JP2014085516A - Wire grid polarizing plate and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire grid polarizing plate having high persistence of the resistance to moist heat, and provide a method of manufacturing the polarizing plate.SOLUTION: The wire grid polarizing plate (10) includes: a base material (101); metal wire layers (102) disposed at a certain interval on a surface of the base material (101) and on one-side surfaces of base material projections (101a) extending in a certain direction; a first coating layer (103) that covers the surface of the base material (101) including the metal wire layers (102) and contains at least one of an inorganic material and metallic oxide material; and a second coating layer (104) that covers the surface of the first coating layer (103) and is made of a fluorine-containing composition.

Description

  The present invention relates to a wire grid polarizing plate excellent in wet heat resistance and a method for producing the same.

  With the recent development of photolithography technology, it has become possible to form a fine structure pattern having a pitch at the wavelength level of light. Such a member or product having a pattern with a very small pitch is useful in a wide range of applications not only in the semiconductor field but also in the optical field.

  For example, a wire grid polarizing plate in which conductor wires made of metal or the like are arranged in a lattice pattern at a specific pitch has a pitch that is considerably smaller than the incident light (for example, less than a half). As a polarizer that creates a single polarized light, it reflects almost all the light of the electric field vector component that oscillates parallel to the conductor line and almost transmits the light of the electric field vector component perpendicular to the electric conductor line. Can be used. Since the wire grid polarizer can reflect and reuse light that does not transmit, it is also desirable from the viewpoint of effective use of light.

  However, the wire grid polarizer has a problem that due to its structure, it tends to cause oxidative degradation due to the reaction between the metal surface and moisture in the air. In order to prevent performance degradation due to this oxidative deterioration, a method of coating a metal wire grid surface with a resin is known (Patent Document 1).

  However, the method disclosed in Patent Document 1 has a problem in that when the substrate is a resin, the substrate absorbs water and warps in order to perform underwater treatment at a high temperature. This deteriorates the specularity of the wire grid polarizing plate, and there is a problem that it is difficult to adapt to an application using reflected light.

  The inventors of the present application reported a highly durable wire grid polarizing plate in Patent Document 2 in the past for this problem. Patent Document 2 shows that the metal wire surface is coated with a fluorine-based silane coupling agent or the like, so that the heat and moisture resistance can be improved and the polarizer can be produced without curling.

Japanese Patent No. 4411202 JP 2010-210829 A

  However, in the method described in Patent Document 2, a certain improvement in moisture and heat resistance can be obtained. However, in applications that are installed in in-vehicle applications, for example, higher moisture and heat resistance reliability is required, and the durability of moisture and heat resistance is maintained. It is an important issue to improve.

  An object of this invention is to provide the wire grid polarizing plate excellent in the sustainability of heat-and-moisture resistance, and its manufacturing method.

  As a result of intensive studies on the cause of oxidative deterioration of the metal wire layer, the inventors of the present application have found that the fixing property of the fluorine-based silane coupling agent to the metal wire surface is insufficient, and that the fluorine-based silane coupling agent is a metal wire. Since the oxide layer on the surface is selectively coated, attention was paid to the fact that it is affected by water absorption from the substrate surface.

  In the present invention, a fluorine-based silane coupling agent is provided by newly providing a coating layer made of at least one of an inorganic material and a metal oxide material between the metal wire layer and the fluorine-based coating layer. It has been found that the coating area and the fixability of the film are improved, and the heat and humidity resistance is dramatically improved under high temperature, high humidity and hot water environment. Based on this finding, the present inventors have made the present invention. That is, the present invention is as follows.

  The wire grid polarizing plate of the present invention comprises a base material, a metal wire layer extending in a constant direction at a constant interval on the surface of the base material, an inorganic material that coats at least the surface of the metal wire layer, and A first coating layer containing at least one of metal oxide materials, and a second coating layer made of a fluorine-containing composition that coats at least the surface of the first coating layer.

  With this configuration, peeling of the second coating layer can be reduced, and resistance to oxidative degradation caused by direct water molecules on the metal wire layer can be obtained.

  Moreover, the wire grid polarizing plate of this invention WHEREIN: It is preferable that the surface area of the said 1st coating layer is larger than the surface area of the said metal wire layer.

  Moreover, the wire grid polarizing plate of this invention WHEREIN: It is preferable that a said 1st coating layer coats the said metal wire layer and the boundary part of the said metal wire and the said base material simultaneously.

  With these configurations, in addition to reducing the peeling of the second coating layer, it is possible to reduce oxidative deterioration of the metal wire layer due to water content from the substrate surface in contact with the metal wire layer.

  In the wire grid polarizer of the present invention, the second coating layer is at least one cup selected from the group consisting of a fluorinated silane coupling agent, a fluorinated aluminate coupling agent, and a fluorinated titanate coupling agent. It is preferable that a ring agent is included.

