JP3482815B2 - Transparent conductive sheet - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent conductive sheet used for display elements such as liquid crystal displays, display input / output devices such as touch panels, and solar cell conversion elements.

[0002]

2. Description of the Related Art With the rapid progress of electronics technology, the field of optoelectronics such as liquid crystal display panels, touch panels, and solar cell conversion elements is expanding. In general, optoelectronic devices are used for various purposes by forming the device on a glass substrate having a transparent conductive layer. However, glass has a large weight, and when incorporated in a portable device, there is a problem that the weight of the device becomes large due to the large specific gravity of the glass. Therefore, weight reduction is strongly desired, and plastic sheets have been used instead of glass substrates.

However, the temperature required in the process of forming an optoelectronic element is required to have a heat resistance of about 150 ° C. although it has been lowered by the recent technological development. Therefore, films such as polyarylate, polyether sulfone, and polycarbonate, which are known as heat resistant polymers, have been adopted as substrates. However, since these film substrates at present have a thickness of about 0.1 mm, they lack rigidity as compared with conventional glass substrates, and there is a problem that they cannot be manufactured by a liquid crystal display process using conventional glass substrates.

In order to impart rigidity, it is conceivable to make the film thicker, but in the solvent casting method, the production of a thickness of about 200 μm is practically limited due to problems of foaming, flatness reduction, and residual solvent. In addition, for application to liquid crystal elements, it is necessary that the sheet substrate has a birefringence of 20 nm or less, preferably 10 nm or less. It is difficult to produce a molded body of
In reality, the manufacturing limit is about 100 μm.

Therefore, Japanese Patent Laid-Open No. 7-36023 proposes an optical plastic sheet in which two sheets each having a small birefringence are laminated. However, since such a sheet is made of a thermoplastic resin, it has a high rigidity. It has the drawbacks of being small and of being inferior in chemical resistance. Also,
Such an optical plastic sheet to which conductivity has been imparted requires an etching step of a conductive thin film, a solvent coating step for protective coating, a washing step, etc. at the stage of forming an optoelectronic element, but the sheet itself. Since the chemical resistance is poor, it is necessary to form a conductive film by providing a thin film having chemical resistance on the surface.

On the other hand, Japanese Patent Laid-Open No. 6-116406 proposes an optical film in which a surface layer of a base film is coated with a curable resin. However, since such a film is also swollen and dissolved by the solvent from the side surface of the sheet when the substrate is washed, there is a problem that the chemical resistance is poor and the rigidity of the substrate is not sufficient.

[0007]

In view of the above circumstances, the present invention has excellent chemical resistance required in a manufacturing process of liquid crystal elements, touch panels, and solar cell substrates, and has rigidity equivalent to that of glass substrates. Therefore, it can be shared or compatible with the conventional liquid crystal display process using a glass substrate, and can be used not only for TN liquid crystal display panels but also for STN liquid crystal display panels that require particularly fine surface uniformity. A transparent conductive sheet is provided.

[0008]

The present invention for solving the above problems relates to a transparent conductive sheet comprising a photo-curable resin sheet and a transparent conductive film formed on the surface thereof.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The transparent conductive sheet of the present invention is mainly composed of a photocurable resin sheet and a transparent conductive film. The photocurable resin forming the photocurable resin sheet, which is the main component of the transparent conductive sheet, is a resin that is cured by irradiation with ultraviolet rays or the like. Specifically, a resin composition comprising an acrylate compound having a radical reactive unsaturated compound, a resin composition comprising this acrylate compound and a mercapto compound having a thiol group, epoxy acrylate, urethane acrylate, polyester acrylate, polyether acrylate, etc. Examples thereof include, but are not limited to, a resin composition obtained by melting the oligomer of (1) in a polyfunctional acrylate monomer.

Of these, at least one selected from the sulfur-containing bis (meth) acrylate represented by the formula (1) and the alicyclic skeleton bis (meth) acrylate represented by the formula (2).
A composition composed of one kind of bis (meth) acrylate is preferable in terms of chemical resistance, rigidity and the like. In addition, "(meth) acrylate" is a general term for acrylate or methacrylate.

