JP2008224825A - Optical sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical sheet having an optical element with a low coefficient of linear expansion and superior dimensional stability, suitable for a sharp three-dimensional display device. <P>SOLUTION: The optical sheet comprises a transparent substrate made of a first transparent resin and fibrous filler, having an average coefficient of linear expansion ranging from 30°C to 150°C at 40 ppm or lower, and an optical element essentially comprising a second transparent resin formed on the transparent substrate. The first transparent resin or the second transparent resin is preferably formed by curing a resin composition containing a cationic polymerizable component. 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 sheet having an optical element having a small linear expansion coefficient and excellent in dimensional stability.

  As a stereoscopic image observation method, for example, a method of observing parallax images based on mutually different polarization states using polarized glasses, or a predetermined parallax image from a plurality of parallax images using a lenticular lens is observed by an observer's eyeball. A method of guiding light is proposed.

  For example, in the case of a display capable of observing a stereoscopic image without glasses using a lenticular lens, two parallax images corresponding to two viewpoints for the right eye and the left eye are displayed on a display pixel unit such as a liquid crystal display. A three-dimensional image is formed by combining lenticular lenses with pitches corresponding to parallax pixels, which are alternately displayed in stripes in the horizontal direction of the screen.

The stereoscopic image is affected by the positional accuracy of the lenticular lens and the parallax pixel. In recent years, with the increase in the resolution of display images, the pixel pitch has also decreased, and in conventional PET films, the positional accuracy of the parallax pixels and the lens sheet is shifted depending on the usage environment, and a clear stereoscopic image can be obtained. It's hard to get caught.
Also, Fresnel lens sheets used in projectors, prism lens sheets and microlens sheets used to increase the brightness of liquid crystal display elements may cause deviations from the optical design values of each optical element depending on the usage environment, so optical elements are formed. Improvement of the dimensional stability of a transparent substrate is desired.

  An object of the present invention is to provide an optical sheet on which an optical element having a small linear expansion coefficient and excellent dimensional stability, which is suitable for a clear three-dimensional display device.

The present invention is as follows.
(1) An optical element mainly composed of the second transparent resin was formed on a transparent base material comprising the first transparent resin and a fibrous filler and having an average linear expansion coefficient at 30 to 150 ° C. of 40 ppm or less. Optical sheet.
(2) The optical sheet according to (1), wherein the optical element is a lenticular lens.
(3) The optical sheet according to (1), wherein the optical element is a prism lens.
(4) The optical sheet according to (1), wherein the optical element is a microlens.
(5) The optical sheet according to (1), wherein the optical element is a Fresnel lens.
(6) The first transparent resin or the second transparent resin is obtained by curing a resin composition containing a cationic polymerizable component, and the cationic polymerizable component is one type or two or more types of epoxy. The optical sheet according to any one of (1) to (5), comprising a compound having a group, a compound having an oxetanyl group, or a compound having a vinyl ether group.
(7) The first transparent resin or the second transparent resin is obtained by curing a resin composition containing an alicyclic epoxy resin represented by the chemical formula (1) as a main component (1) to (5 ) Any one of the optical sheets.

(8) The optical sheet according to any one of (1) to (7), wherein a difference in refractive index between the first transparent resin and the fibrous filler is 0.01 or less.
(9) The optical sheet according to any one of (1) to (8), wherein the fibrous filler is a glass fiber cloth.

  The optical sheet of the present invention has a small coefficient of linear expansion and excellent dimensional stability. By using the optical sheet, for example, a lenticular lens sheet applied to a stereoscopic display device suitable for a television, a computer monitor, a game machine, etc. Display bodies and projector screens that require optical elements can be provided.

Hereinafter, the present invention will be described in detail.
As the first transparent resin used for the transparent substrate of the present invention, various resins can be used and are not particularly limited. However, the resin composition containing a cationically polymerizable component is cured. What is obtained is preferable, and examples of the component capable of cationic polymerization include a compound having an epoxy group, a compound having an oxetanyl group, or 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. Examples include ter-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, and the like. 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 above 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, cyclohexane dimethanol divinyl ether, cyclohexane dimethanol 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 fibrous filler can be reduced.