  Further, in the wire grid polarizer of the present invention, the metal wire layer is in contact with a side surface on one side of a base material convex portion having a lattice-like uneven shape extending in a specific direction on the surface of the base material, It is preferable to be provided so as to extend upward from the top of the base material convex portion.

  The method for producing a wire grid polarizing plate of the present invention includes a base material and a metal wire layer extending in a constant direction at a constant interval on the surface of the base material. Forming a first coating layer containing at least one of the metal oxide materials by a sputtering method, and forming a second coating layer made of a fluorine-containing composition on the surface of the first coating layer surface by a wet method. It is characterized by comprising.

  With this configuration, the first coating layer can be formed thinly and uniformly with excellent adhesion by sputtering on the surface of the base material and the metal wire layer, and the first coating layer is wet on the surface of the first coating layer. The second coating layer can be formed easily and reliably by the method. Moreover, since the obtained 1st coating layer has coat | covered the said metal wire layer and the boundary part of the said metal wire and the said base material simultaneously, in addition to the peeling reduction of a 2nd coating layer, metal Oxidative deterioration of the metal wire layer due to water content from the base material surface in contact with the wire layer can be reduced.

  According to the present invention, waterproofing and moisture resistance are imparted to the wire grid polarizing plate provided with the metal wire layer by the second coating layer, and the second coating layer is prevented from being peeled off by the first coating layer. It is possible to improve the durability and durability of moisture resistance, and to provide a wire grid polarizer with little change in polarization transmittance even when exposed to high temperature and high humidity for a long time.

It is an upper surface schematic diagram which shows the wire grid polarizing plate which concerns on this Embodiment. It is a cross-sectional schematic diagram which shows the wire grid polarizing plate which concerns on this Embodiment. It is an expanded sectional schematic diagram which shows the wire grid polarizing plate which concerns on this Embodiment. It is an expanded sectional schematic diagram which shows the other example of the wire grid polarizing plate which concerns on this Embodiment. It is an expanded sectional schematic diagram which shows the other example of the wire grid polarizing plate which concerns on this Embodiment.

  Hereinafter, an embodiment of the present invention (hereinafter abbreviated as “embodiment”) will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

  FIG. 1 is a schematic top view showing a wire grid polarizer according to the present embodiment. 2 is a schematic cross-sectional view corresponding to a cross section between a and b in FIG. The wire grid polarizing plate 10 shown in FIG. 1 has a grid-like uneven shape in which a plurality of convex portions 11 extending in a specific direction are arranged in parallel at a predetermined pitch on the surface.

  As shown in FIG. 2, the wire grid polarizing plate 10 includes a base material 101 having a grid-like uneven shape extending in a specific direction, and one direction of a base material convex portion 101 a constituting the grid-like uneven shape of the base material 101. A metal wire layer 102 that is in contact with the side surface on the side and is provided so as to extend upward from the top of the base material convex portion 101a.

  Further, as shown in FIG. 2, the wire grid polarizer 10 includes a first coating layer 103 that covers the surfaces of the base material 101 and the metal wire layer 102, and a second coating layer that covers the surface of the first coating layer 10. 104.

  FIG. 3 is an enlarged schematic cross-sectional view showing the wire grid polarizer according to the present embodiment. As shown in FIG. 3, the first coating layer 103 covers the entire surface of the substrate 101 including the metal wire layer 102. For this reason, it is larger than the surface area of the metal wire layer 102. Further, the first coating layer 103 coats the boundary between the metal wire layer 102 and the substrate 101 at the same time as coating the metal wire layer 102.

  Although the case where the first coating layer 103 covers the entire surface of the base material 101 including the metal wire layer 102 has been described with reference to FIG. 3, the present invention is not limited to this. For example, as shown in FIG. 4, a first coating layer 103 is provided so as to selectively cover only the surface of the metal wire layer 102, and the entire surface of the substrate 101 including the first coating layer 103 is covered with the second coating layer 103. 104 may be covered. Further, as shown in FIG. 5, when the first coating layer 103 is provided, the metal wire layer 102 provided on one side surface of an arbitrary base material projection 101a of the base material 101, and the base material adjacent thereto The effect of the present invention can be obtained even when the first coating layer 103 is cross-linked with the convex portion 101a and the gap portion 110 is generated between the first coating layer 103 and the substrate 101. it can.

  Hereinafter, each part structure of the wire grid polarizing plate 10 which concerns on this Embodiment is demonstrated in detail.

(1) Base material 101
The substrate 101 only needs to be substantially transparent in the target wavelength region. For example, an inorganic material such as glass or a resin material can be used for the base material 101. In particular, the base material 101 made of a resin material is preferable in that it can have flexibility and a roll process is possible. Examples of the resin that can be used for the substrate 101 include polymethyl methacrylate resin, polycarbonate resin, polystyrene resin, cycloolefin resin (COP), crosslinked polyethylene resin, polyvinyl chloride resin, polyarylate resin, polyphenylene ether resin, Amorphous thermoplastic resin such as modified polyphenylene ether resin, polyetherimide resin, polyether sulfone resin, polysulfone resin, polyether ketone resin, polyethylene terephthalate (PET) resin, polyethylene naphthalate resin, polyethylene resin, polypropylene resin, Crystalline thermoplastic resins such as polybutylene terephthalate resin, aromatic polyester resin, polyacetal resin, and polyamide resin, and ultraviolet rays such as acrylic, epoxy, and urethane types UV) curable resin or thermosetting resin. Further, the base material 101 may be configured by combining an ultraviolet curable resin or a thermosetting resin with an inorganic base material such as glass, the thermoplastic resin or the triacetate resin, or using them alone.

