JP2016194031A - Composition for ito conductive film formation and ito conductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for forming an ITO conductive film which can suppress the increase of surface resistivity of an ITO conductive film under high temperature and high humidity and irradiation with ultraviolet rays, is excellent in adhesiveness to a substrate, and has good conductivity, transparency and light resistance, and to provide an ITO conductive film.SOLUTION: There is provided a composition which contains ITO particles, a binder resin and an organic solvent, contains 3-45 mass% of the ITO particles in the composition, and 10-52 mass% of the components other than the ITO particles in a solid matter of the composition, where the ITO particles have a specific surface area of 42-65 m/g by a BET method and an L value of 36 or less, and the binder resin contains ethyl cellulose and a terpene phenol resin having a softening point of 130-160°C. The ITO conductive film is formed by uniformly dispersing ITO particles having the above described predetermined specific surface area by the BET method and the above described predetermined L value into a terpene phenol resin having the above described softening point, and contains 48-90 mass% of the ITO particles in the film and 10-52 mass% of the components other than the ITO particles in the film.SELECTED DRAWING: None

Description

  The present invention is capable of suppressing changes in the surface resistivity of an ITO conductive film under high temperature and high humidity and under ultraviolet irradiation, has excellent adhesion to a substrate, and has both good conductivity, transparency and light resistance. The present invention relates to a composition for forming a film and an ITO conductive film. In this specification, ITO refers to indium tin oxide.

  Transparent electrodes are used in display devices such as LCD (Liquid Crystal Display), PDP (Plasma Display Panel), organic EL (ElectroLuminescence), and touch panels. This transparent electrode is often composed of a transparent conductive material made of ITO or the like. Such a transparent electrode is usually formed into a film by a sputtering method or the like (see, for example, Patent Document 1). However, with an increase in the size of the substrate on which the film is formed, there is a problem that the sputtering apparatus becomes large and the cost increases. In order to solve this problem, a method of applying a transparent conductive film forming coating solution or a transparent conductive paste composition on a substrate instead of the sputtering method has been proposed (for example, see Patent Documents 2 and 3).

  Patent Document 2 discloses a coating liquid for forming a transparent conductive film suitable for forming an ITO transparent conductive film having both transparency and conductivity by a coating method, particularly an ink jet printing method. This coating liquid for forming a transparent conductive film contains acetylacetone indium, organotin compound, cellulose derivative, alkylphenol and / or alkenylphenol, dibasic acid ester and / or benzyl acetate, and diethylene glycol derivative. The total content is 1 to 30% by weight, and the content of the cellulose derivative is 5% by weight or less.

  Patent Document 3 discloses a transparent conductive paste composition that can form a transparent conductive film having good surface properties and good conductivity and transparency when applied on a substrate by printing. . This transparent conductive paste composition contains 80 to 99% by weight of transparent conductive particles, a binder resin, a terpene solvent, and an organic solvent such as a ketone solvent in the solid content of the composition.

  However, like the transparent conductive film forming coating solution of Patent Document 2, if the cellulose derivative alone is used as the binder, for example, when the transparent conductive film forming coating solution is formed on the PET film of the substrate, the film is based on It was easy to peel off from the material, which was one of the causes of reducing reliability. Moreover, when the transparent conductive film applied by the methods of Patent Documents 2 and 3 described above is placed under high temperature and high humidity for a long time, the surface resistivity tends to increase due to oxygen and moisture in the atmosphere. In order to solve this problem, a transparent conductive material having a small change in surface resistivity due to the influence of temperature and humidity is disclosed by containing transparent conductive particles such as resin, ITO powder, silica material, and a silane coupling agent. (For example, see Patent Document 4). The transparent conductive film formed of the transparent conductive material disclosed in Patent Document 4 can sufficiently suppress an increase in surface resistivity even under high temperature and high humidity.

JP 2004-315951 A (paragraph [0002]) JP 2006-28431 A (summary, claim 1, claim 7) JP2011-192401A (summary, claim 1) JP 2009-135044 (Abstract, Claim 1) WO 2006/028131 (Claim 12, Paragraph [0010], Paragraph [0012], Paragraph [0022], Paragraph [0025], Paragraphs [0041] to [0046], FIGS. 1, 4, and 8)

  However, in recent years, the use of transparent conductive films has become more diverse, and for conductive film formation that can suppress changes in the surface resistivity of transparent conductive films under high temperature and high humidity even under severer conditions than before. There is a need for a composition.

  Furthermore, in recent years, the number of cases in which a touch panel is used in a harsh environment exposed to direct sunlight for a long time is increasing. In this case, the touch panel may be deteriorated by the influence of ultraviolet rays or the like included in the sunlight. Specifically, when an ITO conductive film is used for the transparent electrode of the touch panel, the surface resistivity of the ITO conductive film is lowered, causing a problem in the sensitivity of the touch sensor. In order to solve this problem, there has been disclosed a light-resistant resistive touch panel capable of preventing deterioration due to ultraviolet rays and exhibiting excellent performance even in relatively severe outdoor use (for example, patents) Reference 5). This resistive film type touch panel is configured by laminating a polarizing plate, an upper planar member, an ITO transparent conductive film, a wiring board, a spacer, an ITO transparent conductive film, and a lower planar member, and an ultraviolet absorbing material as the upper planar member. An ultraviolet-absorbing pressure-sensitive adhesive layer containing is interposed between two siloxane cross-linked acrylic silicone resin film layers. According to this touch panel, even if ultraviolet rays are incident on the touch panel by the ultraviolet absorbing adhesive layer, deterioration due to ultraviolet rays is prevented. However, in this touch panel, it is necessary to provide an ultraviolet-absorbing adhesive layer separately, which increases the number of constituent elements and complicates the manufacturing process.

  The first object of the present invention is to suppress the increase in surface resistivity of ITO conductive film under high temperature and high humidity even under severer conditions than before, excellent in adhesion to the substrate and good An object of the present invention is to provide a composition and an ITO conductive film for forming an ITO conductive film having both conductivity and transparency.

  The second object of the present invention is to suppress the decrease in the surface resistivity of the ITO conductive film without requiring a special UV-absorbing adhesive layer, even in a harsh environment where ultraviolet rays are irradiated for a long time. It is providing the composition and ITO electrically conductive film for forming the ITO electrically conductive film which is excellent in adhesiveness, was excellent in the adhesiveness to a base material, and had favorable electroconductivity and transparency.

According to a first aspect of the present invention, in the composition for forming an ITO conductive film comprising ITO particles, a binder resin, and an organic solvent, 3 to 45% by mass of the ITO particles are contained in 100% by mass of the composition. In a solid content of 100% by mass, the composition contains 10 to 52% by mass of components other than the ITO particles, and the ITO particles have a specific surface area by the BET method of 42 to 65 m ² / g and an L value of 36 or less, The binder resin includes ethyl cellulose and a terpene phenol resin having a softening point of 130 to 160 ° C.

  2nd viewpoint of this invention is invention based on 1st viewpoint, Comprising: The ITO electrically conductive film formation whose mass ratio of the said ethyl cellulose and the said terpene phenol resin is ethyl cellulose: terpene phenol resin = 10-80: 90-20 Composition.

  A third aspect of the present invention is an invention based on the first or second aspect, wherein the composition for forming an ITO conductive film further comprises 1 to 15 parts by mass of a dispersant with respect to 100 parts by mass of the liquid ITO particles. It is.

  A fourth aspect of the present invention is an invention based on any one of the first to third aspects, and is an ITO conductive film forming composition used for a screen printing paste or paint.

  A fifth aspect of the present invention is the invention based on the fourth aspect, and when used in the screen printing paste, the organic solvent is 3-methoxy-3-methyl-1-butanol and butyl carbitol. An ITO conductive film forming composition comprising an acetate or α-terpineol solvent.

  6th viewpoint of this invention is invention based on 4th viewpoint, Comprising: When used for the said coating material, when the said organic solvent is 3-methoxy-3-methyl- 1-butanol, 2-butanone, 4- One selected from the group consisting of methyl-2-pentanone, ethanol, 2-propanol, 1-butanol, toluene, methanol, 1-propanol, ethyl acetate, butyl acetate, acetone, 2,4-pentanedione and xylene, or An ITO conductive film forming composition comprising two or more kinds of solvents.

