JP2007313891A - Inorganic compound film and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an inorganic compound film having excellent water resistance and also high gas barrier property and transparency. <P>SOLUTION: The method for obtaining the inorganic compound film comprises: applying on the surface of a base, the liquid containing a hydrophobic inorganic layered compound in which such a compound is dispersed in an organic solvent, and drying to form a hydrophobic inorganic layered compound layer 1; applying the liquid containing a hydrophilic inorganic layered compound dispersed in water onto the surface of the above layer 1, and drying to form a hydrophilic inorganic layered compound layer 2; further applying the above hydrophobic compound-containing liquid onto the surface of the layer 2; drying to form one more layer 1; and peeling the whole layered film from the base. Thereby, it is possible to prepare a three-layered inorganic compound film having the hydrophobic inorganic layered compound layers 1, 1 on both sides of the layer 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inorganic compound film containing a layered inorganic compound and a method for producing the same. The present invention also relates to an electronic paper, a substrate, and a gas barrier film that are at least partially composed of the inorganic compound film.

  In recent years, the manufacturing technology of flat panel displays including liquid crystal displays (hereinafter referred to as FPD) has dramatically advanced, and thin displays that cannot be achieved with conventional cathode ray tubes have become a reality. Almost all current FPDs have devices formed on glass substrates, and there are no practical FPDs using substrates other than glass substrates. The reason for this is that the glass substrate has high heat resistance and is suitable for forming a display drive circuit or member that requires high-temperature formation, a low linear expansion coefficient, and stress applied to the drive circuit or member. Gas barrier that can be suppressed, that there is little breakage of wiring and characteristic fluctuation of parts, that it is easy to extract light because it is transparent in the visible light range, and that has high gas barrier properties and prevents entry of oxygen and water vapor from the outside It can be used as a material, and can maintain a high vacuum if necessary.

  However, the glass substrate is not flexible and easily broken. In addition, the weight is heavy, and the deformation of the substrate and the difficulty in handling are problematic. In addition, glass substrates cannot be used for flexible displays such as electronic paper that can be bent, assuming applications such as bending and carrying. Because it has, it is not very suitable for mobile use. From such a point of view, it is desired to put a display substrate and a gas barrier film into practical use having heat resistance, linear expansion coefficient, transparency, gas barrier properties and the like equivalent to glass.

  On the other hand, there are many kinds of layered inorganic compounds represented by clay minerals, many of which are inexpensive, and are inexpensive, harmless to the human body, and have the characteristics of not burning. As the name suggests, layered inorganic compounds are compounds that form layered (plate-like) crystals. Typical examples include layered silica such as smectite group clay and clay minerals typified by mica, magadiite and kenyanite. There are layered double hydroxides such as acid salts and hydrotalcite. In addition, layered transition metal oxyacid salts such as titanium / niobate, hexaniobate, and molybdate, layered phosphate, layered manganese oxide, layered cobalt oxide, and the like are also representative layered inorganic compounds. . Thus, there are various types of layered inorganic compounds having different compositions.

  Among layered inorganic compounds, especially clay minerals are present in large quantities in nature, and are suitably used for various applications in view of being inexpensive and excellent in dispersibility (see, for example, Non-Patent Document 1). One of the methods of using layered inorganic compounds such as clay minerals is a nanocomposite material in which a small amount of layered inorganic compound (generally about 5% by mass or less) is added to a resin. Have been put into practical use (see, for example, Non-Patent Document 2). In such a nanocomposite material, the effect of improving strength, flame retardancy, and gas barrier properties is recognized by the addition of a layered inorganic compound.

  However, in such a nanocomposite material, the ratio of the layered inorganic compound is small and the orientation is not uniform, or the orientation is somewhat uniform by stretching, etc. It was not an improvement. In particular, taking the gas barrier property, which is one of the great effects achieved by adding the layered inorganic compound, the gas transmission rate is several because the movement distance for gas permeation is increased by the addition of the layered inorganic compound. Although there are cases where it is only a fraction, there are almost no cases where the gas barrier property is improved by an order of magnitude or more.

In addition, for the purpose of improving gas barrier properties by increasing the gas travel distance when gas permeates, layered inorganic compounds such as natural montmorillonite and synthetic mica having a large crystal size are often used. In this case, natural montmorillonite is used. It is difficult to obtain a colorless, highly transparent film with a small haze (cloudiness) that can be used for displays, etc., due to the yellow coloring derived from the light and the scattering of light derived from the large crystal size of the synthetic mica. It was. Similarly, when the amount of layered inorganic compound added is small, it is difficult to significantly improve other physical properties other than gas barrier properties, such as heat resistance and dimensional stability during temperature changes, and high heat resistance and dimensional stability. It was difficult to say that the essential characteristics of the layered inorganic compound excellent in the above are fully utilized.
Smectite clay minerals can be dispersed in water close to the nanosheets, which are the structural units of layered inorganic compounds, so that the nanosheets are aligned by spreading the dispersion on a glass plate, allowing to stand, and drying. In this film formation, a fixed orientation sample of the X-ray diffraction method has been adjusted (see Non-Patent Document 3).

  Conventionally, various methods for adjusting, for example, a functional clay thin film have been reported. For example, a method for producing a clay film by forming an aqueous dispersion of a hydrotalcite-based intercalation compound into a film and drying it (see Patent Document 1), a reaction between a layered clay mineral and phosphoric acid or a phosphate group, A method for producing a layered clay mineral thin film in which the bond structure of the layered clay mineral is oriented and fixed by applying a heat treatment that promotes the reaction (see Patent Document 2), containing a complex compound of a smectite clay mineral and a bivalent or higher metal There are many cases including an aqueous composition for film treatment (see Patent Document 3). However, the film-like forms in these patent documents are all formed on some kind of support, have a mechanical strength that can be used as a self-supporting film, and are laminated with highly oriented nanosheets. It was not a layered inorganic compound alignment film.

  Furthermore, there is a report of a transparent film in which the orientation of the layered inorganic compound is uniform and has a self-supporting strength and water resistance. For example, a hydrophobic layered inorganic compound in which inorganic ions of a layered inorganic compound dispersed in water are replaced with organic ions such as organic ammonium salts to improve dispersibility in an organic solvent, and transparent polyimide, There are many reports such as a report on a transparent film having strength and water resistance (see Patent Document 4). However, since the ratio of the layered inorganic compound is small, high gas barrier properties cannot be obtained.

  Under such circumstances, the present inventors made various attempts to produce a clay oriented film, and in the process, a film having a strength that can be used as a self-supporting film in which nanosheets are oriented is obtained by the following method. (See Patent Document 5). That is, the uniform clay dispersion is left to stand horizontally to deposit the nanosheets, and the liquid as the dispersion medium is separated into various solid-liquid separation methods (for example, centrifugation, filtration, vacuum drying, freeze vacuum drying, or heat evaporation method). ), And after forming into a film shape, this is peeled off from the support.

  Moreover, not only clay but also a small amount of additives can be added to the clay dispersion to increase the flexibility and strength of the film, and by using a clay paste with an increased solid ratio of the clay dispersion, It has been found that it can be produced in a short time (see Patent Document 6), and that a transparent film can be produced in the visible light region without coloring by using synthetic clay with less impurities (see Patent Document 7). It was.

  These films have (1) high heat resistance, (2) high gas barrier properties against inorganic gases such as oxygen and hydrogen, (3) no pinholes in the film, and (4) flexibility. (5) Chemical resistance, (6) Low coefficient of linear expansion, (7) Flame retardant, (8) Insulating properties, etc. The present invention has been found to be suitable for use in electronic materials such as the aforementioned display member.

  In particular, the high gas barrier properties of these films are conspicuous, and it has been found that extremely high gas barrier properties that cannot be explained by the extension of the gas moving distance when the conventional gas permeates are found. As a result of detailed research, it was found that the high gas barrier property is manifested by the fact that nanosheets are stacked very densely, and the occurrence of defects inside the film is suppressed by an additive added in a small amount. It was. A similar phenomenon has been reported by other researchers in recent years (see Patent Document 8).