(2) Metal wire layer 102
Examples of the metal that can be suitably used for the metal wire layer 102 include aluminum, silver, copper, platinum, gold, and alloys containing these metals as main components. Among these, aluminum or silver is particularly preferable since it has a small absorption loss in the visible region. Further, the surface of the metal wire layer 102 may be naturally oxidized.

(3) Cross-sectional shape of base material Although there is no restriction | limiting in the cross-sectional shape of the base material 101 in the surface perpendicular | vertical to the extension direction of the metal wire layer 102, from a viewpoint of transmission polarization performance, a cross-sectional shape must be a grid | lattice-like uneven shape. preferable. Examples of the lattice-shaped uneven shape include a trapezoidal shape, a rectangular shape, a rectangular shape, a prism shape, and a semicircular sine wave shape. 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. From the viewpoint of transmittance, the cross-sectional shape of the substrate is preferably rectangular or sinusoidal.

  In the case of using the base material 101 having the lattice-shaped uneven structure, the manufacturing method is not particularly limited. For example, it can be manufactured by a stepper apparatus using a reticle mask pattern, which is one of semiconductor lithography methods. The resist surface uniformly formed on the silicon wafer is exposed through a reticle mask, and the resist surface is subjected to pattern exposure by a step-and-repeat method. After development, a line-and-space resist pattern with a pitch of 150 nm or less is formed. Next, using this resist pattern as a mask pattern, a pattern is formed on a silicon wafer by dry etching. As a result, a substantially rectangular fine concavo-convex lattice pattern with a pitch of 150 nm or less is obtained. The produced patterned silicon plate is transferred with a resin, and a metal stamper having a fine concavo-convex lattice is produced using an electroplating method or the like. By using this metal stamper to transfer and form the fine concavo-convex lattice on the surface of the resin base material, it is possible to obtain a resin base material having lattice-like convex portions with a pitch of 150 nm or less.

  As another production example, a method described in Japanese Patent No. 4147247 filed separately by the applicant can be cited. According to Japanese Patent No. 4147247, a concavo-convex grid is thermally transferred to a thermoplastic resin by using a metal stamper having a concavo-convex grid formed by a grid-shaped convex part having a pitch of 230 nm to 250 nm manufactured using an interference exposure method. The free end uniaxial stretching process with a stretching ratio of 4 to 6 times is performed in a direction parallel to the longitudinal direction of the lattice. As a result, the pitch of the concavo-convex grid transferred to the thermoplastic resin is reduced, and a resin base material (stretched) having a fine concavo-convex grid with a pitch of 120 nm or less is obtained. Then, the metal stamper which has a fine uneven | corrugated lattice is produced from the resin base material (drawn | stretched) which has the obtained fine uneven | corrugated lattice using the electrolytic plating method. By using this metal stamper to transfer and form the fine concavo-convex lattice on the surface of the resin base material, it becomes possible to obtain a resin base material having lattice-like convex portions with a pitch of 120 nm or less.

(4) Pitch width In general, wire grid polarizers can exhibit polarization characteristics in a wider band as the pitch width of the metal wire becomes smaller, but when considering polarization characteristics only in the near infrared to infrared region, the pitch May be about 300 nm or less, and the pitch may be about 150 nm or less when the polarization characteristics in the short wavelength region of about 400 nm or less are not important. In the case of obtaining sufficient polarization characteristics over the entire visible light region, the pitch is preferably approximately 120 nm or less, and more preferably 80 nm to 120 nm.

  Further, in order to form the first coating layer 103 following the concavo-convex structure, the pitch is preferably 80 nm or more, and in order to enhance the water repellent effect after the second coating layer 104 is laminated, the pitch interval is small. It is preferable that it is 150 nm or less.

(5) Manufacturing Method of Metal Wire Layer 102 There is no particular limitation on the manufacturing method of the metal wire layer 102. Examples of the method include mask patterning by electron beam lithography or interference exposure and dry etching, and oblique vapor deposition. The oblique vapor deposition method is preferred from the viewpoint of productivity. Further, from the viewpoint of optical characteristics, it is preferable to remove unnecessary metal by etching. The etching method is not particularly limited as long as it does not adversely affect the substrate 101 and the dielectric layer (not shown) and can selectively remove the metal portion, but is immersed in an alkaline aqueous solution from the viewpoint of productivity. The method is preferred.

