JP2006188418A - Porous clay film and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a porous clay film that has mechanical strength enough to be utilized as a self-supporting film, excellent flexibility, high heat resistance, is an electrical insulator and has low thermal conductivity and is capable of including various chemical substances inside the film and a method of manufacturing the same. <P>SOLUTION: The clay film is obtained by preparing a uniform dispersion aqueous solution containing clay alone, clay and a minor amount of an additive or clay, a minor amount of the additive and a minor amount of a reinforcing material, casting the dispersion solution into a vessel or applying the dispersion solution on the surface of a supporting body and separating a liquid of the dispersion medium by various solid separation methods, for example, by centrifugal separation, filtration, vacuum drying, vacuum freeze-drying or heat evaporation. The resultant clay film is stripped off from the vessel or the supporting body if need to form the clay self-supporting film. The clay film or the clay self-supporting film is stored under a wet atmosphere and drastically heating the clay film or the clay self-supporting film to form the porous clay film. The method of manufacturing the same and the product of the same are provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a porous clay film, a method for producing the same, and its use. More specifically, the present invention has mechanical strength that can be used as a self-supporting film, has high flexibility, high heat resistance, and is porous. The present invention relates to a novel clay film, a method for producing the same, and the like that are non-conductive to electricity, have excellent heat insulation properties, and can contain various chemical substances inside the film. In the technical field of clay thin film production technology and its products, the present invention has mechanical strength that can be used as a free-standing film in the conventional method, high flexibility, high heat resistance, porous, It is difficult to produce a clay film that is non-conductive, has a low thermal conductivity, and can contain various chemical substances inside the film. Based on this, it has a mechanical strength that can be used as a self-supporting film, and also has excellent flexibility, thermal stability, porosity and its manufacturing technology, and its electrical non-conductivity and heat insulation properties make it easy. It is useful for providing new technologies and new materials such as members that can be used as carriers for forming composites with various chemical substances.

  In general, various production processes under high temperature conditions are used in many chemical industry fields. Therefore, various host materials such as an inorganic porous film such as an alumina porous body and an organic polymer film such as a polyolefin porous film are used as membranes. Various chemical substances such as a catalyst, an enzyme, and an adsorbent are encapsulated in this membrane, and catalytic reaction, adsorption, separation reaction, and the like are performed. However, although the inorganic porous membrane has high heat resistance, it is not flexible. On the other hand, the organic polymer membrane has excellent flexibility, but there is a membrane material that is inferior in heat resistance and has both flexibility and heat resistance. There was a problem of not doing.

  It is known that clay is dispersed in water or alcohol, and the dispersion is spread on a glass plate and allowed to stand and dry to form a film having a uniform particle orientation. A fixed orientation sample for line diffraction has been prepared (Non-Patent Document 1). However, when a film is formed on a glass plate, the film is not porous, and it is difficult to peel off the clay film from the glass plate. There was a problem. Moreover, even if the film was peeled off, the obtained film was brittle and the strength was insufficient.

  Recently, a clay thin film using a Langmuir-Blodgett method has been produced (Non-patent Document 2). However, in this method, the clay thin film is formed on the surface of the substrate made of a material such as glass, and does not become a porous body. Furthermore, a clay thin film having strength as a self-supporting film could not be obtained. Furthermore, conventionally, for example, various methods for preparing functional clay thin films have been reported. For example, a method for producing a clay thin film comprising forming an aqueous dispersion of a hydrotalcite-based intercalation compound into a film and drying (Patent Document 1), and a heat treatment for promoting the reaction between the layered clay mineral and phosphoric acid or a phosphate group Method for producing a layered clay mineral thin film in which the bonded structure of the layered clay mineral is oriented and fixed (Patent Document 2), an aqueous composition for film treatment containing a complex compound of a smectite clay mineral and a divalent or higher metal (Patent Document 2) There are many cases including literature 3). However, until now, there has been no development example of a clay film that is porous, has mechanical strength that can be used as a self-supporting film, and has excellent flexibility.

  As described above, there has been no porous clay film having mechanical strength that can be used as a self-supporting film. On the other hand, in the cosmetics and pharmaceutical fields, suitable spherical organic composite clay minerals (Patent Document 4, Patent Document 5), and manufacture of a wet wet athlete's foot treatment drug in which a clay mineral, an acid and an enzyme are mixed (Patent Document 6, Patent) It has been proposed to combine clay and chemical substances such as literature 7). However, the fact is that clay minerals containing these chemical substances have not been used as free-standing films. In addition, when complexing clay minerals and chemical substances, it is necessary that the clay minerals and chemical substances have an affinity. For this reason, in most cases, the chemical substances to be combined are compatible with clay minerals. Yes, it could not be made without complicated processes such as pretreatment of clay minerals to compound chemical substances that have insufficient affinity with clay minerals. Therefore, in this technical field, there is a strong demand to develop and put to practical use a new porous clay film that has mechanical strength that can be used as a free-standing film and that easily forms a complex with various chemical substances. It was.