JP-A-6-95290 JP-A-5-254824 JP 2002-30255 A JP 2006-37079 A JP 2005-104133 A JP 2006-265088 A JP 2007-63118 A JP 2006-167679 A Edited by Sudo Kodankai, “Invitation to Clay Science: Clay's Face and Charm”, Sankyo Publishing, p. 6 (2000) Nakasumi, edited by “Development of Polymer Nanocomposites”, Frontier Publishing, p. 25-90 (2004) Haruo Shiramizu, “Clay Mineralogy-Basics of Clay Science”, Asakura Shoten, p. 57 (1988)

However, a transparent film composed of a conventional layered inorganic compound using a synthetic clay and a small amount of additive exhibits high gas barrier properties as described above, but haze increases when left in the air, and the film In some cases, the transparency was reduced due to cloudiness. In addition, hydrophilic smectite clay and water-soluble resin, which have a high affinity for water and are easy to disperse in water, were used, so the water resistance of the film was insufficient, and the film swelled even with a little water adhering to it. In addition, the layered inorganic compound constituting the film may be dispersed in water with time to cause defects in the film. That is, there has not yet been reported a transparent inorganic compound film having high gas barrier properties, water resistance, and dimensional stability, and having a self-supporting strength.
Therefore, the present invention aims to solve the problems of the conventional inorganic compound film as described above, and to provide an inorganic compound film having excellent water resistance and high gas barrier properties and transparency, and a method for producing the same. To do. Another object is to provide an electronic paper, a substrate, and a gas barrier film provided with such an inorganic compound film.

  In order to solve the above problems, the present invention has the following configuration. That is, the inorganic compound film according to the first aspect of the present invention is an inorganic compound film in which two or more layered inorganic compound layers having a structure in which a large number of layered inorganic compound particles are oriented and laminated are laminated. A hydrophobic layered inorganic compound layer composed of only the hydrophobic layered inorganic compound or the hydrophobic layered inorganic compound and an additive, which has a high affinity for water and is easily dispersed in an organic solvent, and has a high affinity for water and is dispersed in water. The hydrophilic layered inorganic compound layer composed of only the hydrophilic layered inorganic compound or the hydrophilic layered inorganic compound and an additive is easily laminated and has mechanical strength that can be used as a self-supporting film and 80 % Total light transmittance.

The inorganic compound film according to claim 2 of the present invention is the inorganic compound film according to claim 1, wherein the hydrophobic layered inorganic compound and the hydrophilic layered inorganic compound are composed of a clay mineral obtained by synthesis. It is characterized by that.
Furthermore, an inorganic compound film according to a third aspect of the present invention is characterized in that the inorganic compound film according to the first or second aspect has a gas barrier property.
Furthermore, the inorganic compound film of Claim 4 which concerns on this invention is an inorganic compound film | membrane as described in any one of Claims 1-3, The said hydrophobic layered inorganic on the both upper and lower surfaces of the said hydrophilic layered inorganic compound layer. It has a three-layer structure in which compound layers are arranged.

Furthermore, the inorganic compound film of Claim 5 which concerns on this invention is an inorganic compound film as described in any one of Claims 1-3. WHEREIN: The said whole hydrophilic layered inorganic compound layer is the said hydrophobic layered inorganic compound layer. It is characterized by having a structure wrapped in.
Furthermore, the inorganic compound film of Claim 6 which concerns on this invention is a inorganic compound film as described in any one of Claims 1-5, A haze is 5% or less, It is characterized by the above-mentioned.
Furthermore, the inorganic compound film according to claim 7 of the present invention is the inorganic compound film according to any one of claims 1 to 6, wherein the light transmittance in a wavelength range of 400 nm to 800 nm is 80% to 95%. It is characterized by the following.

  Furthermore, the manufacturing method of the inorganic compound film | membrane of Claim 8 which concerns on this invention is an inorganic compound film | membrane as described in any one of Claims 1-7, The said hydrophobic layered inorganic compound layer and the said hydrophilic layered inorganic compound A method for producing by alternately forming layers and laminating, wherein the hydrophobic layered inorganic compound-containing liquid containing the hydrophobic layered inorganic compound or the hydrophilic layered inorganic compound containing the hydrophilic layered inorganic compound After the first step of forming the hydrophobic layered inorganic compound layer or the hydrophilic layered inorganic compound layer on the base is performed by placing the liquid on the base and drying, the hydrophobic layered inorganic compound-containing liquid Alternatively, the hydrophilic layered inorganic compound-containing liquid is disposed on the lower layered inorganic compound layer and dried, whereby a layered inorganic compound layer of a type different from the lower layered inorganic compound layer is converted into the lower layered layered inorganic compound layer And carrying out at least once a second step of forming on the object layer.

Furthermore, the manufacturing method of the inorganic compound film of Claim 9 which concerns on this invention is a manufacturing method of the inorganic compound film of Claim 8, Before performing said 2nd process, on said base by said 1st process. The formed layered inorganic compound layer is peeled from the base, and the second step is performed at least once on the upper and lower surfaces or one surface of the separated layered inorganic compound layer.
Furthermore, the manufacturing method of the inorganic compound film | membrane of Claim 10 which concerns on this invention is the manufacturing method of the inorganic compound film | membrane of Claim 8 or Claim 9, The said hydrophobic layered inorganic compound containing used in said 2nd process The liquid or the hydrophilic layered inorganic compound-containing liquid is characterized in that the layered inorganic compound constituting the lower layered inorganic compound layer does not disperse.

  Furthermore, the manufacturing method of the inorganic compound film | membrane of Claim 11 which concerns on this invention is a method of manufacturing the inorganic compound film | membrane as described in any one of Claim 1,2,3,5, Comprising: Said hydrophobic layer shape A hydrophobic layered inorganic compound-containing liquid containing an inorganic compound or a hydrophilic layered inorganic compound-containing liquid containing the hydrophilic layered inorganic compound is placed on a base and dried, and the hydrophobic layered inorganic compound layer or the hydrophilic The hydrophobic layered inorganic compound-containing liquid or the hydrophilic layered inorganic compound-containing liquid is formed after the first step of forming a layered inorganic compound layer on the base and peeling the formed layered inorganic compound layer from the base. The soaked layered inorganic compound is dried by placing the hydrophobic layered inorganic compound-containing liquid or the hydrophilic layered inorganic compound-containing liquid on the entire periphery of the soaked layered inorganic compound layer and drying it. Object layer and performing at least once a second step of forming on the entire circumference of the different types of layered inorganic compound layer the soaked layered inorganic compound layer and.

Furthermore, the manufacturing method of the inorganic compound film | membrane of Claim 12 which concerns on this invention is a manufacturing method of the inorganic compound film | membrane of Claim 11, Said hydrophobic layered inorganic compound containing liquid or said hydrophilic property used in said 2nd process. The layered inorganic compound-containing liquid is characterized in that the layered inorganic compound constituting the immersed layered inorganic compound layer does not disperse.
Furthermore, the electronic paper of Claim 13 which concerns on this invention is an inorganic compound film | membrane as described in any one of Claims 1-7, or the inorganic compound film | membrane as described in any one of Claims 8-12. The inorganic compound film obtained by the manufacturing method is characterized in that at least a part thereof is formed.

Furthermore, the flexible substrate of Claim 14 which concerns on this invention is an inorganic compound film as described in any one of Claims 1-7, or the inorganic compound film as described in any one of Claims 8-12. The inorganic compound film obtained by the manufacturing method is characterized in that at least a part thereof is formed.
Furthermore, the flexible printed circuit board of Claim 15 which concerns on this invention is an inorganic compound film as described in any one of Claims 1-7, or the inorganic compound film as described in any one of Claims 8-12. The inorganic compound film obtained by the manufacturing method is characterized in that at least a part thereof is constituted.

Furthermore, the board | substrate of Claim 16 which concerns on this invention is a board | substrate which has an electronic device provided with a non-light-emitting organic semiconductor or an amorphous inorganic semiconductor, and has gas barrier property, Comprising: As described in any one of Claims 1-7. Or an inorganic compound film obtained by the method for producing an inorganic compound film according to any one of claims 8 to 12, wherein at least a part of the inorganic compound film is formed.
Furthermore, the gas barrier film of Claim 17 which concerns on this invention is a gas barrier film which protects the electronic device provided with a nonluminous organic semiconductor or an amorphous inorganic semiconductor from gas, Comprising: As described in any one of Claims 1-7 An inorganic compound film or an inorganic compound film obtained by the method for producing an inorganic compound film according to any one of claims 8 to 12 is at least partially configured.

  The inorganic compound film of the present invention is excellent in water resistance and has high gas barrier properties and transparency. Moreover, the manufacturing method of the inorganic compound film | membrane of this invention can manufacture the inorganic compound film | membrane which is excellent in water resistance and has high gas barrier property and transparency.

  A conventional transparent film containing a layered inorganic compound has high gas barrier properties, flexibility, and self-supporting strength, but when left in the air, the haze increases and the film becomes cloudy and the transparency decreases. was there. In addition, since the film swells and the layered inorganic compound disperses in water and the form of the film collapses due to a small amount of water adhering, there is a problem that the film cannot be used in a process using water. It was. For this reason, for example, when an attempt is made to use the film on the substrate of the display, foreign matter or the like attached to the surface of the substrate cannot be washed away with water. This means that even if the gas barrier property is high, the application that can be applied to a film without water resistance is very limited.

