1-5-1, Taito, Taito-ku, Tokyo Inside Toppan Printing Co., Ltd. (72) Inventor Haruo Uyama 1-15-1 Taito, Taito-ku, Tokyo Letterpress F-term (reference) in Printing Co., Ltd. 2H049 BA02 BB33 BB62 BB65 BC22 2K009 AA07 AA15 BB28 CC03 CC24 CC33 CC35 CC42 DD02 DD03 DD04 EE05 5G435 AA00 AA01 AA17 FF02 FF05 HH03 KK07

Claims (21)

[Claims] An anti-reflection layer comprising a high refractive index layer and a low refractive index layer alternately laminated on at least one surface of a web-like polarizing film having a structure in which a polarizer is protected by a protective film. Of producing a web-shaped polarizing film. 2. A web-shaped polarizer comprising at least one surface of a web-shaped polarizer and a web-shaped protective film provided with an antireflection layer in which high-refractive-index layers and low-refractive-index layers are alternately stacked. A method for producing a polarizing film. 3. A hard organic resin layer containing at least one or more of an acrylic resin, a urethane resin, and an epoxy resin is laminated between the protective film and the antireflection layer. The method for producing a polarizing film according to claim 1, wherein: 4. The polarizing film according to claim 1, wherein at least one high refractive index layer or one low refractive index layer constituting the antireflection layer is provided. Manufacturing method. 5. A water-repellent or antifouling layer containing at least one of a perfluoroalkyl-containing silane compound, a perfluoropolyether group-containing silane compound and a fluorine-containing silicone compound is laminated on the antireflection layer. The method for producing a polarizing film according to any one of claims 1 to 4, wherein: 6. The method for manufacturing a polarizing film according to claim 1, wherein the high refractive index layer of the antireflection layer has a refractive index of 1.85 or more. 7. The low refractive index layer of the antireflection layer has a refractive index of 1.
The method for producing a polarizing film according to any one of claims 1 to 5, wherein the number is 70 or less. 8. The method for producing a polarizing film according to claim 1, wherein said protective film comprises a triacetyl cellulose film. 9. The high refractive index layer is formed of at least one of titanium oxide, zirconium oxide, tantalum oxide, zinc oxide, niobium oxide, hafnium oxide, cerium oxide, zinc oxide, indium oxide, and tin oxide. The method for producing a polarizing film according to any one of claims 1 to 8, comprising a mixture selected from the group consisting of: 10. The method for producing a polarizing film formed on a web-like polarizing film according to claim 1, wherein the low refractive index layer is made of silicon dioxide, magnesium fluoride or calcium fluoride. 11. The method according to claim 11, wherein the anti-reflection layer is produced by using a physical vapor deposition (PVD) method including vapor deposition or sputtering or a chemical vapor deposition (CVD) method. A method for producing the formed protective film for a polarizer. 12. A web-like polarizer protective film comprising a web-like polarizer protective film provided on at least one side with an antireflection layer in which high refractive index layers and low refractive index layers are alternately laminated. Film production method. 13. A hard organic resin layer containing at least one or more of an acrylic resin, a urethane resin or an epoxy resin is laminated between the web-like protective film and the antireflection layer. Characterized by the fact that
A method for producing the web-like protective film for a polarizer according to claim 12. 14. The polarizer according to claim 12, wherein at least one high refractive index layer or one low refractive index layer constituting the antireflection layer is provided. Production method of protective film for medical use. 15. A water-repellent or antifouling layer containing at least one of a perfluoroalkyl-containing silane compound, a perfluoropolyether group-containing silane compound and a fluorine-containing silicone compound is laminated on the antireflection layer. The method for producing a protective film for a polarizer according to any one of claims 12 to 14, wherein: 16. The method for producing a polarizer protective film according to claim 12, wherein the high refractive index layer of the antireflection layer has a refractive index of 1.85 or more. 17. The method for producing a protective film for a polarizer according to claim 12, wherein the low refractive index layer of the antireflection layer has a refractive index of 1.70 or less. 18. The method for producing a protective film for a polarizer according to claim 12, wherein the web-like protective film is made of a triacetyl cellulose film. 19. The high-refractive-index layer is formed of at least one of titanium oxide, zirconium oxide, tantalum oxide, zinc oxide, niobium oxide, hafnium oxide, cerium oxide, zinc oxide, indium oxide, and tin oxide. The method for producing a protective film for a polarizer according to any one of claims 12 to 18, comprising a mixture selected from the group consisting of: 20. The low refractive index layer is made of silicon dioxide, magnesium fluoride or calcium fluoride.
10. The method for producing a polarizer protective film formed on the web-like polarizing film according to 9. 21. The method according to claim 12, wherein the antireflection layer is manufactured by using a physical vapor deposition (PVD) method including vapor deposition or sputtering or a chemical vapor deposition (CVD) method. A method for producing a protective film for a polarizer.