JP2006035771A - Conductive layer transfer sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive layer transfer sheet capable of transferring a conductive layer having transparency to a molded product. <P>SOLUTION: The conductive layer 2 containing extremely fine conductive fibers 2a and an adhesive layer 3 are formed on a peelable base material 1 in this order and the extremely fine conductive fibers 2a are added to the conductive layer 2 to obtain the conductive layer transfer sheet having transparency and good surface resistivity. The conductive layer 2 is characterized in that the extremely fine conductive fibers 2a are dispersed without being flocculated to come into contact with each other or dispersed in a state separated one by one or in a state that bundles each of which is formed by bundling a plurality of the extremely fine conductive fibers are separated one by one to come into contact with each other and, since the extremely fine conductive fibers are separated to well keep mutual electric continuity, necessary conductivity can be obtained by a small amount of the extremely fine conductive fibers and the conductive layer 2 can be made thin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a conductive layer transfer sheet having a conductive layer containing ultrafine conductive fibers.

Conventionally, for applications that do not like dust, such as clean room partitions, carrier boxes used in semiconductor and liquid crystal manufacturing, outer panels of manufacturing equipment, and viewing windows of manufacturing equipment, anti-static properties that release static electricity and prevent dust adhesion The resin plate is used, and the present applicant also forms an antistatic property made of a transparent thermoplastic resin containing ultrafine long carbon fibers that are twisted and intertwined on the surface of the transparent thermoplastic resin substrate. A transparent resin plate was proposed (Patent Document 1).
On the other hand, a method of thermally transferring a conductive layer is also known. A thermal transfer film (Patent Document 2) in which a heat-meltable ink layer containing a conductive powder such as nickel or carbon black and a mat layer are provided on a base film. There is a conductive layer transfer sheet (Patent Document 3) having a pressure-sensitive adhesive layer whose adhesiveness is reduced by heating and a transfer film including a conductive layer.
Japanese Patent No. 3398587 Japanese Patent No. 2598895 Japanese Patent No. 3015788

However, the antistatic transparent resin plate of the above-mentioned Patent Document 1 has a coating containing long carbon fibers directly applied to the surface of the transparent resin plate, so that the productivity is poor and it is difficult to obtain a long resin plate. Further, the long carbon fibers are dispersed in a flocculated state, and it has been necessary to contain a considerably large amount in order to obtain the required surface resistivity.
Moreover, since the conductive layer of the thermal transfer sheet of Patent Document 2 contains conductive powder, the contact between these conductive powders is poor, and it is necessary to contain a lot of conductive powder. However, it was difficult to obtain transparency.
Furthermore, in the conductive layer transfer sheet of Patent Document 3, the conductive layer is formed by forming a metal such as nickel or gold by a vacuum evaporation method or an electroless plating method. It was not good, and it was inferior in flexibility.

  The present invention has been made to cope with the above-described problems, and provides a conductive layer transfer sheet that can transfer a transparent conductive layer to a molded body by including ultrafine conductive fibers in the conductive layer. This is a solution issue.

  In order to achieve the above object, the conductive layer transfer sheet of the present invention is characterized in that a conductive layer containing ultrafine conductive fibers and an adhesive layer are formed in this order on a peelable substrate.

  In the present invention, the ultrafine conductive fibers contained in the conductive layer are dispersed without contacting each other and are in contact with each other, or are separated one by one or separated in bundles. In this state, it is preferable to disperse and contact each other, and the ultrafine conductive fibers are preferably carbon nanotubes. Moreover, it is preferable that the conductive layer has transparency with a light transmittance of 550 nm wavelength of 50% or more. And it is also preferable that the contact bonding layer is formed with acrylic adhesive resin or polyurethane adhesive resin.

In the present invention, “without agglomeration” is a term that means that the conductive layer is observed with an optical microscope and there is no aggregate having an average diameter of 0.5 μm or more. The term “contact” is a term that means both the case where the ultrafine conductive fibers are actually in contact with each other and the case where the ultrafine conductive fibers are close to each other with a small gap that allows conduction. Further, “conductivity” is measured by JIS K 7194 (ASTM D 991) (resistance is 10 ⁶ Ω or less) or JIS K 6911 (ASTM D 257) (resistance is 10 ⁶ Ω or more), and the surface resistivity is 10 It means a range of ⁰ to 10 ¹¹ Ω / □.

