JP2007069604A - Pattern forming method, pattern forming sheet and optically functional sheet formed using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for patterning a function material on a base material simply and inexpensively, a pattern forming sheet and an optically functional sheet using the patterning method. <P>SOLUTION: This pattern forming method is constituted so as to pattern a surface layer on a laminate, which is composed of a base material layer and the surface layer formed on one side or both sides of the base material layer by the transfer of a mold. (A) The surface layer contains at least metal fine particles or metal coated fine particles formed by coating the surface with a metal and (B) the mold has a surface shape wherein the height H of the protruded part of the mold is larger than the film thickness L of the surface layer and the cross-sectional area S2 of the recessed part of the mold is larger than the cross-sectional area S1 of the surface layer and is pressed to the surface layer of the laminate to penetrate the surface layer by the protruded part of the mold. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a method for patterning a substrate surface by mold transfer, a pattern forming sheet, and a pattern in which a surface layer containing at least metal fine particles or metal-coated fine particles is arranged on the substrate surface. The present invention relates to an optical functional sheet.

  In recent years, the importance of a technique for forming a fine structure is increasing in various fields such as the optical field and the semiconductor field.

  In the optical field, a high-precision fine structure forming technique is required. In the semiconductor field, in addition to a high-precision fine structure forming technique, miniaturization of processing dimensions is required to improve the integration degree of a semiconductor integrated circuit.

  Therefore, in photolithography, which is a representative technique for microfabrication, the need to increase the resolution and control the micro dimensions with high precision has increased, and so far, attempts have been made to increase the resolution by shortening the exposure wavelength. Has been. To date, a resolution of a minimum line width of 100 nm using an ArF laser, a resolution of several tens of nanometers using electron beams and X-rays, a so-called nanostructure formation technology has also been achieved, and the practical application of these technologies has been studied. Progressing.

  However, since these techniques improve the resolution by shortening the exposure wavelength, the initial cost of the exposure apparatus itself and the increase in the price of the mask to be used are unavoidable, and as a result, the cost is very disadvantageous. . In addition, there is a problem that the irradiation spot diameter is small and the productivity is low to form a fine structure with a large area.

  In recent years, therefore, imprint lithography has been proposed by Chou et al. As a technique for easily shaping a fine structure (see Non-Patent Document 1). Imprint lithography is a technique for transferring a pattern on a mold to a resin, and there are two types of methods, thermal and optical.

  The former thermal method is a technique for transferring a thermoplastic resin by pressing a mold having a concavo-convex pattern onto the surface of the thermoplastic resin after heating the thermoplastic resin to a glass transition temperature Tg or higher and lower than a melting point Tm. The latter optical method is a technique in which a pattern on a mold is transferred to each resin by irradiating and curing the light while pressing the mold against the photocurable resin.

  Although these techniques require initial costs for mold production, many microstructures can be replicated from a single mold, resulting in the formation of a microstructure that is cheaper than photolithography. Technology.

  On the other hand, not only miniaturization of patterns and high precision, but also advanced structural control is becoming important, and high-performance materials with new functions can be obtained by arranging functional materials with high precision in arbitrary locations. Development is progressing.

  For example, an optical functional sheet in which a light condensing function is expressed by alternately arranging a phase having light diffusibility (light diffusing phase) and a substantially transparent phase (transparent phase) (see, for example, Patent Documents 1 and 2) ), A transparent sheet material having electromagnetic shielding properties by arranging conductive materials in a pattern on a substrate (see Patent Document 3), or a sheet having polarization separation characteristics (see Patent Document 4), etc. Has been proposed.

  In the development of these high-performance materials, in order to arrange the functional materials with high precision in arbitrary locations, until now, one phase was formed first by, for example, lithography or etching, and then functioned in the gaps between the phases. Usually, a method such as filling a material is adopted.

  However, these methods are limited by materials and have to go through many complicated processes, resulting in low productivity and difficult industrial realization.

In addition, when optical imprint lithography is used, it is possible to arrange the functional material in a pattern by mold transfer by mixing the functional material with the photocurable material, but the resin that can be used However, the material used is limited, for example, there is a condition that only a photo-curable material can be mixed and a material that can be mixed also transmits light having a wavelength that the photo-curable material is sensitive to.
"Appl. Phys. Lett.", Chou et al., USA, American Physical Society, 1995, Vol. 67, No. 21, p. 3314 JP 2002-214411 A (page 3-24) JP 2002-277613 (page 2-5) JP 2003-103696 A (page 4-15) JP 2001-74935 A (all pages)

  An object of the present invention is to overcome the problems of the prior art as described above, and to easily and inexpensively pattern a functional material on a substrate, a pattern forming sheet, and an optical function formed using the method The purpose is to provide sex sheets.

The present invention employs the following means in order to achieve this object.
That is, the pattern forming method of the present invention is a pattern forming method in which a surface layer is patterned by transferring a mold to a laminate in which a surface layer is formed on one side or both sides of the substrate layer. The pattern forming method is characterized by satisfying the following requirements (A) and (B).

(A) The surface layer contains at least metal fine particles or metal-coated fine particles whose surface is coated with a metal.

(B) The mold has a surface shape in which the mold convex part height H is larger than the surface layer film thickness L and the mold concave sectional area S2 is larger than the surface layer sectional area S1. The surface layer is penetrated by the convex part of the mold pressed against.

  Further, the pattern forming method of the present invention more specifically preferably has one of the following specific structures (1) to (6).

(1) When performing mold transfer, it includes at least a step of heating the mold and / or the laminate to transfer the mold surface shape to the laminate.

(2) The ratio of the average particle diameter R of the fine particles in the surface layer to the width w2 of the mold recess is R / w2 of 0.5 or less.

(3) The average particle diameter R of the fine particles in the surface layer is 0.001 to 50 μm.
(4) The content of fine particles in the surface layer is 80% by weight or more.

(5) The average particle diameter R of the fine particles in the surface layer is 100 nm or less.
(6) A step of heat-treating a pattern obtained by mold transfer after heating the mold and / or the laminate and transferring the mold surface shape to the laminate.

  The optical functional sheet (1) of the present invention is an optical functional sheet in which a pattern in which a surface layer containing at least metal fine particles or metal-coated fine particles is arranged is formed on the substrate surface by the pattern forming method described above. Thus, it has a polarization separation function of transmitting a polarization component in a certain uniaxial direction and reflecting or absorbing a polarization component perpendicular to the polarization component.

  Further, the optical functional sheet (2) of the present invention is an optical in which a pattern in which a surface layer containing at least metal fine particles or metal-coated fine particles is arranged on the surface of the substrate is formed by any of the pattern forming methods described above. An optical functional sheet, which is a functional sheet and has a function of reflecting or absorbing electromagnetic waves.

The pattern forming sheet of the present invention has the following feature (7).
(7) A laminate comprising a base material layer and a surface layer formed on one or both sides of the base material layer, wherein the surface layer has metal fine particles having an average particle size R of at least 0.001 to 50 μm, or the surface 80% by weight or more of metal-coated fine particles coated with metal.

 In addition, the pattern forming sheet of the present invention more specifically preferably has the following specific configuration (8).

(8) The average particle diameter R of the metal fine particles or metal-coated fine particles in the surface layer is 100 nm or less.

  According to the present invention, it is possible to form a functional material in a pattern on a substrate by a simple and inexpensive method without going through complicated steps. Moreover, the pattern formation sheet suitable for the formation can be provided.

  Furthermore, by using the method of the present invention, an optical functional sheet having a pattern in which a surface layer containing at least metal fine particles or metal-coated fine particles is arranged on the substrate surface can be easily formed.

  The present inventors have intensively studied a method for forming a functional material in a pattern on a substrate and a pattern forming sheet, and a mold having an uneven shape on a surface layer formed on one side or both sides of the substrate. The inventors have found that the above-described problems can be solved by pressing and penetrating the surface layer, and the present invention has been achieved.

  That is, the pattern forming method of the present invention is a pattern forming method in which a surface layer is patterned by transferring a mold to a laminate comprising a base layer and a surface layer formed on one side or both sides of the base layer. Thus, the following requirements (A) and (B) are satisfied.

That is,
(A) The surface layer contains at least metal fine particles or metal-coated fine particles whose surface is coated with a metal.
(B) The mold has a surface shape in which the mold convex part height H is larger than the surface layer film thickness L and the mold concave sectional area S2 is larger than the surface layer sectional area S1. The surface layer is penetrated by the convex part of the mold pressed against.
It is.

The principle of the pattern forming method of the present invention will be described with reference to FIG.
The laminated body 1 in which the surface layer 11 is laminated on the base material 12 and / or the mold 2 having the concavo-convex shape in which the pattern shape to be transferred is inverted is heated (FIG. 1A), and the laminated body 1 and the gold The mold 2 is approached, pressed as it is at a predetermined pressure, and held for a predetermined time (FIG. 1 (b)). Here, the heating of the laminate and / or the mold may be performed as necessary, and is not essential.

  Next, the temperature is lowered while maintaining the pressed state. Finally, the press pressure is released and the molded product 3 is released from the mold 2 (FIG. 1 (c)).

  The pattern forming method of the present invention is characterized in that the surface layer 11 provided on the surface layer of the laminate 1 is penetrated by the intrusion of the mold convex portion 21 at the time of pressing, and the pattern 5 is formed on the substrate portion 4. .

  Here, the definition of “penetration” in the present invention will be described with reference to FIG. In the present invention, “penetration” means that the surface layer 11 is torn at the intrusion portion of the mold convex portion 21 to form the pattern 5 on the base portion 4 as shown in FIG. However, the surface layer 11 is connected to the intrusion portion of the mold convex portion 21 without being partially or totally broken, and the pattern 5 is connected on the base portion 4 as shown in FIGS. If they are not functionally connected, they are regarded as “penetration” in the present invention. In addition, as an example of “penetration” that is not functionally connected, for example, when a conductive pattern is formed using a conductive material as the surface layer 11, the conductivity of the connecting portion is negligible compared to the pattern portion. The case where it is small and substantially only a pattern part conduct | electrically_connects is mentioned.

  In the pattern forming method of the present invention, in order to penetrate the surface layer 11 by intrusion of the mold convex portion, the height H of the mold convex portion 21 of the mold 2 is set to the film of the surface layer 11 of the laminate 1. It must be greater than the thickness L.

The film thickness L of the surface layer 11 referred to here is a method in which the cross section of the laminate 1 is observed in a direction z perpendicular to the film surface direction x of the laminate 1 as shown in FIG. A line l ₂ is drawn to indicate the distance that the normal l ₂ crosses the surface layer 11. When the film thickness L of the surface layer 11 varies depending on the position, the film thickness L of the surface layer 11 is set to the maximum value. Further, the height H of the mold convex portion 21 means that the mold protrudes through the lowest point of the mold concave portion 22 when the cross section of the mold 2 is observed as shown in FIG. A line l _{3 in the} surface direction is drawn and expressed by the shortest distance from the apex of the mold convex portion 21 to the line. In addition, when the height H of the metal mold | die convex part 21 changes with positions, it is set as the height H of the metal mold | die convex part 21 with the minimum value. When the height H of the mold convex portion 21 is smaller than the film thickness L of the surface layer 11, the mold convex portion 22 cannot reach the base material layer 12 and cannot penetrate therethrough.