  A seventh aspect of the present invention is an invention based on any one of the first to sixth aspects, wherein the phenolic antioxidant or the hindered amine light stabilizer is added in 100% by mass of the solid content of the composition. It is a composition for ITO electrically conductive film formation which further contains 1-5 mass%.

  An eighth aspect of the present invention is the invention based on any one of the first to seventh aspects, further comprising an organic silicon compound having a hydrolyzing group and water in the components other than the ITO particles, The content of the silicon compound is 5 to 52% by mass in 100% by mass of the solid content of the composition, and the water content is a methoxy group or a hydrolyzable group contained in the organosilicon compound having the hydrolyzable group. It is an ethoxy group, and is a composition for forming an ITO conductive film that is 0.05 to 0.7 times the number of moles of this hydrolyzable group.

A ninth aspect of the present invention is an invention based on any one of the first to seventh aspects, wherein ITO particles are coated with a hydrolyzate of organic silicon, and the ITO is coated with the hydrolyzate of organic silicon. ITO conductive material having a specific surface area of 50 to 70 m ² / g of particles by BET method and a coating amount of the hydrolyzate of organosilicon of 0.5 to 15 parts by mass with respect to 100 parts by mass of ITO particles before coating It is a composition for film formation.

According to a tenth aspect of the present invention, ITO particles having a specific surface area of 42 to 65 m ² / g BET method and an L value of 36 or less are uniformly dispersed in a terpene phenol resin having a softening point of 130 to 160 ° C. It is an ITO conductive film containing 48 to 90% by mass of the ITO particles and 10 to 52% by mass of components other than the ITO particles in the film.

  An eleventh aspect of the present invention is an invention based on the tenth aspect, wherein the phenolic antioxidant or the hindered amine light stabilizer is added in an amount of 0.1 to 5% by mass in 100% by mass of the solid content of the composition. % Further ITO conductive film.

A twelfth aspect of the present invention is the invention based on the tenth aspect, further comprising an organosilicon compound having a hydrolyzable group and water in components other than the ITO particles, and the content of the organosilicon compound Is 5 to 52% by mass in 100% by mass of the solid content of the composition, and the water content is
The ITO conductive film in which the hydrolyzable group contained in the organosilicon compound having the hydrolyzable group is a methoxy group or an ethoxy group, and the number of moles of the hydrolyzable group is 0.05 to 0.7 times. It is.

A thirteenth aspect of the present invention is a terpene phenol resin in which ITO particles coated with a hydrolyzate of organosilicon having a specific surface area by the BET method of 50 to 70 m ² / g have a softening point of 130 to 160 ° C. In the film, 70 to 90% by mass of ITO particles coated with the organosilicon hydrolyzate and 10 to 10 components other than the ITO particles coated with the organosilicon hydrolyzate are contained in the film. An ITO conductive film containing 30% by mass and having a coating amount of the hydrolyzate of organosilicon of 0.5 to 15 parts by mass with respect to 100 parts by mass of the ITO particles before coating.

  14th viewpoint of this invention is invention based on 13th viewpoint, Comprising: In components other than the ITO particle | grains coat | covered with the hydrolyzate of the said organosilicon, a phenolic antioxidant or a hindered amine light stabilizer is added. Furthermore, it is an ITO conductive film.

  In the composition for forming an ITO conductive film according to the first aspect of the present invention, it contains 3-45 mass% of ITO particles having a predetermined specific surface area and an L value. It can have transparency. In addition, by including a terpene phenol resin having a high softening point of 130 to 160 ° C. as the binder resin, when this composition is applied onto the substrate, the ITO conductive film has excellent adhesion to the substrate, and ITO A change in surface resistivity of the conductive film under high temperature and high humidity is suppressed. Moreover, when ethyl cellulose is contained, when this composition is used as a printing paste, the printability can be improved.

  In the composition for forming an ITO conductive film according to the second aspect of the present invention, in the range of a predetermined mass ratio, when ethyl cellulose has a smaller mass ratio than the terpene phenol resin, the adhesion effect of the terpene phenol resin is obtained. Since it is easy to express, it has the effect of increasing the adhesion to the substrate, and conversely, when ethyl cellulose has a larger mass ratio than terpene phenol resin, it can increase the viscosity of the liquid composition with ethyl cellulose. It becomes easy and has the effect of improving the printability as a screen printing paste.

  In the composition for forming an ITO conductive film according to the third aspect of the present invention, by including a predetermined amount of the dispersant, the effect of improving the optical properties of the film when formed into a coating film, that is, the transparency is improved, and the haze is improved. Has the effect of reducing.

  The composition for forming an ITO conductive film according to the fourth aspect of the present invention has an advantage of being used for a screen printing paste or paint.

  When used in the screen printing paste of the fifth aspect of the present invention, when 3-methoxy-3-methyl-1-butanol is used as the organic solvent, it is water-soluble while having a relatively high boiling point (174 ° C.). Therefore, the ITO particles can be easily dispersed, and the optical properties of the coating film can be improved. In addition, when butyl carbitol acetate (247 ° C.) or α-terpineol (219 ° C.), which is a high boiling point solvent, is used in combination, the problem of quick drying at the time of screen printing in the case of using 3-methoxy-3-methyl-1-butanol alone is caused. Thus, variation in the surface resistivity of the film can be suppressed even in continuous production.

  When used in the paint according to the sixth aspect of the present invention, when 3-methoxy-3-methyl-1-butanol is used as the organic solvent, it is water-soluble while having a relatively high boiling point (174 ° C.). It is possible to easily disperse ITO particles and improve the optical properties of the coating film. Low-boiling solvents such as 2-butanone, 4-methyl-2-pentanone, ethanol, 2-propanol, 1-butanol, toluene, methanol, 1-propanol, ethyl acetate, butyl acetate, acetone, 2,4-pentanedione In addition, when one or more solvents selected from the group consisting of xylene and xylene are used in combination, the drying property can be improved more than when 3-methoxy-3-methyl-1-butanol is used alone.

  In the composition for forming an ITO conductive film according to the seventh aspect of the present invention, the surface resistance of the ITO conductive film made from this composition at a high temperature by further containing a phenol-based antioxidant or a hindered amine light stabilizer. The rate change can be further suppressed.

  In the composition for forming an ITO conductive film according to the eighth aspect of the present invention, by further including an organosilicon compound having a hydrolyzable group and water, the hydrolyzable group reacts with water when the composition is heated. Some silanol groups are generated. Since the organosilicon compound in which this silanol group is partially generated has a bonding force between the silanol group and ITO, the ITO conductive film made from this composition is further suppressed from changing the surface resistivity under high temperature and high humidity. The

  In the composition for forming an ITO conductive film according to the ninth aspect of the present invention, since ITO particles having a predetermined specific surface area are coated with a predetermined amount of a hydrolyzate layer of organosilicon, when the ITO conductive film is formed, Radicals generated from the ITO particles when irradiated with ultraviolet rays are suppressed by the hydrolyzate coating layer as long as the conductivity inherent in the ITO particles is not impaired.

  In the ITO conductive film according to the tenth aspect of the present invention, ITO particles having a predetermined specific surface area and L value are uniformly dispersed in a terpene phenol resin having a high softening point, and other than predetermined amounts of ITO particles and ITO particles. By including a component, the change of the surface resistivity under high temperature and high humidity of an ITO electrically conductive film can be suppressed, it is excellent in the adhesiveness to a base material, and can have favorable electroconductivity and transparency.

  The ITO conductive film according to the eleventh aspect and the fourteenth aspect of the present invention further suppresses a change in surface resistivity at high temperatures of the ITO conductive film by further including a phenolic antioxidant or a hindered amine light stabilizer. can do.

  In the ITO conductive film according to the twelfth aspect of the present invention, it is possible to further suppress the change in surface resistivity of the ITO conductive film at high temperature and high temperature by further containing an organosilicon compound having a hydrolyzable group and water. .

  In the ITO conductive film of the thirteenth aspect of the present invention, ITO particles having a predetermined specific surface area are coated with a predetermined amount of hydrolyzate of organosilicon, and uniformly dispersed in a terpene phenol resin having a high softening point, and By including a predetermined amount of ITO particles and components other than ITO particles, when ultraviolet light is incident on the ITO conductive film, it is possible to suppress a decrease in surface resistivity and excellent light resistance, and excellent adhesion to a substrate, It can have both good conductivity and transparency.

  Next, the 1st form for implementing this invention is demonstrated.

