JP2008225020A - Optical resin sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical resin sheet having a small coefficient of linear expansion and superior dimensional stability, suitable for a display device, such as a liquid crystal display device, an organic EL display device and an electronic paper. <P>SOLUTION: The optical sheet comprises a transparent substrate comprising a transparent resin and fibrous filler and having an average coefficient of linear expansion ranging from 30°C to 150°C at 40 ppm or lower, and a wire grid type polarizing layer having thin long metal elements laid parallel to one another at an equal interval on at least one surface of the substrate. The transparent resin is preferably formed by making a resin composition containing a cationic polymerizable component cure. The cationic polymerizable component contains a compound having one or more kinds of epoxy groups, a compound having an oxetanyl group, or a compound having a vinylether group. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical resin sheet having a small coefficient of linear expansion and excellent dimensional stability, which is suitable for a display device such as a liquid crystal display device, an organic EL display device, and electronic paper.

  At present, liquid crystal display devices are widely used as display media. The liquid crystal panel has a structure in which a liquid crystal cell is formed by sandwiching liquid crystal between two transparent substrates, and polarizing plates are arranged on both surfaces of the cell. A liquid crystal display device is configured by combining this panel with a driving LSI and a backlight.

  By the way, such a liquid crystal display device does not necessarily have high use efficiency of light emitted from the backlight. This is because 50% of the light emitted from the backlight is theoretically absorbed by the back polarizer. Therefore, a configuration in which a reflective polarizing plate is arranged between the back-side polarizing plate and the backlight in order to increase the utilization efficiency of the backlight in the liquid crystal display device is known and applied to a liquid crystal television or the like.

  The reflective polarizing plate reflects some kinds of polarized light and transmits polarized light having a 90 ° vibration plane different from that. Axes are aligned so that light transmitted through the reflective polarizing plate passes through the back polarizing plate as linearly polarized light. The polarized light reflected by the reflective polarizing plate returns to the backlight side, is reflected by the reflecting plate, and is reused, thereby increasing the utilization efficiency of the light emitted from the backlight.

  As such a reflective polarizing plate, for example, a reflective polarizing plate in which a cholesteric liquid crystal layer and a quarter-wave plate described in Patent Literature 1 and Patent Literature 2 are combined, and described in Patent Literature 3 and Patent Literature 4. A reflective polarizing plate composed of a multi-layered film of a birefringent layer and an isotropic layer is known.

  A reflective polarizing plate combining a cholesteric liquid crystal layer and a quarter wave plate transmits right (or left) circularly polarized light having a wavelength corresponding to the helical pitch of the cholesteric liquid crystal and converts it into linearly polarized light with the quarter wave plate. Reflects left (or right) circularly polarized light. However, with this reflective polarizing plate, it is difficult to convert right (or left) circularly polarized light transmitted through the cholesteric liquid crystal layer to linearly polarized light with a single quarter-wave plate over the entire visible light range (Patent Literature). 2, paragraph 0007). In order to solve this difficulty, it is necessary to laminate and form a plurality of quarter-wave plates. When a plurality of quarter-wave plates are stacked, the manufacturing process becomes complicated, and there is a problem that peeling may occur between the quarter-wave plates.

  In a reflective polarizing plate composed of a multi-layered film of a birefringent layer and an isotropic layer, it is necessary to form several hundreds of alternately laminated structures, and a large-scale manufacturing facility is required. In addition, since different materials are laminated, there is a problem that peeling is likely to occur between layers.

In addition, when an optical member such as a polarizing plate, a reflective polarizing plate, and a wave plate each having a thickness of 0.1 to 0.2 mm is further laminated on a transparent substrate that holds the liquid crystal, As the thickness of the liquid crystal panel increases, the characteristics of the liquid crystal panel, which is a thin display element, are impaired. Therefore, thinning of each member, reduction in the number of members, and integration of functions of each member are required, and heat resistance and dimensional stability are also required for the member including the substrate of the display element.
JP-A-6-281814 JP-A-8-271731 Japanese National Patent Publication No. 9-506837 Japanese National Patent Publication No. 10-511322

  An object of the present invention is to provide an optical resin sheet having a small linear expansion coefficient and excellent dimensional stability, which is suitable for a display device such as a liquid crystal display device, an organic EL display device, and electronic paper.