[0011]

[Chemical 6]

[In the formula (1), R ¹ and R ² may be different from each other and represent a hydrogen atom or a methyl group. R ³ is a hydrocarbon group having 1 to 6 carbon atoms which may have an oxygen atom and / or a sulfur atom in the carbon chain, preferably 2 to 4 carbon atoms.
Is an alkylene group. R ⁴ represents a hydrocarbon group having 1 to 6 carbon atoms, which may have an oxygen atom and / or a sulfur atom in the carbon chain, preferably an alkylene group having 1 to 3 carbon atoms. X represents a halogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and a represents an integer of 0 to 4. However, when a is an integer of 2 or more, a plurality of Xs may be different from each other. ]

Some examples of the compound represented by the formula (1) are as follows. p-bis (β-methacryloyloxyethylthiomethyl) benzene, p-bis (β
-Acryloyloxyethylthiomethyl) benzene, m
-Bis (β-methacryloyloxyethylthiomethyl)
Benzene, m-bis (β-acryloyloxyethylthiomethyl) benzene, p-bis (β-methacryloyloxyethyloxyethylthiomethyl) benzene, p-bis (β-methacryloyloxyethylthioethylthiomethyl) benzene, p- Bis (β-methacryloyloxyethylthiomethyl) tetrabromobenzene, m-bis (β-methacryloyloxyethylthiomethyl) tetrachlorobenzene. These compounds are disclosed, for example, in JP-A-6-63.
It can be synthesized by the method disclosed in JP-A-2-195357.

[0014]

[Chemical 7]

[In the formula (2), R^FiveAnd R⁶Are different from each other
And may represent a hydrogen atom or a methyl group. b is 1
Represents 2 and c represents 0 or 1. ] To illustrate some of the compounds of formula (2),
Is the street. Bis (oxymethyl) tricyclo [5.
2.1.0^{2, 6}] Decane-diacrylate, bis (o
(Xymethyl) tricyclo [5.2.1.0^{2, 6}] Deca
= Dimethacrylate, bis (oxymethyl) trisic
B [5.2.1.0^{2, 6}] Decane = acrylate meta
Acrylate, bis (oxymethyl) pentacyclo [6.
5.1.1^{3, 6}． 0^{2, 7}． 0^{9, 13}] Pentadecane =
Diacrylate, bis (oxymethyl) pentacyclo
[6.5.1.1.^{3, 6}． 0^{2, 7}． 0^{9, 13}] Penta
Decane = dimethacrylate, bis (oxymethyl) pen
Tacyclo [6.5.1.1. ^{3, 6}． 0^{2, 7}． 0^{9, 13}]
Pentadecane = acrylate methacrylate. these
The compound is disclosed in, for example, JP-A-62-225508.
It can be synthesized by the disclosed method.

The (meth) acrylates represented by the above formulas (1) and (2) can be used alone or in combination of two or more kinds. When the compound of formula (1) is used alone, the low birefringence plate obtained by the present invention has a high refractive index of 1.54 to 1.65 at room temperature at the D line of sodium (589.3 mm). Have. When the compound of formula (2) is used alone, the refractive index is relatively low, 1.47 to 1.51. Therefore, by using two or more compounds represented by formulas (1) and (2) in combination, a low birefringence plate having a desired refractive index between 1.47 and 1.65 can be obtained.

The photocurable resin can be used by polymerizing the above bis (meth) acrylate alone.
At least one mercapto compound selected from mercapto compounds having two or more thiol groups in the molecule represented by the following formulas (3), (4) and (5) is bis (meth) acrylate 80-99.1. With respect to parts by weight, 0.
By blending 1 to 20 parts by weight, more preferably 1 to 15 parts by weight, further preferably 5 to 10 parts by weight, birefringence can be reduced and appropriate toughness can be imparted. When the amount of the mercapto compound exceeds 20 parts by weight, the heat resistance becomes low, which is not preferable.

[0018]

[Chemical 8]

[In the formula (3), a plurality of R ^7's may be different from each other and each represents a methylene group or an ethylene group.
R ⁸ represents a hydrocarbon residue having 2 to 15, preferably 2 to 6 carbon atoms, which may contain an oxygen atom and / or a sulfur atom in the carbon chain. d shows the integer of 2-6. ]

That is, the compound represented by the formula (3) is
It is a diester to hexaester of thioglycolic acid or thiopropionic acid and a polyol. Some of them are exemplified by pentaerythritol tetrakis (β-thiopropionate), pentaerythritol tetrakis (thioglycolate), trimethylolpropane tris (β-thiopropionate), trimethylolpropane tris (thioglycolate). , Diethylene glycol bis (β-thiopropionate), diethylene glycol bis (thioglycolate), triethylene glycol bis (β-thiopropionate), triethylene glycol bis (thioglycolate), dipentaerythritol hexakis (β -Thiopropionate), dipentaerythritol hexakis (thioglycolate) and the like.

