JP4520445B2 - Wire grid polarizer - Google Patents

Description

  The present invention relates to a wire grid polarizer having a fine concavo-convex grating with a pitch of 150 nm or less.

  With the recent development of photolithography technology, it has become possible to form patterns with a very narrow pitch. If a pattern having such a narrow pitch, particularly a light wavelength level pitch, can be formed, members and products having such a narrow pitch pattern can be used not only in the semiconductor field but also in the optical field. it can. In particular, in the optical field, members and products having a fine concavo-convex lattice with a pitch of 150 nm or less have a wide range of applications, and there is an increasing demand for such members and products.

  For example, in the optical field, if the distance between metal lines can be made considerably smaller than the wavelength of light, it can be considered to be used as a reflective polarizing plate. Such a polarizing plate is desirable also from the viewpoint of effective use of light because it can reflect and reuse light that does not transmit. However, at present, it is impossible to realize a fine concavo-convex lattice having a pitch of 150 nm or less.

  In recent years, a wire grid polarizer having a fine concavo-convex grating with a very narrow pitch has been developed (Patent Document 1). This wire grid polarizer is configured by forming a conductive element on a convex portion of a glass substrate having a plurality of convex portions via a transparent dielectric film. However, since the above-described wire grid polarizer has a fine concavo-convex grid with a very narrow pitch, if something touches the fine concavo-convex grid in handling, the fine concavo-convex grid is deformed, and the optical as a polarizer It is possible that the characteristics will be affected.

Therefore, for the purpose of protecting the fine concavo-convex grating, it has been studied to cover the surface with a protective plate such as glass while keeping the refractive index of the space between the wires low as an embedded wire grid polarizer (patent) Reference 2).
Special table 2003-502708 gazette Special Table 2003-519818

  However, the embedded wire grid polarizer as described above has a large decrease in polarization performance due to the embedded, and there are structural limitations in order to use it optimally. In addition, there is no disclosure about a method for coupling between the wire and the protective plate.

  The present invention has been made in view of such points, has a fine concavo-convex grating with a pitch of 150 nm or less, has no structural limitation, exhibits an excellent degree of polarization over a wide band in the visible light region, and is fine. It is an object of the present invention to provide a wire grid polarizing plate capable of protecting an uneven grating and a liquid crystal display device using the same.

The wire grid polarizing plate of the present invention includes a transparent base material having a grid-like convex portion, a metal wire layer provided on a region of the base material including the grid-like convex portion, and a tip portion of the metal wire layer A protective film having a pressure-sensitive adhesive layer that is in close contact with the substrate, wherein the pitch of the base material is 150 nm or less, and the adhesive force of the pressure-sensitive adhesive layer to the metal wire layer is a peel force in a direction of 180 degrees with respect to a smooth surface. 0.02 N / 25 mm to 1 N / 25 mm, and the pressure-sensitive adhesive layer has a fluidity such that the transmitted light intensity at the time of crossed Nicols with respect to linearly polarized light having a wavelength of 500 nm is twice or less that when the protective film is not provided. It is comprised with the elastic material which has .

In the wire grid polarizer of the present invention, before Symbol elastic material is preferably a crosslinked silicone rubber or acrylic adhesive.

In the wire grid polarizing plate of the present invention, the pressure-sensitive adhesive layer preferably has a thickness of 1 μm to 10 μm.

  In the wire grid polarizing plate of the present invention, the protective film preferably has a phase difference of 20 nm or less.

In the wire grid polarizing plate of the present invention, it is preferable that the protective film has a retardation of 80 nm or more, and the protective film also serves as a retardation film. Moreover, in the wire grid polarizing plate of this invention, it is preferable that the said protective film is selected from the group which consists of COP, PC, PS, TAC, and PET. Moreover, in the wire grid polarizing plate of this invention, it is preferable that the adhesive force with respect to the said metal wire layer of the said adhesive layer is 0.02N / 25mm-1N / 25mm.

