JP2012224509A - Method for producing porous body of metal oxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method which stably produces a porous body of metal oxide which has a uniform pore size, large specific surface area and pore volume, in particular, a porous body of metal oxide which has crystallinity, the method freely controlling the pore size.SOLUTION: The method for producing a porous body of metal oxide includes a process (a) in which organic polymer particles, metal oxide nano-particles, which are smaller in average particle size than the organic polymer particles, and an aqueous medium are mixed together to prepare a liquid mixture; a process (b) in which the liquid mixture is dried to gain an organic-inorganic composite; and a process (c) in which the organic polymer particles are removed from the organic-inorganic composite to gain the porous body of the metal oxide whose pore size is larger than the size of the crystallite of the metal oxide on the pore wall and which has a particular specific surface area and pore volume.

Description

  The present invention relates to a method for producing a metal oxide porous body.

  Conventionally, a porous material (mesoporous material) having a mesopore with a pore diameter of 2 to 50 nm using a property that a certain surfactant or the like forms a micelle aggregate in a solution in a self-organized manner is used as a template. It has been synthesized from system materials. In 1992, a porous silica material having a mesopore with a diameter of 2 nm or more was developed by Mobil Corporation using a surfactant as a template (Non-patent Document 1). Non-Patent Document 1 discloses MCM-41 type and pores in which cylindrical pores having a diameter of 2 to 8 nm have formed a two-dimensional hexagonal structure by reacting a silica component with cetyltrimethylammonium bromide (CTAB) as a template. Describes a method of synthesizing two types of mesoporous silica of the MCM-48 type in which are three-dimensionally linked.

  Furthermore, by a reaction using a triblock copolymer Pluronic P123 (EOmPOnEOm, m = 17, n = 56, BASF) composed of hydrophilic ethylene oxide (EO) and hydrophobic propylene oxide (PO) as a surfactant, as a template, A method for producing a two-dimensional hexagonal mesoporous silica (SBA-15) having a pore diameter of 10 nm or more is shown. (Non-patent document 2).

  As a method for obtaining a non-silica-based material, particularly a crystalline metal oxide porous body such as titanium dioxide, a three-dimensional hexagonal structure titanium dioxide thin film in which a surfactant Pluronic P123 is present in mesopores is formed and fired Thus, a method for producing a titanium dioxide thin film having both anatase-type crystallites and nano-sized columnar structures is shown. (Non Patent Literature 3)

Furthermore, a cationic surfactant and titanium oxide sulfate are mixed in water, the crystalline titanium dioxide is precipitated, and then the cationic surfactant is removed. A method for producing crystalline mesoporous titanium dioxide containing titanic acid composed of the above crystal structure is disclosed (Patent Documents 1 and 2)
As described above, mesoporous materials that are formed using a micelle structure formed by a surfactant in a self-organized manner as a template have been widely studied. However, surfactants that have been used to date have the property of dynamically changing from a lamellar phase to a two-dimensional hexagonal phase and then to a cubic phase depending on conditions such as dilution concentration in water, pH and temperature. Therefore, there has been a problem that it is difficult to stably produce a mesoporous material having a cubic phase structure having a uniform average pore diameter. When the surfactant Pluronic P123 is used, it is shown that a cubic mesoporous silica or titanium dioxide film having mesopores of about 10 nm is formed only when the concentration in water is 29-32% ( Non-patent document 4).

In addition, a porous crystalline metal oxide such as titanium dioxide is heated in order to transfer an amorphous material into a crystalline structure. Since the wall film is very thin, there is a problem that the amorphous mesoporous shape cannot be maintained. That is, when synthesis is performed at low temperature using a metal alkoxide that is usually used for the preparation of mesoporous materials, the pore walls become amorphous, and a high temperature firing process is required to give a crystalline structure. However, when the baking treatment is performed at a high temperature, the mesoporous shape may be destroyed in the process, so that it is difficult to form a metal oxide porous body having a crystal structure. Alternatively, when it is intended to produce mesoporous titanium dioxide having a direct crystal structure using a technique such as crystal growth, it is difficult to control the crystal size in the nano order, and the structure has a three-dimensionally regularly aligned structure. There are problems such as the fact that it is very difficult to obtain a material and that only the material with low crystallinity can be obtained, and that the characteristics inherent to the crystalline metal oxide cannot be utilized.

