WO2009125754A1

WO2009125754A1 - Device

Info

Publication number: WO2009125754A1
Application number: PCT/JP2009/057092
Authority: WO
Inventors: 北野　高広
Original assignee: 株式会社クラレ
Priority date: 2008-04-08
Filing date: 2009-04-07
Publication date: 2009-10-15

Abstract

Provided is a device of high durability. In a device having a conductive layer, the conductive layer comprises intertwined single-layer carbon nanotubes and fullerenes, but does not comprise binding resin.

Description

device

The present invention relates to a device having a conductive layer composed of entangled single-walled carbon nanotubes and fullerene (but not using a binder resin). This device is, for example, a liquid crystal display device or a solar battery.

As the market expands, liquid crystal display devices are required to be thinner. In order to reduce the thickness, a liquid crystal display device using a resin film substrate instead of a glass substrate has been proposed. In order to operate this liquid crystal display device, a conductive layer for applying voltage to liquid crystal molecules is necessary. As a material for this conductive layer, a ceramic material typified by indium tin oxide (ITO) has been used.

However, ceramic materials such as ITO have poor flexibility. Therefore, when a resin film is used as the substrate material, it is difficult for the conductive layer using ITO to follow the flexibility of the substrate. For this reason, there is a high possibility that the conductive layer is damaged. A case where the liquid crystal display device does not operate easily occurs.

Further, solar cells using carbon nanotubes as electrode films have attracted attention.
For example, a dye-sensitized solar characterized in that a nanocarbon film made of fibrous carbon having a diameter of nanometer size selected from the group of single wall carbon nanotubes, multiwall carbon nanotubes, and carbon nanofibers is used as an electrode. A battery has been proposed (Japanese Patent Application Laid-Open No. 2004-111216).

Further, a dye-sensitized solar cell electrode substrate having a transparent substrate and a transparent electrode formed on one side of the transparent substrate, the transparent electrode being formed on the transparent substrate, For example, a transparent first conductive layer made of a metal oxide such as ITO or ZnO, a second conductive layer made of a metal such as Pt, Au, or Ni formed on the first conductive layer, and the second For a dye-sensitized solar cell, comprising a third conductive layer formed on a conductive layer, for example, one or two or more carbons selected from the group consisting of fullerenes, fullerene derivatives and carbon nanotubes An electrode substrate, a photoelectrode substrate having a porous semiconductor electrode made of semiconductor fine particles having a dye supported on the surface, a counter electrode substrate disposed opposite to the photoelectrode substrate, the photoelectrode substrate, and the counter electrode substrate, Electrolysis intervening between Proposed is a dye-sensitized solar cell comprising a layer, wherein the photoelectrode substrate is the electrode substrate for a dye-sensitized solar cell (Japanese Patent Laid-Open No. 2005). -142088).

In a solar cell in which a p-type semiconductor material and an n-type semiconductor material are pn-junction or pin-junction, the p-type semiconductor material or the n-type semiconductor material is in a state where a plurality of carbon nanotubes are electrically connected to each other. There has been proposed a solar cell characterized in that it is made of a structure film arranged in the form of JP-A-2006-237204.
JP2004-202948 JP 2005-255985 JP2004-1111216 JP 2005-142088 A JP 2006-237204 A

Now, all of the above proposed techniques still have problems in terms of durability.

Therefore, the first problem to be solved by the present invention is to provide a device with high durability.

The second problem to be solved by the present invention is to provide a high-quality liquid crystal display device that is flexible, hardly damaged, durable, and hardly causes malfunction.

A third problem to be solved by the present invention is to provide a low-cost and highly durable solar cell device.

The above issues are
A device having a conductive layer comprising:
The conductive layer is
Having entangled single-walled carbon nanotubes and fullerenes,
This is solved by a device characterized by having no binder resin.

The single-walled carbon nanotubes contained in the conductive layer of the device are preferably single-walled carbon nanotubes obtained by an arc discharge method.

The single-walled carbon nanotubes contained in the conductive layer of the device are preferably acid-treated single-walled carbon nanotubes.

The fullerene contained in the conductive layer of the device is particularly preferably a fullerene hydroxide.

The amount of fullerene contained in the conductive layer of the device is preferably 10 to 1000 parts by mass with respect to 100 parts by mass of the single-walled carbon nanotube.

It is preferable that a protective layer is provided on the conductive layer of the device.

The conductive layer of the device is preferably provided on a resin substrate.

The second problem is
A device for a liquid crystal display in which a liquid crystal layer is provided between a conductive layer and a conductive layer,
This is solved by a device characterized in that at least one of the conductive layers is a conductive layer of the device.

The third problem is
A solar cell device comprising an electrode substrate having a conductive layer,
Solved by a device characterized in that the conductive layer is a conductive layer of the device.

The solar cell is preferably a solar cell using a redox reaction of a dye.

In the present invention, entangled single-walled carbon nanotubes and fullerenes were used (however, no binder resin was used) to form a conductive layer. For this reason, the device of this invention is excellent in electroconductivity. In addition, it has excellent durability.

And the conductive layer is rich in flexibility. For this reason, in the case of a device (for example, a liquid crystal display device) in which flexibility is required for the conductive layer, the conductive layer can be bent following a substrate made of a resin film, for example. Therefore, this device is not easily damaged and is highly durable. Even in the case of a device that requires operability, it is difficult for malfunction to occur. In addition, the operability is excellent.

