JP2008176302A - Optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical element the optical characteristics of which are hardly affected even when the surface of the optical element is rubbed or scratched by a conveying roll or the like and which has the function of polarizing and separating light. <P>SOLUTION: The optical element is obtained by layering a transparent resin layer A, a grid consisting of a plurality of light-absorptive films which are extended slenderly and linearly and arranged almost in parallel in states parted from one another, and another transparent resin layer B in this order. The transparent resin layer B has a convex structure B on the grid-side surface. The convex structure has a plurality of convex parts b. A space is formed by the convex parts b between the transparent resin surface B and the grid and filled with air or an inert gas. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical element. More specifically, the present invention relates to an optical element having a polarization separation function or the like that hardly affects the optical characteristics even if the surface is rubbed or scratched by a transport roll or the like.

  A grid polarizer is known as a polarizer whose polarization plane can be freely set. This is an optical member having a grid structure in which a large number of linear metals (wires) are arranged in parallel at a constant period. When such a metal grid structure is formed, when the period of the grid is shorter than the wavelength of the incident light, the polarization component parallel to the linear metal forming the grid structure is reflected and the vertical polarization component is Since it transmits, it functions as a polarizer that produces a single polarized light. It has been proposed that this grid polarizer is used as an optical component of an isolator in optical communication, and as a component for increasing light utilization and improving luminance in a liquid crystal display device.

Since the grid structure of the grid polarizer is a very fine and delicate structure, a defect may occur in the grid structure when the surface is rubbed or scratched. Therefore, the grid polarizer is provided with a protective layer in order to protect the grid structure.
Patent Document 1 discloses that one side of a film having a higher order structure in which crystal parts and amorphous parts are alternately connected, or a film having a higher order structure in which two phases having different glass transition temperatures are alternately connected in the stretching direction, or Forming a composite film by forming a conductive thin film on both sides to obtain a composite film, stretching the composite film, and heat-fixing it to form an anisotropic conductive part and a polymer dielectric part Is disclosed. Further, it is described that a protective layer is provided on this film. However, when the protective layer is simply bonded on the grid, the resin or the like used for bonding the protective layer enters between the grids, and the polarization separation characteristics are deteriorated.
JP 2005-148416 A

Patent Document 2 discloses a polarizing device having a polarizer, and the polarizer includes a light-transmitting substrate, a grid wire that is sensitive to the surrounding environment disposed on the substrate, and a sealing surrounding member that surrounds the polarizer. A polarizing device is disclosed, wherein the surrounding member has an inert atmosphere to protect the polarizing element from the surrounding environment. This sealing enclosing member is provided so as not to contact the grid wire via a spacer attached to the side of the polarizer. However, when the optical element has a large area, the sealing enclosure member may be bent, and the shape stability may not be maintained.
JP 2005-513547 A (US Publication No. 2003-117708)

  An object of the present invention is to provide an optical element having excellent polarization separation characteristics that hardly affects the optical characteristics even if the surface is rubbed or scratched by a transport roll or the like.

  As a result of intensive studies to achieve the above object, the present inventor has a convex structure B on the grid side surface as a protective layer of the grid polarizer, and the convex structure B is composed of a plurality of convex portions b. A certain transparent resin film is used, a space is formed between the transparent resin film and the grid by the convex portion b, and the surface is rubbed or scratched by being filled with air or an inert gas. However, it has been found that the optical characteristics are hardly affected. The present invention has been completed as a result of further investigation based on this finding.

That is, the present invention includes the following aspects.
(1) The transparent resin layer A, a grid composed of a plurality of light-absorbing films that are elongated and linearly extended and spaced apart from each other, and the transparent resin layer B are laminated in this order,
The transparent resin layer B has a convex structure B on the grid side surface, and the convex structure B includes a plurality of convex portions b, and a space is formed between the transparent resin layer B and the grid by the convex portions b. The optical element, wherein the space is filled with air or an inert gas.
(2) The optical element described above, wherein the height of the convex portion b is 50 nm to 100 μm, and the grid is laminated in contact with the top surface of the convex portion b directly or via another layer.
(3) The optical element as described above, which has a long shape.
(4) The above-described optical element, wherein the convex structure B has a structure in which a plurality of eaves-like convex portions b extending in a linear shape are arranged in a separated state.
(5) The said optical structure B is the said optical element which has comprised the eaves-like uneven | corrugated structure elongated and linearly.
(6) The above-described optical element, wherein the convex structure B has a structure in which elongate convex portions b elongated in a linear shape are arranged in a lattice pattern.
(7) The above-described optical element, wherein the convex structure B has a structure in which a plurality of trapezoidal convex portions b are arranged in a discrete state.
(8) The transparent resin layer A has a convex structure A composed of a plurality of hook-shaped convex portions a that are elongated in a linear shape on the surface on the grid side and are arranged apart from each other.
The said optical element is comprised by the light absorption film formed in the top face of this convex part a, or the top surface and bottom face of this convex part a.

According to the optical element of the present invention, the convex structure A (or grid) is protected by the transparent resin layer B having the convex structure B, and the surface is rubbed or scratched with a transport roll or the like. Since the fine convex structure A (or grid) is hardly damaged, optical characteristics such as a polarization separation function expressed by the fine convex structure A (or grid) are not deteriorated.
Further, the convex structure B keeps a space between the transparent resin layer B and the grid, so that resin or the like does not enter between the grids, and the polarization separation characteristic does not deteriorate.
In addition, the optical element of the present invention has high operability because it is resistant to friction and scratching. By using the optical element of the present invention, a polarization separation film and the like can be produced with high efficiency.