  In order to suppress the increase in haze, maintain transparency, and improve water resistance, studies such as forming a film by applying a layer having a composition different from clay such as a transparent resin were also conducted. The heat resistance of these application layers is low, so the heat resistance of the film is greatly reduced, or the coefficient of linear expansion with respect to temperature change is large, unlike that of the layered inorganic compound layer, so the film is warped or a defect occurs in the film due to stress There may have been problems.

  Accordingly, as a result of intensive studies to solve the above problems, the present inventors have determined that a hydrophilic layered inorganic compound having a hydrophilic layered inorganic compound having a high affinity for water and being easily dispersible in water as a main component. By laminating a hydrophobic layered inorganic compound layer, which has a hydrophobic layered inorganic compound that has a high affinity for an organic solvent and is easily dispersed in an organic solvent as a main component, and a low affinity for water, it has high gas barrier properties. In addition, the present inventors have found that an inorganic compound film having excellent water resistance and having a transparent and sufficient self-supporting strength that hardly causes an increase in haze over time in the atmosphere can be obtained.

  That is, the inorganic compound film of the present invention is a transparent film formed by laminating two or more layered inorganic compound layers having a structure in which a large number of layered inorganic compound particles are oriented and laminated, and has an affinity for an organic solvent. Hydrophobic layered inorganic compound layer composed of only the hydrophobic layered inorganic compound which is high and easily dispersible in organic solvents or composed of the hydrophobic layered inorganic compound and an additive, and has a high affinity for water and is easily dispersible in water A layered inorganic compound alone or a hydrophilic layered inorganic compound layer composed of the hydrophilic layered inorganic compound and an additive is laminated, has mechanical strength that can be used as a self-supporting film, and is 80% or more Has total light transmittance. And it is preferable that it is a 3 layer structure by which the said hydrophobic layered inorganic compound layer was distribute | arranged on the upper and lower surfaces of the said hydrophilic layered inorganic compound layer. Moreover, it is preferable that the whole of the hydrophilic layered inorganic compound layer has a structure wrapped with the hydrophobic layered inorganic compound layer.

  Since the inorganic compound film as described above includes a hydrophobic layered inorganic compound layer, a hydrophilic layered inorganic compound (for example, a smectite group having a hydratable exchangeable inorganic ion such as sodium or calcium between the layers). Compared with an inorganic compound film made of only clay or mica group clay or a film made of the hydrophilic layered inorganic compound and a water-soluble resin, the water resistance is high. Therefore, even if water adheres, the inorganic compound film does not swell immediately and the form does not collapse, and it can be used in a process using water.

  In addition, the inorganic compound film as described above has a total light transmittance of 80% or more, and can be 90% or more by optimizing the composition and process, and has high transparency. As described above, the inorganic compound film of the present invention has a high light transmittance and is transparent, but further has a light transmittance of 80% or more in a wavelength range of 400 nm or more and 800 nm or less, and in some cases 85%. Since it is above, it has transparency which coloring is not recognized with the naked eye over the whole visible light region.

  Further, since the haze value indicating the turbidity of the film is 5% or less, the film has transparency with little light scattering and no turbidity. The haze value is more preferably 3% or less, further preferably 2% or less, and most preferably less than 1%. According to the present invention, such an inorganic compound film is obtained. You can also. Furthermore, it has an excellent property that haze increase with time, which is a problem of conventional films, hardly occurs.

And the inorganic compound which has all the outstanding properties that the total light transmittance is 80% or more, the light transmittance in the wavelength range of 400 nm or more and 800 nm or less is 80% or more, and the haze is 5% or less. It is a membrane. Furthermore, since the nanosheet has a layered inorganic compound layer having a structure in which the nanosheets are extremely densely stacked and the occurrence of defects inside the film is suppressed, high gas barrier properties are maintained.
In addition, the structure in which the particles of the layered inorganic compound are oriented and stacked in the present invention refers to a state in which the layers of the layered inorganic compound are stacked so that the direction of the layer surface is as parallel as possible to the film surface.

Hereinafter, the inorganic compound film of the present invention will be described in more detail.
The kind of the layered inorganic compound used in the present invention is not particularly limited, and clay mineral, layered polysilicic acid, layered silicate, layered double hydroxide, layered phosphate, layered transition metal oxyacid salt (for example, Titanium / niobate, hexaniobate, molybdate), layered manganese oxide, and layered cobalt oxide. However, in order to obtain a transparent film, it is necessary that the layered inorganic compound is not colored or the degree of coloring is slight. Furthermore, when dispersed in a solvent, it is important to cleave and disperse the nanosheet as a unit layer as much as possible. Particularly suitable as the layered inorganic compound is a clay mineral.

  Clay minerals are roughly classified into crystalline minerals and amorphous minerals, and all crystalline parts are phyllosilicates, meaning `` leafy '', and because of their leafy shape, they are basically layered that characterizes layered inorganic compounds. It has a structure. Many clay mineral particles are mainly tetrahedral sheets with a thickness of about 0.2 nm to about 0.5 nm composed mainly of oxygen (O), silicon (Si), aluminum (Al), magnesium (Mg), etc. In addition, the clay mineral particles have a large aspect ratio with a size in the major axis direction of about several tens nm to 5 μm. .

The tetrahedron sheet and the octahedron sheet will be described in more detail. In many cases, the tetrahedral sheet is formed by connecting SiO ₄ tetrahedrons formed by coordinating four Os to Si and connecting the three Os in a hexagonal network. In some cases, Si may form an AlO ₄ tetrahedron instead of Al. In addition, iron (Fe) or the like may form a tetrahedron.

  On the other hand, the octahedral sheet is often formed by coordination of six hydroxyl groups (OH) or O to Al, and may be formed of magnesium (Mg) or Fe instead of Al. is there. Further, due to the fact that Si is replaced with Al or the like in the tetrahedral sheet, or Al is replaced with Mg or the like in the octahedral sheet, the sheet charge is often excessive or insufficient, and the sheet is often charged with a permanent charge. Artificially, elements other than those described above can be introduced into the tetrahedron sheet or octahedron sheet while being controlled, and attempts have been made to change various physical properties such as magnetic characteristics and optical characteristics.

  Various layered inorganic compounds are produced by such a tetrahedral sheet or octahedral sheet, or by laminating and bonding these sheets. In the present invention, a unit layer in which these sheets are bonded is defined as a nanosheet. For example, as a material composed of a nanosheet having only a tetrahedral sheet as a unit layer, a series of minerals (for example, magadiite) generally called layered polysilicic acid can be used. On the other hand, it is known that by having negative ions such as carbonate ions between the octahedral sheet having a positive charge and the octahedral sheet, a kind of clay mineral called hydrotalcite is formed. It has been.

  In many clay minerals, nanosheets are formed by bonding tetrahedral sheets and octahedral sheets. Clay minerals, in which nanosheets, which are unit layers of minerals, are formed by combining tetrahedron sheets and octahedron sheets in a ratio of 1: 1 and laminating, are generally called carionite minerals, and caryonite, halloysite Etc. are famous. On the other hand, a tetrahedron sheet and an octahedron sheet are bonded and laminated at a ratio of 2: 1 (that is, a tetrahedron sheet-octahedron sheet-tetrahedron sheet), and a nanosheet which is a unit layer is formed. Examples of clay minerals include pyrophyllite, talc, smectite group clay, vermiculite, and mica clay mineral.

  In particular, clays belonging to the smectite group (for example, montmorillonite, saponite, hectorite, stevensite, etc.) are generally used in highly polar solvents such as water and alcohol (especially water) in the case of general ones having inorganic cations between layers. On the other hand, it can be dispersed uniformly, and it is said that it can be dispersed in units of one unit layer in a highly polar solvent. In addition, most of the clays belonging to the mica group have a large size in the surface direction of the nanosheet, and although it is difficult to disperse the unit layers one by one, it is possible to expect a high gas barrier property by forming a nanocomposite.

  The kind of clay mineral that can be suitably used in the present invention is not particularly limited, and may be natural clay or synthetic clay. However, since natural clay is generally difficult to obtain high transparency due to the influence of impurities, it is preferable to use synthetic clay that has few impurities and can provide a highly transparent inorganic compound film. As such clay, for example, one or more of mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite, and nontronite are preferable, and synthetic saponite, synthetic hectorite, synthetic steven. Site, synthetic mica, synthetic hydrotalcite, synthetic caryonite and the like are preferable, but clay belonging to the smectite group is more preferable from the viewpoint of dispersibility in a solvent. From the viewpoint of gas barrier properties, natural montmorillonite having a large aspect ratio of the clay crystal layer, clay belonging to the mica group, smectite clay having a high aspect ratio, and the like are preferable.