In addition, when the conductive layer of the present invention is applied to a solar cell, this layer has excellent conductivity and durability. And since a conductive layer can be comprised simply, a high quality and highly durable solar cell can be obtained at low cost.

The above-mentioned patent document 1 discloses that “a substrate layer made of a transparent resin and a conductive layer laminated on the substrate layer are provided so that the conductive layer is disposed to face the substrate side conductive layer and the substrate side conductive A sheet-like resin laminate for a touch panel, which is in an energized state in contact with a layer, wherein the conductive layer is made of a resin composition in which carbon nanowires are dispersed in a transparent matrix resin Sheet-like resin laminate "A state in which a sheet-like resin laminate for a touch panel comprising a base material layer made of a transparent resin and a conductive layer laminated on the base material layer faces the conductive layer on the substrate-side conductive layer A resin composition in which carbon nanowires are dispersed in a matrix resin in which a conductive layer of the sheet-like resin laminate for a touch panel is transparent and disposed at predetermined intervals on a substrate via spacers Touch panel ", characterized in that it consists is disclosed. Patent Document 2 states that “in the carbon nanotube-containing coating film applied on the substrate, the carbon nanotube-containing coating film has a three-dimensional network structure, and the carbon nanotube-containing coating film is a carbon nanotube-containing coating film”. A carbon nanotube-containing coating film characterized by being exposed on the surface is disclosed.

However,

Patent Documents

1 and 2 do not disclose any liquid crystal cells. In addition, a description reminiscent of a liquid crystal cell is not recognized. That is, Patent Document 1 is only used for a touch panel. Patent Document 2 discloses ESD protection, EMI / RFI shielding, low visibility, polymer electronics (for example, transparent conductive layers of OLED displays, EL lamps, plastic chips, etc.) as applications of carbon nanotube-containing coating films. It has only been done.

And in the thing of the cited

references

1 and 2, since the carbon nanotube is disperse | distributed in resin, the electroconductivity of a conductive layer is not good. Therefore, even if the liquid crystal cells of

Patent Documents

1 and 2 are used, their operability is not good. In other words, the present invention has a feature that cannot be achieved with the ones of

Patent Documents

1 and 2.

Moreover, in the said patent document 3, the carbon nanotube is used for the electrode of a solar cell. However, a solar cell with high durability cannot be obtained only by using carbon nanotubes. That is, with the thing of patent document 3, the feature which this invention show | plays cannot fully be show | played.

Patent Document 4 describes the use of one or more carbons selected from the group consisting of fullerenes, fullerene derivatives and carbon nanotubes. However, in this method, the conductive layer of the electrode substrate is made of, for example, a transparent first conductive layer made of a metal oxide such as ITO or ZnO, and formed on the first conductive layer, for example, Pt, Au, Ni. A second conductive layer made of a metal such as a third conductive layer formed on the second conductive layer, for example, one or two or more carbons selected from the group consisting of fullerenes, fullerene derivatives, and carbon nanotubes And a three-layer laminated conductive layer. For this reason, the flexibility of the conductive layer is lacking. For example, when a resin film or a resin sheet is used as the substrate, the above-mentioned hard conductive layer cannot follow such a flexible substrate, and damage is likely to occur. That is, the durability is inferior. Furthermore, as a result of research by the present inventor, it was found that the latter is more durable when only the carbon nanotubes are used in the conductive layer and when the carbon nanotubes and fullerenes are used in combination. It is. Patent Document 4 describes “a third conductive layer made of one or more carbons selected from the group consisting of fullerenes, fullerene derivatives and carbon nanotubes”, and details of the invention of the specification In the description column, for example, paragraph number [0044] describes that “fullerene, fullerene derivative or carbon nanotube is preferably used”, and “combination of carbon nanotube and fullerene” is not described at all. . Furthermore, even in the examples in which the best mode of the invention is described, there is no description about “combination of carbon nanotube and fullerene”. Moreover, in the thing of patent document 4, binder resin is used for the structure of a conductive layer, As a result, electroconductivity falls. Furthermore, since the conductive layer has a three-layer structure, the cost is high.

In Patent Document 5, carbon nanotubes are used for solar cells, but carbon nanotubes are not used for the conductive layer of the electrode substrate.

Schematic side view of electrode substrate Configuration diagram of liquid crystal cell (top view) Configuration diagram of liquid crystal cell (cross section) Block diagram of liquid crystal cell with polarizing plate (cross section) Measurement results of liquid crystal cell transmittance Titanium oxide multilayer electrode configuration diagram (top view) Solar cell configuration (top view) Solar cell configuration diagram (cross section)

DESCRIPTION OF SYMBOLS 1 Liquid crystal molecule 2

Epoxy resin

3, 4 Electrode substrate 5 Polarizing plate 6

Titanium oxide layer

7, 9 Transparent electrode substrate 8 Epoxy resin 10 Electrolyte solution 11 Substrate 12 Conductive layer 13 Protective layer

The present invention is a device having a conductive layer. This device is a liquid crystal display device or a solar cell device. For example, a liquid crystal display device in which a liquid crystal layer is provided between a conductive layer and a conductive layer. Or it is the device of the solar cell which comprised the electrode substrate which has a conductive layer.