  According to the present invention, the transparent base material having the lattice-shaped convex portions, the metal wire layer provided on the region including the lattice-shaped convex portions of the base material, and the tip portion of the metal wire layer are in close contact with each other. And a protective film having a pressure-sensitive adhesive layer, so that it has a fine concavo-convex lattice with a pitch of 150 nm or less, has no structural restrictions, exhibits an excellent degree of polarization over a wide band in the visible light region, and is fine. A wire grid polarizing plate that can protect the uneven grating can be obtained.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view showing a part of a wire grid polarizer according to an embodiment of the present invention. The wire grid polarizing plate shown in FIG. 1 includes a transparent base material 1 having a grid-like convex portion 1a, a metal wire layer 2 provided on a region of the base material 1 including the grid-like convex portion 1a, and the metal It is mainly comprised from the protective film 3 provided with the protective film base material 3a which has the adhesive layer 3b which contacts the front-end | tip part of the wire layer 2. FIG. Here, the base material 1 is comprised from the base base material 11 and the ultraviolet curable resin layer 12 provided on the base base material 11 so that it may have the grid | lattice-like convex part 1a. In addition, if the base material 1 has the grid | lattice-shaped convex part 1a for providing the metal wire layer 2, you may be comprised by the single layer and using a resin base material, a glass substrate, etc. suitably. it can.

  The base substrate 11 is composed of a thermoplastic resin such as PET (polyethylene terephthalate) resin, PMMA (polymethyl methacrylate) resin, PC (polycarbonate) resin, PS (polystyrene) resin, COP (cycloolefin polymer). And resin such as TAC (triacetyl cellulose) resin, glass and the like. As the ultraviolet curable resin constituting the ultraviolet curable resin layer 12, an ultraviolet curable resin such as acrylic, epoxy, or urethane can be used.

  When the base material 1 is constituted by a single layer, examples of the base material 1 include thermoplastic resins such as PET resin, PMMA resin, PC resin, PS resin, and COP, resins such as TAC resin, and glass. be able to.

  In the case where the grid-like convex portions 1a are provided on the ultraviolet curable resin, for example, a grid-like convex shape having a pitch of 150 nm or less is obtained by applying a grid-like convex shape to the thermoplastic resin substrate and then stretching the substrate. A base material having a convex portion is obtained. Then, a mold is produced using the base material having the grid-like convex portions obtained in this manner, and the UV-curable resin is UV-cured while pressing the mold against the UV-curable resin, and the mold lattice The convex portion is transferred to the ultraviolet curable resin to provide the lattice-shaped convex portion 1a.

  In addition, when the lattice-shaped convex portion 1a is provided on the thermoplastic resin to form a single-layer substrate, the shape of the lattice-shaped convex portion is formed on the thermoplastic resin using a mold having a lattice-shaped convex portion having a pitch of 150 nm or less. Or a method of obtaining a base material having a pitch of 150 nm or less by subjecting the thermoplastic resin to thermal transfer or stretching the thermoplastic resin. Such stretching of the thermoplastic resin substrate is described in Japanese Patent Application No. 2006-2100 of the present applicant. All this content is included here. Moreover, when providing the grid | lattice-like convex part 1a in a glass substrate etc., normal patterning methods, such as photolithography and an etching, may be used, for example.

  The pitch of the grid-like convex portions 1a of the substrate 1 is 120 nm or less, preferably 80 nm to 120 nm, considering polarization characteristics over a wide band in the visible light region. The smaller the pitch is, the better the polarization characteristics are. However, for visible light, sufficient polarization characteristics can be obtained at a pitch of 80 nm to 120 nm. If the polarization characteristics of short wavelength light in the vicinity of 400 nm are not important, the pitch can be increased to about 150 nm. When the thermoplastic resin is used for the base material 1, the pitch of the grid-like convex parts 1 a can be controlled by adjusting the conditions of the stretching process to be performed after the lattice-like convex part shape is imparted to the base material 1.