[ITO particles in the first form]
The ITO particles according to the first embodiment of the present invention have a specific surface area according to the BET method of 42 to 65 m ² / g and an L value of 36 or less. When the specific surface area according to the BET method is less than 42 m ² / g, the haze is increased when the ITO conductive film having a desired surface resistivity is formed, and the transparency of the film is lowered. If the content of the ITO particles of the first form in the film is decreased in order to reduce the haze, the desired surface resistivity of the film cannot be obtained and the conductivity of the film is deteriorated. Originally, if 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 dispersant is used. When the ITO particles of the first form are mixed with the resin in such an added amount, there is a problem that the dispersion of the ITO particles into the resin becomes insufficient and the haze of the coating film becomes worse. In order to reduce haze so as not to cause this problem, when the ITO particles of the first form exceeding 65 m ² / g are used, it is necessary to increase the amount of the dispersant for dispersing the ITO particles in the resin. Arise. Increasing the dispersant causes problems such as poor film conductivity and poor adhesion to the substrate. For this reason, the upper limit of the specific surface area by the BET method of the ITO particles of the first form is determined to be 65 m ² / g. Further, when the content of the ITO particles in the film is increased in order to obtain a desired surface resistivity, the base of the ITO conductive film is formed when the ITO conductive film forming composition of the first form is applied on the substrate. Adhesion to the material is poor. On the other hand, when the L value of the ITO particles of the first form exceeds 36, the ITO is not sufficiently reduced, so that the surface resistivity of the film is increased and the conductivity of the film is deteriorated. In addition, since the particles become large, the haze of the film increases and the transparency of the film decreases.

[Method for Producing ITO Particles of First Form]
The first form of ITO particles is a method of producing indium tin oxide particles by firing coprecipitated hydroxides of indium and tin. It is obtained by precipitating and baking it.

Specifically, the ITO particles of the first form are manufactured by the following method. First, a tin salt and an indium salt are weighed and mixed at a predetermined ratio, the mixture is dissolved in pure water to obtain a mixed solution of a tin salt and an indium salt, and the mixed solution and an alkali are reacted. Indium and tin in the solution are precipitated in the presence of alkali to form a coprecipitated hydroxide of indium and tin. Examples of the tin and indium salts include hydrochloride, sulfate, and nitrate. For example, a divalent tin compound (SnCl ₂ .2H ₂ O or the like) is used as a tin salt, and indium trichloride (InCl ₃ ) is used as an indium salt, and the pH of the solution is 4.0 to 9.3, preferably pH 6.0. -8.0, and liquid temperature is adjusted to 5 degreeC or more, Preferably liquid temperature is 10 to 80 degreeC. Thereby, the co-precipitated hydroxide of indium tin having a dry powder having a color tone of a bright yellow color to an amber color can be precipitated. The hydroxide having a yellowish to dark blue color tone is superior in crystallinity to the conventional white indium tin hydroxide.

It notes that a tetravalent tin compound (such as SnCl _4), becomes a white precipitate, not a precipitate having a color tone of Kakiiro from bright yellow. Further, when the pH of the solution is lower than 4.0 (acidic side) or higher than 9.3 (alkaline side), a pale yellowish white precipitate is formed, and a precipitate having a yellowish to dark blue color tone is not formed. The white precipitation due to the tetravalent tin compound and the above pale yellowish white precipitation are both lower in crystallinity than the precipitation having a yellowish to amber color tone, and even if these precipitates are fired, the crystallinity as in the present invention High ITO particles cannot be obtained. Further, if the pH during the reaction is less than 4, the L value will exceed 36 even when the temperature during firing of indium tin hydroxide described later is 600 ° C.

In order to adjust the liquid property during the reaction to pH 4.0 to 9.3, for example, a mixed aqueous solution of indium trichloride (InCl ₃ ) and tin dichloride (SnCl ₂ .2H ₂ O) is used. The aqueous alkaline solution may be simultaneously dropped into water to adjust the pH range. As the alkaline aqueous solution, ammonia water [NH ₃ water], ammonium hydrogen carbonate water [NH ₄ HCO ₃ water] or the like may be used.

  After the coprecipitated indium tin hydroxide is formed, the coprecipitate is washed with pure water, and washed until the electrical conductivity of the supernatant is 200 μS / cm or less, preferably 20 μS / cm or less (hereinafter referred to as a gradient). The coprecipitate is recovered by solid-liquid separation after washing. When the electrical conductivity of the supernatant is higher than 200 μS / cm, impurities such as chlorine are not sufficiently removed, and high-purity indium tin oxide particles cannot be obtained.

In the first embodiment, the indium tin hydroxide can be produced by the following three methods.
(a-1) In the first method, first, solid-liquid separated indium tin hydroxide is dried at 100 to 120 ° C. overnight under a nitrogen gas atmosphere, and then 270 to 800 ° C., 30 minutes to 6 Bake in time. Next, the oxide obtained by firing is impregnated in an alcohol surface treatment solution, and then subjected to a surface modification treatment by heating at 150 to 600 ° C. in a nitrogen gas atmosphere.
(b-1) In the second method, first, solid-liquid separated indium tin hydroxide is impregnated with an alcohol surface treatment solution. Next, the indium tin hydroxide impregnated with the surface treatment liquid is heated at 270 to 600 ° C. in a nitrogen gas atmosphere, and dried and fired continuously to perform the surface modification treatment once.
(c-1) In the third method, first, solid-liquid-separated indium tin hydroxide is dried at 100 to 120 ° C. overnight in an air atmosphere, and then 270 to 650 ° C., 30 minutes to 6 hours. Bake with. Next, the oxide obtained by firing is impregnated in an alcohol surface treatment solution, and then subjected to a surface modification treatment by heating at 150 to 600 ° C. in a nitrogen gas atmosphere.
In the first and second methods, the heat treatment is performed in a nitrogen gas atmosphere even after the surface treatment liquid of alcohol is impregnated with a material fired in a high-temperature air atmosphere and then treated in a nitrogen gas atmosphere. This is because the reduction is difficult to proceed, and in the Lab color system, ITO particles exceeding the L value 36 are obtained. Therefore, in the third method, the atmospheric firing temperature is set to 650 ° C. or lower.

Aggregates obtained by the above three methods are all crushed and loosened to become indium tin oxide. In other words, indium tin hydroxide becomes surface-modified indium tin oxide particles (ITO particles) by the above treatment. The ITO particles of the first form thus obtained have a specific surface area by the BET method of 42 to 65 m ² / g and a dark blue color with an L value of 36 or less, a <0, b <0 in the Lab color system. Have a different color tone. Since the ITO particles are fine and have high crystallinity, when mixed with a resin to form a film or sheet, the ITO particles have high transparency and excellent conductivity.

In the said 1st and 2nd manufacturing method, if a calcination temperature is less than 270 degreeC, it will remain a hydroxide and will not become an oxide. On the other hand, when the firing temperature exceeds 800 ° C., the ITO particles are sintered with each other, so that the specific surface area becomes less than 42 m ² / g.

In the first or third production method, only firing is performed and no reduction treatment with alcohol is performed. Even if firing at 600 ° C., the specific surface area of the ITO particles by the BET method is 65 m ² / g or less, The L value exceeds 36.

[Method for Producing Composition for Forming ITO Conductive Film of First Form]
The first form of ITO particles obtained by the above method is mixed with a binder resin and an organic solvent to prepare an ITO conductive film forming composition of the first form. At this time, a dispersant may be mixed. By mixing the dispersant, the transparency when formed into a coating film is further improved. This composition contains 3 to 45% by weight, preferably 4 to 40% by weight, of the first form of ITO particles in 100% by weight of the composition, and in the solid content of 100% by weight of the first form. It is prepared so that it may contain 10-52 mass%, preferably 15-35 mass% of components other than ITO particles. When the content of the ITO particles of the first form obtained by the above method is less than 3% by mass, the conductivity of the ITO conductive film of the first form made from this composition does not increase. On the other hand, if it exceeds 45% by mass, the composition becomes thicker and the stability with time deteriorates, the binder resin is relatively insufficient, and the adhesion between the particles of the ITO particles of the first form is reduced. The surface resistivity of the ITO conductive film of 1 form deteriorates. In addition, if the component other than the ITO particles of the first form is less than 10% by mass, the increase of the surface resistivity of the ITO conductive film of the first form under high temperature and high humidity cannot be suppressed, and the adhesion to the substrate is sufficient. I can't get it. On the other hand, if it exceeds 52% by mass, the stability with time deteriorates, for example, the composition thickens, and the surface resistivity of the ITO conductive film of the first form deteriorates, making it difficult to obtain conductivity.