The greatest feature of the present invention is the conductive layer constituting the device. That is, the conductive layer (at least one conductive layer in the case of a device for a liquid crystal display) is configured by using both entangled single-walled carbon nanotubes and fullerenes. That is, the conductive layer has entangled single-walled carbon nanotubes and fullerenes. However, the conductive layer does not have a binder resin. As shown in FIG. 1, the conductive layer 12 is provided on a substrate (for example, a resin substrate) 11. The conductive layer 12 is configured without using a binder resin. In order to make the binder resin unnecessary, single-walled carbon nanotubes constituting the conductive layer 12 have a structure in which the single-walled carbon nanotubes are intertwined with each other. As a result, the single-walled carbon nanotubes are in direct contact with each other. Therefore, since there is no intervening insulator, the conductivity is good. In addition, since the single-walled carbon nanotubes are entangled with each other, the conductive layer 12 does not require a binder resin. If the surface of the conductive layer is observed with a scanning electron microscope, it can be confirmed / determined whether the single-walled carbon nanotubes are intertwined.

The single-walled carbon nanotube may be a single-walled carbon nanotube obtained by any manufacturing method. For example, single-walled carbon nanotubes obtained by production methods such as arc discharge, chemical vapor deposition, and laser evaporation can be used. However, single-walled carbon nanotubes obtained by an arc discharge method are preferred from the viewpoint of crystallinity. And this thing is also easily available.

The single-walled carbon nanotube is preferably a single-walled carbon nanotube subjected to acid treatment. The acid treatment is performed by immersing single-walled carbon nanotubes in an acidic liquid. A technique called spraying may be employed instead of immersion. Various kinds of acidic liquids are used. For example, an inorganic acid or an organic acid is used. However, inorganic acids are preferred. For example, nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, or a mixture thereof can be used. Among these, acid treatment using nitric acid or a mixed acid of nitric acid and sulfuric acid is preferable. Preferable acid treatment conditions are conditions in which the reaction is carried out at a temperature of 80 ° C. to 100 ° C. for 1 day to 7 days. By this acid treatment, when single-walled carbon nanotubes and carbon fine particles are physically bonded via amorphous carbon, the amorphous carbon is decomposed and separated from each other, or the metal used for producing single-walled carbon nanotubes The fine particles of the catalyst will be decomposed. Therefore, in the present invention, acid treatment of single-walled carbon nanotubes is a very important requirement. For example, the conductivity is improved as compared with the case where acid treatment is not performed.

The single-walled carbon nanotube is preferably a single-walled carbon nanotube in which impurities are removed by filtration and purity is improved. This is because a decrease in conductivity and a decrease in light transmittance due to impurities are prevented. Various methods are employed for filtration. For example, suction filtration, pressure filtration, cross flow filtration and the like are used. Among these, from the viewpoint of scale-up, it is preferable to employ cross flow filtration using a hollow fiber membrane.

The conductive layer 12 includes not only entangled single-walled carbon nanotubes but also fullerenes (in the present specification, “fullerene” includes “fullerene analogues”, the same shall apply hereinafter). This is because the heat resistance is improved by including fullerene. Moreover, it is because it was excellent also in electroconductivity.

The fullerene may be any fullerene. For example, C60, C70, C76, C78, C82, C84, C90, C96 etc. are mentioned. Of course, a mixture of plural kinds of fullerenes may be used. C60 is particularly preferable from the viewpoint of dispersion performance. Furthermore, C60 is easy to obtain. Further, not only C60 but also a mixture of C60 and another kind of fullerene (for example, C70) may be used. Moreover, the metal atom may be included in the fullerene. Examples of the fullerene analog include those containing a functional group (for example, a functional group such as OH group, epoxy group, ester group, amide group, sulfonyl group, ether group). Further, those having phenyl-C61-propyl acid alkyl ester and phenyl-C61-butyric acid alkyl ester are also included. In addition, hydrogenated fullerene is also included. Among them, fullerene having an OH group (hydroxyl group) (fullerene hydroxide) is preferable. This is because the dispersibility during coating of the single-walled carbon nanotube dispersion was high. In addition, when there is little quantity of a hydroxyl group, the dispersibility improvement degree of a single-walled carbon nanotube will fall. On the other hand, if too much, synthesis is difficult. Accordingly, the amount of OH groups is preferably 5 to 30 per molecule of fullerene. In particular, 8 to 15 are preferable.

If the addition amount (content) of fullerene is too large, the conductivity decreases. Conversely, if the amount is too small, the effect is poor. Accordingly, the amount of fullerene is preferably 10 to 1000 parts by mass (particularly 20 parts by mass or more and 100 parts by mass or less) with respect to 100 parts by mass of single-walled carbon nanotubes.

It is preferable that a protective layer 13 is provided on the conductive layer 12 in the device of the present invention. There is no particular limitation on the material used for the protective layer 13. For example, a thermoplastic resin such as a polyester resin, a cellulose resin, a polyvinyl alcohol resin, a vinyl resin, a cycloolefin resin, a polycarbonate resin, an acrylic resin, or an ABS resin is used. Moreover, well-known coating materials, such as a photocurable resin and a thermosetting resin, may be used. However, the material of the protective layer 13 is preferably the same (same system) material as the substrate 11 from the viewpoint of adhesion. For example, when the substrate 11 is a polyester resin, the protective layer 13 is also preferably a polyester resin. When the thickness of the protective layer 13 is too thick, the contact resistance of the transparent conductive layer increases. On the contrary, if the thickness of the protective layer 13 is too thin, the effect as the protective layer cannot be obtained. Therefore, the thickness of the protective layer 13 is preferably 1 nm to 1 μm. In particular, 10 nm or more is preferable. Moreover, 100 nm or less is preferable.

