JP4699156B2 - Gas barrier film - Google Patents

Description

  The present invention relates to a gas barrier film useful for packaging foods, pharmaceuticals, etc., or for electronic members such as film liquid crystal displays and organic EL displays.

  Gas barrier films are used for packaging foods, pharmaceuticals, chemicals and the like in order to prevent permeation of water vapor and oxygen. A gas barrier film having a high gas barrier property is used for applications that require better water vapor and oxygen permeation preventive properties in order to prevent deterioration of the contents.

  As such a gas barrier film, one having a structure in which a gas barrier layer is formed on one side or both sides of a plastic film as a base material is generally used. This gas barrier layer is formed by various methods such as a CVD method and a PVD method.

  For example, there has been proposed a gas barrier film in which a deposited film of an inorganic oxide such as silicon oxide, aluminum oxide, magnesium oxide or the like is formed as a gas barrier layer on a substrate by a PVD method (see, for example, Patent Document 1). Such a gas barrier film is very excellent in gas barrier properties and has an advantage that the contents can be confirmed from the outside because it is transparent. However, the vapor deposition film is formed by stacking inorganic oxide particles, and the film always includes a defect structure. Therefore, even if the film formation method is changed, the gas barrier property is limited.

  In addition, in gas barrier films used for food packaging, since a large area and productivity are regarded as important, it is common to deposit a vapor deposition film on a substrate continuously at a high speed with a roll. . The vapor deposition film includes a defect structure as described above, but the vapor deposition film formed in this way tends to be a film having more defect structures. Thus, in the vapor deposition film, structural defects are likely to occur on the manufacturing surface, and it is difficult to maintain gas barrier properties.

  Furthermore, for example, a gas barrier film is proposed in which a vapor barrier film of an inorganic oxide such as silicon oxide or aluminum oxide is formed on a substrate as a gas barrier layer by a low temperature plasma chemical vapor deposition method which is a kind of CVD method (for example, Patent Documents). 2-4). The low-temperature plasma chemical vapor deposition method has an advantage that there is little thermal damage to the substrate, but, like the PVD method, there is a problem that the gas barrier property is limited due to the defect structure in the film.

  Thus, the conventional gas barrier film still has insufficient oxygen permeability and water vapor permeability when used in applications requiring high gas barrier properties. Moreover, although it is possible to improve gas barrier property by making a vapor deposition film thick, cost will become very high.

Japanese Patent Laid-Open No. 4-7139 JP-A-8-176326 Japanese Patent Laid-Open No. 11-309815 JP 2000-6301 A

  This invention is made | formed in view of the said problem, and is a gas barrier film which has a vapor deposition film, Comprising: It aims at providing an inexpensive gas barrier film excellent in gas barrier property.

  In order to achieve the above object, the present invention provides a substrate made of a resin, a first inorganic layer that is formed on the substrate and is a vapor deposition film, an ultrafine particle formed on the first inorganic layer. A gas barrier film comprising a second inorganic layer that is a formed film is provided.

According to the present invention, since the second inorganic layer is a film formed of ultrafine particles, even if defects such as pinholes are present in the first inorganic layer that is the deposited film, the defects such as pinholes are caused by the ultrafine particles. Can be blocked. For this reason, it can prevent that water vapor | steam, oxygen, etc. permeate from defects, such as a pinhole of a 1st inorganic layer. In addition to the surface defects such as pinholes and foreign matters, the deposited film also has structural defects. Such defective portions are structurally weak, but the ultrafine particles are structurally weak due to the size effect of the ultrafine particles. Since it enters into a weak part, the filling density of a vapor deposition film can be improved and gas barrier property can be improved. In particular, in order to efficiently produce a large-area gas barrier film, when a vapor deposition film is formed on a substrate continuously at a high speed with a roll, it tends to be a vapor deposition film with many structural defects. Since ultrafine particles enter the defective portion of the deposited film, the gas barrier property can be remarkably improved and the gas barrier property can be maintained when the deposited film has many structural defects.
In addition, when the second inorganic layer is formed by applying and baking an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent, the sintering temperature is set higher than the normal sintering temperature due to the size effect unique to the ultrafine particles. Can also be lowered. Thereby, it is possible to use a base material having relatively low heat resistance. Furthermore, by providing the second inorganic layer on the first inorganic layer, it is possible to prevent the intrusion of water vapor and oxygen as described above, so there is no need to provide a thick vapor deposition film in order to obtain gas barrier properties. Manufacturing costs can be reduced.

  In the said invention, the said 1st inorganic layer may consist of a some vapor deposition film. This is because gas barrier properties can be further improved by laminating a plurality of deposited films (first inorganic layer) and a film (second inorganic layer) formed of ultrafine particles.

  In the present invention, the sintering temperature of the ultrafine particles is preferably 350 ° C. or lower. This is because, by using ultrafine particles having a sintering temperature in the above range, when the second inorganic layer is formed by applying and firing an ultrafine particle dispersion, firing can be performed at a lower temperature.

  Furthermore, in the present invention, the ultrafine particles are preferably at least one kind of ultrafine particles selected from the group consisting of indium oxide, silicon oxide, silicon nitride, and silicon oxynitride. Moreover, it is also preferable that the ultrafine particles are at least one kind of ultrafine particles selected from the group consisting of indium, alkali metal, and alkaline earth metal. This is because by using these ultrafine particles, a second inorganic layer having desired characteristics can be obtained.

  Furthermore, in the present invention, it is preferable that the average particle diameter of the ultrafine particles is in the range of 0.5 nm to 100 nm. This is because ultrafine particles having an average particle size that is too small are difficult to produce, and if the average particle size of the ultrafine particles is too large, it may be difficult to block defects such as pinholes in the first inorganic layer.

  The present invention also provides a first inorganic layer forming step of forming at least one vapor-deposited film on a resin substrate, and an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent on the first inorganic layer. And a second inorganic layer forming step of baking and forming a film. A method for producing a gas barrier film is provided.

According to the present invention, even when defects such as pinholes are present in the first inorganic layer that is the deposited film, the second inorganic layer is formed by applying the ultrafine particle dispersion on the first inorganic layer. It can block defects such as pinholes. Therefore, a gas barrier film excellent in gas barrier properties can be obtained. Further, it is not necessary to provide a thick deposited film as in the prior art, so that the manufacturing cost can be reduced and the yield can be improved.
Furthermore, according to the present invention, in the second inorganic layer forming step, sintering can be performed at a temperature lower than the normal temperature due to the size effect unique to the ultrafine particles. Thereby, baking below the heat-resistant temperature of a base material is attained.

  In the said invention, it is preferable to bake in the atmosphere which the said ultrafine particle does not oxidize at the said 2nd inorganic layer formation process, and to bake in oxidizing atmosphere after that. This is because the ultrafine particles can be sufficiently sintered to form a dense film.

  In the present invention, in the first inorganic layer forming step, after forming a lower vapor deposition film on the substrate and polishing the surface of the lower vapor deposition film, the upper vapor deposition is performed on the lower vapor deposition film. A film may be formed. For example, when foreign matter exists on the surface of the lower vapor deposition film, the foreign matter can be removed by polishing, and the gas barrier property of the portion where the foreign matter is present can be reinforced by further forming the vapor deposition film thereon. is there.

  Furthermore, in the present invention, the boiling point of the solvent is preferably 120 ° C. or higher. If the boiling point of the solvent is relatively high, it is possible to prevent the solvent from evaporating at the time of drying after application of the ultrafine particle dispersion, thereby preventing the ultrafine particles from agglomerating and losing the flatness of the film. Because it can.