  As binder resin of the 1st form which is solid content of this composition, terpene phenol resin which has ethyl cellulose and a 130-160 degreeC softening point is included. When the softening point of the terpene phenol resin is lower than 130 ° C., it becomes difficult to suppress the change in surface resistivity when the use condition of the ITO conductive film of the first embodiment is a high temperature of 60 ° C. or higher. Also, terpene phenol resins exceeding 160 ° C. are difficult to obtain. The mass ratio of ethyl cellulose to terpene phenol resin is preferably ethyl cellulose: terpene phenol resin = 10-80: 90-20, and more preferably 20-50: 80-50. When the mass ratio of ethyl cellulose is less than 10 and the mass ratio of terpene phenol resin exceeds 90, it is difficult to increase the viscosity of the paste during screen printing, and there is a problem that the screen printability is deteriorated. Is more than 80 and the mass ratio of the terpene phenol resin is less than 20, there is a problem that the adhesion of the ITO conductive film of the first embodiment to the substrate is lowered. The terpene phenol resin is Sylvalite TP7042 (softening point: 145 ° C.) manufactured by Arizona Chemical Co., Ltd. Tamanoru 803L (softening point: 140-160 ° C.) manufactured by Arakawa Chemical Industries, 901 (softening point: 120-135 ° C.), YS manufactured by Yasuhara Chemical Co., Ltd. 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.

  It is preferable that 1-10 mass parts of the dispersing agent of the 1st form contained in the composition for ITO electrically conductive film formation of a 1st form is contained with respect to 100 mass parts of ITO particles of a 1st form. As an example of the dispersant in the first form, any pigment dispersant can be used as long as it can stably disperse the pigment in fine particles. Specifically, polyoxyethylene styrenated phenyl ether ammonium sulfate, polyoxyalkylene decyl ether sodium sulfate, polyoxyethylene tridecyl ether sodium sulfate, polyoxyethylene isodecyl ether ammonium sulfate, polyoxyethylene lauryl ether sodium 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 esters, alkyl benzene sulfonates, alkyl phthalene sulfonic acids Salt, polyoxyethylene alkyl ether phosphate, polyoxy Alkyl phosphoric acid such as ethylene alkyl ether phosphate, polyoxyethylene lauryl ether phosphate, polyoxyethylene alkyl ether phosphate, polyoxyethylene tridecyl ether phosphate, polyoxyethylene styrenated phenyl ether phosphate Ester salt, polyoxyethylene alkyl ether acetate, alkyl ether acetate such as sodium polyoxyethylene lauryl ether acetate, disodium lauryl sulfosuccinate polyoxyethylene alkyl sulfosuccinate disodium, polyoxyethylene sulfosuccinate disodium lauryl, 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 ITO conductive film forming composition of the first form becomes insufficient, and the transparency of the coating film tends to be insufficient. Moreover, when it exceeds 10 mass parts, it will have a bad influence on the electroconductivity of the ITO electrically conductive film of a 1st form, and the adhesiveness of a coating film.

  As the organic solvent of the first form contained in the ITO conductive film forming composition of the first form, 3-methoxy-3-methyl-1-butanol is used as the organic solvent. Since 3-methoxy-3-methyl-1-butanol has a relatively high boiling point and is water-soluble, it is easy to disperse the ITO particles of the first form and improve the optical properties of the coating film. It is possible to plan. However, when the composition for forming an ITO conductive film according to the first embodiment is a paste for screen printing, if 3-methoxy-3-methyl-1-butanol is used alone, the drying speed is high, so that many films are formed. Then, since the uniformity of the surface resistivity of the film becomes difficult, a high boiling point solvent butyl carbitol acetate or α-terpineol is used in combination. When the composition for forming an ITO conductive film according to the first embodiment is a paint, quick drying is required, so that 2-butanone, 4-methyl-2-pentanone, ethanol, 2-propanol, and 1-butanol have low boiling points. , Toluene, methanol, 1-propanol, ethyl acetate, butyl acetate, acetone, 2,4-pentanedione, xylene and the like and 3-methoxy-3-methyl-1-butanol are used in combination.

  The addition amount of the organic solvent is preferably 50 to 95% by mass in 100% by mass of the composition. When the amount of the organic solvent added is large, the composition becomes a coating composition, and when it is small, the composition becomes a paste composition.

  It is preferable that the composition for forming an ITO conductive film according to the first embodiment further includes a phenolic antioxidant or a hindered amine light stabilizer. Examples of the phenolic antioxidant include ADEKA, product names AO-20, AO-30, AO-40, AO-60, AO-80 and the like. Examples of the hindered amine light stabilizer include ADEKA, product names LA-52, LA-57, LA-63, and LA-72. By further including a phenolic antioxidant or a hindered amine light stabilizer, it is possible to further suppress the change in surface resistivity of the ITO conductive film made from this composition at a high temperature. For this reason, it is preferable that the addition amount of a phenolic antioxidant or a hindered amine light stabilizer is 0.1-5 mass% in 100 mass% of solid content of a composition.

  More preferably, the composition for forming an ITO conductive film of the first embodiment further includes an organosilicon compound having a hydrolyzable group and water. When an organosilicon compound having a hydrolyzable group is added alone, the surface resistivity change after a predetermined time has elapsed under high temperature and high humidity, but by adding water, The change in the surface resistivity after elapse of a predetermined time can be suppressed, and the adhesion with the substrate can be further improved. As the organosilicon compound having a hydrolyzable group, vinyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., product name KBM-1003), 3-glycidoxypropyltrimethoxylane (Shin-Etsu Chemical Co., Ltd., product name KBM-403), 3-methacryloxypropylmethyldimethoxysilane (Shin-Etsu Chemical Co., Ltd., product name KBM-503), 3-mercaptopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., product name KBM-803), methyltriethoxysilane (Shin-Etsu Chemical Co., Ltd.) And product name KBE-13). Moreover, the silane compound (Mitsubishi Materials Electronics Chemicals, product name SB-10A) etc. which added water to the organosilicon compound which has a hydrolysis group beforehand, and hydrolyzed the organosilicon compound is mentioned.

  By further including an organosilicon compound having a hydrolyzable group and water in the components other than the ITO particles, further suppressing the change in surface resistivity of the ITO conductive film made from this composition under high temperature and high humidity. Can do. For this reason, it is preferable that the addition amount of the organosilicon compound which has a hydrolysis group is 5-52 mass% in 100 mass of solid content of a composition. The amount of water added is such that the hydrolyzable group contained in the organosilicon compound having a hydrolyzable group is, for example, a methoxy group or an ethoxy group, and 0.05 to 0.7 times the mol of the hydrolyzable group. It is preferably a number. If it is less than 0.05 times the number of moles, hydrolysis is insufficient and it becomes difficult to suppress the temporal change in surface resistivity. On the other hand, when the number of moles exceeds 0.7 times, the surface resistivity when formed into a film increases and haze tends to increase. In addition, when an organic solvent that is incompatible with water is selected because water is added, the haze increases, and thus a solvent compatible with water such as 3-methoxy-3-methyl-1-butanol. If h is used, haze increase can be reduced.

  The preparation procedure of the composition for forming an ITO conductive film of the first form is as follows. First, when the ITO particles of the first form are added to an organic solvent and a dispersant is used, the first is added to the organic solvent in which the dispersant is dissolved. The ITO particles in the form 1 are added, and the ITO particles are dispersed using a wet bead mill or the like until the dispersed particle size of the ITO particles reaches a desired particle size, thereby producing an ITO dispersion. Although a dispersion | distribution density | concentration is not limited, it is 10-75 mass% as ITO. If it is less than 10% by mass, the productivity is poor, and it becomes impossible to produce a high-concentration paste when a resin solution or the like is mixed at the time of producing a paste in a subsequent process. Moreover, when it exceeds 75 mass%, it will become difficult to disperse | distribute ITO particle | grains and productivity will worsen. Meanwhile, the binder resin is the same as the organic solvent in which the ITO particles are dispersed or mixed in another organic solvent, and the binder resin is dissolved by heating the organic solvent at a temperature of 40 to 80 ° C. Prepare a resin solution. Finally, this resin solution, ITO dispersion liquid, phenolic antioxidant, hindered amine light stabilizer or organosilicon compound having a hydrolyzing group and an additive such as water are mixed, and this mixture is mixed with a revolving mixer. By stirring, kneading, and dispersing in a state of being heated at a temperature of 40 to 80 ° C. with an apparatus such as a roll, a planetary mixer, a ball mill, a homogenizer, an ultrasonic dispersing machine, a three roll, a Henschel mixer, etc. An ITO conductive film forming composition is obtained.