  In order to cure these resins and compounds, in the case of curing 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 transparent substrate 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 fibrous filler and the resin in the transparent substrate of the present invention, a refractive index adjusting component such as resin, organic fine particles, inorganic fine particles may be added to the transparent resin. it can. When the refractive index of the main component resin is higher than the refractive index of the fibrous filler used, the refractive index adjusting component can be added with a component lower than the refractive index of the fibrous filler. When the refractive index is lower than the fibrous filler used, a component higher than the refractive index of the fibrous filler 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 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 fibrous filler, silica fine particles having a refractive index lower than that of the fibrous filler 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 fibrous filler used for this invention is not specifically limited, 1.4-1.6 are preferable and 1.5-1.55 are especially preferable. This is because the closer the Abbe number of the transparent resin and the Abbe number of the fibrous filler, the higher the refractive index in a wider wavelength region, and the higher the light transmittance in a wide range.

  Examples of the fibrous filler used in the present invention include glass fibers, glass fiber cloths such as glass cloth and glass nonwoven fabric, glass beads, glass flakes, glass powder, and milled glass. Among them, the effect of reducing the linear expansion coefficient is high. Glass fiber cloths such as glass cloth and glass nonwoven fabric are preferred, and glass cloth is most preferred.

  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 fibrous filler is preferably 1 to 90% by weight, more preferably 10 to 80% by weight, and still more preferably 30 to 70% by weight with respect to the transparent substrate. If the blending amount of the fibrous filler is within this range, molding is easy, and the effect of reducing linear expansion due to the composite is recognized.

  There is no limitation on the production method of the transparent substrate of the present invention. 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.

  The transparent substrate of the present invention preferably has a sheet-like substrate shape. The thickness of the substrate is preferably 50 to 2000 μm, more preferably 50 to 1000 μm, and most preferably 50 to 200 μm.

  The transparent base material of the present invention preferably has an average linear expansion coefficient at 30 ° C. to 150 ° C. of 40 ppm or less, more preferably 30 ppm or less, and most preferably 20 ppm or less.

  The second transparent resin used in the optical element of the present invention can be exemplified by the same transparent resin as the above-mentioned transparent substrate, but it is inorganic as long as the linear expansion coefficient of the resin after curing is further reduced so that the transparency is not impaired. It is preferable to add a filler.

  The transparent resin used in the optical element of the present invention is preferably a cured product of a curable resin composition. As the curable resin, a curable monomer having a functional group such as an epoxy group, an acrylic group, an oxetanyl group, or a vinyl ether group. Or an oligomer etc. are mentioned, These resin can be used individually or in mixture suitably. In particular, it is preferable to use an epoxy resin having an alicyclic epoxy group as a main component, and as the alicyclic epoxy resin, an alicyclic epoxy resin having a bisphenol A skeleton or an epoxy resin having a hydrogenated biphenyl skeleton is particularly preferable. .

The curing of the curable resin composition of the optical element used in the present invention is preferably cured using a cationic curing catalyst. Examples of the cationic curing catalyst include those that release a substance that initiates cationic polymerization by heating (for example, an onium salt cationic curing catalyst or an aluminum chelate cationic curing catalyst), and substances that initiate cationic polymerization by active energy rays. What is made to discharge | release (for example, onium salt type | system | group cationic curing catalyst etc.) is mentioned. Among these, it is preferable to perform photocuring by irradiation with ultraviolet rays using a photocationic curing catalyst. Thereby, the hardened | cured material with a smaller volume change rate can be obtained.
Examples of the photocationic curing catalyst include SP170 manufactured by Asahi Denka Kogyo.

  In order to further reduce the linear expansion of the cured resin, it is preferable to add an inorganic filler to the curable resin composition of the optical element used in the present invention as long as the transparency is not impaired.

Examples of the inorganic filler to be added include nanoparticles, nanofibers, and glass beads, and particles having an average dispersed particle diameter of 100 nm or less are preferable. This is because if the particle diameter exceeds the upper limit, scattering at the interface increases if the refractive index of the particles and the resin is different.
However, even if the average dispersed particle system exceeds 100 nm, it can be used if the refractive index of the transparent resin of the transparent resin layer is matched with the refractive index of the inorganic filler. In this case, the refractive index difference between the transparent resin and the inorganic filler is preferably 0.01 or less.
In particular, it is preferable to use nano silica as the inorganic filler.

