JPH11310411A - Production of organic-inorganic composite and porous silicon oxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a composite material from an organic polymer and a silicon oxide, with excellent mechanical strength and solvent resistance, and to provide a method for producing a porous silicon oxide of high porosity. SOLUTION: This method for producing an organic-inorganic composite comprises mixing an alkoxysilane with an organic polymer bearing at least one polymerizable functional group in one molecule followed by carrying out hydrolysis/dehydrocondensation reaction of the alkoxysilane and polymerization reaction using the functional groups in the organic polymer. Another method for producing a porous silicon oxide comprises removing the organic polymer from the organic-inorganic composite obtained above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an organic-inorganic composite which is a composite material of an organic polymer and a silicon oxide, and a method for producing a porous silicon oxide having a large porosity.

[0002]

2. Description of the Related Art In recent years, organic-inorganic composites in which various organic polymers are dispersed in silicon oxide have been studied for the purpose of improving characteristics such as mechanical strength. For example, Journal of Macromolecul
ar Science-Chemistry, A27,
13-14 p. 1603 (1990) describes a complex of a polymer containing an amide bond such as polyoxazoline and a silicon oxide. In addition, Report
ts on Progress in Polymer
Physics in Japan, Vol. 38
P. 315 (1995), polyvinylidene fluoride,
Journal of Polymers, Vol. 53, No. 4, p. 218
(1996) polyvinyl alcohol, Macro
moleculars, 26 p. 3702 (1993
Year) is polyvinyl acetate, Polymer, 33 (7)
P. 1486 (1992) discusses a composite material with a silicon oxide using various organic polymers such as polymethyl methacrylate.

However, the organic polymers used as raw materials for the production of these composites are linear polymers having a limited molecular weight or spherical starburst dendrimers, so that the mechanical strength of the obtained composites is high. In addition, the organic polymer is dissolved when it comes into contact with a solvent in which the organic polymer dissolves, so that there is also a problem with the solvent resistance of the composite. Further, when an organic polymer is removed from these composites to obtain a porous silicon oxide, there is a problem that remarkable shrinkage occurs and voids are easily crushed.

Japanese Patent Application Laid-Open No. 8-157735 and the like describe a method for producing a composite of a silicon oxide and an organic polymer using a polymerizable organic monomer as a starting material. When this method is used, a complex having a structure in which a three-dimensional network structure of a silicon oxide and a three-dimensional network structure of an organic polymer are entangled with each other by using a bifunctional monomer as a polymerizable organic monomer. You can also get. Further, studies have been made to obtain a porous silicon oxide by removing an organic polymer from the above-mentioned various composite materials. However, when a polymerizable organic monomer is used as a starting material, the viscosity of the mixture is low,
Further, since the monomer is evaporated at the gelation stage, there is a problem that it is difficult to form a coating film or a fibrous shape.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a method for producing a composite material of an organic polymer and a silicon oxide having excellent mechanical strength and solvent resistance, and a method for producing a porous silicon oxide having a large porosity. It is intended to provide a manufacturing method.

[0006]

Means for Solving the Problems In order to solve the above problems, the present inventors have conducted intensive studies, and as a result, using an organic polymer having a polymerizable functional group in a molecule and an alkoxysilane as raw materials, By reacting the polymerizable functional groups in the polymer before or after or simultaneously with the formation of the silicon oxide by the gelation of the silane, an organic-inorganic composite having uniform transparency and excellent mechanical strength and solvent resistance can be obtained. Further, it has been found that by removing the organic polymer from the organic-inorganic composite, a porous silicon oxide having a large surface area and a high porosity can be obtained, and the present invention has been accomplished.

That is, the present invention provides (1) a method of mixing an alkoxysilane and an organic polymer having at least one polymerizable functional group in a molecule, and carrying out a hydrolysis / dehydration condensation reaction of the alkoxysilane, A method for producing an organic-inorganic composite, comprising performing a polymerization reaction using a functional group contained in a polymer; (2) an organic polymer having a polymerizable functional group is an aliphatic polyether or an aliphatic polyester; (1) The method for producing an organic-inorganic composite according to (1), which is a polymer containing aliphatic polycarbonate or aliphatic polyanhydride as a main component.
(3) An organic-inorganic composite obtained by the method for producing an organic-inorganic composite according to (1) or (2), (4)
(3) A method for producing a porous silicon oxide, comprising removing an organic polymer from the organic-inorganic composite according to (3), (5) A porous silicon oxide obtained by the production method according to (4). ,.

Hereinafter, the present invention will be described in detail. The method for producing an organic-inorganic composite of the present invention comprises mixing an alkoxysilane and an organic polymer having at least one polymerizable functional group in a molecule, and hydrolyzing and dehydrating the alkoxysilane. Polymerizing a polymerizable functional group contained in the organic polymer. By performing these steps, the alkoxy group contained in the alkoxysilanes becomes a hydroxyl group, and subsequently undergoes a dehydration condensation reaction to gel, while the organic polymer has a three-dimensional network structure and / or a graft structure.