(6) First coating layer 103
The first coating layer 103 is preferable in that it includes at least one selected from the group consisting of an inorganic material or a metal oxide, and functions as a barrier function for protecting the surface of the metal wire layer 102 from water molecules and gas molecules. The first coating layer 103 also functions as a layer necessary for stably fixing the second coating layer 104 and maintaining the water molecule elimination effect by the second coating layer 104.

  The inorganic material here is not particularly limited in composition, and examples thereof include silicon nitride, silicon oxide, silicon carbide, and diamond-like carbon. The metal oxide is not particularly limited, and examples thereof include titanium oxide and indium tin oxide (ITO). In any case, the kind of inorganic material or metal oxide is not particularly limited as long as it can function as a barrier function for protecting the surface of the metal wire layer 103 from water molecules and gas molecules.

  In order to prevent a decrease in transmittance before and after the first coating layer 103 is laminated, it is preferable that the material has substantially no absorption at least in the polarization transmission wavelength region to be used.

  The first coating layer 103 may be composed of a single layer structure having a single composition, a multilayer structure having a plurality of layers, or a layer in which a plurality of compositions are mixed.

  The first coating layer 103 is obtained by laminating at least the surface of the metal wire layer 102. More preferably, not only the surface of the metal wire layer 102 but also the boundary portion between the metal wire layer 102 and the base material 101 is covered at the same time, so that water content from the base material surface at the boundary portion can be prevented. .

  More preferably, the first wire layer 103 covers the entire surface of the substrate 101 including the metal wire layer 102, that is, the metal wire surface side of the wire grid polarizer 10, thereby absorbing water from the surface of the substrate 101. It is possible to prevent oxidative deterioration of the metal wire layer 102 due to water molecules from the inner surface of the substrate. As already described with reference to FIG. 5, the first coating layer 103 may be cross-linked so that a part of the gap 110 remains in the recesses 101 b between the projections 101 a.

  Most preferably, as shown in FIG. 3, the entire surface of the base material 101 of the wire grid polarizer 10 is covered with the first coating layer 103. In this case, water absorption from the outside can be minimized. .

  The thickness of the first coating layer 103 is preferably 40 nm or less in order to prevent a decrease in transmittance and polarization performance before and after coating, and 30 nm or less in order to prevent generation of cracks due to bending after film formation. It is preferable that the polarization characteristics in the infrared / visible wavelength range can be maintained at 25 nm or less, the polarization characteristics in the infrared / visible / ultraviolet wavelength range can be maintained by being 15 nm or less, A first coating layer 103 that follows the pattern shape can be provided. On the other hand, when the thickness is 2 nm or more, the fixability of the first coating layer 103 is improved. The variation in thickness of the first coating layer 103 is not particularly limited, but there is no particular problem as long as the thickness is within the above range.

  The surface of the first coating layer 103 may be in a roughened state with a nanometer size. As a result, the surface area of the first coating layer 103 can be increased and the coverage area of the second coating layer 104 laminated on the first coating layer 103 can be increased, so that the surface can be protected with more components and the heat and moisture resistance can be improved. Sustainability is obtained.

(7) Second coating layer 104
The second coating layer 104 is a layer necessary for preventing the adhesion of water molecules and organic molecules, and is important from the viewpoint of waterproofness, moist heat resistance, and antifouling properties. In particular, it contains fluorine containing low surface energy. It preferably consists of a composition. Moreover, in order to fix it stably to the 1st coating layer 103, it is preferable to have a reactive group at the terminal of molecular structure.

  Examples of fluorine-containing compositions are not particularly limited as long as they contain fluorine atoms, but fluorine-containing organic molecules containing perfluoroether groups, perfluoroalkyl groups, etc. The density is high and the surface energy is sufficiently small, which is effective as a water repellent effect.

  The second coating layer 104 is not particularly limited as long as it can achieve thermodynamically stable fixation with the first coating layer 103, but it is preferable to chemically fix the second coating layer 104 to the surface of the first coating layer 103. For example, a hydrolyzable silane coupling group or the like chemically reacts and is stably immobilized when a hydroxyl group is localized in the outermost surface layer of the first coating layer 103. Moreover, by containing a plurality of reactive groups in one molecule, not only the surface of the first coating layer 103 but also the inside of the second coating layer 104 reacts randomly in the three-dimensional direction to form a cross-link. A stronger second coating layer 104 can be formed.

  In addition, in order to prevent a decrease in transmittance before and after the second coating layer 104 is laminated, it is preferable that the material has substantially no absorption in at least the polarized light transmission wavelength region to be used.

  The thinner the second coating layer 104 is, the smaller the thickness is, because the optical characteristics of the wire grid polarizer 10 are not affected. In the case of monomolecular orientation, the thickness of the second coating layer 104 is 50 nm or less as an index of the thickness of the monomolecular film or as an index of the thickness of the second coating layer 104 including physical adsorption. The transmittance difference before and after formation can be suppressed to 1% or less, and more preferably 20 nm or less. Further, when the thickness is 3 nm or more, the effect of water repellency can be exhibited, and when the thickness is 6 nm or more, the durability to moisture and heat resistance is improved.