  According to the present invention, since the second inorganic layer, which is a film formed of ultrafine particles, is formed on the first inorganic layer, which is a vapor deposition film, pinholes and the like that are present in the first inorganic layer by the ultrafine particles. Defects can be closed, and the barrier property against water vapor, oxygen, etc. can be improved.

  Hereinafter, the gas barrier film of the present invention and the production method thereof will be described in detail.

A. Gas barrier film First, the gas barrier film of this invention is demonstrated.
The gas barrier film of the present invention includes a base material made of a resin, a first inorganic layer formed on the base material as a vapor deposition film, and a film formed on the first inorganic layer and formed of ultrafine particles. It has a certain 2nd inorganic layer, It is characterized by the above-mentioned.

The gas barrier film of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of the gas barrier film of the present invention. As shown in FIG. 1, the gas barrier film 10 of the present invention is obtained by sequentially laminating a first inorganic layer 2 and a second inorganic layer 3 on a substrate 1 made of a resin.

The first inorganic layer is a deposited film, and the second inorganic layer is a film formed of ultrafine particles. In general, a deposited film formed by a deposition method such as a sputtering method or a vacuum deposition method often has foreign matters such as particles or pinholes, but in the present invention, ultrafine particles are formed on the first inorganic layer which is a deposited film. Since the second inorganic layer, which is a film formed of, is laminated, defects on the production surface of the deposited film, microscopic structural defects, etc. can be closed with ultrafine particles, and high barrier properties against water vapor and oxygen are obtained. Can be realized.
Further, the deposited film has structural defects in addition to surface defects such as pinholes and foreign matters, and such defective portions are structurally weak portions. In addition, when the foreign matter in the vapor deposition film is removed by polishing and a vapor deposition film is further formed thereon, a layer without pinholes can be formed, but the portion where the foreign matter has been removed by polishing is the upper layer. Even if it is covered with a deposited film, it is structurally weak. On the other hand, according to the present invention, since the ultrafine particles enter the structurally weak part due to the size effect of the ultrafine particles, the packing density of the vapor deposition film can be improved and the gas barrier property can be improved. In particular, in order to efficiently produce a large-area gas barrier film, when a vapor deposition film is formed on a substrate continuously at a high speed with a roll, it tends to be a vapor deposition film with many structural defects. Since ultrafine particles enter the defective portion of the deposited film, the gas barrier property can be remarkably improved when the deposited film has many structural defects.

  In addition, when the second inorganic layer is formed by applying and baking an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent, the sintering temperature is set to a normal sintering temperature due to the size effect unique to the ultrafine particles. It can be lowered compared with. Therefore, it is possible to use a base material having relatively low heat resistance.

  Furthermore, in the present invention, since the barrier property against water vapor and oxygen can be obtained by providing the first inorganic layer and the second inorganic layer, it is not necessary to provide a thick deposited film as in the prior art. Cost reduction and yield improvement can be achieved.

Moreover, since the average particle diameter of the ultrafine particles in the present invention is smaller than the wavelength in the visible light region, light scattering by the ultrafine particles can be suppressed. For this reason, it can be set as the 2nd inorganic layer which has high transparency.
Hereinafter, each structure of such a gas barrier film is demonstrated.

1. 2nd inorganic layer The 2nd inorganic layer used for this invention is a film | membrane formed on the 1st inorganic layer mentioned later, and was formed with the ultrafine particle.
Here, the “film formed of ultrafine particles” refers to a film obtained by applying and baking an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent. A film formed of ultrafine particles can be confirmed by a scanning electron microscope (SEM) observation photograph (magnification: 50,000 times or more). FIGS. 2A and 2B show examples of SEM photographs of the cross section and top surface of the film formed of ultrafine particles, respectively. For comparison, FIG. 3 shows an example of a SEM photograph of a cross section of a deposited film formed by sputtering. As illustrated in FIG. 3, columnar particles can be confirmed in the cross section in the deposited film. On the other hand, as illustrated in FIG. 2, in the film formed of ultrafine particles, columnar particles cannot be confirmed on either the top surface or the cross section. Therefore, in the SEM photograph of the cross section of the second inorganic layer, when columnar particles cannot be confirmed, it can be said that the second inorganic layer is a film formed of ultrafine particles.
In addition, although the film formed by the sol-gel method cannot confirm columnar particles, the sol-gel method applies a coating liquid that is a liquid at a molecular level and cures it to form a film. Since a film is formed by sintering ultrafine particles, a film formed by a sol-gel method and a film formed by ultrafine particles are structurally different. Note that the difference in film structure can be confirmed by high-magnification SEM observation.

  The “ultrafine particles” are fine particles made of an inorganic material having an average particle diameter of 100 nm or less, and are fine particles that are individually and uniformly dispersed in a dispersion medium. For such ultrafine particles, reference can be made to JP-A Nos. 2002-121437 and 2005-81501.

The ultrafine particles used in the present invention are not particularly limited as long as they exhibit gas barrier properties, and are appropriately selected according to the use of the gas barrier film.
Examples of the ultrafine particles include inorganic oxides, inorganic nitrides, and ultrafine particles of inorganic oxynitrides. Specifically, inorganic oxides include indium oxide, silicon oxide, aluminum oxide, titanium oxide, tantalum oxide, zinc oxide, magnesium oxide, tin oxide, yttrium oxide, germanium oxide, calcium oxide, boron oxide, strontium oxide, and oxide. Examples include barium, lead oxide, zirconium oxide, sodium oxide, lithium oxide, and potassium oxide. Examples of the inorganic nitride include silicon nitride, aluminum nitride, titanium nitride, and silicon carbonitride. Examples of inorganic oxynitrides include silicon oxynitride. These may be used alone or in combination of two or more. Further, a mixed system of inorganic oxide and inorganic nitride may be used.
In addition, as the ultrafine particles, metal ultrafine particles can also be used. Specifically, the metals include In, Al, Ti, Ta, Zn, Sn, Y, Ge, Pb, Zr, alkali metals (Li, Na, K), alkaline earth metals (Mg, Ca, Sr, Ba). ) And the like.
Further, as the ultrafine particles, ultrafine particles of metal whose surface is oxidized can also be used. Examples of the metal include those described above.

When the gas barrier film of the present invention is used, for example, as a packaging material for foods, pharmaceuticals, etc., it is preferable to use an ultrafine particle having high safety. Moreover, it is preferable that the ultrafine particles have transparency so that the contents can be confirmed from the outside. Examples of such ultrafine particles include inorganic oxide, inorganic nitride, and inorganic oxynitride ultrafine particles, metal ultrafine particles, and metal ultrafine particles whose surface is in an oxidized state. Those having the above properties may be appropriately selected.
In this case, among the above, at least one kind of ultrafine particles selected from the group consisting of silicon oxide, silicon nitride, and silicon oxynitride is preferably used. The film formed of ultrafine particles of silicon oxide, silicon nitride, or silicon oxynitride has good affinity with the first inorganic layer, high manufacturing stability and safety, and is advantageous in terms of cost. is there.
In this case, indium oxide, indium, and indium ultrafine particles whose surface is oxidized are also preferably used. When forming the second inorganic layer by applying and baking an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent, the sintering temperature can be lowered by using such ultrafine particles containing indium. Because it can be done.