[0021]

[Chemical 9]

[In the formula (4), Y's may be different from each other, and HS- (CH ₂ ) _e- (CO) (OCH ₂ -C
_{H 2) f - (CH 2} ) g - shows a. However, e is an integer of 1 to 4, f is an integer of 1 to 4, and g is an integer of 0 to 2. ]

That is, the compound of the formula (4) is a ω-SH group-containing triisocyanurate. To illustrate some of them, tris [2- (β-thiopropionyloxy)]
Ethyl] isocyanurate, tris (2-thioglyconyloxyethyl) isocyanurate, tris [2- (β
-Thiopropionyloxyethoxy) ethyl] isocyanurate, tris (2-thioglyconyloxyethoxyethyl) isocyanurate, tris [3- (β-thiopropionyloxy) propyl] isocyanurate, tris (3-thioglyconyloxypropyl) ) Examples include isocyanurate.

[0024]

[Chemical 10]

[In the formula (5), R ⁹ and R ¹⁰ may be different from each other and represent a hydrocarbon group having 1 to 3 carbon atoms. m and n each represent 0 or 1. p represents 1 or 2. That is, the compound of formula (5) is an α, ω-SH group-containing compound. Some examples thereof include benzene dimercaptan, xylylene dimercaptan, and 4,4'-dimercapto diphenyl sulfide.

Other monomers used in the above polymerization of the photocurable resin include, for example, methyl (meth) acrylate, phenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, methacryloyloxy. Methyl tetracyclododecane, methacryloyloxymethyl tetracyclododecene, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2,2-bis [4- (β -Methacryloyloxyethoxy) phenyl] propane, 2,2 '
-(Meth) acrylate compounds such as bis [4- (β-methacryloyloxyethoxy) cyclohexyl] propane, 1,4-bis (methacryloyloxymethyl) cyclohexane, trimethylolpropane tri (meth) acrylate, styrene, chlorostyrene, divinyl Examples include nucleus and / or side chain-substituted and unsubstituted styrene such as benzene and α-methylstyrene. Among these other monomers, methacryloyloxymethylcyclododecane, 2,2-bis [4- (β-methacryloyloxyethoxy) phenyl] propane, 2,2-bis [4- (β
-Methacryloyloxyethoxy) cyclohexyl] propane, 1,4-bis (methacryloyloxymethyl)
Cyclohexane and mixtures thereof are especially preferred.
Further, these may contain a small amount of antioxidants, ultraviolet absorbers, dyes and pigments, fillers and the like.

The above-mentioned bis (meth) acrylate or a mixture of bis (meth) acrylate and a mercapto compound is cured by a known radical polymerization in which a photopolymerization initiator which generates radicals by active energy rays such as ultraviolet rays is added. Let Examples of the photopolymerization initiator used at that time include benzophenone, benzoin methyl ether, benzoin isopropyl ether, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2,6-dimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethyl. Examples thereof include benzoyldiphenylphosphine oxide. Preferred photoinitiators are 2,4,6-trimethylbenzoyldiphenylphosphine oxide and benzophenone. Two or more of these photopolymerization initiators may be used in combination.

The amount of the photopolymerization initiator added is 100
0.01 to 1 part by weight, preferably 0.02 parts by weight
~ 0.3 parts by weight. If the amount of the photopolymerization initiator added is too large, not only the polymerization will proceed rapidly and the birefringence will increase, but also the hue will deteriorate. On the other hand, if the amount is too small, the composition cannot be sufficiently cured.

The amount of active energy rays to be irradiated is arbitrary as long as the photopolymerization initiator generates radicals, but when the amount is extremely small, the heat resistance and mechanical properties of the cured product are poor because the polymerization is incomplete. If it is not sufficiently expressed, on the contrary, if it is extremely excessive, deterioration due to light such as yellowing of the cured product will occur,
Ultraviolet rays of 200 to 400 nm are preferably 0.1 to 20 depending on the composition of the monomer and the kind and amount of the photopolymerization initiator.
Irradiate in the range of 0J. Specific examples of the lamp to be used include a metal halide lamp and a high pressure mercury lamp.