  The second coating layer 104 is made of a fluorine-based silane coupling agent or a fluorine-based aluminate coupling from the viewpoint that even a fine structure with a pitch of 150 nm or less can be uniformly coated with a thickness of 20 nm or less and the transmittance is extremely low. It is preferable that it is at least 1 type of coupling agent chosen from the group which consists of an agent or a fluorine-type titanate coupling agent.

  In particular, in order to strengthen the adhesion with the first coating layer 103, the second coating layer 104 may be formed by dehydration condensation between the hydroxyl group of the coupling agent and the hydroxyl group on the surface of the metal wire layer 102. Preferably, the fluorine compound is a fluorine-based silane coupling agent, fluorine-based aluminate coupling agent, or fluorine having a perfluoropolyether structure from the viewpoint that the film thickness can be made more uniform and thinner. A titanate coupling agent is preferred.

In particular, a fluorine-based compound having a perfluoropolyether structure represented by the following formula (I) is preferable because a uniform film thickness of 10 nm or less and particularly strong adhesion with aluminum can be achieved.
_{C n F 2n + 1 -Z-} Y-X- (OC 3 F 6) a- (OC 2 F 4) b- (OCF 2) c-O-X-Y-Z-M (OH) α (OR) β (P) _γ (Q) _m-α-β-γ (I)
(Wherein, a, b and c each independently represent 0 or an integer of 1 or more, the sum of a, b and c is at least 1 and enclosed in parentheses with a, b and c attached thereto) In addition, the order of existence of each repeating unit is arbitrary in the formula.
X is a formula _{:-( O) d- (CF 2)} e- (CH 2) f- ( wherein, d, e and f each independently represent 0 or an integer of 1 or more, e and f Is the sum of at least 1, and the order of presence of each of the repeating units enclosed in parentheses with d, e and f is arbitrary in the formula, but O is not continuous. .
Y represents a divalent polar group or a single bond.
Z represents a group represented by the formula:-(CH ₂ ) g- (where g represents 0 or an integer of 1 or more).
M represents a silicon atom, a titanium atom or an aluminum atom.
P represents a hydrolyzable polar group.
Q represents hydrogen or a hydrocarbon group.
R represents a hydrocarbon group.
m represents an integer of valence-1 of M.
α represents an integer of 1 to m,
β and γ represent 0 or an integer of 1 to m,
α + β + γ represents an integer of 1 to m.
n is an integer of 1 or more.
—OC ₃ F ₆ — represents —OCF ₂ CF ₂ CF ₂ — or OCF (CF ₃ ) CF ₂ —, —OC ₂ F ₄ — represents —OCF ₂ CF ₂ — or —OCF (CF ₃ ) —. Represent. )

  In the above formula (I), among the silicon atom, titanium atom, and aluminum atom, the structure using a silicon atom for M is at least one selected from the group consisting of silicon nitride, silicon oxide, silicon carbide, and titanium oxide. It is preferable because it suppresses a decrease in transmittance when coated on one coating layer 103 and is excellent in adhesion.

(8) Manufacturing Method of First Coating Layer 103 A physical vapor deposition method such as a vacuum vapor deposition method, a sputtering method, or an ion plating method can be suitably used for the surface of the wire grid polarizing plate 10. In particular, it is a method capable of forming a thin and uniform film, in which physical adhesion to the surface of the metal wire layer 102 and the surface of the substrate 101 can be obtained, and film formation that easily follows the nano uneven shape. As the method, a sputtering method is more preferable.

(9) Manufacturing method of the 2nd coating layer 104 With respect to the surface of the 1st coating layer 103 laminated | stacked on the surface of the wire grid polarizing plate 10, in addition to dry methods, such as a vacuum evaporation method and a sputtering method, vapor diffusion method and liquid The method of laminating | stacking the 2nd coating layer 104 with wet methods, such as a dripping method and a liquid immersion method, is mentioned. In particular, when the second coating layer 104 is made of an organic molecule, a droplet dropping method or a liquid immersion method is more preferable as a method for easily and reliably forming a film.

  As an example of manufacturing the droplet dropping method or the liquid immersion method, a method of manufacturing the second coating layer 104 using a fluorine-based coupling agent solution will be described.

Example of drop-drop method:
Fluorine coupling in which the above-mentioned fluorinated coupling agent is dissolved in a solvent in such an amount that the entire surface of the wire grid polarizing plate (base material 101 and metal wire layer 102) on which the first coating layer 103 is laminated is spread. Add the solution dropwise. Thereafter, the surface of the coupling agent or between the coupling agent and the first coating layer 103 over 20 seconds RH, 98% RH or less, 10 ° C. or more, and 80 ° C. or less over several seconds to 12 hours. And react. That is, the hydrolysis and dehydration condensation reaction of the coupling agent is accelerated, the solid-liquid reaction between the first coating layer 103 and the fluorine-based coupling agent solution and the reaction between the coupling agents proceed, and the second coating layer 104 The film forming stability can be obtained. It is preferable to adjust the humidity, temperature, and time according to the required degree of heat resistance. Next, an excess amount of the fluorinated coupling agent adhering to the surface is removed using a fluorinated solvent. Thereby, the optical characteristic difference before and after lamination | stacking of the 2nd coating layer 104 can be made small. Then, the wire grid polarizing plate 10 which concerns on this Embodiment can be obtained by fully drying the surface of a wire grid polarizing plate with an air blow.

