TW201523382A - Layered body - Google Patents

Abstract

Provided is a layered body provided with a prescribed transparent conductive layer for imparting a tactile feedback effect, said layered body being capable of contributing to the enhancement of visibility through a polarized lens if the layered body is applied to an image display device provided with a polarizing plate. A layered body according to the present invention is provided with a retardation layer and a transparent conductive layer provided on one side or both sides of the retardation layer. The front retardation of the retardation layer for a wavelength of 590 nm is at least 3500 nm. The surface resistance of the transparent conductive layer is greater than 103 [Omega]/sq and less than or equal to 1012 [Omega]/sq.

Description

Laminated body

The present invention relates to a laminate.

In recent years, a touch panel has been frequently used as an input device, and as the touch panel, a touch panel that is operable by direct touch with a finger is known. Generally, the operation of the touch panel touches the operation of a flat and smooth operation surface, so that a sense of input like a keyboard input device cannot be obtained. Therefore, research has been conducted on a technique of introducing a so-called tactile feedback sensor into a touch panel, which is used to feedback the tactile sensation when the operator touches the operation surface. For example, a touch panel that vibrates the operation surface when the operator touches is practical. Further, as a technique for imparting a sense of touch to a mode in which vibration is more varied, a technique of controlling the electric charge on the operation surface of the touch panel and imparting a tactile sensation to the operator by electrical feeling has been proposed (for example, Patent Document 1).

On the other hand, the touch panel having the above-described haptic feedback function can be applied to an image display device including a polarizing plate such as a liquid crystal display device. In an image display device including a polarizing plate, when a display screen is viewed through a polarizing lens such as polarized sunglasses, there is a problem that an image cannot be visually recognized or color unevenness is recognized.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-087359

The present invention has been made to solve the above problems, and an object of the invention is to provide a laminated body which is provided with a specific transparent conductive layer for imparting a tactile feedback function, and is applied to an image display device having a polarizing plate. Can help improve the visibility across the polarizing lens.

The laminate of the present invention comprises a retardation layer and a transparent conductive layer disposed on one side or both sides of the retardation layer, and the retardation layer has a front phase difference of 3500 nm or more at a wavelength of 590 nm, and the surface of the transparent conductive layer The resistance value is greater than 10 ³ Ω/□ and is 10 ¹² Ω/□ or less.

In one embodiment, the transparent conductive layer comprises a conductive polymer.

In one embodiment, the conductive polymer is selected from the group consisting of a polyacetylene polymer, a polyparaphenylene polymer, a polyaniline polymer, a polythiophene polymer, a polyparaphenylene vinylene polymer, and a poly At least one of the group consisting of pyrrole polymers.

In one embodiment, the laminate of the present invention further includes a hard coat layer disposed on a side of the transparent conductive layer opposite to the retardation layer.

In one embodiment, the laminate of the present invention further includes an adhesive layer disposed on the outermost side.

In one embodiment, the laminate of the present invention includes the above-described adhesive layer, the retardation layer, the transparent conductive layer, and the hard coat layer in this order.

According to the present invention, a laminate body having a phase difference layer having a specific frontal phase difference and a transparent conductive layer having a specific surface resistance value can be obtained, which is applied to a touch panel having a tactile feedback sensor and In the case of a display device of a polarizing plate, it is possible to contribute to improvement in visibility by a polarizing lens.

10‧‧‧ phase difference layer

20‧‧‧Transparent conductive layer

30‧‧‧hard coating

40‧‧‧Adhesive layer

100‧‧‧Tactile feedback sensor

110, 110'‧‧ ‧ laminated body

120‧‧‧Insulation

200‧‧‧ touch sensor

210‧‧‧1st transparent electrode

220‧‧‧2nd transparent electrode

230‧‧‧Insulation film

300‧‧‧ touch panel

400‧‧‧LCD panel

410‧‧‧Polar plate

410'‧‧‧ Back side polarizer

420‧‧‧Liquid Crystal Unit

500‧‧‧Liquid crystal display device

Fig. 1 is a schematic cross-sectional view showing a laminated body according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view showing a laminated body according to another embodiment of the present invention.

Fig. 3 is a schematic cross-sectional view showing a laminated body according to still another embodiment of the present invention.

Fig. 4 is a schematic cross-sectional view showing an example of a liquid crystal display device using the laminate of the present invention.