The alkoxysilanes usable in the present invention include tetramethoxysilane, tetraethoxysilane, tetra (n-propoxy) silane, tetra (i-propoxy) silane, tetra (n-butoxy)
Examples include silane and tetraalkoxysilane such as tetra (t-butoxy) silane. Oligomers of alkoxysilane, trimethoxysilane, triethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, bis (trimethoxysilyl) methane,
Bis (triethoxysilyl) methane, 1,2-bis (trimethoxysilyl) ethane, 1,2-bis (triethoxysilyl) ethane, 1,4-bis (trimethoxysilyl) benzene, 1,4-bis ( An alkoxysilane having one hydrogen, an alkyl group or an aryl group on a silicon atom, such as triethoxysilyl) benzene, is also included in the alkoxysilanes used in the present invention. A partially hydrolyzed product of alkoxysilanes may be used as a raw material. These may be used alone or in combination of two or more.

Further, in order to modify the resulting composite or porous silicon oxide, an alkoxysilane having 2 to 3 hydrogen, alkyl or aryl groups on a silicon atom is mixed with the above alkoxysilanes. It is also possible. The mixing amount is set to be 80% or less of the total number of moles of the raw material silane compound. If it exceeds 80%, gelation may not occur.

The major feature of the present invention is to use an organic polymer having at least one polymerizable functional group in the molecule. If the organic polymer has at least one polymerizable functional group in the molecular chain,
Without special limitation, specific examples include polyether,
Polyester, polycarbonate, polyanhydride, polyamide, polyurethane, polyurea, polyacrylic acid, polyacrylate, polymethacrylic acid,
Polymethacrylate, polyacrylamide, polymethacrylamide, polyacrylonitrile, polymethacrylonitrile, polyolefin, polydiene, polyvinyl ether, polyvinyl ketone, polyvinylamide, polyvinylamine, polyvinyl ester, polyvinyl alcohol, polyvinyl halide, polyhalogenation Examples include polymers having vinylidene, polystyrene, polysiloxane, polysulfide, polysulfone, polyimine, polyimide, cellulose, and derivatives thereof as main components. Copolymers of monomers that are constituent units of these polymers or copolymers with any other monomer may be used. One or more organic polymers may be used in combination. The polymerization degree of the polymer is selected from 8 to 350,000.

Among the above-mentioned polymers, those preferably used are polyethers, polyesters, polycarbonates, polyanhydrides, polyamides, polyurethanes, polyureas, polyacrylic acids, polyacrylic esters, polymethacrylic acids, polymethacrylic esters,
Polyacrylamide, polymethacrylamide, polyvinylamide, polyvinylamine, polyvinylester, polyvinyl alcohol, polyimine, and polyimide are used as main components. Furthermore, when converted to porous silicon oxide by heating and sintering as described below, aliphatic polyethers having a low thermal decomposition temperature, aliphatic polyesters, aliphatic polycarbonates, and aliphatic polyanhydrides are the main components. It is particularly preferred to use one.

The polymerizable functional groups include vinyl, vinylidene, vinylene, glycidyl, allyl, acrylate, methacrylate, acrylamide, methacrylamide, carboxyl, hydroxyl,
Examples include an isocyanate group, an amino group, an imino group, and a halogen group. These functional groups may be in the main chain, at the terminal, or in the side chain of the polymer. Further, it may be directly bonded to the polymer chain, or may be bonded via a spacer such as an alkylene group or an ether group. The same polymer molecule may have one type of functional group, or may have two or more types of functional groups. Among the functional groups listed above, vinyl, vinylidene, vinylene, glycidyl, allyl, acrylate, methacrylate, acrylamide, and methacrylamide groups are preferably used.

Specific examples of the basic skeleton of the organic polymer which can be suitably used for producing the organic-inorganic composite of the present invention are shown below. Hereinafter, alkylene refers to methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, isopropylidene, 1,2-dimethylethylene, 2,2-dimethyltrimethylene, and alkyl refers to C1 to C8. Alkyl group and aryl group such as phenyl group, tolyl group and anisyl group. (Meth) acrylate refers to both acrylate and methacrylate. Dicarboxylic acid refers to oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid. , Pimelic acid, suberic acid, azelaic acid, and sebacic acid.

Polyalkylene glycol (meth) acrylate, polyalkylene glycol di (meth) acrylate, polyalkylene glycol alkyl ether (meth) acrylate, polyalkylene glycol vinyl ether, polyalkylene glycol divinyl ether, polyalkylene glycol alkyl ether vinyl ether, polyalkylene Glycol glycidyl ether, polyalkylene glycol diglycidyl ether,
An aliphatic polyether having a polymerizable functional group such as an acrylate group, a methacrylate group, a vinyl group, or a glycidyl group at a terminal, such as a polyalkylene glycol alkyl ether glycidyl ether.