C. T.A. Kresge and 4 others, Nature, 359, p. 710-712 (1992) D. Zhao and 6 others, Science, 279, 548 (1998) K. Kuroda et al., 4 members, Journal of the American Chemical Society, 128. p. 4544-4545 (2006) BF Chmelka. 6 others, Chemistry of materials. 14 p. 3284-3294 (2002)

JP2006-0698877 JP 2009-256137 A

  Porous (mesoporous) materials are expected to greatly increase the properties of the materials by increasing the surface area.

  The object of the present invention is to stabilize a metal oxide porous body having a uniform pore diameter, a large specific surface area and a large pore volume, in particular, a metal oxide porous body having crystallinity, and to freely control the pore diameter. It is an object of the present invention to provide a manufacturing method that can be controlled.

That is, the present invention includes the following inventions.
[1] A method for producing a metal oxide porous body comprising the following steps (a), (b) and (c).
Step (a): A mixed liquid containing organic polymer particles dispersible in an aqueous medium, metal oxide nanoparticles, and an aqueous medium is prepared.
(Here, 50% volume average particle diameter measured by dynamic light scattering particle size distribution system of metal oxide nanoparticles is κ, and 50% volume average particle diameter measured by dynamic light scattering particle size distribution system of organic polymer particles. Where γ is γ <γ.)
Step (b): The mixed liquid obtained in the step (a) is dried to obtain an organic-inorganic composite. Step (c): The organic polymer particles are removed from the organic-inorganic composite to obtain a metal oxide porous body that satisfies the following requirements (i), (ii), and (iii).
Requirement (i): α> β
(Α is the average pore diameter determined from BJH analysis by nitrogen adsorption method, and β is the crystallite size of the metal oxide on the pore wall determined by Debye-Scherrer method of powder X-ray analysis.)
Requirement (ii) The BET specific surface area by nitrogen adsorption method is 50 m ² / g or more.
Requirement (iii) The porosity is 50% by volume or more.

[2] The method for producing a porous metal oxide according to [1], wherein γ is 10 to 300 nm and β <γ.

[3] The method for producing a metal oxide porous body according to [1] or [2], wherein the κ is 1 to 50 nm.

[4] The method for producing a metal oxide porous body according to any one of [1] to [3], wherein α is 10 to 300 nm.

[5] The metal oxide porous body according to any one of [1] to [4], wherein the metal oxide porous body has mesopores, and the pore structure thereof is a cubic phase structure. A method for producing a mass.

[6] Metal oxide nanoparticles are silicon (Si), titanium (Ti), zirconium (Zr), yttrium (Y), barium (Ba), aluminum (Al), tin (Sn), hafnium (Hf), antimony Containing a metal selected from the group consisting of (Sb), zinc (Zn), indium (In), lead (Pb), cobalt (Co), lithium (Li), iron (Fe), and manganese (Mn). The method for producing a metal oxide porous body according to any one of [1] to [5].

[7] Organic polymer particles dispersible in an aqueous medium are polyolefin-based, poly (meth) acrylic ester-based, polystyrene-based, polyurethane-based, polyacrylonitrile-based, polyvinyl chloride-based, polyvinylidene chloride-based, polyvinyl acetate-based The method for producing a porous metal oxide according to any one of [1] to [6], which is a water-insoluble polymer particle selected from polybutadiene.

[8] The organic polymer particles dispersible in an aqueous medium are terminal branched polyolefin copolymer particles having a number average molecular weight of 2.5 × 10 ⁴ or less represented by the following general formula (1): The method for producing a porous metal oxide material according to any one of [1] to [7].