The figure which shows the one aspect | mode of the transparent resin layer B of this invention optical element. The figure which shows another one aspect | mode of the transparent resin layer B of this invention optical element. The figure which shows another one aspect | mode of the transparent resin layer B of this invention optical element. The figure which shows another one aspect | mode of the transparent resin layer B of this invention optical element. The figure which shows the state before superimposing the transparent resin layer B shown in FIG. 1 and the transparent resin layer A in which the grid was formed on the surface.

Explanation of symbols

b: convex part b
B: Transparent resin layer B
A: Transparent resin layer A
G: Grid

  The optical element of the present invention is formed by laminating a transparent resin layer A, a grid composed of a plurality of light-absorbing films that are elongated and linearly extended and spaced apart from each other, and a transparent resin layer B in this order. Is.

  The transparent resin layer A is a film-like or sheet-like layer made of a transparent resin. The transparent resin preferably has a glass transition temperature of 60 to 200 ° C, more preferably 100 to 180 ° C from the viewpoint of processability. The glass transition temperature can be measured by differential scanning calorimetry (DSC).

Transparent resins include polycarbonate resin, polyethersulfone resin, polyethylene terephthalate resin, polyimide resin, polymethyl methacrylate resin, polysulfone resin, polyarylate resin, polyethylene resin, polyvinyl chloride resin, cellulose diacetate, cellulose triacetate, alicyclic ring And olefin polymers.
Of these, alicyclic olefin polymers are preferred from the viewpoints of transparency, low hygroscopicity, dimensional stability, and processability.

  Examples of the alicyclic olefin polymer include a cyclic olefin random multiple copolymer described in JP-A No. 05-310845, a hydrogenated polymer described in JP-A No. 05-97978, and JP-A No. 11-124429. And thermoplastic dicyclopentadiene-based ring-opening polymers and hydrogenated products thereof described in US Pat. No. 6,511,756.

  The transparent resin used in the present invention contains coloring agents such as pigments and dyes, fluorescent brighteners, dispersants, heat stabilizers, light stabilizers, ultraviolet absorbers, antistatic agents, antioxidants, lubricants, solvents, etc. An agent may be appropriately blended.

  The transparent resin layer A is obtained by molding the transparent resin by a known method. Examples of the molding method include a cast molding method, an extrusion molding method, and an inflation molding method.

The average thickness of the transparent resin layer A is usually 5 μm to 1 mm, preferably 20 to 200 μm from the viewpoint of handleability. The transparent resin layer A preferably has a light transmittance in the visible region of 400 to 700 nm of 80% or more.
The transparent resin layer A, the retardation Re (Re = d × (n x -n y) defined in the value, n _x and n _y are in-plane principal refractive transparent resin layer A were measured at that wavelength 550nm It is not particularly limited by the ratio ( _nx ≧ _ny ); d is the average thickness of the transparent resin layer A). The difference between the retardation Re at any two points in the plane (retardation unevenness) is preferably 10 nm or less, and more preferably 5 nm or less. When the retardation unevenness is large, the brightness of the display surface tends to vary when used in a liquid crystal display device.

  In the present invention, a long transparent resin layer A is preferably used. “Long” means a material having a length of at least about 5 times the width, preferably a material having a length of 10 times or more, and specifically wound and stored in a roll shape. Or what has the length of the grade carried. The width of the transparent resin layer A is preferably 500 mm or more, more preferably 1000 mm or more.

  The grid used in the optical element of the present invention is composed of a plurality of light-absorbing films that are elongated and linear, and are arranged in parallel in a state of being separated from each other. The light-absorbing film constituting the grid preferably has a width of 25 to 300 nm and a length of preferably 800 nm or more. The pitch of the grid is preferably 20 to 500 nm, more preferably 30 to 300 nm. The grid may be one in which thin films are arranged aperiodically, but one in which thin films are arranged in order to obtain optical characteristics such as polarization separation is preferable.

The light absorbing film is obtained by forming a light absorbing material.
The light-absorbing material is preferably a conductive material, and specific examples include metals such as aluminum, indium, magnesium, rhodium and tin. The film forming method is not particularly limited, and examples thereof include a wet plating method and a dry plating method.

A method of forming a grid composed of a plurality of light-absorbing films that are elongated and linearly extended and spaced apart from each other is not particularly limited, but is preferably formed by the following method.
First, a convex structure A is formed on at least one surface of the transparent resin layer A in which a plurality of elongate protrusions a extending in a linear shape are arranged substantially in parallel with each other being separated from each other.
The convex structure A preferably has a structure in which a plurality of eaves-like protrusions a that are elongated in a linear shape are arranged in a state of being separated from each other, and in particular, an eaves-like protrusion a that is elongated and linearly extends. Are preferably arranged in a lattice pattern. The wrinkle-shaped convex part a has a wrinkle width of preferably 25 to 300 nm, and a wrinkle length of preferably 800 nm or more.

Moreover, the center-to-center distance (pitch) of the convex part a is preferably 20 to 500 nm, more preferably 30 to 300 nm. The height of the convex part a is preferably 5 to 3000 nm, more preferably 20 to 1000 nm, and particularly preferably 50 to 300 nm.
The convex structure A may be one in which the convex portions a are arranged aperiodically, but preferably one in which the convex portions a are arranged periodically in order to obtain optical properties such as polarization separation.