A. Laminate

Fig. 1 is a schematic cross-sectional view showing a laminated body according to an embodiment of the present invention. As shown in FIG. 1, the laminated body 110 of the present invention includes a retardation layer 10 and a transparent conductive layer 20 disposed on one side or both sides (one side in the illustrated example) of the retardation layer 10. The phase difference layer may be a single layer or a multiple layer. The single-layer phase difference layer may be composed of one retardation film. The phase difference layer of the complex layer is composed of a plurality of retardation films. In the case of using a plurality of retardation films, the same retardation film may be used, or a different retardation film may be used. The laminated system of the present invention is applied to, for example, an image display device including a polarizing plate. More specifically, the laminated body of the present invention can be used as a component of a tactile feedback sensor, preferably in an image display device having a polarizing plate and a touch panel, and used as a tactile feedback included in the touch panel. The component of the sensor. In addition, the haptic feedback sensor refers to a sensor that is included in the touch panel and is used to feedback the touch panel when the operator touches the touch panel.

Fig. 2 is a schematic cross-sectional view showing a laminated body according to another embodiment of the present invention. The laminated body 110' shown in FIG. 2 is further provided with a hard coat layer 30. Preferably, the hard coat layer 30 is disposed on the opposite side of the transparent conductive layer 20 from the phase difference layer 10.

In still another embodiment, the laminate of the present invention further includes an adhesive layer. The adhesive layer may be disposed on the outermost side of the laminate. For example, the laminate of the present invention may be provided with an adhesive layer, a retardation layer, and a transparent conductive layer in this order. Further, when a hard coat layer is provided, the laminate of the present invention may have, for example, an adhesive layer 40, a retardation layer 10, a transparent conductive layer 20, and a hard coat layer 30 as shown in FIG.

The total light transmittance of the laminate of the present invention is preferably 80% or more, more preferably 85%. On the top, especially good is more than 90%.

A-1. Phase difference layer

The front surface retardation R ₀ of the retardation layer at a wavelength of 590 nm is 3,500 nm or more, preferably 4,000 nm or more, more preferably 5,000 nm to 20,000 nm, and still more preferably 6000 nm to 15,000 nm. If the front phase difference R ₀ is in the above range, the refractive index of the light transmitted through the polarizing plate can be reduced when applied to an image display device having a touch panel and a polarizing plate having a tactile feedback sensor. A layered body that is affected by the wavelength dependence. Such a laminate can contribute to improvement in visibility in the above-described image display device with a polarizing lens interposed therebetween. More specifically, when the laminated body of the present invention is used, it is possible to provide an image display device in which it is difficult to visually recognize an unnecessary coloring or color unevenness even when a polarizing lens is interposed. In the present specification, the front surface retardation R _{0 is} set to be nx at 23 ° C in a direction in which the refractive index in the plane is maximized (that is, in the direction of the slow axis), and the in-plane is The refractive index of the direction in which the slow axis is orthogonal (that is, the direction of the phase axis) is ny, and when the thickness of the phase difference film is d (nm), it is obtained by R ₀ = (nx - ny) × d .

The thickness of the retardation layer is preferably 500 μm or less, more preferably 10 μm to 400 μm, still more preferably 10 μm to 300 μm. If it is in the above range, it is possible to obtain a laminate which does not interfere with the responsiveness of the touch panel when applied to a touch panel.

The total light transmittance of the retardation layer is preferably 80% or more, more preferably 85% or more, still more preferably 90% or more.

The specific retardation layer has a specific dielectric constant of 2 to 5, more preferably 2 to 4. When the dielectric constant of the phase difference layer is in the above range, the function of the haptic feedback sensor which can contribute to the use of electrical action can be obtained by combining with the transparent conductive layer described below (specifically, the improvement of the tactile sensitivity) The layered body. Further, the dielectric constant can be measured by a trade name "4294A Precision Impedance Analyzer" (measuring frequency: 100 kHz) manufactured by Agilent.

The elastic modulus of the retardation layer at 25 ° C is preferably 1 GPa to 10 GPa, more preferably It is 2 GPa to 9 GPa, and more preferably 3 GPa to 8 GPa. If it is in the above range, it is possible to obtain a laminate which can withstand the pressing force at the time of operation and which can achieve good responsiveness when applied to a touch panel. Further, the above-mentioned elastic modulus can be measured by an electronic tensile tester (for example, the product name "Autograph AG-IS" manufactured by Shimadzu Corporation), and based on a stress-strain curve when a tensile load is applied to the measurement sample up to 20 N. The measurement was carried out.