  In the transparent substrate and optical element of the present invention, an oligomer or a monomer of a thermoplastic resin or a thermosetting resin may be used in combination as long as the characteristics are not impaired. When using these oligomers and monomers, it is necessary to adjust the composition ratio so that the overall refractive index matches the refractive index of the glass filler. Further, if necessary, a small amount of an antioxidant, an ultraviolet absorber and the like may be contained as long as the properties such as transparency and solvent resistance are not impaired.

The method for forming an optical element of the present invention is not particularly limited as long as it is a method capable of forming an optical element. Although there are a hot press molding method, a casting method, an injection method, etc., a photopolymer method (2P method) with a short manufacturing cycle and good shape transferability is preferable. Examples of the optical element include various lenses such as a lenticular lens, a prism lens, a micro lens, and a Fresnel lens.
The optical element is preferably formed on one side of the transparent substrate.

  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.

(Example 1) Hydrogenated biphenyl type alicyclic epoxy resin having a structure of chemical formula (1) on a T glass-based glass cloth (thickness 90 μm, refractive index 1.523, manufactured by Nittobo) (Daicel Chemical Industrial, E- BP) was impregnated with a resin composition in which 100 parts by weight and 1 part by weight of an aromatic sulfonium-based thermal cation catalyst (SI-100L, manufactured by Sanshin Chemical Co., Ltd.) were impregnated and 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, a mold release treatment is performed on the molding surface (stamper) opposite to the cylinder shape, and 100 parts by weight of E-BP, nano-risica sol (manufactured by Fuso Science, Quartron, average particle size 20 nm, solid content 25 wt%) 200 parts by weight Then, after the solvent is volatilized, and after applying a resin composition comprising 3 parts by weight of a photocationic polymerization catalyst (SP-170 manufactured by Asahi Denka), the cleaned surface of the transparent substrate was cleaned by excimer treatment. The sample was placed on the mold so as not to contain air bubbles, and was irradiated with UV light from the transparent substrate side. After the UV light irradiation, the transparent substrate with an optical element released from the mold was further heated at 250 ° C. in a nitrogen atmosphere for 2 hours to obtain a transparent substrate with a lenticular lens.

(Example 2) NE glass glass cloth (thickness 90 μm, refractive index 1.510, manufactured by Nittobo Co., Ltd.) Hydrogenated biphenyl type alicyclic epoxy resin (Daicel Chemical Industrial, E-BP) 70 parts by weight, oxetanyl silicate A resin composition obtained by mixing 30 parts by weight (manufactured by Toagosei Co., Ltd., OXT-191) and 1 part by weight of an aromatic sulfonium-based thermal cation catalyst (SI-100L, manufactured by Sanshin Chemical) was impregnated and degassed. 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, a mold release process was performed on the molding surface (stamper) obtained by cutting a V-shaped groove opposite to the Fresnel lens shape, and a transparent substrate with a Fresnel lens was obtained in the same manner as in Example 1.

(Example 3) NE glass-based glass cloth (thickness 90 μm, refractive index 1.510, manufactured by Nittobo) 70 parts by weight of hydrogenated biphenyl type alicyclic epoxy resin (Daicel Chemical Industrial, E-BP), oxetanyl silicate (Toa Gosei Co., Ltd., OXT-191) 30 parts by weight and an aromatic sulfonium-based thermal cation catalyst (Sanshin Chemical Co., Ltd., SI-100L) mixed with a resin were impregnated and 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, in order to clean only the portion where the microlens is to be processed, a mask processed into a shape for forming the microlens was superimposed on the transparent substrate, and the surface of the transparent substrate was subjected to excimer treatment through the mask. The surface energy of the transparent substrate exposed by the excimer process becomes larger than the masked unexposed surface energy. The resin composition used for the lenticular lens in Example 1 was applied to the excimer-treated surface and heat-treated at 50 ° C. for 5 minutes, so that the microlens-shaped uncured resin composition was made transparent using the surface tension of the resin composition. Formed on a substrate. Next, it was irradiated with UV light and heated at 250 ° C. for 2 hours under a nitrogen atmosphere to obtain a transparent substrate with microlenses.