JP-A-6-95290 JP-A-5-254824 JP 2002-30255 A JP-A 63-64913 Japanese Patent Publication No. 07-17371 Japanese Patent Laid-Open No. 52-15807 Japanese Patent Publication No.61-3767 Haruo Shiramizu “Clay Mineralogy-Basics of Clay Science”, Asakura Shoten, p. 57 (1988) Y. Umezawa, Clay Science, Vol. 42, No. 4, p. 218-222 (2003)

  Under such circumstances, in view of the above prior art, the present inventors have mechanical strength that can be used as a self-supporting film, and have excellent flexibility under high temperature conditions. In the process of intensive research with the goal of developing a new porous clay membrane that can be used, a uniform dispersed aqueous solution containing clay or clay and a small amount of additive or clay and a small amount of additive and reinforcement is prepared. After the dispersion is poured into the container or applied to the surface of the support, the liquid as the dispersion is separated by various solid-liquid separation methods such as centrifugation, filtration, vacuum drying, freeze vacuum drying, or heat evaporation. Then, after obtaining the clay film, it is peeled off from the container or the support as necessary to obtain a clay self-supporting film, and further, the clay film or the clay self-supporting film is stored in a humid environment. Clay free-standing film By heat treatment, found that porous clay film can be obtained, further extensive research, found a composition of preferred materials and manufacturing methods, and have completed the present invention.

  The present invention has mechanical strength that can be used as a self-supporting film, and also has a technology for producing a clay film having excellent flexibility, thermal stability, and porosity, as well as electrical non-conductivity and heat insulation, It is an object of the present invention to provide a new technology / new material such as a member that can be used as a host for easily forming a complex with various chemical substances.

The present invention for solving the above-described problems comprises the following technical means.
(1) The main component is clay, clay and a small amount of additive, or clay and a small amount of additive and a small amount of reinforcing material. It is flexible and has a structure in which clay layered crystals are laminated. A clay film that can be used as a film and has a porous structure.
(2) The clay film according to (1), wherein the main component of the clay film is natural clay or synthetic clay.
(3) The main component of the clay film is one or more selected from the group consisting of mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite, and nontronite, The clay film according to 1).
(4) The clay film according to the above (1), wherein the additive is a thermopolymerizable monomer or a thermosetting polymer.
(5) The clay film according to (1), wherein the reinforcing material is one or more selected from mineral fibers, glass wool, carbon fibers, ceramic fibers, and plant fibers.
(6) The clay film according to (1), which has an arbitrary planar shape such as a circle, a square, or a rectangle and can be used as a self-supporting film.
(7) The clay film according to (3), wherein the thickness is smaller than 1 mm and the area is larger than 1 cm ² .
(8) The clay film according to (1), wherein the weight ratio of the additive to the total solid is 30% or less.
(9) The clay film according to (1), wherein the weight ratio of the reinforcing material to the total solid is 30% or less.
(10) The clay film according to (1), wherein the porosity is 20 to 70%.
(11) The clay film according to (1), wherein the film has a pore size of about 1 to 20 μm.
(12) The clay film according to (1), which is excellent in flexibility and has no change in the porous structure even at a high temperature of 250 ° C. to 600 ° C.
(13) The clay film according to (1), wherein a direct current electric resistance in a direction perpendicular to the film is 1 megaΩ or more.
(14) The clay film according to (1), wherein a weight ratio of the clay to the total solid is 90% or more.
(15) A member having electrical non-conductivity, insulation, and heat insulation, comprising the porous clay film according to any one of (1) to (14).
(16) The member according to (15), wherein the member is an insulating material, a heat insulating material, or a filter material.
(17) A composite comprising a functional component supported or contained in the porous clay film according to any one of (1) to (14).
(18) Disperse the main component clay, clay and a small amount of additive, or clay and a small amount of additive and a small amount of reinforcing material in water or a liquid which is a dispersion medium mainly composed of water, and uniformly disperse the clay. After preparing the liquid and pouring the dispersion into the container or applying it to the surface of the object, the liquid as the dispersion medium is removed to produce a clay film, and optionally, the clay film is peeled off from the surface of the container or the object. A method for producing a porous clay film, comprising obtaining a clay self-supporting film, further storing the clay film or the clay self-supporting film in a humid environment, and performing a heat treatment of the clay film or the clay self-supporting film.
(19) The method for producing a clay film according to the above (18), wherein the wet environment for storing the self-supporting film is in the range of 50% to 90% relative humidity at normal temperature.