The retardation film constituting the retardation layer described above can be formed of any appropriate material as long as the effect of the present invention can be obtained. A representative example is a stretch film of a polymer film. Examples of the resin forming the polymer film include a polyester resin, an acetate resin, a polyether oxime resin, a polycarbonate resin, a polyamide resin, a polyimide resin, and a polyolefin. Resin, (meth)acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, polyarylate resin, polyphenylene sulfide resin, etc. . It is preferable to use a polyester resin as the resin for forming the polymer film, and it is more preferable to use polyethylene terephthalate as the resin for forming the polymer film. When polyethylene terephthalate is used, a retardation film excellent in strength and light transmittance can be formed at low cost. Moreover, even if the thickness is made thin, a large front phase difference can be obtained, and thus it is possible to obtain a laminated body which does not interfere with the responsiveness of the touch panel when applied to a touch panel.

The above polymer film can be stretched to form a retardation film. The stretching ratio and the extension temperature of the polymer film can be adjusted, and the front phase difference and the phase difference in the thickness direction of the retardation film are controlled.

The stretching ratio may be based on a front phase difference required for the retardation film, a phase difference in the thickness direction, a thickness required for the retardation film, a kind of the resin to be used, a thickness of the polymer film to be used, and an extension temperature, and the like. And change appropriately. Specifically, the stretching ratio is preferably from 1.1 to 6 times, more preferably from 1.1 to 5 times, still more preferably from 2 to 5 times.

The extension temperature may be based on the front phase difference required for the retardation film, the phase difference in the thickness direction, the thickness required for the retardation film, the kind of the resin to be used, the thickness of the polymer film to be used, and the stretching ratio, and the like. And change appropriately. Specifically, the extension temperature is preferably 100 ° C ~ 250 ° C, more preferably 105 ° C ~ 240 ° C, and further preferably 110 ° C ~ 240 ° C.

Regarding the stretching method, any appropriate method can be employed as long as the optical characteristics and thickness as described above can be obtained. As a specific example, a free end extension and a fixed end extension are mentioned. It is preferred to use a free end uniaxial extension, and it is preferred to use a free end longitudinal uniaxial extension.

The retardation film may further contain any appropriate additives as needed. Specific examples of the additive include a plasticizer, a heat stabilizer, a light stabilizer, a lubricant, an antioxidant, an ultraviolet absorber, a flame retardant, a colorant, an antistatic agent, a compatibilizing agent, and a crosslinking agent. And tackifiers, etc. The type and amount of the additive to be used may be appropriately set depending on the purpose.

Various surface treatments may be performed on the phase difference layer as needed. The surface treatment is carried out according to the purpose by any appropriate method. For example, low pressure plasma treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment can be mentioned. In one embodiment, the phase difference layer is surface-treated to hydrophilize the surface of the phase difference layer. When the phase difference layer is hydrophilized, the workability is excellent when a conductive composition prepared by an aqueous solvent (see below) is applied. Further, a laminate having excellent adhesion between the retardation layer and the transparent conductive layer can be obtained.

A-2. Transparent conductive layer

The transparent conductive layer preferably contains a conductive polymer. When a transparent conductive layer is formed using a conductive polymer, a laminate having a desired surface resistivity can be formed. The transparent conductive layer containing a conductive polymer can be formed, for example, by applying a conductive composition containing a conductive polymer to the retardation layer.

The transparent conductive layer has a surface resistivity of more than 10 ³ Ω/□ and is 10 ¹² Ω/□ or less, preferably 10 ⁴ Ω/□ 10 ¹⁰ Ω/□, more preferably 10 ⁵ Ω/□ 10 ^{10 10} Ω. /□, especially good is 10 ⁶ Ω/□~10 ⁹ Ω/□. If it is in the above range, it is possible to obtain a laminate which can appropriately inject and discharge electric charges, and which can impart an appropriate function (for example, responsiveness, diversity of feeling, etc.) to the tactile feedback sensor using electrical action. Moreover, when the surface resistivity of the transparent conductive layer is in the above range, when the haptic feedback sensor including the laminated body is applied to the touch panel, the touch sensor of the touch panel is suppressed from being generated. No electrical influence is required. The surface resistivity of the transparent conductive layer can be adjusted according to the composition of the above conductive composition, the thickness of the transparent conductive layer, and the like.

