JP2014083689A - Barrier film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel and improved barrier film which can improve its barrier performance compared with the conventional barrier films.SOLUTION: A barrier film 1 includes, on a resin film 2, an alternate lamination part 8 made by alternate lamination of an inorganic plate particles layer 3 including charged inorganic plate particles, and a binder layer 5 bearing charges opposite to the inorganic plate particles and having a layer thickness of 0.4nm or less.

Description

  The present invention relates to a barrier film.

  As a flexible substrate for an electronic device, a barrier film in which a barrier layer is formed on a resin film is used. Conventionally, these barrier films have been used for packaging foods, but have recently been used in electronic devices. For this reason, a dramatic improvement in barrier performance against gas molecules such as moisture and oxygen has been demanded.

  Patent Document 1 discloses such a barrier film. The barrier film described in Patent Document 1 is obtained by laminating a clay layer made of clay particles and a binder layer by an alternate adsorption method.

US Patent Application Publication No. 2004/053037 JP 2011-131450 A

  However, in the barrier film described in Patent Document 1, since the layer thickness of the binder layer is large, gas molecules easily pass through the binder layer. That is, the barrier property of the binder layer was low. For this reason, the barrier performance of the barrier film itself did not satisfy the required level.

  As a method of solving this problem, a method of increasing the number of laminated clay layers is also conceivable, but this method complicates the process and increases the thickness of the barrier film.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a new and improved barrier film capable of improving the barrier performance as compared with the prior art. It is in.

  In order to solve the above problems, according to one aspect of the present invention, a resin film is charged with an inorganic plate-like particle layer containing charged inorganic plate-like particles, and with a charge opposite to that of the inorganic plate-like particles. There is provided a barrier film, characterized in that it has alternating laminated portions in which binder layers having a thickness of 0.4 nm or less are alternately laminated.

  According to this aspect, since the layer thickness of the binder layer is 0.4 nm or less, gas molecules are difficult to pass through the binder layer. Furthermore, the volume fraction of the inorganic plate-like particles is improved. Thereby, the barrier property of a barrier film improves.

  Here, the layer thickness of the binder layer may be set to 0.4 nm or less by the densification process.

According to this viewpoint, gas molecules are less likely to pass through the binder layer. Thereby, the barrier property of a barrier film improves.

  Further, the binder layer may be formed by polycondensing monomers that are polycondensable with each other.

  According to this aspect, since the binder layer is formed by condensation polymerization (condensation) of monomers that can be polycondensed with each other, gas molecules are less likely to pass through the binder layer. Thereby, the barrier property of a barrier film improves.

  Further, the binder layer may be formed by polycondensing a metal alkoxide compound represented by the following chemical formula (1).

  In formula (1), M is a metal atom, X is a functional group, R is an alkyl group, and n and m are integers of 0 or more.

  According to this viewpoint, gas molecules are less likely to pass through the binder layer. Thereby, the barrier property of the barrier film 1 is improved.

  Further, the metal alkoxide compound may be an alkoxysilane compound represented by the following chemical formula (2).

  In formula (1), X is a functional group, R is an alkyl group, and n is an integer of 0 or more and less than 4.

  According to this viewpoint, gas molecules are less likely to pass through the binder layer. Thereby, the barrier property of a barrier film improves.

  Moreover, you may provide the adsorption layer formed between the resin film and the alternating lamination part.

  According to this viewpoint, the volume fraction of the inorganic plate-like particles is improved, and as a result, the barrier property of the barrier film is improved.

  Moreover, you may provide the smoothing layer formed on the alternately laminated part.

  According to this viewpoint, when the barrier film is used as a substrate such as a light emitting element or an OLED, the characteristics of these elements can be improved.

  According to another aspect of the present invention, an inorganic plate-like particle layer containing charged inorganic plate-like particles and an untreated binder layer containing binder particles charged to the opposite charge to the inorganic plate-like particles are formed on a resin film. A method for producing a barrier film, comprising: alternately laminating and generating a binder layer having a thickness of 0.4 nm or less by subjecting an untreated binder layer to a densification treatment Is provided.

  According to this aspect, since the layer thickness of the binder layer is 0.4 nm or less, gas molecules are difficult to pass through the binder layer. Furthermore, the volume fraction of the inorganic plate-like particles is improved. Thereby, the barrier property of a barrier film improves.

  As described above, according to the present invention, since the thickness of the binder layer is 0.4 nm or less, gas molecules are difficult to pass through the binder layer. Furthermore, the volume fraction of the inorganic plate-like particles is improved. Thereby, the barrier property of a barrier film improves.

It is sectional drawing which shows the barrier film which concerns on embodiment of this invention. It is sectional drawing which shows the manufacturing method of the barrier film concerning the embodiment. It is sectional drawing which shows the modification of a barrier film. It is sectional drawing which shows a mode that a gas molecule permeate | transmits the conventional barrier film.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

(Problems of conventional barrier films)
The inventor has scrutinized the conventional barrier film and its problems, and has completed the barrier film according to the present embodiment based on this result. First, the conventional barrier film and its problems will be described.

As a flexible substrate for an electronic device, a barrier film in which a barrier layer is formed on a resin film is used. Conventionally, these barrier films have been used for packaging foods, but in recent years, they have been used in electronic devices, and there has been a demand for dramatic improvement in barrier performance. For example, in the case of an organic electroluminescence device that is an all-solid-state light-emitting device, which is said to be suitable for a flexible display, the required barrier performance is a water vapor transmission rate (WVTR) of 10 −6 (g / M ² / day).

Various companies have proposed barrier films that satisfy such high performance. For example, the US company Vitex discloses a barrier film composed of an alternately laminated structure of a resin film and an alumina layer (http://www.vitexsys.com/barix_how_made.html). According to Vitex, this barrier film has high performance applicable to organic light emitting devices. According to a press release on February 20, 2008 by Mitsubishi Plastics Co., Ltd. (http://www.mpi.co.jp/info/360/index.html), the WVTR is 0.05 (g / m ² / day) barrier film is on the market.

  Many high performance barrier films, including these two technologies, are made using a vacuum process. The vacuum process is generally a process in which a substance constituting the barrier film is attached on a film substrate placed in a vacuum chamber. Since the vacuum process requires a huge vacuum chamber, there is a problem that the capital investment is increased. In addition, since the vacuum process requires an excessive running cost for maintaining the vacuum chamber, there is also a problem that the manufacturing cost of the barrier film increases. Further, the vacuum process has a problem in that the step coverage of the barrier film is poor, and therefore pinholes are likely to occur due to foreign matters on the film substrate.

  On the other hand, a film forming method using a wet process is also known as a method for forming a barrier film. This film forming method can avoid these problems of the vacuum process, and can form a barrier film with few pinholes at low cost. As a wet process, a method using clay particles having almost no gas permeation can be considered. Patent Document 1 discloses a barrier film using clay particles. The barrier film described in Patent Document 1 is obtained by laminating a clay layer made of clay particles and a binder layer by an alternate adsorption method.

  First, the principle that the barrier film disclosed in Patent Document 1 barriers (shields) gas molecules will be described with reference to FIG. FIG. 4 shows a barrier film 100 manufactured by the technique disclosed in Patent Document 1. The barrier film 100 includes a resin film 200 and alternating laminated portions 800. The alternately laminated portion 800 is obtained by alternately laminating the clay layers 300 and the binder layers 500. One unit 600 is constituted by one set of clay layer 300 and binder layer 500. In addition, in the clay layer 300, a defective portion 700 in which clay particles are missing is formed.