  Next, a second mode for carrying out the present invention will be described.

[Second form of ITO particles]
The ITO particles according to the second aspect of the present invention are produced by coating the ITO particles according to the first aspect described above with a hydrolyzate of organosilicon. Against ITO particles of the first aspect of the present invention as described above have a specific surface area by the BET method of 42~65m ² / g, ITO particles of this second embodiment, 50 to 70 m ² / g The specific surface area by the BET method is preferably 55 to 65 m ² / g. If the specific surface area by the BET method is less than 50 m ² / g, there is a problem that haze is increased when a conductive film is formed. If the specific surface area by the BET method exceeds 70 m ² / g, there is a problem that the change in surface resistivity cannot be improved with respect to ultraviolet irradiation. In the ITO particles of the second form, the coating amount of the hydrolyzate of organosilicon is 0.5 to 15 parts by mass, preferably 1 to 10 parts by mass with respect to 100 parts by mass of the ITO particles before coating. If the coating amount is less than 0.5 parts by mass, photodegradation of the ITO conductive film when irradiated with ultraviolet rays cannot be prevented, and if it exceeds 15 parts by mass, the conductivity of the ITO conductive film is lost. The isoelectric point of the ITO particles before coating is around pH 7, and the isoelectric point of the ITO particles after coating is around pH 2. The volume resistivity of the ITO particles before coating is 5 Ωcm or less, and the volume resistivity of the ITO particles after coating is 100 to 50000 Ωcm.

[Method for Producing ITO Particles of Second Form]
The ITO particles of the second form can be produced by the following three methods.
(A-2) A silica sol-gel solution that is a hydrolyzate of organosilicon is impregnated with the ITO particles of the first form described above. The ITO particles impregnated in the silica sol-gel solution are dried, and the dried product is pulverized to obtain ITO particles coated with the hydrolyzate of organosilicon. In this method, the coating amount of the hydrolyzate of organosilicon with respect to 100 parts by mass of the ITO particles before coating is adjusted to 0.5 to 15 by adjusting the ratio of the silica mass in the silica sol-gel solution and the mass of the ITO particles to be impregnated. It is adjusted to the mass part.
(B-2) The silica sol-gel solution which is a hydrolyzate of organosilicon is sprayed while stirring the ITO particles of the first form described above with a dry stirrer. The ITO particles sprayed with the silica sol-gel solution are dried, and the dried product is pulverized to obtain ITO particles coated with the hydrolyzate of organosilicon. In this method, the coating amount of the organosilicon hydrolyzate with respect to 100 parts by mass of the ITO particles before coating is adjusted to 0.5 by adjusting the ratio of the silica mass in the silica sol-gel solution to be sprayed and the mass of the ITO particles to be impregnated. It is adjusted to ˜15 parts by mass.
(C-2) The silicon alkoxide is heated to generate vapor, and the vapor is brought into contact with the ITO particles of the first form described above for a predetermined time. The ITO particles in contact with the vapor are dried, and the dried product is pulverized to obtain ITO particles coated with the hydrolyzate of organosilicon. In this method, the coating amount of the hydrolyzate of organosilicon with respect to 100 parts by mass of the ITO particles before coating is adjusted by adjusting the temperature at which the silicon alkoxide is heated (evaporation amount of silicon alkoxide) and the time for contacting the ITO particles. It is adjusted to 0.5 to 15 parts by mass.

  Drying in the above methods (a-2) to (c-2) is performed in air or a nitrogen atmosphere. When drying in an air atmosphere, the drying temperature is set in the range of 150 to 200 ° C. If the temperature exceeds 200 ° C., the ITO particles are oxidized, and when the ITO conductive film is formed, the conductive film becomes a yellowish film. Moreover, if it is less than 150 degreeC, the light resistance of an ITO electrically conductive film when it is set as an ITO electrically conductive film will deteriorate. When drying is performed in a nitrogen atmosphere, the drying temperature is set in the range of 150 to 700 ° C. When the temperature exceeds 700 ° C., the haze of the conductive film increases when the ITO conductive film is formed, and the transparency of the conductive film is poor. Moreover, if it is less than 150 degreeC, the light resistance of an ITO electrically conductive film when it is set as an ITO electrically conductive film will deteriorate.

  The organosilicon hydrolyzate used in the above methods (a-2) and (b-2) is prepared by adding water to an alcohol solution such as tetramethoxysilane or silicon alkoxide such as tetraethoxysilane, tetrabutoxysilane, or tetraacetoxysilane. It is prepared by adding a mixture of nitric acid and, if necessary, an organic solvent of glycol ether and heating and stirring. Tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, tetraacetoxysilane, or the like is preferable because the resistance change of the conductive film with respect to ultraviolet light is small when the conductive film is formed. Specifically, this hydrolyzate of organosilicon is, first, ethanol and isopropanol in an amount of 1.0 to 100.0 parts by mass with respect to 1 part by mass of tetramethoxysilane or tetraethoxysilane as silicon alkoxide. An organic solvent such as (IPA) or propylene glycol monomethyl ether (PGME) is added, and the first liquid is preferably prepared by stirring at a temperature of 30 to 40 ° C. for 5 to 20 minutes. On the other hand, separately from the first liquid, 0.5 to 5.0 parts by mass of water and 0.005 to 1.0 parts by mass of nitric acid are added to 1 part by mass of the silicon alkoxide. The second liquid is prepared by stirring at a temperature of -40 ° C for 5-20 minutes. Next, the first liquid prepared as described above is preferably maintained at a temperature of 30 to 80 ° C. using a water bath or the like, and then the second liquid is added to the first liquid, preferably in a state where the temperature is maintained. Stir for 30-180 minutes. Thereby, the hydrolyzate of the silicon alkoxide is prepared.

[Method for Producing Composition for Forming ITO Conductive Film of Second Form]
The ITO particles of the second form obtained by the above method are mixed with the binder resin of the first form and the organic solvent of the first form to prepare the ITO conductive film forming composition of the second form. . Since this preparation method is the same as the preparation method of the ITO conductive film forming composition of the first form except that the ITO particles of the second form are used, repeated description is omitted.

[Method for forming ITO conductive film]
The ITO conductive film is formed by, for example, applying the ITO conductive film forming composition of the first or second form obtained above on a film such as polyethylene terephthalate (PET) as a base material by a screen printing method, a bar After coating by a coating method, a die coating method, a doctor blade, a spin method or the like, it is formed by drying at a temperature of 80 to 130 ° C.

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

[Manufacturing of 16 kinds of first form ITO particles]
An aqueous solution of indium chloride and tin dichloride are mixed, and the mixed aqueous solution and an aqueous ammonia solution are added dropwise to water at the same time to adjust the pH and react. The generated precipitate was repeatedly washed with ion-exchange water. When the electrical conductivity of the supernatant became 20 μS / cm or less, the precipitate (In / Sn coprecipitated hydroxide) was filtered off to obtain coprecipitated indium tin hydroxide. The solid-liquid separated indium tin hydroxide was subjected to surface modification treatment by the first to third methods described above, and as shown in Table 1, 16 types (No. 1 to No. 16) of the first The resulting ITO particles were obtained. The No. 16 ITO particles were obtained by firing in a nitrogen atmosphere, and the other No. 1 to No. 15 ITO particles were obtained by firing in an air atmosphere.