（４）前記透明樹脂と前記繊維状フィラーとの屈折率差が０．０１以下である（１）〜（３）何れか記載の光学樹脂シート。
（５）前記繊維状フィラーがガラス繊維布である（１）〜（４）何れか記載の偏光シート。
（６）前記ガラス繊維布が平織りの織布であり、織布の縦糸または横糸と同一方向に、前記ワイヤグリッド型偏光層の細長い金属要素が互いに平行に、同じ間隔をおいて配置されている（１）〜（５）何れか記載の光学樹脂シート。
（７）（１）〜（６）何れか記載の光学樹脂シートの偏光層が形成されていない面に吸収型偏光板を両者の吸収軸を一致させて積層した積層光学シート。
（８）（７）記載の積層光学シートの吸収型偏光板を積層した面に更に位相差層を積層した積層光学シート。
（９）（１）〜（６）何れか記載の光学樹脂シートにおいて、前記偏光層が形成されている面に、更に位相差層を有する積層光学シート。
（１０）（１）〜（６）何れか記載の光学樹脂シートにおいて、前記偏光層が形成されていない面に、更に位相差層を有する積層光学シート。
（１１）（７）〜（１０）何れか記載の積層光学シートを用いた液晶表示用プラスチック基板。
（１２）（８）〜（１０）何れか記載の積層光学シートを用いた有機ＥＬ用プラスチック基板。
（１３）（８）〜（１０）何れか記載の積層光学シートを用いた電子ペーパー用プラスチック基板。 The present invention is as follows.
(1) Elongated metal elements are arranged in parallel with each other at the same interval on at least one side of a transparent substrate made of a transparent resin and a fibrous filler and having an average linear expansion coefficient at 30 to 150 ° C. of 40 ppm or less. An optical resin sheet on which a wire grid type polarizing layer is formed.
(2) The transparent resin is obtained by curing a resin composition containing a cationically polymerizable component, and the cationically polymerizable component is a compound having one or more epoxy groups, an oxetanyl group. The optical resin sheet according to (1), comprising a compound having a compound having a vinyl ether group.
(3) The optical resin sheet according to (1) or (2), wherein the transparent resin is obtained by curing a resin composition containing an alicyclic epoxy resin represented by the chemical formula (1) as a main component.

(4) The optical resin sheet according to any one of (1) to (3), wherein a difference in refractive index between the transparent resin and the fibrous filler is 0.01 or less.
(5) The polarizing sheet according to any one of (1) to (4), wherein the fibrous filler is a glass fiber cloth.
(6) The glass fiber cloth is a plain woven cloth, and the elongated metal elements of the wire grid type polarizing layer are arranged in parallel with each other at the same interval in the same direction as the warp or weft of the woven cloth. The optical resin sheet according to any one of (1) to (5).
(7) A laminated optical sheet obtained by laminating an absorption-type polarizing plate on a surface of the optical resin sheet according to any one of (1) to (6) on which a polarizing layer is not formed so that both absorption axes coincide with each other.
(8) A laminated optical sheet in which a retardation layer is further laminated on the surface of the laminated optical sheet according to (7), on which the absorption-type polarizing plate is laminated.
(9) The optical resin sheet according to any one of (1) to (6), further comprising a retardation layer on the surface on which the polarizing layer is formed.
(10) The optical resin sheet according to any one of (1) to (6), further comprising a retardation layer on a surface on which the polarizing layer is not formed.
(11) A plastic substrate for liquid crystal display using the laminated optical sheet according to any one of (7) to (10).
(12) A plastic substrate for organic EL using the laminated optical sheet according to any one of (8) to (10).
(13) A plastic substrate for electronic paper using the laminated optical sheet according to any one of (8) to (10).

  The optical resin sheet of the present invention has a polarizing function that has a small linear expansion coefficient and excellent dimensional stability, and has a thinner display element, improved luminance of a liquid crystal display device, and visual recognition of an organic EL display element and electronic paper. It can be applied as a useful optical resin sheet that contributes to the improvement of properties.