Since the conductive layer transfer sheet of the present invention contains ultra-fine conductive fibers in the conductive layer, the ultra-fine conductive fibers are in contact with each other and conducted, and even if the amount of fibers is reduced, the conductivity is ensured and the surface The resistivity can be easily controlled in the range of 10 ⁰ to 10 ¹¹ Ω / □, and a highly transparent conductive layer can be obtained. Therefore, necessary conductivity can be ensured even if the amount of ultrafine conductive fibers is reduced, transparency can be improved by the amount of decrease in the amount of ultrafine conductive fibers, and the thickness of the conductive layer can be reduced. In particular, if the ultrafine conductive fibers are carbon nanotubes, the carbon nanotubes are thin and long, so that the mutual contact can be ensured better, and a conductive layer transfer sheet having both excellent conductivity and transparency can be obtained. Can do. And if the conductive layer transfer sheet of this invention is used, it can be set as an electroconductive molded object or an antistatic molded object only by transcribe | transferring to a molded object.

  When the light transmittance at a wavelength of 550 nm of the conductive layer is 50% or more, a conductive layer transfer sheet excellent in transparency can be obtained. By transferring the transparent layer to the transparent molded body, the transparent conductive molded body or It can be easily formed into a transparent antistatic molded body, and can be used for a front body of a display device in which transparency is particularly required.

In addition, if the fine conductive fibers contained in the conductive layer are dispersed without being agglomerated and are in contact with each other, the fine conductive fibers are undissolved and sufficient mutual conduction can be ensured as much as the fibers are not agglomerated. A conductive layer transfer sheet having good conductivity can be obtained. In addition, when the ultrafine conductive fibers of the conductive layer are separated one by one, or when a bundle of multiple bundles is separated and bundled one by one and dispersed and in contact with each other, the dispersed one Alternatively, the chances of contact between a bundle of ultrafine conductive fibers increases, and sufficient conduction can be secured, and a conductive layer transfer sheet having good conductivity can be obtained.
Furthermore, if the adhesive layer is formed of an acrylic adhesive resin or a polyurethane adhesive resin, the adhesive layer also has good transparency. Therefore, the transparency of the molded product to which the adhesive layer has been transferred can be improved.

  Hereinafter, representative embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

  FIG. 1 is a cross-sectional view showing an embodiment of the conductive layer transfer sheet of the present invention, FIG. 2A is a schematic cross-sectional view showing a dispersion state of ultrafine conductive fibers inside the conductive layer, and FIG. FIG. 3 is a schematic cross-sectional view showing another dispersion state of the ultrafine conductive fiber in FIG. 3, and FIG. 3 is a schematic plan view showing the dispersion state of the ultrafine conductive fiber when the conductive layer is seen from the plane.

  This conductive layer transfer sheet is obtained by laminating a transparent conductive layer 2 containing ultrafine conductive fibers on one surface (upper surface) of a thin substrate 1 and further laminating an adhesive layer 3 on the upper surface of the conductive layer 2. .

The substrate 1 is required to have releasability and strength at the time of transfer, and is not limited as long as it is a film having this releasability and strength, but polyester, polypropylene, polyethylene, polycarbonate, polyamide Resins such as polyimide, polyvinyl chloride, and acrylic, or metal foils are appropriately used. Among these, in particular, biaxially stretched polyethylene terephthalate is most preferably used.
And in order to improve peelability, the surface treatment etc. can be performed to the surface of the base material 1 with release agents, such as a fluorine type, a silicon type, an alkyd type. The substrate 1 has a thickness of 30 to 500 μm and can be wound around a paper tube or the like.

  The conductive layer 2 formed on one surface of the substrate 1 is a transparent layer containing the ultrafine conductive fibers 2a dispersed therein. The ultrafine conductive fibers 2a are dispersed without contacting each other and are in contact with each other, or the ultrafine conductive fibers 2a are separated one by one without being entangled, or a plurality of bundles are bundled together. In a state where the bundles are separated, they are dispersed and in contact with each other, or these dispersed states are in contact with each other. When the conductive layer 2 is mainly formed of ultrafine conductive fibers 2a and a transparent resin binder 2b, the ultrafine conductive fibers 2a are dispersed within the resin binder 2b as shown in FIG. 2 are dispersed in contact with each other, or as shown in FIG. 2B, a part of the ultrafine conductive fiber 2a enters the inside of the resin binder 2b, and the other part protrudes from the surface of the resin binder 2b. Or exposed to the inside of the adhesive layer 3 and dispersed in the dispersed state and in contact with each other, or a part of the ultrafine conductive fiber 2a is placed inside the resin binder 2b as shown in FIG. The other ultrafine conductive fibers 2a are dispersed and are in contact with each other in a state in which a part protrudes or is exposed from the surface and enters the adhesive layer 3 as shown in FIG.