Most of the layered inorganic compounds, particularly clay minerals in which the nanosheet is charged, are hydrophilic layered inorganic compounds having the property of being dispersed in water or a mixed solvent of water and a highly polar solvent. Therefore, when forming a hydrophilic layered inorganic compound layer, it is preferable to use such a layered inorganic compound, and water or a solvent containing water is generally used as a dispersion medium.
Many of the layered inorganic compounds have inorganic ions such as alkali metal ions, alkaline earth metal ions, and carbonate ions as compensation for the charge of the nanosheet, but as long as the dispersibility in the solvent is not significantly reduced. These inorganic ions may be exchanged for other ions.

  For example, these inorganic ions may be exchanged for lithium ions with an aqueous solution of lithium chloride, lithium nitrate or the like. In this case, lithium ion penetrates into the nanosheet by heating to a high temperature (for example, 300 ° C or higher, preferably 350 ° C or higher) after exchanging with lithium ion, and the negative charge of the nanosheet is reduced, thereby improving water resistance. There is a case that can be made.

Alternatively, by chemically modifying the hydroxyl group present at the end of the nanosheet with, for example, a silane coupling agent or the like, the interaction between the nanosheet and the additive or the interaction between the nanosheets can be increased. May be improved. Further, the water resistance may be improved by modifying a hydroxyl group having a high affinity with water.
As described above, the hydrophilic layered inorganic compound layer refers to a layer formed from any dispersion liquid in which a layered inorganic compound that can be dispersed in water or a solvent containing water is dispersed, and the layer itself It does not matter whether or not is hydrophilic. Therefore, the hydrophilic layered inorganic compound layer in the present invention may be hydrophobized by any method as described above.

On the other hand, hydrophilic layered inorganic compounds are usually not dispersible in organic solvents, and many of them only swell even in polar organic solvents (for example, N-methylformamide, formamide, etc.). It is difficult to cleave and disperse even single-layer nanosheets that are constituents of inorganic compounds.
In order to disperse the layered inorganic compound in the organic solvent, if the layered inorganic compound has a charge, ammonium salt, phosphonium salt, imidazolium salt, pyridinium salt, carboxylic acid, amino acid, sulfonic acid Hydrophobic with improved dispersibility in organic solvents by exchanging exchangeable inorganic ions that the nanosheets have between layers using organic ions such as, and applying an organophilic treatment to give organic functional groups to the nanosheet surface The layered inorganic compound may be used.

  Examples of ammonium salts include ammonium salts having alkyl groups, alkoxy groups, benzyl groups, polyoxyethylene groups, oxyethylene groups, oxypropylene groups, and the like, and quaternary ammonium salts such as dimethyl distearyl ammonium salts and trimethyl stearyl ammonium salts. Can be given. In addition, phosphonium salts and imidazolium salts have higher decomposition and desorption temperatures than quaternary ammonium salts. Therefore, the heat resistance of hydrophobic layered inorganic compounds themselves that have been subjected to organophilic treatment with phosphonium salts or imidazolium salts. It is also suitable for improving the heat resistance of the inorganic compound film comprehensively.

  In addition, in layered inorganic compounds such as kaolinite where the hydroxyl group is exposed on the surface of the nanosheet, the hydroxyl group exposed on the surface of the nanosheet and the organic substance are bonded by chemical treatment such as dehydration, and the surface is modified with the organic substance. It is also possible to obtain a hydrophobic layered inorganic compound. If it is modified to be hydrophobic in this way, the layered inorganic compound can be dispersed in the organic solvent, but a dispersion in which the layered inorganic compound is dispersed in a hydrophobic additive (for example, a polymer) that is dispersed or dissolved in the organic solvent. Therefore, the types of additives that can be selected are dramatically increased. Therefore, not only an inorganic compound film having water resistance can be obtained, but also film properties such as strength and dimensional stability can be controlled widely, and a suitable hydrophobic layered inorganic compound layer can be obtained. In the present invention, one layered inorganic compound layer may be formed using one type of layered inorganic compound or two or more different layered inorganic compounds.

  In particular, a hydrophilic layered inorganic compound layer containing a large amount of the layered inorganic compound has a low coefficient of thermal expansion, and generally has a coefficient of linear expansion of 20 ppm / ° C. or less, preferably 10 ppm / ° C. or less. Therefore, it is important to keep the coefficient of linear expansion of the hydrophobic layered inorganic compound layer low in order to suppress the warpage of the film due to heating and the generation of cracks due to stress applied to the hydrophilic layered inorganic compound layer. For that purpose, it is important that the ratio of the layered inorganic compound in the hydrophobic layered inorganic compound layer is 20% by mass or more, preferably 30% by mass or more, more preferably 40% by mass or more, and further preferably 50% by mass or more. In addition, it is important that the hydrophobic layered inorganic compound layer has a structure in which nanosheets constituting the layered inorganic compound are oriented and laminated.

  Usually, the presence of organic ions in the hydrophobic layered inorganic compound increases the interlayer distance of the nanosheet. For this reason, the density at the time of laminating | stacking a nanosheet falls rather than the case of a hydrophilic layered inorganic compound. For this reason, it becomes easy for gas molecules to pass between layers, and as a result, the demerit that a gas barrier property falls arises. Therefore, it is difficult for the hydrophobic layered inorganic compound layer to have a high gas barrier property, and the high gas barrier property is a layer in which nanosheets are more densely stacked. The entire compound film can have high gas barrier properties.

  Although the kind of additive used in the present invention is not particularly limited, in order to impart a high gas barrier property to the hydrophilic layered inorganic compound layer, the ratio of the additive in the hydrophilic layered inorganic compound layer is 30 mass. It is preferable that it is less than%. That is, it is preferable to contain 70% by mass or more of a layered inorganic compound. The ratio of the additive is more preferably 20% by mass or less, further preferably 15% by mass or less, particularly preferably 10% by mass or less, and most preferably 5% by mass or less. .

  If the solvent of the hydrophilic layered inorganic compound-containing liquid in forming the hydrophilic layered inorganic compound layer is water or a solvent containing water, the additive has hydrophilicity and is dispersible or soluble in water. High is preferred. For example, epsilon caprolactam, dextrin, starch, cellulosic resin, cellulose fiber, gelatin, agar, flour, gluten, alkyd resin, polyurethane resin, epoxy resin, fluororesin, acrylic resin, methacrylic resin, phenolic resin, polyamide resin, polyester resin Polyimide resin, polyvinyl resin, polyethylene glycol, polyacrylamide, polyethylene oxide, protein, deoxyribonucleic acid, ribonucleic acid, polyamino acid, polyhydric phenol, and benzoic acid compounds are preferred.

  Alternatively, an aqueous dispersion material such as latex or emulsion may be used. However, since these are highly dispersible or soluble in water, the water resistance of the inorganic compound film is often low. Therefore, salts, other reactive monomers, polymers, oligomers, and the like may be added, and polymerized by, for example, light or heat to improve the water resistance of the additive itself. By insolubilizing the hydrophilic layered inorganic compound layer with water by such a method, the hydrophilic layered inorganic compound layer and the hydrophobic layered inorganic compound layer do not need to be sandwiched between the hydrophobic layered inorganic compound layers from both sides. You can also

  The thickness of one layer of the hydrophilic layered inorganic compound layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, and more preferably 1 μm or more in order to have sufficient gas barrier properties. Is more preferably 3 μm or more, particularly preferably 6 μm or more, and most preferably 10 μm or more. However, if it is too thick, it may cause a decrease in transparency and increase unevenness on the surface. Therefore, it is preferably 1000 μm or less, more preferably 200 μm or less, and less than 100 μm. Is more preferable.

  On the other hand, since the solvent of the hydrophobic layered inorganic compound-containing liquid when forming the hydrophobic layered inorganic compound layer is an organic solvent, the additive is also hydrophobic and has a high dispersibility or solubility in the organic solvent. preferable. As described above, the gas barrier property of the hydrophobic layered inorganic compound layer tends to be lower than that of the hydrophilic layered inorganic compound layer. However, a certain amount of gas barrier property is imparted to the hydrophobic layered inorganic compound layer, and In order to impart dimensional stability, heat resistance, flexibility, tensile strength, and bending strength to the compound film, the proportion of the additive in the hydrophobic layered inorganic compound layer is preferably 45% by mass or less. More preferably, it is more preferably 30% by weight or less, still more preferably 20% by weight or less, particularly preferably 15% by weight or less, and more preferably 10% by weight or less. Most preferred.

  Examples of such additives include styrene resins, acrylic resins, aromatic polycarbonate resins, aliphatic polycarbonate resins, aromatic polyester resins, aliphatic polyester resins, aliphatic polyolefin resins, and cyclic olefin resins. Thermoplastics such as resin, polyamide resin, polyphenylene ether resin, thermoplastic polyimide resin, polyacetal resin, modified polyvinyl alcohol resin, polyvinyl acetal resin, polysulfone resin, polyethersulfone resin, amorphous fluorine resin Resin and ethylene-vinyl alcohol copolymer (for example, Eval manufactured by Kuraray Co., Ltd.) can be used.