(In the formula, A represents a polyolefin chain. R ¹ and R ² represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them is a hydrogen atom. X ¹ and X ² are the same. Or, differently, it represents a group having a linear or branched polyalkylene glycol group.

[9] In the terminal branched copolymer represented by the general formula (1), X ¹ and X ² are the same or different, and the general formula (2)

(In the formula, E represents an oxygen atom or a sulfur atom. X ³ represents a polyalkylene glycol group or the following general formula (3).

(In the formula, R ³ represents an m + 1 valent hydrocarbon group. G is the same or different and is represented by —OX ⁴ , —NX ⁵ X ⁶ (X ^{4 to} X ⁶ represent a polyalkylene glycol group). M represents the number of bonds between R ³ and G, and represents an integer of 1 to 10). )
Or general formula (4)

(Wherein X ⁷ and X ⁸ are the same or different and represent a polyalkylene glycol group or a group represented by the above general formula (3)). The metal oxidation according to [8] A method for producing a porous material.

[10] The method for producing a metal oxide porous material according to [8] or [9], wherein the terminally branched copolymer is represented by the following general formula (1a) or general formula (1b):

(In the formula, R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them is a hydrogen atom. R ⁶ and R ⁷ represent a hydrogen atom or a methyl group, At least one of them is a hydrogen atom, R ⁸ and R ⁹ represent a hydrogen atom or a methyl group, and at least one of them is a hydrogen atom, l + m represents an integer of 2 to 450, n is 20 Represents an integer of 300 or more.)

(In the formula, R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them is a hydrogen atom. R ⁶ and R ⁷ represent a hydrogen atom or a methyl group, At least one of them is a hydrogen atom, R ⁸ and R ⁹ represent a hydrogen atom or a methyl group, at least one of them is a hydrogen atom, R ¹⁰ and R ¹¹ represent a hydrogen atom or a methyl group, At least one of them is a hydrogen atom, l + m + o represents an integer of 3 to 450, and n represents an integer of 20 to 300.)

[11] The method for producing a metal oxide porous body according to any one of [1] to [7], wherein the organic polymer particles are (meth) acrylic acid ester polymer particles.

[12] The metal oxide porous material according to any one of [1] to [11], wherein the step (b) is a step of drying the mixed solution by a spray dryer method to form a particulate organic-inorganic composite. A method for producing a mass.

[13] The metal according to any one of [1] to [11], wherein the step (b) is a step of forming the film-like organic-inorganic composite by applying the mixed liquid onto a substrate and drying it. A method for producing an oxide porous body.

According to the production method of the present invention, a metal oxide porous body having a uniform pore diameter, a large specific surface area and a large pore volume, particularly a metal oxide porous body having crystallinity, can be stably produced.
Moreover, the pore diameter can be freely controlled.

The schematic diagram which shows that the regularity of the porous structure obtained by the relationship between an average pore diameter ((alpha)) and the crystallite size ((beta)) of a metal oxide changes.

  In the present invention, the average pore diameter (α) is larger than the crystallite size (β) of the metal oxide calculated by the Debye-Scherrer method of powder X-ray analysis. A porous material having a specific surface area and a high porosity can be produced.