Polycaprolactone (meth) acrylate, polycaprolactone vinyl ether, polycaprolactone glycidyl ether, polycaprolactone vinyl ester, polycaprolactone glycidyl ester, polycaprolactone vinyl ester (meth) acrylate, polycaprolactone glycidyl ester (meth) acrylate, polycaprolactone vinyl Polymerizable acrylate group, methacrylate group, vinyl group, glycidyl group, etc. at one or both ends represented by ester vinyl ether, polycaprolactone glycidyl ester vinyl ether, polycaprolactone vinyl ester glycidyl ether, polycaprolactone glycidyl ester glycidyl ether, etc. Polycaprolactone with various functional groups.

(Meth) acrylate, di (meth) acrylate, tri (meth) acrylate, vinyl ether, divinyl ether, trivinyl ether, glycidyl ether, diglycidyl ether, triglycidyl ether of polycaprolactone triol. An aliphatic polyester that is a polymer of a dicarboxylic acid and an alkylene glycol and has a polymerizable functional group such as an acrylate group, a methacrylate group, a vinyl group, or a glycidyl group at one or both ends.

An aliphatic polyalkylene carbonate having a polymerizable functional group such as an acrylate group, a methacrylate group, a vinyl group and a glycidyl group at one or both terminals. An aliphatic polyanhydride which is a polymer of a dicarboxylic anhydride and has a polymerizable functional group such as an acrylate group, a methacrylate group, a vinyl group, or a glycidyl group at a terminal.

Polyglycidyl (meth) acrylate,
Polyallyl (meth) acrylate, polyvinyl (meth)
Polyacrylates and polymethacrylates having functional groups such as vinyl group, glycidyl group and allyl group in side chains such as acrylate. Polyvinyl cinnamate, polyvinyl azidobenzal, epoxy resin, etc. Among these, the aliphatic polyethers, aliphatic polyesters, and fatty acids shown above to which a transparent homogeneous composite is easily obtained, and which can be easily converted to a porous silicon oxide by heating and sintering as described below. Aromatic polycarbonates, aliphatic polyanhydrides and the like are particularly preferably used.

The amount of the organic polymer to be added in the production of the organic-inorganic composite of the present invention is 10 ^{-2 to} 100 parts by weight, preferably 10 ^-1 to 10 parts by weight based on 1 part by weight of the alkoxysilane.
Parts by weight, more preferably 10 ^{-1 to} 5 parts by weight. Even if the amount of the organic polymer added is less than 10 ^-2 parts by weight,
If the amount is more than 00 parts by weight, the properties of the composite do not appear and the utility is poor.

Further, in order to modify the organic-inorganic composite, it is possible to add a polymerizable monomer or a polymer thereof. Acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester, ethylene bis acrylate, ethylene bis methacrylate, α-cyanoacrylic acid, acrylic acid and methacrylic acid derivatives such as α-cyanoacrylic acid ester, and acetic acid can be used. Acid vinyl esters such as vinyl, vinyl propionate, vinyl crotonate, vinyl benzoate, vinyl chloroformate, acrylamide, methacrylamide, N, N-dialkylacrylamide, N, N-dialkylmethacrylamide, N-alkylacrylamide, N Amides such as -alkyl methacrylamide, N, N'-methylenebisacrylamide, N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, styrene, α-methylstyrene, p-method Vinyl group-containing hydrocarbons such as xylstyrene, diphenylethylene, vinylnaphthalene, vinylanthracene, vinylcyclopentane, vinylcyclohexane, and 5-vinyl-2-norbornene; acrylonitrile derivatives such as acrylonitrile and methacrylonitrile; N-vinylpyridine; -Vinylamines such as vinylcarbazole and N-vinylimidazole, vinylalkyl ethers, vinylalkylketones, glycidyl acrylate, glycidyl methacrylate, epoxy resins, and polymers thereof.

In the production of the organic-inorganic composite of the present invention, the presence of a solvent is not always essential. However, in general, the alkoxysilanes and the organic polymer are hardly compatible with each other. It is necessary. Any solvent can be used without particular limitation as long as it can dissolve both the alkoxysilanes and the organic polymer. Even if the starting alkoxysilanes are insoluble, they can be used in the same manner as long as they become soluble after hydrolysis. The amount of the solvent used is such that the total concentration of the alkoxysilane, the organic polymer, and the organic monomer is 0.05% by weight or more. At a concentration lower than this, gelation does not occur, and a practical coating film cannot be obtained.