  In addition, a dielectric layer may be provided on the lattice-shaped convex portion 1a. In particular, when a resin substrate is used as the substrate, it is preferable to provide a dielectric layer. When the dielectric layer covers the side surface of the lattice-shaped convex portion 1a, the contact area between the lattice-shaped convex portion 1a and the dielectric layer is increased. Thereby, the adhesiveness between the grid | lattice-like convex part 1a and a dielectric material layer can be improved. Since the adhesion between the grid-like convex portion 1a and the dielectric layer is improved as described above, the metal wire layer 2 can be firmly erected on the grid-like convex portion 1a. Even if the layer 2 is provided thick and the height of the entire wire (lattice-shaped convex portion 1a + metal wire layer 2) is increased, the strength against the external force of the wire can be kept high. The height of the lattice-shaped convex portion 1a increases the adhesion strength with the dielectric layer, and considering the selective stacking of the dielectric layer on the lattice-shaped convex portion 1a, the pitch between the lattice-shaped convex portions is It is preferably 0.5 to 1.5 times, and particularly preferably 0.8 to 1.5 times the pitch between the lattice-shaped convex portions. The total height of the lattice-shaped convex portion 1a and the dielectric layer is preferably 100 nm to 300 nm, and particularly preferably 150 nm to 250 nm in consideration of strength, polarization performance, and the like.

  The metal constituting the metal wire layer 2 is preferably a material having a high light reflectance, and examples thereof include aluminum and silver. The height of the metal wire layer 2 is preferably 120 nm to 220 nm, particularly 140 nm to 200 nm, in consideration of the degree of polarization, transmittance, and the like. In addition, the width of the wire is preferably 35% to 60% of the pitch between the lattice-shaped convex portions in consideration of the degree of polarization, transmittance, and the like. The ratio between the height and width (aspect ratio) of the wire is preferably 2 to 5, and particularly preferably 2 to 3.5. The method for forming the metal wire layer 2 is appropriately selected in consideration of the material constituting the metal wire layer 2 and the material constituting the substrate. For example, a vacuum deposition method or the like can be used.

  There is no limitation on the cross-sectional shape of the concave portions of the fine concavo-convex lattice formed by the lattice-like convex portions 1a and the plurality of lattice-like convex portions. These cross-sectional shapes may be sinusoidal, such as trapezoidal, rectangular, square, prismatic, and semicircular. Here, the sinusoidal shape means that it has a curved portion formed by repetition of a concave portion and a convex portion. In addition, the curved part should just be a curved curve, for example, the shape which has a constriction in a convex part is also included in a sine wave form.

  When the base material is a resin base material, it is preferable to provide a dielectric layer between the base material and the metal layer, from the viewpoint of facilitating the dielectric layer to cover at least part of the lattice-shaped convex portions and the side surfaces thereof, It is preferable that the end portion, apex, and valley of the cross-sectional shape have a gently curved shape having a relatively large curvature. When a resin base material is used, the cross-sectional shape is more preferably a sine wave shape from the viewpoint of increasing the adhesion strength between the resin base material and the dielectric layer.

  The pressure-sensitive adhesive layer 3b of the protective film 3 has a bonding force necessary for bonding the metal wire layer 2 and the protective film substrate 3a, and follows the shape of the top of the wire of the metal wire layer 2 to follow the wire. Selectively contacts the top. That is, when the protective film 3 is provided on the metal wire layer 2, the pressure-sensitive adhesive layer 3b is in close contact with the metal wire layer 2 without entering between the wires of the metal wire layer 2, and the protective film 3 is attached to the metal wire layer. When removing from 2, the metal wire layer 2 has a function of removing the protective film 3 without causing the wires of the metal wire layer 2 to peel off from the substrate 1. In addition, the pressure-sensitive adhesive layer 3b has such a property that the adhesion state with the metal wire layer 2 does not change even if it is left for a long time due to such a function. Therefore, the adhesive force of the pressure-sensitive adhesive layer 3b to the metal wire layer 2 is sufficient to securely fix the protective film 3 when the protective film 3 is provided, and from the metal wire layer 2 of the pressure-sensitive adhesive layer 3b. The peeling force does not affect the metal wire layer 2 formed on the lattice-shaped convex portion 1a, for example, it is separated from the metal wire layer 2 without deforming the wire or peeling the wire from the substrate 1. There is enough power to. For example, the adhesive strength of the pressure-sensitive adhesive layer 3b to the metal wire layer 2 is 0.02 N / 25 mm to 1 N / 25 mm, preferably 0.03 N / 25 mm to 0 in terms of a peel value in the direction of 180 degrees with respect to a smooth surface such as glass. .5 N / 25 mm. Thereby, in the wire grid polarizing plate of this invention, it becomes possible to stick and peel the protective film 3 on the base material 1 which has the metal wire layer 2 many times.