Hereinafter, the present invention will be described in detail.
In the present invention, elongated metal elements are arranged in parallel with each other at the same interval on at least one side of a transparent substrate comprising a transparent resin and a fibrous filler and having an average linear expansion coefficient at 30 to 150 ° C. of 40 ppm or less. It is the optical resin sheet in which the wire grid type polarizing layer used was formed. In order to show good polarization separation performance in the visible range, it is necessary to regularly arrange metal elements with a dimensional accuracy of about 100 nm or less, so a transparent substrate on which metal elements are arranged requires high dimensional stability. It is necessary that the average linear expansion coefficient at 30 to 150 ° C. is 40 ppm or less.

  The optical resin sheet of the present invention has a polarization function of transmitting a polarized component that vibrates in one direction and reflecting a polarized component that vibrates in a direction 90 ° different from the transmitted polarized component. The wire grid type polarizing layer formed on the surface of the transparent substrate has a structure in which metal elements are arranged in parallel on the transparent substrate with respect to incident light in a non-polarized state. When the pitch, which is the distance between the elongated metal elements, is sufficiently shorter than the wavelength of the incident light, polarized light having a vibration component orthogonal to the metal element is transmitted and polarized light having a vibration component parallel to the metal element. Is reflected.

  As the transparent resin used for the transparent substrate of the optical resin sheet of the present invention, various resins can be used and are not particularly limited, but the resin composition containing a cationically polymerizable component is cured. Examples of the component capable of cationic polymerization include a compound having an epoxy group, a compound having an oxetanyl group, and a vinyl ether group.

  Examples of the compound having an epoxy group include a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, or a hydrogenated product thereof, an epoxy resin having a dicyclopentadiene skeleton, and a triglycidyl isocyanurate skeleton. Examples of epoxy resins, epoxy resins having a cardo skeleton, and alicyclic epoxy resins include 3,4-epoxycyclohexylmethyl 3 ′, 4′-epoxycyclohexylcarboxylate, 1,8,9, diepoxy limonene, dicyclopentadiene diene. 3,4-epoxycyclohexylmethanol and 3,4-epoxycyclohexylcarboxylic acid are attached to both ends of oxide, cyclooctene dioxide, acetal diepoxyside, and ε-caprolactone oligomer, respectively. Tellurium-bonded ones, epoxidized hexahydrobenzyl alcohol, alicyclic polyfunctional epoxy resins, alicyclic epoxy resins having a hydrogenated biphenyl skeleton, alicyclic epoxy resins having a hydrogenated bisphenol A skeleton, etc. It is done.

Examples of the compound having an oxetanyl group include 1,4-bis {[(3-ethyl-3-oxetanyl) methoxy] methyl} benzene (arone oxetane OXT-121 (XDO)), di [2- (3-oxetanyl) butyl. ] Ether (Aron oxetane OXT-221 (DOX)), 1,4-bis [(3-ethyloxetane-3-yl) methoxy] benzene (HQOX), 1,3-bis [(3-ethyloxetane-3- Yl) methoxy] benzene (RSOX), 1,2-bis [(3-ethyloxetane-3-yl) methoxy] benzene (CTOX), 4,4′-bis [(3-ethyloxetane-3-yl) methoxy ] Biphenyl (4,4'-BPOX), 2,2'-bis [(3-ethyl-3-oxetanyl) methoxy] biphenyl (2,2'-BPOX) ), 3,3 ′, 5,5′-tetramethyl [4,4′-bis (3-ethyloxetane-3-yl) methoxy] biphenyl (TM-BPOX), 2,7-bis [(3-ethyl Oxetane-3-yl) methoxy] naphthalene (2,7-NpDOX), 1,6-bis [(3-ethyloxetane-3-yl) methoxy] -2,2,3,3,4,4,5,5 5-octafluorohexane (OFH-DOX), 3 (4), 8 (9) -bis [(1-ethyl-3-oxetanyl) methoxymethyl] -tricyclo [5.2.1.0 ^2.6 ] decane, , 2-bis [2-{(1-ethyl-3-oxetanyl) methoxy} ethylthio] ethane, 4,4′-bis [(1-ethyl-3-oxetanyl) methyl] thiodibenzenethioether, 2,3- Bis [(3-ethyloxetane- -Yl) methoxymethyl] norbornane (NDMOX), 2-ethyl-2-[(3-ethyloxetane-3-yl) methoxymethyl] -1,3-O-bis [(1-ethyl-3-oxetanyl) methyl ] -Propane-1,3-diol (TMPTOX), 2,2-dimethyl-1,3-O-bis [(3-ethyloxetane-3-yl) methyl] -propane-1,3-diol (NPGOX) 2-butyl-2-ethyl-1,3-O-bis [(3-ethyloxetane-3-yl) methyl] -propane-1,3-diol, 1,4-O-bis [(3-ethyl Oxetane-3-yl) methyl] -butane-1,4-diol, 2,4,6-O-tris [(3-ethyloxetane-3-yl) methyl] cyanuric acid, bisphenol A and 3-ethyl-3 - Etherified product of romethyloxetane (abbreviated as OXC) (BisAOX), etherified product of bisphenol F and OXC (BisFOX), etherified product of phenol novolac and OXC (PNOX), etherified product of cresol novolac and OXC (CNOX), oxetanylsil Sesquioxane (OX-SQ), 3-ethyl-3-hydroxymethyloxetane silicon alkoxide (OX-SC) 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane (Aron oxetane OXT-212 ( EHOX)), 3-ethyl-3- (dodecyloxymethyl) oxetane (OXR-12), 3-ethyl-3- (octadecyloxymethyl) oxetane (OXR-18), 3-ethyl-3- (phenoxy) Methyl) oxetane (Aron oxetane OXT-211 (POX)), 3-ethyl-3-hydroxymethyloxetane (OXA), 3- (cyclohexyloxy) methyl-3-ethyloxetane (CHOX) and the like. Here, the parentheses are product names or abbreviations of Toagosei Co., Ltd.

