JP4484347B2 - Transparent conductive film and touch panel - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a transparent conductive film, particularly applied to a touch panel and the like, and is a transparent conductive film provided with a specific anchor layer which is excellent in durability, visibility on a display, and particularly effective in scratch resistance and prevention of sticking. Concerning sex film.
[0002]
[Prior art]
In recent years, transparent touch panels using a transparent conductive film have been frequently used. A transparent touch panel inputs predetermined information or the like to a computer or the like by pressing a predetermined position with a finger or a pen. When input is repeated with a finger or a pen, the resistance value of the transparent conductive film gradually changes and information or the like cannot be input accurately, and when pressing a predetermined position with the finger or pen, the transparent conductive layer of the transparent conductive film, Repeated contact and non-contact with the opposing transparent conductive layer may cause distortion, etc., which may cause problems such as Newton rings, or contact even if the finger or pen is released during contact. Has a problem that it is not contacted, that is, sticking occurs and it cannot be used.
For this reason, forming the coating layer of the organic resin containing a filler and forming a transparent conductive layer on it is also proposed.
However, when a transparent conductive film is formed through a coating layer of an organic resin containing a filler, there is an effect of preventing Newton's ring, but the adhesion between the coating layer and the transparent conductive film is insufficient, or organic The resin coating layer is inferior in input durability because the film hardness is weak, especially those with surface roughness above a certain level, such as those with inferior scratch resistance, input durability and solvent resistance. It was almost.
[0003]
[Problems to be solved by the invention]
Accordingly, the present invention provides a transparent conductive film that has excellent input durability, prevents occurrence of sticking, has excellent scratch resistance, has excellent gas impermeability, and has excellent durability. .
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the invention according to claim 1 of the present invention is formed of a resin containing fine particles having an average particle diameter of 1 to 30 nm on at least one surface of the transparent substrate film (A.). A transparent layer formed by laminating an anchor layer (B.) having a center line average roughness of 4 to 20 nm, a SiOx layer (S.), and a transparent conductive layer (C.) in this order according to JIS_B_0601 A conductive film, wherein the anchor layer (B.) is a layer made of a thermosetting resin having a siloxane bond or an ionizing radiation curable resin having a siloxane bond, and has a thickness of 0.02 to 10 μm. The thickness of the SiOx layer (S.) is 2 to 25 nm.
The invention relating to the touch panel according to claim 2 of the present invention is characterized by using the transparent conductive film according to claim 1.

[0005]
DETAILED DESCRIPTION OF THE INVENTION
Although there is no restriction | limiting in particular as a base film (A.) used for this invention, It is preferable to use the film which has high transparency from the viewpoint of processability and use, for example, cellulose triacetate, acetate etc. It is preferable to use a resin film such as a cellulose resin, a polyester resin such as polyethylene terephthalate or polyethylene naphthalate, an acrylic resin such as polymethyl methacrylate, a polycarbonate resin, or a polysulfone resin.
Although the thickness of these films is not particularly limited, those having a thickness of 12 to 300 μm are preferably used.
[0006]
The anchor layer (B.) used in the present invention is not particularly limited in the resin of the layer structure, but preferably the layer after formation is improved in adhesion with a transparent conductive film or transparent. Those that contribute to improvement and have excellent affinity with fine particles are preferred.
The resin and other constituent components forming the anchor layer (B.) are mainly thermosetting resins or ionizing radiation curable resins, and are not particularly limited as long as they have the functions described above. Alcohol-modified polyfunctional compound, trimethylolpropane acrylate, tripropylene glycol diacrylate, pentaerythritol triacrylate, 1,6-hexanediol acrylate, titanate compound, alkoxysilane hydrolysis condensation resin (siloxane bond-containing resin) Is mentioned. Of these, alkoxysilane hydrolytic condensation components (siloxane bond-containing resins) can be preferably used.
Although the thickness of an anchor layer (B.) is not specifically limited, From the balance of transparency and durability, it is the range of 0.02-10 micrometers.
The ionizing radiation curable resin is formed from a paint containing at least a resin that is cured by electron beam or ultraviolet irradiation. Specifically, it contains a photopolymerizable prepolymer, a photopolymerizable monomer, a photopolymerization initiator, and further contains additives such as sensitizers, non-reactive resins, leveling agents, and solvents as necessary. It is.
[0007]
In the present invention, in order to obtain a transparent conductive film excellent in input durability, preventing occurrence of sticking and excellent in scratch resistance, the center line average roughness with Ra of 4 to 20 nm (according to JIS B 0601, the following) It is necessary to form an anchor layer (B.) having the same), and this Ra is preferably 5 to 10 nm, and for this purpose, particles of fine particles having an average particle diameter of 1 to 30 nm to be contained in a component such as a resin The diameter needs to be an average particle diameter of 1 to 30 nm. When Ra is less than 4 nm, the effect of preventing the occurrence of sticking is insufficient, and when Ra exceeds 20 nm, even if it has the effect of preventing the occurrence of sticking, scratch resistance, input durability, solvent resistance Is inferior.