  The dispersion state seen from the plane of these ultrafine conductive fibers 2a is schematically shown in FIG. As can be seen from FIG. 3, the ultra-fine conductive fibers 2a are slightly bent but separated one by one or one bundle, and do not intricately entangle each other, that is, do not agglomerate. It is dispersed inside or on the surface of the layer 2 and is in contact at each intersection. When dispersed in this way, the fibers are present in a wider range than when they are agglomerated, so the chance of contact between these fibers increases significantly, resulting in conduction and conductivity. Can be significantly increased.

When the ultrafine conductive fibers 2a are dispersed without being unwound, the chances of mutual contact are reduced, and in order to obtain a conductivity of 10 ⁰ to 10 ¹¹ Ω / □, it is necessary to contain a large amount. As a result, the conductive layer 2 Transparency is worse. However, the same contact opportunity can be obtained even if the amount of the ultrafine conductive fiber 2a is reduced by making the ultrafine conductive fiber 2a in the dispersed state, and the amount of the ultrafine conductive fiber 2a can be reduced accordingly. . As a result, the transparency is improved by the amount of the ultrafine conductive fiber 2a that hinders the transparency, and the conductive layer 2 can be made thinner, thereby further improving the transparency.

  The ultrafine conductive fibers 2a do not have to be separated and dispersed completely one by one or one bundle at a time, and there may be small aggregates intertwined in part. Whether such a single piece or a single bundle is separated and dispersed is determined by observing the conductive layer 2 with an optical microscope, and measuring the major and minor diameters of any agglomerated mass, The case where the average value is 0.5 μm or less is said to be dispersed.

On the other hand, if the conductive layer 2 contains the same amount of ultrafine conductive fibers 2a as when agglomerated and dispersed, by making the dispersion state, many contact opportunities between the fibers can be obtained. It can be remarkably improved and can be 10 ⁵ Ω / □ or less.
Furthermore, even if the ultrafine conductive fiber 2a is included in the conductive layer 2 and the thickness of the conductive layer 2 is reduced to 5 to 500 nm, the conductivity can be improved. Therefore, the thickness of the conductive layer 2 is preferably reduced within the above range, and more preferably 5 to 200 nm.

As the ultrafine conductive fibers 2a used for the conductive layer 2, ultrafine carbon fibers such as carbon nanotubes, carbon nanohorns, carbon nanowires, carbon nanofibers, graphite fibrils, metal nanotubes such as platinum, gold, silver, nickel, and silicon, Ultrafine metal fibers such as nanowires, metal oxide nanotubes such as zinc oxide, and ultrafine metal oxide fibers such as nanowires are 0.3 to 100 nm in diameter and 0.1 to 20 μm in length, preferably length. Conductive ultrafine fibers having a thickness of 0.1 to 10 μm are preferably used. These ultrafine conductive fibers 2a are dispersed one by one or one bundle without agglomeration so that when the surface resistivity of the conductive layer 2 is 10 ⁰ to 10 ¹ Ω / □, A light transmittance of 50% or more is obtained, and when the surface resistivity is 10 ² to 10 ³ Ω / □, a light transmittance of 75% or more is obtained, and the surface resistivity is 10 ^4. When it is -10 ⁶ Ω / □, a light transmittance of 85% or more is obtained, and when the surface resistivity is 10 ⁷ to 10 ¹¹ Ω / □, a light transmittance of 93% or more is obtained. . In addition, the said light transmittance shows the transmittance | permeability of the light of the wavelength of 550 nm by a spectrophotometer.