  The compound having a vinyl ether group is not particularly limited, but 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol vinyl ether, triethylene glycol divinyl ether, cyclohexanedimethanol divinyl ether, cyclohexanedimethanol monovinyl ether, Examples thereof include tricyclodecane vinyl ether, cyclohexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, pentaerythritol type tetravinyl ether, and the like.

  Among these, it is particularly preferable that the resin composition is obtained by curing a resin composition containing the alicyclic epoxy resin represented by the chemical formula (1) as a main component. This is because the linear expansion coefficient (αm) of the cured product to which the chemical formula (1) is applied is small, so that the linear expansion coefficient when combined with the fiber cloth can be reduced.

  Moreover, in order to cure these resins and compounds, when cured alone, they can be cured using a cationic catalyst or an anionic catalyst, and can also be cured using various curing agents. For example, in the case of an epoxy resin, it can be cured using an acid anhydride or an aliphatic amine.

  Examples of the cationic curing catalyst include those that release a substance that initiates cationic polymerization upon heating (for example, an onium salt cationic thermal cationic curing catalyst or an aluminum chelate cationic curing catalyst), and cationic polymerization using active energy rays. (For example, an onium salt-based cationic curing catalyst) that releases a substance that initiates the reaction. Among these, a thermal cationic curing catalyst is preferable. Thereby, the hardened | cured material which is more excellent in heat resistance can be obtained.

  Examples of the thermal cationic curing catalyst include aromatic sulfonium salts, aromatic iodonium salts, ammonium salts, aluminum chelates, and boron trifluoride amine complexes. Specific examples of aromatic sulfonium salts include hexafluoroantimonate salts such as SI-60L, SI-80L, SI-100L manufactured by Sanshin Chemical Industries, and SP-66 and SP-77 manufactured by Asahi Denka Kogyo. Examples of the aluminum chelate include ethyl acetoacetate aluminum diisopropylate and aluminum tris (ethyl acetoacetate). Examples of the boron trifluoride amine complex include boron trifluoride monoethylamine complex, boron trifluoride imidazole complex, and trifluoride. Examples thereof include boron bromide piperidine complexes.

  The content of the cationic catalyst is not particularly limited. For example, when the epoxy resin represented by the formula (1) is used, the content is preferably 0.1 to 3 parts by weight with respect to 100 parts by weight of the epoxy resin. 0.5 to 1.5 parts by weight is particularly preferable. If the content is less than the lower limit, the curability may be lowered, and if the content exceeds the upper limit, the resin sheet may be brittle. If necessary, a sensitizer and an acid proliferating agent can be used together to accelerate the curing reaction.