  Similarly, another method for producing the second coating layer 104 using the fluorine-based coupling agent solution will be described.

Examples of liquid immersion methods:
The wire grid polarizing plate (base material 101 and metal wire layer 102) on which the first coating layer 103 is laminated is immersed in the fluorine-based coupling agent solution, taken out from the solution, dried on the solvent, and then excessively on the wire grid polarizing plate. In order to remove the fluorine-based coupling agent deposited on the substrate, it is immersed in a fluorine-based solvent. Furthermore, drying is preferably performed in order to promote dehydration condensation between the hydroxyl group on the surface of the first coating layer 103 and the hydroxyl group of the fluorine-based coupling agent. Drying is preferably performed at 10 ° C. or more, 60 ° C. or less, 20% RH or more, 98% RH or less, 10 seconds or more and 1200 seconds or less, from the viewpoint of ensuring a uniform film thickness, More preferably, the drying is performed at 40 ° C. or less, 30% RH or more, 90% RH or less, and the drying time is 30 seconds or more and 600 seconds or less.

  By placing the wire grid polarizing plate on which the coating film of the fluorine-based coupling agent is formed at a higher temperature as described above, the dehydration condensation between the hydroxyl group of the first coating layer 103 and the hydroxyl group of the fluorine-based coupling agent is further accelerated. As a result, the bond between the first coating layer 103 and the fluorine-based coupling agent becomes stronger. Hereinafter, this process is called baking. Specifically, it is preferable to bake at 60 ° C. or higher and 150 ° C. or lower, more preferably 80 ° C. or higher and 120 ° C. or lower for 1 minute or longer and 60 minutes or shorter, more preferably 5 minutes or longer and 30 minutes or shorter. A second coating layer 104 is obtained.

  The fluorine-based coupling agent used for forming the second coating layer 104 is at least one coupling selected from the group consisting of a fluorine-based silane coupling agent, a fluorine-based aluminate coupling agent, or a fluorine-based titanate coupling agent. If it is an agent, the suitable 2nd coating layer 104 can be formed in the process similar to the said process.

(10) Dielectric Layer In order to improve the adhesion between the material constituting the base material 101 and the metal wire layer 102 in the present embodiment, a dielectric material having a high adhesion between them is used as a dielectric layer ( (Not shown). When the adhesion between the substrate 101 and the metal wire layer 102 is high, peeling of the metal wire layer 102 during the durability test can be prevented, and a decrease in the degree of polarization can be suppressed.

  Examples of dielectric materials that can be suitably used include, for example, silicon (Si) oxides, nitrides, halides, carbides, or composites thereof (dielectrics are mixed with other elements, simple substances, or compounds). Dielectric), aluminum (Al), chromium (Cr), yttrium (Y), zirconia (Zr), tantalum (Ta), titanium (Ti), barium (Ba), indium (In), tin (Sn), Zinc (Zn), magnesium (Mg), calcium (Ca), cerium (Ce), copper (Cu) and other metal oxides, nitrides, halides, carbides alone or a composite thereof can be used. . The dielectric material is preferably substantially transparent in a wavelength region where transmission polarization performance is to be obtained.

  There are no particular limitations on the method of laminating the dielectric material, and physical vapor deposition methods such as vacuum vapor deposition, sputtering, and ion plating can be suitably used.

(11) Optical performance In order not to impair the transmission performance of the wire grid polarizer 10, the visibility corrected transmission before and after the first coating layer 103 and the second coating layer 104 are formed on the surface of the metal wire layer 102. The difference in the rate T (transmittance difference ΔT) is preferably 1.0% or less. Furthermore, since it is substantially impossible to identify optical characteristics by human visual recognition, the transmittance difference ΔT is preferably 0.5% or less, and more preferably 0.25% or less.

  In order not to impair the polarization performance of the wire grid polarizing plate 10, the difference in the visibility correction polarization degree P before and after the formation of the first coating layer 103 and the second coating layer 104 on the surface of the metal wire layer 102 ( The polarization difference ΔP) is preferably 0.5% or less. Further, since it is substantially impossible to identify optical characteristics by human visual recognition, the polarization difference ΔP is preferably 0.2% or less, and more preferably 0.1% or less.

  The visibility corrected transmittance T and the visibility corrected polarization degree P are obtained by weighting the transmittance and the polarization degree at each wavelength by a standard relative visibility determined by the International Commission on Illumination. Specifically, it is represented by the following formulas (II) and (III).

