JP6626709B2 - ITO conductive film and paint for forming the ITO conductive film - Google Patents

Description

  The present invention is an LCD (Liquid Crystal Display) or PDP (Plasma Display Panel), an organic EL (ElectroLuminescence), an ITO conductive film constituting a transparent electrode used in a display device such as a touch panel, and for forming this ITO conductive film It relates to paint. In the present specification, ITO refers to indium tin oxide (Indium Tin Oxide).

  Conventionally, this type of ITO conductive film is formed by coating a coating material for forming an ITO conductive film on the surface of a base material sheet and drying it. When winding the ITO conductive film formed on the surface of the substrate sheet, or when pressing the ITO conductive film together with the substrate sheet through a pair of calender rolls, the substrate with the surface of the ITO conductive film wound up In order to prevent adhesion to the back surface of the sheet or the calendar roll, and to prevent contamination or damage of the ITO conductive film surface from the back surface of the base sheet or the calendar roll, a release treatment is performed before winding or calendering. Protective film or cover film is laminated on the surface of the ITO conductive film. Then, when using the ITO conductive film or after pressing, the protective film or the cover film is peeled off from the surface of the ITO conductive film (for example, see Patent Document 1). The former protective film is, for example, a protective film that is peeled off immediately before application when the ITO conductive film is attached to the display surface of a mobile phone with the base sheet facing upward.

  The protective film or cover film subjected to the release treatment is usually formed on the surface of a base film such as a polyester film by a silicone resin or a film surface of a non-silicone resin such as a long-chain alkyl group-containing compound or an olefin resin. A layer made of an adjusting agent (release agent) is formed (for example, see Patent Document 2).

JP 2015-162325 A (paragraphs [0040] to [0042], FIG. 1B) JP 2007-203588 A (paragraphs [0002] and [0006])

  However, after laminating the protective film or cover film described in Patent Document 2 on the surface of the ITO conductive film, when the protective film or cover film is peeled off, there is a problem that a part of the surface layer of the ITO conductive film is peeled off. Was. In addition, there is a problem that the silicone resin as a film surface conditioner (release agent) on the surface of the base film migrates into the ITO conductive film, and deteriorates the conductivity and transparency of the ITO conductive film.

  A first object of the present invention is to form an ITO conductive film and a method of forming the ITO conductive film, wherein a surface layer of the ITO conductive film is not peeled off when the protective film on the surface of the ITO conductive film is peeled and the ITO conductive film is used. It is to provide a paint for. A second object of the present invention is to provide an ITO conductive film having both good conductivity and transparency, and a paint for forming the ITO conductive film.

According to a first aspect of the present invention, in an ITO conductive film in which ITO particles are uniformly dispersed in a binder resin, 70 to 90% by mass of the ITO particles in 100% by mass of the ITO conductive film, The ITO particles have a specific surface area of 40 to 65 m ² / g by a BET method and an L value of 37 or less, each containing 3% by mass or less of an amphoteric nitrogen-containing fluorine-based compound represented by the following formula (1). It is characterized by.

However, in the formula (1), Rf ¹ and Rf ² are the same or different, each having 1 to 6 carbon atoms and being a linear or branched perfluoroalkyl group. Rf ³ is a linear or branched perfluoroalkylene group having 1 to 6 carbon atoms. R is a linking group that is a divalent organic group, and X is an amphoteric type hydrophilicity-imparting group.

According to a second aspect of the present invention, there is provided a coating for forming an ITO conductive film containing ITO particles, a binder resin, and a solvent. 0.3% by mass or less each of the amphoteric nitrogen-containing fluorine-based compound represented by the formula (1), and 10% to 30% by mass of components other than the ITO particles in 100% by mass of the solid content of the paint, The ITO particles have a specific surface area according to a BET method of 40 to 65 m ² / g and an L value of 37 or less.

  In the ITO conductive film according to the first aspect of the present invention, ITO particles are uniformly dispersed in a binder resin, and a specific amphoteric nitrogen-containing fluorine-based compound is used as a film surface modifier at a ratio of 3% by mass or less. Therefore, when the protective film is peeled off from the surface of the ITO conductive film, the surface layer of the ITO conductive film does not peel off. Further, since the amphoteric nitrogen-containing fluorine-based compound is conductive, it does not lower the conductivity of the ITO conductive film, and because of the amphoteric ions, it hardly acts on the surface charge of the ITO particles. As a result, the ITO particles are not aggregated and the transparency of the ITO conductive film is not reduced. Furthermore, since the ITO conductive film contains 70 to 90% by mass of ITO particles having a predetermined specific surface area and an L value, it is possible to have both good conductivity and transparency.

  In the paint for forming an ITO conductive film according to the second aspect of the present invention, the amphoteric nitrogen-containing fluorine-containing compound as a film surface conditioner contained in the paint contains a low surface tension during drying of the coating film. Precipitates on the surface layer of. For this reason, after laminating a protective film with a release agent layer on the surface of the ITO conductive film formed by this paint, when the protective film is peeled off from the surface, the protective film is easily peeled off from the surface of the ITO conductive film, Even when the amphoteric nitrogen-containing fluorine-containing compound is contained in an amount of 0.3% by mass or less, the compound has the above-described characteristics, and thus does not adversely affect the conductivity and transparency of the ITO conductive film. Furthermore, since the coating material for forming an ITO conductive film contains 3 to 45% by mass of ITO particles having a predetermined specific surface area and an L value, when the ITO conductive film is formed, it can have both good conductivity and transparency. Further, by containing 10 to 30% by mass of components other than the ITO particles containing the binder resin in the solid content of the paint, the adhesion of the ITO conductive film to the substrate is excellent.