  The mold 2 in the pattern forming method of the present invention is characterized in that the cross-sectional area S2 of the mold recess 22 is larger than the cross-sectional area S1 of the surface layer 11. The cross-sectional area S2 of the mold recess 22 referred to here is a mold recess area formed between adjacent mold protrusions when the cross section of the mold 2 is observed. The cross-sectional area S1 is a value given by the repetition unit (pitch) W × film thickness L of the adjacent mold convex portion. The pitch is represented by the sum of the width w1 of the mold convex portion 21 and the width w2 of the mold concave portion. When the pitch length unit varies depending on the position, the pitch is represented by the minimum value. When the cross-sectional area S2 of the mold recess 22 varies depending on the position, the cross-sectional area S2 of the mold recess 22 is set with the minimum value.

  When receiving the intrusion of the mold convex portion 21, the surface layer 11 is excluded by the mold convex portion 21 and guided to the mold concave portion 22 to penetrate therethrough. However, when the cross-sectional area S2 of the mold recess 22 is smaller than the cross-sectional area S1 of the surface layer 11, it is not possible to introduce all of the surface layer 11 excluded by the intrusion of the mold protrusion 21 into the mold recess 22. Therefore, it cannot reach the base material layer 12 and cannot penetrate. In the present invention, it is possible to penetrate the surface layer 11 by increasing the cross-sectional area S2 of the mold recess 22 from the cross-sectional area S1 of the surface layer 11, and as a result, the surface layer is patterned on the substrate. Can be formed.

  That is, in the mold 2 in the pattern forming method of the present invention, the height H of the mold protrusion is larger than the film thickness L of the surface layer 11 of the laminate, and the cross-sectional area S2 of the mold recess is the surface layer 11. By making it larger than the cross-sectional area S1, the surface layer 11 can be penetrated by the mold convex portion 21, and as a result, the surface layer can be formed in a pattern on the substrate.

  4A to 4G illustrate cross-sectional views of the mold 2 that is preferably used in the pattern forming method of the present invention. FIG. 4 illustrates a preferable shape of the mold protrusion. As a preferable shape of the convex portion 21 of the mold, a rectangular shape (FIG. 4 (a)), a trapezoid shape (FIG. 4 (b)), a triangle shape (FIG. 4 (c)), or a modified shape thereof (FIG. (E), (f), (g)), and mixtures thereof may be mentioned, but other shapes can also be used.

  In addition, between adjacent mold convex portions, when a flat portion is formed as shown in FIGS. 4A to 4F, or without forming a flat portion as shown in FIG. 4G. Any of continuous connection may be used. As for the shape of the mold recess, a shape such as a rectangle, a trapezoid, a triangle, a bell shape, or a shape obtained by deforming them can be preferably used as in the case of the mold protrusion.

  5 and 6 are schematic views illustrating preferred shapes and arrangements of the mold convex portions 21 and the mold concave portions 22 in a cross section when the mold 2 is cut in parallel with the surface thereof. As shown in FIGS. 5 and 6, the shape of the mold convex portion 21 and the mold concave portion 22 is preferably a shape selected from a linear shape, a substantially triangular shape, a substantially rectangular shape, a substantially hexagonal shape, a circle, an ellipse, and the like. it can. 5 (a) to 5 (c), the mold convex portion 21 and the mold concave portion 22 are striped, and FIGS. 5 (d) and 5 (e) are the mold concave portion 22 is circular, triangular, and FIG. ) Is a square shape of the mold recesses 22 (the mold projections 21 are in a lattice pattern), FIG. 5G is a staggered grid pattern consisting of the mold projections 21 and the mold recesses 22, and FIG. 6 (a) to 6 (d) show the case where the mold convex part 21 and the mold concave part 22 in FIGS. 5 (d), (e), (f), and (h) are inverted, respectively. , Respectively. The mold convex part 21 and the mold concave part 22 may be aligned as shown in the figure, may be arranged at random, or may have different shapes.

  Here, the width of the mold convex portion 21 and the width of the mold concave portion 22 are represented by the lengths w1 and w2, respectively, in the case of FIG. In addition, when the length unit changes with height positions like FIG.4 (b) etc., it represents with an average value, respectively. Note that the width w1 of the mold convex portion 21 is measured in the direction in which the unit length is short in the case of the stripe pattern shown in FIGS. In the case of FIGS. 5D to 5H, the shortest unit length is defined as the width w1 of the mold protrusion. Further, when the mold convex portion 21 is circular as shown in FIG. 6 (a), the diameter thereof is indicated. When the mold convex portion 21 is elliptical, its short diameter is indicated. As shown in FIGS. In the case of a polygon, the diameter of the inscribed circle may be the width w1 of the mold convex portion 21. The same definition applies to the width w2 of the mold recess.

  In the cross section in the plane direction of the mold 2, the ratio of the area S <b> 2 ′ of the mold protrusion 21 and the area S <b> 2 ″ of the mold recess 12 is arbitrary.

  As the material of the mold, various materials such as glass, silicon, stainless steel (SUS), nickel (Ni) can be used, and although not particularly limited, from the viewpoint of mold workability, silicon, glass, From the viewpoint of releasability and durability, metal materials such as stainless steel (SUS) and nickel (Ni) are preferable.

  The above-mentioned material may be used as it is for the mold, but the surface of the mold 2 is treated with a surface treatment agent so that the molded product can be easily released after the mold is transferred, thereby imparting easy lubricity. Is preferred. The contact angle of the surface layer of the mold 2 after the surface treatment is preferably 80 ° or more, more preferably 100 ° or more.

  The surface treatment method of the mold includes a method of chemically bonding the surface treatment agent to the mold surface (chemical adsorption method), a method of physically adsorbing the surface treatment agent to the mold surface (physical adsorption method), etc. Can be used. Among these, the surface treatment is preferably performed by a chemical adsorption method from the viewpoint of repeated durability of the surface treatment effect and prevention of contamination of the molded product.

  Preferable examples of the surface treatment agent used in the chemical adsorption method include a fluorine-based silane coupling agent. As a surface treatment method using this, first, gold is obtained by ultrasonic treatment in an organic solvent (acetone, ethanol, etc.) or boiling in a solution of an acid such as sulfuric acid or a peroxide such as hydrogen peroxide. After cleaning the mold surface, use a method in which a fluorine-based silane coupling agent is dissolved in a fluorine-based solvent (wet method) or a method in which vacuum deposition is performed to deposit on the mold surface (dry method). can do. In the case of a wet method, it is also preferable to heat the solution during immersion. It is also preferable to heat the solution during immersion. Moreover, it is also preferable to heat-process after immersion.

  Here, the laminate 1 in the pattern forming method of the present invention is obtained by laminating the surface layer 11 on the surface of the base material layer 12, and the surface layer 11 is at least metal fine particles or the surface is coated with metal. It contains fine particles (hereinafter referred to as metal-coated fine particles).

  By using metal fine particles or metal-coated fine particles, a pattern in which a surface layer containing at least metal fine particles or metal-coated fine particles is arranged on the surface of the base material layer 12 can be formed. In addition, a pattern in which metals are arranged on a substrate can be formed by heat-treating a pattern obtained by mold transfer so that metal fine particles or metal-coated fine particles are fused.

  As the material of the metal fine particles, for example, gold, silver, copper, platinum, palladium, rhenium, vanadium, osmium, cobalt, iron, zinc, ruthenium, praseodymium, chromium, nickel, aluminum, tin, zinc, titanium, tantalum, zirconium, Examples include various metals such as antimony, indium, yttrium, and lanthanum. Metal-coated fine particles include zinc oxide, titanium oxide, cesium oxide, antimony oxide, tin oxide, indium tin oxide, yttrium oxide, lanthanum oxide, zirconium oxide, aluminum oxide, silicon oxide and other metal oxides, fluoride Inorganic fine particles such as metal fluorides such as lithium, magnesium fluoride, aluminum fluoride, cryolite, metal phosphates such as calcium phosphate, carbonates such as calcium carbonate, sulfates such as barium sulfate, talc and kaolin These are fine particles in which the surfaces of organic fine particles such as crosslinked styrene and crosslinked acryl are coated with the above-mentioned various metals.

  The metal-coated fine particles may be coated on the entire surface of the fine particles, or may be partially coated, either of which may be used. The shape of the fine particles (hereinafter, the metal fine particles and the metal-coated fine particles may be collectively referred to as “fine particles” or “metal fine particles”) is not particularly limited, and may be a true sphere, a spheroid, A flat shape, a bead shape, a plate shape, a needle shape, or the like can be preferably used. The fine particles 14 may be composed of a single metal element, or may be composed of a plurality of metal element elements, or a metal element and a non-metal element. Further, two or more kinds of the above-mentioned metal fine particles or metal-coated fine particles may be used, and furthermore, metal fine particles and metal-coated fine particles may be used in combination. In addition to the metal fine particles, fine particles made of an organometallic compound such as fatty acid silver which can be easily reduced to a metal element by performing a treatment such as heating can be suitably used.

  Moreover, in the pattern formation method of this invention, it is preferable that ratio R / w2 of the average particle diameter R of the microparticles | fine-particles 14 in the surface layer 11 and the width | variety w2 of a metal mold | die recessed part is 0.5 or less. More preferably, it is 0.4 or less, most preferably 0.3 or less. If the ratio R / w2 between the average particle diameter R of the fine particles 14 in the surface layer 11 and the width w2 of the mold concave portion is larger than this range, the surface layer containing the fine particles 14 even if the mold convex portion 21 is invaded. 11 becomes difficult to introduce into the mold recess 22 and cannot penetrate. In the pattern forming method of the present invention, by making the ratio R / w2 of the average particle diameter R of the fine particles 14 and the width w2 of the mold recesses to be 1/2 or less, the surface layer 11 can be penetrated. As a result, the surface layer can be formed in a pattern on the substrate.

  In the pattern forming method of the present invention, 0.001 to 50 μm is preferably used as the average particle size R of the fine particles 14. Here, the average particle diameter R of the fine particles 14 is the average particle diameter R of the fine particles 14 observed in the cross-sectional observation image of the surface layer 11. Indicates the arithmetic average value of the major axis diameter and minor axis diameter during planar projection. In the case of a co-continuous structure, the average interphase distance is the average particle diameter R of the fine particles. These are values measured by an electron microscope.

  Here, in the pattern forming method of the present invention, the metal fine particles or the metal-coated fine particles can be fused by performing a heat treatment on the pattern obtained by the mold transfer.

  In this case, the heat treatment temperature is preferably set to a temperature equal to or higher than the fusion start temperature of the fine particles 14. Since the fusion start temperature of the fine particles 14 increases as the average particle size R of the fine particles 14 increases, the average particle size R of the fine particles 14 to be used is preferably 100 nm or less. More preferably, it is 75 nm or less, and most preferably 50 nm or less. If the average particle size R of the fine particles 14 is larger than this range, the fusion start temperature becomes too high, the heat treatment temperature for fusion becomes too high, and the base material layer is greatly deformed in the heat treatment step. It is not preferable because there is. In the present invention, by setting the average particle size R of the fine particles 14 to 100 nm or less, the fine particles can be fused together by low-temperature heat treatment. A preferable lower limit value of the average particle diameter R of the fine particles 14 is 1 nm, and more preferably 2 nm.