Here, λ represents a wavelength, and T ^′ (λ) and P ^′ (λ) represent transmittance and polarization degree at each wavelength λ, respectively, and are represented by the following equations.
T ^′ (λ) = [(Imax + Imin) / 2] × 100%
P ^′ (λ) = [(Imax−Imin) / (Imax + Imin)] × 100%
(Imax is parallel Nicol for linearly polarized light at each wavelength λ, and Imin is transmitted light intensity in a direct Nicol state at each wavelength)

Φ (λ) represents the standard relative luminous sensitivity at each wavelength λ, λ ₁ is 380 nm, and λ ₂ is 780 nm.

Examples performed to confirm the effects of the present invention will be described below.
Example 1
<Preparation of a lattice-shaped uneven transfer film using an ultraviolet curable resin>
A Ni mold (hereinafter referred to as mold A) was used for the production of the lattice-shaped uneven shape transfer film. The mold A had a grid-like concavo-convex shape with a pitch width of 145 nm, and the concavo-convex shape in a cross section perpendicular to the extending direction of the grid was a substantially rectangular shape. An acrylic UV curable resin (refractive index of 1.52) is applied to a triacetyl cellulose resin (hereinafter abbreviated as TAC) film (TD80UL-H manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm, and the coated surface is placed downward. It put so that air might not enter between type A and a TAC film. Ultraviolet rays were irradiated from the TAC film side at 1000 mJ / cm ² using an ultraviolet lamp, and the grid-like uneven shape of the mold A was transferred. The TAC film was peeled from the mold to produce a film having a 300 mm long and 200 mm wide grid-like uneven shape transferred. Hereinafter, this is referred to as transfer film A.

<Production of wire grid polarizer>
Formation of Dielectric Layer Using Sputtering Method Next, silicon dioxide was formed as a dielectric layer on the lattice-shaped uneven shape transfer surface of the transfer film A by a sputtering method. The sputtering apparatus conditions were as follows: Ar gas pressure 0.2 Pa, sputtering power 770 W / cm ² , coating speed 0.1 nm / s, and the dielectric thickness on the transfer film A was 3 nm in terms of a flat film.

-Metal deposition using vacuum deposition method Next, aluminum (Al) was deposited by vacuum deposition on the lattice-shaped concavo-convex shape transfer surface of the transfer film A on which the dielectric layer was formed, whereby a polarizing film A was obtained. The deposition conditions for Al were normal temperature, a degree of vacuum of 2.0 × 10 ⁻³ Pa, and a deposition rate of 40 nm / s. In order to measure the thickness of Al, a glass substrate having a smooth surface was inserted into the apparatus simultaneously with the transfer film A, and the Al thickness on the smooth glass substrate was defined as the Al average thickness. In the plane perpendicular to the longitudinal direction of the lattice, the angle formed by the normal of the substrate surface and the deposition source is defined as the deposition angle θ. I let you.

  The average thickness here refers to the thickness of the deposit when it is assumed that the substance is deposited on the smooth glass substrate from the direction perpendicular to the glass surface, and is used as a measure of the deposition amount.

-Adjustment of polarization characteristics by removing unnecessary Al Next, the polarizing film A was immersed in a 0.1 wt% sodium hydroxide aqueous solution at room temperature for a predetermined time. Immediately after that, the film was washed with water and dried. The alkaline aqueous solution immersion time of the polarizing film A was set to a time when the polarization degree with respect to light having a wavelength of 550 nm of the treated polarizing film A was 99.9% or more and the light transmittance was 40% or more. Table 1 below shows the visibility correction transmittance T and the visibility correction polarization degree P of the polarizing film A after the alkaline aqueous solution immersion treatment. The measurement of the visibility corrected transmittance T and the visibility corrected polarization degree P was performed using a polarizing film evaluation apparatus V7000 manufactured by JASCO Corporation under the conditions of 23 ° C. and 65% RH. Hereinafter, the visibility correction transmittance T and the visibility correction polarization degree P were all measured under the above conditions.

-Preparation of the 1st coating layer 1 using sputtering method Next, the silicon oxide was formed into a film as the 1st coating layer 1 with the sputtering method on the surface of the polarizing film A optically adjusted. As the sputtering apparatus, SH-450 manufactured by ULVAC was used. The sputtering conditions were RF sputtering (power 770 W), Ar flow rate 10 sccm, film formation time 36 seconds, and film formation was performed so that the first coating layer 1 on the polarizing film A was 3 nm in terms of a flat film.