  The method for forming the convex structure A is not particularly limited. For example, (1) the transfer roll having a shape corresponding to the convex structure A is used to transfer to the surface of the long resin raw film, or (2) the pattern of the convex structure A is transferred by a photolithographic method. Is obtained by

Next, a light-absorbing film is laminated on the convex structure A by the PVD method.
The PVD method is a method of forming a film by evaporating and ionizing a vapor deposition material. Specifically, it can be appropriately selected from vacuum deposition, sputtering, ion plating (ion plating), ion beam deposition, and the like. Of these, vacuum deposition is preferred. The vacuum deposition method is a method of forming a thin film by heating a vapor deposition material in a vacuumed container, vaporizing or sublimating it, and attaching it to the surface of a substrate placed at a remote position. Heating is performed by a method such as resistance heating, electron beam, high frequency induction, or laser depending on the type of deposition material or substrate. The thickness of the light-absorbing film to be laminated is not particularly limited, but is usually 20 to 500 nm, preferably 30 to 300 nm, more preferably 40 to 200 nm. The thickness of the light-absorbing film is the thickness of the light-absorbing film laminated on the top surface of the convex portion.

  A light-absorbing film is preferentially laminated on the top surface of the convex part a of the convex structure A by film formation by the PVD method. On the other hand, a light-absorbing film is difficult to be laminated on the side surface of the convex part a, but when the distance between the centers of the convex parts a is wide, a light-absorbing film is also laminated on the bottom surface of the concave part formed between the two convex parts a. Sometimes. The light-absorbing film laminated on the bottom surface of the recess can be removed by a wet etching process as will be described later.

The light-absorbing film laminated by the PVD method is usually wider than the width of the convex part a. Since it is preferable that the width of the light-absorbing film is narrow, it is preferable that an inorganic compound film is laminated by the PVD method on the light-absorbing film laminated by the PVD method as a wet etching mask described later, and then etched.
The inorganic compound is not particularly limited as long as it can withstand wet etching described later, and examples thereof include compounds such as silicon oxide, silicon nitride, silicon carbide, and silicon nitride oxide. Of these, silicon oxide is particularly preferred. The thickness of the laminated inorganic compound film is not particularly limited, but is usually 1 to 100 nm, preferably 2 to 50 nm, and more preferably 3 to 20 nm.
Since the light-absorbing film laminated by the PVD method has a width that is usually wider than the width of the convex portion a and narrows the entrance of the concave portion of the convex structure A, the inorganic compound film is mainly formed on the top surface of the convex portion. It is laminated | stacked on the light absorption film | membrane laminated | stacked on.

  In order to reduce the width of the light-absorbing film laminated on the top surface of the convex portion a and remove the light-absorbing film laminated on the concave portion of the convex structure A, it is preferable to perform wet etching. The etching solution used in the wet etching method may be any solution that can remove the light-absorbing film without corroding the transparent resin layer, depending on the material of the mask layer (inorganic compound film), the light-absorbing film, and the transparent resin layer. Select as appropriate. Examples of wet etching solutions include solutions containing alkali metal compounds such as sodium hydroxide and potassium hydroxide; solutions containing sulfuric acid, phosphoric acid, nitric acid, acetic acid, hydrogen fluoride, hydrochloric acid, etc .; ammonium persulfate, hydrogen peroxide, fluorine A solution made of ammonium fluoride or the like or a mixture thereof may be used. Moreover, you may add additives, such as surfactant, to a wet etching liquid.

  By this etching, the light-absorbing film under the portion where the mask layer is not laminated or the portion where the mask layer is thin is removed. Specifically, the side part of the light-absorbing film laminated on the top of the convex part a and the light-absorbing film laminated on the bottom surface of the concave part of the convex structure A are removed, and the width of the convex part is about the same as the width of the convex part. An absorptive membrane with a width of The grid can be easily formed as described above.

After the grid is formed on the transparent resin layer A by the method as described above, the transparent resin layer B is laminated as a protective layer.
The transparent resin layer B has a convex structure B on the grid side surface, and the convex structure B includes a plurality of convex portions b.
The average thickness of the transparent resin layer B is usually 5 μm to 1 mm, preferably 20 to 200 μm, from the viewpoint of handleability. The transparent resin layer B preferably has a light transmittance in the visible region of 400 to 700 nm of 80% or more.
The transparent resin layer B is defined as a value in the retardation Re (Re = d × measured (n _x -n _y) at that wavelength 550 nm, n _x and n _y are in-plane principal refractive transparent resin layer B It is not particularly limited by the ratio ( _nx ≧ _ny ); d is the average thickness of the transparent resin layer B). The difference between the retardation Re at any two points in the plane (retardation unevenness) is preferably 10 nm or less, and more preferably 5 nm or less. When the retardation unevenness is large, the brightness of the display surface tends to vary when used in a liquid crystal display device.

Although the convex part b which comprises the convex structure B is not restrict | limited especially by the arrangement | positioning, a shape, etc., The height of the convex part b becomes like this. Preferably it is 50 nm-100 micrometers, More preferably, it is 100 nm-50 micrometers. Then, the grid is laminated in contact with the top surface of the convex portion b directly or through another layer.
The convex portion b is a long and narrow bowl-like shape (FIGS. 1 and 4), or a circular or elliptical shape when viewed from the top surface; a trapezoidal shape having a polygonal shape such as a triangle or a rectangle ( 2 and 3). From the viewpoint of not deteriorating optical characteristics, a trapezoidal one is preferable.

  When it has a long and narrow eaves-like structure, it may have a structure as shown in FIG. 1 or a prism structure as shown in FIG. When it has a prism structure, it may be a regular structure or an irregular structure. In the case of an irregular prism structure, the pitch is about 20 to 60 μm. It is preferable to install a prism structure on the light source side because it can provide not only a protective layer but also a light collecting property. The transparent resin layer having a prism structure may be commercially available as a brightness enhancement film.