The thickness of the transparent conductive layer is preferably from 1 nm to 500 nm, more preferably from 1 nm to 400 nm, still more preferably from 1 nm to 300 nm. If it is in the above range, a transparent conductive layer which can well inject and discharge charges is formed. Further, when the laminate having the transparent conductive layer having the above thickness is applied to an image display device including a polarizing plate, it can contribute to improvement in visibility of the polarizing lens.

The total light transmittance of the transparent conductive layer is preferably 80% or more, more preferably 85% or more, still more preferably 90% or more.

Examples of the conductive polymer contained in the conductive composition include a polyacetylene polymer, a polyparaphenylene polymer, a polyaniline polymer, a polythiophene polymer, and a polyparaphenylene group. A polymer, a polypyrrole polymer, a polyphenylene polymer, a polyester polymer modified with an acrylic polymer, and the like. Preferably, the transparent conductive layer comprises a material selected from the group consisting of a polyacetylene polymer, a polyparaphenylene polymer, a polyaniline polymer, a polythiophene polymer, a polyparaphenylene vinylene polymer, and a polypyrrole polymer. One or more polymers in the group.

More preferably, a polythiophene-based polymer is used as the above-mentioned conductive polymer. When a polythiophene type polymer is used, a transparent conductive layer excellent in transparency and chemical stability can be formed. Specific examples of the polythiophene-based polymer include polythiophene; poly(3-C _1-8 alkyl-thiophene) such as poly(3-hexylthiophene); and poly(3,4-ethylenedioxythiophene). Poly(3,4-propanedioxythiophene), poly[3,4-(1,2-cyclohexyl)dioxythiophene] and the like poly(3,4-extended (cyclo)alkyldioxy Thiophene); polythiophene acetylene and the like.

Preferably, the conductive polymer is polymerized in the presence of an anionic polymer. For example, the polythiophene-based polymer is preferably oxidatively polymerized in the presence of an anionic polymer. The anionic polymer may, for example, be a polymer having a carboxyl group, a sulfonic acid group, or a salt thereof. It is preferred to use an anionic polymer having a sulfonic acid group such as polystyrenesulfonic acid.

The conductive polymer, the transparent conductive layer containing the conductive polymer, and the method of forming the transparent conductive layer are described in, for example, Japanese Patent Laid-Open No. 2011-175601, which is incorporated herein by reference. .

The transparent conductive layer can be formed by any suitable method. The transparent conductive layer can be formed, for example, by applying a conductive composition to the retardation layer. The conductive composition contains, for example, the above-mentioned conductive polymer and any suitable solvent (for example, water), and a dispersion of the conductive polymer is dispersed in the solvent. The dispersion concentration of the conductive polymer in the dispersion is preferably from 0.01% by weight to 50% by weight, more preferably from 0.01% by weight to 30% by weight.

Any suitable method can be employed as the coating method of the above conductive composition. For example, a bar coating method, a roll coating method, a gravure coating method, a bar coating method, a slit coating method, a curtain coating method, a spray coating method, and a corner wheel coating method are mentioned. Bufa. The drying temperature is, for example, 50 ° C or higher, preferably 90 ° C or higher, and more preferably 110 ° C or higher. The drying temperature is preferably 200 ° C or lower, and more preferably 180 ° C or lower. The drying time is preferably from 1 minute to 1 hour, more preferably from 1 minute to 30 minutes, and still more preferably from 1 minute to 10 minutes.

The above conductive composition may further contain any appropriate additives as needed. Specific examples of the additive include a dispersion stabilizer, a surfactant, an antifoaming agent, and the like. The type and amount of the additive to be used may be appropriately set depending on the purpose.

A-3. Hard coating

The hard coat layer has a function of imparting chemical resistance, scratch resistance, surface smoothness, and the like to the laminate.

As the material constituting the above hard coat layer, any appropriate material can be employed. Examples of the material constituting the hard coat layer include an epoxy resin, an acrylic resin, a polyoxymethylene resin, an urethane acrylate resin, and the like. Among them, an acrylic resin can be preferably used in terms of easily forming a hard coat layer having a high hardness. The hard coat layer may, for example, be coated with a composition for forming a hard coat layer comprising the resin or the resin precursor (monomer, oligomer), and the hard coat layer may be formed by heat or active energy rays. The composition is obtained by hardening.

The thickness of the hard coat layer can be set to any appropriate thickness depending on the application. The thickness of the hard coat layer is, for example, 2 μm to 20 μm.