  First, the reason why a porous material having a uniform pore diameter, a high specific surface area and a high porosity can be produced by making the average pore diameter (α) larger than the crystallite size (β) of the metal oxide. explain. When forming a crystalline metal oxide porous body such as titanium dioxide, first, after forming a complex with an organic material to be a template in an amorphous state, the template material is baked and removed by heating, and further heated. A method of crystallizing the wall portion of the porous body by performing the treatment is employed. At that time, a porous material having small pores has a problem that the wall film is very thin, so that an amorphous porous structure cannot be maintained. In general, a porous material using a surfactant as a template material has a pore diameter of about 4 nm, but the crystallite size of the metal oxide is 5 nm or more in a sufficiently crystallized state. They are about the same size or larger. Therefore, structural change occurs in the process of transition from amorphous to crystalline state, the pores are crushed and uniform pores in the amorphous state cannot be obtained, so the specific surface area and porosity are very low. . The schematic diagram of FIG. 1 shows that the regularity of the porous structure obtained varies depending on the relationship between the average pore diameter (α) and the crystallite size (β) of the metal oxide. In Non-Patent Document 3, a titanium dioxide porous body having a uniform hexagonal structure is obtained in an amorphous state. However, since the pore diameter is small, the pores are bonded to each other by crystallization to form a columnar structure. The pores have changed. In order to suppress the collapse of the pores, metal oxide nanoparticles smaller than the pore diameter are used in advance. After forming the organic material and the organic-inorganic composite as the template, the template material is baked and removed by heating. Since the transition to the state and the wall structure does not change significantly, the collapse of the pores can be suppressed.

  The average pore diameter (α) of the porous material can be determined by nitrogen adsorption. From the nitrogen adsorption / desorption measurement of particles, the specific surface area can be calculated by BET (Brunauer-Emmett-Teller) method and the total pore volume can be calculated by BJH (Barrett-Joyner-Halenda) method. Furthermore, the porosity can be calculated from the total pore volume. The crystallite diameter of the pore wall can be calculated by the Debye-Scherrer method of powder X-ray analysis.

  The average pore diameter (α) is preferably 10 to 300 nm. The pores preferably have a cubic phase structure.

In order to set the average pore diameter (α) to 10 to 300 nm, organic polymer particles that can be dispersed in an aqueous medium and have a volume of 50% and an average particle diameter of 10 to 300 nm are used as a template. After forming the inorganic composite, the organic polymer particles may be removed.
Organic polymer particles that can be dispersed in an aqueous medium include polyolefin, poly (meth) acrylic acid ester, polystyrene, polyurethane, polyacrylonitrile, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, and polybutadiene. Mention may be made of water-insoluble polymer particles selected from the system.

  In particular, a metal oxide porous body having a cubic phase structure having an average pore diameter (α) of 10-30 nm can be stably produced by using polyolefin-based terminally branched copolymer particles dispersed in an aqueous medium. I can do it.

  In addition, a metal oxide porous body having a cubic phase structure having an average pore diameter (α) of more than 30 nm and not more than 300 nm is stable by using, for example, poly (meth) acrylate polymer particles dispersed in an aqueous medium. Can be manufactured.

  First, the terminal branched copolymer particles will be described.

[Polyolefin end-branched copolymer]
The polyolefin terminal branched copolymer constituting the polymer particles used in the present invention has a structure represented by the following general formula (1).

(In the formula, A represents a polyolefin chain. R ¹ and R ² are a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them is a hydrogen atom, and X ¹ and X ² are the same. Or, differently, it represents a group having a linear or branched polyalkylene glycol group.)

The number average molecular weight of the terminal branched copolymer represented by the general formula (1) is 2.5 × 10 ⁴ or less, preferably 5.5 × 10 ^{2 to} 1.5 × 10 ⁴ , more preferably 8 × 10. ^{2 to} 4.0 × 10 ³ . The number average molecular weight is the number average molecular weight of the polyolefin chain represented by A, the number average molecular weight of the group having a polyalkylene glycol group represented by X ¹ and X ² , and R ¹ , R ² and C ₂ H min. It is expressed as the sum of molecular weights.

  When the number average molecular weight of the polyolefin end-branched copolymer is in the above range, the stability of the particles in the dispersion when the polyolefin end-branched copolymer is used as a dispersoid, water and / or affinity with water This is preferable because the dispersibility of the organic solvent in the organic solvent tends to be good and the preparation of the dispersion becomes easy.