For example, No. 1 ITO particles were produced by the following method. First, 50 mL of a raw material indium trichloride (InCl ₃ ) aqueous solution (containing 18 g of In metal) and 3.6 g of a raw material tin dichloride (SnCl ₂ .2H ₂ O) were mixed, and this mixed aqueous solution and ammonia (NH ₃ ). The aqueous solution was simultaneously added dropwise to 500 ml of water, adjusted to pH 7, and reacted at a liquid temperature of 30 ° C. for 30 minutes. Subsequently, the produced precipitate was repeatedly washed with ion-exchanged water by tilting. When the electrical conductivity of the supernatant liquid became 20 μS / cm or less, the precipitate (In / Sn coprecipitated hydroxide) was filtered off to obtain a coprecipitated indium tin hydroxide having an amber color tone of the dry powder. . The solid-liquid separated indium tin hydroxide was dried at 110 ° C. overnight, then calcined in the atmosphere at 550 ° C. for 3 hours, and the aggregate was pulverized and loosened to obtain about 25 g of ITO particles having a bright color. 25 g of the above ITO powder was impregnated in a surface treatment liquid (mixing ratio of 5 parts by weight of distilled water with respect to 95 parts by weight of ethanol) mixed with absolute ethanol and distilled water, and then placed in a glass petri dish and a nitrogen gas atmosphere Then, the particles were heated at 330 ° C. for 2 hours and surface-modified to obtain ITO particles.

  According to this No. 1 production method of ITO particles, the raw materials, the pH during the reaction, the temperature during the reaction, the temperature as the firing condition, and the alcohol reduction temperature as the reforming condition are those of No. 1. Thus, ITO particles No. 2 to No. 16 were obtained. With respect to the obtained 16 kinds of ITO particles No. 1 to No. 16, the specific surface area and L value by the BET method were measured.

  The specific surface area of the 16 kinds of ITO particles of No. 1 to No. 16 in the first form by the BET method was measured using a device (SA-1100) manufactured by Shibata Kagakusha, and the L value was the color of Suga Test Instruments. Measurement was performed using a computer (SM-T). These measurement results are also shown in Table 1.

[Preparation of 21 types of ITO dispersion liquids in the first embodiment]
As shown in Table 2, one of the 16 types of ITO particles of No. 1 to No. 16 in the first form and a dispersant composed of polyoxyethylene alkyl ether phosphate are added to three types of organic solvents. Then, 21 types of ITO dispersions A to U were prepared by dispersing with a wet bead mill. In Table 2, MMB means 3-methoxy-3-methyl-1-butanol, BCA butyl carbitol acetate, and α-T means α-terpineol.

[Preparation of 14 types of resin solutions of the first form]
As shown in Table 3, the same three types of organic solvents as the ITO dispersion liquid were prepared, and ethyl cellulose and terpene phenol resin as binder resins were mixed in the organic solvent, and the mixture was mixed at a temperature of 60 ° C. The binder resin was dissolved by heating at 14 to prepare 14 types of resin solutions of the first form. The terpene phenol resin of the product number made by Yashara Chemical Co., Ltd. was used.

[Preparation of Composition for Forming ITO Conductive Film of Examples 1 to 37 and Comparative Examples 1 to 7]
As shown in Table 4 and Table 5, after diluting each of the 14 types of resin solutions of the first form with a diluting solution to make a resin solution of 25% by mass, a predetermined resin solution is selected from among them, A predetermined ITO dispersion liquid is selected from 21 types of ITO dispersion liquids, the selected resin solution and the selected ITO dispersion liquid are phenolic antioxidants, hindered amine light stabilizers, organosilicon compounds having hydrolyzing groups, By mixing water or water and an additive composed of a leveling material (BYK-313 manufactured by Big Chemi-Japan) and stirring and dispersing with a rotation and revolution mixer, Examples 1 to 37 and Comparative Examples 1 to 7 of the first form An ITO conductive film forming composition was prepared. “MEK” shown in Tables 4 and 5 is methyl ethyl ketone, “BCA” is butyl carbitol acetate, and “EtOH” is ethanol. In Tables 4 and 5, Examples 20 to 32, 35 to 37, and Comparative Example 7 are shown as examples of the composition for forming an ITO conductive film containing an organosilicon compound having a hydrolyzable group, respectively. The “molar ratio” shown in Tables 4 and 5 represents the ratio of the number of moles of water to the number of moles of hydrolyzable groups contained in the organosilicon compound. In Examples 35 to 37 and Comparative Example 7, the components other than ITO particles do not contain water, so this molar ratio is zero.

[Example, ratio of solid content of first form in composition of comparative example, ratio other than ITO particles and ITO particles]
From Tables 4 and 5, the proportions of the solid content of the first form in the compositions of Examples 1 to 37 and Comparative Examples 1 to 7, and the proportions other than ITO particles and ITO particles are summarized. These ratios are shown in Tables 6 and 7.

[Examples, proportions other than ITO particles and ITO particles in the composition of the comparative example, the properties of the ITO particles, the binder resin, the proportion of the dispersant]
From Tables 4 and 5, the proportions other than ITO particles and ITO particles in the compositions of Examples 1 to 37 and Comparative Examples 1 to 7, the physical properties of the ITO particles, the proportions of the binder resin, and the dispersant are summarized. These ratios are shown in Tables 8 and 9.

[Formation of ITO conductive film of first form and evaluation of printability]
The ITO electrically conductive film of the 1st form was formed on the base material for every composition from 44 types of ITO electrically conductive film formation compositions of the 1st form obtained in Examples 1-37 and Comparative Examples 1-7. . Specifically, these compositions were applied to a 40 mm × 40 mm film on a polyethylene terephthalate (PET) film substrate and 1 mm thick glass using a screen printer (manufactured by Mitani Micronics, model number MEC-2400). Each printed in size. After printing, 44 kinds of ITO conductive films were obtained by drying at 130 ° C. for 5 minutes in an air atmosphere. The printability at this time was evaluated. For evaluation of printability, the screen printer was used to visually determine the degree of bleeding after printing and the degree of clogging of the screen. Those that did not cause bleeding after printing and clogging of the screen were evaluated as “good”, those that generated bleeding after printing were defined as “slightly defective”, and those that generated screen clogging were determined as “defective”. The results are shown in Table 10 and Table 11.

[Evaluation of ITO Conductive Film of First Form]
The 44 types of ITO conductive films of the first embodiment formed by the above method were subjected to the following evaluation tests.

(1) Adhesiveness to base material Adhesiveness to the base material was examined by a cross-cut method (based on JISK5600-5-6) for the ITO conductive film on the film base material. In the adhesion test, out of 100 grids, the number of cells remaining without peeling after the test was indicated in the molecule, and the adhesion was evaluated. Specifically, when all 100 squares remain, it is expressed as 100/100, and when the 20th square is peeled and the 80th square remains, it is expressed as 80/100. These results are shown in Table 10 and Table 11.

(2) Transparency A film formed on a glass substrate was measured for total light transmittance and haze using a haze meter (manufactured by Suga Test Instruments, model number HZ-2), and the transparency of the ITO conductive film was measured. The total light transmittance shown in the table is a numerical value including the base material, the total light transmittance of the base material alone was 89%, and the haze was 0.03%. These results are shown in Table 10 and Table 11.

(3) Change in conductivity and surface resistivity under high temperature and high humidity Using Hiresta (model number: MCP-HT450) manufactured by Mitsubishi Chemical Analytech, surface resistivity of ITO conductive film immediately after it was fabricated on a glass substrate (initial The resistivity was measured and the conductivity was evaluated. Then, as a heat resistance test, after storing for 24 hours in a room adjusted to 85 ° C., the rate of change in surface resistivity at the same location as the location where the initial resistivity was measured was determined based on the following formula.
Rate of change (%) = [(surface resistivity after heating−initial surface resistivity) / initial surface resistivity] × 100
In addition, as a moisture resistance test, after storing in a room adjusted to a temperature of 60 ° C. and a relative humidity of 90% for 24 hours, the surface resistivity at the same location as the location where the initial resistivity was measured was measured, and the rate of change was expressed by the following equation: Based on.
Rate of change (%) = [(surface resistivity after humidification−initial surface resistivity) / initial surface resistivity] × 100
These results are shown in Tables 12 and 13.

(4) Composition analysis of ITO conductive film Analysis of the composition of the ITO conductive film was impossible to measure by FT-IR because of the near infrared absorption of ITO. Therefore, a paint having components excluding ITO was prepared, the paint was formed on glass, and measured with FT-IR manufactured by Horiba. First, a solution in which ITO was removed from the composition of Example 1 was prepared, and FT-IR of this solution was measured. Next, this solution was deposited on glass by screen printing, and the FT-IR of the film from which the solvent was removed was measured. It was confirmed that the peak ratio of ethyl cellulose and terpene phenol resin in the solution and the film was the same, and it was confirmed that the charged composition and the film composition were the same.