Comparative Example 1 A PET film was used as a transparent substrate. The mold surface of the mold opposite to the cylinder shape (stamper) is subjected to mold release treatment and mixed with 100 parts by weight of E-BP and 200 parts by weight of nano-risica sol (manufactured by Fuso Science, Quartron, average particle size 20 nm, solid content 25 wt%). Then, after volatilizing the solvent, after applying a resin composition comprising 3 parts by weight of a photocationic polymerization catalyst (SP-170 manufactured by Asahi Denka), the cleaned surface of the PET film whose surface was cleaned by excimer treatment was used as a mold. The film was placed so as not to contain bubbles and irradiated with UV light from the film side. After the UV light irradiation, the transparent substrate with an optical element released from the mold was further heated at 90 ° C. in a nitrogen atmosphere for 5 hours to obtain a PET film with a lenticular lens.

Table 1 shows the compositions and evaluation results of Examples and Comparative Examples. The evaluation method is as follows.
(A) Average linear expansion coefficient Using a TMA / SS6000 type thermal stress strain measuring device manufactured by SEIKO ELECTRONICS CO., LTD. Went. The average linear expansion coefficient from 30 ° C to 150 ° C was calculated.
(B) Refractive index Only the resin composition used for the transparent substrate was cured under the same curing conditions as the transparent substrate, and the refractive index at a wavelength of 598 nm was measured with an Abbe refractometer.

Example 4
A liquid crystal panel that repeatedly displays two parallax images corresponding to two viewpoints for the right eye and the left eye in a horizontal manner in a line shape is arranged on the front of the backlight, and the cylinder shape is on the opposite side of the backlight. A transparent substrate with a lenticular lens produced by the same method as in Example 1 was placed. At this time, similarly to the parallax image of the liquid crystal panel, the cylinder structure is repeatedly arranged in the horizontal direction, and the cycle of the cylinder structure is the same as the pitch when the repetition of the parallax pixels for the right eye and the left eye is one period. I made it.
When the display surface was observed while changing the observation distance from the panel in an environment of 25 ° C., a good three-dimensional display was obtained. Next, an image was similarly observed under an atmosphere of 60 ° C. assuming on-vehicle use, but the stereoscopic image was in a good state.

(Comparative Example 2)
Using the lenticular lens-attached PET film prepared in Comparative Example 1, a stereoscopic image was observed by the same method as in Example 4.
When the display surface was observed while changing the observation distance from the panel in an environment of 25 ° C., a good three-dimensional display was obtained. Next, as a result of similarly observing an image in an atmosphere of 60 ° C. assuming that it is mounted on a vehicle, even if the observation distance from the panel is changed before and after, a stereoscopic image observed at 25 ° C. cannot be obtained, and the display image A decrease was seen.

Claims (9)

An optical sheet in which an optical element mainly composed of a second transparent resin is formed on a transparent substrate made of a first transparent resin and a fibrous filler and having an average linear expansion coefficient at 30 to 150 ° C. of 40 ppm or less. The optical sheet according to claim 1, wherein the optical element is a lenticular lens. The optical sheet according to claim 1, wherein the optical element is a prism lens. The optical sheet according to claim 1, wherein the optical element is a microlens. The optical sheet according to claim 1, wherein the optical element is a Fresnel lens. The first transparent resin or the second transparent resin is obtained by curing a resin composition containing a cationically polymerizable component, and the cationically polymerizable component has one or more epoxy groups. The optical sheet according to claim 1, comprising a compound, a compound having an oxetanyl group, or a compound having a vinyl ether group. The first transparent resin or the second transparent resin is obtained by curing a resin composition containing an alicyclic epoxy resin represented by the chemical formula (1) as a main component. Optical sheet.
The optical sheet according to any one of claims 1 to 7, wherein a difference in refractive index between the first transparent resin and the fibrous filler is 0.01 or less. The optical sheet according to any one of claims 1 to 8, wherein the fibrous filler is a glass fiber cloth.