Examples of the solvent used include monohydric alcohols of C1 to C4, dihydric alcohols of C1 to C4, alcohols such as glycerin, formamide, N-methylformamide, N-ethylformamide, N, N- Dimethylformamide, N, N-diethylformamide,
N-methylacetamide, N-ethylacetamide,
N, N-dimethylacetamide, N, N-diethylacetamide, N-methylpyrrolidone, N-formylmorpholine, N-acetylmorpholine, N-formylpiperidine, N-acetylpiperidine, N-formylpyrrolidine, N-acetylpyrrolidine, N Amides such as N, N'-diformylpiperazine and N, N'-diacetylpiperazine, ureas such as tetramethylurea and N, N'-dimethylimidazolidinone, tetrahydrofuran, diethyl ether and di (n-propyl) ether , Diisopropyl ether, diglyme, 1,4-dioxane, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl Ethers such as ether,
Esters such as ethyl formate, methyl acetate, ethyl acetate, ethyl lactate, ethylene glycol monomethyl ether acetate, ethylene glycol diacetate, propylene glycol monomethyl ether acetate, diethyl carbonate, ethylene carbonate, propylene carbonate, acetone, methyl ethyl ketone, methyl propyl ketone, Methyl (n
-Butyl) ketone, methyl isobutyl ketone, methyl amyl ketone, ketones such as cyclopentanone, cyclohexanone, acetonitrile, propionitrile, n-
Nitriles such as butyronitrile and isobutyronitrile, dimethylsulfoxide, dimethylsulfone, and sulfolane are preferably used. These solvents may be mixed, or any other solvent or additive may be mixed.

Among the solvents listed above, formamide,
N-methylformamide, N-ethylformamide,
N, N-dimethylformamide, N, N-diethylformamide, N-methylacetamide, N-ethylacetamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methylpyrrolidone, N-formylmorpholine, N- Amides such as acetylmorpholine, N-formylpiperidine, N-acetylpiperidine, N-formylpyrrolidine, N-acetylpyrrolidine, N, N′-diformylpiperazine, N, N′-diacetylpiperazine, tetramethylurea, It is particularly preferable to use ureas such as N'-dimethylimidazolidinone.

In the present invention, a catalyst is not necessarily required for the hydrolysis and dehydration condensation reaction of alkoxysilane,
A catalyst may be added to promote the reaction. Specific examples of the catalyst include hydrochloric acid, nitric acid, sulfuric acid, formic acid, acetic acid, oxalic acid, acids such as maleic acid, aqueous ammonia, potassium hydroxide,
Examples include alkalis such as sodium hydroxide, triethylamine, triethanolamine, pyridine, piperidine, choline and the like. These may be used alone or in combination of two or more. It is also possible to use two or more kinds in a stepwise manner. The term "stepwise" as used herein refers to, for example, treating with an acid catalyst before adding a base catalyst or vice versa.

The addition amount of these catalysts is 1 mol or less, preferably 10 ^-1 mol or less, per 1 mol of alkoxysilane. If it is more than 1 mol, a precipitate may be formed, and a uniform porous body may not be obtained. In the present invention, when these catalysts are aqueous solutions, the hydrolysis of the alkoxysilanes is caused by water, which is a solvent, and if there is sufficient water vapor in the surroundings without adding water, the hydrolysis is carried out. Can also be used. If necessary, water may be separately added. The appropriate amount of water is 0.3 to 10 ⁴ mol, preferably 1 to 10 mol, per 1 mol of silicon atoms contained in the starting alkoxysilane. If the amount is more than 10 ⁴ mol, the homogeneity of the obtained composite may decrease.

In producing the organic-inorganic composite of the present invention,
The hydrolysis / dehydration condensation reaction (gelation reaction) and the polymerization reaction
An organic-inorganic composite having the desired shape can be obtained by placing the film in a mold having an arbitrary shape, and an organic-inorganic composite thin film can be obtained by coating the substrate on a substrate. As a method of applying the film, a known method such as casting, rotation, and immersion can be used. The thickness of the thin film made of the organic-inorganic composite material is in the range of 0.1 μm to 10 μm. 10 μm
If it is thicker, cracks may occur.

The surface of the substrate may be treated in advance with an adhesion improver. In this case, as the adhesion improver, those used as a so-called silane coupling agent, an aluminum chelate compound, or the like can be used. Particularly preferably used are 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl)- 3-aminopropylmethyldimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropylmethyldichlorosilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropylmethyldiethoxysilane, 3
-Mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, hexamethyldisilazane, Ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate), aluminum bis (ethyl acetoacetate) monoacetylacetonate, aluminum tris (acetylacetonate) and the like. When applying these adhesion improvers, other additives may be added as necessary or diluted with a solvent before use. The treatment with the adhesion improver is performed by a known method.