  Next, an embodiment for carrying out the present invention will be described.

[Coating for forming ITO conductive film]
The coating material for forming an ITO conductive film according to the present embodiment contains 0.3% by mass of an amphoteric nitrogen-containing fluorine-based compound as a film surface conditioner in 100% by mass of the coating material in addition to the ITO particles, the binder resin, and the solvent. The following is further included. 100% by mass of the paint contains 3 to 45% by mass of ITO particles, and 100% by mass of the solid content of the paint contains 10 to 30% by mass of components other than the ITO particles. The amphoteric nitrogen-containing fluorine-based compound is contained as a film surface conditioner because the amphoteric nitrogen-containing fluorine-based compound does not lower the conductivity of the ITO conductive film because it has conductivity, and the surface charge of the ITO particles. This is because they do not readily act and do not agglomerate the ITO particles and do not lower the transparency of the ITO conductive film. On the other hand, in the cationic and anionic nitrogen-containing fluorine-based compounds, since the cation ion and the anion ion easily act on the surface charge of the ITO particles, the ITO particles are easily aggregated, and the transparency of the ITO conductive film is reduced.

The ITO particles in the paint have a specific surface area by the BET method of 40 to 65 m ² / g and an L value of 37 or less. If the specific surface area by the BET method is less than 40 m ² / g, the haze of an ITO conductive film having a desired surface resistivity increases, and the transparency of the film decreases. If the content of the ITO particles in the film is reduced to reduce the haze, the desired surface resistivity of the film cannot be obtained, and the conductivity of the film deteriorates. Originally, when the BET value is high, the particles become small, so that transparency and haze can be reduced. However, when the specific surface area by the BET method exceeds 65 m ² / g, a predetermined dispersing agent is used. When the ITO particles are mixed with the resin in the amount of (1), the dispersion of the ITO particles in the resin becomes insufficient, and the haze of the coating film deteriorates. When ITO particles exceeding 65 m ² / g are used to reduce haze in order to avoid this, it is necessary to increase the amount of a dispersant for dispersing the ITO particles in the resin. When the amount of the dispersing agent is increased, problems such as deterioration of the conductivity of the film and deterioration of the adhesion to the substrate occur. Therefore, the upper limit of the specific surface area of the ITO particles by the BET method is set to 65 m ² / g. When the content of the ITO particles in the film is increased in order to obtain a desired surface resistivity, the adhesion of the ITO conductive film to the substrate when the paint for forming the ITO conductive film is applied on the substrate is increased. become worse.

  When the L value of the ITO particles exceeds 37, the reduction of the ITO is insufficient, so that the surface resistivity of the film increases and the conductivity of the film deteriorates. Further, since the size of the particles increases, the haze of the film increases and the transparency of the film decreases.

  The binder resin in the paint preferably contains 10 to 35% by mass in the ITO conductive film. The binder resin is not particularly limited, but when ethyl cellulose and terpene phenol resin are used, the mass ratio of ethyl cellulose to terpene phenol resin is such that ethyl cellulose: terpene phenol resin = 10-80: 90-20. This is preferable from the viewpoint of increasing the adhesion of the polymer to the substrate. Examples of the terpene phenol resin include Sylvalite TP7042 (softening point: 145 ° C) manufactured by Arizona Chemical Co., Ltd., Tamanol 803L (softening point: 140 to 160 ° C), 901 (softening point: 120 to 135 ° C) manufactured by Arakawa Chemical Industries, and Yashara Chemical. YS Polystar T160 (softening point: 160 ° C), 145 (softening point: 145 ° C), T130 (softening point: 130 ° C), U130 (softening point: 130 ° C), S145 (softening point: 145 ° C), G150 (Softening point: 150 ° C.), K140 (softening point: 140 ° C.), TH130 (softening point: 130 ° C.) and the like.

  As described above, the paint for forming an ITO conductive film is prepared by mixing ITO particles, a binder resin, an amphoteric nitrogen-containing fluorine-based compound, and a solvent. A dispersant may be mixed in the paint. By mixing the dispersant, the transparency of the coating film is further improved. This paint contains 3 to 45% by mass, preferably 4 to 40% by mass of ITO particles in 100% by mass of the paint. Further, it is prepared so as to contain 10 to 30% by mass, preferably 15 to 25% by mass, of components other than ITO particles in 100% by mass of the solid content. Further, this paint is prepared so as to further contain 0.3% by mass or less, preferably 0.01 to 0.2% by mass, of the amphoteric nitrogen-containing fluorine-based compound in 100% by mass of the paint.

  When the content of the ITO particles in the paint is less than 3% by mass, the conductivity of the ITO conductive film made from the paint does not increase. On the other hand, if the content exceeds 45% by mass, the stability with time, such as thickening of the paint, is deteriorated. Moreover, the binder resin is relatively short, the adhesion between the ITO particles is reduced, and the surface resistivity of the ITO conductive film is deteriorated.