  According to such a barrier film 100, gas molecules such as moisture and oxygen cannot pass through the clay particles, and thus advance through the binder layer 500 and the defect portion 700 while bypassing the clay particles in the barrier film. Therefore, the path W through which the gas molecules pass through the barrier film 100 becomes long like a maze, so that the gas molecules are less likely to pass through the barrier film 100. Based on such a principle, the barrier film 100 barriers gas molecules.

  The gas permeability of the barrier film using clay particles is estimated by Journal of Membrane Science, 38 (1988) 161-174 (hereinafter also referred to as “reference literature”).

  According to the reference, the gas permeability of the barrier film (for example, WVTR) is approximately the square of the volume fraction of the clay particles contained in the barrier film and the aspect ratio of the clay particles (size of clay particles / clay particles Is proportional to the square of the square) and proportional to the gas permeability of the binder layer alone. Here, the volume fraction of the clay particles is a value obtained by dividing the total volume of the clay particles by the total volume of the alternately laminated portions. The size (area) of the clay particles means the area of a plane perpendicular to the thickness direction of the clay particles. Hereinafter, the area of the clay particles means an area of a plane perpendicular to the thickness direction of the clay particles.

  Therefore, to lower the gas permeability of the barrier film (increase the barrier performance), select clay particles with a large aspect ratio (ie, flatter) and increase the mixing ratio (volume fraction) of the clay particles. However, it is important to reduce the gas permeability of the binder layer alone. That is, since the binder layer becomes a passage for gas molecules, it is necessary to improve the barrier property of the binder layer (lower the gas permeability) in order to improve the barrier property of the barrier film.

  Therefore, when the barrier film 100 disclosed in Patent Document 1 is studied, the thickness per clay layer is about 2 nm, and the thickness per binder layer is about 20 nm. Thus, the binder layer 500 is very thick. This may be because the binder layer 500 contains a large amount of moisture and the density of the binder layer 500 is low.

  Therefore, the gas molecules easily pass through the binder layer 500. That is, the barrier property of the binder layer 500 was low. Furthermore, the volume fraction of the clay particles was a very small value of about 9%. For this reason, the barrier performance of the barrier film 100 itself did not satisfy the required level.

  As a method of solving this problem, a method of increasing the number of clay layers, that is, the number of units 600 is also conceivable. However, this method requires a very large number of layers, which complicates the process. And a barrier film will become thick. When the barrier film is thick, it becomes difficult to achieve both transparency and transmittance as described later.

  On the other hand, Patent Document 2 also discloses a barrier film using clay particles. In the technique disclosed in Patent Document 2, a clay particle dispersion is applied on a substrate and the solvent is dried to form a clay film having a thickness of 1 to 100 μm. In the clay film, clay particles are stacked in layers, and the distance between the clay particles is 1.3 nm or less. And a barrier film is produced | generated by providing a water vapor | steam barrier layer in the front and back both surfaces of a clay film. In this barrier film, since the distance between the clay particles is 1.3 nm or less, it becomes difficult for moisture to enter between the clay particles. Furthermore, the water vapor barrier layer makes it difficult for moisture to enter the clay film.

  In general, clay particles contain metal ions such as Na as counter ions between the layers. On the other hand, the technique disclosed in Patent Document 2 generates a clay film by applying and drying a clay dispersion on a substrate, so that metal ions remain in the clay film. The remaining metal ions are eluted or precipitated from the clay film in the subsequent process. Therefore, in the technique disclosed in Patent Document 2, there is a possibility that metal ions may damage electronic devices (for example, TFT array substrates) formed on a clay film.

  Furthermore, since the clay film disclosed in Patent Document 2 is as thick as 1 to 100 μm, it is difficult to achieve both transparency and gas permeability. That is, when natural clay (for example, natural montmorillonite) is used to produce the clay film of Patent Document 2, the transparency is remarkably reduced. This is because natural clay contains many impurities. As a method for solving this problem, it is conceivable to use synthetic clay (for example, synthetic montmorillonite). This is because the synthetic clay has a low impurity content, and therefore transparency may be secured even with the film thickness of Patent Document 2. However, this method increases the gas permeability of the clay film. This is because the synthetic clay particles are smaller than the natural clay particles, and the aspect ratio of the particle shape, that is, the size / thickness of the particles, is smaller in the synthetic clay.

  Thus, the techniques disclosed in Patent Documents 1 and 2 have a problem that the gas permeability and transparency cannot be satisfied at the same time. In view of the above problems, the present inventor has developed the barrier film described in the present embodiment. Hereinafter, the barrier film according to the present embodiment will be described.

(Barrier film structure)
Next, the structure of the barrier film according to the present embodiment will be described with reference to FIG. The barrier film 1 according to the present embodiment includes a resin film 2 and alternating laminated portions 8 in which inorganic plate-like particle layers 3 and binder layers 5 are alternately laminated. A unit 6 is constituted by a set of the inorganic plate-like particle layer 3 and the binder layer 5. In the following description, a film manufactured in the course of manufacturing the barrier film 1, that is, the surface of the resin film 2, the inorganic plate-like particle layer 3 and the untreated binder layer 4 (before the densification treatment is performed). A film in which at least one of the binder layers is laminated is also referred to as an “intermediate film”.

(Configuration of resin film)
Next, the structure of the resin film 2 will be described. The resin film 2 may be made of any resin as long as it is a known resin. For example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), and polyimide (PI) ) Etc. The resin film 2 may be composed of only one of these substances, or may be composed of two or more substances among these substances.

The resin film 2 is positively or negatively charged. In FIG. 1, the resin film 2 is positively charged. The treatment for charging the resin film 2 is not particularly limited. For example, physical treatment (for example, corona treatment, UV / O ₃ treatment, etc.), EB treatment (electron beam treatment), and a chemical solution such as a silane coupling agent. Chemical treatment or the like can be used. By corona-treating the surface of the resin film 2, the surface of the resin film 2 is negatively charged. Further, when the surface of the resin film 2 is treated with a silane coupling agent, the surface of the resin film 2 is positively charged.

  Which of the inorganic plate-like particle layer 3 and the binder layer 5 is laminated on the resin film 2 is determined by the electric charge of the resin film 2, the inorganic plate-like particle layer 3, and the binder layer 5. For example, when the surface of the resin film 2 is positive and the inorganic plate-like particle layer 3 is negatively charged, the inorganic plate-like particle layer 3 is laminated on the resin film 2 and the binder layer 5 is made of the inorganic plate-like particle. Laminate on layer 3.

(Configuration of inorganic plate-like particle layer)
Next, the inorganic plate-like particle layer 3 constituting the barrier film 1 will be described. The inorganic plate-like particle layer 3 is composed of inorganic plate-like particles.

  The inorganic plate-like particles include inorganic layered compounds such as mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite and other clay minerals, zirconium phosphate, and layered double hydroxide (LDH). It is obtained by exfoliating.

  These inorganic layered compounds are obtained by laminating a plurality of positively or negatively charged inorganic plate-like particles via counter ions (for example, sodium ions) charged to a charge opposite to that of the inorganic plate-like particles. In order to separate the inorganic layered compound, for example, particles having a particle size larger than the interlayer ions, such as water molecules, calcium ions, and tetrabutylammonium ions may be inserted between the inorganic plate-like particles. For example, the inorganic layered compound may be added to water and stirred.