[0008]
The fine particles used in the present invention are not particularly limited, and examples thereof include silica, silicone resin particles, acrylic resin particles, styrene resin particles, nylon resin particles, etc., but the fine particles include handling properties and adhesion to a transparent conductive film. In view of the properties, a metal oxide sol prepared from a hydrolyzate of a metal alkoxide, in which inorganic oxide fine particles are dispersed in a colloidal form is preferable. The colloidally dispersed fine particles are more preferably stabilized using a dispersant or the like. Examples of the inorganic oxide fine particles include silicon oxide, antimony oxide, tin oxide, indium oxide, zinc oxide, alumina, titania, zirconia and the like. Of these, colloidal silica in which silicon oxide is dispersed is preferable in view of price and color. In order to enhance the conductive effect of the transparent conductive layer, tin oxide, antimony oxide-tin oxide, or the like can be suitably used.
The shape of the particles is preferably spherical or nearly spherical, but is not particularly limited. The addition amount of the fine particles is not particularly limited, but is influenced by the specific gravity of the fine particles used, but is usually in the range of 0.5 to 60% by weight, preferably 5 to 50% by weight of the resin solid content.
[0009]
In the present invention, the SiOx layer (S.) may be provided on the side of the transparent base film (A.) where the anchor layer (B.) and the transparent conductive layer (C.) are provided, or on the opposite side. Although it is good, it is preferably formed between the anchor layer (B.) and the transparent conductive layer (C.).
x is preferably 1.5 to 2.0, and the thickness is preferably 2 to 50 nm, more preferably 5 to 15 nm. When it is less than 2 nm, the effect of forming the SiOx layer (S.) described later is slight, and when it exceeds 50 nm, it is difficult to obtain the effect of post-heat treatment for improving the transparency of the transparent conductive layer (C.). Such problems arise, and it is not economically advantageous.
The method for forming the SiOx layer (S.) is not particularly limited, and a known method such as an electron beam vapor deposition method, a heat vapor deposition method, or a sputtering method is appropriately selected and adopted. By forming this SiOx layer (S.), the transparency of the resulting transparent conductive film is improved and it can withstand pen input, etc. Further, it is considered that the transparent conductivity is considered to be due to the water vapor barrier property of the SiOx layer (S.). Durability is also improved by suppressing deterioration of the layer (C.).
The present invention provides an anchor layer (B) having Ra of 4 to 20 nm and a center line average roughness formed of a resin containing fine particles having an average particle diameter of 1 to 30 nm on at least one surface of a transparent substrate film (A.). .), A SiOx layer (S.), and a transparent conductive layer (C.) are provided. The anchor layer (B.) is formed on one surface of the transparent base film (A.). In the case where the SiOx layer (S.) and the transparent conductive layer (C.) are sequentially provided, a hard coat layer may be provided on the other surface of the transparent base film (A.), and further on the hard coat layer. A silicon-fluorine antifouling layer may be provided, or a hard coat layer or other layer may be provided between the transparent substrate film (A.) and the anchor layer (B.).
[0010]
The hard coat layer as used in the present invention has a pencil hardness of H or more, and the hard coat layer formation is not particularly limited, and examples thereof include a resin thermosetting resin or an ionizing radiation curable resin, and a melamine resin. , Acrylate-based alcohol-modified polyfunctional compounds, trimethylolpropane acrylate, tripropylene glycol diacrylate, pentaerythritol triacrylate, 1,6-hexanediol acrylate, titanate-based compounds, alkoxysilane hydrolytic condensation resins (including siloxane bonds) Resin). For example, as a method for forming a hard coat layer using an ionizing radiation paint, a normal coating method such as bar, blade, spin, gravure, spray or the like can be used.
[0011]
As the transparent conductive layer (C.) in the present invention, a coating layer mainly composed of an inorganic oxide formed by coating a hydrolyzate such as a metal alkoxide, or CVD, EB deposition, ion plating. Indium-tin (ITO), ZnO 2, CdO, SnO 2, etc. are appropriately selected and used.
Among them, indium-tin system (ITO) is preferable, and indium-tin system (ITO) in which the content of tin is 5 to 15 mol% is particularly preferable. It may be crystalline, crystalline, or of course non-crystalline-crystalline intermediate (mixed type).
Thus, although the obtained transparent conductive film is used for the field | area and apparatus which require various transparent conductivity, it can be used conveniently as a transparent electrode of a touch panel especially.