  If the content of components other than the ITO particles in the solid content of the paint is less than 10% by mass, sufficient adhesion of the ITO conductive film to the substrate cannot be obtained. On the other hand, if the content exceeds 30% by mass, the surface resistivity of the ITO conductive film deteriorates, and the conductivity decreases.

  Further, when the content of the amphoteric nitrogen-containing fluorine-based compound in the coating exceeds 0.3% by mass, the coating is thickened, the temporal stability is deteriorated, and the surface resistivity and the conductivity of the ITO conductive film are reduced. .

  The nitrogen-containing fluorine-based compound as a film surface conditioner of the present embodiment is an amphoteric type represented by the following formula (1).

In the above formula (1), Rf ¹ and Rf ² are the same or different, each having 1 to 6 carbon atoms and being a linear or branched perfluoroalkyl group. Rf ³ is a linear or branched perfluoroalkylene group having 1 to 6 carbon atoms. Each of Rf ¹ and Rf ² preferably has 2 to 5 carbon atoms.

  In the above formula (1), R is a linking group that is a divalent organic group. R may be a linear or branched organic group. R may or may not include one or more bonds selected from an ether bond, an ester bond, an amide bond, and a urethane bond in the molecular chain.

In the above formula (1), X is an amphoteric type hydrophilicity-imparting group having any one of terminals of a carbobetaine type, a sulfobetaine type, an amine oxide type and a phosphobetaine type. Since the nitrogen-containing fluorine-based compound is of the amphoteric type, the hydrophilicity-imparting group X has a carbobetaine-type “-N ⁺ R ⁸ R ⁹ (CH ₂ ) _n CO ₂ ⁻ ” and a sulfobetaine-type “-” at the terminal. _{^{n + R 8 R 9 (CH}} 2) n SO 3 - ", of the amine oxide type" ^-N + ^R 8 ^R 9 O ^- "or phosphobetaine type" _{^{-OPO 3 - (CH 2) n}} n + R 8 R ⁹ R ¹⁰ ”(n is an integer of 1 to 10, preferably 1 to 5, R ⁸ and R ⁹ are a hydrogen atom or an alkyl group having 1 to 10, preferably 1 to 5 carbon atoms, R ¹⁰ is a hydrogen atom or Alkyl having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms Or an alkylene group having 1 to 10, preferably 1 to 5 carbon atoms).

  Examples of the amphoteric nitrogen-containing fluorine-based compound represented by the above formula (1) include a carbobetaine-type compound represented by the following formula (2) and a sulfobetaine-type compound represented by the following formulas (3) to (5) , An amine oxide type compound represented by the formula (6), and a phosphobetaine type compound represented by the formula (7).

  -Carbobetaine type compound represented by the formula (2)

  ・ Sulfobetaine type compound represented by formula (3)

  ・ Sulfobetaine type compound represented by formula (4)

  ・ Sulfobetaine type compound represented by formula (5)

  -Amine oxide type compound represented by the formula (6)

  -Phosphobetaine type compound represented by the formula (7)

  In addition to the amphoteric type, the nitrogen-containing fluorine-based compound includes an anionic nitrogen-containing fluorine-containing compound represented by the following formula (8) and a cationic nitrogen-containing fluorine-containing compound represented by the following formula (9). I do.

  ・ Anionic compound represented by formula (8)

  ・ Cation type compound represented by formula (9)

  Although the solvent in the paint is not particularly limited, 3-methoxy-3-methyl-1-butanol (hereinafter, referred to as MMB) is mainly used as the solvent. 3-methoxy-3-methyl-1-butanol has a relatively high boiling point and is water-soluble, so that it can be used as a mixed solvent of water, and it is easy to disperse the ITO particles. It is possible to improve the optical characteristics of the film. Since the solvent in the coating is required to dry quickly, 2-butanone, 4-methyl-2-pentanone, ethanol, 2-propanol, 1-butanol, toluene, methanol, 1-propanol, ethyl acetate, acetic acid having a low boiling point are used. It is preferable to use butyl, acetone, 2,4-pentanedione, xylene, or the like in combination with 3-methoxy-3-methyl-1-butanol. The content of the solvent is preferably 45 to 95% by mass in 100% by mass of the coating material.

  The dispersant in the paint is preferably contained in an amount of 1 to 10 parts by mass based on 100 parts by mass of the ITO particles. As an example of the dispersant, any dispersant for a pigment can be used as long as the pigment can be stably dispersed in fine particles. Specifically, ammonium polyoxyethylene styrenated phenyl ether sulfate, sodium polyoxyalkylene decyl ether sulfate, sodium polyoxyethylene tridecyl ether sulfate, ammonium polyoxyethylene isodecyl ether sulfate, sodium polyoxyethylene lauryl ether sulfate, polyoxyethylene Alkyl ether sulfates such as ammonium lauryl ether sulfate, sodium polyoxyethylene alkyl ether sulfate, ammonium polyoxyethylene oleyl cetyl ether sulfate, sodium polyoxyethylene oleyl cetyl ether sulfate, alkyl sulfate ester salts, alkyl benzene sulfonate, alkyl phthalene sulfonic acid Salt, polyoxyethylene alkyl ether phosphate, polyoxy Alkyl phosphates such as ethylene alkyl ether phosphate, polyoxyethylene lauryl ether phosphate, polyoxyethylene alkyl ether phosphate, polyoxyethylene tridecyl ether phosphate, polyoxyethylene styrenated phenyl ether phosphate, etc. Ester salts, polyoxyethylene alkyl ether acetates, alkyl ether acetates such as sodium polyoxyethylene lauryl ether acetate, disodium lauryl sulfosuccinate, disodium polyoxyethylene alkyl sulfosuccinate, disodium lauryl polyoxyethylene sulfosuccinate, polyoxy Alkyl succinates such as ethylene alkyl sulfosuccinates, anionic surfactants such as polycarboxylic acid type polymers, amine oxides Cationic surfactants, polyoxyethylene block copolymers, surfactants, such as non-ionic surfactants such as polyoxyethylene alkyl amides. When the content of the dispersant is less than 1 part by mass, the dispersion of the coating material for forming the ITO conductive film becomes insufficient, and the transparency of the coating film tends to be insufficient. If it exceeds 10 parts by mass, the conductivity of the ITO conductive film and the adhesion of the coating film are likely to be adversely affected.