  As is clear from Tables 10 to 13, in Comparative Example 1, the ratio of the composition other than ITO particles was as high as 60.0% by mass (Table 7) in 100% by mass of the solid content of the composition. Inferior. Moreover, since the ratio of ITO particle | grains was as low as 0.8 mass% (Table 7) in 100 mass% of compositions, the initial surface resistivity of the ITO electrically conductive film was very large, and it was inferior to electroconductivity.

In Comparative Example 2, since the terpene phenol resin was not contained (Table 9), the adhesion of the ITO conductive film to the base material was very poor. Moreover, since the specific surface area of ITO particles was as low as 40 m ² / g (Table 9) and the L value of ITO particles was as high as 39.0 (Table 9), the initial surface resistivity was very large and the conductivity was poor. It was.

  In Comparative Example 3, since the terpene phenol resin is not contained (Table 9), the adhesion of the ITO conductive film to the base material is very poor, and the L value of the ITO particles is 37.2 (Table 9). The initial surface resistivity was large and the conductivity was poor.

In Comparative Example 4, since the specific surface area of the ITO particles was as low as 30 m ² / g (Table 9), the haze of the ITO conductive film was somewhat large and the transparency was poor.

  In Comparative Example 5, since the L value of the ITO particles was 68.0 (Table 9), the initial surface resistivity was large and the conductivity was poor. Moreover, since the ratio of ethylcellulose was as small as 5 mass% (Table 9) in the ratio of ethylcellulose and terpene phenol resin, it was inferior to screen printability.

In Comparative Example 6, since the specific surface area of the ITO particles was as high as 85 m ² / g (Table 9), the total light transmittance of the ITO conductive film was low, the haze was large, and the transparency was poor. Further, since the L value of the ITO particles was 73.5 (Table 9), the initial surface resistivity was large and the conductivity was poor.

  In Comparative Example 7, since the softening point of the terpene phenol resin was as low as 110 ° C. (Table 9), the change in surface resistivity was large even in the heat resistance test at 85 ° C. (Table 13). Furthermore, since the additive amount of the dispersant was as large as 25 parts by mass (Tables 5 and 2) with respect to the ITO particles, the adhesion was inferior and high surface resistivity was exhibited.

  In Examples 35 to 37, since only the organosilicon compound containing a hydrolyzable group without addition of water, the rate of change in surface resistivity after humidification relative to the initial surface resistivity of the ITO conductive film is not so small. The ITO conductive film was not excellent in moisture resistance (Table 13).

On the other hand, since the compositions of Examples 1 to 34 are compositions containing ethyl cellulose capable of increasing the viscosity and a high boiling point solvent of butyl carbitol acetate or α-terpineol, screen properties It was excellent. Further, in 100% by mass of the paste composition, 3-45% by mass of ITO particles are contained. In the solid content of 100% by mass of the composition, 10% to 52% by mass of components other than the ITO particles are contained. A terpene phenol resin having a specific surface area by BET method of ~ 65 m ² / g and an L value of 36 or less, wherein the binder resin has a softening point of 130 to 160 ° C., and a mass ratio of the ethyl cellulose to the terpene phenol resin Is ethyl cellulose: terpene phenol resin = 10-80: 90-20, and 1-15 parts by mass of the dispersant is seen with respect to 100 parts by mass of the liquid ITO particles. It was excellent in adhesion, transparency, conductivity, and heat and humidity resistance. In particular, the compositions of Examples 14 to 19 were able to improve heat resistance by containing a phenolic antioxidant or a hindered amine light stabilizer. In particular, the compositions of Examples 20 to 33 are much more resistant to moisture and adhesion by containing an organosilicon compound containing a hydrolyzable group and water, compared to Examples 35 to 37 that do not contain water. It was excellent.

[Manufacture of six types of ITO particles in the second form]
All the ITO particles (hereinafter referred to as coated ITO particles) coated with six types of organosilicon hydrolysates were prepared by the method (a-2) described above (No. 17 to No. 22).

Coated ITO particles of No. 17: 1.7 g of tetraethoxysilane (0.5 parts by mass in terms of SiO _{2 with} respect to ITO particles) and 130 g of ethanol are stirred and mixed at 25 ° C., 0.1 g of nitric acid, water 3. A solution obtained by stirring and mixing 4 g at 25 ° C. was added, and the mixture was heated and stirred at a temperature of 60 ° C. for 1 hour. To the liquid cooled to room temperature, 100 g of ITO particles were added and stirred for 1 hour, and then the liquid in the slurry was heated and evaporated. As a result, No. 17 coated ITO particles were obtained.

No. 18 coated ITO particles: 7.6 g of tetramethoxysilane (3.0 parts by mass with respect to the ITO particles in terms of SiO ₂ ) and 50 g of ethanol were stirred and mixed at 25 ° C., 0.1 g of nitric acid, water 7. A solution obtained by stirring and mixing 6 g at 25 ° C. was added, and the mixture was heated and stirred at a temperature of 60 ° C. for 1 hour. While stirring 100 g of ITO particles with a stirrer, the above liquid was added dropwise little by little. After recovery, the liquid was heated and evaporated. As a result, No. 18 coated ITO particles were obtained.

No. 19 coated ITO particles: 37.4 g of tetrabutoxysilane (7.0 parts by mass with respect to ITO particles in terms of SiO ₂ ), ethanol 120 g, nitric acid 3.0 g, water 15.0, No. 19 In the same manner as in the production method of the 17 coated ITO particles, No. 19 coated ITO particles were obtained.

No. 20 coated ITO particles: 34.7 g of tetraethoxysilane (10.0 parts by mass with respect to ITO particles in terms of SiO ₂ ), ethanol 150 g, nitric acid 3.0 g, water 18.0, No. 20 In the same manner as in the method for preparing 17 coated ITO particles, No. 20 coated ITO particles were obtained.

Coated ITO particles of No. 21: 29.4 g (15.0 parts by mass with respect to ITO particles in terms of SiO ₂ ) of tetraethoxysilane 3-5 pentamer, ethanol 150 g, nitric acid 3.0 g, water 18. At 0, the coated ITO particles No. 21 were obtained in the same manner as the production method of the coated ITO particles No. 17.

Coated ITO particles of No. 22: 39.2 g of tetraethoxysilane trimer to pentamer (20.0 parts by mass with respect to ITO particles in terms of SiO ₂ ), ethanol 150 g, nitric acid 3.0 g, water 18. At 0, the coated ITO particles of No. 22 were obtained in the same manner as the production method of the coated ITO particles of No. 17.

  The coated ITO particles No. 17 to No. 22 obtained by the above method were dried for 4 hours under the atmosphere and temperature shown in Table 14, respectively. The specific surface area by BET method of the obtained coated ITO particles was measured using an apparatus (SA-1100) manufactured by Shibata Kagaku. The measurement results are shown in Table 14. Further, the amount of Si in the obtained coated ITO particles was measured by ICP and confirmed to be the same as the charged value.

[Preparation of Six Kinds of ITO Dispersions in the Second Form]
As shown in Table 15, the organic solvent 3-methoxy-3-methyl-1-butanol (MMB) is coated with any one of the six types of coated ITO particles of No. 17 to No. 22 described above, A dispersant composed of oxyethylene alkyl ether phosphate was added and dispersed by a wet bead mill to prepare six types of ITO dispersions V to AA.

[Preparation of Composition for Forming ITO Conductive Film of Second Form of Examples 38 to 43 and Comparative Example 8]
The resin solution m of the first form, the six kinds of dispersion liquids of the second form, and butyl carbitol acetate (BCA) as a dilution medium are mixed at a ratio shown in Table 16 and stirred with a rotation and revolution mixer. The composition for ITO conductive film formation of the 2nd form of Examples 38-43 and the comparative example 8 was prepared by disperse | distributing. In Example 43, the product name AO-20 manufactured by ADEKA, which is a phenolic antioxidant, was added as an additive at a ratio shown in Table 16.

[Example, ratio of solid content of second form in composition of comparative example, ratio other than ITO particles and ITO particles]
The ratio of the solid content of the second form in the compositions of Examples 38 to 43 and Comparative Example 8, and the ratios other than ITO particles and ITO particles are summarized. These ratios are shown in Table 17.

