JP5354279B2 - Organic alumina composite thin film and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic material-alumina composite thin film which has such strength that it can be used as a self-supported film, is flexible, avoids the generation of a crack, and has high transparency and functionality. <P>SOLUTION: The organic material-alumina composite thin film comprises an accumulation of an organic material and hydrated alumina particles or alumina particles having a fibrous or acicular shape whose aspect ratio (major axis/minor axis) is 30-5,000, wherein the hydrated alumina particles or alumina particles act apparently as a host. The total amount of the organic material is &le;30 wt.% based on the amount of the alumina composite thin film, and the alumina has orientation and adheres to or is separate from a support. A method for producing the organic material-alumina composite thin film is also provided. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an organic alumina composite thin film and a method for producing the same, and more specifically, retains characteristics unique to inorganic materials such as high heat resistance, high thermal conductivity, and low thermal expansion coefficient, and is highly particle or The present invention relates to an organic alumina composite thin film having pores oriented and having strength that can be used independently, and a method for producing the same. The present invention is an organic alumina composite thin film that has sufficient strength that can be used as a self-supporting film, is flexible, does not generate cracks, has high transparency, and has various functions. New materials useful as optical materials, sensor elements, separation membranes, photoelectrochemical membranes, ion-conducting membranes, etc. that have excellent thermal stability, thermal conductivity, electrical insulation, etc., depending on the organic substance to be selected To do.

  In general, ceramics have excellent physical properties such as strength, heat resistance, thermal conductivity, and low thermal expansion coefficient, and are widely used industrially for substrates, catalyst carriers, electrodes, filters, and the like. In recent years, ceramics are also used as a dispersion medium (host) that uses the porosity and inserts or fixes organic substances in the pores.

  Therefore, control of the shape, size and orientation of the particles and pores forming the ceramic material is extremely important not only for improving the mechanical properties but also for the separation function and the optical function, and various studies have been conducted. ing. For example, a ceramic orientation film is a film in which particles or pores are oriented in a specific direction and has a high anisotropy. It is used for.

  For example, it is known that anisotropy develops in thermal conductivity when particles are highly oriented. Generally, heat is more easily transmitted in the major axis direction as the aspect ratio and orientation of the particles forming the ceramic are higher, and furthermore, as the particle orientation increases, the contact ratio between the particles increases. The conductivity is improved (Non-Patent Document 1). Organic substances typified by resin films generally have low thermal conductivity, and inorganic fillers are added to improve thermal conductivity.

  In the prior literature, studies have been made to improve the physical properties of organic substances by compounding particles having an aspect ratio of 5 to 80 in the organic substances. However, in order to highly orient the particles, it is necessary to add inorganic particles at a high concentration. However, if alumina particles having such a size and shape are added at a high concentration in the resin, the strength and moldability are lowered, and a uniform molded product cannot be obtained. Thus, the actual situation is that no composite film in which an organic substance is inserted into highly oriented high concentration alumina particles has been obtained so far.

  In addition, development and examination of composites in which the pores of porous ceramics are highly controlled and organic compounds are dispersed in the pores are underway. By orienting the organic compound at the molecular level in the controlled pores, it becomes possible to express the original molecular level of the substance and its equivalent functions and performances. Further, by inserting an organic substance into the highly dispersed pores, it becomes possible to highly disperse and fix a compound that has been difficult with a nonporous glass substrate.

  For example, a liquid crystal material or the like uses a rubbing process or a special substrate to align liquid crystal molecules. However, frequent processing can be omitted by inserting into pores whose orientation is highly controlled in advance at the molecular level. Furthermore, since fluorescent materials have low solubility in organic solvents and many compounds with high crystallinity, they are usually coated by the CVD method, but this method has a problem in terms of efficiency. Yes.

  Furthermore, when such a fluorescent material is dissolved in a solvent and formed into a film by dip coating or spin coating on a nonporous glass substrate, a crystal with a high crystallinity becomes enormous during drying, There is a problem that the film becomes non-uniform and the luminous efficiency is lowered. However, by inserting such a light-emitting material into pores controlled at the molecular level after being dissolved in an organic solvent, the crystal can be prevented from becoming enormous and highly dispersed.

  The pores obtained by condensing alumina particles with a small aspect ratio are large, several nanometers to several micrometers, and the shape and direction are irregular, and the pore size and directionality are controlled in the alumina film. In addition, it has been difficult to produce a complex in which an organic substance is inserted. In view of this, various studies have been conducted to produce a porous ceramic material in which the orientation of pores is highly controlled.

  In another prior document, as a method for producing an inorganic porous film having pores oriented in a predetermined direction, liquid crystal molecules are dispersed in a sol containing a metal alkoxide and gelled while applying an electric field. A method for removing liquid crystal molecules from the obtained alignment film is disclosed. However, this type of method requires a special device, requires a voltage to be applied during gelation, has a problem in efficiency, and further depends on the distance between the electrodes. Therefore, it is necessary to control the applied voltage.

  Another prior art document discloses a method of applying a voltage on an aluminum substrate to form a porous alumina film in an acidic aqueous solution, inserting an organic EL light-emitting body therein, and fixing the film. However, this type of method requires a great deal of time for film formation and is integrated with the substrate, so that its use is limited and has problems in terms of flexibility and weight reduction.

  In this way, it retains the unique characteristics of inorganic materials such as high heat resistance, high thermal conductivity, and low coefficient of thermal expansion, highly orients particles or pores at the molecular level, and has strength that can be used independently. In fact, the organic alumina composite thin film has not been obtained, and there has been a strong demand in the art to develop such an organic alumina composite thin film.

JP 2006-062905 A JP 2004-29719 A

J. et al. Appl. Polym. Sci. , 49, 1625 (1993) Japanase Journal of Applied Physics, 43, 7552 (2004)

  Under such circumstances, the present inventors have made extensive studies with the goal of developing the above-mentioned organic alumina composite thin film in view of the above prior art, and as a result, the shape of the alumina sol particles is changed to a fiber or needle. Further, by controlling the aspect ratio, it was found that the alumina particles were oriented and accumulated two-dimensionally, and the present invention was completed.

  The present invention retains the characteristics peculiar to inorganic materials such as high heat resistance, high thermal conductivity, and low thermal expansion coefficient, highly orients particles or pores at the molecular level, and has strength that can be used independently. It is an object of the present invention to provide an organic alumina composite thin film. In addition, the present invention provides an organic alumina composite thin film having sufficient strength that can be used as a free-standing film, flexible, free from cracks, highly transparent, and having various functions. It is intended to provide. Furthermore, the present invention is an organic-alumina composite thin film, which has excellent thermal stability, thermal conductivity, electrical insulation, etc., depending on the organic material selected, optical material, sensor element, separation membrane, photoelectrochemistry An object of the present invention is to provide a new material useful as a membrane, an ion conductive membrane or the like.