  In order to improve the transparency by combining the refractive index of the fiber cloth and the resin in the optical resin sheet of the present invention, a refractive index adjusting component such as resin, organic fine particles and inorganic fine particles can be added to the transparent resin. . If the refractive index of the main component resin is higher than the refractive index of the fiber cloth used, the refractive index adjusting component can be added with a component lower than the refractive index of the fiber cloth, and conversely, the refractive index of the main component. Is lower than the fiber cloth used, a component higher than the refractive index of the fiber cloth can be added.

  When a resin is added as a refractive index adjusting component, it is preferable to add a cationically polymerizable component that is a compound having a functional group that undergoes a crosslinking reaction with the main component resin. The cationically polymerizable component is preferably a compound having one or more epoxy groups, a compound having an oxetanyl group, or a compound having a vinyl ether group.

  For example, an alicyclic epoxy monomer having a silsesqui skeleton, an oxetane monomer having a silsesqui skeleton, an oligomer having a silicate structure (manufactured by Konishi Chemical: PSQ resin, manufactured by Toa Gosei: oxetanyl silsesquioxane, oxetanyl silicate), β- (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane and the like. In particular, oxetanyl silicate represented by the chemical formula (2) is preferable.

ｎは1〜５の整数

n is an integer from 1 to 5

When inorganic fine particles are added as the refractive index adjusting component, for example, nanoparticles, glass beads and the like can be mentioned, and particles having an average dispersed particle diameter of 100 nm or less are preferable.
Specific examples include silica fine particles having a silicate structure, titanium oxide fine particles, zirconia oxide fine particles, and alumina fine particles. These particles can be appropriately used for adjusting the refractive index.

For example, when the refractive index of the resin as the main component is higher than the refractive index of the fiber cloth, silica fine particles having a lower refractive index than the fiber cloth are preferable. Thereby, high transparency can be obtained without deteriorating the physical properties of the cured product such as heat resistance and linear expansion coefficient.
Of the same silica fine particles, silica fine particles that have been surface-treated are more preferred. This is because active hydrogen (silanol group) that promotes cationic polymerization exists on the surface of the fine particles, and when there is no surface treatment, the curing reaction proceeds and the storage stability is low.

  Although the refractive index of the fiber cloth used for this invention is not specifically limited, 1.4-1.6 are preferable and especially 1.5-1.55 are preferable. This is because the closer the Abbe number of the transparent resin and the Abbe number of the fiber cloth, the higher the refractive index in a wide wavelength region, and the higher the light transmittance in a wide range.

  Examples of the fiber cloth used in the present invention include fiber cloths such as glass fiber and resin fiber. Among them, a woven cloth of glass fiber is preferable because the effect of reducing the linear expansion coefficient is high, and glass cloth is most preferable.

  The types of glass include E glass, C glass, A glass, S glass, T glass, D glass, NE glass, quartz, low dielectric constant glass, and high dielectric constant glass, among which ionic impurities such as alkali metals E glass, S glass, and T glass NE glass, which are easy to obtain with little, are preferable.

  The blending amount of the fiber cloth is preferably 1 to 90% by weight, more preferably 10 to 80% by weight, and further preferably 30 to 70% by weight with respect to the transparent substrate. If the blending amount of the fiber cloth is within this range, molding is easy, and the effect of lowering linear expansion due to compounding is recognized.

  The thickness of the transparent substrate is preferably 50 to 2000 μm, more preferably 50 to 1000 μm, and most preferably 50 to 200 μm.

  It is preferable that the average linear expansion coefficient in 30 to 150 degreeC of a transparent base material is 40 ppm or less, More preferably, it is 30 ppm or less, Most preferably, it is 20 ppm or less.

  There is no limitation on the method for producing the transparent substrate of the present invention, for example, a method in which an uncured resin composition and a fibrous filler are directly mixed, cast into a necessary one, and then cross-linked into a sheet, uncured The resin composition is dissolved in a solvent and the fibrous filler is dispersed and cast, and then crosslinked to form a sheet. An uncured resin composition or a varnish in which the resin composition is dissolved in a solvent is used as a woven filler or Examples include a method of impregnating a non-woven filler and then crosslinking to form a sheet.