[Examples, proportions other than ITO particles and ITO particles in the composition of the comparative example, the properties of the ITO particles, the binder resin, the proportion of the dispersant]
The proportions of the compositions of Examples 38 to 43 and Comparative Example 8 other than ITO particles and ITO particles, the physical properties of the ITO particles, the binder resin, and the proportion of the dispersant were summarized. These ratios are shown in Table 18.

[Formation of ITO Conductive Film of Second Form, Printability of Composition, and Evaluation of ITO Conductive Film of Second Form]
From the seven types of ITO conductive film forming compositions of the second form obtained in Examples 38 to 43 and Comparative Example 8, the ITO conductive film of the second form is formed for each composition in the same manner as the first form. Printability of the composition formed on the base material as in the first form, adhesion of the ITO conductive film of the second form to the base material, transparency, and conductivity and the surface under high temperature and high humidity The change in resistivity was evaluated. The rate of change in surface resistivity at high temperatures was determined in the same manner as in the first embodiment after 72 hours of storage in a room adjusted to 85 ° C. The rate of change in surface resistivity under high humidity was determined in the same manner as in the first embodiment after 72 hours of storage in a room adjusted to a temperature of 60 ° C. with a relative humidity of 90%. The evaluation method for other items is the same as the evaluation method of the first embodiment. These results are shown in Table 19 and Table 20.

[Evaluation of Light Resistance of ITO Conductive Film of Second Form]
The light resistance of the seven types of ITO conductive films of the second form formed by the above method was evaluated. Specifically, an ITO conductive film formed on a base material is placed in a room adjusted to a temperature of 63 ° C. with a relative humidity of 50%, and an ultraviolet irradiation device (Isuperki UV Tester SUV, manufactured by Iwasaki Electric Co., Ltd.) is applied to the ITO conductive film. -W16), an ultraviolet ray having an illuminance of 0.15 W / cm ² and an integrated light amount of 270 J / cm ² was irradiated for 30 minutes. The initial surface resistivity before irradiation and the surface resistivity after irradiation were measured, and the rate of change was determined based on the following equation.
Rate of change (%) = [(surface resistivity after UV irradiation−initial surface resistivity) / initial surface resistivity] × 100
The results are shown in Table 21.

As is apparent from Tables 14 to 21, in Comparative Example 8, an ITO dispersion liquid was prepared using No. 22 ITO particles having an organic silicon hydrolyzate covering amount of 20.0 parts by mass (Table 14). In addition, since the specific surface area of the ITO particles was 80 m ² / g (Table 18), the total light transmittance, which is the transparency evaluation of the ITO conductive film obtained from the dispersion, was 85.0% (Table 19). ) And haze was as high as 3.0%. Moreover, the initial surface resistivity exceeds the measurement range of Hiresta (Tables 20 and 21), and is described as “Over”. ) Electrical conductivity could not be expressed.

On the other hand, the compositions of Examples 38 to 43 are compositions containing ethyl cellulose capable of increasing the viscosity and a high boiling point solvent of butyl carbitol acetate or α-terpineol. It was excellent. Furthermore, in 100% by mass of the paste composition, 14.0 to 31.5% by mass of ITO particles are contained, and in a solid content of 100% by mass of the composition, components other than the ITO particles are contained in an amount of 10.0 to 30% by mass. The ITO particles have a specific surface area according to the BET method of 50 to 70 m ² / g, the binder resin contains a terpene phenol resin having a softening point of 160 ° C., and the mass ratio of the ethyl cellulose to the terpene phenol resin is ethyl cellulose. : Terpene phenol resin = 30: 70 or 20:80, and the dispersant is 5 parts by mass with respect to 100 parts by mass of the liquid ITO particles. Therefore, the ITO conductive material made from the compositions of Examples 35 to 40 The film was excellent in adhesion to the substrate, transparency, conductivity, and heat and humidity resistance. In particular, the ITO conductive film made from the compositions of Examples 38 to 43 had a change rate within −10% before and after UV irradiation, and was excellent in light resistance.

Claims (14)

In the composition for forming an ITO conductive film containing ITO particles, a binder resin, and an organic solvent,
In 100% by mass of the composition, the ITO particles are included in an amount of 3 to 45% by mass. In the solid content of 100% by mass of the composition, the components other than the ITO particles are included in an amount of 10 to 52% by mass.
The ITO particles have a specific surface area according to the BET method of 42 to 65 m ² / g and an L value of 36 or less,
The composition for forming an ITO conductive film, wherein the binder resin contains ethyl cellulose and a terpene phenol resin having a softening point of 130 to 160 ° C.   2. The composition for forming an ITO conductive film according to claim 1, wherein a mass ratio between the ethyl cellulose and the terpene phenol resin is ethyl cellulose: terpene phenol resin = 10-80: 90-20.   The composition for ITO electrically conductive film formation of Claim 1 or 2 which further contains 1-15 mass parts of dispersing agents with respect to 100 mass parts of said liquid ITO particle | grains.   The composition for ITO electrically conductive film formation of any one of Claim 1 thru | or 3 used for the paste for screen printing, or a coating material.   When used for the screen printing paste, the organic solvent comprises 3-methoxy-3-methyl-1-butanol and a solvent of butyl carbitol acetate or α-terpineol. Composition.   When used in the paint, the organic solvent is 3-methoxy-3-methyl-1-butanol, 2-butanone, 4-methyl 2-pentanone, ethanol, 2-propanol, 1-butanol, toluene, methanol, 1 The composition for forming an ITO conductive film according to claim 4, comprising one or more solvents selected from the group consisting of -propanol, ethyl acetate, butyl acetate, acetone, 2,4-pentanedione and xylene.   7. The ITO conductive film formation according to claim 1, further comprising 0.1 to 5% by mass of a phenolic antioxidant or a hindered amine light stabilizer in a solid content of 100% by mass of the composition. Composition.   An organic silicon compound having a hydrolyzable group and water, wherein the content of the organic silicon compound is 5 to 52% by mass in 100% by mass of the solid content of the composition, and the water content is The hydrolyzable group contained in the organosilicon compound having a decomposable group is a methoxy group or an ethoxy group, and the mol number is 0.05 to 0.7 times the mol number of the hydrolyzed group. The composition for forming an ITO conductive film according to any one of the above items. The ITO particles are coated with an organosilicon hydrolyzate, and the ITO particles coated with the organosilicon hydrolyzate have a specific surface area of 50 to 70 m ² / g by the BET method, and the organosilicon hydrolyzate The composition for forming an ITO conductive film according to any one of Claims 1 to 7, wherein the coating amount is 0.5 to 15 parts by mass with respect to 100 parts by mass of the ITO particles before coating. ITO particles having a specific surface area of 42 to 65 m ² / g BET method and an L value of 36 or less are uniformly dispersed in a terpene phenol resin having a softening point of 130 to 160 ° C. An ITO conductive film containing 48 to 90% by mass and 10 to 52% by mass of components other than the ITO particles.   The ITO electrically conductive film of Claim 10 which further contains 0.1-5 mass% in 100 mass% of solid content of the said composition in a component other than the said ITO particle | grains in phenolic antioxidant or a hindered amine light stabilizer.   In the components other than the ITO particles, further comprising an organosilicon compound having a hydrolyzable group and water, and the content of the organosilicon compound is 5 to 52% by mass in 100 mass of the solid content of the composition, The water content is such that the hydrolyzable group contained in the organosilicon compound having a hydrolyzable group is a methoxy group or an ethoxy group, and 0.05 to 0.7 times mol per mol of the hydrolyzable group. The composition for forming an ITO conductive film according to claim 10, which is a number. An ITO particle coated with a hydrolyzate of organosilicon having a specific surface area of 50 to 70 m ² / g by the BET method is uniformly dispersed in a terpene phenol resin having a softening point of 130 to 160 ° C. Medium containing 70 to 90% by mass of ITO particles coated with the hydrolyzate of organosilicon and 10 to 30% by mass of components other than ITO particles coated with the hydrolyzate of organosilicon. The ITO electrically conductive film whose coating amount of a hydrolyzate is 0.5-15 mass parts with respect to 100 mass parts of said ITO particles before coating.   The ITO electrically conductive film of Claim 13 which further contains a phenolic antioxidant or a hindered amine light stabilizer in components other than the ITO particle | grains coat | covered with the hydrolyzate of the said organosilicon.