  Also, epoxy resin, thermosetting modified polyphenylene ether resin, thermosetting polyimide resin, urea resin, allyl resin, silicon resin, benzoxazine resin, phenol resin, unsaturated polyester resin, bismaleimide triazine resin, alkyd resin, furan resin Thermosetting resins such as melamine resin, polyurethane resin, and aniline resin can also be used.

  In addition, a photocurable resin can also be used, for example, an epoxy resin containing a latent photocationic polymerization initiator. In addition, when hardening a photocurable resin, you may apply heat simultaneously with light irradiation. Further, a curing agent, a curing catalyst, etc. may be used in combination with the thermosetting resin and the photocurable resin, but these types are generally used for curing the thermosetting resin and the photocurable resin. If there is no particular limitation. Specific examples of the curing agent include polyfunctional amines, polyamides, acid anhydrides, and phenol resins. Specific examples of the curing catalyst include imidazole. These curing agents and curing catalysts can be used alone or in combination. Furthermore, said resin may be used independently and may use 2 or more types together. Since the inorganic compound film needs to be transparent, it is preferable that the additive is also transparent or less colored.

  In addition, as an additive added to the hydrophilic layered inorganic compound layer and the hydrophobic layered inorganic compound layer, not only the above-mentioned polymer type but also various ones can be selected and used as necessary. it can. For example, an inorganic flame retardant such as antimony trioxide is used to impart flame retardancy, a plasticizer such as dimethyl phthalate is used to impart plasticity, and oxidative degradation during heating is suppressed. May add hindered phenol, hindered amine, phosphorus-based or sulfur-based antioxidant, and the like. These additives may be used alone or in combination of two or more.

  The thickness of one layer of the hydrophobic layered inorganic compound layer is preferably 5 μm or more, more preferably 15 μm or more, and more preferably 30 μm or more in order to provide sufficient film strength and water resistance. More preferably, it is more preferably 50 μm or more, particularly preferably 100 μm or more, and most preferably 150 μm or more. However, if it is too thick, it may cause a decrease in transparency and increase unevenness on the surface, so it is preferably 10000 μm or less, more preferably 1000 μm or less, and 300 μm or less. Is more preferable.

  As the solvent for dispersing or dissolving the hydrophilic layered inorganic compound and the hydrophilic additive, water is preferable, but otherwise, organic substances and salts such as acetamide, N, N-dimethylformamide, N-methylpyrrolidone, ethanol and the like. The water which mixed etc. can also be used. The purpose of adding organic matter, salt, etc. is to change the dispersibility of the layered inorganic compound in the dispersion in which the layered inorganic compound is dispersed, to change the viscosity of the dispersion, or to change the ease of drying of the inorganic compound film. Improving the uniformity of the inorganic compound film.

  In addition, as a solvent for dispersing or dissolving the hydrophobic layered inorganic compound and the hydrophobic additive, aromatic hydrocarbons such as toluene and xylene, ethers such as ethyl ether and tetrahydrofuran, ketones such as acetone and methyl ethyl ketone, Aliphatic hydrocarbons such as n-octane, alcohols such as methanol, ethanol and isopropanol, halogenated hydrocarbons such as chloroform, dichloromethane and 1,2-dichloroethane can be used. In addition, N, N-dimethylformamide, N-methylpyrrolidone, dioctyl phthalate, dimethyl sulfoxide, methyl cellosolve, and the like can be used. The type of the organic solvent in which the hydrophobic layered inorganic compound can be dispersed greatly depends on the type of the organic functional group on the surface of the nanosheet that develops the hydrophobic property, and therefore it is necessary to select an appropriate one.

  Such an inorganic compound film of the present invention can be manufactured as follows. That is, the inorganic compound film of the present invention can be produced by alternately forming and laminating hydrophobic layered inorganic compound layers and hydrophilic layered inorganic compound layers. More specifically, a hydrophobic layered inorganic compound-containing liquid containing a hydrophobic layered inorganic compound or a hydrophilic layered inorganic compound-containing liquid containing a hydrophilic layered inorganic compound is placed on a base and dried, and then the hydrophobic layered inorganic compound is dried. After the first step of forming the layer or the hydrophilic layered inorganic compound layer on the base, the hydrophobic layered inorganic compound-containing liquid or the hydrophilic layered inorganic compound-containing liquid is disposed on the lower layered inorganic compound layer and dried. By doing so, it can be produced by performing at least once the second step of forming a layered inorganic compound layer of a type different from the layered inorganic compound layer of the lower layer on the layered inorganic compound layer of the lower layer.

  For example, after a hydrophobic layered inorganic compound-containing liquid in which a hydrophobic layered inorganic compound is dispersed in an organic solvent is placed on the surface of the base and dried to form a hydrophobic layered inorganic compound layer, the hydrophilic layered inorganic compound is dispersed in water. The hydrophilic layered inorganic compound-containing liquid is disposed on the surface of the hydrophobic layered inorganic compound layer and dried to form a hydrophilic layered inorganic compound layer, and the hydrophobic layered inorganic compound-containing liquid is again added to the hydrophilic layered inorganic compound layer. When a hydrophobic layered inorganic compound layer is formed on the surface and dried to peel from the base, a three-layered inorganic compound film can be obtained. The number of the layered inorganic compound layers constituting the inorganic compound film is not particularly limited as long as the hydrophilic layered inorganic compound layer and the hydrophobic layered inorganic compound layer are alternately laminated. That is, the second step may be performed any number of times as long as it is performed once or more.

  Therefore, the minimum thing in the inorganic compound film | membrane of this invention is a thing which laminated | stacked the hydrophilic layered inorganic compound layer and the hydrophobic layered inorganic compound layer one layer each as mentioned above. In this case, there is no problem in water resistance on the hydrophobic layered inorganic compound layer side, and the performance of the inorganic compound film is enhanced by the high strength and dimensional stability generally possessed by the hydrophobic layered inorganic compound layer. However, in such a two-layer structure, if the hydrophilic layered inorganic compound layer does not have water resistance, the water resistance of the entire film will be insufficient.

  Therefore, an inorganic compound film having a three-layer structure in which the hydrophobic layered inorganic compound layers 1 and 1 are arranged on both upper and lower surfaces of the hydrophilic layered inorganic compound layer 2 as shown in FIG. 1 is particularly preferable. Since such an inorganic compound film has a structure in which the upper and lower surfaces of the hydrophilic layered inorganic compound layer 2 are covered with the hydrophobic layered inorganic compound layers 1 and 1, it is excellent in water resistance and hardly invades moisture. As a result, increase in haze over time is unlikely to occur, and the high gas barrier performance of the hydrophilic layered inorganic compound layer 2 is maintained over a long period of time. In addition, since such an effect can be expressed with a minimum number of layers, a decrease in transparency due to an increase in film thickness and multilayering can be minimized, and an inorganic compound film can be formed with a small number of steps. Since it can be manufactured, it is suitable for mass production.

  However, even if the hydrophilic layered inorganic compound layer and the hydrophobic layered inorganic compound layer are laminated one by one (two-layer structure), the water resistance of the hydrophilic layered inorganic compound layer is sufficiently improved by some method. If possible, it is possible to obtain a transparent inorganic compound film having excellent water resistance, flexibility and gas barrier properties, and excellent dimensional stability. That is, after the formation of the hydrophilic layered inorganic compound layer, a method of removing an element that exhibits hydrophilicity by external stimulus such as heat or light (for example, the method of reducing charge by lithium as described above, the external stimulus, etc. The water resistance of the hydrophilic layered inorganic compound layer may be improved by a method using a known technique such as a method of using an additive that is polymerized and hydrophobized by the above.

Therefore, if the water resistance of the hydrophilic layered inorganic compound layer can be sufficiently improved, the hydrophilic layered inorganic compound layer is disposed on both the upper and lower surfaces of the hydrophobic layered inorganic compound layer, contrary to that shown in FIG. Alternatively, an inorganic compound film having a three-layer structure may be used. In this case, since two hydrophilic layered inorganic compound layers having high gas barrier properties are provided, very high gas barrier properties are exhibited.
In the above-described production method, the drying in the first step may not be performed until the layered inorganic compound layer reaches a completely dry state, and when the layered inorganic compound-containing liquid is disposed in the second step, It is sufficient that the mixed liquid and the lower layered inorganic compound layer are not mixed and dried to such an extent that a multilayer structure can be formed substantially. For example, if a layered inorganic compound-containing liquid that has a high thixotropic property and is solidified in a gel state in a short time after being placed on the lower layered inorganic compound layer is used, the layered inorganic compound layer before the lower layer is completely dried. Even so, it can be used in the second step.