[0012]
【Example】
Hereinafter, the present invention will be described in more detail by way of examples. * Example 1
A coating consisting of 50 parts of hexafunctional acrylate monomer, 31 parts of bifunctional urethane acrylate, 3 parts of photoinitiator, and 100 parts of toluene on one surface of a 175 μm thick polyethylene terephthalate film has a thickness of 3 μm after curing of the hard coat resin binder part. After coating with a Mayer bar, the solvent was dried, and then cured by irradiating 300 mJ / cm ^{2 of} ultraviolet light with a high-pressure mercury lamp to form a hard coat layer (the pencil hardness of the hard coat layer was 2H).
On the surface opposite to the surface of the polyethylene terephthalate film provided with the hard coat layer, a hydrolyzate of alkoxysilane (the same siloxane bond-containing resin component content as in Example 1), cyclohexanone, methyl isobutyl ketone, organo having an average particle diameter of 12 nm A mixed solution (solid content ratio, siloxane bond-containing resin component: organosilica sol component = 5.2: 4.8 weight ratio) of silica sol methyl isobutyl ketone dispersion (the same siloxane bond-containing resin component content as in Example 1) was kiss coated. Was applied to form an anchor layer having a dry thickness of 0.02 μm. Ra of the anchor layer was 7.57 nm (Rz was 56.3 nm, measurement range was 500 μm).
A thin film of 10 nm sputtering of SiO ₂ is formed on the anchor coat layer, an ITO film is used as a transparent conductive layer on the SiO ₂ thin film, and a target of indium: tin = 90: 10 (metal, molar ratio) is used. Then, the inside of the vacuum chamber is set to 10-3 Pa, and a mixed gas of Ar and O2 is introduced to form 5 × 10-1 Pa to a thickness of 30 nm by DC sputtering, and heat treatment is performed at 150 ° C. for 24 hours to obtain a transparent conductive film. It was. The resistance value of the ITO film of this transparent conductive film was 470Ω / □, and the total light transmittance was 85.3%.
The obtained transparent conductive film is cut into a size of 10 cm × 15 cm, the two pieces are placed so that the ITO films face each other, the ends are fixed, and fixed on a glass plate, and a hard coat of one polyethylene terephthalate film Drawing was performed at a speed of 10 cm / sec while pressing with a pressure of 1 Kg / cm ² at the circular end (1 cm ² area) of the polyacetal resin rod from the layer side. There was no sticking (sticking) between the ITO films due to this drawing, no change in the appearance of the ITO film was seen, and there was no problem in input durability and solvent resistance.
[0013]
* Example 2
A transparent conductive film was obtained in the same manner as in Example 1 except that Ra of the anchor layer was 7.12 nm (Rz was 66.3 nm, measurement range was 500 μm).
The obtained transparent conductive film is cut into a size of 10 cm × 15 cm, the two pieces are placed so that the ITO films face each other, the ends are fixed, and fixed on a glass plate, and a hard coat of one polyethylene terephthalate film Drawing was performed at a speed of 10 cm / sec while pressing with a pressure of 1 Kg / cm ² at the circular end (1 cm ² area) of the polyacetal resin rod from the layer side. There was no sticking (sticking) between the ITO films due to this drawing, no change in the appearance of the ITO film was seen, and there was no problem in input durability and solvent resistance.
[0014]
* Example 3
A transparent conductive film was obtained in the same manner as in Example 1 except that Ra of the anchor layer was 4.12 nm (Rz was 46.3 nm, measurement range was 500 μm).
The obtained transparent conductive film is cut into a size of 10 cm × 15 cm, the two pieces are placed so that the ITO films face each other, the ends are fixed, and fixed on a glass plate, and a hard coat of one polyethylene terephthalate film Drawing was performed at a speed of 10 cm / sec while pressing with a pressure of 1 Kg / cm ² at the circular end (1 cm ² area) of the polyacetal resin rod from the layer side. Although very little sticking (sticking) between the ITO films due to this drawing was observed, there was no change in the appearance of the ITO film, and there was no problem in input durability and solvent resistance.
[0015]
* Example 4
A coating consisting of 50 parts of hexafunctional acrylate monomer, 31 parts of bifunctional urethane acrylate, 3 parts of photoinitiator, and 100 parts of toluene on one surface of a 175 μm thick polyethylene terephthalate film has a thickness of 3 μm after curing of the hard coat resin binder part. After coating with a Mayer bar, the solvent was dried, and then cured by irradiating 300 mJ / cm ^{2 of} ultraviolet light with a high-pressure mercury lamp to form a hard coat layer (the pencil hardness of the hard coat layer was 2H).