In the case of a trapezoidal shape, the size of the table is not particularly limited, but the passing length when viewed from above is preferably 50 nm to 500 μm, more preferably 150 nm to 250 μm. The base may be of the same size (columnar shape) from the top to the bottom, may be a cone having a small top and a large bottom, or a reverse taper having a large top and a small bottom.
The center-to-center distance of the protrusions b is 5 to 1000 times, specifically 150 nm to 1 mm, preferably 10 to 500 times, and specifically 300 nm to 500 μm.

In the case of a trapezoidal shape, the area occupied by the convex part b is preferably 50% or less, more preferably 30% or less, and particularly preferably 15% or less of the area of the main surface of the transparent resin layer B. If the area occupied by the convex portion b is too large, the optical characteristics tend to deteriorate. In order to obtain the effect of the present invention, it is preferable that the convex portion b occupies 5% or more of the area of the main surface of the transparent resin layer B.
In the case of a trapezoidal shape, the convex structure B may be one in which the convex portions b are arranged aperiodically, but the convex portions b are arranged periodically in order to reduce in-plane unevenness of the optical characteristics. Those are preferred.

  The convex structure B is not particularly limited by the formation method. For example, 1) a method of transferring the pattern of the convex structure B by pressing a transfer roll having a concavo-convex shape corresponding to the convex structure B against the surface of the transparent resin film, and 2) applying a coating liquid composed of resin and particles to the transparent resin film A method of forming a pattern of the convex structure B by applying to the surface, 3) having a core-shell structure, the melting temperature of the core is higher than the melting temperature of the shell, and the melting temperature of the shell is equal to or lower than the lamination temperature at the time of lamination A method of forming a pattern of the convex structure B by dispersing such particles between the transparent resin layer A having the grid structure and the transparent resin film and then laminating at a temperature equal to or higher than the melting temperature of the shell, etc. It is done.

1) A method of transferring a pattern of a convex structure B by pressing a transfer roll having a concave and convex shape corresponding to the convex structure B against the surface of the transparent resin film. In this method, a fine convex structure B is formed by focused ion beam (FIB) processing or the like. A (spacer pattern) cutting tool is manufactured, and a groove corresponding to the fine convex structure B is cut with a cutting tool on a metal mold base to form a transfer mold. The convex structure B can be formed by pressing and transferring the mold to the transparent resin film.
The method is not particularly limited as long as the transfer die is formed by transferring the shape of the bite to the mold base material after the bite is manufactured. For example, the method described in JP-A-2006-17879 is used. Can do.

The transparent resin film used for this method is a film-like or sheet-like layer made of a transparent resin. The transparent resin can be appropriately selected and used from those shown as constituting the transparent resin layer A described above.
The average thickness of the transparent resin film is usually 5 μm to 1 mm, preferably 20 to 200 μm from the viewpoint of handleability. The transparent resin film preferably has a light transmittance in the visible region of 400 to 700 nm of 80% or more.

Further, the transparent resin film, retardation Re (Re = d × (n x being defined value -n _y), n _x and n _y are in-plane principal refractive index of the transparent resin layer B was measured at that wavelength 550nm ( _Nx > _ny ); d is an average thickness of the transparent resin layer B), and is not particularly limited. The difference between the retardation Re at any two points in the plane (retardation unevenness) is preferably 10 nm or less, and more preferably 5 nm or less. When the retardation unevenness is large, the brightness of the display surface tends to vary when used in a liquid crystal display device.

  An adhesive (including a pressure-sensitive adhesive) can be used for laminating the transparent resin layer B obtained by the technique. The average thickness of the layer (adhesive layer) made of an adhesive interposed between the grid top surface and the transparent resin layer B is usually 0.01 μm to 30 μm, preferably 0.1 μm to 15 μm. As this adhesive, acrylic adhesive, urethane adhesive, polyester adhesive, polyvinyl alcohol adhesive, polyolefin adhesive, modified polyolefin adhesive, modified alicyclic olefin adhesive, polyvinyl alkyl ether adhesive, rubber adhesive, Vinyl chloride / vinyl acetate adhesive, styrene / butadiene / styrene copolymer (SBS copolymer) adhesive, hydrogenated product (SEBS copolymer) adhesive, ethylene / vinyl acetate copolymer and ethylene-styrene copolymer Ethylene adhesives such as polymers, and acrylic acid such as ethylene / methyl methacrylate copolymer, ethylene / methyl acrylate copolymer, ethylene / ethyl methacrylate copolymer, and ethylene / ethyl acrylate copolymer Examples include ester adhesives.

2) A method of forming a pattern of convex structure B by applying a coating solution composed of a resin and particles on the surface of a transparent resin film. This method prepares a coating solution composed of a resin and particles, and the coating solution is used as a resin film. This is a technique for producing a convex structure B derived from the particle size of the particles by applying to the surface and drying.
Examples of the transparent resin film and resin used in the method 2) include the same films and resins described above.
The particles are not particularly limited as long as they are transparent particles, and examples thereof include inorganic particles and organic particles.

Examples of inorganic particles include silica particles and metal particles. In addition, a thin film such as a metal oxide such as silicon oxide, zinc oxide, titanium oxide, or zirconium oxide; a metal fluoride such as MgF ₂ ; is formed on the surface of the core particles such as glass particles, metal particles, and synthetic resin particles. The formed particles can also be used.
Examples of the organic particles include organic particles such as silicone resin particles, acrylic resin particles, nylon resin particles, urethane resin particles, styrene resin particles, polyethylene resin particles, and polyester resin particles. In addition, composite particles in which an organic film is formed on the surface of the inorganic particles can be used.