  In the pattern forming method of the present invention, the content of the fine particles 14 in the surface layer 11 is preferably 80% by weight or more. More preferably, it is 85 weight% or more, Most preferably, it is 90 weight% or more. If it is less than this range, even if metal fine particles or metal-coated fine particles are arranged on the surface, the function as an arrangement pattern of metal fine particles may not be exhibited, or the pattern obtained by mold transfer is heat-treated. An attempt to fuse metal fine particles into a metal pattern is not preferable because conductivity may be insufficient and a function as a metal pattern may not be exhibited. In the pattern forming method of the present invention, the function of the formed pattern can be sufficiently obtained by setting the content of the metal fine particles in the above range. In addition, the upper limit with preferable content of a metal microparticle is 99.9 weight%, More preferably, it is 99 weight%.

  Further, the surface layer 11 may be added with a resin 13 serving as a matrix for the purpose of imparting adhesiveness to the base material layer 12, improving the dispersibility of the fine particles 14, and preventing slipping. The matrix 13 that can be added is not particularly limited, and a thermoplastic resin, a thermosetting resin, a photocurable resin, a photodegradable resin, or the like can be suitably used.

  The material of the base material layer 12 of the laminate 1 in the pattern forming method of the present invention is preferably composed mainly of a resin having thermoplasticity. As a preferred specific example of a thermoplastic resin that can be the main component, Polyester resins such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polypropylene terephthalate, polybutylene terephthalate, polyolefin resins such as polyethylene, polystyrene, polypropylene, polyisobutylene, polybutene, polymethylpentene, polyamide resins, polyimide resins , Polyether resins, polyester amide resins, polyether ester resins, acrylic resins such as PMMA, polyurethane resins, polycarbonate resins, polyvinyl chloride resins, and copolymers thereof And the like mixtures thereof. Of these, polyester resins, polyolefin resins, polyamide resins, acrylic resins, or mixtures thereof are particularly preferred because of the variety of monomer types to be copolymerized and the ease of controlling material properties. It is preferable that the thermoplastic resin as the main component occupies 50% by weight or more of all components. Moreover, it is also preferable that the above-mentioned thermoplastic resin has both photocurability and thermosetting properties as well as thermoplasticity.

  The glass transition temperature Tg2 before and after the pattern formation of the base material layer 12 of the laminate 1 in the pattern forming method of the present invention is preferably 30 to 250 ° C, more preferably 40 to 230 ° C, and most preferably 50. It is the range of -200 degreeC. When the glass transition temperature Tg2 is less than this range, the handling property of the laminate 1 may be deteriorated before molding, and the heat resistance of the pattern is lowered after molding, and the shape may change with time. If the temperature exceeds this range, the molding temperature is high and energy is inefficient, and in the molding process (heating / cooling cycle), the volume variation of the laminate 1 becomes large and the laminate 1 bites into the mold 2. In this case, it is not preferable because the mold cannot be released from the mold, and even if the mold can be released, the accuracy of the pattern is lowered, or the pattern is partially missing, resulting in a defect. In the pattern formation method of this invention, favorable precision and mold release property can be obtained by making the glass transition temperature Tg2 of the base material layer 12 of the laminated body 1 into this range. The glass transition temperature Tg1 before and after the pattern formation of the matrix 13 of the surface layer 11 of the laminate 1 in the pattern formation method of the present invention is not particularly limited, but preferably Tg2 ≧ Tg1-20 ° C. It is good in terms of ease of penetration.

  In addition to the thermoplastic resin as the main component, the base material layer 12 is also preferably added with a component that is cured by crosslinking by irradiation with electromagnetic waves or heat. When such a component is added, the mechanical strength and thermal stability of the formed pattern or substrate can be improved by crosslinking the formed pattern by electromagnetic wave irradiation or heat treatment.

  In the pattern forming method of the present invention, various functional materials such as dyes, pigments, electromagnetic wave absorbers, conductive materials, magnetic materials, liquid crystal materials, and light emitting materials may be added to the surface layer 11 in addition to the fine particles. . Furthermore, the above-described functional material may be added to the base material layer 12. Moreover, other various additives can be added to the surface layer 11 and the base material layer 12 within the range where the effects of the present invention are not lost. Examples of additives that can be added and blended include, for example, dispersants, antioxidants, weathering agents, antistatic agents, polymerization inhibitors, mold release agents, thickeners, pH adjusters, and salts. .

  As described above, the film thickness L of the surface layer 11 is not particularly limited as long as the height H of the mold convex portion 21 of the mold 2 is larger than the film thickness L of the surface layer 11 of the laminate 1. From the viewpoint of penetrability, it is preferably 0.01 to 200 μm, more preferably 0.01 to 150 μm, and still more preferably 0.01 to 100 μm.

  The thickness of the base material layer 12 is not particularly limited, but is preferably 5 μm to 2 mm, more preferably 10 μm to 1 mm, and still more preferably 15 μm to 800 μm, from the viewpoint of handleability as a sheet. However, as will be described later, the thickness of the base material layer 12 when other different materials are provided as a support layer in the laminate is not limited to the above range, and may be 0.01 to 5 μm.

  Further, as the base material layer 12, a resin layer (sheet) such as uniaxially or biaxially stretched polyethylene terephthalate may be used in order to improve the mechanical strength, heat resistance and ease of handling of the sheet itself. . In the case of using a biaxially stretched sheet such as polyethylene terephthalate, the thickness is preferably 20 to 500 μm, more preferably 30 to 300 μm, and most preferably 50 to 200 μm from the viewpoint of mechanical strength.

  The laminate 1 in the pattern forming method of the present invention comprises a base layer 12 and a surface layer 11 formed on one side or both sides of the base layer 12, and the surface layer 11 and the base layer 12 are These may be either a uniform single layer or a multilayer structure made of different materials.

  In addition, it is also preferable to provide another different material as a support layer in the laminate 1 used in the present invention.

  When using a support body layer, it becomes the structure laminated | stacked in order of the support body layer, the base material layer, and the surface layer. Examples of preferred support layers include film base materials such as polyester resin, polyolefin resin, and acrylic resin, and those obtained by stretching them uniaxially or biaxially, stainless steel, aluminum, aluminum alloy, iron, steel, titanium, silicon, etc. Examples include metal substrates and various substrates such as quartz glass, and inorganic substrates such as concrete. Especially when forming a translucent optical functional sheet, film substrates such as polyester resins, polyolefin resins, acrylic resins, and the like Those having a light transmission property such as glass uniaxially or biaxially or glass are preferably used. The thickness of the support layer is not particularly limited. In addition, the support layer may be subjected to a treatment such as a base preparation material or an undercoat material.

  As a manufacturing method of the laminated body 1 used for the pattern formation method of this invention, the composition which comprises the base material layer 12 and the composition which comprises the surface layer 11, for example are thrown into another two extruders, respectively. , A method of co-extrusion onto a cast drum cooled from the die and cooled into a sheet (co-extrusion method), a raw material of the surface layer 11 is put into an extruder into a base material layer 12 made of a single film A method of melt extrusion and lamination while extruding from a die (melt lamination method), a method in which the substrate 12 and the surface layer 11 are separately produced as a single film, and thermocompression bonded with a heated roll group (thermal lamination method), Other examples include a method (coating method) in which the composition constituting the surface layer 11 is dissolved or dispersed in a solvent and the solution or dispersion is applied onto the base material layer 12. Of these methods, the coating method is particularly preferably used when the fine particle content of the surface layer 11 is high or when fine particles having a low fusion start temperature are used. In the coating method, when it is necessary to dry and remove the solvent after coating, the drying temperature is preferably not higher than the fusion start temperature of the fine particles.

  Moreover, when providing the base material layer 12 on a support body layer, after forming the laminated body 1 by the above-mentioned method, it may be bonded together to a support body, and the composition which comprises the base material layer 12 is made into an extruder. Injecting, melting and laminating to the support layer while extruding from the die (melt laminating method), the base material 12 and the support layer are separately produced as single films, and thermocompression bonded with a heated roll group or the like The support is formed by a method (thermal laminating method), a method of dissolving or dispersing the composition constituting the substrate layer 12 in a solvent, and applying the solution or dispersion onto the substrate layer 12 (coating method). After laminating the layer and the base material layer 12, the surface layer 11 may be formed by the method described above.

  In the pattern forming method of the present invention, as shown in FIG. 1, a mold 2 having an uneven shape is pressed against the surface of a laminate 1 to transfer the mold surface shape, and the surface layer 11 is penetrated. In addition to the method of pressing a lithographic mold as shown in FIG. 1 (lithographic pressing method), roll-to-roll continuous forming using a roll-shaped mold is also a preferred method. Roll-to-roll continuous forming is superior to the lithographic press method in terms of productivity.

  In the pattern formation method of the present invention, it is preferable that at least one of the mold temperature T1 and the laminate temperature T2 at the time of press molding is equal to or higher than Tg1 of the matrix 13 contained in the surface layer 11. More preferably, both T1 and T2 satisfy the above range. When both T1 and T2 are less than this range, it may be difficult to penetrate the surface layer 11 even if a mold is pressed on the surface layer 11.

  In addition, it is more preferable that at least one of the mold temperature T1 and the laminate temperature T2 at the time of press molding is in the range of Tg2 to Tg2 + 50 ° C. of the base material 12. Moreover, it is more preferable that both T1 and T2 satisfy the above range. By making it within this range, the substrate 12 also follows the deformation, the penetrability is improved, and the shape of the mold can be accurately transferred. However, if this range is exceeded, the volume fluctuation of the molded product in the heating / cooling cycle will increase, and it will be impossible to release it by biting into the mold, and even if it can be released, the pattern will be deformed or partially It is not preferable for reasons such as lack of a pattern and a defect. In the pattern forming method of the present invention, by setting at least one of the mold temperature T1 or the laminate temperature T2 during press molding within this range, both good penetrability, accuracy, and releasability can be achieved. .

  Moreover, in the pattern formation method of this invention, although a press pressure is dependent on the surface layer 11 at the time of shaping | molding, the dynamic storage elastic modulus E 'of the base material 12, etc., 0.01-50 Mpa is preferable. More preferably, it is 0.5-30 MPa. If it is less than this range, the convex portion of the mold cannot sufficiently enter the surface layer 11, and it may be difficult to penetrate the surface layer 11. On the other hand, exceeding this range is not preferable because the required load increases and the load on the mold is repeatedly increased, resulting in a decrease in durability. By setting the pressing pressure within this range, good transferability can be obtained.

  The pressing pressure holding time depends on various conditions such as the value of the dynamic storage elastic modulus E ′ of the surface layer 11 and the base material 12 during molding, the molding pressure, the shape and thickness of the mold.

  In the pattern forming method of the present invention, the press pressure release temperature T3 is preferably lower than the molding temperature and within the temperature range of Tg2-20 ° C to Tg2 + 20 ° C. If it is less than this range, the deformation of the laminate 1 at the time of pressing remains as residual stress, which is not preferable because the thermal stability of the molded product may be lowered. Further, if it exceeds this range, the dynamic storage elastic modulus E ′ at the time of pressure release is low, and the molded body is in a state of fluidity, so that the pattern may be deformed and accuracy may be lowered. It is not preferable. In the pattern forming method of the present invention, by setting the press pressure release temperature T3 within this range, both good transferability and release properties can be achieved.