In addition, when the gas barrier film of the present invention is applied to, for example, an organic EL display, the ultrafine particles preferably have insulating properties and transparency. This is because the gas barrier film applied to the organic EL display is required to have insulation and transparency. Examples of such ultrafine particles include the above-described inorganic oxide, inorganic nitride, and inorganic oxynitride ultrafine particles, and metal ultrafine particles whose surface is oxidized.
In this case, among the above, at least one kind of ultrafine particles selected from the group consisting of indium oxide, silicon oxide, silicon nitride, and silicon oxynitride is preferably used. This is because the insulating properties can be improved by using these ultrafine particles. Further, when the second inorganic layer is formed by applying and baking an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent, the sintering temperature is lowered by using ultrafine particles of indium oxide. Because it can. Furthermore, the film formed of silicon oxide, silicon nitride, and silicon oxynitride ultrafine particles has good adhesion to the first inorganic layer and the like.
In this case, at least one kind of ultrafine particles selected from the group consisting of In (indium), alkali metal, and alkaline earth metal whose surface is oxidized is also preferably used. This is because indium, alkali metal, and alkaline earth metal are highly oxidizable, so that oxidation is promoted even by firing at a relatively low temperature. The ultrafine metal particles whose surface is oxidized have an insulating property.

The ultrafine particles preferably have a sintering temperature of 350 ° C. or lower. By using ultrafine particles having a sintering temperature in the above range, the firing temperature when forming the second inorganic layer can be lowered. In addition, the lower the sintering temperature of the ultrafine particles, the better, but the lower limit is usually about 180 ° C. Some metals have a melting point of less than 180 ° C., and the sintering temperature of ultrafine particles containing such a metal is usually less than 180 ° C., but a metal having a melting point of less than 180 ° C. is very oxidized. The lower limit of the sintering temperature is within the above range because it is easy to do and leads to an increase in the sintering temperature.
Here, sintering refers to a phenomenon in which when an aggregate of ultrafine particles is heated to a high temperature, it is baked and solidified into a dense polycrystalline body. The ultrafine particles are in a thermodynamically non-equilibrium state, and mass transfer occurs in the direction of decreasing the surface area. As a result, bonding occurs between the particles and the particles become dense. That is, the driving force for sintering is a force that attempts to minimize the surface energy of the system. The sintering temperature is a temperature at which the ultrafine particles become dense and baked when the aggregate of ultrafine particles is heated at a temperature below the melting point of the ultrafine particles.
In the present invention, the sintering temperature can be measured by differential thermal analysis (DTA). In DTA, a temperature difference between a sample and a reference material (generally alumina) can be measured to obtain a transition temperature, and a temperature difference (sample) generated when heat is applied to the sample and the reference material. Thus, the sintering temperature can be determined. That is, when the sample and the reference material are heated in the same atmosphere, the temperature of the reference material is increased, whereas when the sample temperature is not increased, heat is applied to the sintering of the ultrafine particles. It can be said that an endothermic phenomenon has occurred. Therefore, the temperature at which the endothermic phenomenon is observed, that is, the endothermic start temperature in the DTA curve is defined as the sintering temperature in the present invention.
Note that a TG-DTA apparatus (TG 8120) manufactured by Rigaku is used for the measurement of the sintering temperature.

  Further, the ultrafine particles preferably contain a metal having a melting point of about 700 ° C. or lower. This is because if the melting point of a single metal is relatively low as in the above range, the sintering temperature of the ultrafine particles is expected to be relatively low. Examples of such metal include Al (660 ° C.), In (156.4 ° C.), Mg (651 ° C.), Sn (231.85 ° C.), Zn (419.43 ° C.), Pb (327.5 ° C.). ), Na (97.5 ° C.), Li (186 ° C.), K (62.3 ° C.) and the like. The numbers in parentheses are melting points.

  The ultrafine particles may be the same material as or different from the material used for the first inorganic layer described later, but are preferably the same material. This is because the same material can reduce the film stress and has good adhesion.

Further, the average particle diameter of the ultrafine particles may be any as long as it can close defects such as pinholes in the first inorganic layer, and is specifically preferably in the range of 0.5 nm to 100 nm. Preferably it is 1 nm-50 nm, More preferably, it exists in the range of 1 nm-10 nm. If the average particle size is too small, it is difficult to produce. On the other hand, if the average particle size is too large, it may be difficult to close defects such as pinholes in the first inorganic layer. This is because a decrease in the sintering temperature due to this cannot be expected.
In addition, the said average particle diameter can be confirmed with a scanning electron microscope (SEM) observation photograph (high magnification).

The second inorganic layer used in the present invention may or may not have transparency, and is appropriately selected according to the use of the gas barrier film.
When transparency is required for the second inorganic layer, the transmittance of the second inorganic layer in the visible light region is preferably 60% or more, more preferably 80% or more, and particularly preferably 90% or more. .
On the other hand, when transparency is not required for the second inorganic layer, the transmittance of the second inorganic layer in the visible light region is preferably 50% or less. In order to obtain the second inorganic layer having a transmittance of 50% or less, for example, ultrafine metal particles may be used, or the second inorganic layer may be made thick. In general, since a metal film has a higher gas barrier property than a film made of inorganic oxide or the like, the gas barrier property can be enhanced by using ultrafine metal particles. The gas barrier property can also be improved by making the second inorganic layer thick. Thus, gas barrier properties can be improved by setting the transmittance of the second inorganic layer to 50% or less.
In addition, the said transmittance | permeability is an average value of the value measured using Shimadzu Corporation Corp. UV-3100 within the wavelength range of 380 nm-800 nm.

  The thickness of the second inorganic layer is not particularly limited as long as it can close defects such as pinholes in the first inorganic layer. Specifically, the thickness is within a range of 5 nm to 2000 nm. It can set, Preferably it exists in the range of 50 nm-500 nm. This is because if the film thickness of the second inorganic layer is too thick, the transmittance may be lowered, or peeling from the first inorganic layer may occur. On the other hand, if the film thickness of the second inorganic layer is too thin, it is difficult to block pinholes and the like present in the first inorganic layer.

In the present invention, it is preferable to form the second inorganic layer by applying and baking an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent. That is, the second inorganic layer is preferably a coating film formed with ultrafine particles. By forming the second inorganic layer by such a method, pinholes can be effectively blocked with ultrafine particles, and the sintering temperature is lowered to, for example, the heat resistance temperature of the substrate or lower due to the size effect unique to ultrafine particles. can do.
In addition, since the formation method of a 2nd inorganic layer is described in the term of the "B. manufacturing method of a gas barrier film" mentioned later, description here is abbreviate | omitted.

2. 1st inorganic layer The 1st inorganic layer used for this invention is a vapor deposition film.
A method for forming the first inorganic layer is not particularly limited as long as it is a vapor deposition method. In addition, about the formation method of a 1st inorganic layer, since it describes in the term of the "B. manufacturing method of a gas barrier film" mentioned later, description here is abbreviate | omitted.