The temperature of the gelation reaction is not particularly limited, but is usually 0 to 180 ° C., preferably 30 to 150 ° C.
Perform in the range of ° C. If it is too low, the reaction rate is low, and it takes a long time to crosslink sufficiently. On the other hand, if it is too high, voids are apt to be generated, and the homogeneity of the obtained organic-inorganic composite decreases. The time required for gelation varies depending on the gelling temperature, the amount of catalyst, and the like, but is usually in the range of several minutes to several days.

In the production of the organic-inorganic composite of the present invention, both the gelling reaction of alkoxysilane and the polymerization reaction using the functional group contained in the organic polymer occur.
This is the most characteristic part of the present invention. Either of these reactions may proceed first or may occur simultaneously. The order of these reactions varies depending on the type and amount of the catalyst and the reaction conditions. The polymerization reaction using a functional group here refers to a general addition, polyaddition, addition condensation, ring opening, polycondensation reaction and the like, and does not include a reversible photodimerization reaction.

The polymerization reaction using the functional group in the organic polymer can be accelerated by heating. The temperature ranges from 20 to 200 ° C. depending on the type of the functional group contained in the organic polymer.
Is selected from the range. In addition, if the organic polymer used is a photocrosslinkable one, the reaction can be advanced by light irradiation. A polymerization initiator may be added in order to promptly advance the polymerization reaction. Known polymerization initiators include thermal radical generators such as azo compounds and organic peroxides, photoacid generators such as diazo compounds, azide compounds, and acetophenone derivatives, as well as photoacid generators and photobase generators. Can be used. These may be used alone or in combination of two or more. Thermal polymerization and photopolymerization using an initiator are performed by a known method. The polymerization initiator is used in an amount of 10 ^-3 to 1 part by weight, preferably 10 ^-2 to 10 ^-1 part by weight, based on 1 part by weight of the organic polymer.

In the production of the organic-inorganic composite of the present invention, when the gelling reaction of the alkoxysilane and the polymerization reaction using the functional group of the organic polymer are carried out in the presence of a solvent and in a closed system, Thus, it is necessary to remove the solvent and dry the resulting mixture.
The drying temperature naturally depends on the type of the solvent, but is usually 30.
Perform in the range of ２５０250 ° C. Drying under reduced pressure is also effective. In order to control the generation of voids and obtain a uniform dried gel, a method of gradually increasing the temperature during the drying step is also preferable.

When the present invention is carried out in an open system using a solvent, evaporation of the solvent occurs in parallel with the above-mentioned gelling reaction of alkoxysilane and polymerization reaction using a functional group of an organic polymer. Controlling the order of reaction and solvent removal depends on the type of raw material silane compound, the type of functional group contained in the organic polymer, the type and amount of catalyst, the vapor pressure of the solvent, the atmosphere such as closed or open system, etc. It is possible by selecting. When the composite of the present invention is obtained in the form of a thin film, the solvent is removed when the gelling reaction of the alkoxysilane and the reaction of the functional group of the organic polymer are completed under ordinary conditions.

The composite obtained by the method of the present invention has a high mechanical strength, and the organic polymer no longer dissolves even when it comes into contact with a solvent that dissolves the organic polymer used. It has excellent properties not found in organic-inorganic composites. In addition, a composite having an arbitrary shape such as a coating film can be easily formed.

By removing only the organic polymer from the composite, it can be converted to a porous silicon oxide. The simplest method for removing the organic polymer is 1 minute to 2 minutes at or above the thermal decomposition temperature of the organic polymer.
This is a method of heating for about 4 hours. In addition, the organic polymer can be removed by plasma treatment. It is also effective to treat the obtained porous silicon oxide with a silylating agent to suppress water absorption and to improve the adhesion to other substances. Examples of silylating agents that can be used include trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethylethoxysilane, methyldiethoxysilane, dimethylvinylmethoxysilane , Dimethylvinylethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltrimethoxysilane,
Alkoxysilanes such as phenyltriethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, methyldichlorosilane,
Dimethylchlorosilane, dimethylvinylchlorosilane,
Methylvinyldichlorosilane, methylchlorodisilane,
Chlorosilanes such as triphenylchlorosilane, methyldiphenylchlorosilane and diphenyldichlorosilane, hexamethyldisilazane, N, N'-bis (trimethylsilyl) urea, N-trimethylsilylacetamide, dimethyltrimethylsilylamine, diethyltriethylsilylamine, trimethylsilylimidazole and the like Silazane and the like. The silylation method is performed by a method such as coating, dipping, and steam exposure.

Conventionally, a composite material of a linear organic polymer having a limited molecular weight or a spherical starburst dendrimer and a silicon oxide is heated and calcined to decompose and remove the organic polymer to obtain a porous silicon oxide. Examples were known. However, when heated, the silicon oxide is further dehydrated and condensed and tries to shrink, and at that time, the organic polymer in the molten state easily oozes out of the composite, so that the volume shrinks significantly due to firing and the large voids It was difficult to obtain a porous body having a high modulus.