The particle size of the particles is not particularly limited, but from the viewpoint of easy formation of the convex structure B, the average particle size is preferably 1 to 50 μm, more preferably 3 to 30 μm, and particularly preferably 5 to 20 μm.
The shape of the particles is not particularly limited, but spherical, elliptical, crushed or polyhedral particles can be used, and spherical and elliptical shapes are preferred.
In the coating solution composed of the resin and particles described above, the amount of the particles is usually 0.01 to 100 parts by weight, preferably 0.1 to 50 parts by weight, more preferably 0.5 to 20 parts per 100 parts by weight of the resin. Parts by weight.

The method for dispersing the particles in the resin is not particularly limited, and a known method can be adopted. For example, there is a method in which both are mechanically mixed with a Hensche mixer, tumbler, etc., and then melt-kneaded with a Banbury mixer, a single-screw or twin-screw extruder, but the resulting coating solution has uniform particles in the resin. It is preferable that they are dispersed.
In addition, the coating solution may contain a solvent, and the solvent is not particularly limited as long as the resin dissolves therein, and is an aromatic solvent such as toluene and xylene; a ketone solvent such as methyl ethyl ketone and methyl isobutyl ketone; An ester solvent such as ethyl acetate or butyl acetate can be used. When the solvent is contained, a step of drying the solvent is necessary. The drying of the solvent is not particularly limited as long as it is at or above the temperature at which the solvent volatilizes, but it is preferable to dry at a temperature not higher than the boiling point of the solvent from the viewpoint of reducing defects.

3) Transparent resin layer A, transparent resin having a core-shell structure, in which the core melting temperature is higher than the melting temperature of the shell and the shell melting temperature is equal to or lower than the laminating temperature at the time of lamination, and the grid structure is formed Method of forming pattern of convex structure B by spreading between films and then laminating at a temperature equal to or higher than the melting temperature of the shell The method is such that the melting temperature of the core is higher than the melting temperature of the shell and the melting temperature of the shell By spraying particles having a core-shell structure whose temperature is equal to or lower than the lamination temperature at the time of lamination between the transparent resin layer A and the transparent resin film having the grid structure, and laminating at a temperature equal to or higher than the melting temperature of the shell. In this method, the pattern of the convex structure B is formed on the transparent resin film.
Examples of the transparent resin film used in the method 3) include the same films as those described above.

It may be described as particles having a core-shell structure (hereinafter referred to as “core-shell particles”). ) Is not particularly limited as long as the melting temperature of the core is higher than the melting temperature of the shell, and examples include particles composed of both the core and the shell, and composite particles composed of the inorganic core and the organic shell. The core-shell particles can be produced using an emulsion polymerization method, a seed polymerization method, a suspension polymerization method, or the like. The particles having organic cores and shells, for example, polymerize the monomer (A) whose homopolymer initially exhibits a high melting temperature, and form a high melting temperature portion at the center of the particle. Thereafter, the monomer (B) whose homopolymer exhibits a low melting temperature (melting temperature equal to or lower than the lamination temperature at the time of lamination) is added to the polymerization system, so that the central portion has a high melting temperature and the surface layer portion has a low melting temperature. The particles shown can be made. In addition, for the composite particles composed of an inorganic core and an organic shell, for example, a dispersion of inorganic particles is prepared, and the homopolymer has a low melting temperature (melting temperature equal to or lower than the lamination temperature during lamination) (B ) To the system, particles having a central portion made of an inorganic material and a surface layer portion made of an organic material can be produced.
The method of spraying the core-shell particles is not particularly limited, and examples thereof include a method of spraying the dispersion containing the core-shell particles as they are or using the spray.

  In the optical element of the present invention, the convex portion b serves as a spacer to form a space between the transparent resin layer B and the grid, and the space is filled with air or an inert gas. Examples of the inert gas include nitrogen and helium. FIG. 5 is a diagram illustrating an example of a state before the transparent resin layer B and the transparent resin layer A with the grid G formed on the surface are overlaid. When the transparent resin layer A and the transparent resin layer B are laminated in the arrangement as shown in FIG. 5, the top surface of the convex portion b on the surface of the transparent resin layer B is directly or via another layer (for example, an adhesive layer). Thus, it can be seen that the top of the grid G is in contact and the convex portion b is a spacer, and a space is formed between the transparent resin layer A and the transparent resin layer B.

  The optical element of the present invention has a property of transmitting one of linearly polarized light orthogonal to each other and reflecting the other. Utilizing the property of separating such linearly polarized light into transmitted light and reflected light, the optical element of the present invention can be used as it is as an element for improving the luminance of a liquid crystal display device or other optical element (polarizer, phase difference plate, etc.) ) And can be used in combination.