[ITO conductive film]
The ITO conductive film of the present embodiment has ITO particles uniformly dispersed in a binder resin and contains an amphoteric nitrogen-containing fluorine-based compound as a film surface modifier. This ITO conductive film contains 70 to 90% by mass of ITO particles in the ITO conductive film, the ITO particles have a specific surface area by a BET method of 40 to 65 m ² / g, an L value of 37 or less, and a binder resin. And 3% by mass or less, preferably 0.1 to 2% by mass of an amphoteric nitrogen-containing fluorine-based compound.

  When the content of the ITO particles in the ITO conductive film is less than 70% by mass, the conductivity of the ITO conductive film is not improved. If this content exceeds 90% by mass, the binder resin becomes relatively insufficient, the adhesion between the ITO particles decreases, and the surface resistivity of the ITO conductive film deteriorates. The critical significance of each numerical range of the specific surface area and the L value of the ITO particles in the ITO conductive film by the BET method is the same as the critical significance of each of these numerical ranges in the paint. If the amphoteric nitrogen-containing fluorine-based compound in the ITO conductive film exceeds 3% by mass, the surface resistivity and the conductivity of the ITO conductive film are reduced.

  The ITO conductive film of the present embodiment is obtained by, for example, applying the above-mentioned paint for forming an ITO conductive film on a polyester film such as polyethylene terephthalate (PET), polybutylene terephthalate, or polyethylene naphthalate by a screen printing method or a bar. It is formed by applying by a coating method, a die coating method, a doctor blade, a spinning method or the like, and then drying at a temperature of 60 to 130 ° C.

  Next, examples of the present invention will be described in detail together with comparative examples.

<Example 1>
ITO particles (P2-ITO manufactured by Mitsubishi Materials Corporation) having a specific surface area of 43 m ² / g by a BET method and an L value of 30 are prepared, and 100 g of the ITO particles is mixed with 5 g of a polyoxyethylene alkyl ether phosphate ester dispersant. The mixture was added to a mixture of 145 g of MMB and a solvent, and dispersed by a bead mill disperser to obtain an ITO dispersion. The particle size of the ITO particles in the ITO dispersion was 50 nm as measured by LB-550 manufactured by Horiba, Ltd. 10.38 g of the obtained ITO dispersion, 0.19 g of ethyl cellulose, and 0.44 g of a terpene phenol resin were mixed with 38.78 g of a solvent in which MMB and methyl isobutyl ketone (MIBK) were mixed at a ratio of 1: 2. Finally, 0.007 g (the content in the coating material is 0.014% by mass) of a sulfobetaine type compound of the amphoteric nitrogen-containing fluorine compound represented by the above formula (3) is added and mixed as a film surface conditioner, and ITO is mixed. A paint for forming a conductive film was prepared. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Example 2>
As a film surface conditioner, 0.008 g of the sulfobetaine compound represented by the above formula (3) as in Example 1 (content in the coating material: 0.016% by mass) was added and mixed. Except for this, the paint for forming an ITO conductive film was prepared in the same manner as in Example 1. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Example 3>
The same sulfobetaine type compound represented by the above formula (3) as in Example 1 was added as a film surface conditioner in the coating material in an amount of 0.013 g (0.025% by mass in the coating material) and mixed. Except for this, the paint for forming an ITO conductive film was prepared in the same manner as in Example 1. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Example 4>
0.008 g (content in the coating material: 0.016% by mass) of a sulfobetaine type compound represented by the above formula (5) was added and mixed as a film surface conditioner. Except for this, the paint for forming an ITO conductive film was prepared in the same manner as in Example 1. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Example 5>
As a film surface conditioner, 0.008 g of the sulfobetaine type compound represented by the above formula (4) (the content in the coating material was 0.016% by mass) was added and mixed. Except for this, the paint for forming an ITO conductive film was prepared in the same manner as in Example 1. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Example 6>
As a film surface conditioner, 0.008 g of the carbobetaine type compound represented by the above formula (2) (the content in the coating material was 0.016% by mass) was added and mixed. Except for this, the paint for forming an ITO conductive film was prepared in the same manner as in Example 1. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Example 7>
10.38 g of the ITO dispersion obtained in Example 1, 0.16 g of ethyl cellulose, and 0.38 g of a terpene phenol resin were mixed with 38.78 g of a solvent obtained by mixing MMB and MIBK at a ratio of 1: 2. Finally, 0.100 g of sulfobetaine type compound of the amphoteric type nitrogen-containing fluorine compound represented by the above formula (3) as a film surface conditioner (the content in the paint is 0.200% by mass) is added and mixed, and ITO is added. A paint for forming a conductive film was prepared. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