Thermal polymerization may be used in combination for the purpose of promptly completing the curing. That is, the composition and the entire mold are heated in the range of 30 to 300 ° C. simultaneously with the light irradiation. In this case, a radical polymerization initiator may be added in order to complete the polymerization better, but excessive use brings about an increase in birefringence and deterioration in hue. Specific examples of the thermal polymerization initiator include benzoyl peroxide, diisopropyl peroxycarbonate, t-butylperoxy (2-ethylhexanoate) and the like, and the amount used is 1 part by weight or less based on 100 parts by weight of the monomer. Is preferred.

Furthermore, it is possible to reduce the internal strain generated during the completion of the polymerization reaction and the completion of the polymerization reaction by heating the cured product after the radical polymerization by light irradiation. The heating temperature is appropriately selected depending on the composition of the cured product and the glass transition temperature, but excessive heating causes deterioration of the hue of the cured product, so a temperature near the glass transition temperature or lower is preferable.

In the method of molding the photocurable resin sheet, a cavity is formed by a spacer or the like by using two opposing flat plates (hereinafter referred to as "molding dies"), at least one surface of which is transparent to the active energy rays, and the peripheral portion is formed. A photo-curable resin is injected into a sealed injection mold, and active energy rays are irradiated to cure the photo-curable resin. The material of the molding die, from the surface of the sheet after curing, preferably using a polishing glass,
Any material may be used as long as it has sufficient permeability of active energy rays to cure the photocurable resin and does not easily deform its shape by heat or the like. Further, a plastic such as an acrylic plate that can obtain a surface property equivalent to that of polished glass can be used.

If necessary, a release agent or the like may be applied to the mold or a release layer may be provided to make it easier to remove the photocurable resin sheet after curing from the mold. The release agent used, the release layer, and the application thereof are not particularly limited, but it is a substance having sufficient permeability of the active energy ray to cure the photocurable resin, and further cures the photocurable resin. Any substance that does not easily deform its formation state due to active energy rays for that purpose, heat generated during curing, or the like, and that has flatness equivalent to that of the glass surface may be used.

The active energy ray cures the photocurable resin, and examples thereof include ultraviolet rays. The irradiation amount of the active energy ray may be an amount that cures the photocurable resin used. The spacers and the like for forming the cavities are not particularly limited as long as they can obtain a desired sheet thickness. For example, a plate or rod made of rubber such as silicon rubber or a metal, or a plate or rod made of resin such as Teflon can be used. Further, an acrylic resin or the like may be applied as a hard coat layer for preventing scratches on the back surface of the photocurable resin sheet.

The transparent conductive material forming the transparent conductive film which is the other main component of the transparent conductive sheet is as follows.
Indium oxide, tin oxide, gold, silver, copper, nickel and the like can be mentioned, and these can be used alone or in combination of two or more. Of these, usually indium oxide 99
Indium tin oxide (hereinafter referred to as “ITO”) made of a mixture of ˜90% and tin oxide 1 to 10% is particularly preferable from the viewpoint of the balance between transparency and conductivity. As a method for forming the transparent conductive film, a conventionally known vacuum vapor deposition method, sputtering method, ion plating method, chemical vapor deposition method, or the like can be used. Of these, the sputtering method is preferable from the viewpoint of adhesion. The thickness of the transparent conductive film is preferably in the range of 500 to 2000 Å, from the viewpoint of the balance between transparency and conductivity.

The transparent conductive sheet of the present invention has a thickness of 550 nm.
The light transmittance at the wavelength of light is preferably 75% or more, and particularly preferably 80% or more. If the light transmittance is less than 80%, it is difficult to use in a color display or the like because the screen becomes dark, and it tends to be used only for a monochrome display device. The birefringence of the transparent conductive sheet is preferably 20 nm or less, and particularly preferably 10 nm or less. If the display panel is larger than 20 nm,
Color unevenness on the display screen tends to occur.

On the other hand, the thickness of the transparent conductive sheet is 0.1
0 to 2.00 mm is preferable. The transparent conductive sheet has a large bending elastic modulus, but if it is less than 0.10 mm, the sheet is easily bent due to its own weight, and the manufacturing process of a liquid crystal display using a conventional glass substrate tends to be unusable. Conventional 1.5-0.7mm
The weight is the same as that of the glass substrate, which is out of the purpose of weight reduction.

