JP3741928B2 - 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 widely 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 contactless, 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 provided with a specific anchor layer, which has excellent input durability, prevents occurrence of sticking and has excellent scratch resistance.
[0004]
In order to solve the above problems, the invention according to claim 1 of the present invention includes at least one surface of the transparent substrate film (A) containing at least fine particles having an average particle diameter of 1 to 30 nm for preventing sticking. It is a transparent conductive film in which an anchor layer (B) formed of a resin and a transparent conductive layer (C) are provided in the order of description, and the fine particles have a resin solid content of 0.5 to 60. It is added to the resin at a ratio of% by weight, and the center line average roughness (Ra) of the anchor layer (B) is 5 to 20 nm.
The invention described in claim 2 of the present invention is characterized in that in the transparent conductive film described in claim 1, the resin constituting the anchor layer (B) contains a siloxane bond.
Invention of Claim 3 of this invention is the transparent conductive film of Claim 1 or Claim 2, The thickness of the said anchor layer (B) is 0.02-10 micrometers, It is characterized by the above-mentioned. To do.
The invention described in claim 4 of the present invention is characterized by using the transparent conductive film described in any one of claims 1 to 3.
[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 artificial resin films such as cellulose resins, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acrylic resins such as polymethyl methacrylate, and polycarbonate resins.
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 5 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 5 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]
The present invention provides an anchor layer (B) having a center line average roughness of Ra of 5 to 20 nm 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.). .) And a transparent conductive layer (C.) is provided on the anchor layer (B.), the anchor is formed on one surface of the transparent substrate film (A.). When the layer (B.) 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 silicon- A fluorine-based antifouling layer may be provided, or a hard coat layer or other layer may be provided between the transparent base 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 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, sputtering, etc. Indium-tin-based (ITO), ZnO2-based, CdO-based, SnO2-based, etc. are appropriately selected and used.
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 an electrode of a touch panel especially.
[0012]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
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 an anchor layer having a dry thickness of 20 nm 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).
On this anchor coat layer, an ITO film is used as a transparent conductive layer, a target of indium: tin = 90: 10 is used, the inside of the vacuum chamber is 10 −3 Pa, and a mixed gas of Ar and O 2 is introduced, and 5 × 10 − A transparent conductive film was obtained by forming a thickness of 30 nm by DC sputtering at 1 Pa. The resistance value of the ITO film of this transparent conductive film was 217Ω / □, and the total light transmittance was 83.9%.
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.
[0013]
* Example 2
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. Then, an anchor layer having a dry thickness of 25 nm was formed. Ra of the anchor layer was 7.57 nm (Rz was 56.3 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 is used, the inside of the vacuum chamber is 10 −3 Pa, and a mixed gas of Ar and O 2 is introduced, and 5 × 10 − A transparent conductive film was obtained by forming a thickness of 30 nm by DC sputtering at 1 Pa. The resistance value of the ITO film of this transparent conductive film was 217Ω / □, and the total light transmittance was 81.2%.
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. 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 Examples 1 and 2 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.
[0015]
* Example 4
A transparent conductive film was obtained in the same manner as in Examples 1 and 2 except that Ra of the anchor layer was 5.12 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.
[0016]
* Example 5
A transparent conductive film is obtained in the same manner except that a thin film of 10 nm of SiO ₂ is first formed on the anchor layer in Example 1 and an ITO film is formed on the SiO ₂ thin film as a transparent conductive layer. It was.
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 observed, and there was no problem in input durability and solvent resistance.
[0017]
* 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 alkoxysilane hydrolyzate (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 2.97 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 is used, the inside of the vacuum chamber is 10 −3 Pa, and a mixed gas of Ar and O 2 is introduced, and 5 × 10 − A transparent conductive film was obtained by forming a thickness of 30 nm by DC sputtering at 1 Pa. The resistance value of the ITO film of this transparent conductive film was 215Ω / □, 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.
[0018]
【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 the occurrence of sticking (no sticking between ITO films) when used for a touch panel or the like. It was.

Claims (4)

  On at least one surface of the transparent substrate film (A),
  at least,
  An anchor layer (B) formed of a resin containing fine particles having an average particle diameter of 1 to 30 nm for preventing sticking;
  A transparent conductive layer (C);
  Is a transparent conductive film provided in the order of description,
  The fine particles are added to the resin at a ratio of 0.5 to 60% by weight of the resin solid content,
  The center line average roughness (Ra) of the anchor layer (B) is 5 to 20 nm,
  A transparent conductive film characterized by   The transparent conductive film according to claim 1,
  The resin constituting the anchor layer (B) includes a siloxane bond;
  A transparent conductive film characterized by In the transparent conductive film according to claim 1 or 2,
The anchor layer (B) has a thickness of 0.02 to 10 μm;
A transparent conductive film characterized by   Using the transparent conductive film according to any one of claims 1 to 3,
  A touch panel characterized by