The present invention for solving the above-described problems comprises the following technical means.
(1) The aspect ratio (major axis / minor axis) is 30-5000, and consists of alumina hydrate particles or alumina particles having a fibrous or needle-like shape, and an accumulation of organic matter. The alumina particles are apparently an organic alumina composite thin film that is a host, and the total amount of the organic matter is 30% or less by weight with respect to the alumina composite thin film. An organic-alumina composite thin film characterized by having a support and peeling from the support.
(2) The organic alumina composite thin film according to (1), wherein the organic alumina composite thin film exhibits flexibility in a state where the organic alumina composite thin film is peeled off from the support.
(3) The organic alumina composite thin film according to (1) or (2), wherein the alumina hydrate particles are at least one selected from amorphous, boehmite, or pseudoboehmite.
(4) The organic alumina composite thin film according to (1) or (2), wherein the crystal system of the alumina particles is at least one selected from γ, θ, or α.
(5) The organic alumina composite thin film according to (1) or (2), wherein the organic substance has a boiling point of 40 ° C. at the lowest.
(6) The organic alumina composite thin film according to any one of (1) to (5), wherein the thickness of the organic alumina composite thin film is more than 0 to 1000 μm.
(7) The organic alumina composite thin film according to any one of (1) to (6), wherein the alumina hydrate particles or alumina particles have a minor axis of 1 to 10 nm and a major axis of 100 to 10,000 nm.
(8) The organic alumina composite thin film according to any one of (1) to (7), wherein the aspect ratio of the alumina hydrate particles or alumina particles is 100 to 3000.
(9) The organic alumina composite thin film according to any one of (1) to (8), wherein the major axis of the alumina hydrate particles or alumina particles is 700 to 7000 nm.
(10) An aggregate of at least one kind of alumina hydrate particles selected from boehmite or pseudoboehmite is an organic alumina composite thin film that apparently becomes a host of organic matter. The crystal orientation according to any one of (1) to (9), wherein the diffraction intensity ratio d (020) / (120) between the crystallite plane (020) and the crystallite plane (120) is 5 or more. Organic alumina composite thin film.
(11) An aggregate of at least one kind of alumina particles selected from amorphous, boehmite, pseudoboehmite, γ-alumina, or θ-alumina is an organic alumina composite thin film that apparently becomes an organic host, When the bending resistance test based on JIS K5600-5-1 is performed at a film thickness of 100 μm or less in the state immediately after peeling from the support, the cylindrical mandrel has a diameter of 2 mm or more and cracks. The organic alumina composite thin film according to any one of (2) to (10), wherein the organic alumina composite thin film has characteristics that do not show generation.
(12) The organic alumina composite thin film according to (11), wherein the organic alumina composite thin film has a thermal conductivity of 0.1 to 10 W / mK.
(13) The organic alumina composite thin film according to (12), wherein the organic alumina composite thin film has a light transmittance of 0.1 to 100 μm and a total light transmittance of 20% or more.
(14) A method for producing the organic alumina composite thin film according to any one of (1) to (10), wherein the minor axis is 2 to 5 nm, the major axis is 100 to 10,000 nm, and the aspect ratio is 30 to A method for producing an organic alumina composite thin film, comprising applying an aqueous alumina sol in which fibrous or acicular alumina hydrate particles of 5000 are dispersed to a support or an object and drying.
(15) The method for producing an organic alumina composite thin film according to (14), wherein the alumina hydrate particles are at least one selected from boehmite or pseudoboehmite.
(16) The method for producing an organic alumina composite thin film according to (14) or (15), wherein the alumina sol is obtained by hydrolyzing and peptizing aluminum alkoxide.

Next, the present invention will be described in more detail.
The alumina composite membrane of the present invention includes fibrous alumina hydrate particles and / or alumina particles having a specific size and aspect ratio, and an organic substance as essential constituents, and the organic substance is contained in the total mass of the alumina composite film. The total mass is 30% by mass or less, preferably 0.001 to 20% by mass.

  When the total mass of the organic substance with respect to the total mass of the alumina composite film exceeds 30% by mass, the effects expected of alumina hydrate and alumina, that is, low thermal expansion, high thermal conductivity, and orientation effect of alumina particles are obtained. It is not preferable because it is not possible. When the content of the organic compound is less than 0.001% by mass, the effect of adding organic substances in the alumina composite film is reduced, which is not preferable.

  Each component of the alumina composite film will be described. The alumina composite membrane of the present invention is composed of alumina hydrate particles or alumina particles. The alumina hydrate particles and alumina particles constituting the alumina composite membrane of the present invention are fibrous particles having an average aspect ratio of 30 to 5000, an average minor axis of 1 to 10 nm, and an average major axis of 100 to 10,000 nm. . Preferred are fibrous alumina hydrate particles or alumina particles having an aspect ratio of 100 to 3000, an average minor axis of 2 to 5 nm, and an average major axis of 500 to 7000 nm.

  When the average aspect ratio of the particles is less than 30, such as a columnar shape or a plate shape, the flexibility of the alumina composite film is lowered, and furthermore, sufficient strength cannot be obtained, which is not preferable. When the average aspect ratio exceeds 5000, it takes a lot of manufacturing time, and is not practical. When the average minor axis of the particles is less than 1 nm, the particles are likely to aggregate and the strength of the alumina composite film is insufficient. When the average major axis of the particles exceeds 10,000 nm, it takes a lot of time for preparation, which is not preferable.

The crystal system of the alumina hydrate particles constituting the alumina composite film of the present invention is not particularly limited, but is preferably at least one selected from amorphous, boehmite, or pseudoboehmite. Furthermore, it is preferably at least one selected from boehmite and pseudoboehmite. Boehmite is a crystal of alumina hydrate represented by the composition formula Al ₂ O ₃ .nH ₂ O (n = 1 to 1.5). Pseudoboehmite refers to a colloidal aggregate of boehmite.

  As the alumina hydrate is heated, its crystal system transitions to γ, θ, etc., and finally becomes α-alumina. The alumina particles constituting the alumina composite film of the present invention have at least one crystal system selected from γ, θ, α, and more preferably at least one selected from γ, θ.

  The alumina hydrate layer and / or alumina layer in the alumina composite membrane of the present invention is porous, and the alumina hydrate particles and / or alumina particles forming these layers have pores. In the present invention, the term “porous” means that a porous structure is formed by voids formed by fibrous or needle-like particles.

In a pore distribution curve obtained by analyzing by MP method or BJH method as a micropore or mesopore-dependent hysteresis from a nitrogen adsorption isotherm measured at liquid nitrogen temperature, a pore diameter d _peak showing a _peak top Has a pore distribution that is 0.5-20 nm. Here, the MP method is a method for obtaining a micropore volume, a micropore area, a micropore distribution, and the like from an adsorption isotherm (reference: R. S. Mikhal, S. Brunauer, EE Bodor, J.). Colloid Interface Sci., 26, 45 (1968)).

The BJH method is a method for obtaining a mesopore volume, a mesopore surface area, a mesopore distribution, and the like from an adsorption isotherm (Documents: EP Barrett, LG Joyner, PP Halenda, J. Am. Chem. Soc., 73, 373 (1951)). When the pore diameter d _peak indicating the _peak top is less than 0.5 nm, it is difficult to fill the pores with an organic substance, so it is not preferable. Since it falls, it is not preferable.

  The alumina hydrate particles and / or alumina particles forming the alumina layer in the alumina composite film of the present invention have crystal orientation. When utilizing the anisotropy of the film suitable for various physical properties such as thermal conductivity and electrical conductivity of alumina, the alumina hydrate particles in the alumina composite film are heated at a temperature in the range of 100 to 300 ° C. Bake.

  The alumina porous layer obtained by accumulating boehmite or pseudoboehmite particles obtained has an X-ray diffraction intensity ratio d (020) / d (120) of 5 or more between the crystallite face (020) and the crystallite face (120). It is preferable that it has crystal orientation. When d (020) / d (120) is less than 5, desired anisotropy cannot be obtained in the thermal conductivity and electrical conductivity of the alumina composite film.

  In the alumina composite membrane of the present invention, fibrous alumina hydrate particles or alumina particles having the specific size and aspect ratio described above are accumulated to form an alumina hydrate layer and / or an alumina layer. Yes. In the present invention, the accumulation of alumina hydrate particles or alumina particles means that alumina hydrate particles or alumina particles are formed by stacking all or part of the major axis in the plane direction of the film. It means that it is an accumulation.

  Next, an organic compound as an organic substance that becomes a guest in the composite film of the present invention will be described. The following are typical examples, and the present invention is not limited to them. Basically, there is no problem as long as the guest organic matter is not scattered as a gas or a low-viscosity liquid, and any of them can be a guest.