Among these ultrafine conductive fibers 2a, the carbon nanotubes are extremely thin with a diameter of 0.3 to 80 nm. Therefore, when the carbon nanotubes are dispersed one by one or one bundle, the carbon nanotubes are less likely to inhibit light transmission. It is particularly preferable for obtaining a transparent conductive layer 2 having a light transmittance of 50% or more. These ultrafine conductive fibers 2a are dispersed one by one or one bundle without agglomeration inside or on the surface of the conductive layer 2 and contact with each other to ensure conductivity. Therefore, the surface resistivity is within the range of 10 ⁰ to 10 ¹¹ Ω / □ by including the ultrafine conductive fiber 2a in the conductive layer 2 in an amount corresponding to the basis weight of 1.0 to 450 mg / m ^2. It can be controlled freely.

  The weight per unit area is determined by observing the conductive layer 2 with an electron microscope, measuring the area ratio of the ultrafine conductive fiber in the plane area, and measuring the thickness of the conductive layer 2 and the specific gravity of the ultrafine conductive fiber (the ultrafine conductive fiber is carbon In the case of a nanotube, it is a value calculated by multiplying by an average value 2.2 of the literature values 2.1 to 2.3 of the graph.

  The carbon nanotube includes a multi-walled carbon nanotube concentrically provided with a plurality of cylindrically closed carbon walls having different diameters around the central axis, and a single cylindrically closed carbon wall around the central axis. Single-walled carbon nanotubes.

  The former multi-walled carbon nanotube is composed of a plurality of cylindrically closed carbon walls with different diameters as described above, and the tube is made of multi-layers around the central axis, and the carbon wall has a carbon hexagonal network structure. It is formed by. In other cases, the carbon walls are spirally formed in multiple layers. Preferred multi-walled carbon nanotubes are those in which 2 to 30 layers of carbon walls are overlapped. When such multi-walled carbon nanotubes are dispersed in the dispersed state as described above, the light transmittance can be improved. More preferably, carbon walls having 2 to 15 layers are used. Most of the multi-walled carbon nanotubes are dispersed in a state of being separated one by one, but the two- to three-walled carbon nanotubes may be dispersed in a bundle.

On the other hand, the latter single-walled carbon nanotube is composed of a single carbon wall closed in a cylindrical shape around the central axis as described above, and the carbon wall is formed of a carbon hexagonal network structure. Such single-walled carbon nanotubes are difficult to disperse in a state where they are separated one by one, and two or more are gathered into a bundle, which separates one bundle at a time, and the bundles do not agglomerate without complicated entanglement, It is dispersed in the interior or surface of the conductive layer in a simply intersected state, and is in contact at each intersection. Preferably, a bundle of 10 to 50 single-walled carbon nanotubes is used.
This does not exclude the state where single-walled carbon nanotubes are dispersed one by one.

As described above, the conductive layer 2 in which the fine conductive fibers 2a are dispersed without contacting each other without being entangled with each other, and the basis weight of the fine conductive fibers 2a is 1 to 450 mg / m ² , the conductive layer 2 Even if the thickness of the fiber is reduced to 5 to 500 nm, the ultrafine conductive fiber 2a is unraveled so that sufficient mutual conduction is ensured, and the surface resistivity is in the range of 10 ⁰ to 10 ¹¹ Ω / □ and good conductivity is obtained. It becomes possible to express sex. And since the ultrafine conductive fiber 2a is unwound and there is no agglomerate, the light transmission is not hindered and the transparency is good, and the conductive layer 2 is thinned so that the basis weight of the ultrafine conductive fiber 2a is reduced. Will be improved.

Even if the basis weight of the ultrafine conductive fiber 2a is reduced to 1 to 30 mg / m ² , a surface resistivity of 10 ⁴ to 10 ¹¹ Ω / □ can be obtained, and high transparency (light transmittance is 85). % Or more of the conductive layer 2.
Further, when the basis weight of the ultrafine conductive fiber 2a is increased to about 30 to 250 mg / m ² , a surface resistivity of 10 ² to 10 ³ Ω / □ can be obtained, and transparent (light transmittance is 75% or more). The conductive layer 2 can be obtained.
Further, when the basis weight of the ultrafine conductive fiber 2a is increased to about 250 to 450 mg / m ² , the conductive performance of 10 ⁰ to 10 ¹ Ω / □ can be improved, and the transparency of the conductive layer 2 (light ray) (The transmittance is 50% or more).
The light transmittance of the conductive layer 2 is measured using a spectrophotometer, and the light transmittance at 550 nm of the base material in which only the conductive layer 2 is formed and the adhesive layer 3 is not formed is transmitted through the base material 1. It can be obtained by correcting with the light transmittance.
The total light transmittance and haze are values measured according to ASTM D1003.