Next, a case where the conductive layer is applied to a liquid crystal cell (a liquid crystal cell of a liquid crystal display device) will be described. As is known, a liquid crystal cell is provided with a liquid crystal layer between a conductive layer and a conductive layer. More specifically, in the liquid crystal cell, a layer (liquid crystal layer) made of liquid crystal molecules is provided between the electrode substrate and the electrode substrate. The electrode substrate is obtained by providing a conductive layer on a transparent substrate, for example. In the present invention, at least one of the conductive layers is composed of the conductive layer of the present invention (binder resin is not included. Entangled single-walled carbon nanotubes and fullerenes are included). The In addition, it is preferable that both conductive layers are composed of the conductive layer of the present invention. However, only one of them has an effect. The liquid crystal cell is used to form a liquid crystal display device.

The basic structure of a liquid crystal cell is one in which a conductive layer is provided on at least one substrate. In addition, an alignment film is provided on the substrate. This alignment film is arranged in opposition to the inside. In this structure, liquid crystal molecules are sealed between the alignment films arranged opposite to each other. The conductive layer in such a liquid crystal display element is generally configured in the form of a display pattern such as a stripe shape or a lattice shape on a substrate. The alignment film is provided by coating (or vapor deposition) on the entire surface of the transparent electrode and the exposed substrate (other than the display pattern). Each of the transparent electrode substrates including the two conductive layers is arranged with the alignment film inside. A liquid crystal cell is formed by enclosing a liquid crystal material in the meantime. Accordingly, the encapsulated liquid crystal molecules are generally in contact only with the alignment film. Generally, the alignment film is provided because it is necessary to align (that is, align) the liquid crystals in a certain direction. Thereby, the liquid crystal molecules are aligned.

Various modes such as TN (Twisted T Nematic), VA (Vertical Alignment), IPS (In-Plane Switching), OCB (optically 等 compensated birefringence) are known for the liquid crystal cell.

Various kinds of liquid crystal molecules are used. A rod-like molecular compound is preferably used. For example, preferred are azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano substituted phenylpyrimidines, alkoxy substituted phenylpyrimidines, Phenyldioxanes, tolanes, and alkenylcyclohexylbenzonitriles are used. Examples of the liquid crystal compounds of TN, VA, IPS, and OCB include the liquid crystal compounds described in JP-A-11-302653, JP-A-9-249481, JP-A-2002-193853, and JP-A-2003-73670.

Also, a color filter layer can be provided.

The electrode substrate is preferably a sheet or film. The substrate preferably has a total light transmittance of 80% to 100%. There are no particular restrictions on the material of the substrate. A flexible transparent substrate is preferable. There are no particular restrictions on the material of the transparent substrate. For example, in addition to ceramics such as glass, thermoplastic resins (for example, polyester resin, cellulose resin, polyvinyl alcohol resin, vinyl chloride resin, cycloolefin resin, polycarbonate resin, acrylic resin, ABS resin, etc.) are used. . Alternatively, a photocurable resin or a thermosetting resin is also used. The thickness of the transparent substrate 11 depends on the application. When a sheet shape is required, it is about 500 μm to 10 mm. When a film shape is required, it is about 10 μm to 500 μm. In the liquid crystal cell of the present invention, any of the two substrates may be a sheet or a film. One may be a sheet and the other may be a film.

The device of the present invention may be one in which only the conductive layer provided on one transparent substrate is composed of the single-walled carbon nanotubes of the present invention. That is, the conductive layer provided on the other electrode substrate may be made of, for example, ITO. Of course, it is preferable that both conductive layers are composed of single-walled carbon nanotubes.

The total light transmittance of the electrode substrate at the stage where the conductive layer is laminated on the substrate is preferably 60% to 100%. The surface resistance value is 1Ω / □ to 1000Ω / □. This is because if the total light transmittance is too low, the visibility is lowered. A conductive layer using single-walled carbon nanotubes has a trade-off relationship between the total light transmittance and the surface resistance value. Accordingly, the surface resistance value is preferably low as long as the liquid crystal cell operates. Here, the total light transmittance is the total light transmittance including not only the conductive layer containing single-walled carbon nanotubes but also the base material. More preferably, the total light transmittance is 70% or more, and the surface resistance value is 10Ω / □ to 100Ω / □. In particular, the total light transmittance is 80% or more and the surface resistance is 10Ω / □ to 50Ω / □.

The liquid crystal cell of the present invention can be produced by the following steps.
Step 1: Process for obtaining crude carbon nanotubes Step 2: Acid treatment process for treating crude carbon nanotubes with acid Step 3: Filtration process for filtering single-walled carbon nanotubes obtained in Step 2 Step 4: With single-walled carbon nanotubes Dispersion process step 5 in which the solvent is mixed and ultrasonic irradiation is performed: Single-walled carbon nanotube dispersion obtained in step 4 is applied onto the substrate. Application step 6: On the electrode substrate obtained in step 5 Step 7 in which an alignment film is formed Step: Step in which the electrode substrate obtained in Step 6 is opposed to each other through a spacer and liquid crystal molecules are filled in the gaps. Steps 1 to 7 are performed in this order. Are preferred.

Hereinafter, each process will be described in more detail.
[Step 1]
There are no particular restrictions on the method of obtaining the crude carbon nanotube. Any manufacturing method such as an arc discharge method, a chemical vapor phase method, or a laser evaporation method can be used. From the viewpoint of crystallinity, the arc discharge method is preferably used. And this thing is also easy to obtain.