  In the optical resin sheet of the present invention, a wire grid type metal element is formed on at least one side of the transparent substrate. In the wire grid type metal element, fine metal wires are arranged in parallel with each other and at the same interval. The material of the metal element is not particularly limited, but it is preferable to use a metal material such as silver or aluminum that exhibits high reflectivity with respect to visible light and has high conductivity.

  The required height t (metal thickness) of the metal element is determined from the polarization separation performance of the wire grid type polarization layer. Specifically, the light transmittance may be 1% or less, and is 30 to 200 nm. It is preferable.

  When the visible light is polarized and separated, the pitch of the metal elements is preferably 400 nm or less.

  The width (w) of the metal element is in the range of 0.3p <w <0.7p because the polarization separation performance of the wire grid polarizer improves when the width is about half of the pitch (p). Is preferred.

  The metal element of the wire grid type polarization layer is very fine in both thickness and width, and the polarization separation performance deteriorates due to slight scratches. Therefore, in order to prevent the damage, the metal element can be formed with a protective layer. The protective layer is also effective for preventing rust on the surface of fine metal wires. When metal that easily oxidizes, such as silver or aluminum, is used for the metal element, it suppresses the decrease in polarization separation performance due to the decrease in conductivity of the metal element. In addition, it is preferable to form a protective layer. The material of the protective layer is not limited as long as the function of the wire grid polarizing layer is not impaired, but the refractive index of the protective layer is preferably small, and is preferably 1.0 to 1.3. The protective layer preferably contains a porous body as a main component, and examples of the porous body include organic or inorganic porous bodies, that is, silica airgel, alumina airgel, polyimide pores, and the like. The porous body preferably has a pore diameter smaller than the wavelength of visible light, and preferably has a pore diameter of 100 nm or less.

  Examples of the method for producing the wire grid type polarizing layer include an interference exposure method using an extreme ultraviolet laser and a production method using electron beam lithography. These are methods for producing a metal element having a desired pitch, wire width, and thickness by a lithography technique. Moreover, after printing the compound which can coat | cover the metal thin film which the transparent base material formed by the nanoprint method, the method of producing a metal element by the method of etching away the metal part which is not coat | covered is also mentioned.

  The optical resin sheet of the present invention can be appropriately laminated with an optical functional sheet such as an absorption polarizing plate or a retardation plate depending on the display element to be applied. Examples of the laminating method include laminating with an adhesive and a method of directly forming a functional layer on an optical resin sheet. For example, when producing a thin liquid crystal panel, an optical resin sheet on which a transparent electrode / liquid crystal alignment film is formed is used, and the optical resin sheet / twist nematic liquid crystal / opposing transparent substrate / absorptive polarizing plate (polarized light) from the backlight side. The axis structure may be a layer structure perpendicular to the polarization axis of the optical resin sheet. When producing a liquid crystal panel with a high viewing angle and a high-definition light utilization efficiency, a laminated optical sheet in which an optical resin sheet / absorptive polarizing plate / retardation plate is laminated is used. The layer structure of liquid crystal / opposing transparent substrate / retardation plate / absorption-type polarizing plate (transparent electrode and alignment film are omitted) is raised. In the case of producing an organic EL panel with reduced external light reflection, a laminated optical sheet in which a slow axis of a quarter wavelength plate is laminated in a 45 ° azimuth direction from the polarization transmission axis of the optical resin sheet is used. A configuration in which an EL element is formed on the four-wavelength plate side is raised.

EXAMPLES Hereinafter, although the content of this invention is demonstrated in detail by an Example, this invention is not limited to the following examples, unless the summary is exceeded. Evaluation was performed by the following method.
(A) Average linear expansion coefficient Using a TMA / SS6000 type thermal stress strain measuring device manufactured by SEIKO ELECTRONICS CO., LTD., The temperature was increased at a rate of 5 ° C. per minute in a nitrogen atmosphere. The load was set to 5 g, the measurement was performed in the tensile mode, and the average coefficient of linear expansion from 30 ° C to 150 ° C was calculated.
(B) Refractive index Only the resin composition used for the transparent base material was cured under the same curing conditions as the transparent base material of the example, and the refractive index at a wavelength of 598 nm was measured with an Abbe refractometer.
(C) Polarization degree, single transmittance The single transmittance was measured using a spectrophotometer U3200 (manufactured by Shimadzu Corporation). The polarization degree was parallel polarized light transmittance (T1) and vertical polarized light transmittance (T2) at a wavelength of 550 nm. Was calculated and the degree of polarization = ((T1−T2) / (T1 + T2)).
(D) Heat resistance The maximum value of tanδ at 1 Hz was defined as the glass transition temperature (Tg) using a DNS210 type dynamic viscoelasticity measuring device manufactured by SEIKO ELECTRONICS.