  Moreover, in the pattern formation method of this invention, it is preferable that mold release temperature T4 exists in the temperature range of normal temperature-T3 degreeC. Exceeding this range is not preferable because the pattern may be deformed and the accuracy is lowered. In the pattern forming method of the present invention, the mold can be released with good pattern accuracy by setting the temperature at the time of mold release to this range.

  Here, in the pattern forming method of the present invention, a metal pattern can be obtained by fusing the fine particles 14 by heat-treating the pattern obtained by mold transfer. In this case, as a method of fusing, a method of performing at least one of the mold temperature T1 at the time of the above-mentioned mold pressing or the temperature T2 of the laminated body 1 above the fusing start temperature of the fine particles, or fusing the fine particles after the pattern forming step. Either method of heat treatment above the deposition start temperature may be used. The former method in which at least one of the mold temperature T1 at the time of mold pressing or the temperature T2 of the laminated body 1 is set to be equal to or higher than the fusion start temperature of the fine particles is to simultaneously perform pattern formation and fine particle fusion by die transfer. As a result, the number of steps can be reduced, which is preferably performed. In order to further promote the fusion of metals, the latter method may be performed after the former method.

  7A to 7F schematically illustrate cross-sectional views of molded articles obtained by the pattern forming method described above. FIG. 7 shows an example in which the surface layer 11 is torn by the intrusion of the mold convex portion, and the surface layer 11 is formed in a pattern on the base portion 4. Preferred shapes of the pattern 5 of the surface layer 11 after molding include a rectangle (see FIG. 7 (a)), a trapezoid (see FIG. 7 (b)), a triangle (see FIG. 7 (c)), and a deformed form thereof. (See FIGS. 7 (d), (e), (f), (g)), and combinations of these, but other shapes can also be used. Moreover, between the adjacent molded product convex portions, when a flat portion is formed as shown in FIGS. 7A to 7F, or without being formed as shown in FIG. 7G. Any of continuous connection may be used. In addition, as for the shape of the concave portion of the molded product, similarly to the convex portion of the molded product, a shape such as a rectangle, a trapezoid, a triangle, a bell shape, or a deformed shape thereof can be preferably used.

  Moreover, when the structure of the surface layer 11 is seen in detail, the structures illustrated in FIGS. 2A to 2F are also preferably used. 2A to 2C show a state in which the surface layer 11 is broken at the intrusion portion of the mold convex portion, and FIGS. 2D to 2F show that the surface layer 11 is partially or entirely connected. However, FIG. 2 (a) and FIG. 2 (d) show the case where the entire convex part of the molded product is formed of a material constituting the surface layer. (B) and (e) show the case where the surface layer of the convex part of the molded product is covered with the surface layer 11, and FIGS. 2 (c) and 2 (f) show cases in the intermediate state.

  These structures shown in FIGS. 2A to 2F include the material of the surface layer 11, the thickness L, the cross-sectional area S1, the dynamic storage elastic modulus E1 ′, the material of the base material layer 12, and the dynamic storage elasticity. It can be formed by appropriately changing the rate E2 ′, the height H of the mold convex portion 21, the cross-sectional area S2 of the mold concave portion, and the like.

  8A to 8H are cross-sectional views schematically showing the arrangement of the patterns 5 in the cross section when the molded product obtained by the pattern forming method of the present invention is cut in parallel to the film surface. is there. As shown in FIGS. 8A to 8H, the shape of the pattern 5 may have a shape selected from a linear shape, a substantially triangular shape, a substantially rectangular shape, a substantially hexagonal shape, a circle, an ellipse, and the like. 8A to 8C show a case where the pattern 5 has a stripe shape, FIG. 8D shows a case where the pattern 5 has a circular cross section, FIG. 8E shows a case where the pattern 5 has a triangular shape, FIG. (F)-(g) illustrates the case where it is a square shape, and FIG. 8 (h) illustrates the case where it is a hexagonal shape. The patterns 5 may be aligned as shown in the figure, may be arranged randomly, or different shapes may be mixed. Moreover, as shown in FIGS. 9A to 9D, the shape of the portion where the pattern 5 does not exist may have a shape selected from a substantially triangular shape, a substantially rectangular shape, a substantially hexagonal shape, a circle, an ellipse, and the like. .

  In the cross section in the surface direction of the molded product, the ratio of the area S3 'of the molded product convex portion to the area S3 "of the molded product concave portion is arbitrary.

  Further, the base 4 of the molded product obtained by the pattern forming method of the present invention includes a flat portion 41 and a convex base portion 42. The height h2 ′ of the base portion 42 is arbitrary, but the thickness l ′ of the flat portion 41 is preferably 20 μm to 2 mm, more preferably 30 μm to 1 mm, and even more preferably 50 to 500 μm from the viewpoint of mechanical strength. It is. However, when a support layer is provided under the base portion 4, the thickness l 'of the flat portion 41 is not particularly limited and may be 20 μm or less.

  The molded product obtained by the pattern forming method of the present invention is made of various metals such as electrolytic plating, electroless plating, vapor deposition, sputtering, etc. on the formed pattern 5 in order to enhance its performance or to develop further functions. Processing may be performed. It does not specifically limit as a metal seed | species to be used, Various metal seed | species etc. are used suitably. When vapor deposition or sputtering is performed, if vapor deposition or sputtering is performed on the film surface of the molded product from the normal direction, a metal layer may be formed on the entire surface, and the functionality as a pattern may be greatly reduced. Therefore, in order to selectively perform vapor deposition or sputtering only on the pattern 5, the vapor deposition or sputtering is performed from the normal direction to the film surface of the molded product, in an oblique direction, for example, in the case of a stripe, perpendicular to the arrangement. It is preferable to perform sputtering.

  In the molded product obtained by the pattern forming method of the present invention, the surface of the formed pattern 5 or the pattern 5 is formed in order to increase the mechanical strength of the formed pattern 5 or to impart friction resistance to the surface. A protective film made of a transparent resin, a metal oxide film, or the like may be formed on the entire surface, or a recess between the formed patterns 5 may be filled with the transparent resin. The transparent resin that can be used is not particularly limited, and a thermoplastic resin, a thermosetting resin, a photocurable resin, and the like can be suitably used. Further, the metal oxide that can be used is not particularly limited as long as it is transparent. In addition, another film such as a protective film is preferably bonded to the surface of the molded product obtained by the pattern forming method of the present invention.

  Moreover, arbitrary layers, such as an antistatic layer, an antireflection layer, a hard-coat layer, can be formed in the unshaped surface side of the pattern of the molded article obtained by the pattern formation method of this invention. Moreover, it can also be set as the function integrated high performance sheet | seat which has many functions by bonding with the base material etc. which have another function.

  The molded product obtained by the pattern forming method of the present invention can be used in various applications such as a display member, a semiconductor integrated material, a design member, an optical circuit, an optical connector member, and a biochip by appropriately selecting the material constituting the pattern. It can be deployed. In particular, when a translucent base material is used as the base material layer 12, sheets having various translucent optical functionalities can be formed.

  Examples thereof include (1) a reflective polarizing plate and (2) an electromagnetic wave shielding film. Details of these examples are given below.

(1) Reflective Polarizing Plate The optical functional sheet (1) obtained by the pattern forming method of the present invention transmits a certain uniaxial polarization component and reflects or absorbs a polarization component perpendicular to the polarization component. It has a polarization separation function.

  As a specific shape of the optical functional sheet (1) of the present invention, a metal layer 150 is formed in a pattern on the base 140 as shown in FIG. FIG. 10 shows an example in which the surface layer 11 is torn by the intrusion of the mold convex portion, and the metal layer 150 is formed in a pattern on the base portion 140. However, the present invention is not limited to this. Instead, the structures illustrated in FIGS. 11A to 11F are also preferably used. 11A to 11C show a state in which the surface layer 11 is broken at the intrusion portion of the mold convex portion, and FIGS. 11D to 11F show that the surface layer 11 is partially or entirely connected. However, FIG. 11 (a) and FIG. 11 (d) show a case where the entire convex portion is formed of a material constituting the surface layer, as shown in FIG. 11 (b). ) And (e) show the case where the surface layer of the convex portion is covered with the surface layer 11, and FIGS. 11 (c) and 11 (f) show cases in the intermediate state. These structures shown in FIGS. 11A to 11G include the material of the surface layer 11, the thickness L, the cross-sectional area S1, the dynamic storage elastic modulus E1 ′, the material of the base material layer 12, and the dynamic storage elasticity. The ratio E2 ′ can be formed by appropriately changing the height H of the mold convex portion 21, the cross-sectional area S2 of the mold concave portion, and the like.

  In the optical functional sheet (1) of the present invention, the preferred shape of the metal layer 150 is a rectangle (see FIG. 10A), a trapezoid (see FIG. 10B), or a triangle (see FIG. 10C). These are deformed (see FIGS. 10 (d) to (g)) and their combined shapes, but are not limited to these, and if linear irregularities are formed in the plane. It can be preferably used. Further, between adjacent patterns, when flat portions are formed as shown in FIGS. 10A to 10F, or continuously without forming flat portions as shown in FIG. 10G. Either of them may be used. Shapes other than these can also be used, and arbitrary polarization separation characteristics can be obtained by appropriately selecting the shape.

  FIG. 12 is a perspective view schematically showing the pattern shape of the optical functional sheet (1) of the present invention. In the plane, the metal layer 150 is formed on the base 140 in a stripe shape. Each stripe pattern is preferably formed in parallel. Each stripe pattern is preferably a straight line, but may be a broken line instead of a continuous straight line. Moreover, it does not need to be completely straight.

  That is, the optical functional sheet (1) of the present invention has a structure in which thin metal layer lines 150 are arranged in parallel on the base material 140 or the uneven surface side of the base material 140 having periodic stripe-shaped unevenness. In this structure, the metal layer 150 is formed. In addition, the period of unevenness of the metal layer line 150 or the metal layer 150 of the optical functional sheet (1) of the present invention is made shorter than the wavelength region of the light to be applied, so that uniform optical anisotropy in the wavelength region is achieved. It can be regarded as a sex structure. For this reason, optical anisotropy derived from structural anisotropy in a direction perpendicular to the direction parallel to the longitudinal direction of the stripe pattern appears. Thereby, the polarization component parallel to the longitudinal direction of the stripe pattern is reflected, and the perpendicular polarization component is transmitted, thereby functioning as a reflective polarizing plate.

Here, the polarization separation characteristic is expressed using the polarization degree P. The degree of polarization P is determined by overlapping the glass polarizing filter (manufactured by Edmund Optics Japan Co., Ltd.) and the side on which the metal layer 150 of the optical functional sheet (1) is formed. ) Is installed in a spectrophotometer U-3410 (manufactured by Hitachi, Ltd.), and the 90 ° optical functional sheet (1) from the position of the maximum transmittance Tmax and the maximum transmittance at each wavelength from the position. The transmittance (minimum transmittance) Tmin when rotated is measured, and the obtained value is used to obtain the polarization degree P = ((Tmax−Tmin) / (Tmax + Tmin)) ^0.5 . In addition, in the optical functional sheet (1) of the present invention, the degree of polarization Pc at the central wavelength in the wavelength region of the light to be applied is preferably 0.4 or more, more preferably 0.6 or more. A preferable upper limit of the degree of polarization Pc is 1.