[Step 2]
Step 2 is a step in which single-walled carbon nanotubes are heated in an acidic liquid. There are no particular restrictions on acidic liquids. For example, nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid and a mixture thereof can be used. Nitric acid or a mixed acid of nitric acid and sulfuric acid is preferably used. The heating temperature is preferably 80 ° C. to 100 ° C. The heating time is preferably 1 to 7 days.

[Step 3]
Step 3 is a step in which the single-walled carbon nanotubes obtained in Step 2 are filtered. Thereby, impurities such as carbon particles are removed. That is, the carbon nanotube solution after acid treatment is dispersed (or precipitated) in the solution in a state where, for example, impurity particles having a diameter of about 20 nm and carbon nanotube bundles are separated. For this reason, the impurities are removed by filtration using a filter having a pore size larger than the impurities and smaller than the bundle of carbon nanotubes. Various methods can be adopted as the filtration method. For example, suction filtration, pressure filtration, cross flow filtration and the like are used. Among these, from the viewpoint of scale-up, cross flow filtration using a hollow fiber membrane is preferable.

[Step 4]
Step 4 is a step in which a single-walled carbon nanotube dispersion is produced. In this step, fullerene is added. There are no particular restrictions on the ratio of single-walled carbon nanotubes to fullerenes. However, the fullerene is preferably 10 to 1000 parts by mass with respect to 100 parts by mass of the single-walled carbon nanotube. The fullerene concentration is preferably 1 to 100,000 ppm. The fullerene is preferably a fullerene having a functional group. In particular, fullerene having an OH group (fullerene hydroxide) is preferable. Various methods can be adopted as the ultrasonic irradiation method. For example, a bus type ultrasonic irradiator or a chip type ultrasonic irradiator is used. From the viewpoint of processing in a shorter time, it is preferable to employ a chip-type ultrasonic irradiator. There is no special restriction | limiting in the solvent used by this invention. However, a solvent having a boiling point of 200 ° C. or lower (preferably lower limit is 25 ° C., further 30 ° C.) is preferable. The low boiling point solvent is preferred because it is easy to dry after coating. Specifically, water, alcohol (for example, alcohol such as methanol, ethanol, normal propanol, and isopropanol (particularly alcohol having 7 or less carbon atoms, particularly aliphatic alcohol)), or a mixture thereof is preferable. This is because the hydroxyl group-containing fullerene has high solubility, and thus a single-walled carbon nanotube dispersion with a higher concentration can be obtained. In addition, ketone compounds (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ester compounds (eg, methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, methoxyethyl acetate, etc.), ether compounds ( For example, diethyl ether, ethylene glycol dimethyl ether, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, dioxane etc.), aromatic compounds (eg toluene, xylene etc.), aliphatic compounds (eg pentane, hexane etc.), halogenated hydrocarbons (eg For example, methylene chloride, chlorobenzene, chloroform, etc.), and mixtures thereof may be used.

[Step 5]
Step 5 is a step in which the single-walled carbon nanotube dispersion obtained in step 4 is applied onto the substrate. That is, it is a step in which a conductive layer is formed on the substrate. Specifically, this is a step in which the dispersion is applied onto a transparent substrate by a desired application method (for example, spray coating, bar coating, roll coating, ink jet method, screen coating, die coating, etc.). If necessary, drying is performed after the coating step in order to remove the solvent contained in the coating film. A drying device (for example, a heating furnace, a far infrared furnace, a super far infrared furnace, or the like) is used for drying. Further, the substrate is cleaned as necessary.

[Step 6]
Step 6 is a step in which an alignment film is formed on the electrode substrate obtained in step 5. In this step, an alignment film necessary for aligning liquid crystal molecules is formed. Usually, in the alignment treatment, a polymer film such as polyimide is provided on a substrate such as glass. A method (rubbing) called friction with a cloth or the like in one direction is used. As a result, the liquid crystal molecules in contact with the substrate are arranged so that their long axes (directors) are parallel to the rubbing direction. A technique such as a photo-alignment method that does not require rubbing may be used. Specifically, light is irradiated to a compound having a group (hereinafter, abbreviated as a photo-alignment group) whose light absorption ability varies depending on the direction of the electric vector of polarized light. Thereby, a photo-alignment group arranges in a fixed direction, and liquid crystal alignment ability expresses. Examples of the photoalignment group include a group causing a photoisomerization reaction such as azobenzene, a group causing a photodimerization reaction such as a cinnamoyl group, a coumarin group, and a chalcone group, a group causing a photocrosslinking reaction such as a benzophenone group, or the like. A polyimide, a silane compound, etc. are known.

[Step 7]
In step 7, usually, first, a sealing material is applied to the peripheral edge of the surface of one of the substrates. At that time, a liquid crystal injection port is formed in a part of the sealing material. Next, a spacer is provided inside the sealing material. And the other board | substrate is bonded together through a sealing material. Thereby, a liquid crystal cell is formed in a region surrounded by the pair of substrates and the sealing material. Next, the inside of the liquid crystal cell is deaerated in a vacuum. And the whole is returned to atmospheric pressure in the state where the liquid crystal inlet was immersed in the liquid crystal tank. As a result, the liquid crystal is filled in the liquid crystal cell by the pressure difference between the liquid crystal cell and the outside and the surface tension. Alternatively, a droplet assembly method in which liquid crystal is applied onto a substrate using a droplet discharge device such as an inkjet may be used. Specifically, first, a sealing material made of a thermosetting resin or the like is applied to the surface peripheral portion of one substrate. Next, a predetermined amount of liquid crystal is dropped inside the sealing material by a droplet discharge device. Finally, the other substrate is bonded through a sealing material, whereby a liquid crystal cell is obtained.