In order to include a large amount of ultrafine conductive fibers 2a in the conductive layer 2 and to develop better conductivity and transparency, the dispersibility of the ultrafine conductive fibers 2a is increased, and the viscosity of the prepared coating liquid is decreased. It is important to improve workability and form the thin conductive layer 2, and for that purpose, it is important to improve dispersibility by using a dispersant together. As such a dispersant, a polymer dispersant such as an alkyl ammonium salt solution of an acidic polymer, a tertiary amine-modified acrylic copolymer or a polyoxyethylene-polyoxypropylene copolymer, a coupling agent, etc. are preferably used. Is done.
In addition, an additive such as an ultraviolet absorber, a surface modifier, and a stabilizer may be appropriately added to the conductive layer 2 to improve weather resistance and other physical properties.

  The resin binder 2b used for the conductive layer 2 is a transparent thermoplastic resin, particularly polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polymethyl methacrylate, nitrocellulose, chlorinated polyethylene, chlorinated polypropylene, vinylidene fluoride. However, transparent resins such as silicone resins such as melamine acrylate, urethane acrylate, epoxy resin, polyimide resin, and acrylic modified silicate are used. The conductive layer 2 composed of the transparent resin binder 2b and the ultrafine conductive fiber 2a is a transparent layer. In addition, an inorganic material such as colloidal silica may be added to these resin binders.

As mentioned above, the basis weight of the ultra fine conductive fibers 2a in the conductive layer 2 and 1~450mg / ^{m 2,} the thickness of the conductive layer 2 as thin as 5 to 500 nm, 1 present without aggregation of the ultra fine conductive fibers 2a By dispersing one or one bundle at a time, good conductivity and transparency with a surface resistivity of 10 ⁰ to 10 ¹¹ Ω / □ are exhibited. More preferably, the basis weight of the ultrafine conductive fiber 2a is 1 to 200 mg / m ² , and the thickness of the conductive layer 2 is 5 to 200 nm. In addition to the ultrafine conductive fiber, a conductive metal oxide powder may be contained in an amount of about 30 to 50% by mass.

  The adhesive layer 3 provided on the upper side of the conductive layer 2 is an adhesive layer made of either a heat-sensitive adhesive layer or a pressure-sensitive adhesive layer. If it is a heat-sensitive adhesive layer, it can be transferred to the molded body by applying heat during transfer, and if it is a pressure-sensitive adhesive layer, it can be transferred by applying pressure.

As the adhesive resin used for the adhesive layer 3, known acrylic resins, polyurethane resins, vinyl acetate resins, polyolefin resins, polyester resins, vinyl chloride resins and the like can be used, but acrylic resins having particularly excellent transparency, A polyurethane-based adhesive resin is preferably used.
More specifically, examples of the heat-sensitive adhesive include ethylene- (meth) acrylic acid ester-maleic anhydride copolymer, ethylene-vinyl acetate copolymer, partially saponified product of ethylene-vinyl acetate copolymer, It can be appropriately selected from adhesive resins such as ethylene-acrylic acid ester copolymer and low melting point copolymer nylon. The pressure-sensitive adhesive can be appropriately selected from, for example, acrylic emulsion, natural rubber latex, synthetic rubber latex, silicone-based, radiation-curable acrylic pressure-sensitive adhesive, and the like.
The adhesive layer 3 is laminated on the upper surface of the conductive layer 2 by a method such as coating so that the thickness becomes 0.1 to 200 μm. A more preferable thickness is 0.1 to 50 μm, and a most preferable thickness is 1 to 10 μm.

  The conductive layer transfer sheet as described above can be mass-produced efficiently by the following method. For example, a conductive coating liquid is prepared by uniformly dispersing ultrafine conductive fibers 2a in a solution obtained by dissolving the resin binder 2b for forming a conductive layer in a volatile solvent, and the conductive coating liquid has a peelability such as polyethylene terephthalate. By applying and solidifying the upper surface of the substrate 1 to form the conductive layer 2, and further applying and solidifying the adhesive coating liquid made of the adhesive resin to the upper surface of the conductive layer 2 to form the adhesive layer 3, A conductive layer transfer sheet in which the material 1, the conductive layer 2, and the adhesive layer 3 are laminated in this order can be manufactured. A protective film treated with silicon or the like can be further provided on the upper surface of the adhesive layer 3, and in particular, when the pressure-sensitive adhesive layer 3 is used, the protective film is preferably provided.