Example 8
0.008 g (content in the coating material: 0.016% by mass) of the amine oxide type compound represented by the above formula (6) was added and mixed as a film surface conditioner. Except for this, the paint for forming an ITO conductive film was prepared in the same manner as in Example 1. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Example 9>
As a film surface conditioner, 0.008 g of the phosphobetaine type compound represented by the above formula (7) (the content in the coating material was 0.016% by mass) was added and mixed. Except for this, the paint for forming an ITO conductive film was prepared in the same manner as in Example 1. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Example 10>
10.38 g of the ITO dispersion obtained in Example 1, 0.15 g of ethyl cellulose, and 0.34 g of a terpene phenol resin were mixed with 38.78 g of a solvent obtained by mixing MMB and MIBK at a ratio of 1: 2. Finally, 0.150 g of a sulfobetaine type compound of the amphoteric type nitrogen-containing fluorine compound represented by the above formula (3) represented by the above formula (3) (the content in the paint is 0.300% by mass) is added and mixed as a film surface modifier, and ITO is added. A paint for forming a conductive film was prepared. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Example 11>
ITO particles having a specific surface area by the BET method of 40 m ² / g and an L value of 37 are prepared, and 100 g of the ITO particles is mixed with a mixed solution of 5 g of a polyoxyethylene alkyl ether phosphate ester dispersant and 95 g of a solvent MMB. The resulting mixture was dispersed by a bead mill disperser to obtain an ITO dispersion. The particle size of the ITO particles in the ITO dispersion was 58 nm as measured by LB-550 manufactured by Horiba, Ltd. 44.82 g of the obtained ITO dispersion, 3.38 g of an acrylic resin (Viscoat 802 manufactured by Osaka Organic Chemical Industry), and 0.27 g of a photopolymerization initiator (Irgacure 184 manufactured by BASF) were mixed with MMB and MIBK at a ratio of 1: 2. It was mixed with 0.59 g of the mixed solvent. Finally, 0.150 g of a sulfobetaine compound of the amphoteric nitrogen-containing fluorine compound represented by the above formula (3) (the content in the coating material is 0.081% by mass) was added and mixed as a film surface conditioner, and ITO was mixed. A paint for forming a conductive film was prepared. The content of the ITO particles in the paint was 44.8% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Example 12>
ITO particles having a specific surface area of 65 m ² / g by the BET method and an L value of 22 are prepared, and 100 g of the ITO particles is mixed with a mixed solution of 5 g of a polyoxyethylene alkyl ether phosphate ester-based dispersant and 145 g of a solvent MMB. The resulting mixture was dispersed by a bead mill disperser to obtain an ITO dispersion. The particle diameter of the ITO particles in the ITO dispersion was 48 nm as measured by LB-550 manufactured by Horiba, Ltd. Using 4.15 g of the obtained ITO dispersion liquid, 0.40 g of an epoxy resin (Yukaresin NE-002, manufactured by Yoshimura Oil Chemical Co., Ltd.) and 0.05 g of a curing agent (Yukaresin H-40, manufactured by Yoshimura Oil Chemical Co., Ltd.) as a solvent, 10.00 g of MMB was used. And 35.51 g of water were mixed. Finally, 0.003 g (the content in the coating material is 0.006% by mass) of a sulfobetaine type compound of the amphoteric type nitrogen-containing fluorine-containing compound represented by the above formula (3) is added and mixed as a film surface modifier, and ITO is mixed. A paint for forming a conductive film was prepared. The content of the ITO particles in this paint was 3.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Example 13>
26.25 g of the ITO dispersion obtained in Example 1, 11.98 g of a urethane resin (Daiichi Kogyo Seiyaku Co., Ltd., Superflex 170) were mixed with 3.00 g of MMB as a solvent and 8.23 g of water. Finally, 0.023 g of a sulfobetaine type compound of the amphoteric type nitrogen-containing fluorine compound represented by the above formula (3) (the content in the coating material is 0.045% by mass) is added and mixed as a film surface conditioner, and ITO is mixed. A paint for forming a conductive film was prepared. The content of the ITO particles in the paint was 21.0% by mass, and the content of components other than the ITO particles in the solid content of the paint was 30% by mass.

<Example 14>
ITO particles (P2-ITO manufactured by Mitsubishi Materials Corporation) having a specific surface area of 43 m ² / g by a BET method and an L value of 30 are prepared, and 100 g of the ITO particles is mixed with 5 g of a polyoxyethylene alkyl ether phosphate ester dispersant. The mixture was added to a mixture of 70 g of toluene and 75 g of MMB as a solvent, and dispersed by a bead mill disperser to obtain an ITO dispersion. The particle size of the ITO particles in the ITO dispersion was 49 nm as measured by LB-550 manufactured by Horiba, Ltd. 16.88 g of the obtained ITO dispersion and 0.40 g of polyhydroxy polyolefin polymer (Polytail H manufactured by Mitsubishi Chemical) were mixed with 32.38 g of toluene as a solvent. Finally, 0.011 g of a sulfobetaine-type amphoteric nitrogen-containing fluorine-containing compound represented by the above formula (3) represented by the above formula (3) is added as a film surface conditioner (the content in the coating material is 0.023% by mass), and the mixture is mixed with ITO. A paint for forming a conductive film was prepared. The content of the ITO particles in the paint was 13.5% by mass, and the content of components other than the ITO particles in the solid content of the paint was 10% by mass.