  The inorganic plate-like particle layer 3 may be composed of one kind of inorganic plate-like particle, or may be composed of two or more kinds of inorganic plate-like particles having the same charge.

  The ease of delamination depends on the charge density of the inorganic layered compound. Examples of the inorganic layered compound that is easily delaminated include montmorillonite and zirconium phosphate. Therefore, it can be said that these inorganic layered compounds are preferable in terms of easy delamination.

  The inorganic plate-like particles have a very flat shape and are composed of an inorganic substance such as a metal oxide. Inorganic plate-like particles hardly permeate gas. Therefore, the barrier performance of the barrier film 1 is improved by arranging the inorganic plate-like particles horizontally with respect to the other layers.

  Regarding the dimensions of the inorganic layered compound, for example, the diameter in the plane direction (direction perpendicular to the thickness direction) is 10 nm to 10 μm, and the thickness is 1 to 100 nm. The diameter in the plane direction is, for example, the value obtained by arithmetically averaging the equivalent diameter of each particle (the diameter when the shape of the particle in the plane direction is a circle), and the thickness is the arithmetic average of the thickness of each particle. Value. The planar diameter and thickness of the inorganic tabular compound particles are measured by, for example, SEM (scanning electron microscope), AFM (atomic force microscope), or laser scattering particle size distribution analyzer.

  Further, the inorganic plate-like particles are charged positively or negatively as described above. Specifically, the inorganic platy particles obtained from clay minerals such as mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite, and zirconium phosphate are negatively charged.

On the other hand, the inorganic plate-like particles obtained from the layered double hydroxide are positively charged. That is, the layered double hydroxide is represented by the following chemical formula 1.
^{_{[M 2+ 1-x M 3+}} x (OH) 2] x + [B n- x / n · yH 2 O] x- ··· ( Formula 1)
In Chemical Formula 1, M ²⁺ is a divalent metal, M ³⁺ is a trivalent metal, B is an anion, n is a valence of the anion, x is a real number where 0 <x <0.4, and y is a real number greater than 0. That is, the layered double hydroxide has a structure similar to that of brucite, an anion and a layer between positively charged inorganic plate-like particles ([M 2 ⁺ _1-x M ³⁺ _x (OH) ₂ ] ^{x +} ). It is an inorganic layered compound composed of interlayer water and in which negatively charged interlayer ions ([B nx _{/ n} · yH ₂ O] ^x− ) are arranged.

Electrical neutrality is maintained in the entire layered double hydroxide crystal. Mg, Mn, Fe, Co, Ni, Cu, Zn and the like are known as the divalent metal, and Al, Fe, Cr, Co, In, Ga and the like are known as the trivalent metal. The anions include OH ⁻ , F ⁻ , Cl ⁻ , NO ₃ ⁻ , SO ₄ ²⁻ , CO ₃ ²⁻ , Fe (CN) ₆ ⁴⁻ , CH ₃ COO ⁻ , V ₁₀ O ₂₈ ⁶⁻ , dodecyl. SO ₄ ^{− and the} like are known.

  The inorganic plate-like particle layer 3 is formed by an adsorption method. The adsorption method is a technique in which a substrate having a charged surface is immersed in a dispersion of particles charged to a charge opposite to that of the substrate. In this method, particles are adsorbed on the substrate surface by Coulomb force. In the present embodiment, the resin film 2 or the intermediate film whose surface becomes the binder layer 5 is immersed in a dispersion of inorganic plate-like particles charged to a charge opposite to the surface charge of the resin film 2 or the intermediate film. Thereby, inorganic plate-like particles are adsorbed on the surface of the resin film 2 or the intermediate film. At this time, the inorganic plate-like particles are adsorbed so as to be parallel to the surface of the resin film 2 or the intermediate film.

  The dispersion of inorganic plate-like particles is produced by adding an inorganic layered compound to water and stirring. Here, the concentration of the inorganic layered compound is preferably 0.01 to 10 (g / L), and more preferably 0.1 to 1 (g / L). When the concentration is too low, the adsorption of the inorganic plate-like particles to the resin film 2 or the intermediate film becomes insufficient. On the other hand, when the concentration is too high, the viscosity of the dispersion becomes high. The dispersion is composed of at least water and an inorganic layered compound (specifically, inorganic plate-like particles and interlayer ions formed by delamination of the inorganic layer-like compound), in order to increase the dispersibility of the inorganic plate-like particles. And an intercalating agent for promoting delamination of the inorganic layered compound.

(Binder layer configuration)
The binder layer 5 is composed of binder particles that can be charged to a charge opposite to that of the inorganic plate-like particle layer 3. Examples of such binder particles include polymer electrolyte ions, metal ions, metal compound ions, metal alkoxides, and inorganic plate particles that can be charged oppositely to the inorganic plate particle layer 3. The binder layer 5 may be composed of only one of these substances, or may be composed of two or more substances having the same charge among these substances. From the viewpoint of barrier performance, the binder layer 5 is preferably made of an inorganic material. Specifically, metal plate, metal compound ion, metal alkoxide, and inorganic plate-like particles that can be charged opposite to the inorganic plate-like particle layer 3 are preferable.

Examples of the polymer electrolyte ions include polymer electrolyte ions in which protons are coordinated to nitrogen atoms of polyallylamine and polyacrylamide. Examples of metal ions include ions such as Al, Mg, K, and polyvalent transition metals. Examples of the polyvalent transition metal include iron, Co, and Mn. Examples of the metal compound ions include metal oxoacids or oxonium ions such as VO ₃ ⁻ , MoO ₄ ²⁻ , WO ₄ ²⁻ , and TiO ₂ ⁺ .

  Examples of the metal alkoxide compound include a compound represented by the following chemical formula (1).

  In formula (1), M is a metal atom, X is a functional group, R is an alkyl group, and n and m are integers of 0 or more. Examples of M include Si, Ge, Sn, Pb, B, Al, Ga, In, Ti, Zr, Hf, and Y. Examples of X include a functional group capable of interacting with the negatively charged inorganic plate-like particle layer 3. Examples of such functional groups include amino groups, ammonium groups, pyridyl groups, pyridinium groups, bipyridyl groups, terpyridyl groups, pyridazine groups, pyrimidine groups, pyrazine groups, triazines, quinoline groups, quinolinium groups, isoquinolinium groups, and isoquinolinium groups. Substituents having a group and a partial structure thereof, substituents having a partial structure in which one or more of these nitrogen atoms are cationic by alkylation, protonation or condensed ring skeleton structure, pyrrole, imidazole, and these parts Examples thereof include a substituent having a structure, and a functional group having a partial structure in which at least one of the nitrogen atoms contained in these five-membered ring skeletons is alkylated, protonated, or has a cationic structure due to a condensed ring skeleton structure.

  On the other hand, as X capable of interacting with the positively charged inorganic plate-like particle layer 3, as well as carboxyl group and carboxylic acid anhydride, sulfonic acid group, selenic acid, telluric acid, phosphoric acid group, phosphorous acid, arsenic acid, Examples include oxo acid groups such as arsenous acid, antimonic acid, molybdic acid, and tungstic acid.

  An alkoxy group composed of OR can be hydrolyzed to a hydroxyl group, and then a hydroxyl group can be dehydrated to form a network having an O-M-O bond. By forming this network, the gas permeability of the binder layer 5 can be further reduced. That is, in this embodiment, the binder layer 5 is densified by hydrolyzing an alkoxy group to make the alkoxy group a hydroxyl group and then condensing the hydroxyl groups.