<Production Example 1> Production of Grid Polarized Film Focused ion beam on a 0.2 mm x 1 mm surface of a rectangular single crystal diamond of 0.2 mm x 1 mm x 1 mm brazed to an 8 mm x 8 mm x 60 mm SUS shank Using a processing device SMI3050 (manufactured by Seiko Instruments Inc.), focused ion beam processing using an argon ion beam is performed, and a groove having a width of 70 nm and a depth of 100 nm is engraved with a pitch of 140 nm, and a cutting tool is manufactured. did.
A cutting tool in which a nickel-phosphorus electroless plating with a thickness of 100 μm is applied to the entire curved surface of a cylindrical stainless steel SUS430 having a diameter of 200 mm and a length of 150 mm, and then a precision cylindrical grinding machine formed with the linear protrusions previously produced. By using S30-1 (manufactured by Studer), a linear protrusion having a width of 70 nm, a height of 100 nm, and a pitch of 140 nm is cut in a direction parallel to the circumferential end surface of the cylinder on the nickel-phosphorous electroless plating surface. A transfer roll was obtained. In addition, the production of the cutting tool by focused ion beam machining and the cutting of the nickel-phosphorus electroless plating surface are performed at a temperature of 20.0 ± 0.2 ° C. and vibration of 0.5 Hz or more by a vibration control system (manufactured by Showa Science). Was carried out in a constant-temperature low-vibration chamber whose displacement was controlled to 10 μm or less.

Using a nip roll made of a rubber roll having a diameter of 70 mm and a transfer apparatus using the transfer roll, the transfer roll surface temperature is 160 ° C., the nip roll surface temperature is 100 ° C., the film transport tension is 0.1 kgf / mm ² , and the nip Under the condition of a pressure of 0.5 kgf / mm, the shape of the surface of the transfer roll was transferred onto the surface of an alicyclic olefin polymer film (ZF-14, manufactured by Optes Co., Ltd.) having a thickness of 100 μm and wound into a roll. Next, on the pattern transfer surface of the film, an aluminum film was formed by sputtering at an output of 400 W in the presence of Ar gas, and wound into a roll to obtain a long grid polarizing film.

<Production Example 2> Production of cycloaliphatic olefin polymer having adhesion function In a nitrogen atmosphere, 500 parts by weight of dehydrated cyclohexane, 0.82 parts by weight of 1-hexene, 0.15 parts by weight of dibutyl ether and 0. 30 parts by weight were placed in a reactor at room temperature and mixed. While maintaining the reactor at 45 ° C., 9-ethylidene-tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene (hereinafter abbreviated as “ETCD”) 100 parts by weight and tungsten hexachloride 0.7% by weight toluene solution 40 parts by weight were added continuously over 2 hours for polymerization. did. 1.06 parts by weight of butyl glycidyl ether and 0.52 parts by weight of isopropyl alcohol were added to the polymerization solution to inactivate the polymerization catalyst, and the polymerization reaction was stopped to obtain a solution containing a ring-opening polymer. 270 parts by weight of cyclohexane is added to 100 parts by weight of the solution containing the ring-opening polymer, 5 parts by weight of a nickel-alumina catalyst (manufactured by JGC Chemical Co., Ltd.) is added as a hydrogenation catalyst, and the pressure is increased to 5 MPa with hydrogen. did. The solution was heated to 200 ° C. with stirring and reacted for 4 hours to obtain a solution containing 20% by weight of ETCD ring-opening copolymer hydride. The hydrogenation catalyst is removed by filtration, and then the hydride is melted while removing the solvent cyclohexane and other volatile components at a temperature of 270 ° C. and a pressure of 1 kPa or less using a cylindrical concentrating dryer (manufactured by Hitachi, Ltd.). In the state, it was extruded into a strand form from an extruder, cooled and pelletized to recover ETCD ring-opening copolymer hydride pellets. The obtained ETCD ring-opening copolymer hydride had a weight average molecular weight of 35,000 and a hydrogenation rate of 99.9%.

Next, 6.0 parts by weight of maleic anhydride, 2 parts by weight of dicumyl peroxide and 250 parts by weight of tert-butylbenzene were mixed with 100 parts by weight of the ETCD ring-opening polymer hydride, and 135 ° C. in an autoclave. The reaction was performed for 6 hours. The resin was precipitated by adding the reaction solution into a large amount of acetone, and the resin was recovered by filtration. The collected resin was dried at 100 ° C. and 1 Torr or less for 48 hours to obtain 105 parts by weight of maleic anhydride-modified alicyclic olefin polymer. The obtained maleic anhydride-modified alicyclic olefin polymer had a weight average molecular weight of 39,000 and a maleic anhydride modification amount of 10.0 mol% as measured by ¹ H-NMR.

Example 1
A focused ion beam processing apparatus SMI3050 (manufactured by Seiko Instruments Inc.) is used on a 0.2 mm × 1 mm surface of a rectangular single crystal diamond of 0.2 mm × 1 mm × 1 mm brazed to a SUS shank of 8 mm × 8 mm × 60 mm. Then, focused ion beam processing using an argon ion beam was performed, and a groove having a width of 300 nm and a depth of 500 nm parallel to a side having a length of 1 mm was carved at a pitch of 5 μm to produce a cutting tool.
A cutting tool in which a nickel-phosphorus electroless plating with a thickness of 100 μm is applied to the entire curved surface of a cylindrical stainless steel SUS430 having a diameter of 200 mm and a length of 150 mm, and then a precision cylindrical grinding machine formed with the linear protrusions previously produced. Cutting a linear structure having a width of 300 nm, a height of 500 nm, and a pitch of 5 μm in a direction parallel to the circumferential end surface of the cylinder on the nickel-phosphorus electroless plating surface using S30-1 (manufactured by Studer). Thus, a transfer roll was obtained. In addition, cutting tool fabrication by focused ion beam machining and cutting of nickel-phosphorous electroless plating surface are performed at a temperature of 20.0 ± 0.2 ° C and vibrations of 0.5 Hz or higher by a vibration control system (made by Showa Science). Was carried out in a constant-temperature low-vibration chamber whose displacement was controlled to 10 μm or less.