(organic matter)
The organic substance constituting the organic alumina composite thin film of the present invention is an organic compound having a boiling point of 40 ° C. or higher. Examples of organic substances constituting the organic alumina composite thin film of the present invention include synthetic resins, fluorescent substances, proteins (enzymes), nucleic acids, liquid crystal substances, and conductive substances that have a so-called photoluminescence property or electroluminescence property that emits light upon irradiation or energization. Examples include a functional polymer, a fragrance, and a dye.

(Synthetic resin)
The synthetic resin as the organic substance constituting the organic alumina composite thin film of the present invention is a curable resin such as a thermosetting resin or a high energy ray curable resin, or a thermoplastic resin. The thermosetting resin is a resin in which a curable resin precursor is crosslinked and cured by heat, and the high energy beam curable resin is a resin that is crosslinked and cured by a high energy beam such as an ultraviolet ray or an electron beam. Furthermore, the thermoplastic resin refers to a resin that is softened and melted by heating.

  The thermosetting resin as the organic substance constituting the organic alumina composite thin film of the present invention includes epoxy resins, thermosetting polyimides, phenol resins, amino resins such as melamine resins and urea resins, unsaturated polyesters, polyurethanes, and the like. The Moreover, the high energy ray-curable resin constituting the organic alumina composite thin film of the present invention includes an acrylic resin, an epoxy resin obtained by utilizing photocationic polymerization, and the like.

  The thermoplastic resin as the organic material constituting the organic alumina composite thin film of the present invention includes polyethylene, polypropylene, ethylene oxide-propylene oxide copolymer, polyvinyl chloride, polyvinyl acetate, polyethylene glycol, polyethylene oxide, polyvinyl alcohol (partial saponification). Products), polyvinyl acetals (including partially acetalized products), polytetrafluoroethylene, acrylic resins, saturated polyesters such as polyethylene terephthalate, polyamides, polycarbonates, polyamideimides, thermoplastic polyimides, polyethersulfones, and the like.

(Fluorescent substance)
The fluorescent substance as the organic substance constituting the organic alumina composite thin film of the present invention is not particularly limited as long as it is an organic compound that emits fluorescence, such as electroluminescence and photoluminescence. Specifically, tris (8-quinolinolato) aluminum, tris (5-methyl-8-quinolinolato) aluminum, bis (2-methyl-8-quinolinolato) (1-naphtholato) aluminum, bis (8-quinolinolato) magnesium, Bis [benzo (f) -8-quinolinolato] zinc, bis (2-methyl-8-quinolinolato) aluminum oxide, tris (8-quinolinolato) indium, bis (10-hydroxybenzo [h] quinolinolato) zinc, bis (o Metal complex fluorescent materials such as-(2-benzoxazolyl) phenolato) zinc and bis (o- (2-benzotriazolyl) phenolato) zinc are used.

  Also, distyrylbenzene, 1,4-bis (2-methylstyryl) benzene, 1,4-bis (3-methylstyryl) benzene, 1,4-bis (4-methylstyryl) benzene, 1,4-bis Styrylbenzene derivatives such as (3-ethylstyryl) benzene, 1,4-bis (2-methylstyryl) -2-methylbenzene, 1,4-bis (2-methylstyryl) -2-ethylbenzene are used.

  Further, 2,5-bis (4-methylstyryl) pyrazine, 2,5-bis (4-ethylstyryl) pyrazine, 2,5-bis [2- (1-naphthyl) vinyl] pyrazine, 2,5-bis Distyrylpyrazine derivatives such as (4-methoxystyryl) pyrazine and 2,5-bis [2- (4-biphenyl) vinyl] pyrazine; trans-4,4′-diphenylstilbene, 4,4′-bis (benzooxa Stilbene fluorescent dyes such as zolyl) -stilbene and 4,4′-bis (5-phenylbenzoxazolyl) -stilbene are used.

  In addition, a coumarin fluorescent dye such as 3- (2′-benzothiazolyl) -7-diethylaminocoumarin (coumarin 6); 4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran (DCM), 4- (dicyanomethylene) -2-methyl-6- [2- (2,3,6,7-tetrahydro-1H, 5H-benzo [ij] quinolidin-8-yl) vinyl] -4H- A dicyanomethylene fluorescent dye such as pyran (DCM2) is used.

  Furthermore, naphthalimide-based fluorescent dyes such as 4-aminonaphthalic acid phenylimide, 3-ethyl-2- [5- (3-ethyl-2-benzoxazolinylidene) -1,3-pentadienyl] benzoxazolium iodide Polymer (DODCI) and other polymethine fluorescent dyes, 3-nitrophenoxazine, oxazine fluorescent dyes such as 3,7-dinitrophenoxazine, and high molecular fluorescent substances such as polyphenylene vinylene, polyarylene, polyalkylthiophene, and polyalkylfluorene Etc. are exemplified.

(Proteins, biopolymers, etc.)
The biopolymer as an organic substance constituting the organic alumina composite thin film of the present invention is a protein such as an enzyme or a nucleic acid used in food processing and pharmaceutical fields, and is not particularly limited. Specifically, α-amylase, β-amylase, glucoamylase, cellulase, lipase, catalase, glucooxylase, anthocyanase, β-galactosidase, aspartase, glucose isomerase, pectinase, protease, peroxidase, subtilisin, aminoacylase, Examples include penicillinase, lactonase, nitrile hydratase, fumarase, isomerase, various DNAs, various RNAs, and the like.

(Liquid crystal substance)
As the liquid crystal substance as the organic substance constituting the organic alumina composite thin film of the present invention, typically, 2- (4′-cyanophenyl) -6-octylnaphthalene, 2- (4′-pentylphenyl) -6-methoxy Examples include naphthalene, 2-phenylbenzothiazole, 4-cyanophenyl-4-nonylbenzoate, heptylcyanobiphenyl, octylphenylbiphenyl, nonylcyanobiphenyl, 4-cyanophenyl-4-ethylbenzoate, pentylcyanobiphenyl, and the like.

(Conductive polymer)
The conductive polymer as the organic substance constituting the organic alumina composite thin film of the present invention includes polyacetylene, polyaniline, polyparaphenylene, polythiophene, polyparaphenylene, poly3,4-ethylenedioxythiophene, polystyrene sulfonic acid, polyiso Although thionaphthene etc. are illustrated, it is not limited to these.

(Other ingredients)
The organic alumina composite thin film of the present invention may contain an antioxidant, an ultraviolet absorber, a dye, a pigment and the like as a filler as long as the characteristics of thermal expansion and thermal conductivity are not impaired.

  Next, a method for producing an organic alumina composite thin film will be described. Various methods can be applied to the method for producing the organic alumina composite thin film of the present invention, and there are no particular restrictions, but typical examples include the following methods.

(A) A method using an alumina porous self-supporting membrane. This is by immersing alumina porous hydrate particles having the above-mentioned size and shape and / or alumina porous self-supporting membrane in which alumina particles are accumulated in a solution in which various organic substances are dissolved or dispersed in a solvent. After removing the excess organic matter, it is dried and, if necessary, a method of performing a curing treatment such as heating or irradiation with high energy rays, or the above-mentioned organic matter-containing composition is applied to an alumina porous self-supporting film. , Drying and curing methods.

  When using organic resin as a synthetic resin precursor, that is, a synthetic intermediate such as a monomer component, an oligomer having a crosslinkable or polymerizable functional group, or a prepolymer, a polymerization initiator, a curing agent, a curing accelerator, or the like is used as a solvent. Dissolve or disperse.

(B) A method of dissolving or dispersing the above organic substance in an aqueous solvent. This is because the alumina hydrate particles having the above-mentioned size and shape, the above-mentioned organic matter, and the aluminum organic matter mixed dispersion in which a polymerization initiator, a crosslinking agent, a crosslinking accelerator, etc. are dissolved and dispersed as required. In this method, the liquid is applied to a water-repellent support, dried, then peeled off from the support, and further subjected to a curing treatment such as heating or irradiation with high energy rays as necessary.