  Examples of the material constituting the pressure-sensitive adhesive layer 3b include an elastic material having a considerably low fluidity. Here, the considerably low fluidity refers to fluidity that prevents the material constituting the pressure-sensitive adhesive layer 3b from entering between the wires when the protective film 3 is provided on the metal wire layer 2. Examples of such so-called low-flowing elastic materials include low-flowing rubber-based elastic materials. Specifically, an acrylic pressure-sensitive adhesive mainly composed of a polyacrylic acid ester, a crosslinked silicone rubber (polyorganosiloxane), natural rubber, polyisobutylene and the like can be mentioned. Moreover, it is preferable that the material which comprises such an adhesive layer 3b has few low molecular weight components (volatile component). Additives such as tackifiers, oils, and glass transition temperature shift agents may be added to such rubber materials within the qualitative and quantitative ranges that do not impair the effects of the present invention. The pressure-sensitive adhesive layer 3b made of such a material is bonded to the metal wire layer 2 mainly by van der Waals force. Thereby, as above-mentioned, it becomes possible to stick and peel the protective film 3 many times with respect to the base material 1 which has the metal wire layer 2. FIG.

  When the protective film 3 having the pressure-sensitive adhesive layer 3b as described above is provided on the substrate 1 having the metal wire layer 2, the transmitted light intensity at the time of orthogonal Nicol with respect to linearly polarized light having a wavelength of 500 nm is It is preferable that it is 2 times or less of the case where no is provided. As a result, it is possible to prevent a practical performance degradation with respect to visible light having a shorter wavelength up to about 400 nm where the visibility is lowered. For example, in the space between the wires of the metal wire layer 2, a medium having a refractive index close to 1.0 such as air is present, so that the metal wire exhibits a high degree of polarization even for light having a short wavelength of about 500 nm The polarization performance of the layer 2 can be sufficiently exhibited. For this reason, the flowability of the pressure-sensitive adhesive layer 3b is made as low as possible so that the pressure-sensitive adhesive layer 3b does not enter the space between the wires in order to maintain a high degree of polarization with respect to light having a short wavelength of about 500 nm or less. is necessary. In particular, when the wire pitch is large, it is preferable to lower the fluidity of the pressure-sensitive adhesive layer 3b in order to prevent the pressure-sensitive adhesive layer 3b from easily entering the space between the wires. Moreover, since the wire of the metal wire layer 2 has a pitch of 150 nm or less, it can exhibit an excellent degree of polarization over a wide band in the visible light region. Furthermore, since the protective film 3 is provided, the metal wire layer 2 is not exposed and is protected by the protective film 3.

  The thickness of the pressure-sensitive adhesive layer 3b is such that the concavo-convex shape of the virtual surface passing through the top of the wire of the metal wire layer 2 (the surface concavo-convex shape of the macro polarizing plate not including the fine structure of the wire grid), the base substrate of the substrate 1 11 rigidity (thickness, elastic modulus), bonding force required between the metal wire layer 2 and the protective film 3, low fluid elastic material follows the top of the wire and comes into contact. Determine as appropriate. For example, when the virtual surface is flat or when the base substrate 11 is relatively thin so as to have a thickness of 10 μm or less, the thickness of the pressure-sensitive adhesive layer 3b is 1 μm to 10 μm. In the case where the thickness of the base substrate 11 is 10 μm or more, it is preferably 5 μm to 50 μm.

  The protective film substrate 3a is transparent and has sufficient rigidity to protect the wires of the metal wire layer 2. Examples of the material constituting the protective film substrate 3a include COP, PC, PS, and TAC. Further, considering that the protective film 3 is incorporated into a liquid crystal display device, it is preferable that the birefringence is small, and the phase difference is preferably 20 nm or less. On the other hand, the protective film 3 can be configured to double as a retardation film. In this case, the retardation of the protective film 3 is preferably 80 nm or more. Thus, when the protective film 3 also serves as a retardation film, the number of constituent members can be reduced and the liquid crystal display device or the like can be thinned.