  The optical functional sheet (1) of the present invention can be selected in any wavelength region without any special restrictions on the applicable wavelength region by appropriately selecting its shape (pitch, aperture ratio, width, aspect ratio, etc.). An optical functional sheet having reflective polarization separation characteristics can be obtained. Hereinafter, in particular, a reflective polarizing plate having an applicable wavelength region in the visible light region (400 to 800 nm) will be described in detail.

  In the optical functional sheet (1) of the present invention, the repeating unit (pitch) p1 ′ (= w11 ′ + w12 ′) of the metal layer line 150 or the unevenness of the metal layer 150 is preferably in the range of 50 to 400 nm, More preferably, it is 50-350 nm, Most preferably, it is 50-300 nm. If the pitch p1 'exceeds this range, the degree of polarization P in the short wavelength region is lowered, and particularly in the visible light region, the decrease in the degree of polarization P is not preferable. Further, if the pitch p1 ′ is less than this range, even if molding is difficult, or even if molding is possible, the physical strength of the metal layer 150 may be extremely reduced and easily collapsed by an external force. In addition, the metal layer 150 loses its metallic properties and does not perform its function, which is not preferable because it loses its function as a reflective polarizing plate. In the optical functional sheet (1) of the present invention, by setting the pitch p1 'to the above range, a high degree of polarization P can be obtained in the entire visible light region while maintaining the physical strength.

  In the optical functional sheet (1) of the present invention, the width w11 'of the metal layer 150 is preferably 20 to 380 nm, more preferably 20 to 300 nm, and most preferably 20 to 250 nm. If the width w11 ′ of the metal layer 150 is smaller than this range, it becomes difficult to form or even if the metal layer 150 can be formed, the physical strength of the metal layer is extremely reduced and easily collapses due to external force. In addition, the metal layer 150 loses its metallic properties and does not perform its function, and the function as a reflective polarizing plate may be lost (decrease in reflectance and degree of polarization). On the other hand, when the width w11 'is larger than this range, the aperture ratio is lowered, and the light transmittance is lowered, which is not preferable. In the optical functional sheet (1) of the present invention, by setting the width w11 ′ of the metal layer 150 in the above range, high transmittance, reflectance, and degree of polarization in the visible light region while maintaining physical strength. Can be obtained.

  In the optical functional sheet (1) of the present invention, the height h11 ′ of the metal layer 150 formed on the substrate 140 is preferably 10 to 400 nm, more preferably 20 to 300 nm, and most preferably. 30-300 nm. If the height h11 'of the metal layer 150 is less than this range, the degree of polarization decreases, which is not preferable. Further, if the height h11 'exceeds this range, the polarization characteristic depends on the incident angle of light, which is not preferable. In the optical functional sheet (1) of the present invention, by setting the height h11 'of the metal layer 150 within the above range, high polarization characteristics can be obtained over a wide viewing angle region.

  In the optical functional sheet (1) of the present invention, the ratio of the height h11 ′ of the metal layer 150 formed on the substrate 140 to the width w12 ′ of the recess (h11 ′ / w12 ′, hereinafter referred to as aspect ratio) is. , Preferably in the range of 0.5-5. If the aspect ratio h11 '/ w12' is less than this range, it is not preferable because sufficient polarization characteristics cannot be obtained. On the other hand, if it exceeds this range, molding becomes difficult, and the convex portions meander and uneven polarization characteristics in the surface may appear. In the optical functional sheet (1) of the present invention, by setting the aspect ratio h11 '/ w12' to the above range, a uniform and high degree of polarization can be obtained in the plane.

  In addition, the base 140 of the optical functional sheet (1) of the present invention includes a flat portion 141 and a convex base portion 142. The height h12 ′ of the base portion 142 is arbitrary, but the thickness l1 ′ of the flat portion 141 is preferably 20 μm to 1 mm, more preferably 30 μm to 500 μm from the viewpoint of mechanical strength and reduction in thickness. More preferably, it is 50-300 micrometers. However, when a support layer is provided under the base portion 140, the thickness l1 'of the flat portion 141 is not particularly limited and may be 20 μm or less.

  The optical functional sheet (1) of the present invention can be selected in any wavelength region without any special restrictions on the applicable wavelength region by appropriately selecting its shape (pitch, aperture ratio, width, aspect ratio, etc.). An optical functional sheet having reflective polarization characteristics can be obtained. In particular, by forming with the above-mentioned dimensions, it is possible to obtain a reflective polarizing plate that exhibits polarization characteristics in the visible light region, that is, in the wavelength region of approximately 400 to 800 nm.

  The optical functional sheet (1) of the present invention is characterized by having a polarization separation function of transmitting a polarization component in a certain uniaxial direction and reflecting a polarization component in a direction perpendicular to the polarization component. One example of the application is that the effect of improving luminance is exhibited particularly when incorporated in a liquid crystal display device. This mechanism will be described.

  In FIG. 13, a diffusion sheet 700 is disposed on the upper surface side of the light guide plate 600, a prism sheet 800 is disposed thereon, and a reflection sheet 500 is disposed on the lower surface side of the light guide plate 600. Further, a fluorescent tube 400 is disposed on the side surface of the light guide plate 600. Light emitted from the fluorescent tube 400 enters the light guide plate 600 from the side surface of the light guide plate 600, and exits upward from the upper surface of the light guide plate 600 through the diffusion sheet 700 and the prism sheet 800. The light guide plate 600 is not limited to the above-described configuration example, and the light guide plate 600 may be one having various processing such as dots and prisms on the front and back surfaces, or a plurality of fluorescent tubes 400 may be installed. For the light diffusion sheet 700 and the prism sheet 800, various members and configurations are preferably used, for example, when only one of them is used or when a plurality of sheets are used. FIG. 25 shows an example in which a sidelight type surface light source is used as a surface light source. However, an arbitrary surface light source may be used as the surface light source, even if it is a direct surface light source.

  Next, the optical functional sheet (1) 100 of the present invention and the liquid crystal cell 900 are assembled in order on the upper side of these surface light sources to provide a preferred configuration as a liquid crystal display device.

  In order to achieve a brightness enhancement effect using the optical functional sheet (1) of the present invention, at least in the above liquid crystal device, the direction of the polarization axis transmitted by the light source side polarizing plate constituting the liquid crystal cell 900 and The optical functional sheet (1) 100 of the present invention is installed so as to coincide with the direction of the polarization axis transmitted therethrough.

  In the liquid crystal cell 900, a liquid crystal layer is formed between two polarizing plates. The polarizing plate used in the liquid crystal cell 900 is an absorption-type polarizing plate, and polarized light orthogonal to the transmission axis is absorbed. Therefore, theoretically, the maximum utilization efficiency of light is 50%. When the optical functional sheet (1) of the present invention is installed between the surface light source and the liquid crystal cell, the polarization component that has been absorbed in the past is reflected back to the surface light source side. The polarized component reflected and returned is depolarized by the surface light source unit to become isotropic light, and can be reused again toward the liquid crystal cell. By repeating this cycle, it is possible to increase the light use efficiency as compared with the conventional surface light source that can use only 50% of the total light, and as a result, it is possible to improve the luminance.

  Moreover, when installing the optical functional sheet (1) of this invention in a liquid crystal display device, it is preferable to install a metal layer formation surface toward the liquid crystal cell 900 side. This installation is preferable because it may be possible to suppress a decrease in polarization characteristics even when a resin having birefringence is used as the base 140.

  In the above description, an example in which the optical functional sheet (1) is mounted between the prism sheet 800 and the liquid crystal cell 900 is shown. However, the present invention is not limited to this, and the degree of polarization p is 0.90 or more, more preferably 0.8. If it is as high as 95 or more, more preferably 0.99 or more, it can be used instead of the polarizing plate on the lower side of the liquid crystal cell. In this case, as compared with the case where a conventional iodine-type polarizing plate is used, since it can be reused, a liquid crystal display device with high luminance can be obtained, which is preferable.

  In the optical functional sheet (1) of the present invention, the formed metal layer 250 may be subjected to electrolytic plating, electroless plating, vapor deposition, sputtering, or the like in order to improve the polarization separation performance. Although it does not specifically limit as a metal seed | species, A metal with high reflectance in visible region, for example, silver, chromium, aluminum, titanium etc., is used suitably. In addition, when performing vapor deposition or sputtering, if vapor deposition or sputtering is performed from the normal direction to the film surface direction of the optical functional sheet (1), a metal layer is formed on the entire surface, and as a result, the direction in which transmission is desired. In some cases, the transmittance of the polarized light is also lowered. Therefore, it is preferable to perform vapor deposition or sputtering from the normal direction with respect to the film surface and from an oblique direction perpendicular to the stripe arrangement.

  The optical functional sheet (1) of the present invention is formed on the entire surface including the surface of the metal layer 150 or the entire surface including the metal layer 150 in order to increase the mechanical strength of the formed metal layer 150 or to impart friction resistance to the surface. Further, a protective film made of a transparent resin, a metal oxide film, or the like may be formed. Further, a transparent resin may be filled in the concave portion between the metal layer 150 and the metal layer 150. The transparent resin that can be used is not particularly limited as long as it is transparent to light in the wavelength region to be used, and a thermoplastic resin, a thermosetting resin, a photocurable resin, and the like can be suitably used. Moreover, the metal oxide which can be used should just be transparent with respect to the light of the wavelength range to be used, and is not specifically limited. In addition, another film such as a protective film is preferably laminated on the surface of the optical functional sheet (1) of the present invention.

  Moreover, arbitrary layers, such as an antistatic layer, an antireflection layer, a hard-coat layer, can be formed in the pattern non-formation surface side of the optical functional sheet (1) of this invention. Moreover, it can also be set as the function integrated high performance sheet | seat which has many functions by bonding with the base material etc. which have another function.

(2) Electromagnetic wave shielding film The optical functional sheet (2) obtained by the pattern forming method of the present invention has a function of reflecting or absorbing electromagnetic waves.

  The optical functional sheet (2) of the present invention can be selected in any wavelength region without any special restrictions on the applicable wavelength region by appropriately selecting the shape (pitch, aperture ratio, width, aspect ratio, etc.). An optical functional sheet having electromagnetic wave shielding characteristics can be obtained.

  As a specific shape of the optical functional sheet (2) of the present invention, a metal layer 250 is formed in a pattern on the base 240 as shown in FIG. Since the metal layer is formed, the metal layer 250 functions as an electromagnetic wave shield, and the metal layer 250 is arranged in a pattern on the base material 240. Therefore, the concave portion sandwiched between the metal layer 250 and the metal layer 250 transmits visible light. It is possible. FIG. 14 shows an example in which the surface layer 11 is torn by the intrusion of the mold convex portion, and the metal layer 250 is formed in a pattern on the base portion 240. However, the present invention is not limited to this. Instead, the structures illustrated in FIGS. 15A to 15F are also preferably used. 15 (a) to 15 (c) show a state in which the surface layer 11 is broken at the intrusion portion of the mold protrusion, and FIGS. 15 (d) to 15 (f) show that the surface layer 11 is partially or entirely connected. However, FIG. 15A and FIG. 15D show the case where the entire convex portion is formed of a material constituting the surface layer, and FIG. , (E) shows the case where the surface layer of the convex portion is covered with the surface layer 11, and FIGS. 15 (c) and 15 (f) respectively show the intermediate state.