Next, the present invention will be described in more detail.
The present invention comprises a main component clay, clay and a small amount of additive, or clay and a small amount of additive and a small amount of reinforcing material, and has a structure in which the lamination of clay particles is highly oriented, as a self-supporting film. It is a clay film characterized by being porous with available mechanical strength and flexibility.

The main constituent of the clay film of the present invention is natural clay or synthetic clay. Examples of main constituents of the clay film include mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite, and nontronite. Examples of the additive include a monomer that undergoes thermal polymerization and a thermosetting polymer. Examples of the reinforcing material include mineral fiber, glass wool, carbon fiber, ceramic fiber, and vegetable fiber. In the present invention, for example, a clay film having an arbitrary planar shape such as a circle, a square, or a rectangle can be used as a self-supporting film, and a thickness is thinner than 1 mm and an area is larger than 1 cm ^2. . The weight ratio of the additive to the total solid is preferably 30% or less, and the weight ratio of the reinforcing material to the total solid is preferably 30% or less. This clay film has the characteristics that it is a self-supporting film, flexible, easy to process, easily functionalized, has a thickness of, for example, 3 to 100 μm, has an orientation of micrometer, and is highly oriented in the nano order. Regarding the basic performance of the clay film, the heat resistance is 600 ° C., and the tensile strength is equivalent to polypropylene. The porosity is 20 to 70 percent.

  The clay film of the present invention itself uses clay as a main raw material (90% by weight or more), and preferably has a basic structure, for example, a natural or synthetic layer having a layer thickness of about 1 nm, a particle diameter of about 1 μm, and an aspect ratio of about 300. The swellable clay is composed of 90% by weight to 10% by weight, and the size of the molecule is made up of 10% by weight of natural or synthetic low-molecular / high-molecular additives having a molecular size of several nanometers. This clay film is produced, for example, by densely laminating layered crystals having a thickness of about 1 nm, oriented in the same direction. The obtained clay film has a film thickness of 3 to 200 μm, preferably 3 to 100 μm, an area that can be increased to 100 × 40 cm or more, and has high heat resistance. The porosity is 20 to 70 percent.

  Next, the manufacturing method of the porous clay film of this invention is demonstrated. The present invention is a method for producing a clay film, in which a solid raw material containing clay as a main component is dispersed in water or a liquid which is a dispersion medium containing water as a main component to prepare a uniform clay dispersion. After the dispersion is poured into the container or applied to the surface of the object, the liquid as the dispersion medium is removed to produce a clay film. Further, the clay film is optionally peeled off from the container or the object surface, and the clay free-standing film Furthermore, the clay film or the clay self-supporting film is stored in a humid environment, and the clay film or the clay self-supporting film is further heat-treated.

  In the present invention, as clay, natural or synthetic material, preferably, natural smectite and synthetic smectite, or a mixture thereof is added to water or a liquid containing water as a main component, and diluted and uniform. A simple dispersion is prepared. As the clay, one or more members selected from the group consisting of mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite, and nontronite can be used. The concentration of the clay dispersion is suitably from 0.5 to 15 weight percent, more preferably from 1 to 10 weight percent. At this time, if the concentration of the clay dispersion is too thin, there is a problem that it takes too long to dry. Further, when the concentration of the clay dispersion is too high, clay does not disperse well, so that there is a problem that the orientation of clay particles is poor and a uniform film cannot be formed.

  Next, if necessary, a weighed solid or liquid additive is added to the clay dispersion to prepare a uniform dispersion. The additive is not particularly limited as long as it is a thermopolymerizable monomer or a thermosetting polymer. For example, one or more of epsilon-caprolactam and polyhydric phenol can be used. The weight ratio of the additive to the total solids is 30 percent or less, preferably 1 to 10 percent. At this time, if the ratio of the additive is too low, the effect of the addition does not appear, and if the ratio of the additive is too high, the distribution of the additive and the clay becomes uneven in the prepared film, and the resulting clay The uniformity of the film is lowered and the effect of addition is also diminished.

  Next, if necessary, the weighed reinforcing material is added to the clay dispersion to prepare a uniform dispersion. As the reinforcing material, one or more of mineral fiber, glass wool, carbon fiber, ceramic fiber, and vegetable fiber resin can be used. The weight ratio of the reinforcing material to the total solid is 30% or less, preferably 1 to 10%. At this time, if the proportion of the reinforcing material is too low, the effect of addition does not appear, and if the proportion of the reinforcing material is too high, the distribution of the reinforcing material and the clay becomes uneven in the prepared film, and the resulting clay The uniformity of the film is lowered and the effect of addition is also diminished. Note that the order of addition of the reinforcing material and the additive is not determined first, and either may be added first.