  When the organic substance is a film-forming synthetic resin, the above-mentioned aqueous dispersion of alumina resin is applied to the synthetic resin film / sheet, dried, and then heated as necessary, or a synthetic resin film / sheet And a method of adhering the porous alumina self-supporting film and the like.

  In the method (b), the aspect ratio of the fibrous alumina hydrate particles may be smaller than the lower limit of the above range depending on the mixing method with the resin solution, the method (a) Then, it is not limited to the solubility in a solvent, The method of (a) is preferable from the viewpoint that a wide range of synthetic resins can be used. However, the film forming method should not be limited to the above methods (a) and (b), and should be selected and devised according to the purpose, depending on the subsequent utilization method. In the case of producing an alumina thermosetting resin composite film, the method (a) is particularly preferable.

  The method (a) will be specifically described by taking an alumina-epoxy resin composite film that is a composite film with an epoxy resin that is a curable resin as an example. An alumina-epoxy resin composite film can be obtained by immersing the alumina porous self-supporting film in an epoxy resin-containing composition, washing excess resin precursors, etc., then removing the dispersion medium and curing it. .

(Alumina porous self-supporting membrane)
The alumina porous self-supporting membrane used in the method (a) can be produced by the method described in the literature (Japanese Patent Application No. 2008-278951 or Japanese Patent Application No. 2008-312762). That is, for example, an aqueous alumina sol in which fibrous alumina hydrate particles having a minor axis of 1 to 10 nm, a major axis of 100 to 10,000 nm, and an aspect ratio of 30 to 5000 are dispersed is applied to a water-repellent support. After drying, the alumina porous self-supporting membrane can be produced by peeling from the support and further heating and firing as necessary.

  The aqueous alumina sol can be produced by hydrolyzing a hydrolyzable aluminum compound and peptizing under acidic or alkaline conditions. By appropriately selecting the type of hydrolyzable aluminum compound and the conditions for hydrolysis and peptization, it is possible to produce an aqueous alumina sol composed of amorphous and boehmite, or alumina hydrate particles that are pseudo boehmite crystal systems. it can. The crystal system of the alumina hydrate particles is preferably boehmite or pseudoboehmite.

  The hydrolyzable aluminum compound includes various inorganic aluminum compounds and aluminum compounds having an organic functional group. Examples of the inorganic aluminum compound include salts of inorganic acids such as aluminum chloride, aluminum sulfate, and aluminum nitrate, aluminates such as sodium aluminate, and aluminum hydroxide.

  Examples of the aluminum compound having an organic functional group include carboxylates such as aluminum acetate, aluminum ethoxide, aluminum isopropoxide, aluminum n-butoxide, aluminum sec-butoxide, and other aluminum alkoxides, cyclic aluminum oligomers, and diisopropoxy. Illustrative examples include aluminum chelates such as (ethylacetoacetate) aluminum and tris (ethylacetoacetate) aluminum, and organoaluminum compounds such as alkylaluminum.

  Among these compounds, aluminum alkoxides are preferable because they have moderate hydrolyzability and easy removal of by-products, and those having a lower alkoxyl group having 2 to 5 carbon atoms are particularly preferable.

  The amount of water is preferably adjusted so that the concentration of fibrous boehmite or pseudoboehmite particles in the aqueous boehmite sol is 0.1 to 20% by mass, and more preferably the concentration of these particles is 0. It adjusts so that it may become 5-10 mass%. When the concentration of fibrous boehmite or pseudo boehmite particles in the aqueous boehmite sol is 0.1% by mass or less, it takes a long time to dry, and when the concentration is 20% by mass or more, the viscosity of the dispersion is high. This is not preferable because it is difficult to obtain a uniform film.

  Alcohol, ketone, ether, water-soluble polymer, and the like can be added to the aqueous alumina sol within a range that does not adversely affect the properties of the target alumina porous self-supporting membrane. After adding a predetermined amount of water and the hydrolyzable aluminum compound, the mixture is heated at 80 to 170 ° C. for 0.5 to 10 hours, and preferably hydrothermally treated at 100 to 150 ° C. for 1 to 5 hours.

  When the heating temperature is less than 80 ° C., it takes a long time for hydrolysis, and even if it is carried out at a temperature exceeding 170 ° C., the increase in hydrolysis rate is slight, requiring a high pressure vessel, etc. Since it is economically disadvantageous, it is not preferable. If the heating time is less than 0.5 hours, it is difficult to adjust the temperature, and even if the heating time exceeds 10 hours, the process time is only increased, which is not preferable.

  Next, the alumina slurry obtained by hydrolysis is peptized by heating in the presence of a specific amount of acid. As the coexisting acid, monovalent acids such as hydrochloric acid, nitric acid, formic acid, and acetic acid are preferable, and acetic acid is particularly preferable.

  The coexistence amount of acetic acid is 0.1 to 2 mol times, preferably 0.3 to 1.5 mol times with respect to the hydrolyzable aluminum compound. When the coexistence amount of acetic acid is less than 0.1 mole times, peptization does not proceed sufficiently, and the desired short diameter is 1 to 10 nm, the long diameter is 100 to 10,000 nm, and the aspect ratio is 30 to 5000. Alternatively, an aqueous alumina sol in which alumina hydrate particles having a needle shape are dispersed cannot be obtained. When the coexistence amount of acetic acid exceeds 2 mole times, stability with time may be lowered, which is not preferable.

  Since the pH of the fibrous and acicular alumina sol of the present invention exhibits an acidity of 2.5 to 4, when used for coatings, films, etc., the substrate may be affected by corrosion. In that case, by adding a pH adjusting reagent and adjusting the pH of the alumina sol to be neutral or alkaline, the influence on the substrate can be suppressed and a coating film can be produced.

  In this case, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogen carbonate or ammonia and organic amines such as ethylamine, tetramethylammonium hydroxide and urea are preferably used as the pH adjusting reagent.

  However, inorganic hydroxides, carbonates and the like are not preferable because the elements remain after firing, and are preferably ammonia and organic amines. Further, when a basic substance such as ammonia or organic amine is generated in the process of forming the alumina porous membrane, the addition of this kind of adjusting reagent is not particularly required.

  Further, when the obtained aqueous alumina sol has a high viscosity, it contains bubbles in the liquid, and therefore, deaeration treatment is required before applying to the support. Bubbles can be removed by using a decompression process, a centrifugal process, or the like. Various resins can be used as the support on which the aqueous alumina sol is applied.

  For example, polyethylene terephthalate, polyester such as polyester diacetate, polycarbonate, fluorine resin such as polytetrafluoroethylene, polypropylene, or the like is used. In the case of a support having water repellency, it is preferable to use a support having water repellency such as polytetrafluoroethylene because it can be easily peeled off at room temperature to obtain a self-supporting film. In the case of Appendix, this is not a limitation, and the support is not particularly limited.

  Various general coating methods can be employed depending on the viscosity of the aqueous alumina sol and the desired shape and size of the film. Examples of the coating method preferably used include a fluency method, a doctor blade coating method, a knife coating method, and a bar coating method.

  As a drying method for removing the dispersion medium, an evaporation method is preferable. The above-mentioned alumina porous self-supporting membrane can be obtained by drying in a temperature-controlled room at 10 to 100 ° C. for about 10 minutes to 5 hours. The thickness of the porous alumina self-supporting membrane can be easily adjusted by the amount of alumina particles in the dispersion medium. An alumina porous self-supporting film having a film thickness of 0.1 to 100 μm can be produced, and a film having a large area of 100 cm × 100 cm can also be produced. It is also possible to change the shape of the film by cutting as appropriate.