<Comparative Example 1>
A coating for forming an ITO conductive film was prepared without adding and mixing a film surface conditioner. 10.38 g of the ITO dispersion obtained in Example 1, 0.19 g of ethyl cellulose, and 0.45 g of a terpene phenol resin were mixed with 38.78 g of a solvent obtained by mixing MMB and MIBK at a ratio of 1: 2 to form an ITO conductive film. Paint was prepared. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Comparative Example 2>
10.38 g of the ITO dispersion obtained in Example 1, 0.19 g of ethyl cellulose, and 0.44 g of a terpene phenol resin were mixed with 38.78 g of a solvent obtained by mixing MMB and MIBK at a ratio of 1: 2. Finally, 0.013 g (content in the coating material: 0.025% by mass) of a polyester-modified silicone-based tree surface modifier (BYK-313, manufactured by BYK-Chemie) was added and mixed as a film surface modifier. A paint for forming a conductive film was prepared. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Comparative Example 3>
10.38 g of the ITO dispersion obtained in Example 1, 0.18 g of ethyl cellulose, and 0.41 g of a terpene phenol resin were mixed with 38.78 g of a solvent obtained by mixing MMB and MIBK as solvents in a ratio of 1: 2. Finally, 0.050 g (content of 0.100% by mass in the paint) of a polyester-modified silicone-based tree surface modifier (BYK-313, manufactured by BYK-Chemie) was added and mixed as a film surface modifier. A paint for forming a conductive film was prepared. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Comparative Example 4>
A cationic nitrogen-containing fluorine-containing compound represented by the above formula (9) was added and mixed as a film surface conditioner so that the content in the coating material was 0.025% by mass. Except for this, the paint for forming an ITO conductive film was prepared in the same manner as in Example 9.

<Comparative Example 5>
An anionic nitrogen-containing fluorine-containing compound represented by the above formula (8) was added and mixed as a film surface conditioner such that the content in the coating material was 0.025% by mass. Except for this, the paint for forming an ITO conductive film was prepared in the same manner as in Example 9.

<Comparative Example 6>
ITO particles having a BET specific surface area of 70 m ² / g and an L value of 55 are prepared, and 100 g of the ITO particles is added to a mixed solution of 5 g of a polyoxyethylene alkyl ether phosphate ester-based dispersant and 145 g of a solvent MMB. The resulting mixture was dispersed by a bead mill disperser to obtain an ITO dispersion. The particle size of the ITO particles in the ITO dispersion was 150 nm as measured by LB-550 manufactured by Horiba, Ltd. 10.38 g of the obtained ITO dispersion, 0.19 g of ethyl cellulose, and 0.44 g of a terpene phenol resin were mixed with 38.78 g of a solvent obtained by mixing MMB and MIBK at a ratio of 1: 2. Finally, 0.010 g of a sulfobetaine type compound of the amphoteric type nitrogen-containing fluorine compound represented by the above formula (3) (the content in the coating material is 0.020% by mass) is added and mixed as a film surface conditioner, and ITO is mixed. A paint for forming a conductive film was prepared. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Comparative Example 7>
ITO particles having a specific surface area by the BET method of 35 m ² / g and an L value of 36 are prepared, and 100 g of the ITO particles is added to a mixed solution of 5 g of a polyoxyethylene alkyl ether phosphate ester dispersant and 145 g of a solvent MMB. The resulting mixture was dispersed by a bead mill disperser to obtain an ITO dispersion. The particle size of the ITO particles in the ITO dispersion was 70 nm as measured by LB-550 manufactured by Horiba, Ltd. 10.38 g of the obtained ITO dispersion, 0.19 g of ethyl cellulose, and 0.44 g of a terpene phenol resin were mixed with 38.78 g of a solvent obtained by mixing MMB and MIBK at a ratio of 1: 2. Finally, 0.010 g of a sulfobetaine type compound of the amphoteric type nitrogen-containing fluorine-containing compound represented by the above formula (3) (the content in the coating material is 0.020% by mass) is added and mixed as a film surface conditioner, and ITO is mixed. A paint for forming a conductive film was prepared. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Comparative Example 8>
2.50 g of the ITO dispersion obtained in Example 1, 0.13 g of ethyl cellulose, and 0.30 g of a terpene phenol resin were mixed with 47.02 g of a solvent obtained by mixing MMB and MIBK at a ratio of 1: 2. Finally, 0.003 g (the content in the coating material is 0.006% by mass) of a sulfobetaine type compound of the amphoteric type nitrogen-containing fluorine-containing compound represented by the above formula (3) is added and mixed as a film surface modifier, and ITO is mixed. A paint for forming a conductive film was prepared. The content of the ITO particles in this paint was 2.0% by mass, and the content of components other than the ITO particles in the solid content of the paint was 33% by mass.

<Comparative Example 9>
47.00 g of the ITO dispersion obtained in Example 11, 0.32 g of ethyl cellulose, and 0.74 g of a terpene phenol resin were mixed with 0.96 g of a solvent obtained by mixing MMB and MIBK at a ratio of 1: 2. Finally, 0.051 g of a sulfobetaine type compound of the amphoteric type nitrogen-containing fluorine compound represented by the above formula (3) represented by the above formula (3) (the content in the coating material is 0.102% by mass) is added and mixed as a film surface conditioner. A paint for forming a conductive film was prepared. The content of the ITO particles in this paint was 47.0% by mass, and the content of components other than the ITO particles in the solid content of the paint was 8% by mass.