The first inorganic layer is not particularly limited as long as it exhibits gas barrier properties, and is appropriately selected depending on the use of the gas barrier film. When transparency and insulation are required for the first inorganic layer, for example, inorganic oxides, inorganic nitrides, inorganic oxynitrides, and the like are preferably used. Specifically, inorganic oxides include indium oxide, silicon oxide, aluminum oxide, titanium oxide, tantalum oxide, zinc oxide, magnesium oxide, tin oxide, yttrium oxide, germanium oxide, calcium oxide, boron oxide, strontium oxide, and oxide. Examples include barium, lead oxide, zirconium oxide, sodium oxide, lithium oxide, and potassium oxide. Examples of the inorganic nitride include silicon nitride, aluminum nitride, titanium nitride, and silicon carbonitride. Examples of inorganic oxynitrides include silicon oxynitride. On the other hand, when the first inorganic layer is not particularly required to be transparent or insulating, a metal can be used, for example, Si, Al, Zr, Ti, Sn, In, Zn, Sb, Fe, Ni, Co, Cu, Ag, etc. are mentioned. These may be used alone or in combination of two or more.
Among the above, at least one selected from the group consisting of silicon oxide, silicon nitride, and silicon oxynitride is preferably used. These materials have good adhesion to the base material, the second inorganic layer, etc., have good affinity with the second inorganic layer, have high production stability and safety, and are advantageous in terms of cost. Because.

  The first inorganic layer may be a single-layer vapor deposition film or may be a laminate of a plurality of vapor deposition films. FIG. 4 shows an example of the gas barrier film 10 having the first inorganic layer 2 in which the two vapor-deposited films 12a and 12b are laminated. As shown in FIG. 4, when the pinhole P1 is present in the lower vapor deposition film 12a, the gas barrier property of the pinhole P1 portion may be lowered if the second inorganic layer is formed directly on the vapor deposition film 12a, for example, although not shown. There is sex. On the other hand, when two layers of vapor deposition films 12a and 12b are laminated as illustrated in FIG. 4, an upper vapor deposition film 12b is formed in the pinhole P1 portion of the lower vapor deposition film 12a. 2 Since the inorganic layer 3 is formed, it is possible to prevent the gas barrier property of the pinhole P1 portion from being lowered. Even if the pinhole P2 exists in the upper vapor deposition film 12b, the lower vapor deposition film 12a is formed below the pinhole P2 portion of the upper vapor deposition film 12b, and the second inorganic layer 3 is formed thereon. Therefore, the deterioration of the gas barrier property of the pinhole P2 portion can be prevented similarly. When laminating a plurality of vapor deposition films, it is considered very rare that pinholes are generated in the same part in the upper and lower vapor deposition films. Therefore, the first inorganic layer composed of the plurality of vapor deposition films and the second inorganic layer are combined. By laminating, it is possible to further improve the gas barrier property. In addition to surface defects such as pinholes due to foreign substances, the deposited film has structural defects, etc. Even if the upper deposited film is formed, the pinhole part of the lower deposited film is structurally weak. Since ultrafine particles enter such a structurally weak portion, the filling density of the deposited film is improved and the gas barrier property is improved.

  When the first inorganic layer is a laminate of a plurality of vapor deposition films, the number of vapor deposition films is not particularly limited, but is usually about 2 to 4 layers, preferably 2 layers or 3 layers. This is because if the number of laminated layers is too large, the transmittance is lowered and the cost is increased. At this time, the combination of the deposited films to be stacked may be the same or different.

The first inorganic layer used in the present invention may or may not have transparency, and is appropriately selected according to the use of the gas barrier film.
When transparency is required for the first inorganic layer, the transmittance of the first inorganic layer in the visible light region is preferably 60% or more, more preferably 80% or more, and particularly preferably 90% or more. .
On the other hand, when the transparency of the first inorganic layer is not required, the transmittance of the first inorganic layer in the visible light region is preferably 50% or less. In order to obtain the first inorganic layer having a transmittance of 50% or less, for example, a metal is used, or a metal-rich vapor deposition film is formed by using a metal and an inorganic oxide together, or the first inorganic layer is a thick film. Or just do it. In general, a metal vapor deposition film has a higher gas barrier property than a vapor deposition film such as an inorganic oxide. Therefore, the gas barrier property can be enhanced by using a metal vapor deposition film or a metal rich vapor deposition film. The gas barrier property can also be improved by making the first inorganic layer thick. Thus, the gas barrier property can be improved by setting the transmittance of the first inorganic layer to 50% or less.
In addition, about the measuring method of the said transmittance | permeability, it is the same as that of the method described in the term of the said 2nd inorganic layer.

  The film thickness of the first inorganic layer is appropriately selected depending on the materials described above. Usually, it exists in the range of 5 nm-5000 nm, Preferably it exists in the range of 5 nm-500 nm. Further, when aluminum oxide or silicon oxide is used, it is more preferably in the range of 10 nm to 300 nm. It is because there exists a possibility that gas barrier property may fall when the film thickness of a 1st inorganic layer is too thin. On the other hand, if the film thickness of the first inorganic layer is too thick, cracks or the like may occur during the formation of the first inorganic layer, and the transmittance may decrease.

3. Base material The base material used in the present invention is made of a resin and is not particularly limited as long as it can hold the first inorganic layer and the second inorganic layer. It is preferable to have properties. This is because the base material needs to withstand the firing step when forming the second inorganic layer.
As the heat resistance of the substrate, it is preferable to realize 80 ° C. or higher, particularly 120 ° C. or higher, particularly 180 ° C. or higher.
Moreover, it is preferable that a linear expansion coefficient is 70 ppm / degrees C or less within the range of 30 degreeC-150 degreeC. When the linear expansion coefficient exceeds the above value, the substrate dimensions are not stable at high temperatures, and the gas barrier performance deteriorates, cracks occur, or peels from the first inorganic layer or the like with thermal expansion and contraction. Because there is a possibility. The linear expansion coefficient is a sample having a width of 5 mm and a length of 20 mm, a constant load (2 g) is applied in the length direction, and the temperature range from 25 to 200 ° C. is increased at a rate of temperature increase of 5 ° C./min. Let us say the amount of dimensional variation measured.

  Moreover, when using the gas barrier film of this invention as packaging materials, such as a foodstuff and a pharmaceutical, it is preferable that a base material is transparent so that the content can be confirmed from the outside. Furthermore, even when the gas barrier film of the present invention is applied to an organic EL display and light is taken out from the substrate side, the substrate is preferably transparent.

  Examples of the resin used for such a substrate include polyarylate resin, polycarbonate resin, crystallized polyethylene terephthalate resin, polyethylene terephthalate resin, polyethylene naphthalate resin, UV curable methacrylic resin, polyether sulfone resin, and polyether ether ketone. Examples thereof include resins, polyetherimide resins, polyphenylene sulfide resins, polyimide resins and the like.

  Examples of the resin used for the substrate include polar polymers having a cycloalkyl skeleton. Specific examples include acrylate compounds or methacrylate compounds having a cycloalkyl skeleton and derivatives thereof. Among them, examples include (meth) acrylate compounds having a cycloalkyl skeleton (meaning acrylate compounds or methacrylate compounds) as shown in JP-A-11-222508 and resin compositions containing derivatives thereof. it can.

  Furthermore, the base material in the present invention includes the above-described resins, for example, cyclic polyolefin resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), poly ( (Meth) acrylic resins, polycarbonate resins, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyamide resins such as various nylons, polyurethane resins, fluorine resins, acetal resins, cellulose resins, polyether sulfones It can be used in combination with two or more types of resin.

  Moreover, it is preferable that the said base material is excellent in solvent resistance and dimensional stability. Thereby, a 1st inorganic layer, a 2nd inorganic layer, etc. can be formed stably on a base material.

  The thickness of the substrate is preferably in the range of 10 μm to 500 μm, more preferably in the range of 50 to 400 μm, and particularly preferably in the range of 100 to 300 μm. This is because if the thickness of the substrate is too thick, the impact resistance is inferior, the winding becomes difficult at the time of winding, and the gas barrier property may be deteriorated. Moreover, if the thickness of the substrate is too thin, the mechanical suitability is poor and the gas barrier property may be lowered.