  The conductive layer transfer sheet thus obtained is obtained by, for example, superimposing the transfer film on one or both sides of an extruded synthetic resin plate and applying heat or / and pressure with a roll to form an adhesive layer 2. And the conductive layer 1 are transferred to a resin plate to form a conductive resin plate. In order to make a conductive resin plate by superimposing a conductive layer transfer sheet on a synthetic resin plate and then applying heat or pressure to transfer the adhesive layer 2 and the conductive layer 1 to the resin plate. used.

  Next, more specific examples of the present invention will be given.

[Example 1]
Single-walled carbon nanotubes (synthesized based on the literature Chemical Physics Letters, 323 (2000) P580-585, diameter 1.3-1.8 nm) in isopropyl alcohol / water mixture (mixing ratio 3: 1) as solvent A polyoxyethylene-polyoxypropylene copolymer as a dispersant was added and mixed and dispersed uniformly to prepare a coating solution containing 0.003% by mass of single-walled carbon nanotubes and 0.05% by mass of a dispersant.

This coating solution was applied to the surface of one side of a commercially available polyethylene terephthalate (PET) film having a thickness of 50 μm (total light transmittance of 90.9%, haze of 0.5%), dried, and further, methyl isobutyl ketone. A conductive layer was formed by applying and drying a thermosetting urethane acrylate solution diluted to 1/600.
The light transmittance at a wavelength of 550 nm of this conductive layer-formed PET film and the original PET film was measured using a Shimadzu Shimadzu spectrophotometer UV-3100PC manufactured by Shimadzu Corporation, and the difference between the light transmittances was 550 nm wavelength of the conductive layer. It was set as the transmittance. As a result, the light transmittance of the conductive layer having a wavelength of 550 nm was 60.5%.

  Further, an acrylic adhesive was applied to the surface of the conductive layer to form an adhesive layer having a thickness of 2.5 μm, and the conductive layer transfer sheet of Example 1 was obtained.

When the surface resistivity on the adhesive layer side of this conductive layer transfer film was measured with Loresta EP manufactured by Mitsubishi Chemical Corporation, the surface resistivity was 8.7 × 10 ¹ Ω / □.
Further, when the total light transmittance and haze of this conductive layer transfer sheet were measured with a direct reading haze computer HGM-2DP manufactured by Suga Test Instruments Co., Ltd. according to ASTM D1003, the total light transmittance was 55.2%. The haze was 4.5%.

Furthermore, when the conductive layer of this conductive layer transfer sheet was observed with an optical microscope, there was no aggregate of 0.5 μm or more, and the single-walled carbon nanotubes were sufficiently dispersed. Therefore, when the conductive layer of this sheet was observed with a scanning electron microscope, the single-walled carbon nanotubes were sufficiently dispersed, and no agglomerates existed even in this electron microscope observation. Then, it was found that a large number of carbon nanotubes were uniformly dispersed in a state where they were separated one by one, and simply contacted in a crossed state.
The measured amount of single-walled carbon nanotubes was 265 mg / m ² .

Furthermore, this conductive layer transfer sheet was overlaid so that the adhesive layer was on the surface side of a polycarbonate resin plate having a thickness of 5 mm during extrusion molding, and was pressure-bonded with a polishing roll, and then only the polyethylene terephthalate film was peeled off. And when the surface resistivity of the conductive polycarbonate resin plate was measured, it was found that it had a surface resistivity of 1.32 × 10 ² Ω / □ and the conductive layer of the conductive layer transfer sheet was transferred. It was.
This conductive polycarbonate resin plate had a total light transmittance of 53.5% and a haze of 5.3%.

[Example 2]
To cyclohexanone as a solvent, 1.7% by mass of vinyl chloride resin powder as a thermoplastic resin was added and dissolved. In this solution, a single-walled carbon nanotube (carbon nanotechnology, diameter 0.7-2 nm) and an alkyl ammonium salt solution of an acidic polymer as a dispersing agent are added and mixed and dispersed uniformly. A coating solution containing 0.18% by mass of a dispersant and 0.18% by mass of a dispersant was prepared. This coating solution was applied to the surface of one side of the same commercially available 50 μm thick polyethylene terephthalate (PET) film as used in Example 1 and dried to form a conductive layer.