(Epoxy resin-containing composition)
An epoxy resin precursor, a curing agent, and, if necessary, a curing accelerator is added to a predetermined solvent to prepare an epoxy resin-containing composition. When a curing agent having a low curing rate, that is, an acid anhydride, an aromatic polyamine, or the like is used, a curing accelerator can be used in combination.

  Epoxy resin precursors include glycidyl ether type epoxy compounds (bisphenol A type, bisphenol F type, phenol novolac type, etc.), alicyclic epoxy compounds (alicyclic diepoxy acetal, alicyclic diepoxy adipate, etc.), glycidyl An ester type epoxy compound (phthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, etc.) is used.

  Furthermore, glycidylamine type epoxy compounds, ie, tetraglycidyl diaminodiphenylmethane, triglycidyl p-aminophenol, etc., heterocyclic epoxy compounds, ie, hydantoin type epoxy compounds such as diglycidyl hydantoin, and known organic epoxy compounds such as triglycidyl isocyanurate And a (co) polymer thereof, or a mixture of a plurality of epoxy resin precursors.

  Curing agents include polyamines such as triethylenetetramine, tetramethylenehexamine, diethylaminopropylamine, N-aminoethylpiperazine, isophoronediamine, m-xylenediamine, and metaphenylenediamine; phenol resins such as phenol novolac resin and aniline modified resole resin ; Acid anhydrides such as methyltetrahydrophthalic anhydride, hexaphthalic anhydride, succinic anhydride; and known compounds such as dicyandiamide can be used. Moreover, ultraviolet curing agents such as dialkyl-4-hydroxyphenylsulfonium salts can also be used.

  As the curing accelerator, known compounds such as tertiary amines such as N, N-dimethylpiperazine and benzyldimethylamine; imidazoles such as 2-methylimidazole; and organic phosphorus compounds such as triphenylphosphine and tetraphenylphosphonium bromide are used. it can.

  Solvents include aromatic hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone and methyl isobutyl ketone; aprotic polar solvents such as dimethyl sulfoxide and N-methyl-2-pyrrolidone; esters such as butyl acetate; ethylene Known solvents such as glycols such as glycol monomethyl ether and propylene glycol monomethyl ether can be used.

  The concentration of the resin in the dispersion medium is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass. If it is 0.01% by mass or less, voids are generated in the alumina porous membrane, which is not preferable, and if it exceeds 20% by mass, it is preferably removed because the loss is increased by a solvent that is thickly coated on the surface of the alumina porous membrane. Absent.

(Dipping, coating, drying, curing)
When the above-mentioned alumina porous self-supporting membrane is immersed in the epoxy resin-containing composition, the immersion time is 5 to 120 minutes, more preferably 10 to 60 minutes. In the case of 5 minutes or less, the epoxy resin precursor, the curing agent, the solvent, etc. cannot sufficiently penetrate into the alumina porous pores, and even if immersed for more than 120 minutes, there is no particular effect, which is not preferable. .

  The alumina porous self-supporting membrane impregnated with the epoxy resin precursor, the curing agent and the like is pulled up from the epoxy resin-containing composition and washed several times with the solvent of the epoxy resin-containing composition. The solvent is dried and removed by a general method such as an evaporation method, and then a curing process (heating, UV irradiation, etc.) is performed by a known method. The curing conditions are appropriately selected according to the resin precursor, curing agent, and curing accelerator.

  An alumina-epoxy resin composite film can also be obtained by applying an epoxy resin-containing composition to the alumina porous self-supporting film. General coating methods such as a fluent method, a doctor blade coating method, a knife coating method, and a bar coating method can be employed.

  Also when using other thermosetting resins, such as a polyimide, an alumina resin composite film can be obtained similarly to an alumina-epoxy resin composite film using the well-known manufacturing method regarding each resin. Even when a thermoplastic resin such as polyvinyl alcohol is used, an alumina thermoplastic resin composite film can be obtained in the same manner as the curable resin by omitting the curing treatment step.

  Here, the method (b) will be described. The alumina organic compound mixed dispersion is applied to a water-repellent support, dried, peeled off from the support, and further heated, high-energy rays as necessary. Curing treatment such as irradiation is performed.

  The aqueous dispersion of alumina resin comprises a powder composed of fibrous alumina hydrate particles having a minor axis of 1 to 10 nm, a major axis of 100 to 10000 nm, and an aspect ratio of 30 to 5000, and a synthetic resin or synthetic resin precursor. , A method of dispersing in an aqueous solvent, a method of dispersing a powder comprising alumina hydrate particles in an aqueous resin solution or dispersion in which a synthetic resin or synthetic resin precursor is dissolved or dispersed in an aqueous solvent, hydration of alumina It can be produced by mixing an aqueous alumina sol in which product particles are dispersed in an aqueous solvent and an aqueous resin solution in which a synthetic resin or a synthetic resin precursor is dissolved or dispersed in an aqueous solvent.

  An aqueous alumina sol in which fibrous alumina hydrate particles having a minor axis of 1 to 10 nm, a major axis of 100 to 10,000 nm, and an aspect ratio of 30 to 5000 are dispersed can be obtained by the method (a).

  The aqueous solvent is a solvent containing water as a main component, and may be water alone, or a mixture of an organic solvent that is water-soluble, preferably water-soluble, preferably at 20 ° C., and water having a desired concentration. There may be.

  As water, any of pure water, ultrapure water, distilled water, ion exchange water and the like can be used, but ion exchange water is preferable. Examples of the water-soluble organic solvent include lower aliphatic alcohols such as methanol, ethanol, propanol and ethylene glycol; lower aliphatic carboxylic acids such as formic acid and acetic acid; N, N-dimethylformamide, N-methyl-2-pyrrolidone and the like. Of aprotic polar solvents.

  In the case of producing an alumina thermoplastic resin composite film, among the above-described thermoplastic resins, those that are dissolved or dispersed in an aqueous solvent (in the present specification, described as a water-soluble thermoplastic resin) can be suitably used. . Examples of the water-soluble thermoplastic resin include polyethylene glycol, polyethylene glycol-polypropylene glycol block copolymer, ethylene oxide-propylene oxide random copolymer, polyvinyl alcohol, water-soluble saturated polyester, water-soluble polyamide, water-soluble polycarbonate and the like.

  In the case of producing an alumina curable resin composite film, the above-described curable resin precursor, and further, if necessary, a curing agent and a curing accelerator are used, but each component is dissolved or dispersed in an aqueous solvent, And must be stable.

  Examples of water-soluble thermosetting resins include resol type phenol resins (which may be modified with urea, melamine, etc.), 2,4,6-tris (methylamino) -1,3,5-triazine, 2-dimethyl. Methylated melamines such as amino-4,6-bis (methylamino) -1,3,5-triazine, methylol melamines such as 2,4,6-trimethylol melamine, trimethylol melamine trimethyl ether, trimethylol melamine Melamine resin precursors such as methylated methylol melamines such as dimethyl ether are used.

  Also, dimethylol urea, dimethylol ethylene urea, 1,3-dimethyl-4,5-dihydroxy-2-imidazolidinone, 1,3-dihydroxymethyl-4,5-dihydroxy-2-imidazolidinone, 1,3 Water-soluble amino resin precursors such as -dihydroxymethyl-2-imidazolidinone, 4,5-dihydroxy-1,3-dimethyl-2-imidazolidinone are used.

  In addition, water-soluble blocked isocyanate resins such as aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; polyalkylene glycol adducts such as isophorone diisocyanate, tolylene diisocyanate, and methylene bis- (4-phenyl isocyanate) Acid, polyester, polyamide, acrylic resin or the like is used.