Next, examples performed for clarifying the effects of the present invention will be described.
(Formation of grid-shaped convex part)
First, using the method described in Japanese Patent Application No. 2006-2100 of the present applicant, the pitch and height of the fine concavo-convex lattice on the surface are changed from the fine concavo-convex lattice having a pitch of 230 nm and the fine concavo-convex lattice height of 350 nm. A nickel stamper having a thickness of 140 nm / 162 nm, a thickness of 0.3 mm, a length of 300 mm, and a width of 180 mm was produced.

-Production of lattice-shaped convex transfer film using ultraviolet curable resin A COP film (Arton) with a thickness of 100 μm was irradiated with 100 mJ / cm ² of ultraviolet light having a central wavelength of 173 nm to produce a silane coupling agent (Shin-Etsu Chemical). Kogyo Co., Ltd., KBM-5103) A silane coupling agent solution consisting of 0.5 wt%, acetic acid 0.1 wt%, water 20 wt%, ethanol 89.7 wt% was spin-coated and dried. Thereafter, an ultraviolet curable resin (Toyo Gosei Kogyo Co., Ltd., PAK01) was applied by about 0.03 mm, and the nickel stamper was applied from the end to the nickel stamper having the fine concavo-convex grating with the 140 nm pitch with the coating surface down. The film was placed so that air did not enter between the films, and the ultraviolet curable resin was cured by irradiating with 1000 mJ / cm ^{2 of} ultraviolet rays from the PET film side using an ultraviolet lamp having a central wavelength of 365 nm. Then, the COP film was peeled from the nickel stamper to produce a lattice-shaped convex transfer film having a length of 300 mm and a width of 180 mm.

(Production of wire grid polarizer)
-Formation of dielectric layer using sputtering method An inorganic transparent dielectric material was applied to the obtained ultraviolet curable resin lattice-shaped convex transfer film using a sputtering method. In this example, Si ₃ N ₄ was used as the inorganic transparent dielectric, and Si ₃ N ₄ was deposited on the lattice-shaped convex transfer film produced by the above method. In this case, as a layer thickness comparison sample, a glass substrate having a smooth surface is inserted into the apparatus together with a lattice-shaped convex transfer film, Ar gas pressure is 0.70 Pa, sputtering power is 4 W / cm ² , and lamination speed is 0.20 nm / s. The film was formed so that the Si ₃ N ₄ lamination thickness on the smooth glass substrate was 7 nm.

-Metal vapor deposition using vacuum vapor deposition After laminating Si ₃ N ₄ on the grid-like convex transfer film, metal was deposited using electron beam vacuum vapor deposition (EB vapor deposition). In this example, aluminum (Al) was used as a metal, and aluminum was deposited at a vacuum degree of 2.5 × 10 ⁻³ Pa, a deposition rate of 4 nm / s, and at room temperature. In this case, as a layer thickness comparison sample, a glass substrate having a smooth surface was inserted into the apparatus together with a lattice-shaped convex transfer film, and vapor deposition was performed so that the aluminum deposition thickness on the smooth glass substrate was 200 nm.

・ Elimination of unnecessary metal by etching After depositing Al on the lattice-shaped convex transfer film, the film was washed in 0.1 wt% sodium hydroxide aqueous solution at room temperature under two conditions of 55 seconds and 80 seconds, and immediately The etching was stopped by washing with water. Thereafter, the film was dried to produce a lattice-shaped convex transfer film having a metal wire layer. The size of the lattice-shaped convex transfer film was 300 mm long and 180 mm wide. When the cross section of the lattice-shaped convex portion transfer film was observed with a field emission scanning electron microscope, the pitch of the lattice-shaped convex portions, the height of the formed aluminum, and the width were 140 nm / 162 nm / 63 nm, 140 nm / It was 130 nm / 55 nm.

(Preparation of protective film)
The PET base material protective film used in Examples 1 and 4 is a film (Fujiko Pian Co., Ltd., FIXFILM HG2) provided with a 25 μm thick silicone rubber adhesive layer on a 50 μm thick PET base material. After being immersed in hexane for 1 hour, it was dried in a hot air dryer at 80 ° C. for 3 hours to remove the low molecular weight eluate.