  Further, in the present invention, it is preferable to use the substrate after cleaning. As the cleaning method, it is preferable to perform ultraviolet light irradiation treatment with oxygen, ozone, etc., plasma treatment, argon sputtering treatment, or the like. This is because moisture and oxygen can be prevented from being adsorbed.

5. Gas barrier film In this invention, the barrier property with respect to water vapor | steam and oxygen can be obtained by providing a 2nd inorganic layer on a 1st inorganic layer. As the gas barrier properties of the gas barrier film of the present invention, the oxygen gas permeability ^1cc / m 2 / day / atm or less, and preferably less inter alia ^{0.5cc / m 2 / day / atm} . The water vapor transmission rate is preferably 1 g / m ² / day or less, particularly preferably 0.5 g / m ² / day or less. This is because high gas barrier properties can be realized when the oxygen gas permeability and the water vapor permeability are in the above-described ranges.
The oxygen gas permeability is a value measured using an oxygen gas permeability measuring apparatus (manufactured by MOCON, OX-TRAN 2/20: trade name) under the conditions of a measurement temperature of 23 ° C. and a humidity of 90% Rh. It is. The water vapor transmission rate is a value measured using a water vapor transmission rate measuring device (manufactured by MOCON, PERMATRAN-W 3/31: trade name) under the conditions of a measurement temperature of 37.8 ° C. and a humidity of 100% Rh. It is.

  The gas barrier film of the present invention can be used, for example, for packaging foods, pharmaceuticals, chemicals, electronic members and the like. The gas barrier film of the present invention can also be used as a gas barrier film for a film liquid crystal display or an organic EL display.

In the present invention, an anchor layer may be formed between the base material and the first inorganic layer. By providing the anchor layer, the adhesion between the base material and the first inorganic layer can be improved. For the anchor layer, for example, polyester resin, isocyanate resin, urethane resin, acrylic resin, ethylene vinyl alcohol resin, vinyl modified resin, epoxy resin, modified styrene resin, modified silicon resin, alkyl titanate, or the like can be used. These may be used alone or in combination of two or more.
Examples of the method for forming the anchor coat layer include roll coat, gravure coat, knife coat, dip coat, and spray coat.

B. Next, a method for producing the gas barrier film of the present invention will be described.
The method for producing a gas barrier film of the present invention includes a first inorganic layer forming step of forming at least one vapor-deposited film on a resin substrate, and ultrafine particles in which ultrafine particles are dispersed in a solvent on the first inorganic layer. And a second inorganic layer forming step of forming a film by applying a dispersion and baking.

  FIG. 5 is a process diagram showing an example of a method for producing a gas barrier film of the present invention. In the present invention, first, a vapor deposition film is formed on the substrate 1 made of resin by vapor deposition to form the first inorganic layer 2 (first inorganic layer forming step, FIG. 5A). Next, an ultrafine particle dispersion liquid 23 in which ultrafine particles are dispersed in a solvent is applied on the first inorganic layer 2 and baked to form the second inorganic layer 3 (second inorganic layer forming step, FIG. 5). (B), (c)).

According to the present invention, even when defects such as pinholes are present in the first inorganic layer, which is a deposited film, the second fine particle dispersion liquid in which ultrafine particles are dispersed in a solvent is applied onto the first inorganic layer. Since the inorganic layer is formed, defects such as pinholes in the first inorganic layer can be closed by the ultrafine particles. Moreover, since the defects such as pinholes in the first inorganic layer can be effectively blocked by the leveling properties by coating, a gas barrier film having excellent gas barrier properties can be obtained.
Furthermore, since the ultrafine particles are densely sintered at a temperature much lower than a general temperature when forming the second inorganic layer, a substrate having a relatively low heat resistance can also be used.
Hereinafter, each process of the manufacturing method of the gas barrier film of this invention is demonstrated.

1. 1st inorganic layer formation process The 1st inorganic layer formation process in this invention is a process of forming at least one vapor deposition film on a base material.
The method for forming the first inorganic layer is not particularly limited as long as it is a vapor deposition method, and may be either a PVD method (physical vapor deposition method) or a CVD method (chemical vapor deposition method). The PVD method is preferably used. The vapor deposition film formed by the PVD method is more likely to cause defects such as pinholes and structural defects in terms of production than the CVD method. However, in the present invention, the ultrafine particles in the second inorganic layer cause pinholes and the like. This is because the defect can be closed and the effect of the present invention is remarkably exhibited. In addition, the PVD method is advantageous in terms of cost compared with the CVD method.
As the PVD method, for example, a general method such as a sputtering method, a vacuum deposition method, or an ion plating method is used. In particular, when a vacuum deposition method or an ion plating method with high productivity is used, the effect of improving the gas barrier property is remarkably exhibited, which is effective.

  In this step, a plurality of vapor deposition films may be stacked to form the first inorganic layer. This is because gas barrier properties can be improved by laminating a plurality of deposited films. In addition, about the lamination | stacking number of a vapor deposition film, it is the same as that of what was described in the term of the 1st inorganic layer of the said "A. gas barrier film".

At this time, it is preferable to stack the deposited film so that there is no pinhole. Specifically, it is preferable to form a lower vapor-deposited film on the substrate, polish the surface of the lower vapor-deposited film, and then form an upper vapor-deposited film thereon. For example, as shown in FIG. 6A, when the vapor deposition film 12a is formed on the substrate 1 made of resin, and the foreign matter 31 is present on the surface of the vapor deposition film 12a, the surface of the vapor deposition film 12 is placed on the sandpaper 32. As shown in FIG. 6B, the foreign material 31 can be removed. Then, as illustrated in FIG. 6C, the gas barrier property of the portion where the foreign material 31 was present can be reinforced by further laminating the vapor deposition film 12b on the vapor deposition film 12a. Next, as illustrated in FIG. 6D, the gas barrier property can be obtained by forming the second inorganic layer 3 on the first inorganic layer 2 including the two deposited films 12 a and 12 b.
In addition, in order to stack the deposited film so that there is no pinhole, in addition to stacking the two deposited films as described above, a plurality of deposited films are further formed on the polished deposited film to form a multilayer structure. May be.

As a polishing method, for example, a method using a sandpaper or the like in which suitable abrasive grains are dispersed and adhered on a sheet, a chemical polishing method or a mechanical polishing method, or chemical mechanical polishing (CMP) using them in combination. Etc. can be used.
The chemical polishing method is performed by supplying an etching liquid as an abrasive to an abrasive member made of a foam such as cloth, non-woven fabric, or polyurethane resin.
The mechanical polishing method uses, for example, cloth, non-woven fabric, or polyurethane resin as a polishing member and impregnates colloidal silica or fine powder of cerium oxide as an abrasive, or uses colloidal silica or cerium oxide as an abrasive. This is performed by supplying a dispersion in which is dispersed.

  In any of the above methods, the polishing is performed by rotating the target object, etc., relatively moving the target object and the polishing member, bringing the polishing member into contact with the vapor deposition film surface, and supplying an abrasive as necessary. However, it is preferable to carry out. Further, it is more preferable to polish until all the foreign matters are removed.