  Further, in the above-described manufacturing method, before performing the second step, the layered inorganic compound layer formed on the base in the first step is peeled off from the base, and the upper and lower surfaces or one surface of the separated layered inorganic compound layer is removed. The second step may be performed at least once. When the layered inorganic compound-containing liquid is disposed on the lower layered inorganic compound layer, a method of applying the layered inorganic compound-containing liquid by bar coating or the like may be used.

  Furthermore, the hydrophobic layered inorganic compound-containing liquid or hydrophilic layered inorganic compound-containing liquid used in the second step is preferably a composition that does not disperse the layered inorganic compound constituting the lower layered inorganic compound layer. . Here, the composition of the layered inorganic compound-containing liquid that does not disperse the layered inorganic compound constituting the lower layered inorganic compound layer will be described. When the lower layer is a hydrophobic layered inorganic compound layer, a hydrophilic layered inorganic compound-containing liquid is used in the second step, but the solvent for dispersing or dissolving the hydrophilic layered inorganic compound and hydrophilic additive is used. The composition which is the main component of the liquid in the hydrophilic layered inorganic compound-containing liquid is meant. On the other hand, when the lower layer is a hydrophilic layered inorganic compound layer, the hydrophobic layered inorganic compound-containing liquid is used in the second step, but the hydrophobic layered inorganic compound and the hydrophobic additive are dispersed or dissolved. It means a composition in which the solvent is the main component of the liquid in the hydrophobic layered inorganic compound-containing liquid.

  Furthermore, the inorganic compound film of the present invention can also be produced by the following immersion method. That is, the inorganic compound film of the present invention is dried by disposing a hydrophobic layered inorganic compound-containing liquid containing a hydrophobic layered inorganic compound or a hydrophilic layered inorganic compound-containing liquid containing a hydrophilic layered inorganic compound on a base. After forming the hydrophobic layered inorganic compound layer or the hydrophilic layered inorganic compound layer on the base and performing the first step of peeling the formed layered inorganic compound layer from the base, the hydrophobic layered inorganic compound-containing liquid or hydrophilic The immersed layered material is immersed in the layered inorganic compound-containing solution, and the hydrophobic layered inorganic compound-containing solution or the hydrophilic layered inorganic compound-containing solution is disposed around the entire periphery of the immersed layered inorganic compound layer and dried. It can be produced by performing at least one second step of forming a layered inorganic compound layer of a type different from the inorganic compound layer on the entire periphery of the immersed layered inorganic compound layer. Kill.

  In addition, it is preferable that the hydrophobic layered inorganic compound-containing liquid or the hydrophilic layered inorganic compound-containing liquid used in the second step has a composition in which the layered inorganic compound constituting the immersed layered inorganic compound layer is not dispersed. . Here, the composition of the layered inorganic compound-containing liquid that does not disperse the layered inorganic compound constituting the immersed layered inorganic compound layer will be described. In the case where the immersed layered inorganic compound layer is a hydrophobic layered inorganic compound layer, a hydrophilic layered inorganic compound-containing liquid is used in the second step, but the hydrophilic layered inorganic compound and hydrophilic additive are dispersed. Alternatively, it means a composition in which the solvent to be dissolved is the main component of the liquid in the hydrophilic layered inorganic compound-containing liquid. On the other hand, when the immersed layered inorganic compound layer is a hydrophilic layered inorganic compound layer, the hydrophobic layered inorganic compound-containing liquid is used in the second step, but the hydrophobic layered inorganic compound and the hydrophobic additive are used. Means a composition in which the solvent for dispersing or dissolving is the main component of the liquid in the hydrophobic layered inorganic compound-containing liquid.

  For example, the layered inorganic compound-containing liquid is vigorously shaken by adding the layered inorganic compound to the solvent, and after obtaining a dispersion in which the layered inorganic compound is uniformly dispersed in the solvent, an appropriate additive or additive is added as necessary. It can be prepared by adding a dispersed or dissolved solution and shaking vigorously. At this time, by shaking at a temperature higher than room temperature, the dispersion of the layered inorganic compound can be promoted, and the additive can be mixed more uniformly. Furthermore, if necessary, the layered inorganic compound and the additive may be further dispersed using a known method suitable for dispersing the layered inorganic compound such as a homogenizer or an ultrasonic wave.

  The viscosity of the layered inorganic compound-containing liquid may be low, but it is preferable to use a paste-like layered inorganic compound-containing liquid having high viscosity and low fluidity. The paste-like layered inorganic compound-containing liquid can be prepared by a method of increasing the solid ratio by evaporating and concentrating the solvent, or a method of adding a thickener or the like. Drying can be completed in a short time by using a layered inorganic compound-containing liquid that has a solid content concentration and is in the form of a paste. Further, by using the same layered inorganic compound-containing liquid, advantages such as that the layered inorganic compound-containing liquid applied to the base does not flow out due to low fluidity can be obtained. Since there is no fear that the layered inorganic compound-containing liquid flows out, it is not necessary to use a base having a flow-out prevention structure such as a partitioned container.

  If air bubbles are mixed in the layered inorganic compound-containing liquid disposed on the base by coating or the like, the air bubbles expand during heating and drying, and the surface of the inorganic compound film may bulge up or have low transparency. There is a possibility that problems such as obtaining an inorganic compound film may occur. Therefore, it is preferable to subject the layered inorganic compound-containing liquid before being disposed on the base to a degassing treatment such as vacuum defoaming. The vacuum defoaming is desirably performed in a state where the viscosity of the layered inorganic compound-containing liquid is lowered, and therefore, it is more preferably performed at a temperature higher than normal temperature and while stirring the layered inorganic compound-containing liquid.

  After applying the layered inorganic compound-containing liquid thus obtained to the base surface with a certain thickness, the solvent is slowly removed to form an inorganic compound film. The method for removing the solvent is not particularly limited, and for example, centrifugation, filtration, vacuum drying, freeze vacuum drying, standing in an inert gas atmosphere, and heat evaporation are preferable. Alternatively, a plurality of these methods may be combined.

  Of these methods, for example, when the heating evaporation method is used, it is preferable to use a flat tray as a base and apply a layered inorganic compound-containing liquid thereto. The tray material is not particularly limited as long as it is a smooth material such as brass. However, in order to prevent the inorganic compound film from being attached to the base after drying, the inorganic compound film can be easily peeled off. It is preferable to use materials such as strong aqueous polypropylene and polytetrafluoroethylene. Or it is also preferable to perform water-repellent treatment such as fluororesin coating or titania coating on the portion of the base to which the layered inorganic compound-containing liquid is applied.

The surface of the base is preferably as smooth as possible. When the surface is not smooth, the roughness of the base surface is transferred to the surface of the inorganic compound film, so that the flatness of the surface of the inorganic compound film is lowered, and light is diffusely reflected, thereby increasing haze.
When the layered inorganic compound-containing liquid is applied to the surface of the base, it is 10 minutes or longer under a temperature condition of 30 ° C. or higher and 90 ° C. or lower (preferably 50 ° C. or higher and 70 ° C. or lower) in a forced air oven or on a hot plate. An inorganic compound film can be obtained by drying for a time or less (preferably 20 minutes to 3 hours).

  According to such a production method, it is possible to produce a transparent inorganic compound film that is excellent in water resistance and hardly causes increase in haze with time in the air. Therefore, for example, a transparent film material such as a transparent film material used for a display, which requires high transparency and requires water resistance due to the use of water in the production process, can be provided.

  The obtained inorganic compound film can be used, for example, as a substrate or a gas barrier film of flexible electronic paper such as an electrophoretic drive type or an electronic powder fluid type. In addition to the advantages of being transparent and flexible, the layered inorganic compound, which is an inorganic substance, can be used suitably for solar cell substrates by taking advantage of the high durability against ultraviolet rays. Furthermore, it can be suitably used for a flexible printed circuit board of an electric circuit and a flexible printed circuit board in which a conductive portion on the circuit board is formed by applying or printing a conductive ink by taking advantage of the insulating property. When used for a flexible substrate or a flexible printed circuit board, since it is transparent, it also has an advantage that alignment by a camera is easy when an electronic component is mounted. Suitable applications of such flexible substrates and flexible printed substrates include RFID tag substrates and copper clad laminates.

  In addition, organic semiconductors typified by pentacene and thiophenes are generally easily deteriorated by oxygen and moisture, and amorphous inorganic semiconductors are not easily affected by oxygen and moisture, although not as much as organic semiconductors. For this reason, in devices such as displays using these, it is necessary to sufficiently prevent oxygen and water vapor from entering. Since the inorganic compound film of the present invention has a high gas barrier property, a flexible substrate for an electronic device having an organic semiconductor or an amorphous inorganic semiconductor that is easily deteriorated by oxygen, moisture, or the like, an organic semiconductor or an amorphous inorganic semiconductor with oxygen or It can also be suitably used as a gas barrier film that protects from gas such as water vapor.