  The metal alkoxide compound is preferably an alkoxysilane compound represented by the following chemical formula (2).

  In the formula (1), X and R are the same as those in the chemical formula (1), and n is an integer of 0 or more and less than 4. When the metal alkoxide compound is an alkoxysilane compound represented by the chemical formula (2), the above-described network is formed by the densification treatment, so that the gas permeability of the binder layer 5 further decreases.

  Examples of the inorganic plate-like particles include the same materials as the inorganic plate-like particles constituting the inorganic plate-like particle layer 3.

  The binder layer 5 is formed by an adsorption method in the same manner as the inorganic plate-like particle layer 3. In the present embodiment, the resin film 2 or the intermediate film whose surface is the inorganic plate-like particle layer 3 is immersed in a solution (or dispersion) of binder particles charged to a charge opposite to the surface charge of the film substrate or intermediate film. To do. As a result, the binder particles are adsorbed on the surface of the film substrate or the intermediate film. That is, the untreated binder layer 4 is formed on the surface of the film substrate or intermediate film. Here, the untreated binder layer 4 is a binder layer 5 before a densification process described later is performed. The untreated binder layer 4 becomes the binder layer 5 by being subjected to a densification process.

  A solution (or dispersion) of binder particles can be obtained by dissolving or dispersing various compounds (or binder particles) in water or various solvents. Here, the concentration of the compound is preferably 100 (nmol / L) to 1 (mol / L), and more preferably 1 (μmol / L) to 100 (mmol / L). When the concentration is too low, the adsorption of the binder particles to the film substrate or the intermediate film becomes insufficient. On the other hand, when the concentration is too high, the viscosity of the binder particle solution (or dispersion liquid) becomes high.

  The binder particle solution (or dispersion liquid) is composed of at least water or various solvents and binder particles. When the binder particles are inorganic plate particles, a dispersant for increasing the dispersibility of the inorganic plate particles or an inorganic An intercalating agent for promoting layer separation of the layered compound may be included.

When the binder layer 5 is composed of polymer electrolyte ions, examples of the compound include ionic polymers such as polyallylamine hydrochloride and polyacrylic acid. When the binder layer 5 is composed of metal ions, examples of the compound include metal sulfate, sulfite, nitrate, nitrite, phosphate, chloride, bromide, iodide, hydroxide, such as AlK (SO ₄ ) ₂ , AlNH ₄ (SO ₄ ) ₂ , MgCl ₂ , Mg (NO ₃ ) ₂ , KOH, K ₂ SO ₄ , K ₂ SO ₃ , KCl, KBr, KI, FeK (SO ₄ ) ₂ , FeCl ₂ , FeCl ₃ , CoCl ₂ , Co (NO ₃ ) ₂ , MnCl ₂ , Mn (NO ₃ ) ₂ , NiCl ₂ , Ni (NO ₃ ) ₂ , CuCl ₂ , Cu (NO ₃ ) ₂ , ZnCl ₂ , Zn (NO ₃ ) ₂ , CaCl ₂ , Ca (NO ₃ ) ₂ , SrCl ₂ , Sr (NO ₃ ) ₃ , BaCl ₂ , Ba (NO ₃ ) ₂ , SnCl ₂ , Sn (NO ₃ ) ₂ , GaCl ₃ , G Examples include a (NO ₃ ) ₂ , InCl ₃ , In (NO ₃ ) ₃ , Zn (NO ₃ ) ₂ , Zn (NO ₃ ) _{2, and the} like. When the binder layer 5 is composed of metal compound ions, examples of the compound include sodium salts and ammonium salts of oxo acids such as NaVO ₃ , (NH ₄ ) ₂ MoO ₄ , (NH ₄ ) ₂ WO ₄ , TiOSO _{4 and the} like. Is mentioned. When the binder layer 5 is composed of a metal alkoxide compound, examples of the compound include aminopropyltriethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-ureidopropyltriethoxysilane. It is done. In addition to the above silane compounds, magnesium, calcium, strontium, barium, yttrium, titanium, germanium, tin, zirconium, hafnium, vanadium, niobium, tantalum, iron, boron, aluminum, gallium, indium, copper, zinc methoxy, ethoxy Alkoxides such as isopropoxy and butoxy can also be used as a binder.

  The intermediate film on which the resin film 2 or the inorganic plate-like particle layer 3 is formed is immersed in the prepared binder particle solution (or dispersion). The binder particles are adsorbed on the surface of the resin film 2 or the intermediate film by Coulomb force, whereby the untreated binder layer 4 is formed. The untreated binder layer 4 becomes the binder layer 5 by being subjected to a densification process.

  The layer thickness of the binder layer 5 is set to 0.4 nm or less by the above-described densification process. When the layer thickness of the binder layer 5 is 0.4 nm or less, the gas permeability of the binder layer 5 is remarkably lowered, and as a result, the barrier performance of the barrier film 1 is remarkably improved.

(Manufacturing method of barrier film)
Next, the manufacturing method of the barrier film 1 is demonstrated based on FIG. Here, as an example of the manufacturing method, a manufacturing method in which the inorganic plate-like particle layer 3 is laminated on the resin film 2 and then the binder layer 5 is laminated on the inorganic plate-like particle layer 3 will be described. Of course, the binder layer 5 may be laminated.

(First stage: charging treatment to resin film)
First, as shown in FIG. 2A, the surface of the resin film 2 is positively charged. Alternatively, an adsorption layer is formed on the surface of the resin film 2 and the adsorption layer is positively charged. As a method for charging the resin film 2 or the adsorption layer, for example, corona treatment, UV / O ₃ treatment, EB treatment (electron beam treatment), chemical treatment with a chemical solution such as a silane coupling agent, or the like can be used. .

(Second stage: treatment to form inorganic plate-like particle layer)
Next, as shown in FIG. 2B, a negatively charged inorganic plate-like particle layer 3 is formed on the surface of the resin film 2. Specifically, first, at least one of clay mineral and zirconium phosphate is put into water and delamination treatment is performed to generate a dispersion of inorganic plate-like particles. The clay mineral and zirconium phosphate are obtained by laminating negatively charged inorganic plate-like particles via interlayer ions. Next, the resin film 2 is immersed in a dispersion of inorganic plate-like particles. Thereby, inorganic plate-like particles are adsorbed on the surface of the resin film 2. That is, the inorganic plate-like particle layer 3 is formed on the surface of the resin film 2. However, the inorganic plate-like particle layer 3 may be formed with a defective portion 7 that is a portion where the inorganic plate-like particles are missing.

(Third stage: treatment for forming an untreated binder layer)
Next, an untreated binder layer 4 is formed on the inorganic plate-like particle layer 3 as shown in FIG. Specifically, first, an aqueous solution (or dispersion) of binder particles is prepared. The binder particles are positively charged. Next, the intermediate film whose surface is the inorganic plate-like particle layer 3 is immersed in the aqueous binder particle solution (or dispersion). Thereby, binder particles are adsorbed on the surface of the intermediate film. That is, the untreated binder layer 4 is formed on the surface of the intermediate film. At this time, when the binder particles are inorganic plate-like particles, the inorganic plate-like particles are adsorbed so as to be parallel to the surface of the intermediate film.