  By applying the alumina resin aqueous dispersion to the support by the method (a) described above, drying, and performing a curing treatment as necessary, an alumina composite film can be obtained with or without the support. Can do. That is, the alumina composite film can be applied to a support, formed into a film, and then peeled off to be used as a self-supporting film, as well as being used as a coating film without being peeled off from the support. be able to.

The present invention has the following effects.
(1) According to the present invention, it is possible to provide an organic alumina composite thin film having a strength in which particles or pores are highly oriented at the molecular level and can be used independently, and a method for producing the same.
(2) According to the present invention, an alumina organic composite thin film having various functions such as light emission, polarization, refraction, and conductivity can be obtained on various supports.
(3) According to the present invention, an organic-alumina composite thin film having sufficient strength that can be used as a self-supporting film, having flexibility, being free from cracks, having high transparency, and having various functions. Can be obtained.
(4) The organic alumina composite thin film according to the present invention is an organic alumina composite thin film based on alumina, and has an excellent thermal stability, thermal conductivity, electrical insulation and the like according to the organic material to be selected. New materials useful as sensor elements, separation membranes, photoelectrochemical membranes, ion conductive membranes, and the like can be provided.

The present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.
In the following examples, the particles constituting the self-supporting film were identified by X-ray diffraction measurement. X-ray diffraction measurement was performed at a diffraction angle of 2θ: 10 to 90 °. The average major axis, the average minor axis, and the aspect ratio of the fibrous pseudoboehmite particles were determined from average values measured from electron micrographs.

  The intensity ratio of specific crystal planes such as fibrous boehmite particles was shown as the intensity ratio of diffraction peaks of (020) crystal plane and (120) crystal plane of boehmite particles using an X-ray diffractometer. The total light transmittance of the free-standing film was measured with a turbidimeter. The flexibility of the self-supporting film was evaluated by a cylindrical mandrel bending tester according to JIS K5600-5-1 after the film was dried.

As the measuring device, the following devices were used.
X-ray diffractometer (Mac. Sci. MXP-18, tube: Cu, tube voltage: 40 kV, tube current: 250 mA, goniometer: wide-angle goniometer, sampling width: 0.020 °, scanning speed: 10 ° / min, divergence slit: 0.5 °, scattering slit: 0.5 °, light receiving slit: 0.30 mm)
・ Transmission electron microscope (FEI-TECNAI-G20)
Turbidimeter (Nippon Denshoku Industries Co., Ltd., NDH5000)
・ Cylindrical mandrel bending tester BD-2000 (Cortech Corp.)

The linear thermal expansion coefficient was measured as follows. Apparatus: TMA8310 (manufactured by Rigaku), temperature range: 25-100 ° C., heating rate: 5 ° C./min, measurement mode: tension (load 49 mN), atmosphere: N ₂ (50 ml / min)
The thermal conductivity was measured as follows. Apparatus: Auto ΛHC-072 (manufactured by Eihiro Seiki), measuring method: laser flash method, measuring temperature: 40 ° C.

(Reference example)
<Fibrous alumina sol>
In a 500 ml four-necked flask, 300 g of ion-exchanged water was taken, and the liquid temperature was raised to 75 ° C. while stirring. To this, 64 g (0.34 mol) of aluminum isopropoxide was dropped, and while distilling out the generated isopropyl alcohol, the liquid temperature was raised to 95 ° C. to prepare a reaction liquid. This reaction solution was transferred to an electromagnetic stirring autoclave, to which 10.2 g (0.17 mol) of acetic acid was added, and the reaction was performed at 160 ° C. for 3 hours while stirring.

  The reaction solution was cooled to 40 ° C. or lower to complete the reaction. The solid content concentration in the reaction solution was 4.8% by mass. As a result of observing the obtained alumina hydrate particles with a transmission electron microscope (TEM), they were fibrous particles having an average minor axis of 2 nm, an average major axis of 2000 nm, and an average aspect ratio of 1,000.

<Fibrous alumina-PVA resin composite film>
9.5 g of fibrous alumina particle dispersion shown in Reference Example and 0.36 g of 12.5% by mass polyvinyl alcohol (abbreviated as PVA, Kanto Chemical, average polymerization degree: 900 to 1100, complete saponification type) aqueous solution, It was put into a plastic container, vigorously shaken for 20 minutes, and deaerated with a centrifuge to obtain a uniform alumina-PVA dispersion. The mass ratio between the fibrous alumina particles and polyvinyl alcohol was 10/1.

  This uniform alumina-PVA dispersion was poured into a Teflon (registered trademark) -coated container (80 mm × 80 mm × 2 mm) and dried in a blown oven at 50 ° C. for 1 hour to obtain a length of 80 mm, a width of 80 mm, A uniform fibrous alumina-PVA composite membrane having a thickness of 50 μm was obtained. The crystal system of alumina was boehmite, and the peak (020) plane near 14.5 ° and the (120) plane peak intensity ratio near 28.5 ° were (020) / (120) = 8. The total light transmittance of this uniform fibrous alumina-PVA composite film was 90%.

(Comparative Example 1)
<Columnar alumina-PVA resin composite film>
The fibrous alumina particle dispersion was changed to 4.32 g of a columnar alumina particle (average minor axis: 10 nm, aspect ratio: 5) dispersion (dispersion medium: water, solid content: 10% by mass), and the same as in Example 1. Thus, a uniform columnar alumina-PVA dispersion was obtained. The mass ratio between the columnar alumina particles and polyvinyl alcohol was 0.432 / 0.045. Using this uniform columnar alumina-PVA dispersion, a film was formed in the same manner as in Example 1, but only a fragmented film was obtained.

<Alumina-sodium polyacrylate composite film>
10 g of fibrous alumina sol used in Example 1, 0.01 g of sodium polyacrylate (Wako Pure Chemical Industries, degree of polymerization: 22,000-70,000) and 5 g of ion-exchanged water are placed in a plastic container for 20 minutes. The mixture was vigorously shaken and degassed with a centrifugal separator to obtain a uniform alumina-sodium polyacrylate dispersion. The mass ratio of fibrous alumina particles to sodium polyacrylate was 48/1.

  This uniform alumina-sodium polyacrylate dispersion was poured into a Teflon (registered trademark) -coated container used in Example 1 and dried in a blowing oven at 40 ° C. for 3 hours to obtain a length of 80 mm, A uniform alumina-sodium acrylate composite film having a thickness of 80 mm and a thickness of 45 μm was obtained. The crystal system of alumina was boehmite, and the peak (020) plane near 14.5 ° and the (120) plane peak intensity ratio near 28.5 ° were (020) / (120) = 7. The uniform light transmittance of this uniform alumina-sodium acrylate composite film was 60%.

(Comparative Example 2)
<Alumina-sodium polyacrylate composite film>
4.8 g of columnar alumina sol used in Comparative Example 1, 0.01 g of sodium polyacrylate used in Example 2 and 10 g of ion-exchanged water are placed in a plastic container, shaken vigorously for 20 minutes, and removed with a centrifuge. As a result, a uniform alumina-sodium polyacrylate dispersion was obtained. The mass ratio between the columnar alumina particles and polyacrylic acid was 4.8 / 0.01. This uniform alumina-sodium polyacrylate dispersion was poured into a Teflon (registered trademark) -coated container (80 mm × 80 mm × 2 mm) and dried in a blown oven at 40 ° C. for 3 hours. Only obtained.

<Alumina-epoxy resin composite film>
11 g of fibrous alumina sol used in Example 1 and 9 g of ion-exchanged water were put in a plastic container, shaken vigorously for 20 minutes, and then deaerated with a centrifuge to obtain a uniform alumina dispersion. . This dispersion is poured into a Teflon (registered trademark) -coated container (80 mm × 80 mm × 10 mm) and dried in a blown oven at 40 ° C. for 3 hours to obtain a uniform 80 mm length, 80 mm width, 50 μm thickness. A porous alumina self-supporting membrane was obtained. Furthermore, the peeled self-supporting film was baked at 150 ° C. for 2 hours to obtain 0.60 g of an alumina porous dry self-supporting film.