On the surface opposite to the surface of the polyethylene terephthalate film provided with the hard coat layer, an alkoxysilane hydrolyzate (siloxane bond-containing resin component 28.5% by weight), cyclohexanone, methyl isobutyl ketone, organosilica sol having an average particle size of 12 nm A mixed liquid of methyl isobutyl ketone dispersion (organosilica sol component 30% by weight) (solid content ratio, siloxane bond-containing resin component: organosilica sol component = 4: 1 weight ratio) was applied by kiss coating and dried to a thickness of 0.03 μm. An anchor layer was formed. The anchor layer had an Ra of 9.62 nm (Rz (according to JIS B 0601, hereinafter the same) was 84.1 nm, and measurement range was 500 μm).
A thin film of 10 nm of SiO ₂ is formed on the anchor coat layer, an ITO film is formed on the SiO ₂ thin film as a transparent conductive layer, and a target of indium: tin = 90: 10 (oxide, molar ratio) is formed. The vacuum chamber was set to 10-3 Pa, and a mixed conductive gas of Ar and O2 was introduced to form 5 × 10-1 Pa to a thickness of 30 nm by DC sputtering to obtain a transparent conductive film. The resistance value of the ITO film of this transparent conductive film was 257 Ω / □, and the total light transmittance was 84.9%.
The obtained transparent conductive film is cut into a size of 10 cm × 15 cm, the two pieces are placed so that the ITO films face each other, the ends are fixed, and fixed on a glass plate, and a hard coat of one polyethylene terephthalate film Drawing was performed at a speed of 10 cm / sec while pressing with a pressure of 1 Kg / cm ² at the circular end (1 cm ² area) of the polyacetal resin rod from the layer side. There was no sticking (sticking) between the ITO films due to this drawing, no change in the appearance of the ITO film was seen, and there was no problem in input durability and solvent resistance.
[0016]
* Comparative Example 1
A coating consisting of 50 parts of hexafunctional acrylate monomer, 31 parts of bifunctional urethane acrylate, 3 parts of photoinitiator, and 100 parts of toluene on one surface of a 175 μm thick polyethylene terephthalate film has a thickness of 3 μm after curing of the hard coat resin binder part. After coating with a Mayer bar, the solvent was dried, and then cured by irradiating 300 mJ / cm ^{2 of} ultraviolet light with a high-pressure mercury lamp to form a hard coat layer (the pencil hardness of the hard coat layer was 2H).
On the opposite side of the surface of the polyethylene terephthalate film provided with the hard coat layer, 1 kg of a hydrolyzate of alkoxysilane (siloxane bond-containing resin component), 1 kg of cyclohexanone and 5 kg of methyl isobutyl ketone (containing siloxane bond) Resin component 4.0%, organosilica sol 0%) was applied by kiss coating to form an anchor layer having a dry thickness of 25 nm. Ra of the anchor layer was 2.90 nm (Rz was 23.0 nm, measurement range was 500 μm).
On this anchor coat layer, an ITO film is used as a transparent conductive layer, a target of indium: tin = 90: 10 (oxide, molar ratio) is used, the vacuum chamber is set to 10 −3 Pa, and a mixed gas of Ar and O 2 is used. While being introduced, the film was formed to a thickness of 30 nm by DC sputtering at 5 × 10 −1 Pa to obtain a transparent conductive film. The resistance value of the ITO film of this transparent conductive film was 275Ω / □, and the total light transmittance was 84.2%.
The obtained transparent conductive film is cut into a size of 10 cm × 15 cm, the two pieces are placed so that the ITO films face each other, the ends are fixed, and fixed on a glass plate, and a hard coat of one polyethylene terephthalate film Drawing was performed at a speed of 10 cm / sec while pressing with a pressure of 1 Kg / cm ² at the circular end (1 cm ² area) of the polyacetal resin rod from the layer side. It was observed that the ITO films were stuck to each other by this drawing (sticking) and did not return to the non-contact state, and part of the ITO film was damaged.
[0017]
【The invention's effect】
The transparent conductive film of the present invention is a transparent conductive film that is excellent in scratch resistance, excellent in input durability, and can prevent occurrence of sticking (no sticking between ITO films) when used in a touch panel or the like. It was.

Claims (2)

On at least one surface of the transparent substrate film (A.),
An anchor layer (B.) formed of a resin containing fine particles having an average particle diameter of 1 to 30 nm and having a center line average roughness of Ra of 4 to 20 nm according to the provisions of JIS_B_0601;
A SiOx layer (S.);
A transparent conductive layer (C.);
Are transparent conductive films formed by laminating in this order,
The anchor layer (B.) is a layer made of a thermosetting resin having a siloxane bond or an ionizing radiation curable resin having a siloxane bond, and the thickness thereof is 0.02 to 10 μm .
The thickness of the SiOx layer (S.) is 2 to 25 nm,
A transparent conductive film characterized by Using the transparent conductive film according to claim 1;
A touch panel characterized by