Further, the surface roughness Ra of the transparent conductive sheet is
Is preferably 0.05 μm or less. 0.05
When the thickness exceeds μm, the TN liquid crystal is suitable for use in a display panel, but in the STN liquid crystal display panel, the cell gap cannot be made uniform and display unevenness tends to occur.

The transparent conductive sheet of the present invention is a gas barrier for blocking oxygen and water vapor between the photocurable resin sheet and the transparent conductive film or on the surface of the photocurable resin sheet on which the transparent conductive film is not formed. The layers can be laminated. It is suitable for use as a transparent conductive sheet such as a touch panel without a gas barrier layer, but when used as a liquid crystal display device, a gas barrier layer is laminated in a narrow liquid crystal part for the purpose of preventing bubbles and deterioration of the liquid crystal. Is more preferable. As the gas barrier layer, an ethylene-vinyl alcohol copolymer (for example, Eval, trade name Eval, Soarnol),
Examples thereof include those in which a photocurable resin sheet is coated with vinylidene chloride or the like, and those in which a thin film made of an inorganic oxide is formed on the photocurable resin sheet. As the high-humidity gas barrier layer, a material obtained by vapor-depositing aluminum oxide such as SiOx (X = 1.5 to 2) and alumina alone or as a mixture is particularly preferable from the viewpoint of improving oxygen and water vapor barrier properties. Examples of the method of forming the gas barrier layer include a method of coating a resin and the like, and a method of forming a vapor deposition film made of an inorganic oxide. As a method for forming a vapor deposition film, a vacuum vapor deposition method,
A conventionally known method such as a vacuum sputtering method, an ion plating method or a CVD method can be used. Between the photocurable resin sheet and the gas barrier layer, between the gas barrier layer and the transparent conductive film, and conventionally known undercoating agent for improving the adhesion between the transparent conductive film and the photocurable resin sheet, Also, a top coat agent or the like can be applied and used.

As an application example of the transparent conductive sheet of the present invention, for example, in a liquid crystal display device, a gas barrier layer, a transparent conductive film, an alignment film, on a surface of a transparent substrate made of a pair of photocurable resins, facing each other, An undercoat layer and the like are sequentially formed, and then a liquid crystal material is injected and sealed with a sealing member,
Further, a liquid crystal display element can be formed by laminating a polarizing plate on the outer surface.

Further, in the electroluminescence display device, usually, on the transparent conductive sheet of the present invention,
An example is a structure in which a light emitting layer, an insulating layer, and a back electrode are sequentially formed, and the whole is covered with a gas barrier layer. In this case, zinc sulfide, cadmium sulfide, zinc selenide or the like is used for the light emitting layer, yttrium oxide, thallium oxide, silicon nitride or the like is used for the insulating layer, and aluminum or the like is used for the back electrode.

[0042]

EXAMPLES The contents and effects of the present invention will be described below in more detail with reference to Examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. Moreover, the evaluation of the transparent conductive sheets obtained in Examples and Comparative Examples was measured by the following methods.

<Film Thickness> Regarding the gas barrier thin film and the conductive film of the sheets obtained in Examples and Comparative Examples, the cross section of the sheet was taken with a transmission electron microscope (H-600 manufactured by Hitachi, Ltd.).
And the thickness of the thin film was measured.

<Chemical resistance> After the transparent conductive sheets obtained in Examples and Comparative Examples were immersed in xylene at 25 ° C. for 24 hours, the appearance of the transparent conductive sheet, the peeling of the ITO film and the presence or absence of cracks were examined. It was observed with the naked eye and evaluated as follows. The case where there is no change in appearance is ○, the case where there is a slight change in appearance is △, and the transparent conductive sheet swells, dissolves or I
The case where peeling and cracking of the TO film was significant was marked with x.

<Heat Resistance> In the Bigatt softening test, the measurement conditions were as follows: indenter cross-sectional area 1.0 mm, load 5 kg, heating rate 50 ° C./hr, indenter 0.4 mm or more at 120 ° C. or lower, △: 0.2 to 0.4 mm penetration, ○: 0.1 mm or less and almost no penetration
And

<Birefringence> A birefringence measuring device (ADR100, manufactured by Oak Manufacturing Co., Ltd.) was used to measure the in-plane birefringence at a wavelength of 632.8 nm.