The above composition for forming a hard coat layer may further contain any appropriate additives. Examples of the additive include a polymerization initiator, an antifouling agent, a leveling agent, an antiblocking agent, a dispersion stabilizer, a thixotropic agent, an antioxidant, an ultraviolet absorber, an antifoaming agent, a tackifier, and a dispersing agent. , surfactants, catalysts, fillers, lubricants, antistatic agents, etc.

A-4. Adhesive layer

The above adhesive layer is formed using any suitable adhesive. In one embodiment, the adhesive includes an adhesive resin, and examples of the resin include an acrylic resin, an urethane-based resin, a urethane-based resin, and a polyfluorene-based resin. Among them, an acrylic adhesive containing an acrylic resin is preferred.

The above adhesive may further comprise any suitable additive as needed. Examples of the additive include a crosslinking agent, an adhesion-imparting agent, a plasticizer, a pigment, a dye, a filler, an anti-aging agent, a conductive material, an ultraviolet absorber, a light stabilizer, a peeling adjuster, a softener, and an interface. Active agent, flame retardant, antioxidant, and the like. Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, a peroxide crosslinking agent, a melamine crosslinking agent, a urea crosslinking agent, and a metal alkoxide crosslinking agent. a metal chelate crosslinking agent, a metal ruthenium crosslinking agent, a carbodiimide crosslinking agent, An oxazoline crosslinking agent, an aziridine crosslinking agent, an amine crosslinking agent, and the like.

The thickness of the above adhesive layer is preferably from 5 μm to 100 μm, more preferably from 10 μm to 50 μm.

B. Tactile feedback sensor

The laminate of the present invention can be used in a tactile feedback sensor. Practically, the above tactile feedback The feed sensor may have any suitable member in addition to the above-mentioned laminated body. The haptic feedback sensor further includes, for example, an insulating layer, a protective layer, or the like provided on the viewing side of the laminated body (the side of the transparent conductive layer opposite to the phase difference layer or the side of the hard coat layer opposite to the transparent conductive layer) Other layers, control units that sense contact and control charge, and the like. Preferably, the haptic feedback sensor is disposed on the viewing side (operation surface side) of the touch panel including the touch sensor, and more preferably on the transparent conductive layer side of the laminated body (in the form of FIGS. 2 and 3) The hard coating side is provided on the viewing side of the touch panel for the viewing side. The control unit controls the energization of the electrodes of the touch sensor to induce the charge of the laminated body. The operator who touches the haptic feedback sensor senses the tactile sensation such as unevenness by the strength of the electrostatic force of the electric charge. In addition, the details of the haptic feedback sensor are described in Japanese Laid-Open Patent Publication No. 2009-087359, which is incorporated herein by reference.

In the haptic feedback sensor, the transparent conductive layer of the above laminated body has a function of accumulating charges induced as described above. The insulating layer has a function of preventing direct current flow to the operator based on the electric charge accumulated in the transparent conductive layer. The protective layer has a function of imparting antifouling, water repellency, and the like to the tactile feedback sensor. The insulating layer and the protective layer may in turn have the function of another layer. For example, the insulating layer can have a protective function in addition to the insulating function.

As the material constituting the insulating layer, any suitable material can be used as long as it has insulating properties and light transmittance. For example, a resin material such as an acrylic resin can be used. The thickness of the insulating layer can be set to any appropriate thickness depending on the application.

As the material for forming the above protective layer, any appropriate material can be employed. Examples of the material constituting the protective layer include an epoxy resin, an acrylic resin, a polyoxymethylene resin, and a mixture thereof. The thickness of the protective layer can be set to any appropriate thickness depending on the application.

The other layers described above may be laminated via any suitable adhesive or adhesive.

C. Touch panel

In one embodiment, a touch panel having the above-described haptic feedback sensor can be provided. The touch panel is provided with a touch sensor and the above-mentioned tactile feedback sensor disposed on the touch sensor. The configuration method of the haptic feedback sensor is as described in item B above.

As the touch sensor, any suitable touch sensor can be used, and examples thereof include a resistive film type touch sensor, an electrostatic capacitance type touch sensor, and the like. It is preferable to use an electrostatic capacitance type touch sensor. The electrostatic capacitance type touch sensor includes, for example, a pair of any suitable electrodes (for example, ITO (Indium Tin Oxides) electrodes), and any appropriate one disposed between the pair of electrodes. Insulating film. The above touch sensor can further have any suitable components. For example, a cover sheet for protecting the touch sensor may be disposed on the outer side of the touch sensor, that is, between the touch sensor and the haptic feedback sensor. Moreover, the touch sensor can further comprise any suitable optical film.