  15 (a) to 15 (f), the material of the surface layer 11, the thickness L, the cross-sectional area S1, the dynamic storage elastic modulus E1 ′, the material of the base material layer 12, the dynamic storage elasticity. It can be formed by appropriately changing the rate E2 ′, the height H of the mold convex portion 21, the cross-sectional area S2 of the mold concave portion, and the like.

  In the optical functional sheet (2) of the present invention, the preferred shape of the metal layer 250 is a rectangle (see FIG. 14 (a)), a trapezoid (see FIG. 14 (b)), or a triangle (see FIG. 14 (c)). These are modified (see FIGS. 14 (d) to (g)) and their combined shapes, but are not limited to these, and by selecting an appropriate shape, any electromagnetic wave shielding characteristics Can be obtained. In addition, between adjacent linear patterns, when a flat portion is formed as shown in FIGS. 14A to 14F, or continuous without forming a flat portion as shown in FIG. 14G. Any of the cases where they are connected together may be used. 14 (a) to 14 (f), the material of the surface layer 11, the thickness L, the cross-sectional areas S1, E1 ′, the material of the base material layer 12, and the height of the E2 ′ mold projection 21 are obtained. They can be formed by appropriately changing the height H, the cross-sectional area S2 of the mold recess, and the like.

  FIGS. 16A to 16H are cross-sectional views schematically showing the arrangement of the metal layer 250 in a cross section when the optical functional sheet (1) of the present invention is cut in parallel to the film surface. is there.

  As shown in FIGS. 16A to 16H, the shape of the metal layer 250 may have a shape selected from a linear shape, a substantially triangular shape, a substantially rectangular shape, a substantially hexagonal shape, a circle, an ellipse, and the like. 16A to 16C show a case where the metal layer 250 has a stripe shape, FIG. 16D shows a case where the cross section of the metal layer 250 is a circular shape, and FIG. 16E shows a case where the metal layer 250 has a triangular shape. 16 (f) to (g) illustrate a case where the shape is a quadrangle, and FIG. 16 (h) illustrates a case where the shape is a hexagon. The metal layers 250 may be aligned as shown in the figure, may be arranged randomly, or different shapes may be mixed. In addition, as shown in FIGS. 17A to 17D, the shape of the portion where the metal layer 250 does not exist may have a shape selected from a substantially triangular shape, a substantially rectangular shape, a substantially hexagonal shape, a circle, an ellipse, and the like. Good.

  Further, in the cross section in the plane direction of the optical functional sheet (2), the ratio of the area S5 ′ of the convex part of the molded product to the area S5 ″ of the concave part of the molded product (= area of the concave part / area of the convex part) It is preferably ~ 1/1, more preferably 40/1 to 2/1, and if it is larger than this range, the proportion of the metal layer 250 becomes too small, and the electromagnetic wave shielding characteristics are sufficiently exhibited. Or the mechanical strength of the metal layer 250 may be reduced, and this is not preferable, and if it is not within this range, the light transmittance of the entire sheet may be lowered or the transmitted light may be colored. In the optically functional sheet (2) of the present invention, the ratio of the area S4 ′ of the molded product convex portion to the area S4 ″ of the molded product concave portion is set to the above ratio, while maintaining high transparency. Layer 25 Since due can exhibit a sufficient electromagnetic wave shielding properties preferred.

  In the optical functional sheet (2) of the present invention, the ratio (H2 ′ / w22 ′, aspect ratio) of the height H2 ′ of the convex portion in the sheet thickness direction and the concave width w22 ′ in the film surface direction in the sheet cross section. Any visual field control characteristic can be obtained by changing the ratio. That is, when the aspect ratio (H2 '/ w22') is lowered, the viewing angle is widened, and when it is increased, the viewing angle can be narrowed.

  Here, as shown in FIG. 14A, the recess width w22 'is the length between the protrusions in the direction in which the protrusions and the recesses are alternately and repeatedly arranged in the sheet cross section. In the case of a stripe pattern as shown in FIGS. 16A to 16C, or when the metal layer 250 is circular or polygonal as shown in FIGS. 16D to 16H, the metal layer 250 is used. The shortest distance between them is defined as a recess width w22 ′. Further, as shown in FIG. 17 (a), when the concave portion is circular, the diameter is elliptical, and when the concave portion is elliptical, the short diameter is polygonal such as a triangle or a quadrangle as shown in FIGS. In this case, the diameter of the inscribed circle corresponds to the width w22 ′ of the recess. The width w21 'of the metal layer 250 is defined similarly.

  In the optical functional sheet (2) of the present invention, the width w22 'of the recess is preferably 5 to 250 µm. By setting it within this range, when used for a liquid crystal display, a repetitive pattern on a sheet is not visually confirmed, and interference with a pixel pattern is not preferable. Further, the pitch p2 '(= w21' + w22 ') of the repetitive pattern may be constant, may change regularly, or may be random. Note that the width w22 'of the recess is expressed by an average value when the length unit is different in the film thickness direction as shown in FIG.

  Further, the height H2 ′ of the convex portion of the optical functional sheet (2) of the present invention takes into account the ease of pattern formation (process surface), sufficient viewing angle characteristics, and response to thinning, etc. 1-100 μm is preferable.

  Further, the base portion 240 of the optical functional sheet (2) of the present invention includes a flat portion 241 and a convex base portion 242. The height h22 ′ of the base portion 242 is arbitrary, but the thickness l2 ′ of the flat portion 241 is preferably 20 μm to 1 mm, more preferably 30 μm to 500 μm from the viewpoint of mechanical strength and reduction in thickness. More preferably, it is 50-300 micrometers. However, when the support layer is provided under the base portion 240, the thickness l2 'of the flat portion 241 is not particularly limited and may be 20 μm or less.

  Since the optical functional sheet (2) of the present invention has a structure in which the metal layer 250 is arranged in a pattern on the base material 240, the concave portion sandwiched between the metal layer 250 and the metal layer 250 can transmit visible light. Become. Therefore, it can be used not only for measuring devices that generate electromagnetic waves, electronic devices, personal computers, mobile phones, etc., but also as a wall material for electromagnetic shielding rooms. It can also be installed on the front of various displays such as a viewing window, an electromagnetic shielding room window, a CRT, a PDP, and a liquid crystal display.

  In addition, in the optical functional sheet (2) of the present invention, the formed metal layer 250 may be subjected to various metal treatments such as electrolytic plating, electroless plating, vapor deposition, and sputtering in order to improve electromagnetic wave shielding properties. Although it does not specifically limit as a metal seed | species, A metal with high electromagnetic wave shielding property, for example, silver, copper, nickel, gold | metal | money etc. are used suitably. When vapor deposition or sputtering is performed, if a vapor deposition is performed from the normal direction to the film surface direction of the optical functional sheet (2), a metal layer is formed on the entire surface. May drop significantly. Therefore, it is preferable to perform vapor deposition or sputtering from a normal direction to the film surface and from an oblique direction perpendicular to the arrangement direction of the metal layers.

  Moreover, in order for the optical functional sheet (2) of this invention to improve the contrast of a pattern, the surface of the metal layer 250 is also suitably blackened. As a blackening treatment method, for example, the metal layer 250 is oxidized by immersing the optical functional sheet (2) of the present invention in a mixed aqueous solution of sodium chlorite, sodium hydroxide, and trisodium phosphate. Examples thereof include a method of depositing blackened nickel on the surface of the metal layer 250 by electroplating, but are not limited to this, and a known blackening treatment can be performed.

  Further, in order to increase the mechanical strength of the formed metal layer 250 or to impart friction resistance to the surface, a transparent resin or a metal oxide film is formed on the surface of the metal layer 250 or the entire surface on which the metal layer 250 is formed. A protective film may be formed, or a recess between the metal layer 250 and the metal layer 250 may be filled with a transparent resin. The transparent resin that can be used is not particularly limited as long as it is transparent to light in the visible wavelength region, and a thermoplastic resin, a thermosetting resin, a photocurable resin, and the like can be suitably used. Further, the metal oxide that can be used is not particularly limited as long as it is transparent to light in the visible wavelength region. In addition, another film such as a protective film is preferably laminated on the surface of the optical functional sheet (2) of the present invention.

  Moreover, arbitrary layers, such as an antistatic layer, an antireflection layer, a hard-coat layer, can be formed in the pattern non-formation surface side of the optical functional sheet (2) of this invention. Moreover, it can also be set as the function integrated high performance sheet | seat which has many functions by bonding with the base material etc. which have another function.

  When the pattern forming method of the present invention is used, by using metal fine particles or metal-coated fine particles as the fine particles 14, an optical functional sheet such as (1) a reflective polarizing plate and (2) an electromagnetic wave shielding sheet can be produced. Until now, these optical functional sheets had to go through many processes such as photolithography and etching. The pattern forming method of the present invention is excellent in that the production time can be greatly reduced and the cost can be significantly reduced as compared with the conventional method because various optical functional sheets can be formed only by mold transfer.

  In addition to the above examples, the pattern forming method of the present invention can be applied to conductive sheets, electric circuits, etc. In addition, by appropriately selecting the fine particles 14, it can be applied to various industrial fields. A sheet can be formed.

[Characteristic evaluation method]
A. Sectional structure:
Cross sections of the laminate, mold, and molded product were cut out, and after platinum-palladium was deposited, cross-sectional observation was performed using a field emission scanning electron microscope JSM-6700F (manufactured by JEOL Ltd.) and a photograph was taken. From the obtained photographs, the film thickness L of the surface layer 11 of the laminate, the height H of the mold protrusions, and the W between adjacent mold protrusions were determined. Further, the cross-sectional area S1 (= W × L) of the surface layer 11, the width w2 of the mold recess, the cross-sectional area S2, and the average particle diameter R of the fine particles were obtained.

  The average particle diameter R of the fine particles was obtained by randomly obtaining the diameter of 100 particles from the obtained image, and the average value was used as the average particle diameter R.

Further, penetration was determined as follows. Observe the cross-sectional structure of the molded product,
○ when the surface layer is completely penetrated,
△, when the surface layer remains very slightly but almost penetrates
X when the surface layer does not penetrate,
It was.

The transferability was determined as follows. The ratio A ′ / S2 between the sectional area A ′ of the convex part of the molded product and the sectional area S2 of the mold concave part is
0.92 or more: ○,
0.90 or more and less than 0.92: Δ,
Less than 0.90: x,
It was.