A liquid crystal display device is obtained by combining a liquid crystal cell obtained as described above with a polarizing filter, a retardation film, or the like.

Next, a case where the conductive layer is applied to a solar cell will be described. Examples of solar cells that require a conductive layer include dye-sensitized solar cells, single crystal silicon solar cells, other crystal silicon solar cells, and solar cells using indirect transition semiconductors such as amorphous silicon solar cells. It is done. _{Further, CuInSe 2 (CIS), Cu} (In, Ga) solar cell using a direct transition type semiconductor such as Se ₂ (CIGS) can also be mentioned. However, a dye-sensitized solar cell (a solar cell using a redox reaction of a dye) is particularly preferable.

太陽 There are no particular restrictions on the layer structure of solar cells. For example, in a dye-sensitized solar cell, the layer configuration of transparent substrate / transparent electrode layer / photocatalyst layer / electrolyte layer / transparent electrode layer / substrate is exemplified. In the silicon-based solar cell, a layer configuration of transparent substrate / transparent electrode / p-type semiconductor / n-type semiconductor is given as an example. In the CIS solar cell, the layer configuration of substrate / electrode / light absorption layer / buffer layer / transparent electrode layer / antireflection layer is an example.

As described above, the present invention is suitably used for a dye-sensitized solar cell. Therefore, in the following, the dye-sensitized solar cell will be described in detail.

Two boards are required. At least one of the two substrates has light transmittance. Specifically, the total light transmittance is 80% or more and 100% or less. And preferably, a sheet form or a film form is used.

There are no special restrictions on the board material. For example, ceramic such as glass can be used. In addition, thermoplastic resins such as polyester resin, cellulose resin, vinyl alcohol resin, vinyl chloride resin, cycloolefin resin, polycarbonate resin, acrylic resin, and ABS resin can be used. In addition, a photocurable resin, a thermosetting resin, etc. are mentioned. In addition, from the viewpoint of flexibility, it is preferably made of resin.

The thickness of the substrate depends on the application. In the case of a sheet shape, for example, it is 500 μm to 10 mm. In the case of a film, it is, for example, 10 μm to 500 μm.

An oxide (for example, anatase type titanium oxide, rutile type titanium oxide, zinc oxide, tin oxide, nibismuth trioxide, etc.) is used for the photocatalyst layer. Among these, sol-like anatase-type titanium oxide TiO ₂ is preferable. This is because when a sol-like anatase-type titanium oxide TiO ₂ is used, an extremely smooth surface is formed when the contacting side is hydrophilic.

The film thickness of the photocatalyst layer is preferably 0.01 μm to 10 μm when anatase TiO ₂ is used. This is because when the film thickness is less than 0.01 μm, problems such as coating defects such as pinholes are likely to occur. Conversely, if the film thickness exceeds 10 μm and becomes too thick, the light transmittance decreases.

The photocatalyst layer is formed by forming (or adsorbing) a dye layer made of a ruthenium complex on the surface of titanium oxide TiO ₂ . Such a dye may be any substance that has an improved absorption function in the wavelength range of sunlight. For example, chlorophyll and rhodamine are used.

A redox redox solution is used for the electrolyte layer. Specifically, a couple of anions that rapidly change between a plurality of different oxidation states by light irradiation and electron supply are used as the electrolyte. Examples of the anion couple having such a property include halogen couples such as iodine (I ⁻ / I ³⁻ ), bromine (Br ²⁻ / Br ⁻ ), and chlorine (ClO ⁻ / Cl ⁻ ). The degree of ionization is I>Br> Cl. The electrolytic solution may be impregnated and used in a porous material typified by cloth, paper or the like.

The conductive layer in the solar cell preferably has a total light transmittance of 60% to 100%. Preferably, the surface resistance value is 10Ω / □ to 1000Ω / □ or less. This is because if the total light transmittance is too low, the power generation is reduced. In the conductive layer using single-walled carbon nanotubes, there is a trade-off relationship between the total light transmittance and the surface resistance value. Therefore, the surface resistivity is preferably higher as long as the solar cell operates.

The solar cell of the present invention can be produced by the following steps.
Step 11: Step for obtaining crude carbon nanotube Step 12: Acid treatment step for acid treatment of crude carbon nanotube Step 13: Filtration step for filtering the single-walled carbon nanotube obtained in Step 12 Step 14: Single-walled carbon nanotube and solvent Are dispersed and ultrasonic irradiation is performed. Dispersion process step 15: Single-walled carbon nanotube dispersion obtained in step 14 is applied onto the substrate. Application step 16: On the electrode substrate obtained in step 15. Step for Forming Photoelectric Conversion Layer The above steps 11 to 16 are preferably performed in this order.

Hereinafter, each process will be described in more detail.

[Step 11]
Step 11 is performed in the same manner as step 1.

[Step 12]
Step 12 is performed in the same manner as step 2.

[Step 13]
Step 13 is performed in the same manner as step 3.

[Step 14]
Step 14 is performed in the same manner as step 4.

[Step 15]
Step 15 is performed in the same manner as step 5.