D. Image display device

In one embodiment, an image display device including the touch panel described above can be provided. The image display device includes the above touch panel and a polarizing plate. Examples of such an image display device include a liquid crystal display device, an organic EL display device, and the like.

The image display device of the present invention may include any suitable member in addition to the touch panel and the polarizing plate. A specific example of the image display device of the present invention is a liquid crystal display device shown in a schematic cross-sectional view of Fig. 4 . The liquid crystal display device 500 includes a touch panel 300 and a liquid crystal panel 400. The touch panel 300 is disposed on the viewing side of the liquid crystal panel 400.

The touch panel 300 includes the above-described haptic feedback sensor 100 and the touch sensor 200 , and the touch sensor 200 is disposed on the liquid crystal panel 400 side. The haptic feedback sensor 100 includes the above-described laminated body (the laminated body 110 in the illustrated example). The haptic feedback sensor 100 further includes various other layers as described in the above item B. In addition, FIG. 4 shows a tactile feedback sensor including the laminated body 110 and the insulating layer 120 as a representative example. The haptic feedback sensor 100 arranges the laminated body 110 on the side of the touch sensor 200. The touch sensor 200 includes a first transparent electrode 210, a second transparent electrode 220, and an insulating film 230 disposed between the first transparent electrode 210 and the second transparent electrode 220. The touch panel 300 and the touch sensor 200 may have any suitable members in addition to the members shown in the drawings.

The liquid crystal panel 400 is representatively provided with two polarizing plates (the viewing side polarizing plate 410 and the back side polarizing plate 410') and the liquid crystal cell 420 disposed between the two polarizing plates. Any suitable one can be used as the polarizing plate and the liquid crystal cell. The liquid crystal panel 400 may have any suitable member in addition to the members shown in the drawings.

In one embodiment, the angle formed by the absorption axis of the viewing-side polarizing plate of the image display device and the retardation axis of the phase difference layer provided in the laminated body is preferably 30° to 60°, more preferably 35 ° ~ 55 °, and further preferably 43 ° ~ 47 °.

According to the present invention, it is possible to provide an image display device to which a tactile feedback function is provided by using the above laminated body, a tactile feedback sensor including the laminated body, and a touch panel including the tactile feedback sensor. Moreover, by using the above laminated body, it is possible to provide an image display device which is excellent in visibility even though a polarizing plate is provided despite having a polarizing plate.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by the examples. The evaluation methods in the examples are as follows. In addition, the thickness was measured using the PEACOCK precision measuring machine digital meter "DG-205" manufactured by Ozaki Manufacturing Co., Ltd.

(1) Phase difference

The phase difference value of the phase difference layer was measured using the trade name "KOBRA-WRP" manufactured by Oji Scientific Instruments Co., Ltd. The measurement temperature was set to 23 ° C, and the measurement wavelength was set to 590 nm.

(2) Surface resistance value

The surface resistance value of the obtained laminate was measured by a four-terminal method using the trade name "Hiresta UP MCP-HT450" manufactured by Mitsubishi Chemical Corporation ANALYTECH. The measurement temperature was set to 23 °C.

(3) Total light transmittance

The total light transmittance of the obtained laminate was measured at room temperature using the trade name "HR-100" manufactured by Murakami Color Research Institute. Furthermore, each was measured three times, and the average value was made into the measured value.

(4) Visibility through a polarizing lens

A polarizing plate (manufactured by Nitto Denko Corporation, trade name "NPF-SEG1425DU") is disposed on the backlight device, and the obtained laminate is formed such that the angle between the absorption axis of the polarizing plate and the retardation axis of the retardation layer is 45°. It is disposed on the polarizing plate. Thereafter, the colorless light that has passed through the laminated body is visually recognized through the polarizing lens.

[Example 1]

A PET (Polyethylene terephthalate) film (manufactured by Mitsubishi Plastics Co., Ltd., trade name "DIAFOIL T602E25") was used as a retardation film using an optical adhesive (thickness: 23 μm). 1238 nm, thickness: 23 μm) was bonded to form a retardation layer. The retardation layer had a front phase difference of 3946 nm and a thickness of 115 μm.