B. Fine particle content:
The surface layer was scraped off from the laminate with a cutter, and the weight W1 of the scraped surface layer was measured. Next, acetone was added to the scraped surface layer, and the mixture was stirred by irradiating ultrasonic waves for 5 minutes. After the dispersion was centrifuged, the supernatant was removed by decantation. After this operation was repeated five times, the remaining residue was dried under reduced pressure overnight, then its weight W2 was measured, and the content of fine particles was determined by the following formula.
Fine particle content (%) = (W1-W2) / W1 × 100

C. Reflective polarizing plate property evaluation method:
C-1. Transmittance, wavelength dependence, degree of polarization Using the spectrophotometer U-3410 (manufactured by Hitachi, Ltd.), the total optical transmittance is obtained in the wavelength range of 400 to 800 nm using the obtained optical functional sheet (1). The average value in the wavelength region was defined as the transmittance. Further, the transmittance at each wavelength of 450 nm, 550 nm, and 650 nm was compared, and the difference between the maximum value and the minimum value of the transmittance at three points was obtained and defined as wavelength dependency.

As for the degree of polarization, the glass polarizing filter (manufactured by Edmund Optics Japan Co., Ltd.) and the side on which the sample metal layer 150 is formed are stacked so that the glass polarizing filter is on the light source side (light incident side). In the spectrophotometer, the maximum transmittance Tmax and the minimum transmittance Tmin at 550 nm were measured, and the degree of polarization was obtained by applying to the following equation.
Polarization degree P = ((Tmax−Tmin) / (Tmax + Tmin)) ^0.5

  In each measurement of transmittance and degree of polarization, each reflective polarizing plate sample is placed so that the surface side on which the metal layer is formed is the light source side (light incident side), and the incident angle of the light beam is 0. °.

C-2. Brightness 1 inch square acrylic light guide plate, one fluorescent tube on the side of the light guide plate, reflection sheet “Lumirror” E60L (manufactured by Toray Industries, Inc.) on the lower side of the light guide plate, diffusion sheet “Opulse” BS- on the upper side of the light guide plate A sidelight type surface light source was assembled using 04 (Ewa Co., Ltd.) and prism sheet BEFII (Sumitomo 3M Co., Ltd.). Next, the optical functional sheet (1) of the present invention is overlaid on the prism sheet so that the pattern is on the viewer side, and the direction of the transmission axis of the optical functional sheet (1) of the present invention obtained is further determined. An absorption polarizing plate (LN-1825T, manufactured by Polatechno Co., Ltd.) was placed so as to match, and a surface light source was started up at 12V. Front luminance (a) was measured using a color luminance meter BM-7 / FAST (manufactured by Topcon Corporation). Subsequently, only the optical functional sheet (1) was removed, and the luminance (b) was measured in the same manner. From the obtained results, the luminance improvement rate was calculated from the following formula.
Brightness improvement rate (%) = 100 × ((a) − (b)) / (b)

D. Evaluation of electromagnetic shielding sheet characteristics:
D-1. Transmittance The transmittance was measured using a fully automatic direct reading haze computer HGM-2DP manufactured by Suga Test Instruments Co., Ltd.

D-2. Electromagnetic wave shielding property The electromagnetic wave shielding property of the obtained optical functional sheet (2) is measured using the electromagnetic wave shielding effect measuring device TR-17301 (manufactured by Advantest Co., Ltd.), and the electric field shielding property in the wavelength range of 30 MHz to 1 GHz. Was measured.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not necessarily limited to these.

Example 1
As a base material layer, a fluorene copolymerized polyester (OKP4: manufactured by Osaka Gas Chemical Co., Ltd.), which was vacuum-dried at 110 ° C. for 4 hours, was melted at 280 ° C. in an extruder, and then on a cast drum from a molten die by a predetermined method. To obtain a base material layer having a thickness of 500 μm. After applying a composition comprising 30 parts by weight of silver nanopaste (NPS-J: manufactured by Daiichi Jitsugyo Co., Ltd., average particle size of 5 nm) and 70 parts by weight of hexadecane to this base material layer with a spin coater at 4500 rpm for 30 seconds, A surface layer having a thickness of 60 nm was formed by drying at 160 ° C. for 15 seconds.

  Scan the cross section of the obtained laminate and mold (stripe pattern (pitch 200 nm, width w1 = 100 nm, height H = 150 nm, aspect ratio H / w1 = 1.5 (see FIG. 18A)) From the image obtained by observation with an electron microscope, the film thickness L of the surface layer 11 of the laminate, the cross-sectional area S1, the height H of the mold convex part, the width w2 of the mold concave part, the cross-sectional area S2, the average of the fine particles The particle diameter R was determined, and the results are shown in Table 1. The content of fine particles in the surface layer was determined to be 90.4% by weight.

  Next, both the obtained laminate and the mold were heated to 165 ° C., the sheet surface and the uneven surface of the mold were brought into contact, pressed at 20 MPa, and held for 10 minutes. Then, after cooling to 130 ° C., the press pressure was released, and the mold was cooled to 50 ° C. and released from the mold to obtain a resin molded product.

  When the cross section of the obtained molded product was observed with a scanning electron microscope, the shape of the mold was transferred and the surface layer penetrated, and the stripe pattern (molded with a pitch of 200 nm, a width of 100 nm, and a depth of 150 nm) Product convex part: width w11 ′ = 100 nm, height H1 ′ = 150 nm (surface layer height h11 ′ = 120 nm, base part height h12 ′ = 30 nm), minor axis aspect ratio H1 ′ / w11 ′ = 1.5 ( (See FIG. 18B)).

  The transmittance of the obtained sheet was 13.9%, the wavelength dependency was 26.2%, the degree of polarization was 0.74, and a sheet having polarization characteristics could be obtained. Moreover, when the brightness improvement rate of the obtained sheet | seat was measured, it was 13%, and it turned out that the brightness improvement effect expresses.

Example 2
The film thickness of the surface layer is 40 nm, the mold is a stripe pattern (pitch 150 nm, width w1 = 75 nm, height H = 120 nm, aspect ratio H / w1 = 1.6 (see FIG. 19A), A resin molded product was obtained in the same manner as in Example 1 except that the height H and the mold recess cross-sectional area S2 were as shown in Table 1.

  When the cross section of the obtained molded product was observed with a scanning electron microscope, the shape of the mold was transferred and the surface layer penetrated, and the stripe pattern (molded with a pitch of 150 nm, a width of 75 nm, and a depth of 120 nm) Product convexity: width w11 ′ = 75 nm, height H1 ′ = 120 nm (surface layer height h11 ′ = 80 nm, base portion height h12 ′ = 40 nm), minor axis aspect ratio H1 ′ / w11 ′ = 1.6 ( (See FIG. 19B)).

  The transmittance of the obtained sheet was 14.5%, the wavelength dependency was 20.7%, the degree of polarization was 0.78, and a sheet having polarization characteristics could be obtained. Moreover, when the brightness improvement rate of the obtained sheet | seat was measured, it was 15%, and it turned out that the brightness improvement effect expresses.

Example 3
As a base material layer, a fluorene copolymerized polyester (OKP4: manufactured by Osaka Gas Chemical Co., Ltd.), which was vacuum-dried at 110 ° C. for 4 hours, was melted at 280 ° C. in an extruder, and then on a cast drum from a molten die by a predetermined method. To obtain a base material layer having a thickness of 500 μm. A silver nano paste (Finesphere SVE102: manufactured by Nippon Paint Co., Ltd., average particle size R30 nm) was applied to the base material layer with an applicator, and then dried at 160 ° C. for 2 minutes to form a surface layer having a thickness of 2 μm.

  Scan the cross section of the obtained laminate and mold (stripe pattern (pitch 200 μm, width w1 = 180 μm, height H = 40 μm, aspect ratio H / w1 = 0.22 (see FIG. 20A)) From the image obtained by observation with an electron microscope, the film thickness L of the surface layer 11 of the laminate, the cross-sectional area S1, the height H of the mold convex part, the width w2 of the mold concave part, the cross-sectional area S2, the average of the fine particles The particle size R was determined, and the results are shown in Table 1. The fine particle content of the surface layer was determined to be 92.1% by weight.

  Next, the obtained laminate and the mold were both heated to 165 ° C., the sheet surface and the uneven surface of the mold were brought into contact, pressed at 20 MPa, and held for 10 minutes. Then, after cooling to 130 ° C., the press pressure was released, and the mold was cooled to 50 ° C. and released from the mold to obtain a resin molded product.

  When the cross section of the obtained molded product was observed with a scanning electron microscope, the shape of the mold was transferred and the surface layer penetrated, and the stripe pattern (molded with a pitch of 200 μm, a width of 20 μm, and a depth of 40 μm) Product convexity: width w21 ′ = 20 μm, height H2 ′ = 40 μm (surface layer height h21 ′ = 20 μm, base portion height h22 ′ = 20 μm), short axis aspect ratio H2 ′ / w21 ′ = 2 (FIG. 20) It was confirmed that (b) was formed).

  Moreover, when the characteristic of the obtained sheet | seat was evaluated, the transmittance | permeability was 50.5% and the electromagnetic wave shielding property was 33 dB.

Example 4
Implemented except that the mold was a square lattice pattern (pitch 200 μm, width 180 μm, depth 40 μm (see FIG. 21A, mold convex height H, mold concave sectional area S2 is shown in Table 1) A resin molded product was obtained in the same manner as in Example 1.

  When the cross section of the obtained molded product was observed with a scanning electron microscope, the shape of the mold was transferred and the surface layer penetrated, the pitch was 200 μm, the width w1 = 20 μm, the height H = 40 μm, Square lattice pattern with aspect ratio H2 ′ / w21 ′ = 2 (molded product convex part: width w21 ′ = 20 μm, height H2 ′ = 40 μm (surface layer height h21 ′ = 18 μm, foundation part height h22 ′ = 22 μm) It was confirmed that an aspect ratio of H2 ′ / w21 ′ = 2 (see FIG. 21B) was formed.

  Moreover, when the characteristic of the obtained sheet | seat was evaluated, the transmittance | permeability was 45.1% and the electromagnetic wave shielding property was 36 dB.

Comparative Example 1
A molded product was obtained in the same manner as in Example 1 except that the thickness of the surface layer was 200 nm.
When the cross section of the obtained molded product was observed with a scanning electron microscope, the shape of the mold (see FIG. 22A) was sufficiently transferred, and the stripe pattern (with a pitch of 200 μm, a width of 100 μm, and a depth of 150 μm) Molded product convex part: width w11 ′ = 20 μm, height H1 ′ = 160 μm, aspect ratio H1 ′ / w11 ′ = 1.5 (see FIG. 22B)), but the surface layer penetrated It wasn't.

  The transmittance of the obtained sheet was 2.0%, the wavelength dependency was 32.9%, the degree of polarization was 0.82, and a sheet having polarization characteristics could be obtained. When the improvement rate was measured, the brightness improvement effect was not expressed.

Comparative Example 2
A molded product was obtained in the same manner as in Example 1 except that the film thickness of the surface layer was 100 nm.
When the cross section of the obtained molded product was observed with a scanning electron microscope, the shape of the mold (see FIG. 22A) was sufficiently transferred, and the stripe pattern (with a pitch of 200 μm, a width of 100 μm, and a depth of 150 μm) Molded product convex part: width w11 ′ = 20 μm, height H1 ′ = 160 μm, aspect ratio H1 ′ / w11 ′ = 1.5 (see FIG. 22B)), but the surface layer penetrated It wasn't.

  The transmittance of the obtained sheet was 2.0%, the wavelength dependency was 32.9%, the degree of polarization was 0.82, and a sheet having polarization characteristics could be obtained. When the improvement rate was measured, the brightness improvement effect was not expressed.