[Step 16]
Step 16 is a step in which a photoelectric conversion layer is formed on the electrode substrate obtained in Step 15. A known method is used for each of the solar cell types, that is, a dye-sensitized solar cell, a silicon-based solar cell, and a CIGS-based solar cell. In addition, when there exists the process heated in the process 16, 1500 degrees C or less is preferable. Moreover, it is preferable that it is under inert gas atmosphere, such as nitrogen, neon, and argon. Further, it is preferably in a low pressure or in a vacuum. This is because there is a high risk that the single-walled carbon nanotube is destroyed.
Hereinafter, more specific description will be given.

[Liquid crystal display device]
[Example 1]
[Production of electrode substrate]
Single-walled carbon nanotubes produced by the arc discharge method were treated with acid (treated with 63% nitric acid at 85 ° C. for 2 days (reaction)). Filtration was then performed. As a result, single-walled carbon nanotubes were purified and recovered.
10 mg of this single-walled carbon nanotube, 10 mg of hydroxyl group-containing fullerene (trade name Nanomuspectra D-100 Frontier Carbon), 1 mg of sodium hydroxide (Wako Pure Chemical Industries), 5 ml of water, 5 ml of 2-propanol, Were mixed. Then, ultrasonic irradiation for 1 minute (device name: ULTRASONIC HOMOGENIZER MODEL UH-600SR, manufactured by SMT Corporation) was performed. As a result, a single-walled carbon nanotube dispersion was obtained.
This single-walled carbon nanotube dispersion was spray-coated on a resin substrate so that the surface resistance was 30Ω / □ (device name: Loresta-FP, manufactured by Dia Instruments). And it dried for 3 minutes at 80 degreeC, and the transparent conductive layer was formed. The total light transmittance was 63% (device name: direct reading haze computer, manufactured by Suga Test Instruments Co., Ltd.). The coated surface was washed with methanol. Thereafter, the transparent conductive layer was immersed in a solution diluted with 2-propanol so that the solid content concentration of the acrylic resin (trade name Watersol S-707-IM) was 1% by mass. Then, a protective layer having a wet thickness of 10 nm was formed, and an electrode substrate was obtained. In addition, it was 31Ω / □ where the surface resistance after being left in an oven at 80 ° C. for 10 days was measured. That is, it can be seen that the resistance value hardly changes, and the durability is excellent.
An electrode substrate obtained by spray-coating the above single-walled carbon nanotube dispersion on a PET film (trade name: Cosmo Shine A4100, manufactured by Toyobo Co., Ltd.) was wound around a rod. The surface resistance was measured by the two-terminal method while being pulled with a constant load. When the radius at which the surface resistance value suddenly increased (limit radius of curvature) was examined, the limit radius of curvature was 2 mm or less. On the other hand, when the critical curvature radius of the PET film with ITO in which the conductive layer was made of ITO was examined, it was 10 mm. This indicates that the conductive layer according to the present invention is rich in flexibility.

[Production of liquid crystal cell]
The electrode substrate was cut into 25 mm squares and arranged such that the conductive layers faced each other. The two electrode substrates were fixed with a room temperature curing type epoxy resin (trade name: Quick5 manufactured by Konishi Co., Ltd.) through a 50 μm spacer. After the epoxy resin was cured, the spacer was removed. Liquid crystal molecules (4-cyano-4′-pentylbiphenyl, manufactured by Tokyo Chemical Industry Co., Ltd.) were injected. After the injection, the injection port was sealed with a room temperature curable epoxy resin. As a result, a liquid crystal cell was produced (see FIGS. 1, 2 and 3).
Thereafter, polarizing plates were bonded to both surfaces of the liquid crystal cell (see FIG. 4). Note that the bonded polarizing plates are orthogonal to each other.
Then, a polarizing plate was bonded, and a voltage (500 Hz, 10 v) was applied to the liquid crystal cell. The transmittance before and after this was measured with a spectrophotometer. The result is shown in FIG.
From FIG. 5, it can be seen that the light transmittance is lower after the voltage application than before the voltage application, and operates as a liquid crystal cell.

[Comparative Example 1]
In Example 1, the same procedure was performed except that the hydroxyl group-containing fullerene was not used when preparing the single-walled carbon nanotube dispersion.
The liquid crystal cell of this comparative example was examined in the same manner as in Example 1.
As a result, it was found to operate as a liquid crystal cell.
However, the liquid crystal cell produced with the electrode after being held at 80 ° C. for 10 days did not operate. This indicates that the liquid crystal cell of this comparative example is inferior in durability and reliability as compared with the liquid crystal cell of the present invention in which the conductive layer has fullerene.

[Comparative Example 2]
In Example 1, the same procedure was performed except that 0.1 mg of polyvinylpyrrolidone was used as the binder resin when the single-walled carbon nanotube dispersion was prepared.
The liquid crystal cell of this comparative example was examined in the same manner as in Example 1.
As a result, it was found to operate as a liquid crystal cell.
However, operation required a voltage of 30V.
This indicates that the liquid crystal cell of this comparative example is inferior to the liquid crystal cell of the present invention in which the conductive layer does not contain a binder resin.