(Fourth stage: repetitive processing)
Next, as shown in FIG. 2 (d), the inorganic plate-like particle layers 3 and the untreated binder layers 4 are alternately laminated on the resin film 2 by repeatedly performing the second to third steps. To go. Thereby, the alternating lamination part 8 is formed.

(5th stage: Densification process)
Next, a process for densifying the unprocessed binder layer 4, that is, a densification process is performed. Specifically, the thickness of the untreated binder layer 4 is set to 0.4 nm or less by applying energy to the alternately laminated portions 8 formed in the fourth stage, specifically, the untreated binder layer 4. As a result, the unprocessed binder layer 4 becomes the binder layer 5. Therefore, the layer thickness A of the binder layer 5 is 0.4 nm or less.

  Note that the moisture in the untreated binder layer 4 evaporates due to the densification process. Further, when the binder particles are the above-described metal alkoxide, the alkoxy group is hydrolyzed to become a hydroxyl group, and then the hydroxyl group is dehydrated and condensed to form a network having an O-MO bond. To do. Thereby, the layer thickness of the untreated binder layer 4 is reduced. Examples of a method for applying energy to the alternately laminated portions 8 include heating, infrared irradiation, ultraviolet irradiation, electron beam irradiation, plasma irradiation, or a combination of one or more of these. Thereby, the barrier film 1 is manufactured.

(Function of barrier film)
Since the barrier film 1 has the alternately laminated portions 8 in which the inorganic plate-like particle layers 3 and the binder layers 5 are alternately laminated, the gas molecules proceed through the barrier film 1 in the same manner as the barrier film 100 shown in FIG. . That is, the gas molecules travel through the binder layer 5 and the defect portion 7 while bypassing the inorganic plate-like particles in the barrier film. Accordingly, the path through which the gas molecules pass through the barrier film 1 becomes long like a maze, so that the gas molecules are less likely to pass through the barrier film 1. Based on such a principle, the barrier film 1 barriers gas molecules.

  Here, according to the reference, the gas permeability of the barrier film 1 is approximately the square of the volume fraction of the inorganic plate-like particles contained in the barrier film, and the aspect ratio of the inorganic plate-like particles (the size of the clay particles). Thickness / thickness of clay particles) and inversely proportional to the square of the particle, and proportional to the gas permeability of the binder layer alone.

  In the present embodiment, the binder layer 5 is thinned to a thickness of 0.4 nm or less by a densification process. For this reason, the volume fraction of inorganic plate-like particles is increased. Specifically, the binder layer 5 that is a passage of gas molecules has a very thin layer thickness, so that it is difficult for gas molecules to pass through the binder layer 5. Further, the inorganic plate-like particles are composed of particles having a large aspect ratio, such as montmorillonite. Furthermore, the barrier property (gas permeability) of the binder layer 5 is also lowered by the densification process. Therefore, the gas permeability of the barrier film 1 is improved as compared with the conventional case, and as a result, the level required for the barrier film 1 can be satisfied.

  Furthermore, since the inorganic plate-like particle layer 3 is generated by an adsorption method (alternate adsorption method), there are almost no counter ions contained in the inorganic plate-like particle layer 3. Therefore, the possibility that the barrier film 1 damages the electronic device is reduced.

  Furthermore, since the alternating lamination part 8 is produced | generated by the alternating adsorption method, the layer thickness becomes very thin (for example, 0.1 micrometer or less). Therefore, both transparency and gas permeability can be achieved. That is, since the alternately laminated portion 8 has a very thin layer thickness of 0.1 μm or less, transparency is ensured even when the inorganic plate-like particle layer 3 is generated using natural clay having a high gas permeability. The

(Modification of barrier film)
FIG. 3 shows a barrier film 1 a which is a modification of the barrier film 1. The barrier film 1a is obtained by adding an adsorption layer 2a and a smoothing layer 9 to the barrier film 1.

  The adsorption layer 2 a is for adsorbing the resin film 2 to the inorganic plate-like particle layer 3 or the binder layer 5. The material that can be used for the adsorption layer 2a is not particularly limited as long as it is a material that can be charged to a positive charge or a negative charge and is more hydrophilic than the surface of the resin film 2. For example, a metal or a metal compound Or a material in which a small amount of an organic substance is combined with these metals or metal compounds. Specific examples of such inorganic materials include Al, Cr, Co, Ni, Mn, Si, Cu, Ti, Mo, Ta, W, Au, etc., alloys of these metals, or compounds of these metals and alloys. Furthermore, it may be a composite material in which these metals (including alloys) and metal compounds are mixed with an organic substance that does not impair the desired hydrophilicity.

Since these metal oxides have an OH group on the surface in the atmosphere, when the metal oxide is subjected to corona treatment or UV / O ₃ treatment, the surface is strongly and uniformly charged. Similarly, when the surface of the metal oxide is charged with a silane coupling agent, the surface is strongly and uniformly charged as a result of the silane coupling agent adsorbing the OH groups on the surface of the metal oxide.

  Since the adsorption layer 2a can increase the adsorption amount of the inorganic plate-like particles, the volume fraction of the inorganic plate-like particles can be increased, and as a result, the gas barrier performance of the barrier film 1 can be improved. In addition, when the adsorbing layer 2a has a gas barrier property, it is possible to prevent moisture from re-entering into the binder layer 5 having a higher density, and thus the durability of the barrier film 1 can be improved.

  The smoothing layer 9 is provided on the surface of the alternately laminated portion 8. In general, if the surface roughness of a substrate used for a display element such as a display is increased, light is scattered outside the individual pixels (pixels) due to large light scattering, which is not preferable. Therefore, when the barrier film 1 is used as a substrate of a light emitting element, by providing the smoothing layer 9, the surface roughness (outermost surface) of the barrier film 1 can be further reduced, and light scattering is caused. Blur can be suppressed.

  In addition, organic light emitting diodes (OLEDs) have a very thin layer thickness of the order of 100 nm, and it is known that when the surface roughness of the substrate increases, device characteristics such as short circuit between the anode and cathode are adversely affected. It has been. Thus, when the barrier film 1 is used as an OLED substrate, such an adverse effect can be suppressed by providing the smoothing layer 9. As a forming material and a forming method of the smoothing layer 9, the same material as the adsorption layer 2a can be used. Further, the layer thickness of the smoothing layer 9 is preferably about 1 to 10 times the surface roughness of the surface of the alternate laminated film 8. Specifically, the layer thickness of the smoothing layer 9 is preferably 1 nm or more and 500 nm or less, and more preferably 10 nm or more and 200 nm or less.

  Next, examples of the present embodiment will be described. In Examples 1 to 3 and Comparative Examples 1 to 3, the thinning of the binder layer by the densification process will be described. In Examples 4 to 6 and Comparative Examples 4 to 6, improvement of gas permeability by the densification process will be described.

Example 1
In Example 1, the resin film 2 is positively charged, and the negatively charged inorganic plate-like particle layer 3 and the positively charged binder layer 5 are alternately laminated on the resin film 2. In Example 1, montmorillonite was used for the inorganic plate-like particles, and polyallylamine hydrochloride was used as the binder particles.

1) Cleaning of substrate (resin film 2) A silicon wafer substrate (Niraco # 50000452) whose surface was oxidized was immersed in a piranha solution (hydrogen peroxide solution: concentrated sulfuric acid = 1: 1) for 24 hours, and then purified water It was rinsed with and dried with air blow. That is, in Example 1, a silicon wafer substrate was used as the resin film 2.