Using a nip roll made of a rubber roll having a diameter of 70 mm and a transfer device using the transfer roll, the transfer roll surface temperature is 160 ° C., the nip roll surface temperature is 100 ° C., the film transport tension is 0.1 kgf / mm ² , and the nip pressure The shape of the transfer roll surface was transferred onto the surface of an alicyclic olefin polymer film (ZF-14, manufactured by Optes Co., Ltd.) having a thickness of 100 μm under the condition of 0.5 kgf / mm, and wound into a roll. Next, a coating solution comprising 1.0 part by weight of an alicyclic olefin polymer having an adhesion function prepared in Production Example 2, 80.0 parts by weight of toluene, and 19.0 parts by weight of butyl acetate was prepared, and the transfer film was formed on the transfer film. The protective film 1 which has an uneven | corrugated shape on the surface was obtained by apply | coating, drying in a 120 degreeC drying furnace, and winding up in roll shape. The obtained protective film was cut into a predetermined size, and a TEM observation cross section was prepared using a micro sampling device of a focused ion beam processing observation device FB-2100 (manufactured by Hitachi, Ltd.), and a transmission electron microscope H-7500 (Hitachi) As a result of observing the cross section of the film at a manufacturing company, a rectangular protrusion having a width of 340 nm and a height of 440 nm was observed on the film surface. Further, the obtained protective film was cut into a 50 mm square, and the surface of the protective film 1 was observed using a three-dimensional surface structure analysis microscope (manufactured by Zygo). The entire surface of the film was rectangular in parallel with the width direction. A structure was formed in which the protrusions were periodically arranged at intervals of about 5 μm.

  Next, as shown in FIG. 5, the grid surface of the grid polarizing film produced in Production Example 1 and the projection surface of the protective film 1 are supplied to a nip of a pressure roller adjusted to a surface temperature of 80 ° C. and pressure bonded. The grid polarizing film 1 which has a protective layer was produced by pasting together. The obtained grid polarizing film 1 is cut into a predetermined size, and an observation cross section for TEM is prepared using a microsampling apparatus of a focused ion beam processing observation apparatus FB-2100 (manufactured by Hitachi, Ltd.) for arbitrary 10 points, and transmitted. As a result of observing the cross section of the film with an electron microscope H-7500 (manufactured by Hitachi, Ltd.), an air layer is formed between the protrusions formed on the protective film 1, and the grid that is not in contact with the protective film 1 from the measurement results The area of the layer was calculated to be about 93%.

Example 2
A coating solution comprising 7.0 parts by weight of an acrylic resin (Parapet GH1000S, manufactured by Kuraray), 3.0 parts by weight of silica particles (Tospearl 120, manufactured by Toshiba GE Silicone), and 90.0 parts by weight of butyl acetate is prepared. The protective film 2 was obtained by apply | coating on a 100 micrometer alicyclic olefin polymer film (ZF-14, product made from Optes Co., Ltd.), and drying with a 120 degreeC drying furnace.
When the protective film 2 is cut into a 50 mm square and the surface of the protective film 2 is observed using a three-dimensional surface structure analysis microscope (manufactured by Zygo), circular protrusions are irregularly formed on the film surface. The average height at 10 points was calculated to be 1 μm.

  Next, the grid layer of the grid polarizing film produced in Production Example 1 and the protruding surface of the protective film 2 are supplied to the nip of a pressure roller adjusted to a surface temperature of 100 ° C. The grid polarizing film 2 which has was produced. The obtained grid polarizing film 2 is cut into a predetermined size, and an observation cross section for TEM is prepared and transmitted through a microsampling device of a focused ion beam processing observation apparatus FB-2100 (manufactured by Hitachi, Ltd.) for any 10 points. The film cross section was observed with an electron microscope H-7500 (manufactured by Hitachi, Ltd.). As a result, since air layers are formed between the protrusions formed on the protective film 2 at all measurement points, the grid polarizing film 2 has a grid layer that is not in contact with the protective film. Was confirmed. It was about 85% when the area of the grid layer which is not contacting with the protective film was computed from the measurement result.

Example 3
A stainless steel reactor was charged with 75 parts by weight of deionized water, 0.8 parts by weight of polyvinyl alcohol as a dispersant, and 0.8 parts by weight of benzoyl peroxide as a radical initiator. And 2 parts by weight of divinylbenzene were added and emulsified by stirring. This emulsion was transferred to a separately degassed autoclave using a homogenizer, and the temperature was raised to 65 ° C. to perform polymerization for 2 hours. The particle diameter of the polymer particles at that time is 9.4 μm, and since the particles cannot be melted even at 150 ° C., the melting temperature is 150 ° C. or higher. Next, 250 parts by weight of deionized water, 3 parts by weight of polyvinyl alcohol as a dispersant, and 2.5 parts by weight of benzoyl peroxide as a radical initiator were added and degassed under reduced pressure. Next, 100 parts by weight of glycidyl methacrylate and 100 parts by weight of cyclohexyl acrylate were emulsified and added to the autoclave for polymerization for 2 hours. Next, the polymerization was terminated by cooling to obtain a polymer bead dispersion. The polymer bead dispersion was filtered, washed, dried, and sieved (particles of 50 μm or more were removed) to obtain core-shell particles. The obtained particles had an average particle diameter of 19.5 μm, and when the melting temperature of the shell part of the obtained particles was measured, the melting temperature was 55 ° C.