  Next, after pouring this dispersion into a container or applying it to the surface of an object, the liquid as a dispersion medium is removed by drying to produce a clay film. As a method for producing a clay film, for example, a liquid which is a dispersion liquid is slowly evaporated to form a film. There is a method of applying a dispersion liquid on the surface of a support and drying and removing a liquid as a dispersion medium. As a method for drying and removing the liquid as a dispersion medium, for example, various solid-liquid separation methods such as centrifugation, filtration, vacuum drying, freeze vacuum drying, heat evaporation, or a combination of these methods can be used. It is. Among these methods, for example, when the dispersion is poured into a vessel and the heating evaporation method is used, the clay concentration is adjusted to 0.5 to 3 weight percent, and the dispersion deaerated in advance is preferably a flat tray, preferably Is poured onto a support such as a plastic or metal tray and kept horizontal, in a forced air oven at a temperature of 30 to 70 ° C., preferably at a temperature of 30 to 50 ° C. Dry for about 3 hours to half a day, preferably 3 hours to 5 hours to obtain a clay thin film.

  As another example, when the dispersion is applied to an object and the heating evaporation method is used, the clay concentration is adjusted to 4 to 7 weight percent, and the dispersion deaerated in advance is placed on a flat metal plate. To a thickness of 2 mm, and in a forced air oven at a temperature of 30 to 70 ° C., preferably at a temperature of 30 to 50 ° C., for 10 minutes to 2 hours, preferably 20 minutes to 1 hour. Dry to obtain a clay film.

  If the dispersion is not degassed in advance, there may be a problem that pores derived from bubbles are easily formed in the clay thin film. The drying conditions are set so as to be sufficient to dry and remove the liquid component. At this time, if the drying speed is too slow, there is a problem that it takes time to dry. Further, when the drying rate is too high, there is a problem that convection of the dispersion occurs and the uniformity of the clay film is lowered. The thickness of the clay film can be obtained by adjusting the amount of solid used in the dispersion liquid.

  In the present invention, the concentration of the clay in the clay dispersion is preferably 0.5 to 15 weight percent, more preferably 1 to 7 weight percent, and the drying condition by the heat drying method is preferably forced. Drying for about 10 minutes to half a day, more preferably about 10 minutes to 5 hours, under a temperature condition of 30 ° C. to 70 ° C., more preferably under a temperature condition of 30 ° C. to 50 ° C. It is dry.

  When the clay film is used as a self-supporting film, the clay film is peeled off from the container or the object surface to obtain a clay self-supporting film. In the case where the clay thin film does not naturally peel from a support such as a container, the peeling is preferably promoted by evacuation to obtain a self-supporting film. Further, as another method of peeling, it is preferably dried at a temperature of about 110 to 200 ° C. to facilitate peeling and obtain a self-supporting film. At this time, if the temperature is too low, there is a problem that peeling does not easily occur. When the temperature is too high, there is a problem that the additive tends to deteriorate.

  Next, the clay film or the clay self-supporting film is stored in a forced convection oven maintained at a temperature near room temperature and in a range of 50% to 90% relative humidity. At this time, as long as the above temperature and humidity conditions are obtained stably, it does not necessarily have to be in a forced convection oven. The clay stored under the above conditions contains moderate moisture, and this moisture becomes vapor during the heat treatment described later, resulting in voids in the film. At this time, when the relative humidity is lower than 50%, the water content of the clay is not sufficient, and as a result, the intended porous body cannot be obtained. Further, when the relative humidity is higher than 90%, there is a problem that the moisture content of the clay is excessive and a uniform porous body cannot be obtained. It is desirable to keep the storage time for 1 hour or more.

  Next, the clay film or the clay self-supporting film is rapidly heated to vaporize water contained in the clay, polymerize a thermopolymerizable monomer, or cure the thermosetting resin. As an apparatus used for this treatment, a hydraulic press capable of heating a ram, a microwave oven, and the like are conceivable, but this is not limited as long as the purpose of rapid heating is achieved. When heated slowly in a forced convection oven or the like, the temperature of the sample rises little by little, so that the sample is dried to a thermal polymerization temperature of 200 ° C. or higher, or a thermosetting temperature, and as a result, does not become porous.

The clay self-supporting film of the present invention can be easily cut into an arbitrary size and shape such as a circle, a square, and a rectangle with, for example, scissors and a cutter. The clay free-standing film of the present invention preferably has a thickness of less than 1 mm and an area of more than 1 cm ² . The clay film of the present invention has mechanical strength that can be used as a self-supporting film, has high flexibility, high heat resistance, is porous, is non-conductive to electricity, and has a thermal conductivity. It has a feature that it is low and can contain various chemical substances inside the film.