<Deflection> 20 cm × a transparent conductive sheet
A test piece of 5 cm was used, and the deflection distance of the tip from the horizontal plane when the test piece of the deflection amount measuring instrument of FIG.

<Measurement of surface resistance value> The surface resistance value was measured using a 4-terminal method resistance meter (Lorestar MP) manufactured by Mitsubishi Chemical Corporation.

<Light transmittance> Using a spectrophotometer manufactured by Hitachi, Ltd., the transmittance at a wavelength of 550 nm was measured.

<Roughness (Ra) of ITO film surface> Using a surface roughness measuring instrument (Surf Comb 575A manufactured by Tokyo Seimitsu Co., Ltd.), a diamond needle (1 μmR, 90 ° cone), measuring length 0.5 mm The cutoff value was 0.16 mm, the measurement speed was 0.06 mm / sec, and the straight line correction was performed.

Example 1 100 parts by weight of bisoxymethyltricyclo [5.2.1.0 ^2,6 ] decanedimethacrylate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by BASF) as a photoinitiator "Lucirin TPO") 0.
After 0.05 parts by weight and 0.05 parts by weight of benzophenone were uniformly mixed and stirred, the mixture was defoamed to obtain a composition. This composition was poured into a mold of optically polished glass using a silicon plate having a thickness of 1 mm as a spacer, and the output on the glass surface was 80 W /
40 J / on the glass mold surface with a cm metal halide lamp
After irradiating for about 20 minutes so that the energy was cm ^2, the glass mold was released to obtain a photocurable resin sheet having a thickness of about 1000 μm. By the sputtering method on the obtained sheet,
A 1000 Å-thick ITO film was formed to obtain a transparent conductive sheet. The evaluation results are shown in Table-1.

Example 2 96 parts by weight of bisoxymethyltricyclo [5.2.1.0 ^2,6 ] decanedimethacrylate, 4 parts by weight of pentaerythritol tetrakis (β-thioproopionate),
As a photoinitiator, 0.05 parts by weight of 2,4,6-trimethylbenzoyldiphenylphosphine oxide (“Lucirin TPO” manufactured by BASF) and 0.05 parts by weight of benzophenone were uniformly mixed and stirred, and then defoamed to form a composition. I got a thing.
This composition was poured into a mold of optically polished glass using a silicon plate having a thickness of 0.3 mm as a spacer, and a metal halide lamp with an output of 80 W / cm on the glass surface, an energy of 40 J / cm ² was applied to the glass mold surface. Irradiation for about 20 minutes. After irradiation, the glass mold is released, and the thickness is about 3
A photocurable resin sheet of 00 μm was obtained. A 1000 l thick ITO film was formed on the obtained sheet by a sputtering method to obtain a transparent conductive sheet. Table 1 shows the evaluation results.
Shown in.

Example 3 100 parts by weight of p-bis (β-methacryloyloxyethylthiomethyl) benzene, 2,4,6 as a photoinitiator
-0.05 parts by weight of trimethylbenzoyldiphenylphosphine oxide ("Lucirin TPO" manufactured by BASF) and 0.05 parts by weight of benzophenone were uniformly mixed and stirred, and then defoamed to obtain a composition. This composition was poured into a mold of optically polished glass using a silicon plate having a thickness of 0.7 mm as a spacer, and the output on the glass surface was 80 W / cm.
40 J / cm on the glass surface with the metal halide lamp of
Irradiation was performed for about 20 minutes so that the energy became ² . After the irradiation, the glass mold was released to obtain a photocurable resin sheet having a thickness of about 700 μm.

On the obtained sheet, SiO (manufactured by Sumitomo Sitix) was evaporated under a vacuum of 4 × 10 ⁻⁵ Torr by a high frequency induction heating method to form a silicon oxide thin film having a thickness of 350 Å. An ITO film having a thickness of 800 Å was formed on the photocurable resin sheet on which the silicon oxide thin film was not formed by a sputtering method to obtain a transparent conductive sheet. Table of evaluation results
Shown in 1.