The organic-inorganic composite of the present invention has a small amount of organic polymer bleeding even when heated and fired, and as a result, a porous silicon oxide having a porosity as large as 95% by volume can be easily obtained. Can be. Since the composite of the silicon oxide and the organic polymer of the present invention is excellent in mechanical strength and solvent resistance, an optical material such as a lens, a structural material, a film, a coating material, a substrate for an LSI multilayer wiring, It can be used for a wide range of applications such as semiconductor devices. In addition, the porous silicon oxide obtained from this composite has a larger surface area and porosity than conventional ones, so that it can be used as a catalyst carrier and has a low dielectric constant by forming a coating film. LS as insulating film
It is also possible to use it for an I multilayer wiring substrate or a semiconductor element.

[0038]

Embodiments of the present invention will be described below. The evaluation of the composite and the porous silicon oxide was performed using the following apparatus. (1) Surface area measurement (N2BET): A nitrogen adsorption type surface area measurement device manufactured by Shimadzu Corporation was used. (2) Film thickness measurement: DEKTAK-IIA manufactured by Sloan
A mold surface roughness measuring device was used. (3) Permittivity measurement: HP manufactured by Hewlett-Packard Company
A 4280 type CV measuring device was used. (4) Transparency: The composite was sliced to a thickness of 1 mm, placed on a dial with 3 mm square black characters written on a white background, and judged to be transparent if the characters could be read through the composite.

[0039]

Example 1 1.2 g of tetraethoxysilane, polyethylene glycol monomethacrylate (average molecular weight 36
0) 0.68 g was dissolved in a mixed solvent of 2.0 g of N-methylpyrrolidone and 1.0 g of propylene glycol methyl ether acetate, and 0.75 g of water and 0.1 N
0.15 g of nitric acid was added, and the mixture was stirred at room temperature for 2 hours. To this solution was added 0.03 g of dicumyl peroxide, cast on a polytetrafluoroethylene watch glass, and allowed to stand at 120 ° C. for 1 hour, whereupon the solution gelled. One more
By leaving at 80 ° C. for 1 hour, a glassy brown transparent composite was obtained. A 20-gram weight was applied to the composite with a cutter knife blade, but no damage was found.

[0040]

Example 2 1.2 g of tetraethoxysilane, polyethylene glycol monomethacrylate (average molecular weight 36
0) 0.68 g and 0.34 g of polyethylene glycol dimethacrylate (average molecular weight 540) were dissolved in a mixed solvent of 2.0 g of N-methylpyrrolidone and 1.0 g of propylene glycol methyl ether acetate, and 0.75 g of water was added to this solution. Add 0.15 g of 0.1N nitric acid and add
Stirred for hours. To this solution was added dicumyl peroxide 0.1.
When 05 g was added, the solution was cast on a polytetrafluoroethylene watch glass and left at 120 ° C. for 1 hour, and the solution gelled. Further, the mixture was left at 180 ° C. for 1 hour to obtain a glassy brown transparent composite. In this composite, the blade of the cutter knife is set up in the same manner as in Example 1, and 2
A weight of 0 grams was applied, but no damage was found.

[0041]

Example 3 0.92 g of methyltriethoxysilane, 0.68 g of polyethylene glycol monomethacrylate (average molecular weight: 360), 0.34 g of polyethylene glycol dimethacrylate (average molecular weight: 540), 2.0 g of N-methylpyrrolidone, propylene glycol methyl It was dissolved in a mixed solvent of 1.0 g of ether acetate, and 0.75 g of water and 0.15 g of 0.1 N nitric acid were added to this solution, followed by stirring at room temperature for 2 hours. To this solution was added 0.05 g of dicumyl peroxide, cast on a polytetrafluoroethylene watch glass and allowed to stand at 120 ° C. for 1 hour, whereupon the solution gelled. Further, the mixture was left at 180 ° C. for 1 hour to obtain a glassy brown transparent composite. The composite was loaded with a blade of a cutter knife in the same manner as in Example 1 and a weight of 20 grams was applied, but no damage was found.

[0042]

Example 4 0.60 g of tetraethoxysilane, 0.46 g of methyltriethoxysilane, 0.68 of polyethylene glycol monomethacrylate (average molecular weight: 360)
g, polyethylene glycol dimethacrylate (average molecular weight: 540) 0.34 g was added to N-methylpyrrolidone 2.0
g of propylene glycol methyl ether acetate in a mixed solvent of 1.0 g.
g and 0.15 g of 0.1 N nitric acid were added, and the mixture was stirred at room temperature for 2 hours. 0.05 g of dicumyl peroxide was added to this solution.
Was added, cast on a polytetrafluoroethylene watch glass, and allowed to stand at 120 ° C. for 1 hour, whereupon the solution gelled. Further, the mixture was left at 180 ° C. for 1 hour to obtain a glassy brown transparent composite. The composite was loaded with a blade of a cutter knife in the same manner as in Example 1 and a weight of 20 grams was applied, but no damage was found.