Comparative Example 3
The film thickness of the surface layer is 6 μm, the mold is a stripe pattern (pitch 200 μm, width w1 = 180 μm, height H = 5 μm, aspect ratio H / w1 = 0.03 (see FIG. 23A, A resin molded product was obtained in the same manner as in Example 1 except that the height H and the mold recess cross-sectional area S2 were as shown in Table 1.

  When the cross section of the obtained molded product was observed with a scanning electron microscope, the shape of the mold (see FIG. 23A) was sufficiently transferred, and a stripe pattern (with a pitch of 200 μm, a width of 20 μm, and a depth of 5 μm) Molded product convex part: width w21 ′ = 20 μm, height H2 ′ = 5 μm, aspect ratio H2 ′ / w21 ′ = 0.25 (see FIG. 23B)), but the surface layer penetrated It wasn't.

  When the characteristics of the obtained sheet were evaluated, the electromagnetic wave shielding property was 42 dB, but the transmittance was only 0.3%.

Comparative Example 4
A resin molded product was obtained in the same manner as in Example 1 except that the thickness of the surface layer was 6 μm.
When the cross section of the obtained molded product was observed with a scanning electron microscope, the shape of the mold (see FIG. 24A) was sufficiently transferred, and the stripe pattern (with a pitch of 200 μm, a width of 20 μm, and a depth of 40 μm) Molded product convex portion: width w21 ′ = 20 μm, height H2 ′ = 40 μm, aspect ratio H2 ′ / w21 ′ = 2 (see FIG. 24B)), but the surface layer did not penetrate It was.

  When the characteristics of the obtained sheet were evaluated, the electromagnetic wave shielding property was 39 dB, but the transmittance was only 1.8%.

  The molded product obtained by the pattern forming method of the present invention and the pattern forming method using the pattern forming sheet of the present invention can be suitably applied to a display member. It can be applied to various fields such as optical elements, semiconductor integrated materials, biochips and design members.

1A to 1G schematically illustrate the steps of the pattern forming method of the present invention. 2 (a) to 2 (f) are all cross-sectional views showing a molded product obtained by the pattern forming method of the present invention, and schematically show the shape of the pattern 5 in the convex portion of the molded product in the cross-section. This is just an example. FIG. 3A is a cross-sectional view showing the laminate 1 in the pattern forming method of the present invention, which schematically illustrates the film thickness L in the cross-section, and FIG. It is a cross-sectional view which shows the metal mold | die 2 in a pattern formation method, and illustrates the height H of a metal mold | die convex part typically. FIGS. 4A to 4F are all cross-sectional views showing a mold used in the pattern forming method of the present invention, and schematically illustrate the shape of the mold convex portion 21 in the cross-section. . 5A to 5H are cross-sectional views in a cross section parallel to the surface of the mold used in the pattern forming method of the present invention, and schematically illustrate the shape of the mold convex portion 21. FIG. is there. FIGS. 6A to 6D are cross-sectional views in a cross section parallel to the surface of the mold used in the pattern forming method of the present invention, and schematically illustrate the shape of the mold convex portion 21. is there. FIGS. 7A to 7F are cross-sectional views each showing a molded product obtained by the pattern forming method of the present invention, and schematically illustrate the shape of the convex portion of the molded product in the cross-section. is there. 8A to 8H are cross-sectional views in a cross section parallel to the surface of the molded product obtained by the pattern forming method of the present invention, and schematically illustrate the shape of the convex portion of the molded product. It is. 9A to 9D are cross-sectional views in a cross section parallel to the surface of the molded product obtained by the pattern forming method of the present invention, and schematically illustrate the shape of the convex portion of the molded product. It is. 10 (a) to 10 (g) are cross-sectional views showing the optical functional sheet (1) obtained by the pattern forming method of the present invention, and the metal of the optical functional sheet (1) in the cross section. The shape of the layer 150 is illustrated typically. FIGS. 11A to 11F are cross-sectional views showing the optical functional sheet (1) obtained by the pattern forming method of the present invention, and the metal layer 150 in the convex portion of the molded product in the cross-section. These shapes are schematically exemplified. FIG. 12 is a perspective view schematically illustrating the arrangement shape of the metal layers 150 of the optical functional sheet (1) obtained by the pattern forming method of the present invention. FIG. 13 is a diagram schematically showing a configuration when the optical functional sheet (1) of the present invention is incorporated in a liquid crystal display device. FIGS. 14A to 14G are all cross-sectional views showing the optical functional sheet (2) obtained by the pattern forming method of the present invention, and the metal of the optical functional sheet (2) in the cross section. The shape of the layer 250 is illustrated typically. FIGS. 15A to 15F are cross-sectional views showing the optical functional sheet (2) obtained by the pattern forming method of the present invention, and the metal layer 250 in the convex portion of the molded product in the cross-section. These shapes are schematically exemplified. FIGS. 16A to 16H are cross-sectional views in a cross section parallel to the surface of the optical functional sheet (2) obtained by the pattern forming method of the present invention, and the optical functional sheet (2). The shape of the metal layer 250 is illustrated typically. 17A to 17D are cross-sectional views in a cross section parallel to the surface of the optical functional sheet (2) obtained by the pattern forming method of the present invention. The shape of the metal layer 250 is illustrated typically. FIG. 18A is a perspective view schematically showing a part of the mold used in the example, and FIG. 18B is a perspective view schematically showing a part of the molded product shaped in the example. FIG. FIG. 18A is a perspective view schematically showing a part of the mold used in the example, and FIG. 18B is a perspective view schematically showing a part of the molded product shaped in the example. FIG. FIG. 20A is a perspective view schematically showing a part of the mold used in the example, and FIG. 20B is a perspective view schematically showing a part of the molded product shaped in the example. FIG. FIG. 21A is a perspective view schematically showing a part of the mold used in the example, and FIG. 21B is a perspective view schematically showing a part of the molded product shaped in the example. FIG. FIG. 22A is a perspective view schematically showing a part of the mold used in the comparative example, and FIG. 22B is a perspective view schematically showing a part of the molded product shaped in the example. FIG. FIG. 23A is a perspective view schematically showing a part of the mold used in the comparative example, and FIG. 23B is a perspective view schematically showing a part of the molded product shaped in the comparative example. FIG. FIG. 24A is a perspective view schematically showing a part of the mold used in the comparative example, and FIG. 24B is a perspective view schematically showing a part of the molded product shaped in the comparative example. FIG.

Explanation of symbols

1: Laminated body 2: Mold 3: Molded product 4: Base part 5: Pattern 11: Surface layer 12: Base material layer 13: Surface layer matrix 14: Fine particles 21: Mold convex part 22: Mold concave part 41: Molded article Base flat part 42: Molded product base base part 100: Optical functional sheet (1)
140: base portion 141 of the optical functional sheet (1) 1: base flat portion 142 of the optical functional sheet (1): base base portion 150 of the optical functional sheet (1): metal layer 200 of the optical functional sheet (1) : Optical functional sheet (2)
240: Base portion 241 of optical functional sheet (2) 1: Base flat portion 242 of optical functional sheet (2) 242: Base base portion 250 of optical functional sheet (2) 250: Metal layer 400 of optical functional sheet (2) : Fluorescent tube 500: Reflective sheet 600: Light guide plate 700: Diffusion sheet 800: Prism sheet 900: Liquid crystal cell l 1: Parallel line to the film surface direction of the laminate l 2: Perpendicular to the film surface direction of the laminate l 3: To the mold surface Parallel line l4: perpendicular to mold surface L: film thickness of surface layer H: height of mold convex part w1: width of mold convex part w2: width of mold concave part S1: sectional area of surface layer S2: gold Cross-sectional area of mold recess H ': Height of molded product convex part h1': Height of molded product convex pattern part h2 ': Height of molded product convex base part l': Thickness of flat part of molded product w1 ′: width of the convex part of the molded product w2 ′: width of the concave part of the molded product H1 ′: optical Functional sheet (1) Height of convex part h11 ': Optical functional sheet (1) Height of convex part pattern part h12': Optical functional sheet (1) Height of base part of convex part l1 ': Optical function Sheet (1) thickness of flat part w11 ': optical functional sheet (1) width of convex part w12': optical functional sheet (1) width of concave part H2 ': optical functional sheet (2) of convex part Height h21 ': Optical functional sheet (2) Height of convex pattern part h22': Optical functional sheet (2) Height of convex base part l2 ': Optical functional sheet (2) Thickness of flat part W21 ': Optical functional sheet (2) Width of convex part w22': Optical functional sheet (2) Width of concave part

Claims (11)

A pattern forming method of patterning a surface layer by transferring a die to a base material layer and a laminate in which the surface layer is formed on one side or both sides of the base material layer, the following (A), (B) The pattern formation method characterized by satisfy | filling the requirements of.
(A) The surface layer contains at least metal fine particles or metal-coated fine particles whose surface is coated with a metal.
(B) The mold has a surface shape in which the mold convex part height H is larger than the surface layer film thickness L and the mold concave sectional area S2 is larger than the surface layer sectional area S1. The surface layer is penetrated by the convex part of the mold pressed against.   2. The pattern forming method according to claim 1, wherein at the time of transferring the mold, at least the mold and / or the laminate is heated to transfer the mold surface shape to the laminate.   The ratio R / w2 between the average particle diameter R of the metal fine particles or metal-coated fine particles in the surface layer and the width w2 of the mold recess is 0.5 or less, according to any one of claims 1 and 2. The pattern formation method as described.   The pattern forming method according to any one of claims 1 to 3, wherein the average particle diameter R of the metal fine particles or metal-coated fine particles in the surface layer is 0.001 to 50 µm.   The pattern forming method according to claim 1, wherein the content of the metal fine particles or metal-coated fine particles in the surface layer is 80% by weight or more.   6. The pattern forming method according to claim 1, wherein the average particle diameter R of the metal fine particles or metal-coated fine particles in the surface layer is 100 nm or less.   When performing mold transfer, the method includes a step of heat-treating a pattern obtained by mold transfer after heating the mold and / or the laminate to transfer the mold surface shape to the laminate. The pattern forming method according to claim 1.   An optical functional sheet formed by forming a pattern in which a surface layer containing at least metal fine particles or metal-coated fine particles is arranged on the surface of a substrate by the pattern forming method according to claim 1, wherein the uniaxial An optical functional sheet having a polarization separation function of transmitting a polarization component in a direction and reflecting or absorbing a polarization component in a direction perpendicular to the polarization component.   An optical functional sheet in which a pattern in which a surface layer containing at least metal fine particles or metal-coated fine particles is arranged is formed on a substrate surface by the pattern forming method according to claim 1, and reflects an electromagnetic wave Alternatively, an optical functional sheet having a function of absorbing.   A laminate comprising a substrate layer and a surface layer formed on one side or both sides of the substrate layer, wherein the surface layer is made of metal fine particles having an average particle size R of at least 0.001 to 50 μm, or the surface is made of metal. A pattern-forming sheet comprising 80% by weight or more of coated metal-coated fine particles.   The pattern forming sheet according to claim 10, wherein the average particle diameter R of the metal fine particles or metal-coated fine particles in the surface layer is 100 nm or less.

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