[0055] Example 4 bis oxymethyl tricyclo [5.2.1.0 ^{2, 6]} decane dimethacrylate 98 parts by weight, 2 pentaerythritol tetrakis (beta-Chiopu Ropi onato) 2 parts by weight, as a photoinitiator, 4,6-Trimethylbenzoyldiphenylphosphine oxide ("Lucirin T" manufactured by BASF)
PO ") and 0.05 parts by weight of benzophenone were uniformly mixed and stirred, and then defoamed to obtain a composition. This composition was poured into a mold of optically polished glass using a 0.7 mm-thick silicon plate as a spacer, and a metal halide lamp with an output of 80 W / cm on the glass surface was used to apply 40 J / cm ^{2 to} the glass mold surface. About 2 to become energy
Irradiate for 0 minutes. After irradiation, the glass mold is released to a thickness of about 70
A 0 μm photocurable resin sheet was obtained. A 1000 Å thick ITO film was formed on the obtained sheet by a sputtering method to obtain a transparent conductive sheet. Table 1 shows the evaluation results.
Shown in.

[0056] Example 5 bis oxymethyl tricyclo [5.2.1.0 ^{2, 6]} decane dimethacrylate 98 parts by weight, pentaerythritol tetrakis (beta-Chiopu Ropi onato) 2 parts by weight, as a photoinitiator 2, 4,6-Trimethylbenzoyldiphenylphosphine oxide ("Lucirin T" manufactured by BASF)
PO ") and 0.05 parts by weight of benzophenone were uniformly mixed and stirred, and then defoamed to obtain a composition. This composition was poured into a mold of optically polished glass using a 0.7 mm thick silicon plate as a spacer, and a metal halide lamp with an output of 80 W / cm on the glass surface was used to apply 40 J / cm ^{2 to} the glass mold surface. About 2 to become energy
Irradiate for 0 minutes. After irradiation, the glass mold is released to a thickness of about 70
A 0 μm photocurable resin sheet was obtained.

On the obtained sheet, SiO (manufactured by Sumitomo Sitix) was evaporated by a high frequency induction heating system under a vacuum of 3 × 10 ^-5 Torr to form a silicon oxide thin film having a thickness of 350 Å. A thickness of 100 is formed on the thin film surface by a sputtering method.
A 0Å ITO film was formed to obtain a transparent conductive sheet.
The evaluation results are shown in Table-1.

Example 6 70 parts by weight of p-bis (β-methacryloyloxyethylthio) xylylene, 30 parts by weight of pentaerythritol tetrakis (β-thioproopionate), 2,4,6-trimethylbenzoyldiphenylphosphine as a photoinitiator Fin oxide ("Lucirin TPO" manufactured by BASF)
0.05 parts by weight and 0.05 parts by weight of benzophenone were uniformly mixed and stirred, and then defoamed to obtain a composition. This composition was injected into a mold of optically polished glass using a silicon plate having a thickness of 0.7 mm as a spacer, and a metal halide lamp having an output of 80 W / cm on the glass surface and an energy of 40 J / cm ^{2 on} the glass surface. Irradiation for about 20 minutes. After the irradiation, the glass mold was released to obtain a photocurable resin sheet having a thickness of about 700 μm. A 1000 Å thick ITO film was formed on the obtained sheet by a sputtering method to obtain a transparent conductive sheet. The evaluation results are shown in Table-1.

Comparative Example 1 A film of ITO of 1000 Å was formed on a 500 μm Iupilon sheet NF2000 (manufactured by Mitsubishi Engineering Plastics) of polycarbonate-carbonate by a sputtering method. The evaluation results are shown in Table-1.

Example 7 A transparent conductive sheet was prepared in the same manner as in Example 1 except that a photocurable resin sheet having a thickness of 1 mm was obtained by using a polished glass having a surface roughness Ra of 0.003 μm. Got The evaluation results are shown in Table-1. Next, using this transparent conductive sheet, a display panel for TN was prepared by a known method. When the liquid crystal panel thus obtained was lit by transmissive lighting, a panel without display density unevenness was obtained. Further, using this transparent conductive sheet, a display panel for STN was prepared by a known method. When the liquid crystal panel thus obtained was lit and displayed in a transmissive mode, a panel without uneven color density was obtained.

Example 8 A transparent conductive sheet was obtained in the same manner as in Example 4 except that a 1 mm-thick photocurable resin sheet was obtained by using a polished glass having a surface roughness Ra of 0.05 μm. Obtained. The evaluation results are shown in Table-1. Next, using this transparent conductive sheet, a display panel for TN was prepared by a known method. When the liquid crystal panel thus obtained was lit by transmissive lighting, a panel without display density unevenness was obtained. Further, using this transparent conductive sheet, a display panel for STN was prepared by a known method. When the obtained liquid crystal panel was transmissively lit, slight color density unevenness was observed on the screen.