<Comparative Example 10>
10.38 g of the ITO dispersion obtained in Example 1, 0.14 g of ethyl cellulose, and 0.33 g of a terpene phenol resin were mixed with 38.78 g of a solvent obtained by mixing MMB and MIBK at a ratio of 1: 2. Finally, 0.175 g of a sulfobetaine type compound of the amphoteric type nitrogen-containing fluorine compound represented by the above formula (3) as a film surface conditioner (the content in the coating material is 0.350% by mass) was added and mixed, followed by ITO. A paint for forming a conductive film was prepared. The content of the ITO particles in the paint was 8.3% by mass, and the content of components other than the ITO particles in the solid content of the paint was 17% by mass.

<Comparison test and evaluation>
Using a bar coater (manufactured by Yasuda Seiki Seisakusho, model No. 5), the coating material for forming an ITO conductive film obtained in Examples 1 to 14 and Comparative Examples 1 to 10 was 1.1 mm thick, 100 mm long, The film was coated on a 100 mm wide glass substrate and a 0.1 mm thick, 100 mm long, 100 mm wide polyethylene terephthalate (PET) film base material such that the thickness after drying was 0.5 μm. After the application, in Examples other than Examples 11, 12 and 14, and Comparative Examples, 21 types of ITO conductive films were obtained by drying at 80 ° C. for 3 minutes in an air atmosphere. In Example 11, after coating with a bar coater, the coating was dried at 80 ° C. for 3 minutes in an air atmosphere, and irradiated with 240 mJ / cm ² (90 mW / cm ² ) ultraviolet rays to obtain an ITO conductive film. In Examples 12 and 14, an ITO conductive film was obtained by drying at 110 ° C. for 30 minutes in an air atmosphere.

  For the 24 types of ITO conductive films formed on the glass substrate, the contents of the amphoteric nitrogen-containing fluorine-based compound and the ITO particles in the ITO conductive film were measured by the following method. The transparency was evaluated by measuring the total light transmittance and haze, and the conductivity was evaluated by measuring the surface resistivity. About 24 types of ITO conductive films formed on the PET film, the peeling test of the protective film was performed by the following method. Table 1 shows the production conditions and the like of the coating materials for forming the ITO conductive films of Examples 1 to 14 and Comparative Examples 1 to 10, and Table 2 shows the above measurement results and test results. In Table 1, as a type of the film surface conditioner, for example, the one described as “Formula (2)” means “the compound represented by Formula (2)”. In Table 1, EC means ethyl cellulose, and TP means terpene phenol resin.

(1) Content of Amphoteric Nitrogen-Containing Fluorine Compound and ITO Particles in ITO Conductive Film The obtained ITO conductive film was dissolved in acetone to recover the film components. The fluorine concentration in the collected liquid was quantified by ICP emission spectrometry, and the concentration (% by mass) of the amphoteric nitrogen-containing fluorine-based compound was calculated from the compound formula. The film component was recovered by dissolving the obtained ITO conductive film with an acid. The indium concentration in the collected liquid was quantified by ICP emission spectrometry, and the ITO particle concentration (% by mass) was calculated from the compound formula.

(2) Content of Amphoteric Nitrogen-Containing Fluorine Compound and ITO Particles in ITO Conductive Paint The paint was measured, dried, and the solid content after drying was calculated. Further, the obtained solid content was dissolved in acetone, and the fluorine concentration in the dissolved solution was quantified by ICP emission spectrometry. From the compound formula and the solid content concentration, the amphoteric nitrogen-containing fluorine-based compound in the ITO conductive paint was determined. The concentration (% by mass) was calculated. Further, the obtained solid content was dissolved in an acid, and the indium concentration in the dissolved solution was quantified by ICP emission spectrometry. Based on the compound formula and the solid content concentration, the concentration of ITO particles (% by mass) in the ITO conductive paint was determined. Was calculated.

(3) Transparency (total light transmittance and haze)
Using a haze meter (manufactured by Suga Test Instruments, model number HZ-2), the total light transmittance and haze of the ITO conductive film formed on the glass substrate were determined, and the transparency of the ITO conductive film was measured. In addition, the total light transmittance described in Table 1 is a numerical value including the glass base material, the total light transmittance of the glass base material alone was 90.3%, and the haze was also 0.04%. .

(4) Conductivity (surface resistivity)
A film was formed on a glass substrate using a Hiresta (model number: MCP-HT450) manufactured by Mitsubishi Chemical Analytech, and the surface resistivity of the ITO conductive film 2 hours after the film formation was measured at a pressing voltage of 10 V.

(5) Peeling test of protective film A protective film with a silicone-based release agent layer was laminated on the surface of the ITO conductive film formed on the PET film such that the silicone-based release agent layer was opposed to the surface of the ITO conductive film. The upper surface was reciprocated with a hand roller at a speed of 10 mm / s and pressed. Thus, the protective film was uniformly bonded to the surface of the ITO conductive film. After 24 hours, the protective film was gently peeled off the surface of the ITO conductive film. After visually observing the surface of the ITO conductive film after peeling off the protective film, the surface of the ITO conductive film was observed in more detail at a magnification of 50 times with an optical microscope. The case where there was no peeling portion of the ITO conductive film was “good”, and the case where there was partial peeling was “poor”.