[0043]

Example 5 1.2 g of tetraethoxysilane, polyethylene glycol monomethacrylate (average molecular weight 36
0) 0.68 g and 0.34 g of polyethylene glycol dimethacrylate (average molecular weight 540) in ethanol 3.
The solution was dissolved in 0 g, and 0.75 g of water and 0.15 g of 0.1 N nitric acid were added to the solution, followed by stirring at room temperature for 2 hours. To this solution was added 0.05 g of dicumyl peroxide, and PTFE was added.
When the solution was cast on a watch glass and left at 120 ° C. for 1 hour, the solution gelled. The mixture was further left at 180 ° C. for 1 hour to obtain a glassy colorless and transparent composite. The composite was loaded with a blade of a cutter knife in the same manner as in Example 1 and a weight of 20 grams was applied, but no damage was found.

[0044]

Example 6 The composite obtained in Example 5 was treated with 60
The mixture was heated and baked at 0 ° C. for 1 hour to burn off the organic polymer and convert it to porous silicon oxide. The specific surface area of this porous silicon oxide was 874.9 m ² / g.

[0045]

Example 7 The composites obtained in Examples 1 to 5 were left immersed in water for 1 hour, but no weight reduction was observed.

[0046]

Example 8 The solution used in Example 2 was spin-coated on a silicon wafer at a rate of 1500 revolutions per minute and heated at 120 ° C. for 1 hour and at 180 ° C. for 1 hour to obtain a thickness of 0.41 μm.
m was obtained. This sample was placed under a nitrogen atmosphere for 45 minutes.
It was baked at 0 ° C. for 1 hour to burn off the organic polymer and convert it to porous silicon oxide. The film thickness at this time is 0.3
The thickness was 2 μm, and the reduction in film thickness compared to before firing was only 22%.

[0047]

Embodiment 9 The solution used in Embodiment 2 was spin-coated on a silicon wafer with a titanium nitride thin film at a speed of 1500 revolutions per minute, and heated at 120 ° C. for 1 hour and at 180 ° C. for 1 hour. It was baked at 450 ° C. for 1 hour in a nitrogen atmosphere to burn off the organic polymer and convert it to porous silicon oxide.
The film thickness was 0.27 μm. This sample was immersed in a 10% toluene solution of hexamethyldisilazane for 1 hour, and then dried at 120 ° C. under vacuum to modify the pore surface with a trimethylsilyl group to make it hydrophobic. Aluminum was deposited on the top of this thin film through a mask and had a diameter of 1.7.
mm electrode was produced. Using this sample, the relative dielectric constant of the porous silicon oxide thin film at 1 MHz was measured and found to be 2.17.

[0048]

EXAMPLE 10 A sample was prepared by adding 10% of hexamethyldisilazane.
Instead of immersing the sample in a toluene solution for 1 hour, place the sample in a sealed container with a petri dish containing hexamethyldisilazane and leave it at room temperature for 3 hours to expose it to the vapor of hexamethyldisilazane. When the same operation as in Example 9 was performed, the film thickness was 0.27 μm
The relative dielectric constant at 1 MHz of the porous silicon oxide thin film was 1.84.

[0049]

EXAMPLE 11 A sample was prepared by adding 10% of hexamethyldisilazane.
Instead of immersing in a toluene solution for 1 hour, the same operation as in Example 9 was performed, except that a sample was placed in a pressure-resistant container, and then depressurized and then introduced with hexamethyldisilazane vapor at room temperature. However, this film thickness is 0.27 μm
The relative dielectric constant at 1 MHz of the porous silicon oxide thin film was 1.81.

[0050]

Example 12 1.2 g of tetraethoxysilane, polyethylene glycol diacrylate (average molecular weight: 575)
0.68 g was dissolved in a mixed solvent of 2.0 g of N-methylpyrrolidone and 1.0 g of propylene glycol methyl ether acetate, and 0.75 g of water and 0.15 g of 0.1 N nitric acid were added to this solution, and the mixture was stirred at room temperature for 2 hours. Stirred. 0.03 g of 2,2-dimethoxy-2-phenylacetophenone was added to this solution, and 2,000 rpm was placed on a silicon wafer.
m, spin-coated for 10 seconds, and left at 120 ° C. for 1 hour to gel and dry. The composite thin film (thickness: 0.25 μm) thus obtained was irradiated with ultraviolet light for 45 minutes through an exposure mask and immersed in a dilute potassium hydroxide aqueous solution for 3 seconds. Remained on the silicon wafer and could be patterned into the same figure as the exposure mask.