Therefore, the clay film of the present invention can be widely used as a catalyst support material in a chemical process. For example, it can be used as a reaction filter member that supports palladium fine particles and synthesizes phenol from benzene.
It is possible to enclose various chemical substances in the porous body. The chemical substance is not particularly limited as long as it can be obtained as a liquid or a solution, and examples thereof include inorganic compounds, organic compounds, enzymes, catalysts, adsorbents, hydrophilic and hydrophobic resins.

  As a catalyst carrier, heat resistance is one of the important performances. This is because of the demand for conducting the chemical reaction under high temperature conditions. For example, when the chemical reaction is an endothermic reaction, the chemical equilibrium is advantageous to the production system under a high temperature condition, and the yield is increased. Therefore, the reaction is required to be performed under a high temperature condition. Moreover, since the reaction rate generally increases at high temperatures, a rapid process becomes possible, and it is required to perform the reaction under high temperature conditions. When producing a clay film having high heat resistance, it is important to reduce the amount of an additive inferior in heat resistance compared to clay. In this case, the weight ratio of the additive to the total solid is preferably 10% or less. This is not the case when heat resistance is not particularly required.

  As described above, it is possible to use this clay film or a catalyst film supported on this clay film as a reaction filter member. At this time, the catalytic activity may be at least one of clay, additive, reinforcing material, and catalyst. For example, clay may have catalytic ability, and clay can be selected to develop catalytic ability. At this time, the clay is a main component forming the structure of the clay film and also functions as a catalyst. On the other hand, the additive added when producing the clay film may have catalytic ability, and the additive can be selected in order to develop catalytic ability. At this time, the additive is a component that forms the porous structure of the clay film and also functions as a catalyst. On the other hand, the reinforcing material added when producing the clay film may have catalytic ability, and the reinforcing material can be selected in order to develop catalytic ability. At this time, the reinforcing material reinforces the clay film and also functions as a catalyst. As described above, when the catalytic activity is provided by any one of clay, additives, and reinforcing materials, it may not be necessary to support the catalyst as another component.

  The method for supporting the catalyst on the clay film as a carrier is not particularly limited as long as the catalyst is uniformly encapsulated in the clay film, but for example, an impregnation method is used. This is because the catalyst is uniformly supported on the clay film by, for example, immersing the clay film in a solution in which the catalyst is dissolved or dispersed, impregnating the clay film with the solution, and removing the liquid as necessary. is there.

  The clay film of the present invention can be widely used as an enzyme carrier material in a chemical process. For example, it can be used as a reaction filter member that supports glucose oxidase and oxidizes glucose. Further, it can be used as a film having a bactericidal function by carrying a bactericidal agent such as hinokitiol. Furthermore, since clay and various chemical substances have affinity, it can be used widely as an adsorbing material. For example, it can be used as a chemical substance that causes sick house syndrome, formaldehyde, and an environmental hormone adsorption film. Since the clay film of the present invention is mainly composed of clay, it is excellent in insulation and can be widely used as a heat-resistant insulation film. Moreover, the clay film of this invention is excellent in heat insulation, and can be widely used as a heat insulation film.

  According to the present invention, it is possible to provide (1) a clay film having mechanical strength that can be used as a self-supporting film and having excellent flexibility, thermal stability, and porosity, and a manufacturing technique thereof. It can provide new technologies and new materials such as members that have conductivity and heat insulation and can be used as carriers that easily form composites with various chemical substances. (3) The membrane is made of various chemical substances. (4) The chemical substance is not particularly limited as long as it can be made into a liquid or a solution. For example, enzymes, catalysts, adsorbents, hydrophilic and hydrophobic substances can be used. (5) The present invention has an effect that, for example, a reaction filter member that encloses a catalyst and allows a catalytic reaction to be performed under high temperature conditions can be provided.

  Next, the present invention will be specifically described based on examples, but the present invention is not limited to these examples.