2. Second inorganic layer forming step The second inorganic layer forming step in the present invention is a step of forming a film by applying and baking an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent on the first inorganic layer. is there.
This step can be divided into three modes depending on the type of ultrafine particles. The first aspect uses at least one kind of ultrafine particles selected from the group consisting of inorganic oxides, inorganic nitrides, and inorganic oxynitrides. The inorganic oxides, inorganic nitrides, and inorganic oxynitrides A film formed of at least one kind of ultrafine particles selected from the group consisting of substances is obtained. In the second aspect, ultrafine metal particles are used, and a film formed of ultrafine metal particles whose surface is oxidized is obtained. In the third embodiment, metal ultrafine particles are used, and a film formed of metal ultrafine particles is obtained. Hereinafter, the description will be made separately for each aspect.

(1) First Aspect In this aspect, an ultrafine particle dispersion in which at least one ultrafine particle selected from the group consisting of inorganic oxides, inorganic nitrides, and inorganic oxynitrides is dispersed in a solvent is applied. Baked to form a film. Thereby, a film formed of at least one kind of ultrafine particles selected from the group consisting of inorganic oxides, inorganic nitrides, and inorganic oxynitrides can be obtained.
In the second inorganic layer forming step of this embodiment, the ultrafine particle dispersion preparation step for preparing the ultrafine particle dispersion, the coating step for applying the ultrafine particle dispersion, and the coating film obtained in this coating step are baked. And a firing step. Hereinafter, each step will be described.

(I) Ultrafine particle dispersion preparation step The ultrafine particle dispersion used in this embodiment is a dispersion in which ultrafine particles are individually and uniformly dispersed, and is composed of an inorganic oxide, an inorganic nitride, and an inorganic oxynitride. It is prepared by dispersing at least one kind of ultrafine particles selected from the group consisting of in a solvent.
The ultrafine particles of inorganic oxide, inorganic nitride, and inorganic oxynitride are the same as those described in the above section “A. Gas barrier film”, and thus the description thereof is omitted here.
Here, the average particle diameter of the ultrafine particles used in the ultrafine particle dispersion is a value measured by a laser method. The average particle diameter is generally used to indicate the particle size of the particles, and the laser method is to disperse the particles in a solvent and thin the scattered light obtained by applying a laser beam to the dispersion solvent. This is a method of measuring the average particle size, particle size distribution, etc. by calculation. The average particle size is a value measured using a particle size analyzer Microtrac UPA Model-9230 manufactured by Leeds & Northrup as a particle size measuring device by a laser method.

  The method for producing the ultrafine particles is not particularly limited, and for example, a gas evaporation method, a wet reduction method, a thermal reduction method by spraying an organometallic compound in a high temperature atmosphere, or the like is used.

  In the gas evaporation method, the metal or silicon is evaporated in a gas atmosphere and in the gas phase in which the solvent vapor coexists, and the evaporated metal or silicon is brought into contact with a reaction gas (oxygen, nitrogen, etc.) to make inorganic. In this method, oxides, inorganic nitrides, inorganic oxynitrides and the like are formed, condensed into uniform ultrafine particles, and dispersed in a solvent to obtain a dispersion. In this gas evaporation method, ultrafine particles having a uniform particle size can be obtained. In order to prepare an ultrafine particle dispersion using ultrafine particles obtained by a gas evaporation method as a raw material, substitution may be performed with a solvent used for the ultrafine particle dispersion. Further, a dispersant may be added to increase the dispersion stability of the ultrafine particles. As a result, the ultrafine particles are dispersed individually and uniformly, and a fluid state is maintained.

For example, indium oxide ultrafine particles can also be produced as follows.
An aqueous solution of an indium salt such as indium chloride, indium nitrate, indium sulfate, indium acetate, or indium oxalate is maintained at a predetermined temperature, and the aqueous solution and an alkaline aqueous solution such as an ammonium compound or an alkali metal compound are maintained at the predetermined temperature. Mix and perform a coprecipitation reaction at a predetermined pH for a predetermined time to precipitate a hydroxide. Thereafter, if desired, the precipitate is repeatedly washed with ion-exchanged water, and when the electrical conductivity of the supernatant falls below a predetermined value, the precipitated indium coprecipitated hydroxide is filtered off. Next, this coprecipitated hydroxide cake is baked in the atmosphere at a temperature of 350 to 800 ° C., preferably 500 to 800 ° C. to produce indium oxide ultrafine particles. Since the particles after firing are aggregated, it is preferable to pulverize and loosen the aggregated particles.
In the coprecipitation reaction, the reaction temperature is generally 25 to 70 ° C., the reaction time depends on the reaction temperature, but is generally 30 to 120 minutes, and the pH at the end of the reaction is 5 to 11.

The solvent used in the ultrafine particle dispersion is appropriately selected depending on the ultrafine particles to be used. For example, methanol, ethanol, propanol, isopropyl alcohol, butanol, hexanol, heptanol, octanol, decanol, cyclohexanol, terpineol Alcohols such as ethylene glycol and propylene glycol; ketones such as acetone, methyl ethyl ketone and diethyl ketone; esters such as ethyl acetate, butyl acetate and benzyl acetate; ether alcohols such as methoxyethanol and ethoxyethanol; Ethers such as dioxane and tetrahydrofuran; acid amides such as N, N-dimethylformamide; benzene, toluene, xylene, trimethylbenzene, dodecylben Aromatic hydrocarbons such as hexane; long-chain alkanes such as hexane, heptane, octane, nonane, decane, undecane, tridecane, tetradecane, pentadecane, hexadecane, octadecane, nonadecane, eicosane, trimethylpentane; cyclohexane, cycloheptane, And cyclic alkanes such as cyclooctane; Furthermore, water can also be used.
These may be used alone or as a mixed solvent. For example, it may be a mineral spirit that is a mixture of long-chain alkanes.

  For example, as a solvent used when preparing an ultrafine particle dispersion using indium oxide ultrafine particles obtained by the above-mentioned method, alcohols such as methanol, ethanol, isopropanol, butanol; acetone, methyl ethyl ketone, methyl isobutyl ketone, Ketones such as cyclohexanone, isophorone and 4-hydroxy-4methyl-2pentanone; hydrocarbons such as toluene, xylene, hexane and cyclohexane; amides such as N, N-dimethylformamide and N, N-dimethylacetamide; And alkyl ethers such as carbitol and butyl carbitol; sulfoxides such as dimethyl sulfoxide; and the like. These solvents can be used alone or in combination of two or more.

Furthermore, it is preferable that the solvent evaporates during drying and baking performed after applying an ultrafine particle dispersion described later. In particular, the boiling point of the solvent is preferably 120 ° C or higher, more preferably 150 ° C or higher, further preferably 170 ° C or higher, and most preferably 190 ° C or higher. This is because if the boiling point of the solvent is lower than the above range, for example, it is easy to evaporate at the time of drying, so that the ultrafine particles are likely to aggregate and a uniform film may not be obtained. On the other hand, the upper limit of the boiling point of the solvent is about 350 ° C. from the upper limit of the firing temperature.
Among these solvents, terpineol, decane, dodecane, tridecane, tetradecane, dodecylbenzene, mineral spirit, and the like are preferably used.

  What is necessary is just to select the usage-amount of the said solvent suitably according to the ultrafine particle to be used so that it can apply | coat easily and a desired film thickness can be obtained. Specifically, the concentration of the ultrafine particles in the ultrafine particle dispersion is preferably in the range of 1 to 50 wt%, more preferably in the range of 10 to 40 wt%. This is because if the concentration of the ultrafine particles is less than the above range, it is difficult to close defects such as pinholes in the first inorganic layer, and a desired film thickness may not be obtained. On the other hand, when the concentration of the ultrafine particles exceeds the above range, the viscosity of the ultrafine particle dispersion is increased and the fluidity is lowered. This is because the flatness of the surface of the second inorganic layer may be impaired.