Example 1
100 weight of hydrogenated biphenyl type alicyclic epoxy resin (Daicel Chemical Industries, E-BP) having a structure of chemical formula (1) on T glass-based glass cloth (thickness 90 μm, refractive index 1.523, manufactured by Nittobo) Part and a resin composition mixed with 1 part by weight of an aromatic sulfonium-based thermal cation catalyst (SI-100L manufactured by Sanshin Chemical) were defoamed. This resin-impregnated glass cloth was sandwiched between release-molded glass substrates, heated at 80 ° C. for 2 hours, and further heated at 250 ° C. for 2 hours to obtain a transparent substrate having a thickness of 100 μm.
Next, after forming an aluminum layer having a thickness of 100 nm on one side of the transparent substrate by resistance heating vapor deposition, a photoresist diluted with anisole on the aluminum surface formed on the transparent substrate (ZEP520A-7 manufactured by Nippon Zeon Co., Ltd.) A 150 nm thick photoresist layer was formed by spin coating.
Next, by an electron beam drawing method using an electron beam drawing apparatus (ELS-3700 manufactured by Elionix Co., Ltd.), a linear pattern having a width of 100 nm is formed at a pitch of 200 nm in a direction parallel to the warp direction of the glass cloth used for the transparent substrate. After the formation, the aluminum in the electron beam exposure part was removed using a dry etching method. The photoresist layer remaining on the aluminum fine wire was developed with dimethylacetamide to obtain an optical resin sheet of a transparent substrate with a wire grid type polarizing layer.
The evaluation results of the obtained optical resin sheet are shown below.
Refractive index after curing of resin composition of transparent substrate: 1.524
Average linear expansion coefficient of transparent substrate: 13 ppm
Heat resistance of transparent substrate:> 250 ° C
Single transmittance of optical resin sheet: 44%
Polarization degree of optical resin sheet: 99%

Claims (13)

A wire composed of a transparent resin and a fibrous filler and having elongated metal elements arranged in parallel with each other at the same interval on at least one side of a transparent base material having an average linear expansion coefficient of 40 ppm or less at 30 to 150 ° C. An optical resin sheet on which a grid-type polarizing layer is formed. The transparent resin is obtained by curing a resin composition containing a cationically polymerizable component, and the cationically polymerizable component is a compound having one or more epoxy groups, a compound having an oxetanyl group, Or the optical resin sheet of Claim 1 containing the compound which has a vinyl ether group. The optical resin sheet according to claim 1 or 2, wherein the transparent resin is obtained by curing a resin composition containing an alicyclic epoxy resin represented by the chemical formula (1) as a main component.

The optical resin sheet according to any one of claims 1 to 3, wherein a difference in refractive index between the transparent resin and the fibrous filler is 0.01 or less. The polarizing sheet according to any one of claims 1 to 4, wherein the fibrous filler is a glass fiber cloth. 2. The glass fiber cloth is a plain woven cloth, and the elongated metal elements of the wire grid type polarizing layer are arranged in parallel with each other at the same interval in the same direction as the warp or weft of the woven cloth. -Optical resin sheet in any one of -5. A laminated optical sheet obtained by laminating an absorption-type polarizing plate on the surface of the optical resin sheet according to any one of claims 1 to 6 so that both absorption axes coincide with each other. The laminated optical sheet which laminated | stacked the phase difference layer further on the surface which laminated | stacked the absorption-type polarizing plate of the laminated optical sheet of Claim 7. The optical resin sheet according to claim 1, further comprising a retardation layer on the surface on which the polarizing layer is formed. The optical resin sheet according to claim 1, further comprising a retardation layer on a surface on which the polarizing layer is not formed. A plastic substrate for liquid crystal display using the laminated optical sheet according to claim 7. A plastic substrate for organic EL using the laminated optical sheet according to claim 8. A plastic substrate for electronic paper using the laminated optical sheet according to claim 8.