  Next, the core-shell particles were dispersed on the surface of the grid polarizing film prepared in Production Example 1, and an alicyclic olefin polymer film (ZF-14, manufactured by Optes Co., Ltd.) having a thickness of 100 μm as a protective film was laminated. . The grid polarizing film 3 which has a protective layer was produced by supplying and bonding to the nip of the pressure roller adjusted to surface temperature 80 degreeC. The obtained grid polarizing film 3 was cut out to a predetermined size, and an observation cross section for TEM was prepared using a microsampling device of a focused ion beam processing observation device FB-2100 (manufactured by Hitachi, Ltd.) for any 10 points, and transmitted. The film cross section was observed with an electron microscope H-7500 (manufactured by Hitachi, Ltd.). As a result, an air layer was formed between the particles serving as spacers at all measurement points. Further, the grid polarizing film 3 was heated to 100 ° C., and after the protective film was peeled off, it was cut into a 50 mm square, and the surface of the protective film was observed using a three-dimensional surface structure analysis microscope (manufactured by Zygo). The area of the grid layer not in contact with the protective film was about 44%.

Comparative Example 1
The grid polarizing film 4 was obtained by cutting out the long grid polarizing film produced in the manufacture example 1 in a 50 mm square.

Comparative Example 2
A coating solution comprising 10 parts by weight of an alicyclic olefin polymer having an adhesive function produced in Production Example 2, 70 parts by weight of xylene and 20 parts by weight of butyl acetate was prepared, and an alicyclic olefin polymer film having a thickness of 100 μm (trade name) : ZF-14, manufactured by Optes Co., Ltd.) and dried in a drying furnace at 120 ° C. to obtain a protective film.
Next, the grid polarizing film 5 produced in Production Example 1 and the protective film were supplied to a nip of a pressure roller adjusted to a surface temperature of 100 ° C. and pressure-bonded to produce a grid polarizing film 5 having a protective layer. . The grid polarizing film 5 is cut into a predetermined size, and an observation cross section for TEM is prepared using a micro sampling device of a focused ion beam processing observation device FB-2100 (manufactured by Hitachi, Ltd.) for an arbitrary 10 points. The film cross section was observed with -7500 (manufactured by Hitachi, Ltd.). As a result, an air layer was not formed between the protective film and the base film at all measurement points. (The area of the grid layer not in contact with the protective film is 0%).

(Adhesion test: adhesion)
In accordance with JIS K5400 method, cut in a grid pattern of 1 mm x 1 mm from the protective layer side of the grid polarizing film, perform a peel test with an adhesive tape (24 mm width, specified in JIS Z1522), and the protective layer is an adhesive tape Measure the number of squares moved to the side. The case where the number of cells moved to the adhesive tape side is 5 or less is marked with ◯, and the case where the number is 5 or more is marked with x.

(Scratch test)
The entire surface of the grid polarizing film was contacted with steel wool # 0000 at a load of 0.01 MPa and reciprocated five times. The state of the grid polarizing film surface was visually observed. In addition, it is set as (circle) when the grid polarizing film surface does not have a crack.

(Measurement of brightness improvement effect before and after scratch test)
The grid polarizing film immediately after production and immediately after the scratch test was used for evaluation. A light diffusing sheet and the grid polarizing film were sequentially laminated on the light exiting side of the light guide plate in which the cold cathode tube was disposed on the incident end face side and the light reflecting sheet was provided on the back side, thereby producing a polarized light source device.
Furthermore, the absorption type polarizing plate is laminated so that the transmission axis of the absorption type polarizing plate is parallel to the transmission axis of the grid polarizing film (not required when the grid polarizing film is a laminate with the absorption type polarizing plate), and the transmission type The TN liquid crystal display element was placed, and the absorptive polarizing plate was placed so that the transmission axis was oriented in a direction perpendicular to the transmission axis of the absorptive polarizing plate under the liquid crystal display element to produce a liquid crystal display device. The front luminance during bright display of the obtained liquid crystal display device was measured using a luminance meter BM-7 (manufactured by Topcon).

Claims (8)

A transparent resin layer A, a grid composed of a plurality of light-absorbing films that are elongated and linearly extended and spaced apart from each other, and a transparent resin layer B are laminated in this order,
The transparent resin layer B has a convex structure B on the grid side surface, and the convex structure B includes a plurality of convex portions b, and a space is formed between the transparent resin layer B and the grid by the convex portions b. An optical element, wherein the space is filled with air or an inert gas.   The optical element according to claim 1, wherein the height of the convex part b is 50 nm to 100 μm, and the grid is in contact with the top surface of the convex part b directly or via another layer.   The optical element according to claim 1, wherein the optical element is long.   The optical element according to any one of claims 1 to 3, wherein the convex structure B has a structure in which a plurality of eaves-like convex parts b extending in a linear shape are arranged in a state of being separated from each other.   The optical element according to any one of claims 1 to 3, wherein the convex structure B forms an eaves-like concavo-convex structure elongated in a linear shape.   4. The optical element according to any one of claims 1 to 3, wherein the convex structure B has a structure in which elongate convex portions b extending in a linear shape are arranged in a lattice pattern.   4. The optical element according to any one of claims 1 to 3, wherein the convex structure B has a structure in which a plurality of trapezoidal convex portions b are arranged in a discrete state. The transparent resin layer A has a convex structure A composed of a plurality of bowl-shaped convex portions a that are elongated in a linear shape on the surface on the grid side and are arranged in a separated state from each other,
The optical element according to any one of claims 1 to 7, wherein the grid is constituted by a light-absorbing film formed on a top surface of the convex portion a or on a top surface and a bottom surface of the convex portion a. .

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