  Further, the viscosity of the ultrafine particle dispersion is preferably 100 cP or less at 20 ° C., and more preferably 10 cP or less. This is because when the viscosity is in the above range, defects such as pinholes in the first inorganic layer can be blocked and a flat film can be formed.

(Ii) Applying step In this embodiment, next, the ultrafine particle dispersion is applied to form a coating film.
The method for applying the ultrafine particle dispersion may be any method that can block defects such as pinholes in the first inorganic layer and can be applied to a uniform thickness. For example, spin coating, spray coating, dip coating, etc. Method, roll coating method, ink jet method, screen printing method and the like.

  After the ultrafine particle dispersion is applied to form a coating film, the coating film may be dried to remove the solvent. The drying temperature is appropriately selected according to the type of solvent, but is usually about 50 ° C to 100 ° C.

(Iii) Firing step In the present embodiment, the coating film is then fired.
The firing temperature is appropriately selected depending on the type of ultrafine particles to be used, but is preferably about 150 ° C to 350 ° C, more preferably in the range of 150 ° C to 250 ° C, and still more preferably. It is in the range of 150 ° C to 220 ° C. This is because if the firing temperature is too low, the ultrafine particles may not be sufficiently sintered, and if the firing temperature is too high, the substrate or the like may be thermally damaged. The temperature required to sinter the inorganic oxide constituting the ultrafine particles alone is generally about 400 to 700 ° C., but in the present invention, it is extremely low as 150 ° C. to 350 ° C. due to the size effect of the ultrafine particles. It can be fired at temperature.
Also, the firing time is appropriately selected depending on the type of ultrafine particles used and the like, but is usually about 10 minutes to 1 hour, preferably 15 minutes to 30 minutes.

  In this step, baking may be performed in an oxidizing atmosphere, or baking may be performed in an atmosphere in which ultrafine particles are not oxidized, and then baking may be performed in an oxidizing atmosphere. That is, it may be fired by a one-stage process or may be fired by a two-stage process. This is because the firing by the two-stage process can avoid that only the surface of the ultrafine particles is further oxidized and the sintering becomes insufficient. In addition, since the baking is performed in two stages, a denser film can be formed by low-temperature baking.

Examples of the atmosphere in which the ultrafine particles are not oxidized include a vacuum atmosphere, an inert gas atmosphere, and a reducing atmosphere.
Examples of the inert gas atmosphere include inert atmospheres such as rare gas, carbon dioxide, and nitrogen.
Examples of the reducing atmosphere include hydrogen, carbon monoxide, lower alcohol, and the like. Examples of the lower alcohol include lower alcohols having 1 to 6 carbon atoms such as methanol, ethanol, propanol, butanol, hexanol and the like.
The vacuum atmosphere is, for example, an inert gas such as a rare gas, carbon dioxide, or nitrogen; an oxidizing gas such as oxygen or water vapor; a reducing gas such as hydrogen, carbon monoxide, or a lower alcohol; or the above inert gas and an oxidizing gas. Or a mixed gas with a reducing gas or a reducing gas. When an oxidizing gas is introduced in a vacuum atmosphere, there is an effect that only the organic compound (solvent or dispersant) adhering to the ultrafine particles is burned without oxidizing the ultrafine particles. The vacuum state may be simply drawn by a pump, or once pumped, an inert gas, a reducing gas, or an oxidizing gas may be introduced. Firing in a vacuum atmosphere can usually be performed at about 10 ⁻⁵ to 10 ³ Pa.

  The oxidizing atmosphere may contain oxygen, water vapor, oxygen-containing gas (for example, air), water vapor-containing gas, and the like.

  In this embodiment, the coating film may be dried after firing in an atmosphere in which the ultrafine particles are not oxidized and before firing in an oxidizing atmosphere. This is because the solvent and the dispersant can be removed. The removal of the solvent and the dispersant may be performed at the time of firing.

Further, after firing in an oxidizing atmosphere, firing may be performed in a reducing atmosphere.
Furthermore, ultraviolet irradiation may be performed during firing. More effective in terms of time reduction and low temperature. In the firing, so-called plasma sintering using atmospheric pressure plasma or the like can also be used.

(2) Second Aspect In this aspect, an ultrafine particle dispersion containing ultrafine metal particles is applied and baked to form a film. As a result, a film formed of ultrafine metal particles whose surface is oxidized can be obtained. In this embodiment, since oxidation and sintering proceed simultaneously during firing, a film formed of ultrafine metal particles whose surface is oxidized is formed.
In the second inorganic layer forming step of this embodiment, the ultrafine particle dispersion preparation step for preparing the ultrafine particle dispersion, the coating step for applying the ultrafine particle dispersion, and the coating film obtained in this coating step are baked. And a firing step. In addition, since it is the same as that of what was described in the said 1st aspect about the application | coating process and a baking process, description here is abbreviate | omitted. Hereinafter, the ultrafine particle dispersion preparation process will be described.

(I) Ultrafine particle dispersion preparation step The ultrafine particle dispersion used in this embodiment is prepared by dispersing ultrafine particles of metal in a solvent in which ultrafine particles are dispersed individually and uniformly. .
The ultrafine metal particles are the same as those described in the above section “A. Gas barrier film”, and thus the description thereof is omitted here.

  The method for producing the ultrafine particles is not particularly limited, and for example, a gas evaporation method, a wet reduction method, a thermal reduction method by spraying an organometallic compound in a high temperature atmosphere, or the like is used. The surface of the obtained ultrafine particles is preferably in a metal state, but may be partially oxidized.

The gas evaporation method is a method in which a metal is evaporated in a gas atmosphere in a gas phase in which a solvent vapor coexists, and the evaporated metal is condensed into uniform ultrafine particles and dispersed in a solvent to obtain a dispersion. is there. In this gas evaporation method, ultrafine metal particles having a uniform particle size can be obtained. In order to prepare an ultrafine particle dispersion using the ultrafine metal particles obtained by the gas evaporation method as a raw material, substitution may be performed with a solvent used for the ultrafine particle dispersion. Further, a dispersant may be added to increase the dispersion stability of the ultrafine particles. As a result, the ultrafine particles are dispersed individually and uniformly, and a fluid state is maintained.
Note that a method for producing ultrafine particles by the gas evaporation method is detailed in Japanese Patent No. 2651537 and Japanese Patent Application Laid-Open No. 2005-183054.

Further, as a method for producing ultrafine particles, a chemical reduction method such as a liquid phase reduction method can be used. In this case, a reducing raw material that is a metal-containing organic compound can be used as a raw material for producing ultrafine particles.
The chemical reduction method is a method of preparing an ultrafine particle dispersion by a chemical reaction using a reducing agent. In the case of the fine particles produced by this chemical reduction method, the particle size can be arbitrarily adjusted. In the chemical reduction method, first, the raw material is thermally decomposed at a predetermined temperature in a state where a dispersant is added to the raw material, or ultrafine metal particles are formed using a reducing agent such as hydrogen or sodium borohydride. generate. Next, almost all of the generated ultrafine metal particles are recovered in an independently dispersed state. By replacing the obtained dispersion with a solvent used for the ultrafine particle dispersion, a desired ultrafine particle dispersion can be obtained. The obtained ultrafine particle dispersion maintains a stable dispersion state even if it is concentrated by heating in vacuum.
Note that a method for producing ultrafine particles by a chemical reduction method is detailed in JP-A-2005-81501.