[0062]

[Table 1]

[0063]

INDUSTRIAL APPLICABILITY The transparent conductive sheet of the present invention has excellent chemical resistance and rigidity, and it is possible to use a glass substrate process in manufacturing a liquid crystal display, and the substrate has excellent chemical resistance. Since it does not cause peeling or cracking of the transparent conductive film, it has a special advantageous effect that it is lighter than the one using a glass substrate and has excellent impact resistance, and its industrial utility value is extremely high. Is large.

[Brief description of drawings]

FIG. 1 is a side view of a deflection amount measuring instrument according to an embodiment.

[Explanation of symbols]

1 test piece 2 Holding bracket 3 Support stand 4 substrates S deflection amount

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C08F 20/38 C08F 20/38 290/06 290/06 299/02 299/02 G02F 1/1343 G02F 1/1343 1/135 1 / 135 H01B 5/14 H01B 5/14 A (58) Fields investigated (Int.Cl. ⁷ , DB name) B32B 1/00-35/00 H01B 5/00-5/16 C08F 2/00

Claims (8)

(57) [Claims] 1. A surface of a photocurable resin sheet, which is formed by curing a composition containing at least one bis (meth) acrylate selected from the following formulas (1) and (2) by curing with active energy rays. A transparent conductive sheet, comprising a transparent conductive film formed on a transparent conductive sheet. [Chemical 1] [In the formula (1), R ¹ and R ² may be different from each other,
Indicates a hydrogen atom or a methyl group. R ³ and R ⁴ may be different from each other and represent a hydrocarbon group having 1 to 6 carbon atoms, which may have an oxygen atom and / or a sulfur atom in the carbon chain.
X represents a substituent selected from a halogen atom, an alkyl group having 1 to 6 carbon atoms and an alkoxy group having 1 to 6 carbon atoms, and a
Represents an integer of 0 to 4. However, when a is an integer of 2 or more, a plurality of Xs may be different from each other. ] [Chemical 2] [In the formula (2), R ⁵ and R ⁶ may be different from each other,
Indicates a hydrogen atom or a methyl group. b represents 1 or 2, and c
Indicates 0 or 1. ] 2. A photocurable resin sheet comprising 80 to 99.9 parts by weight of at least one bis (meth) acrylate selected from the formulas (1) and (2) and the following formulas (3) and (4).
And a sheet formed by curing a composition containing 0.1 to 20 parts by weight of at least one mercapto compound selected from (5) and curing the composition with active energy rays. The transparent conductive sheet described. [Chemical 3] [In the formula (3), plural R ^7's may be different from each other and each represents a methylene group or an ethylene group. R ⁸ represents a hydrocarbon residue having 2 to 15 carbon atoms, which may contain an oxygen atom and / or a sulfur atom in the carbon chain. d shows the integer of 2-6. ] [Chemical 4] [In the formula (4), Y may be different from each other, and HS- (C
_{H 2) e - (CO)} (OCH 2 -CH 2) f - (CH 2) g -
Indicates. However, e is an integer of 1-4, f is an integer of 1-4, and g
Represents an integer of 0 to 2, respectively. ] [Chemical 5] [In the formula (5), R ⁹ and R ¹⁰ may be different from each other and represent a hydrocarbon group having 1 to 3 carbon atoms, and m and n each represent 0 or 1. p represents 1 or 2. ] 3. The transparent conductive sheet according to claim 1, wherein the transparent conductive film is indium tin oxide. 4. The transparent conductive sheet according to claim 1, which has a light transmittance at 550 nm of 75% or more. 5. The transparent conductive sheet according to claim 1, which has a birefringence of 20 nm or less. 6. The transparent conductive sheet according to claim 1, wherein the transparent conductive sheet has a thickness of 0.1 to 2.0 mm. 7. The transparent conductive sheet according to claim 1, wherein the surface roughness Ra of the conductive film is 0.05 μm or more. 8. A photocurable resin sheet and a transparent conductive film
Or do not form the transparent conductive film of the photocurable resin sheet
A gas barrier layer is laminated on the surface.
The transparent conductive sheet according to claim 1.
To.