PEDOT/PSS dispersion (manufactured by Heraeus, trade name "Clevios FE-T"; dispersion of conductive polymer containing polyethylene dioxythiophene and polystyrene sulfonic acid; dispersed in 95 parts by weight of pure water; A conductive composition was prepared by dispersing a conductive polymer in a liquid at a concentration of 4% by weight based on 5 parts by weight.

The obtained conductive composition was applied onto the retardation layer at 120 ° C using a bar coater (manufactured by First Science Co., Ltd., product name "Bar coater No. 05"). The air dryer was dried for 2 minutes to form a conductive layer having a thickness of 240 nm.

As described above, a laminate in which a transparent conductive layer is formed on the phase difference layer is obtained. The laminate had a surface resistance value of 3.41 × 10 ⁶ Ω/□ and a total light transmittance of 89.4%. As shown in (4) above, when the polarizing lens is viewed through a polarizing lens, when the absorption axis of the polarizing element of the polarizing plate on the backlight device is orthogonal to the absorption axis of the polarizing lens, the transmitted light can be normally visually recognized. Uncolored transmitted light.

[Embodiment 2]

Seven sheets of a PET film (manufactured by Mitsubishi Plastics Co., Ltd., trade name "DIAFOIL T602E25") as a retardation film were laminated to form a retardation layer (front surface retardation: 8726 nm, thickness: 299 μm), and other examples were used. In the same manner, a laminate having a transparent conductive layer formed on the retardation layer is obtained.

The laminate had a surface resistance value of 2.12 × 10 ⁶ Ω/□ and a total light transmittance of 86.6%. As shown in (4) above, when the polarizing lens is viewed through a polarizing lens, when the absorption axis of the polarizing element of the polarizing plate on the backlight device is orthogonal to the absorption axis of the polarizing lens, the transmitted light can be normally visually recognized. Uncolored transmitted light.

[Example 3]

10 sheets of a PET film (manufactured by Mitsubishi Plastics Co., Ltd., trade name "DIAFOIL T602E25") as a retardation film were laminated to form a retardation layer (front surface retardation: 13130 nm, thickness: 437 μm), and other examples were used. In the same manner, a laminate having a transparent conductive layer formed on the retardation layer is obtained.

The laminate had a surface resistance value of 3.45 × 10 ⁶ Ω/□ and a total light transmittance of 78.5%. As shown in (4) above, when the polarizing lens is viewed through a polarizing lens, when the absorption axis of the polarizing element of the polarizing plate on the backlight device is orthogonal to the absorption axis of the polarizing lens, the transmitted light can be normally visually recognized. Uncolored transmitted light.

[Example 4]

50 parts by weight of an acrylic resin (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat #300", a condensate of pentaerythritol and acrylic acid), and an ultraviolet curable resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Purple UV 1700TL") Acrylamine 50 parts by weight of a urethane-based ultraviolet curable resin), an antifouling material (manufactured by Daikin Industries, Ltd., trade name "DACHP"), 0.5 parts by weight, and a photopolymerization initiator (manufactured by Ciba Japan Co., Ltd.) 3 parts by weight of Irgacure 907") was mixed, and a hard coating layer was prepared by diluting with a mixed solvent of methyl isobutyl ketone: isopropyl alcohol = 1:1 (weight ratio) so that the solid content concentration was 30% by weight. A composition for forming.

A transparent conductive layer of a laminate (phase difference layer/transparent conductive layer) obtained in Example 1 using a bar coater (manufactured by First Science, Inc., trade name "Bar coater No. 06") The composition for forming a hard coat layer was applied thereon, and dried in a blow dryer at 80 ° C for 2 minutes to obtain a laminate (phase difference layer / transparent conductive layer / hard coat layer) having a hard coat layer having a thickness of 5 μm.

The total light transmittance of the obtained laminate was 85.5%. As shown in (4) above, when the polarizing lens is viewed through a polarizing lens, when the absorption axis of the polarizing element of the polarizing plate on the backlight device is orthogonal to the absorption axis of the polarizing lens, the transmitted light can be normally visually recognized. Uncolored transmitted light.

[Example 5]

An adhesive layer having a thickness of 23 μm was formed on the retardation layer of the laminate (phase difference layer/transparent conductive layer/hard coat layer) obtained in Example 4 to obtain a laminate (adhesive layer/phase difference layer/transparent) Conductive layer / hard coat).