  The solvent used in the ultrafine particle dispersion, the concentration and viscosity of the ultrafine particle dispersion, and the like are the same as those described in the first aspect, and thus the description thereof is omitted here.

(3) Third Aspect In this aspect, an ultrafine particle dispersion containing ultrafine metal particles is applied and baked to form a film. As a result, a film formed of ultrafine metal particles can be obtained.
In the second inorganic layer forming step of this embodiment, the ultrafine particle dispersion preparation step for preparing the ultrafine particle dispersion, the coating step for applying the ultrafine particle dispersion, and the coating film obtained in this coating step are baked. And a firing step. The application process is the same as that described in the first aspect, and the ultrafine particle dispersion preparation process is the same as that described in the second aspect. . Hereinafter, the firing process will be described.

(I) Firing step In this embodiment, since a film formed of ultrafine metal particles is formed, firing is performed in an atmosphere in which the ultrafine particles are not oxidized. Note that the atmosphere in which the ultrafine particles are not oxidized is the same as that described in the first aspect, and thus the description thereof is omitted here.
Further, the firing temperature and firing time are the same as in the first embodiment, and the description thereof is omitted here.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

Hereinafter, the present invention will be specifically described using examples and comparative examples.
[Example]
(Formation of the first inorganic layer)
A fluororesin film (trade name: NEOFLON FEP, thickness: 100 μm) manufactured by DAIKIN was prepared as a transparent substrate. This transparent substrate was washed according to a conventional method.
A silicon oxide film was formed twice on the transparent substrate by sputtering under the following conditions to form a first inorganic layer having a thickness of 200 nm. During each film forming process, lapping polishing was performed while spraying pure water using a polishing tape of about # 800. Subsequently, mirror polishing (polishing) was performed on the lower silicon oxide film while spraying an alumina fine particle abrasive using a rotary polishing machine (manufactured by Speed Fam).
Film formation conditions for silicon oxide film, RF sputtering power: 50 W / cm ² , frequency 13.56 MHz
・ Deposition rate: 10 nm / min ・ Deposition pressure: 0.5 Pa
SiO ₂ target: 4N (density 2.25 g / cm ³ )

(Formation of second inorganic layer)
When producing In particles by gas evaporation using high frequency induction heating under the condition of helium gas pressure of 0.5 torr, the production of In particles is 20: 1 (capacity ratio) of α-terpineol and dodecylamine. Steam was collected, cooled and collected to collect In fine particles, and a dispersion containing 20% by weight of In fine particles having an average particle diameter of 10 nm dispersed in an α-terpineol solvent in an independent state was prepared. Five volumes of acetone were added to 1 volume of this dispersion (colloidal solution) and stirred. The fine particles in the dispersion liquid settled by the action of polar acetone. After standing for 2 hours, the supernatant was removed, the same amount of acetone was added again and stirred, and after standing for 2 hours, the supernatant was removed. From this sediment, the residual solvent was completely removed, In fine particles having an average particle diameter of 10 nm were produced, and confirmed to be non-oxidized fine particles by X-ray diffraction. The fine particles were dispersed in tetradecane at a concentration of 10 wt% to obtain an ultrafine particle dispersion.
This ultrafine particle dispersion was applied onto the first inorganic layer by spin coating. Then, the coating film was baked under conditions of 230 ° C. and 10 minutes under a reduced pressure of 1 × 10 ⁻³ Pa. Next, firing was performed at 230 ° C. for 60 minutes in an oxidizing atmosphere (atmosphere). The film thickness at this time was 200 nm. As a result of observing a pinhole having a size of 1 μm or more in a 5 cm ² region with an optical micrograph (magnification = 1000 times), the second inorganic layer thus formed was not detected.

[Comparative example]
Under the film formation conditions of the first inorganic layer of the example, a silicon oxide film was formed twice on the transparent substrate by a sputtering method to form an inorganic layer (thickness 300 nm). Between each film-forming process, it grind | polished like the Example. Regarding the inorganic layer thus formed, the number of pinholes having a size of 1 μm or more in a 5 cm ² region was counted with an optical micrograph (magnification = 1000 times), and the result was the same as in the example.

[Evaluation]
About the transparent base material and the gas barrier film of the Example and the comparative example, the oxygen transmission rate and the water vapor transmission rate were measured by the method mentioned above.
In the case of a fluorine resin film (trade name: NEOFLON FEP, thickness: 100 μm) made by DAIKIN alone, the oxygen permeability was 300 cc / m ² / day / atm, and the water vapor permeability was 0.7 g / m ² / day. Moreover, in the gas barrier film of the comparative example, the oxygen transmission rate was 12 cc / m ² / day / atm and the water vapor transmission rate was 0.12 g / m ² / day. On the other hand, in the gas barrier film of the example, the oxygen permeability was 1.1 cc / m ² / day / atm and the water vapor permeability was 0.01 g / m ² / day, and high gas barrier properties were obtained.

It is a schematic sectional drawing which shows an example of the gas barrier film of this invention. It is a SEM photograph of the film | membrane formed with the ultrafine particle. It is a SEM photograph of a vapor deposition film. It is a schematic sectional drawing which shows the other example of the gas barrier film of this invention. It is process drawing which shows an example of the manufacturing method of the gas barrier film of this invention. It is process drawing which shows the other example of the manufacturing method of the gas barrier film of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base material which consists of resin 2 ... 1st inorganic layer 3 ... 2nd inorganic layer 10 ... Gas barrier film 12a, 12b ... Deposition film 23 ... Ultrafine particle dispersion

Claims (8)

A base material made of resin, a first inorganic layer that is formed on the base material and is a vapor-deposited film, and a second inorganic layer that is a film formed on the first inorganic layer and made of ultrafine particles. A gas barrier film having
The gas barrier film , wherein the ultrafine particles are at least one ultrafine particle selected from the group consisting of indium oxide, silicon oxide, silicon nitride, and silicon oxynitride .   The gas barrier film according to claim 1, wherein the first inorganic layer includes a plurality of vapor deposition films.   The gas barrier film according to claim 1 or 2, wherein a sintering temperature of the ultrafine particles is 350 ° C or lower. The gas barrier film according to any one of claims 1 to 3, wherein an average particle diameter of the ultrafine particles is within a range of 0.5 nm to 100 nm. A first inorganic layer forming step of forming at least one vapor-deposited film on a resin substrate; and applying and baking an ultrafine particle dispersion in which ultrafine particles are dispersed in a solvent on the first inorganic layer; A method for producing a gas barrier film having a second inorganic layer forming step of forming a film,
The method for producing a gas barrier film, wherein the ultrafine particles are at least one kind of ultrafine particles selected from the group consisting of indium oxide, silicon oxide, silicon nitride, and silicon oxynitride 6. The method for producing a gas barrier film according to claim 5 , wherein, in the second inorganic layer forming step, baking is performed in an atmosphere in which the ultrafine particles are not oxidized, and thereafter baking is performed in an oxidizing atmosphere. In the first inorganic layer forming step, after forming a lower vapor deposition film on the substrate and polishing the lower vapor deposition film surface, forming an upper vapor deposition film on the lower vapor deposition film The method for producing a gas barrier film according to claim 5, wherein the gas barrier film is produced. The method for producing a gas barrier film according to any one of claims 5 to 7, wherein the boiling point of the solvent is 120 ° C or higher.

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