2) Adjustment of the charging treatment solution A charging treatment solution composed of a 100 mM APTES solution was prepared by mixing and stirring aminopropyltriethoxysilane (hereinafter referred to as “APTES”) and absolute ethanol.

3) Preparation of inorganic plate-like particle dispersion As an inorganic plate-like particle dispersion, 0.1 g of montmorillonite (hereinafter referred to as “MMT”) (Kunimine Industries Kunifil-D36) was placed in 1 L of pure water, and a commercially available stirrer. (As One KNS-T1) was stirred for 1 day. This prepared the clay layer solution which consists of a MMT separation solution. The layer thickness of the MMT particles (inorganic plate-like particles) is 0.96 nm. This layer thickness substantially matches the layer thickness of the inorganic plate-like particle layer. The layer thickness can be confirmed by an ellipsometer (NL-ELP manufactured by Nippon Laser Electronics). The same applies to the following embodiments.

4) Preparation of binder particle solution A 30 mM aqueous solution of polyallylamine hydrochloride (hereinafter referred to as “PAH”) was prepared as a binder particle solution.

5) Charge treatment of resin film 2 The resin film 2 washed in 1) was immersed in the charge treatment solution prepared in 2) at room temperature for 30 minutes, rinsed in order of ethanol and distilled water, and dried by air blow. Thereby, APTES was adsorbed on the silicon wafer surface. That is, the surface of the resin film 2 was positively charged.

6) Formation of inorganic plate-like particle layer The resin film 2 charged in 5) was immersed in the inorganic plate-like particle dispersion prepared in 3) for 15 minutes at room temperature, then rinsed with distilled water and dried by air blow. As a result, inorganic plate-like particles, that is, MMT were adsorbed on the resin film 2. That is, one layer of the inorganic plate-like particle layer 3 was formed on the resin film 2.

7) Untreated binder layer formation The resin film 2 on which the inorganic plate-like particle layer 3 was formed in 6) was immersed in the binder particle solution prepared in 4) at room temperature for 15 minutes, then rinsed with distilled water and dried by air blow. . Thereby, PAH was adsorbed on the surface of the inorganic plate-like particle layer 3. That is, one untreated binder layer 4 was formed on the inorganic plate-like particle layer 3.

8) Alternate adsorption Alternate adsorption was performed by repeating the steps 6) and 7) a total of 10 times. Thereby, the unprocessed alternating lamination part which consists of ten unprocessed units (a pair which consists of the inorganic plate-like particle layer 3 and the unprocessed binder layer 4) was formed. By repeating the steps 1) to 8) four times, four untreated barrier films were produced.

9) Densification treatment The untreated barrier film formed in the step 8) was heated at 87, 169, 252 and 337 ° C. for 30 minutes one by one using a hot plate (PC-400D manufactured by Aswan). . As a result, four barrier films 1 were produced. In Example 1, the moisture in the untreated binder layer 4 was evaporated by the densification process.

10) Layer thickness measurement The thickness per one layer of the binder layer 5 was measured using the ellipsometer (NL-ELP by Nippon Laser Electronics).

(Example 2)
In Example 2, montmorillonite was used as the inorganic plate-like particles, and APTES was used as the binder particles. Specifically, the same treatment as in Example 1 was performed except that Step 4) of Example 1 was performed as follows.

4) Preparation of binder particle solution A binder particle solution made of 100 mM APTES solution was prepared by mixing and stirring APTES and absolute ethanol as a binder particle solution. In Example 2, the moisture of the untreated binder layer 4 was evaporated by the densification treatment, and a network made of -O-Si-O- was formed.

(Example 3)
In Example 3, zirconium phosphate (ZrP) was used for the inorganic plate-like particles, and APTES was used as the binder particles. Specifically, the same treatment as in Example 2 was performed except that Step 3) of Example 2 was performed as follows.

3) Preparation of inorganic plate-like particle dispersion First, 1 g of first rare element chemical α-ZrP was put in 150 mL of pure water, and stirred for 1 day using a commercially available stirrer (KNS-T1 manufactured by ASONE). Delamination of ZrP particles was performed by adding 30 mL of a 150 mM / L aqueous solution of tetrabutylammonium hydroxide (hereinafter also referred to as “TBAHO”) to the stirred liquid in small portions so that the ph of the ZrP liquid does not exceed 9. It was. Thus, an inorganic plate-like particle dispersion liquid composed of a ZrP dispersion aqueous solution was prepared. The layer thickness of ZrP particles (inorganic plate-like particles) is 0.76 nm.

(Example 4)
In Example 4, layered double hydroxide (LDH) was used for the inorganic plate-like particles, and polyacrylic acid (hereinafter referred to as “PAA”) was used as the binder particles. Specifically, steps 3) and 4) of Example 1 are performed as follows, and further, the order of Steps 6) and 7) of Example 1 is reversed, and is exactly the same as Example 1. Processed. That is, in Example 4, the resin film 2 was immersed in the binder particle solution.

3) Preparation of inorganic plate-like particle dispersion M ²⁺ _x M ³⁺ _y (OH) _n CO ₃ .nH ₂ O (M ²⁺ : Mg, M ³⁺ : Al, B: CO ₃ ²⁻ , x = 4.5, A mixed aqueous solution of sodium chloride 1 mol / L, acetic acid 0.01 mol / L, and sodium acetate 0.09 mol / L was added to the layered double hydroxide (LDH) composed of y = 2 and n = 13). Here, the addition amount of the mixed aqueous solution was 20 mL per 20 mg of LDH. Then, by stirring the mixed aqueous solution for 2 days using a commercially available shaker (SH-B type, Terasawa), M ²⁺ _x M ³⁺ _y (OH) _n Cl ₂ .nH ₂ O (M ²⁺ : Mg, M ³⁺ An inorganic plate-like particle dispersion liquid in which LDH composed of: Al, B: CO ₃ ²⁻ , x = 4.5, y = 2, n = 13) was dispersed was prepared. The layer thickness of LDH particles (inorganic plate-like particles) is 0.5 nm.

4) Preparation of binder particle solution A binder particle aqueous solution was prepared by adjusting a 30 mmol / L aqueous solution of polyacrylic acid (PAA).

(Comparative Example 1)
A barrier film was prepared by the same steps as in Example 1 except that the densification treatment (Step 9) of Example 1 was not performed, and the layer thickness was measured.

(Comparative Example 2)
A barrier film was prepared by the same steps as in Example 2 except that the densification treatment (Step 9) in Example 2 was not performed, and the layer thickness was measured.

(Comparative Example 3)
A barrier film was produced by the same steps as in Example 3 except that the densification treatment (Step 9) in Example 3 was not performed, and the layer thickness was measured.

(Comparative Example 4)
A barrier film was prepared by the same steps as in Example 4 except that the densification treatment (Step 9) of Example 4 was not performed, and the layer thickness was measured.
Table 1 shows the measurement results of Examples 1 to 4 and Comparative Examples 1 to 4. In Table 1, the unit of the layer thickness is nm.

  As shown in Table 1, in Examples 1 to 4, the layer thickness of the binder layer 5 is 0.4 nm or less by the densification process, whereas in Comparative Examples 1 to 4, the densification process is performed. Therefore, the thickness of the binder layer is larger than 0.4 nm.