As the adhesive for forming the adhesive layer, butyl acrylate-acrylic acid-vinyl acetate copolymer (butyl acrylate: acrylic acid: vinyl acetate (weight ratio) = 100:2:5) 100 parts by weight, and isocyanate are also used. It is a mixture of 1 part by weight of a crosslinking agent. A transparent adhesive layer having a modulus of elasticity of 10 N/cm ² was formed using the adhesive.

The total light transmittance of the obtained laminate was 88.2%. As shown in (4) above, when the polarizing lens is viewed through a polarizing lens, when the absorption axis of the polarizing element of the polarizing plate on the backlight device is orthogonal to the absorption axis of the polarizing lens, the transmitted light can be normally visually recognized. Uncolored transmitted light.

[Comparative Example 1]

Use 1 piece drop The olefinic cycloolefin film (manufactured by Japan ZEON Co., Ltd., trade name "ZEONOR ZF14-100", front phase difference: 1.7 nm, phase difference in thickness direction: 1.8 nm, thickness: 100 μm) was used instead of three PET films (Mitsubishi Resin Co., Ltd.) A laminate was obtained in the same manner as in Example 1 except that the product name was "DIAFOIL T602E25".

The laminate had a surface resistance value of 2.12 × 10 ⁶ Ω/□ and a total light transmittance of 91.6%. As seen from the above (4), when the polarizing lens is viewed through the polarizing lens, when the absorption axis of the polarizing element of the polarizing plate on the backlight device is orthogonal to the absorption axis of the polarizing lens, the transmitted light is not recognized. Further, when the absorption axis of the polarizing element of the polarizing plate on the backlight device and the absorption axis of the polarizing lens are not orthogonal to each other, the transmitted light is colored and recognized.

[Comparative Example 2]

A PET film (manufactured by Mitsubishi Plastics, Inc., trade name "DIAFOIL T602E25") was used as a retardation film to form a retardation layer (frontal phase difference: 1238 nm, phase difference in thickness direction: 3712 nm, thickness: 23 μm), except Further, in the same manner as in Example 1, a laminate in which a transparent conductive layer was formed on the retardation layer was obtained.

The laminate had a surface resistance value of 2.12 × 10 ⁶ Ω/□ and a total light transmittance of 91.9%. When viewing is performed through a polarizing lens as in the above (4), regardless of how the angle between the absorption axis of the polarizing element of the polarizing plate on the backlight device and the absorption axis of the polarizing lens is set, the transmitted light is colored as a rainbow spot and is visually recognized. To.

[Comparative Example 3]

Two PET films (manufactured by Mitsubishi Plastics Co., Ltd., trade name "DIAFOIL T602E25") were used to form a retardation layer (front retardation: 2546 nm, phase difference in thickness direction: 7450 nm, thickness: 69 μm), except Further, in the same manner as in Example 1, a laminate in which a transparent conductive layer was formed on the retardation layer was obtained.

The laminate had a surface resistance value of 2.12 × 10 ⁶ Ω/□ and a total light transmittance of 90.1%. When viewing is performed through a polarizing lens as in the above (4), regardless of how the angle between the absorption axis of the polarizing element of the polarizing plate on the backlight device and the absorption axis of the polarizing lens is set, the transmitted light is colored as a rainbow spot and is visually recognized. To.

10‧‧‧ phase difference layer

20‧‧‧Transparent conductive layer

110‧‧‧Layered body

Claims (6)

A laminated body comprising: a retardation layer; and a transparent conductive layer disposed on one side or both sides of the retardation layer, wherein the retardation layer has a front phase difference of 3500 nm or more at a wavelength of 590 nm, and the transparent conductive layer The surface resistance value is greater than 10 ³ Ω/□ and is 10 ¹² Ω/□ or less. The laminate according to claim 1, wherein the transparent conductive layer comprises a conductive polymer. The laminate according to claim 2, wherein the conductive polymer is selected from the group consisting of a polyacetylene polymer, a polyparaphenylene polymer, a polyaniline polymer, a polythiophene polymer, and a polyparaphenylene copolymer. At least one of the group consisting of a substance and a polypyrrole polymer. The laminate according to any one of claims 1 to 3, further comprising a hard coat layer disposed on a side of the transparent conductive layer opposite to the retardation layer. The laminate according to any one of claims 1 to 3, further comprising an adhesive layer disposed on the outermost side. The laminate according to claim 5, which is provided with the above-mentioned adhesive layer, the retardation layer, the transparent conductive layer, and the hard coat layer in this order.