  When applying the inorganic compound film of the present invention to the electronic paper, flexible substrate, flexible printed circuit board, organic semiconductor, or electronic device having an amorphous inorganic semiconductor described above, the inorganic compound film is applied as it is. If necessary, a film having another function on the inorganic compound film (for example, a water vapor barrier film made mainly of an inorganic material, a reinforcing material made of a resin material, a protective layer for preventing scratches, etc., and smoothing the surface) Or the like) may be used.

Hereinafter, the present invention will be described more specifically with reference to examples.
[Example 1]
Synthetic saponite (Smecton SA manufactured by Kunimine Kogyo Co., Ltd.) is used as a hydrophilic layered inorganic compound, synthetic hectorite (Lucent Tight SEN manufactured by Corp Chemical Co., Ltd.) is used as a hydrophobic layered inorganic compound, and water is used as a solvent. Sodium acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) was used as an additive to the hydrophilic layered inorganic compound-containing liquid used.
10.2 g of the hydrophilic layered inorganic compound and 594 ml of pure water were placed in a plastic sealed container together with a rotor, and shaken vigorously at 25 ° C. for 2 hours to obtain a hydrophilic layered inorganic compound dispersion. In addition, 1.8 g of sodium polyacrylate and 594 ml of pure water were placed in a plastic sealed container together with a rotor, shaken vigorously at 25 ° C. for 2 hours, and further stirred for 7 minutes with a homogenizer to obtain an additive dispersion. Obtained.

Next, the hydrophilic layered inorganic compound dispersion liquid and the additive dispersion liquid are placed in a plastic sealed container together with a rotor, shaken vigorously at 25 ° C. for 2 hours, and further stirred with a homogenizer for 20 minutes to remove water. A hydrophilic layered inorganic compound-containing liquid was obtained as a solvent. And this hydrophilic layered inorganic compound containing liquid was put into the vacuum degassing apparatus, and deaerated.
In a B4 size brass tray, a PET film (made by Taisei Laminator Co., Ltd.) having a thickness of 50 μm coated with a silicone resin as a release agent is placed, and the surface of the PET film coated with the silicone resin is hydrophilic. A layered inorganic compound-containing liquid was applied. A hydrophilic lamellar inorganic compound-containing liquid film having a uniform thickness was formed by applying a hydrophilic stratified inorganic compound-containing liquid using a stainless steel ground plate and using a spacer as a guide.

The tray was placed in a forced air oven and heated to dry for about 6 hours at a temperature of 60 ° C. After drying, the formed hydrophilic layered inorganic compound layer was peeled from the PET film to obtain a uniform hydrophilic layered inorganic compound film having a thickness of about 26 μm.
In order to confirm the gas barrier properties of this hydrophilic layered inorganic compound film, the oxygen transmission coefficient was measured with a gas transmission amount measuring device “Gasperm-100” manufactured by JASCO Corporation. As a result, it was confirmed that the oxygen permeability coefficient at room temperature was less than 3.2 × 10 ⁻¹¹ cm ² s ⁻¹ cmHg ⁻¹ , and it had high gas barrier properties.

Next, 1 g of the hydrophobic layered inorganic compound and 99 g of N-methylpyrrolidone are placed in a plastic sealed container together with a rotor, left for 2 days, and then shaken vigorously at 25 ° C. for 1 hour to contain the hydrophobic layered inorganic compound-containing liquid. Got.
The hydrophobic layered inorganic compound-containing liquid using N-methylpyrrolidone as a solvent was placed in a metal tray, and the hydrophilic layered inorganic compound layer (transparent film) produced as described above was immersed therein. Then, the tray was placed on a hot plate and heated at 80 ° C. for about 4 hours to volatilize N-methylpyrrolidone to increase the solid content concentration of the hydrophobic layered inorganic compound-containing liquid. Thereafter, the hydrophilic layered inorganic compound layer with the hydrophobic layered inorganic compound-containing liquid disposed on the entire periphery is pulled up from the metal tray, spread on the PET film coated with silicone resin on the surface, It was dried by heating at 80 ° C. for about 4 hours. As a result, a transparent inorganic compound film having a thickness of about 28 μm and a structure in which the entire hydrophilic layered inorganic compound layer was wrapped with the hydrophobic layered inorganic compound layer was obtained.

The obtained inorganic compound film had a tensile strength of 34 MPa and had mechanical strength that could be used as a self-supporting film. Moreover, the transparency was high and the flexibility was excellent.
In order to confirm the flexibility of the inorganic compound film, it was bent into a cylindrical shape with a radius of 6 mm, but no cracks were generated and no defects were generated. Further, when the transparency of the inorganic compound film was measured with a visible ultraviolet spectrophotometer, it had a transmittance of 80% or more in the range from 344 nm to 800 nm, and no coloring was observed. Furthermore, the total light transmittance of the inorganic compound film measured with a turbidimeter “NDH2000” manufactured by Nippon Denshoku Industries Co., Ltd. was 91.3%, and the haze (haze) was 3.4%.
The inorganic compound film was allowed to stand in air kept at a temperature of 24 ° C. and a humidity of 45% for 1 week, and then the total light transmittance and haze (haze) were measured in the same manner as described above. The rate was 91.9% and the haze (cloudiness) was 4.6%.
Further, when water was dropped on the inorganic compound film, the water flowed down in a water repellent state on the surface of the inorganic compound film, and no change was observed in the inorganic compound film.

[Example 2]
Synthetic saponite (Smecton SA manufactured by Kunimine Kogyo Co., Ltd.) is used as the hydrophilic layered inorganic compound, synthetic hectorite (Lucent Tight SAN manufactured by Coop Chemical Co., Ltd.) is used as the hydrophobic layered inorganic compound, and water is used as the solvent. Sodium polyacrylate (manufactured by Wako Pure Chemical Industries, Ltd.) as an additive to the hydrophilic layered inorganic compound-containing liquid used as a polyvinyl butyral resin (Sekisui Chemical Co., Ltd.) as an additive to the hydrophobic layered inorganic compound-containing liquid Each company's ESREC BX-1) was used.
8 g of the hydrophobic layered inorganic compound, 19.2 g of methanol, and 172.8 g of toluene were placed in a 300 ml Erlenmeyer flask together with a rotor and stirred at 25 ° C. for 2 hours to obtain a uniform hydrophobic layered inorganic compound dispersion. Moreover, 2 g of polyvinyl butyral, 2 g of toluene and 46 g of tetrahydrofuran were put together with a rotor in a 100 ml Erlenmeyer flask and stirred at 25 ° C. for 2 hours to obtain a uniform additive-containing liquid.

Next, 170 g of the hydrophobic layered inorganic compound dispersion liquid and 30 g of the additive-containing liquid are put together with a rotor in a 300 ml Erlenmeyer flask and stirred at 25 ° C. for 2 hours to obtain a uniform hydrophobic layered inorganic compound-containing liquid. Obtained. Then, the hydrophobic layered inorganic compound-containing liquid at about 25 ° C. was placed in a vacuum degassing apparatus and sufficiently deaerated while being stirred for about 5 minutes by a rotor.
A PET film coated with a release agent was laid on a flat portion of a metal tray having a depth of 3 mm, and this hydrophobic layered inorganic compound-containing liquid was poured thereon. And the excess hydrophobic layered inorganic compound containing liquid was removed by mounting and moving a glass rod on the metal tray. Thereby, a hydrophobic layered inorganic compound-containing liquid film having a uniform thickness was formed. This metal tray was placed on a hot plate and dried by heating at 60 ° C. for about 4 hours to form a hydrophobic layered inorganic compound layer on the PET film.

Next, the degassed hydrophilic layered inorganic compound-containing liquid obtained in exactly the same manner as in Example 1 was poured onto the hydrophobic layered inorganic compound layer produced as described above, and the hydrophobic layer having a thickness of about 2 mm was obtained. A layered inorganic compound-containing liquid film was formed. Then, this metal tray is placed in a forced air oven, heated under a temperature condition of 60 ° C. for about 7 hours and dried, and when the PET film is peeled off, the hydrophobic layered inorganic compound layer (thickness is about 17 μm). ) And a hydrophilic layered inorganic compound layer (having a thickness of about 50 μm), an inorganic compound film (film thickness of about 67 μm) was obtained.
This inorganic compound film was measured in the same manner as in Example 1. As a result, it had a transmittance of 80% or more in the range from 316 nm to 800 nm, and a transmittance of 85% or more in the range from 376 nm to 800 nm. However, coloring was not recognized. The total light transmittance was 91.9%, and the haze (haze) was 2.0%.