(1) Manufacture of clay film As clay, 0.95 grams of natural montmorillonite (Kunipia P, manufactured by Kunimine Kogyo Co., Ltd.) is added to 60 cm ³ of distilled water, and a Teflon (registered trademark) rotating container in a plastic sealed container. It was put together with the child and shaken vigorously to obtain a uniform dispersion. An aqueous solution containing 0.05 g of epsilon-caprolactam (manufactured by Wako Pure Chemical Industries, Ltd.) as an additive was added to this dispersion, and the resulting dispersion had a flat bottom and a round bottom. Pour into a brass tray with a diameter of about 15 cm, leave the dispersion horizontally, slowly deposit clay particles, and keep the tray level in a forced air oven. It dried for 5 hours under the temperature conditions of 50 degreeC, and obtained the uniform water-soluble polymer composite clay thin film about 30 micrometers thick. The produced clay thin film was peeled from the tray to obtain a clay film. The clay film is cut into 10 cm square, stored in an oven at a temperature of 20 ° C. and a relative humidity of 70% for 12 hours, and then sandwiched between aluminum foils and heated at 250 ° C. for 30 minutes while being pressurized with a hydraulic press at 200 kN. Thus, a white porous clay film was obtained.

(2) Characteristics of clay film The thickness of the porous clay film was about 60 micrometers. Therefore, the porosity was about 50%. An electron micrograph of the porous clay film is shown in FIG. Many pores are observed in the cross section of the membrane. From this photograph, it can be seen that the pore size is about 1 to 20 micrometers. The volume resistivity in the direction perpendicular to the film was 1 × 10 ⁶ Ω or more.

(1) Manufacture of clay film As clay, 0.90 grams of natural montmorillonite (Kunipia P, manufactured by Kunimine Kogyo Co., Ltd.) is added to 30 cm ³ of distilled water, and Teflon (registered trademark) rotating in a plastic sealed container. It was put together with the child and shaken vigorously to obtain a uniform dispersion. To this dispersion, 0.05 g of glass wool was added as a reinforcing material, and an aqueous solution containing 0.05 g of epsilon-caprolactam (manufactured by Wako Pure Chemical Industries, Ltd.) was added as an additive. The solution is applied to a brass plate having a length of about 30 cm and a width of 20 cm, which is left to stand horizontally, dried in a forced air oven at 60 ° C. for 30 minutes, and has a thickness of about 30 μm. A uniform water-soluble polymer composite clay thin film of meters was obtained. Next, the produced clay thin film was peeled from the tray to obtain a clay film. The clay film is cut into 10 cm square, stored in an oven at a temperature of 20 ° C. and a relative humidity of 70% for 12 hours, and then sandwiched between aluminum foils and heated at 250 ° C. for 30 minutes while being pressurized with a hydraulic press at 200 kN. Thus, a white porous clay film was obtained.

(2) Characteristics of clay film The thickness of the porous clay film was about 60 micrometers. Therefore, the porosity was about 50%. From the electron micrograph of the porous clay film, many pores are observed in the cross section of the film. In this way, the self-supporting membrane is stored in a humid environment before heating, resulting in a porous membrane. In the X-ray diffraction chart of this clay film (FIG. 2), a series of sharp bottom surface reflection peaks (001), (003), and (005) are respectively located at 1.48 and 0.50 nm, respectively. Observed, it was shown that the orientation of the clay thin film particles was well aligned. In addition, these values are larger than the values obtained when the film is made of only natural montmorillonite, 1.24, 0.42, and 0.21 nm, respectively, and are nanocomposites in which nylon molecules are inserted between clay layers. It was shown that. From the TG-DTA chart of this clay film (FIG. 3), the weight loss due to heating from 200 ° C. to 600 ° C. was only 8.45%. From this, it was shown that this clay film has high heat resistance.

(1) Manufacture of clay film As clay, 0.90 grams of natural montmorillonite (Kunipia P, manufactured by Kunimine Kogyo Co., Ltd.) is added to 30 cm ³ of distilled water, and Teflon (registered trademark) rotating in a plastic sealed container. It was put together with the child and shaken vigorously to obtain a uniform dispersion. To this dispersion, 0.05 g of glass wool was added as a reinforcing material, and an aqueous solution containing 0.05 g of epsilon-caprolactam (manufactured by Wako Pure Chemical Industries, Ltd.) was added as an additive. The solution is applied to a brass plate having a length of about 30 cm and a width of 20 cm, which is left to stand horizontally, dried in a forced air oven at 60 ° C. for 30 minutes, and has a thickness of about 30 μm. A uniform water-soluble polymer composite clay thin film of meters was obtained. Next, the produced clay thin film was peeled from the tray to obtain a clay film. The clay film is cut into 10 cm square, stored in an oven at a temperature of 20 ° C. and a relative humidity of 70% for 12 hours, and then sandwiched between aluminum foils and heated at 250 ° C. for 30 minutes while being pressurized with a hydraulic press at 200 kN. Thus, a white porous clay film was obtained.