  The resulting alumina porous self-supporting membrane was mixed with 1 g of an epoxy resin precursor (trademark: EPICLON EXA-4850-150, Dainippon Ink and Chemicals), 0.075 g of triethylenetetramine (Wako Pure Chemical Industries), and 20 g of toluene. After impregnating the solution for 30 minutes, the free-standing membrane is taken out from the mixed solution, and the free-standing membrane surface is washed with 50 ml of toluene and washed at 80 ° C. (3 hours) → temperature increase (1 hour) → 125 ° C. (2 hours) → Curing treatment was performed under conditions of temperature rise (1 hour) → 150 ° C. (2 hours) to obtain an alumina-epoxy resin composite film.

The mass ratio between the fibrous alumina particles and the epoxy resin was 0.60 / 0.09. The total light transmittance of this film was 92%. The (020) plane peak around 14.5 ° and the (120) plane peak intensity ratio around 28.5 ° were (020) / (120) = 20. Furthermore, as a result of measuring the linear thermal expansion coefficient, it was 11 * 10 <^-6> linear thermal expansion coefficient. As a result of evaluating the flexibility, the mandrel diameter was 15 mm.

(Comparative Example 3)
<Columnar alumina-epoxy resin composite film>
Fibrous alumina hydrate particles were changed to columnar alumina hydrate particles (alumina content: 68%, average minor axis: 10 nm, aspect ratio: 5), and addition amount of epoxy resin precursor was changed to 0.6 g. In the same manner as in Example 3, a uniform columnar alumina-epoxy resin dispersion was obtained. The mass ratio between the columnar alumina particles and the epoxy resin precursor was 2.04 / 0.6. This uniform columnar alumina-epoxy resin dispersion was formed in the same manner as in Example 3, but only a fragmented film was obtained.

<Alumina-polyvinylpyrrolidone composite film>
A uniform alumina-PVP dispersion was obtained in the same manner as in Example 2 except that sodium polyacrylate was changed to polyvinyl pyrrolidone (abbreviated as PVP, Wako Pure Chemical Industries, Ltd., trademark: polyvinyl pyrrolidone K30). By treating this dispersion in the same manner as in Example 2, a uniform alumina-PVP composite membrane having a length of 80 mm, a width of 80 mm, and a thickness of 45 μm was obtained. The total light transmittance of this composite film was 65%. The crystal system of alumina was boehmite, and the peak (020) plane near 14.5 ° and the (120) plane peak intensity ratio near 28.5 ° were (020) / (120) = 15.

<Alumina-polyethylene glycol composite membrane>
A uniform alumina-PEG dispersion was obtained in the same manner as in Example 2 except that sodium polyacrylate was changed to polyethylene glycol (abbreviated as PEG, Wako Pure Chemical Industries, average molecular weight: 2000). By treating this dispersion in the same manner as in Example 2, a uniform alumina-PEG composite film having a length of 80 mm, a width of 80 mm, and a thickness of 45 μm was obtained.

<Alumina-aluminum quinolinol complex composite film>
0.57 g of an alumina porous dry self-supporting membrane obtained in the same manner as in Example 3 was impregnated with 10 g of a 0.08 mass% toluene solution of tris (8-quinolinolato) aluminum (abbreviated as Alq3, manufactured by Aldrich) for 30 minutes. Then, an alumina-Alq3 composite film was obtained by drying under reduced pressure for 2 hours in a desiccator. The amount of Alq3 adsorbed on the porous alumina self-supporting membrane was 0.0035 g, and the mass ratio of alumina to Alq3 was 0.57 / 0.0035.

  When this alumina-Alq3 composite film was irradiated with ultraviolet rays having a wavelength of 254 nm, green light emission (peak wavelength: 500 nm) was observed. The crystal system of alumina was boehmite, and the peak (020) plane near 14.5 ° and the (120) plane peak intensity ratio near 28.5 ° were (020) / (120) = 15.

<Alumina-EL phosphor composite film>
0.67 g of an alumina porous dry self-supporting membrane obtained in the same manner as in Example 3 was added to tris (dibenzoylmethane) mono (1,10-phenanthroline) europium [abbreviated as Eu (phen) complex, manufactured by Aldrich]. A 10% 1% by weight toluene solution was impregnated for 30 minutes and treated in the same manner as in Example 6 to obtain an alumina-Eu (phen) complex composite membrane. The adsorption amount of the Eu (phen) complex to the alumina porous self-supporting membrane was 0.003 g, and the mass ratio of alumina to the Eu (phen) complex was 0.67 / 0.004.

  When this alumina-Eu (phen) complex composite film was irradiated with ultraviolet light having a wavelength of 254 nm, red light emission (peak wavelengths: 613, 410 nm) was observed.

<Alumina-EL phosphor composite film>
0.64 g of an alumina porous dry self-supporting membrane obtained in the same manner as in Example 3 was added to 15 g of a 0.5 mass% ethanol solution of N, N-bis (salicylidene) ethylenediamine (abbreviated as salen, manufactured by Aldrich). An alumina-salen composite membrane was obtained by impregnating for 5 minutes and treating in the same manner as in Example 6. The amount of salen adsorbed on the alumina porous self-supporting membrane was 0.005 g, and the mass ratio of alumina to salen was 0.64 / 0.005.

  When this alumina-salen composite film was irradiated with ultraviolet rays having a wavelength of 254 nm, blue light emission (peak wavelength: 470 nm) was observed.

<Alumina-glucoamylase composite membrane>
10 mg of the alumina porous dry self-supporting membrane obtained in the same manner as in Example 3 and 1 ml of an 8 mg / ml glucoamylase (GA) solution (Wako Pure Chemical Industries, 0077-0471, 10000 units, 11 units) were added at 4 ° C., Stir for 12 hours. Further, the resultant was centrifuged at 3000 rpm for 5 minutes, and the supernatant unadsorbed protein was measured by the BCA method. As a result, the adsorbed amount was 0.9 mg per 10 mg of alumina. Furthermore, it wash | cleaned 1-50 times with a 50 mM acetate buffer solution (pH5.5), the protein of the washing | cleaning liquid was measured by BCA method, the residual protein adsorption amount was computed, and it showed in following Table 1. Table 1 shows changes in the amount of GA adsorbed on the alumina self-supporting film by cleaning. The mass ratio of alumina and glucoamylase was 10 / 0.9 to 0.6, and further, immobilization on the alumina membrane could be confirmed.

  As a result of measuring the activity of glucoamylase adsorbed on alumina, it showed an activity equivalent to that of free glucoamylase.

<Alumina-urea composite membrane>
50 g of fibrous alumina particle dispersion (solid content: 4.8% by mass), 0.28 g of urea (Wako Pure Chemical Industries) and 50 g of ion-exchanged water obtained in the same manner as in the reference example were treated in the same manner as in Example 1. As a result, a uniform alumina-urea dispersion was obtained. The mass ratio between the fibrous alumina particles and urea was 2.4 / 0.28. This uniform alumina-urea dispersion is poured into a Teflon (registered trademark) -coated container (300 mm × 280 mm × 10 mm), and dried in a blown oven at 40 ° C. for 3 hours, to be 300 mm long, 280 mm wide, A uniform alumina-urea composite film having a thickness of 30 μm was obtained.

  The total light transmittance of this uniform alumina-urea composite film was 85%. The (020) plane peak near 14.5 ° and the (120) plane peak intensity ratio near 28.5 ° were (020) / (120) = 20.