The COP base material protective film used in Examples 2 and 5 was irradiated with 100 mJ / cm ² of ultraviolet light having a center wavelength of 173 nm on a COP film having a thickness of 100 μm (manufactured by JSR Corporation, Arton), and a silane coupling agent (Shin-Etsu Chemical Co., Ltd.). Kogyo Co., Ltd., KBM-5103) A silane coupling agent solution consisting of 0.5% by weight, acetic acid 0.1% by weight, water 20% by weight and ethanol 89.7% by weight is spin-coated and dried, and polyorgano A solution consisting of 98% by weight of siloxane (manufactured by Shin-Etsu Chemical Co., Ltd., KNS-316) and 2% by weight of a catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., PL-50T) was applied by 25 μm with a gravure coater and heated at 150 ° C. for 3 minutes. After forming a pressure-sensitive adhesive layer on the protective film substrate by crosslinking the silicone rubber, the low molecular weight is similar to that of the PET substrate protective film. Prepared by removing the volume eluate.

  As a PET base material protective film used in Examples 3 and 6, a 59 μm thick film (RP301, manufactured by Nitto Denko Corporation) obtained by applying an acrylic adhesive having low fluidity to a PET film was used.

  The protective film was adhered to the lattice-shaped convex transfer film so that the pressure-sensitive adhesive layer of these protective films was opposed to the metal wire layer. Thereafter, the lattice-shaped convex transfer film with the protective film attached was left in a hot air dryer at 80 ° C. for 1 day, taken out of the hot air dryer, and returned to room temperature. Thus, the wire grid polarizing plate of the example was produced.

  As a PET base material protective film used in Reference Examples 1 and 2, a film having a thickness of 63 μm obtained by applying 25 μm of an acrylic adhesive having a high fluidity to a PET film having a thickness of 38 μm (manufactured by Nitto Denko Corporation, CS9621) Was used, and the protective film was closely adhered to the lattice-shaped convex transfer film so that the adhesive layer of the protective film was opposed to the metal wire layer. Thereafter, the lattice-shaped convex transfer film with the protective film attached was left in a hot air dryer at 80 ° C. for 1 day, taken out from the hot air dryer, and returned to room temperature. Thus, the wire grid polarizing plates of Reference Examples 1 and 2 were produced.

(Evaluation of polarization performance and shape by spectrophotometer)
About the obtained wire grid polarizing plate of an Example and a reference example, the transmitted light intensity at the time of the parallel Nicol with respect to linearly polarized light and the time of orthogonal Nicol was measured using the spectrophotometer. The measurement wavelength range was 400 nm to 780 nm as visible light, and the degree of polarization and light transmittance were calculated from the following equations. In addition, since the PET film was included in the protective film substrate, the light incident surface was set to the protective film side for the purpose of removing the influence of birefringence of the protective film substrate.
Polarization degree = [(Imax−Imin) / (Imax + Imin)] × 100 (%)
Light transmittance = [(Imax + Imin) / 2] × 100 (%)
Here, Imax is the transmitted light intensity at the time of parallel Nicols, and Imin is the transmitted light intensity at the time of crossed Nicols.

  The wire grid polarizing plate (Example 1) according to the present invention showed an excellent degree of polarization over almost the entire visible light region even with a protective film. This is presumably because in the wire grid polarizing plate of the present invention, the adhesive of the protective film hardly penetrates between the wires of the metal wire layer. On the other hand, the wire grid polarizing plate of Reference Example 1 has a remarkable decrease in the degree of polarization on the short wavelength side in the visible light region, and the transmitted light intensity at the time of crossed Nicols with respect to linearly polarized light having a wavelength of 500 nm is provided with a protective film. It was 2.8 times that in the case of no. This is considered to be because, in the wire grid polarizing plate of the reference example, the soft and highly fluid adhesive of the protective film has entered between the wires of the metal wire layer. As described above, the wire grid polarizer according to the present invention has a fine concavo-convex grating with a pitch of 150 nm or less, has no structural limitation, and exhibits an excellent degree of polarization over a wide band in the visible light region. I understood that.