  Next, this porous clay film is impregnated with a saturated aqueous solution of hinokitiol (concentration of about 0.12%), which is a natural antibacterial agent, at room temperature, and water is dried at 60 ° C. so that hinokitiol is included in the porous clay film. Thus, a hinokitiol composite porous clay film was prepared. The surface atomic composition of carbon, oxygen, silicon, and nitrogen of the film before and after the hinokitiol complex was measured by X-ray photoelectron spectroscopy. As a result, before compounding with hinokitiol, they were 75.1% carbon, 19.9% oxygen, 3.5% silicon, and 1.6% nitrogen. In addition, after the hinokitiol complex, carbon was 79.5%, oxygen was 15.4%, silicon was 4.7%, and nitrogen was 0.4%. The carbon source before hinokitiol complex is impurity carbon or carbon of nylon, and after hinokitiol complex, carbon derived from hinokitiol is detected in addition to them. Since the carbon composition increased after hinokitiol complexing, it was shown that hinokitiol was included in the film. Moreover, although the nitrogen source of the film is nylon, the nitrogen composition is low after the hinokitiol complex, indicating that hinokitiol is adsorbed on the nylon surface. This hinokitiol composite clay film is expected to be used as a film material that maintains antibacterial properties over a long period of time due to its sustained release. As described above, the present porous body was shown to be a porous body that can easily enclose a chemical substance by a solution impregnation-drying process.

Comparative Example 1
(1) Manufacture of clay film As clay, 0.95 grams of natural montmorillonite (Kunipia P, manufactured by Kunimine Kogyo Co., Ltd.) is added to 60 cm ³ of distilled water, and a Teflon (registered trademark) rotating container in a plastic sealed container. It was put together with the child and shaken vigorously to obtain a uniform dispersion. To this dispersion, an aqueous solution containing 0.05 g of epsilon-caprolactam (manufactured by Wako Pure Chemical Industries, Ltd.) as a water-soluble polymer was added, and the resulting dispersion had a flat bottom surface and a bottom surface shape. Pour into a brass tray that is round and has a diameter of about 15 cm, leave the dispersion horizontally, slowly deposit clay particles, and keep the tray level, forced air oven The film was dried at 50 ° C. for 5 hours to obtain a uniform water-soluble polymer composite clay thin film having a thickness of about 30 μm. The produced clay thin film was peeled from the tray to obtain a clay film. The clay film is cut into 10 cm square, stored in an oven at a temperature of 100 ° C., dried, then sandwiched between aluminum foils, heated at 250 ° C. for 30 minutes while being pressurized with a hydraulic press at 200 kN, and epsilon caprolactam. A polymerized clay film was obtained.

(2) Characteristics of clay film The thickness of the obtained clay film was about 30 micrometers, and there was almost no change before and after heating. Therefore, the porosity is about 0%. An electron micrograph of this clay film is shown in FIG. No pores are observed in the membrane cross section. As described above, it was shown that a porous film can be obtained by storing the self-supporting film in a humid environment before heating. If the free-standing membrane is not stored in a humid environment before heating, it will not be a porous membrane.

Comparative Example 2
(1) Manufacture of clay film As clay, 0.95 grams of natural montmorillonite (Kunipia P, manufactured by Kunimine Kogyo Co., Ltd.) is added to 60 cm ³ of distilled water. It was put together with the child and shaken vigorously to obtain a uniform dispersion. An aqueous solution containing 0.05 g of epsilon-caprolactam (manufactured by Wako Pure Chemical Industries, Ltd.) as a water-soluble polymer was added to this dispersion, and the resulting dispersion had a flat bottom surface and a bottom surface shape. Pour into a brass tray that is round and has a diameter of about 15 cm, leave the dispersion horizontally, slowly deposit clay particles, and keep the tray level, forced air oven The film was dried at 50 ° C. for 5 hours to obtain a uniform water-soluble polymer composite clay thin film having a thickness of about 30 μm. The produced clay thin film was peeled from the tray to obtain a clay film. The clay film was cut into 10 cm square, stored in an oven at a temperature of 20 ° C. and a relative humidity of 70% for 12 hours, and heated in a forced convection oven at 250 ° C. for 5 hours to obtain a clay film in which epsilon caprolactam was polymerized. .

(2) Characteristics of clay film The thickness of the obtained clay film was about 30 micrometers, and there was almost no change before and after heating. Therefore, the porosity is about 0%. No pores are observed in the membrane cross section. Thus, even if the free-standing film is stored in a humid environment before heating, it does not become a porous film only by slowly heating.