Example 3
In the same manner as in Example 2, an inorganic compound film (thickness is about 50 μm) and a hydrophobic layered inorganic compound layer (thickness is about 17 μm) and a hydrophilic layered inorganic compound layer (thickness is about 50 μm) are laminated. About 67 μm). However, the liquid containing a hydrophobic layered inorganic compound prepared in exactly the same manner as in Example 2 without being peeled from the PET film and placed on the metal tray so that the PET film was in contact with the bottom surface of the metal tray. Was poured onto an inorganic compound film in which two layers were laminated to form a hydrophobic layered inorganic compound-containing liquid film having a thickness of about 3 mm.

  Then, when this metal tray is placed in a forced air oven, dried by heating for about 7 hours at 60 ° C., and the PET film is peeled off, the hydrophilic layered inorganic compound layer becomes a hydrophobic layered inorganic compound. An inorganic compound film (thickness: about 140 μm) in which three layers were laminated having a structure sandwiched between layers was obtained. The same test as in Example 1 revealed that the flexibility of the inorganic compound film was excellent.

Further, this inorganic compound film was measured in the same manner as in Example 1. As a result, it had a transmittance of 80% or more in the range from 367 nm to 800 nm, and a transmittance of 85% or more in the range from 391 nm to 800 nm. The coloring was not recognized. The total light transmittance was 91.4%, and the haze (cloudiness) was 3.6%.
Next, after this inorganic compound film was left in air kept at a temperature of 24 ° C. and a humidity of 45% for 1 week, the total light transmittance and haze (haze) were measured in the same manner as described above. The total light transmittance was 91.3%, and the haze (cloudiness) was 3.4%.
Further, this inorganic compound film was placed horizontally, and water was dropped on the film surface and left for 6 hours. However, no change that could be visually and palpated was observed.

[Comparative Example 1]
In the same manner as in Example 1, a hydrophilic layered inorganic compound layer containing a hydrophilic layered inorganic compound and sodium polyacrylate was formed on a PET film and peeled from the PET film. The obtained transparent inorganic compound film had a single layer structure and a thickness of about 22 μm.
This inorganic compound film was measured in the same manner as in Example 1. As a result, the inorganic compound film had a transmittance of 80% or more in the range from 264 nm to 800 nm, and no coloring was observed. Further, the total light transmittance was 91.7%, and the haze (haze) was 2.3%.
Next, after this inorganic compound film was left in air kept at a temperature of 24 ° C. and a humidity of 45% for 1 week, the total light transmittance and haze (haze) were measured in the same manner as described above. The total light transmittance was 91.3%, and the haze (cloudiness) was 21.4%.
Furthermore, when water was dropped onto the inorganic compound film, the dripped portion immediately swelled and became a gel, and the original film shape was not retained.

  The inorganic compound film of the present invention has a high gas barrier property due to the hydrophilic layered inorganic compound layer, and is excellent in water resistance and is less prone to increase in haze over time, so it is suitable for a film substrate for display and a gas barrier film. Furthermore, it is also suitable for films for packaging medicines and foods.

It is sectional drawing which shows the structure of the inorganic compound film | membrane which has a 3 layer structure. It is a figure which shows the ultraviolet visible absorption spectrum of an inorganic compound film | membrane.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydrophobic layered inorganic compound layer 2 Hydrophilic layered inorganic compound layer

Claims (17)

In an inorganic compound film formed by laminating two or more layered inorganic compound layers having a structure in which a large number of layered inorganic compound particles are oriented and laminated,
Hydrophobic layered inorganic compound layer composed of only the hydrophobic layered inorganic compound or the hydrophobic layered inorganic compound and an additive having high affinity for the organic solvent and easy to disperse in the organic solvent; The hydrophilic layered inorganic compound layer composed of only the hydrophilic layered inorganic compound that is easy to disperse or the hydrophilic layered inorganic compound and an additive is laminated, and has mechanical strength that can be used as a self-supporting film. And an inorganic compound film having a total light transmittance of 80% or more.   The inorganic compound film according to claim 1, wherein the hydrophobic layered inorganic compound and the hydrophilic layered inorganic compound are made of a clay mineral obtained by synthesis.   The inorganic compound film according to claim 1, wherein the inorganic compound film has a gas barrier property.   The inorganic compound film according to any one of claims 1 to 3, wherein the inorganic compound film has a three-layer structure in which the hydrophobic layered inorganic compound layer is disposed on both upper and lower surfaces of the hydrophilic layered inorganic compound layer.   The inorganic compound film according to any one of claims 1 to 3, wherein the entire hydrophilic layered inorganic compound layer has a structure wrapped with the hydrophobic layered inorganic compound layer.   Haze is 5% or less, The inorganic compound film | membrane as described in any one of Claims 1-5 characterized by the above-mentioned.   The inorganic compound film according to any one of claims 1 to 6, wherein light transmittance in a wavelength range of 400 nm or more and 800 nm or less is 80% or more and 95% or less.   A method for producing the inorganic compound film according to any one of claims 1 to 7 by alternately forming and laminating the hydrophobic layered inorganic compound layer and the hydrophilic layered inorganic compound layer. The hydrophobic layered inorganic compound-containing liquid containing the hydrophobic layered inorganic compound or the hydrophilic layered inorganic compound-containing liquid containing the hydrophilic layered inorganic compound is placed on a base and dried, and the hydrophobic layered inorganic compound is dried. After performing the first step of forming the layer or the hydrophilic layered inorganic compound layer on the base, the hydrophobic layered inorganic compound-containing liquid or the hydrophilic layered inorganic compound-containing liquid is placed on the lower layered inorganic compound layer. The second step of forming a layered inorganic compound layer of a type different from the layered inorganic compound layer on the lower layer by arranging and drying is performed at least once. Method of producing an inorganic compound film.   Prior to performing the second step, the layered inorganic compound layer formed on the base in the first step is peeled off from the base, and the upper and lower surfaces or one side of the peeled layered inorganic compound layer is The method for producing an inorganic compound film according to claim 8, wherein the two steps are performed at least once.   The hydrophobic layered inorganic compound-containing liquid or the hydrophilic layered inorganic compound-containing liquid used in the second step has a composition such that the layered inorganic compound constituting the lower layered inorganic compound layer is not dispersed. The manufacturing method of the inorganic compound film | membrane of Claim 8 or Claim 9.   A method for producing an inorganic compound film according to any one of claims 1, 2, 3, and 5, wherein the hydrophobic layered inorganic compound-containing liquid containing the hydrophobic layered inorganic compound or the hydrophilic layered inorganic film A layered inorganic compound formed by forming a hydrophilic layered inorganic compound-containing liquid containing a compound on a base and drying to form the hydrophobic layered inorganic compound layer or the hydrophilic layered inorganic compound layer on the base. After performing the first step of peeling the layer from the base, the layer is immersed in the hydrophobic layered inorganic compound-containing liquid or the hydrophilic layered inorganic compound-containing liquid, and the hydrophobic layer is entirely applied around the immersed layered inorganic compound layer. The layered inorganic compound-containing liquid or the hydrophilic layered inorganic compound-containing liquid is disposed and dried, whereby the layered inorganic compound layer of a different type from the immersed layered inorganic compound layer is immersed Method of producing an inorganic compound film a second step and carrying out at least once to form the entire periphery of the compound layer.   The hydrophobic layered inorganic compound-containing liquid or the hydrophilic layered inorganic compound-containing liquid used in the second step is a composition that does not disperse the layered inorganic compound constituting the immersed layered inorganic compound layer. The method for producing an inorganic compound film according to claim 11.   The inorganic compound film according to any one of claims 1 to 7, or the inorganic compound film obtained by the method for producing an inorganic compound film according to any one of claims 8 to 12, wherein at least a part of the inorganic compound film is obtained. Electronic paper characterized by being composed.   The inorganic compound film according to any one of claims 1 to 7, or the inorganic compound film obtained by the method for producing an inorganic compound film according to any one of claims 8 to 12, wherein at least a part of the inorganic compound film is obtained. A flexible substrate characterized by being configured.   The inorganic compound film according to any one of claims 1 to 7, or the inorganic compound film obtained by the method for producing an inorganic compound film according to any one of claims 8 to 12, wherein at least a part of the inorganic compound film is obtained. A flexible printed circuit board characterized by being configured.   An electronic device comprising a non-light-emitting organic semiconductor or an amorphous inorganic semiconductor is mounted and has a gas barrier property, the inorganic compound film according to any one of claims 1 to 7, or the claims 8 to 12. A substrate characterized by comprising at least a part of an inorganic compound film obtained by the method for producing an inorganic compound film according to any one of the preceding claims.   It is a gas barrier film | membrane which protects the electronic device provided with a non-light-emitting organic semiconductor or an amorphous inorganic semiconductor from gas, Comprising: The inorganic compound film | membrane as described in any one of Claims 1-7, or any one of Claims 8-12 A gas barrier film comprising at least a part of an inorganic compound film obtained by the method for producing an inorganic compound film according to one item.

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