  Here, the polarization degree at the wavelength of 500 nm, the light transmittance, and the transmitted light intensity ratio at the time of crossed Nicols in Examples 1 to 6 and Reference Examples 1 and 2 are shown in Tables 1 and 2, and Examples 1 to 3 and Reference Example 1 are shown. FIGS. 3 and 4 show the degree of polarization for light having a wavelength of 400 nm to 780 nm and the transmitted light intensity ratio at the time of crossed Nicols, respectively. The light transmittance of the examples is lower than the light transmittance of the wire grid polarizing plate without the protective film, mainly due to reflection by the surface of the protective film, and the protective film surface is subjected to antireflection treatment. By doing so, the light transmittance is improved.

  In the wire grid polarizing plate of the present invention, as shown in FIG. 2, a reflective layer 5 may be provided on the main surface of the base substrate 11 on the side opposite to the wire side. Moreover, you may attach the release paper 6 through the adhesive layer 4 on the protective film 3. FIG. With such a configuration, the release paper 6 can be peeled off and the wire grid polarizer can be attached to the device by the adhesive layer 4. In this case, a normal transparent adhesive material can be used as a material constituting the adhesive layer 4. In addition, examples of a device to which the wire grid polarizer is attached include a display device such as a liquid crystal display device.

  The present invention is not limited to the embodiment described above, and can be implemented with various modifications. For example, the dimensions, materials, and the like in the above-described embodiment are illustrative, and can be changed as appropriate. Moreover, the polarizing plate in the said embodiment does not need to be a plate-shaped member, and may be a sheet form and a film form as needed. Further, in the above embodiment, a case is described in which a grid-like convex transfer film obtained by metal vapor deposition after stretching a film having a grid-like convex portion is used. You may use the wire grid polarizer which has the lattice-shaped convex part of the narrow pitch obtained by the method of this. In addition, various modifications can be made without departing from the scope of the present invention.

It is a schematic sectional drawing which shows a part of wire grid polarizing plate which concerns on embodiment of this invention. It is a figure which shows the other example of the wire grid polarizing plate which concerns on embodiment of this invention. It is a figure which shows the polarization degree of the wire grid polarizing plate which concerns on embodiment of this invention, and the wire grid polarizing plate of a reference example. It is a figure which shows the transmitted light intensity ratio at the time of orthogonal Nicol with respect to the linearly polarized light of the wire grid polarizing plate which concerns on embodiment of this invention, and the wire grid polarizing plate of a reference example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 1a Lattice-like convex part 2 Metal wire layer 3 Protective film 3a Protective film base material 3b, 4 Adhesive layer 5 Reflective layer 6 Release paper 11 Base base material 12 UV curable resin layer

Claims (6)

Protection having a transparent base material having a grid-like convex part, a metal wire layer provided on a region of the base material including the grid-like convex part, and an adhesive layer in close contact with a tip part of the metal wire layer Film, and the base material has a pitch of 150 nm or less, and the adhesive force of the pressure-sensitive adhesive layer to the metal wire layer is 0.02 N / 25 mm to 1 N / 25 mm as a peel force in the direction of 180 degrees with respect to a smooth surface. , and the transmitted light intensity at orthogonal Nicol the pressure-sensitive adhesive layer for linearly polarized light of wavelength 500nm is that it is an elastic material having a 2-fold less to become such the fluidity of the case of not providing the protective film A wire grid polarizer characterized by. The elastic material, a wire grid polarizer according to claim 1, characterized in that the crosslinked silicone rubber or acrylic adhesive. The wire grid polarizer according to claim 1 or 2 , wherein the protective film has a retardation of 20 nm or less. The wire grid polarizing plate according to any one of claims 1 to 3 , wherein the protective film has a retardation of 80 nm or more, and the protective film also serves as a retardation film. The wire grid polarizer according to any one of claims 1 to 4 , wherein the protective film is selected from the group consisting of COP, PC, PS, TAC, and PET. The wire grid polarizing plate according to any one of claims 1 to 5, wherein the pressure-sensitive adhesive layer has a thickness of 1 µm to 10 µm.

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