(Manufacture of clay film)
As clay, 0.90 grams of natural montmorillonite (Kunipia P, manufactured by Kunimine Kogyo Co., Ltd.) is added to 30 cm ³ of distilled water, placed in a plastic sealed container with a Teflon (registered trademark) rotor, and shaken vigorously. And a uniform dispersion was obtained. To this dispersion, 0.05 g of glass wool was added as a reinforcing material, and an aqueous solution containing 0.05 g of epsilon-caprolactam (manufactured by Wako Pure Chemical Industries, Ltd.) was added as an additive. The solution is applied to a brass plate having a length of about 30 cm and a width of 20 cm, which is left to stand horizontally, dried in a forced air oven at 60 ° C. for 30 minutes, and has a thickness of about 30 μm. A uniform water-soluble polymer composite clay thin film of meters was obtained. Next, the produced clay thin film was peeled from the tray to obtain a clay film. The clay film is cut into 10 cm square, stored in an oven at a temperature of 20 ° C. and a relative humidity of 70% for 12 hours, and then sandwiched between Teflon (registered trademark) sheets and further sandwiched between ceramic plates to provide 100V, 500 W electrons. A white porous clay film was obtained by heating in a range for 1 minute.

  As described above in detail, the present invention relates to a porous clay film and a method for producing the same, has mechanical strength that can be used as a self-supporting film, and has excellent flexibility, It is possible to provide a new porous clay film that can be used under high temperature conditions, a manufacturing technique thereof, and a product thereof. The present invention makes it possible to provide a film having fine voids between clay particles and excellent in heat resistance. In addition, the clay thin film of the present invention can be used as a free-standing film, has excellent heat resistance and flexibility, and can easily be a complex with various chemical substances. It can be used as a reaction filter. In addition, the present invention can provide a method for producing the clay film in a simple process that does not generate waste liquid. Since the porous clay film of the present invention is excellent in gas barrier properties, insulating properties, and heat resistance, it can be used as an asbestos substitute material in the fields of packing, gaskets, heat insulating materials, flameproofing materials and the like.

It is a cross-sectional photograph by the electron microscope of a clay film. Many holes are observed in the cross section. It is a figure which shows the X-ray diffraction chart of a clay film. It is a figure which shows the TG-DTA chart of a clay film. It is a cross-sectional photograph by the electron microscope of a clay film. No voids are observed in the cross section.

Claims (19)

  The main component is clay, clay and a small amount of additive, or clay and a small amount of additive and a small amount of reinforcing material. A clay film characterized by having a porous structure.   The clay film according to claim 1, wherein the main component of the clay film is natural clay or synthetic clay.   The main component of the clay film is at least one selected from the group consisting of mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite, and nontronite. Clay film.   The clay film according to claim 1, wherein the additive is a thermopolymerizable monomer or a thermosetting polymer.   The clay film according to claim 1, wherein the reinforcing material is one or more selected from mineral fibers, glass wool, carbon fibers, ceramic fibers, and plant fibers.   The clay film according to claim 1, which has an arbitrary planar shape such as a circle, a square, or a rectangle, and can be used as a self-supporting film. The clay film according to claim 3, wherein the thickness is less than 1 mm and the area is greater than 1 cm ² .   The clay film according to claim 1, wherein the weight ratio of the additive to the total solid is 30 percent or less.   The clay film according to claim 1, wherein the weight ratio of the reinforcing material to the total solid is 30% or less.   The clay film according to claim 1, having a porosity of 20 to 70%.   The clay film according to claim 1, wherein the film has a pore size of about 1 to 20 μm.   The clay film according to claim 1, which is excellent in flexibility and has no change in porous structure even at a high temperature of 250 ° C to 600 ° C.   The clay film according to claim 1, wherein a direct current electric resistance in a direction perpendicular to the film is 1 megaΩ or more.   The clay film according to claim 1, wherein a weight ratio of the clay to the total solid is 90 percent or more.   A member having electrical non-conductivity, insulation, and heat insulation, comprising the porous clay film according to claim 1.   The member according to claim 15, wherein the member is an insulating material, a heat insulating material, or a filter material.   A composite comprising the porous clay film according to any one of claims 1 to 14 supporting or containing a functional component.   Disperse the main component clay, clay and a small amount of additive, or clay and a small amount of additive and a small amount of reinforcing material in water or a liquid which is a dispersion medium mainly composed of water, to prepare a uniform clay dispersion. Then, after pouring the dispersion into the container or applying it to the surface of the object, the liquid as the dispersion medium is removed to prepare a clay film, and optionally, the clay film is peeled off from the surface of the container or the object, and the clay is free-standing. A method for producing a porous clay film, comprising obtaining a film, further storing the clay film or the clay self-supporting film in a humid environment, and subjecting the clay film or the clay self-supporting film to heat treatment. The method for producing a clay film according to claim 18, wherein the wet environment for storing the self-supporting film is in the range of 50% to 90% relative humidity at room temperature.