[Solar cell device]
[Example 11]
[Production of electrode substrate]
Single-walled carbon nanotubes produced by the arc discharge method were treated with acid (treated with 63% nitric acid at 85 ° C. for 2 days (reaction)). Filtration was then performed. As a result, single-walled carbon nanotubes were purified and recovered.
10 mg of this single-walled carbon nanotube, 10 mg of hydroxyl group-containing fullerene (trade name Nanomuspectra D-100 Frontier Carbon), 1 mg of sodium hydroxide (Wako Pure Chemical Industries), 5 ml of water, 5 ml of 2-propanol, Were mixed. Then, ultrasonic irradiation for 1 minute (device name: ULTRASONIC HOMOGENIZER MODEL UH-600SR, manufactured by SMT Corporation) was performed. As a result, a single-walled carbon nanotube dispersion was obtained.
This single-walled carbon nanotube dispersion was spray-coated on a resin substrate so that the surface resistance was 30Ω / □ (device name: Loresta-FP, manufactured by Dia Instruments). And it dried for 3 minutes at 80 degreeC, and the transparent conductive layer was formed. The total light transmittance was 63% (device name: direct reading haze computer, manufactured by Suga Test Instruments Co., Ltd.). And the coating surface was wash | cleaned with methanol, and the electrode substrate was obtained. The surface resistance after 10 days in an oven at 80 ° C. was measured. The result was 31Ω / □. That is, it can be seen that the resistance value hardly changes, and the durability is excellent.

[Production of solar cells]
3 g of titanium oxide powder (manufactured by Asahi Sangyo Co., Ltd.), 4 ml of an aqueous nitric acid solution (pH 4), and 13 ml of ethanol were mixed. This mixture was subjected to ultrasonic irradiation for 1 minute. Thereby, a titanium oxide dispersion was obtained. This titanium oxide dispersion was applied on the electrode substrate so as to have a film thickness of 50 μm. And it dried for 5 minutes at room temperature (refer FIG. 6).
Thereafter, firing was performed in an electric furnace (manufactured by ADVANTEC) at 450 ° C. for 30 minutes in a nitrogen atmosphere.
On the other hand, mallow blue (Asahi Sangyo Co., Ltd.) was immersed in distilled water. And the mallow blue aqueous solution was produced. Then, the fired electrode was immersed in a mallow blue aqueous solution. As a result, mallow blue was adsorbed on the titanium oxide layer.
Next, the electrode with a titanium oxide layer and the untreated electrode were stacked so that the electrodes face each other. Then, the two opposite sides were fixed with a room temperature curable epoxy resin (trade name: Quick5 manufactured by Konishi Co., Ltd.).
Thereafter, an iodide electrolyte solution (a mixture of 0.5 M potassium iodide solution and 0.05 M iodine solution) was injected between the electrodes. As a result, a dye-sensitized solar cell was produced (see FIGS. 7 and 8).
The solar cell obtained as described above was irradiated with UV by a UV irradiation device (trade name Toscure 401, manufactured by Harrison Toshiba Lighting). As a result, power with a voltage of 260 mV and a current of 2.1 μA was obtained.

[Comparative Example 11]
In Example 11, the same procedure was performed except that 0.1 mg of polyvinyl pyrrolidone was used as the binder resin when preparing the single-walled carbon nanotube dispersion.
The durability of the electrode substrate of the solar cell thus obtained was examined. As a result, the resistance (30Ω / □) before being left in an 80 ° C. oven for 10 days was 32Ω / □ after being left in an 80 ° C. oven for 10 days. The power characteristics examined in the same manner as in Example 11 were a voltage of 200 mV and a current of 1.8 μA. This shows that the solar cell of this comparative example is inferior to the solar cell of Example 11.

[Comparative Example 12]
In Example 11, the same procedure was performed except that the hydroxyl group-containing fullerene was not used.
The durability of the electrode substrate of the solar cell thus obtained was examined. As a result, the resistance (30Ω / □) before being left in an oven at 80 ° C. for 10 days increased to 300Ω / □ after being left in an oven at 80 ° C. for 10 days, which was inferior in durability. The power characteristics examined in the same manner as in Example 11 were a voltage of 40 mV and a current of 0.3 μA. This shows that the solar cell of this comparative example is inferior to the solar cell of Example 11.

This application claims priority based on Japanese Patent Application No. 2008-100372 and Japanese Patent Application No. 2008-100373 filed on Apr. 8, 2008, the entire disclosure of which is incorporated herein.

Claims

A device having a conductive layer comprising:
The conductive layer is
Having entangled single-walled carbon nanotubes and fullerenes,
A device characterized by having no binder resin.
The device according to claim 1, wherein the single-walled carbon nanotube is a single-walled carbon nanotube obtained by an arc discharge method.
The device according to claim 1, wherein the single-walled carbon nanotube is an acid-treated single-walled carbon nanotube.
The device of claim 1, wherein the fullerene is a fullerene hydroxide.
The device according to claim 1 or 4, wherein the fullerene amount is 10 to 1000 parts by mass with respect to 100 parts by mass of the single-walled carbon nanotube.
The device according to any one of claims 1 to 5, wherein a protective layer is provided on the conductive layer.
The device according to any one of claims 1 to 6, wherein the conductive layer is provided on a resin substrate.
A device for a liquid crystal display in which a liquid crystal layer is provided between a conductive layer and a conductive layer,
8. The device according to claim 1, wherein at least one of the conductive layers is a conductive layer of the device according to any one of claims 1 to 7.
A solar cell device comprising an electrode substrate having a conductive layer,
8. The device according to claim 1, wherein the conductive layer is a conductive layer of the device according to any one of claims 1 to 7.
The device according to claim 9, wherein the solar cell is a solar cell utilizing a redox reaction of a dye.