  When the light transmittance at a wavelength of 550 nm of the conductive layer of this conductive layer-formed PET film was measured in the same manner as in Example 1, it was 95.5%.

  Furthermore, a polyester urethane adhesive was applied to the surface of the conductive layer to form an adhesive layer having a thickness of 1.5 μm, and the conductive layer transfer sheet of Example 2 was obtained.

When the surface resistivity of this conductive layer transfer sheet was measured with a Hiresta UP manufactured by Mitsubishi Chemical Corporation, the surface resistivity was 6.3 × 10 ⁸ Ω / □.
The conductive layer transfer sheet had a total light transmittance of 87.2% and a haze of 0.7%.
Further, no aggregate of 0.5 μm or more was present in the conductive layer of this conductive layer transfer sheet, and the basis weight of the single-walled carbon nanotubes of the conductive layer was 17 mg / m ² .

Furthermore, this conductive layer transfer sheet was overlaid so that the adhesive layer was on the surface side of a polycarbonate resin plate having a thickness of 5 mm during extrusion molding, and was pressure-bonded with a polishing roll, and then only the polyethylene terephthalate film was peeled off. And when the surface resistivity of the conductive polycarbonate resin plate was measured, it was found that it had a surface resistivity of 2.2 × 10 ⁷ Ω / □ and the conductive layer of the transfer sheet was transferred. This conductive polycarbonate resin plate had a total light transmittance of 83.1% and a haze of 1.2%.

Also, this conductive layer transfer sheet was overlaid so that the adhesive layer was on the surface side of an amorphous polyester resin plate having a thickness of 5 mm during extrusion molding, and after pressure bonding with a polishing roll, only the polyethylene terephthalate film was It peeled. And when the surface resistivity of the conductive amorphous polyester resin plate was measured, it had a surface resistivity of 1.6 × 10 ⁷ Ω / □, and the conductive layer of the conductive layer transfer sheet was transferred. I understood it. This conductive amorphous polyester resin plate had a total light transmittance of 79.3% and a haze of 1.8%.

  In Example 2, the reason why the surface resistivity after transfer was smaller than the surface resistivity before transfer was that carbon that was not dispersed and contacted within the binder of the conductive layer due to the pressure at the time of transfer. Because the nanotubes are compressed and contact each other, or because the conduction is reduced to a space where conduction is possible, the surface resistivity is reduced, or the surface resistivity is reduced because the carbon nanotubes protrude and conduct on the surface of the conductive layer. It is thought that.

It is sectional drawing which shows one Embodiment of the conductive layer transfer sheet which concerns on this invention. (A) is a schematic sectional drawing which shows the dispersion | distribution state of the ultrafine conductive fiber inside the conductive layer of a conductive layer transfer sheet, (B) shows the dispersion | distribution state of the ultrafine conductive fiber on the conductive layer surface of a conductive layer transfer sheet. It is a schematic sectional drawing. It is a schematic plan view which shows the dispersion state of the ultrafine conductive fiber which looked at the conductive layer of the conductive layer transfer sheet from the plane.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Conductive layer 2a Extra fine conductive fiber 3 Adhesive layer

Claims (6)

  A conductive layer transfer sheet, wherein a conductive layer containing ultrafine conductive fibers and an adhesive layer are formed in this order on a peelable substrate.   The conductive layer transfer sheet according to claim 1, wherein the ultrafine conductive fibers contained in the conductive layer are dispersed without being aggregated and are in contact with each other.   The ultrafine conductive fibers contained in the conductive layer are dispersed in contact with each other in a state of being separated one by one or in a state where a plurality of bundles are bundled and separated one by one The conductive layer transfer sheet according to claim 1.   The conductive layer transfer sheet according to any one of claims 1 to 3, wherein the ultrafine conductive fiber is a carbon nanotube.   The conductive layer transfer sheet according to any one of claims 1 to 4, wherein the conductive layer has transparency with a light transmittance at a wavelength of 550 nm of 50% or more.     The conductive layer transfer sheet according to any one of claims 1 to 5, wherein the adhesive layer is formed of an acrylic adhesive resin or a polyurethane adhesive resin.

Images