[0051]

Comparative Example 1 In place of polyethylene glycol monomethacrylate and polyethylene glycol dimethacrylate used in Example 2, 1.0 g of polyethylene glycol (average molecular weight: 600) was used, and Example 2 was repeated except that dicumyl peroxide was not added. The same operation as described above was performed to obtain a brown transparent and flexible composite. When a blade of a cutter knife was set on this composite and a weight of 20 grams was applied, the composite was easily torn.

[0052]

Comparative Example 2 The composite obtained in Comparative Example 1 was immersed in water,
Upon standing for 1 hour, a 9% weight loss was observed.

[0053]

Comparative Example 3 The solution used in Comparative Example 1 was spin-coated on a silicon wafer at a speed of 1500 revolutions per minute, and heated at 120 ° C. for 1 hour and at 180 ° C. for 1 hour to obtain a thickness of 0.54 μm.
m was obtained. This sample was placed under a nitrogen atmosphere for 45 minutes.
It was baked at 0 ° C. for 1 hour to burn off the organic polymer and convert it to porous silicon oxide. At this time, the film thickness is 0.24.
μm, and the film thickness was reduced by 56% as compared with that before firing.

[0054]

Comparative Example 4 The solution used in Comparative Example 1 was spin-coated on a silicon wafer with a titanium nitride thin film at a speed of 1500 revolutions per minute, and heated at 120 ° C. for 1 hour and at 180 ° C. for 1 hour. It was baked at 450 ° C. for 1 hour in a nitrogen atmosphere to burn off the organic polymer and convert it to porous silicon oxide.
The film thickness was 0.22 μm. This sample was immersed in a 10% toluene solution of hexamethyldisilazane for 1 hour, and then dried at 120 ° C. under vacuum to modify the pore surface with a trimethylsilyl group to make it hydrophobic. Aluminum was deposited on the top of this thin film through a mask and had a diameter of 1.7.
mm electrode was produced. The relative dielectric constant of the porous silicon oxide thin film at 1 MHz measured using this sample was 2.99, which was 0.82 higher than that of Example 9.

[0055]

Comparative Example 5 5.2 g of tetraethoxysilane and polyvinylpyrrolidone having no polymerizable functional group (average molecular weight: 40
000) was dissolved in a mixed solvent of 3.0 g of ethanol and 3.5 g of dimethylformamide, and 3.5 g of water and 0.65 g of 0.1 N nitric acid were added to the solution.
Stirred for hours. When this solution was cast on a polytetrafluoroethylene watch glass and left at 120 ° C. for 1 hour, the solution gelled. Further, the mixture was left at 180 ° C. for 1 hour to obtain a glassy yellow transparent composite. This was heated and fired in air at 600 ° C. for 1 hour to burn off the organic polymer and convert it to porous silicon oxide. The specific surface area of this porous silicon oxide is 616.6 m.
² / g, and about as compared with the case of Example 6 258m ² /
g less result.

[0056]

Comparative Example 6 1.2 g of tetraethoxysilane, polyethylene glycol having no polymerizable functional group (average molecular weight 2
Ten thousand) 0.68 g, N-methylpyrrolidone 2.0 g, propylene glycol methyl ether acetate 1.0 g
And mixed with 0.75 g of water and 0.15 g of water.
0.15 g of N nitric acid was added, and the mixture was stirred at room temperature for 2 hours. This solution was spin-coated on a silicon wafer at 2000 rpm for 10 seconds, and then left at 120 ° C. for 1 hour to gel.
Let dry. When this was immersed in a dilute aqueous potassium hydroxide solution for 3 seconds, all the films were dissolved and peeled off.

[0057]

According to the present invention, a composite of a silicon oxide and an organic polymer having excellent mechanical strength and solvent resistance can be provided. Since the porous silicon oxide obtained from the composite has a larger surface area and porosity than conventional ones, it can be used as a catalyst carrier, an insulating film for an LSI multilayer wiring having a low dielectric constant, It is very useful in industry.

Claims (5)

[Claims] 1. An alkoxysilane and an organic polymer having at least one polymerizable functional group in a molecule are mixed, and a hydrolysis / dehydration condensation reaction of the alkoxysilane and a functional group contained in the organic polymer are performed. A method for producing an organic-inorganic composite, comprising performing the used polymerization reaction. 2. The organic polymer according to claim 1, wherein the organic polymer having a polymerizable functional group is a polymer mainly composed of an aliphatic polyether, an aliphatic polyester, an aliphatic polycarbonate or an aliphatic polyanhydride. -A method for producing an inorganic composite. 3. An organic-inorganic composite obtained by the method for producing an organic-inorganic composite according to claim 1. 4. A method for producing a porous silicon oxide, comprising removing an organic polymer from the organic-inorganic composite according to claim 3. 5. A porous silicon oxide obtained by the production method according to claim 4.