  Furthermore, the volume fraction of the inorganic plate-like particles in Examples 1 to 4 and Comparative Examples 1 to 4 was calculated by the following formula 1. In Equation 1, “layer thickness per set of alternately laminated portions” is the layer thickness of the unit 6 (unit consisting of one set of inorganic plate-like particle layer and binder layer). The layer thickness of the unit 6 was obtained by measuring the layer thickness of the entire alternate laminate portion with an ellipsometer and dividing the measured value by the number of alternate laminates. The results are shown in Table 2. In Table 2, the unit of the volume fraction of the inorganic plate-like particles is (%). As shown in Table 2, the volume fraction of Examples 1-4 is larger than the volume fraction of Comparative Examples 1-4. Thereby, it was confirmed that the volume fraction is improved by the densification process.

(Volume fraction of inorganic plate-like particles)
= (Layer thickness of inorganic plate-like particle layer) / (Layer thickness per set of alternately laminated portions) Formula 1

(Example 5)
In Examples 5 to 8 and Comparative Examples 5 to 8, barrier films similar to those in Examples 1 to 4 and Comparative Examples 1 to 4 were prepared, and the water vapor permeability (WVTR) was measured as the gas permeability of each barrier film. .

  In Example 5, montmorillonite was used as the inorganic plate-like particles, and polyallylamine hydrochloride was used as the binder particles. Specifically, the following step 1) was performed instead of steps 1), 2) and 5) of Example 1, and the water vapor transmission rate was measured instead of the film thickness measurement in step 10). Except for this, the same treatment as in Example 1 was performed.

1) Film substrate cleaning and surface treatment Upilex-125S (0.125 mm thick polyimide (PI) film) manufactured by Ube Industries was washed with a detergent and pure water and dried by air blow. Thereafter, corona treatment was performed under conditions of 100 W and 1 m / s using TEC-4AX manufactured by Kasuga Electric. This introduced a hydroxyl group on the film surface. That is, in Example 4, a polyimide film was used as the resin film 2. Also in Example 5, the surface of the resin film 2 is positively charged.

10) Measurement of water vapor transmission rate The water vapor transmission rate (that is, WVTR) of the barrier film formed in the process of 9) was measured under the condition of 40 ° C-90% RH using a water vapor transmission rate measuring device AQUATRAN manufactured by MOCON. It was measured.

(Example 6)
In Example 6, montmorillonite was used for the inorganic plate-like particles, and APTES was used as the binder particles. Specifically, the same treatment as in Example 5 was performed except that Step 4) of Example 5 was performed as follows.

4) Preparation of binder particle aqueous solution As binder particle aqueous solution, the binder particle aqueous solution which consists of a 100 mM APTES solution was produced by mixing and stirring APTES and absolute ethanol.

(Example 7)
In Example 7, zirconium phosphate was used as the inorganic plate-like particles, and APTES was used as the binder particles. Specifically, the same treatment as in Example 6 was performed except that Step 3) of Example 6 was performed as follows.

3) Preparation of inorganic plate-like particle dispersion First, 1 g of first rare element chemical α-ZrP was put in 150 mL of pure water, and stirred for 1 day using a commercially available stirrer (KNS-T1 manufactured by ASONE). ZrP particles were delaminated by adding 30 mL of a 150 mM / L aqueous solution of tetrabutylammonium hydroxide to the stirred solution in small amounts so that the ph of the ZrP solution did not exceed 9. Thus, an inorganic plate-like particle dispersion liquid composed of a ZrP dispersion liquid was prepared.

(Example 8)
In Example 8, layered double hydroxide (LDH) was used for the inorganic plate-like particles, and polyacrylic acid (PAA) was used as the binder particles. Specifically, steps 3) and 4) of Example 5 are performed as follows, and furthermore, the order of steps 6) and 7) of Example 5 is reversed, and is exactly the same as Example 1. Processed. That is, in Example 8, the resin film 2 was immersed in the binder particle solution.

3) Preparation of inorganic plate-like particle dispersion M ²⁺ _x M ³⁺ _y (OH) _n CO ₃ .nH ₂ O (M ²⁺ : Mg, M ³⁺ : Al, B: CO ₃ ²⁻ , x = 4.5, A layered double hydroxide (LDH) composed of y = 2, n = 13) was added 20 mL of a mixed aqueous solution of 1 mol / L sodium chloride, 0.01 mol / L acetic acid and 0.09 mol / L sodium acetate per 20 mg LDH. commercial shaker (SH-B type, Terasawa) by stirring for 2 days using _{^{a, M 2+ x M 3+ y (}} OH) n Cl 2 · nH 2 O (M 2+: Mg, M 3+: Al, B: An inorganic plate-like particle dispersion liquid in which LDH composed of CO ₃ ²⁻ , x = 4.5, y = 2, n = 13) was dispersed was prepared.

4) Preparation of binder particle solution A binder particle aqueous solution was prepared by adjusting a 30 mmol / L aqueous solution of polyacrylic acid (PAA).

(Comparative Example 5)
A barrier film was produced by the same steps as in Example 5 except that the densification treatment (Step 9) of Example 5 was not performed, and the water vapor transmission rate was measured.

(Comparative Example 6)
A barrier film was produced by the same process as in Example 6 except that the densification treatment (Example 9) of Example 6 was not performed, and the water vapor transmission rate was measured.

(Comparative Example 7)
A barrier film was produced by the same steps as in Example 7 except that the densification treatment (Step 9) of Example 7 was not performed, and the layer thickness was measured.

(Comparative Example 8)
A barrier film was produced by the same steps as in Example 8 except that the densification treatment (Step 9) of Example 8 was not performed, and the layer thickness was measured. Table 3 shows the measurement results of Examples 5 to 8 and Comparative Examples 5 to 8. In Table 3, the unit of WVTR is (g / m ² / day).

  As shown in Table 3, in Examples 5 to 8, it was found that WVTR was clearly improved (numerical value was smaller) than Comparative Examples 5 to 8.

Example 9
Example 9 is an example in which the adsorption layer 2 a and the smoothing layer 9 are formed using perhydropolysilazane (hereinafter referred to as “PHPS”) as an inorganic material. Specifically, the barrier film of Example 9 was produced by the following procedure.

1) Washing of Resin Film 2 Ube Industries Upilex-125S (0.125 mm thick polyimide (PI) film) was prepared as the resin film 2, and the resin film 2 was washed with a detergent and pure water and dried by air blow. .

2) Formation of adsorption layer 2a Next, the resin film washed in 1) was spin-coated with AquaLS NL 100A manufactured by AZ Electronic Materials as PHPS. Next, the PHPS coated on the resin film was cured at 200 ° C. for 1 hour. As a result, a silica film having a thickness of 0.4 μm was formed as the adsorption layer 2a.

3) Adjustment of charging treatment liquid APTES and absolute ethanol were mixed and stirred to prepare a charging treatment liquid composed of a 100 mM APTES solution.

4) Preparation of inorganic plate-like particle dispersion As an MMT, 0.1 g of Kunimine Industries Kunifil-D36 was put into 1 L of pure water. Next, the pure water charged with MMT was stirred for 1 day using a commercially available stirrer (KNS-T1 manufactured by ASONE). In this way, an inorganic plate-like particle dispersion composed of an aqueous MMT solution was prepared.

5) Preparation of binder particle aqueous solution APTES and absolute ethanol were mixed and stirred to prepare a binder particle aqueous solution composed of a 100 mM APTES solution.

6) Charge treatment of resin film 2 The resin film 2 washed in 1) was immersed in the charge treatment solution prepared in 3) at room temperature for 30 minutes. Next, the resin film 2 coated with the charging treatment liquid was rinsed in the order of ethanol and distilled water, and dried by air blow. Thereby, APTES was adsorbed on the surface of the resin film 2. That is, the adsorption layer 2a was positively charged.