  As is clear from Table 2, in Comparative Example 1, since the film surface conditioner was not contained in the coating material at all, the ITO conductive film was peeled off in the peeling test of the protective film, which was "bad".

  Further, in Comparative Example 2, in which 0.025% by mass of the polyester-modified silicone compound was contained in the coating material as a film surface conditioner, the effect of preventing the ITO conductive film from peeling was poor in the peeling test of the protective film, and the film was determined to be “defective”. And the surface resistivity was as high as 15.0 MΩ / □.

  Similarly, in Comparative Example 3, in which the polyester-modified silicone-based compound was contained in the paint at 0.100% by mass, the effect of preventing the ITO conductive film from peeling was exhibited, and the result was determined to be “good”, but the surface resistivity was 85.0 MΩ / □. It was extremely high.

  In Comparative Example 4, in which the coating composition contained 0.025% by mass of the cationic nitrogen-containing fluorine-containing compound as a film surface conditioner, the ITO particles aggregated with the fluorine compound, and the peeling test of the protective film prevented the ITO conductive film from peeling. In addition to being poor and judged to be "poor", the total light transmittance was as low as 85.5% and the haze was as high as 4.0%.

  Also, in Comparative Example 5 in which 0.025% by mass of an anionic nitrogen-containing fluorine-based compound was contained in the paint as a film surface conditioner, the ITO particles aggregated with the fluorine compound, and the peeling test of the protective film prevented the ITO conductive film from peeling. In addition to the poor effect, it was determined to be "bad", and the surface resistivity was as high as 10.0 MΩ / □, the total light transmittance was as low as 86.6%, and the haze was as high as 3.5%.

Comparative Example 6 using ITO particles having a specific surface area of 70 m ² / g and an L value of 40 has a high surface resistivity of 12.0 MΩ / □, a low total light transmittance of 85.3%, and a haze of 10. It was as high as 5%.

In Comparative Example 7 using ITO particles having a specific surface area of 35 m ² / g and an L value of 36, the total light transmittance was as low as 86.3% and the haze was as high as 2.3%.

  Comparative Example 8, in which the ITO content in the film was 68.0% by mass and the ITO content in the paint was 2.0% by mass, was poor in peeling prevention effect because it was a thin film, and was determined to be "poor." In addition, the surface resistivity was as high as 5.3 MΩ / □.

  Comparative example in which the content of the ITO particles in the paint is 47.0% by mass, the component other than the ITO particles in the solid content of the paint is 8% by mass, and the content of the ITO particles in the film is 92% by mass. No. 9 lacked the resin component and thus was judged to be "defective" because of a poor peel prevention effect. In addition, the total light transmittance was as low as 86.8% and the haze was as high as 2.9%. .

  Comparative Example 10 containing 3.50% by mass of the amphoteric nitrogen-containing fluorine-based compound in the coating film had a high surface resistivity of 3.5 MΩ / □ and a high haze of 2.5%.

  On the other hand, the ITO conductive films obtained in Examples 1 to 14 which were formed with a paint containing an amphoteric nitrogen-containing fluorine-based compound as a film surface conditioner were all “good” in the peeling test of the protective film. The surface resistivity was as low as 3.0 MΩ / □ or less, the total light transmittance was as high as 87.8% or more, and the haze was as low as 2.0% or less.

  The ITO conductive film of the present invention is used as an ITO conductive film in the field of peeling the film after laminating a protective film or a cover film on the conductive film surface.

Claims (2)

In an ITO conductive film in which ITO particles are uniformly dispersed in a binder resin,
The ITO conductive film of 100% by mass contains 70 to 90% by mass of the ITO particles and 3% by mass or less of an amphoteric nitrogen-containing fluorine-based compound represented by the following formula (1) as a film surface conditioner. An ITO conductive film, wherein the particles have a specific surface area by a BET method of 40 to 65 m ² / g and an L value of 37 or less.

However, in the formula (1), Rf ¹ and Rf ² are the same or different, each having 1 to 6 carbon atoms and being a linear or branched perfluoroalkyl group. Rf ³ is a linear or branched perfluoroalkylene group having 1 to 6 carbon atoms. R is a linking group that is a divalent organic group, and X is an amphoteric type hydrophilicity-imparting group. In an ITO conductive film forming paint containing ITO particles, a binder resin and a solvent,
100% by mass of the coating material contains 3 to 45% by mass of the ITO particles, and 0.3% by mass or less of a nitrogen-containing fluorine-containing compound represented by the following formula (1) as a film surface conditioner. In the solid content of 100% by mass, a component other than the ITO particles is contained in an amount of 10 to 30% by mass, and the ITO particles have a specific surface area according to a BET method of 40 to 65 m ² / g and an L value of 37 or less. Paint for forming an ITO conductive film.

However, in the formula (1), Rf ¹ and Rf ² are the same or different, each having 1 to 6 carbon atoms and being a linear or branched perfluoroalkyl group. Rf ³ is a linear or branched perfluoroalkylene group having 1 to 6 carbon atoms. R is a linking group that is a divalent organic group, and X is an amphoteric type hydrophilicity-imparting group.