<Alumina-deoxyribonucleic acid sodium composite film>
A uniform alumina-DNA dispersion was obtained in the same manner as in Example 10 except that urea was changed to 0.02 g of deoxyribonucleic acid (Wako Pure Chemical Industries). The weight ratio of fibrous alumina particles to deoxyribonucleic acid was 2.4 / 0.02. This uniform alumina-DNA dispersion was poured into a Teflon (registered trademark) -coated container (300 mm × 280 mm × 10 mm), and dried in a blown oven at 30 ° C. for 3 hours, whereby 300 mm in length, 280 mm in width, A uniform alumina-deoxyribonucleic acid composite film having a thickness of 30 μm was obtained.

  This uniform alumina-deoxyribonucleic acid composite film had a total light transmittance of 85%. The crystal system of alumina was boehmite, and the (020) plane peak intensity around 14.5 ° and the (120) plane peak intensity ratio near 28.5 ° were (020) / (120) = 20.

<Alumina-3-glycidoxypropyltrimethoxysilane composite film>
A uniform alumina-GPMS dispersion was obtained in the same manner as in Example 10, except that urea was changed to 0.05 g of 3-glycidoxypropyltrimethoxysilane (abbreviated as GPMS, Shin-Etsu Chemical Co., Ltd.). The mass ratio between the fibrous alumina particles and GPMS was 2.4 / 0.2. By treating this uniform alumina-GPMS dispersion in the same manner as in Example 12, a uniform alumina-GPMS composite film having a length of 300 mm, a width of 280 mm, and a thickness of 30 μm was obtained.

  The total light transmittance of this uniform alumina-GPMS composite film was 60%. The crystal system of alumina was boehmite, and the (020) plane peak intensity around 14.5 ° and the (120) plane peak intensity ratio near 28.5 ° were (020) / (120) = 5.

<Alumina-conductive polymer composite film>
Urea was changed to 1 g of a 5 mass% polypyrrole aqueous solution (Sigma Aldrich Japan) and treated in the same manner as in Example 10 without adding ion-exchanged water to obtain a uniform alumina-polypyrrole dispersion. The mass ratio between the fibrous alumina particles and the polypyrrole was 1.4 / 0.05. By treating the uniform alumina-polypyrrole dispersion in the same manner as in Example 11, a uniform alumina-polypyrrole composite film having a length of 300 mm, a width of 280 mm, and a thickness of 30 μm was obtained.

The total light transmittance of this uniform alumina-polypyrrole composite film was 40%. The intensity ratio of (020) plane peak near 14.5 ° and (120) plane peak near 28.5 ° was (020) / (120) = 15. Further, the surface resistivity of this composite film was measured and found to be 2.5 × 10 ⁴ Ω / □.

<Alumina-conductive polymer composite film>
Urea was changed to 0.1 g of polyaniline (Sigma Aldrich Japan) and treated in the same manner as in Example 10 without adding ion-exchanged water to obtain a uniform alumina-polyaniline dispersion. The mass ratio between the fibrous alumina particles and the polypyrrole was 1.4 / 0.1. By treating this uniform alumina-polyaniline dispersion in the same manner as in Example 10, a uniform alumina-polyaniline composite film having a length of 300 mm, a width of 280 mm, and a thickness of 30 μm was obtained.

The total light transmittance of this uniform alumina-polyaniline composite film was 40%. The (020) plane peak around 14.5 ° and the (120) plane peak intensity ratio around 28.5 ° were (020) / (120) = 20. Further, the surface resistivity of this composite film was measured and found to be 3.7 × 10 ⁴ Ω / □.

  As described above in detail, the present invention relates to an organic alumina composite thin film and a method for producing the same, and according to the present invention, particles or pores are highly oriented at the molecular level, and furthermore, strength that can be used independently. It is possible to provide an organic alumina composite thin film including According to the present invention, an alumina organic composite thin film having various functions such as light emission, polarization, refraction, and conductivity can be obtained on various supports. Further, according to the present invention, there is provided an organic alumina composite thin film having sufficient strength that can be used as a self-supporting film, flexible, free from cracks, highly transparent, and having various functions. can get. The organic-alumina composite thin film of the present invention is an organic-alumina composite thin film based on alumina, and has an excellent thermal stability, thermal conductivity, electrical insulation, etc. according to the organic material to be selected. It is useful for providing new materials such as devices, separation membranes, photoelectrochemical membranes, and ion conductive membranes.

Claims (16)

  The aspect ratio (major axis / minor axis) is 30 to 5,000, and consists of alumina hydrate particles or alumina particles having a fibrous or needle-like shape, and an accumulation of organic matter. The alumina hydrate particles or alumina particles are Apparently, it is an organic alumina composite thin film that is a host, and the total amount of the organic matter is 30% or less by weight with respect to the alumina composite thin film, and those aluminas have orientation. An organic alumina composite thin film characterized by having a support or peeling from the support.   The organic alumina composite thin film according to claim 1, wherein the organic alumina composite thin film exhibits flexibility in a state where the organic alumina composite thin film is peeled off from the support.   The organic alumina composite thin film according to claim 1 or 2, wherein the alumina hydrate particles are at least one selected from amorphous, boehmite, and pseudoboehmite.   The organic alumina composite thin film according to claim 1 or 2, wherein the crystal system of the alumina particles is at least one selected from γ, θ, or α.   The organic alumina composite thin film according to claim 1 or 2, wherein the organic substance has a boiling point of at least 40 ° C.   The organic alumina composite thin film according to any one of claims 1 to 5, wherein the thickness of the organic alumina composite thin film is more than 0 to 1000 µm.   The organic alumina composite thin film according to any one of claims 1 to 6, wherein the alumina hydrate particles or alumina particles have a minor axis of 1 to 10 nm and a major axis of 100 to 10,000 nm.   The organic alumina composite thin film according to any one of claims 1 to 7, wherein the aspect ratio of the alumina hydrate particles or the alumina particles is 100 to 3000.   The organic alumina composite thin film according to any one of claims 1 to 8, wherein a major axis of the alumina hydrate particles or alumina particles is 700 to 7000 nm.   An aggregate of at least one kind of alumina hydrate particles selected from boehmite or pseudoboehmite is an organic alumina composite thin film that apparently becomes an organic host, and a crystallite based on alumina particles in X-ray diffraction The organic-alumina composite thin film according to any one of claims 1 to 9, having crystal orientation in which a diffraction intensity ratio d (020) / (120) between the plane (020) and the crystallite plane (120) is 5 or more.   An aggregate of at least one kind of alumina particles selected from amorphous, boehmite, pseudoboehmite, γ-alumina, or θ-alumina is an organic alumina composite thin film that apparently becomes an organic host, and its flexibility However, when a bending resistance test based on JIS K5600-5-1 is performed at a film thickness of 100 μm or less immediately after peeling from the support, the occurrence of cracks is observed when the diameter of the cylindrical mandrel is 2 mm or more. The organic-alumina composite thin film according to any one of claims 2 to 10, which has no characteristics.   The organic alumina composite thin film according to claim 11, wherein the organic alumina composite thin film has a thermal conductivity of 0.1 to 10 W / mK.   The organic-alumina composite thin film according to claim 12, wherein the organic-alumina composite thin film has a film thickness of 0.1 to 100 µm and a total light transmittance of 20% or more.   A method for producing the organic alumina composite thin film according to any one of claims 1 to 10, wherein the minor axis is 2 to 5 nm, the major axis is 100 to 10,000 nm, and the fiber is an aspect ratio of 30 to 5,000. A method for producing an organic alumina composite thin film, which comprises applying an aqueous alumina sol in which acicular alumina hydrate particles are dispersed to a support or an object and drying.   The method for producing an organic alumina composite thin film according to claim 14, wherein the alumina hydrate particles are at least one selected from boehmite or pseudoboehmite.   The method for producing an organic alumina composite thin film according to claim 14 or 15, wherein the alumina sol is obtained by hydrolyzing and peptizing aluminum alkoxide.