7) Formation of inorganic plate-like particle layer The resin film 2 positively charged in 6) was immersed in the inorganic plate-like particle dispersion prepared in 4) at room temperature for 15 minutes. Next, the resin film coated with the inorganic plate-like particle dispersion was rinsed with distilled water and dried by air blow. As a result, inorganic plate-like particles, that is, MMT were adsorbed on the resin film. That is, one layer of the inorganic plate-like particle layer 3 was formed on the resin film 2.

8) Untreated binder layer formation The resin film 2 on which the inorganic plate-like particle layer 3 was formed in 7), that is, the intermediate film was immersed in the binder particle solution prepared in 5) at room temperature for 15 minutes. Subsequently, the intermediate film coated with the binder particle solution was rinsed with distilled water and dried by air blow. Thereby, APTES was adsorbed on the surface of the inorganic plate-like particle layer 3. That is, one untreated binder layer 4 was formed on the inorganic plate-like particle layer 3.

9) Alternate adsorption Alternate adsorption was performed by repeating the steps 7) and 8) a total of 10 times. Thereby, the unprocessed alternating lamination part which consists of ten unprocessed units (a pair which consists of the inorganic plate-like particle layer 3 and the unprocessed binder layer 4) was formed.

10) Densification treatment The untreated barrier film formed in the step 9) was heated at 169 ° C. for 30 minutes using a hot plate (PC-400D manufactured by Aswan). In Example 9, due to the densification treatment, the water of the untreated binder layer 4 was evaporated and a network composed of —O—Si—O— was formed.

11) Formation of smoothing layer Next, the barrier film produced in the process of 10) was spin coated with AquaNL 100A manufactured by AZ Electronic Materials as PHPS. Subsequently, the PHPS coated on the barrier film was cured at 200 ° C. for 1 hour. Thus, a silica film having a thickness of 0.4 μm, that is, a smoothing layer 9 was formed.

12) AFM observation The barrier film in which only the adsorption layer 2a and the alternate laminated portion 8 are formed by performing the steps up to 10), and the adsorption layer 2a, the alternate laminated portion 8 and the smoothing by performing the steps up to 11). About the barrier film in which the layer 9 was formed, AFM observation was performed using SPM-9500 made by Shimadzu Corporation. Thereby, the surface roughness of each film was confirmed. As a result, the surface roughness was 10.2 nm for the barrier film without the smoothing layer and 1.9 nm for the barrier film with the smoothing layer. Thereby, it was confirmed that the surface roughness was improved by the smoothing layer 9.

13) Measurement of water vapor transmission rate The water vapor transmission rate (that is, WVTR) of the barrier film produced in the step 11) was measured under the condition of 40 ° C-90% RH using a water vapor transmission measuring device AQUATRAN manufactured by MOCON. Measured with

(Comparative Example 9)
A barrier film was prepared in the same manner as in Example 9 except that the densification treatment (Step 10) and AFM observation (Step 12) of Example 9 were not performed, and the water vapor transmission rate was measured. Table 4 shows the WVTR measurement results of Example 9 and Comparative Example 9. In Table 4, the unit of WVTR is (g / m ² / day).

  As shown in Table 4, it was found that in Example 9, WVTR was clearly improved (numerical value was smaller) than Comparative Example 9.

  As described above, in this embodiment, since the layer thickness of the binder layer is 0.4 nm or less, the gas molecules are difficult to pass through the binder layer. Furthermore, the volume fraction of the inorganic plate-like particles is improved. Thereby, the barrier property of the barrier film 1 is improved.

  Furthermore, since the barrier film 1 is prepared by an alternate adsorption method, the content of counter ions in the inorganic plate-like particle layer 3 is almost absent. Therefore, the possibility of damaging the electronic device is reduced. Furthermore, since the layer thickness of the alternately laminated portion 8 becomes very thin (for example, 0.1 μm or less), both transparency and gas permeability (barrier property) can be achieved.

  Furthermore, since the layer thickness of the binder layer 5 is set to 0.4 nm or less by the densification process, it is difficult for gas molecules to pass through the binder layer 5. Thereby, the barrier property of the barrier film 1 is improved.

  Furthermore, since the binder layer 5 is formed by condensation polymerization (condensation) of monomers that are mutually condensation-polymerizable, gas molecules are less likely to pass through the binder layer 5. Thereby, the barrier property of the barrier film 1 is improved.

  Furthermore, since the binder layer 5 is formed by polycondensing the metal alkoxide compound represented by the above chemical formula (1), gas molecules are less likely to pass through the binder layer 5. Thereby, the barrier property of the barrier film 1 is improved.

  Furthermore, since the metal alkoxide compound is an alkoxysilane compound represented by the above chemical formula (2), gas molecules are unlikely to pass through the binder layer 5. Thereby, the barrier property of the barrier film 1 is improved.

  Furthermore, since the barrier film 1 includes the adsorption layer 2a formed between the resin film 2 and the alternately laminated portion 8, the volume fraction of the inorganic plate-like particles is improved, and consequently the barrier property of the barrier film 1 is improved. improves.

  Furthermore, since the barrier film 1 is provided with the smoothing layer 9 formed on the alternately laminated part 8, when the barrier film 1 is used as a light emitting element or a board | substrate of OLED, improving the characteristic of these elements. Can do.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  For example, in the embodiment described above, the barrier film in which the resin film 2 is positively charged, the inorganic plate-like particles are negatively charged, and the binder particles are positively charged has been described. good.

DESCRIPTION OF SYMBOLS 1 Barrier film 2 Resin film 2a Adsorption layer 3 Inorganic plate-like particle layer 4 Untreated binder layer 5 Binder layer 6 Unit 7 Defect part 8 Alternating laminated part 9 Smoothing layer

Claims (8)

  An inorganic plate-like particle layer containing charged inorganic plate-like particles and a binder layer charged to the opposite charge to the inorganic plate-like particles and having a layer thickness of 0.4 nm or less are alternately laminated on the resin film. A barrier film characterized by having alternating laminated portions.   The barrier film according to claim 1, wherein the binder layer has a thickness of 0.4 nm or less by densification treatment.   The barrier film according to claim 1, wherein the binder layer is formed by polycondensing monomers that are polycondensable with each other. The barrier film according to claim 3, wherein the binder layer is formed by condensation polymerization of a metal alkoxide compound represented by the following chemical formula (1).

In formula (1), M is a metal atom, X is a functional group, R is an alkyl group, and n and m are integers of 0 or more. The said metal alkoxide compound is an alkoxysilane compound shown by following Chemical formula (2), The barrier film of Claim 4 characterized by the above-mentioned.

In formula (1), X is a functional group, R is an alkyl group, and n is an integer of 0 or more and less than 4.   The barrier film according to claim 1, further comprising an adsorption layer formed between the resin film and the alternately laminated portion.   The barrier film according to claim 1, further comprising a smoothing layer formed on the alternately laminated portion. Alternately laminating an inorganic plate-like particle layer containing charged inorganic plate-like particles and an untreated binder layer containing binder particles charged to a charge opposite to that of the inorganic plate-like particles on the resin film;
Producing a binder layer having a layer thickness of 0.4 nm or less by subjecting the untreated binder layer to a densification treatment, and a method for producing a barrier film.

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