<Formation of the second coating layer 2 with a fluorine-based silane coupling agent>
Next, a fluorine-based silane coupling agent solution (HD-1101) manufactured by Harves Co., Ltd. was dropped onto the aluminum surface side of the polarizing film A on which the first coating layer 1 was laminated so that the aluminum surface side spreads over the entire surface. In order to accelerate the reaction, it was allowed to stand for 3 hours under conditions of 60 ° C. and 90% RH, and then for 6 hours under conditions of 23 ° C. and 60% RH. Subsequently, for the purpose of washing and removing the fluorine-based silane coupling agent excessively adhered on the polarizing film A, a fluorine solvent (HD-ZV) manufactured by Harves Co., Ltd. is appropriately poured, and then the fluorine solvent is dried by air blowing. Removed. The polarizing film A on which the first coating layer 1 and the second coating layer 2 were laminated was referred to as a post-coating polarizing film A, which was Example 1.

(Comparative Example 1)
After polarizing film A was etched to adjust the polarization characteristics, polarizing film B was obtained by laminating only second coating layer 2 on the aluminum surface side. The method for laminating the second coating layer 2 was made in the same manner as the method described in Example 1.

(Comparative Examples 2, 3, 4)
After adjusting the polarization characteristics by etching the polarizing film A, the polarizing film C is formed by laminating only the first coating layer 1 on the aluminum surface side and forming the film so as to be 3 nm in terms of a flat film of the first coating layer 1. A polarizing film D was formed to have a thickness of 30 nm in terms of a flat film, and a polarizing film E was formed to have a thickness of 40 nm in terms of a flat film. The method of laminating the first coating layer 1 was the same as the method described in Example 1, and the film thickness was adjusted by adjusting the film deposition integration time.

<Evaluation of optical properties 1: Evaluation of optical properties before and after the formation of the coating layer>
The transmittance T and the degree of polarization P in the visible light region (380 nm to 780 nm) before and after the formation of the coating layer of Example 1 and Comparative Examples 1 to 4 were measured with a polarizing film evaluation device V7000 manufactured by JASCO Corporation. The values of the visibility correction transmittance T and the visibility correction polarization degree P of each polarizing film before and after the formation of the coating layer are shown in Table 1 below. In either case, the transmittance and polarization degree before and after the coating were not significantly changed, and it was confirmed that the function as a polarizing film was sufficiently maintained.

<Evaluation of optical properties 2: Evaluation of waterproofness by immersion in hot water>
The coated polarizing film A and polarizing films B to E of Example 1 and Comparative Examples 1 to 4 were immersed in pure water at 80 ° C. until the aluminum was oxidized by water and 80% of the aluminum surface became transparent. Time was measured (Table 1). In both the coating layer configuration of only the first coating layer 1 (Comparative Examples 2 to 4) and the coating layer configuration of only the second coating layer 2 (Comparative Example 1), the aluminum surface becomes transparent within 30 minutes, The polarization performance has been completely lost. On the other hand, it was confirmed that the polarization characteristics of Example 1 were maintained without being deteriorated in transparency for 5 hours or more.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effects of the present invention are exhibited.

  The present invention can be applied to improve the durability of a wire grid polarizing plate. For example, as a vehicle-mounted optical application, used as a head-up display, a car navigation monitor, a polarizing plate in an instrument panel, a half mirror mounted room mirror, etc. It can be suitably applied to. Others include polarizing plates for cameras and displays in water and hot and humid environments, polarized glasses and lenses that are expected to be used in various temperature and humidity environments, head mounted displays, window materials and dressing tables, bathrooms It is also possible to apply to a half mirror such as.

DESCRIPTION OF SYMBOLS 10 Wire grid polarizing plate 11 Convex part 101 Base material 102 Metal wire layer 103 1st coating layer 104 2nd coating layer

Claims (6)

A substrate;
A metal wire layer extending in a certain direction at regular intervals on the surface of the substrate;
A first coating layer containing at least one of an inorganic material and a metal oxide material that coats at least the surface of the metal wire layer;
A second coating layer comprising a fluorine-containing composition that coats at least the surface of the first coating layer;
A wire grid polarizing plate characterized by comprising:   The wire grid polarizing plate according to claim 1, wherein an area of the surface of the first coating layer is larger than an area of the surface of the metal wire layer.   The wire grid polarizer according to claim 1 or 2, wherein the first coating layer coats the metal wire layer and a boundary portion between the metal wire and the base material simultaneously.   The said 2nd coating layer contains at least 1 type of coupling agent chosen from the group which consists of a fluorine-type silane coupling agent, a fluorine-type aluminate coupling agent, and a fluorine-type titanate coupling agent. The wire grid polarizing plate according to any one of claims 1 to 3.   The metal wire layer is in contact with a side surface on one side of the base convex portion having a grid-like concave / convex shape extending in a specific direction on the surface of the base, and extends upward from the top of the base convex portion. The wire grid polarizing plate according to claim 1, wherein the wire grid polarizing plate is provided. A first coating containing at least one of an inorganic material and a metal oxide material on the surface of a laminate comprising a substrate and a metal wire layer extending in a certain direction at regular intervals on the surface of the substrate. Forming a layer by sputtering;
Forming a second coating layer having a fluorine-containing composition on the surface of the first coating layer surface by a wet method;
The manufacturing method of the wire grid polarizing plate characterized by the above-mentioned.

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