  The polyolefin chain which is A in the general formula (1) is obtained by polymerizing an olefin having 2 to 20 carbon atoms. Examples of the olefin having 2 to 20 carbon atoms include α-olefins such as ethylene, propylene, 1-butene and 1-hexene. In the present invention, it may be a homopolymer or copolymer of these olefins, and may be copolymerized with other polymerizable unsaturated compounds as long as the properties are not impaired. Among these olefins, ethylene, propylene, and 1-butene are particularly preferable.

  In general formula (1), the number average molecular weight measured by GPC of the polyolefin chain represented by A is 400 to 8000, preferably 500 to 4000, and more preferably 500 to 2000. Here, the number average molecular weight is a value in terms of polystyrene.

  When the number average molecular weight of the polyolefin chain represented by A is in the above range, the polyolefin portion has high crystallinity, the dispersion tends to be stable, and the melt viscosity is low and the preparation of the dispersion is easy. This is preferable.

The ratio of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by GPC of the polyolefin chain represented by A in the general formula (1), that is, the molecular weight distribution (Mw / Mn) is not particularly limited. However, it is usually 1.0 to several tens, more preferably 4.0 or less, and still more preferably 3.0 or less.
When the molecular weight distribution (Mw / Mn) of the group represented by A in the general formula (1) is in the above range, it is preferable in terms of the shape of the particles in the dispersion and the uniformity of the particle diameter.

  The number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) of the group represented by A by GPC can be measured under the following conditions using, for example, GPC-150 manufactured by Millipore.

Separation column: TSK GNH HT (column size: diameter 7.5 mm, length: 300 mm)
Column temperature: 140 ° C
Mobile phase: Orthodichlorobenzene (Wako Pure Chemical Industries, Ltd.)
Antioxidant: Butylhydroxytoluene (manufactured by Takeda Pharmaceutical Company Limited) 0.025% by mass
Movement speed: 1.0 ml / min Sample concentration: 0.1% by mass
Sample injection volume: 500 microliters Detector: differential refractometer.

  The molecular weight of the polyolefin chain represented by A can be measured by measuring the molecular weight of a polyolefin having an unsaturated group at one terminal, which will be described later, and subtracting the molecular weight corresponding to the terminal.

R ¹ and R ² are a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, which is a substituent bonded to a double bond of the polyolefin constituting A, and preferably a hydrogen atom or a carbon group having 1 to 18 carbon atoms. It is an alkyl group. As the alkyl group, a methyl group, an ethyl group, and a propyl group are preferable.

In the general formula (1), X ¹ and X ² are the same or different and each represents a linear or branched group having a polyalkylene glycol group having a number average molecular weight of 50 to 10,000. The branching mode of the branched alkylene glycol group includes a branching via a polyvalent hydrocarbon group or a nitrogen atom. For example, branching by a hydrocarbon group bonded to two or more nitrogen atoms, oxygen atoms or sulfur atoms in addition to the main skeleton, branching by a nitrogen atom bonded to two alkylene groups in addition to the main skeleton, and the like can be given.

  It is preferable that the number average molecular weight of the group having a polyalkylene glycol group is in the above range because the dispersibility of the dispersion tends to be good and the melt viscosity is low and the preparation of the dispersion is easy.

Since X ¹ and X ^{2 in} the general formula (1) have the above-described structure, a polyolefin end-branched copolymer having a 50% volume average particle diameter of 10 nm to 30 nm without using a surfactant is used. Polymer particles made of a polymer can be obtained stably.

In the general formula (1), preferred examples of X ¹ and X ² are the same or different from each other, and the general formula (2),

(In the formula, E represents an oxygen atom or a sulfur atom, X ³ represents a polyalkylene glycol group, or the following general formula (3)

(Wherein R ³ represents an m + 1 valent hydrocarbon group, G is the same or different, and is represented by —OX ⁴ , —NX ⁵ X ⁶ (X ^{4 to} X ⁶ represent a polyalkylene glycol group). M represents the number of bonds between R ³ and G, and represents an integer of 1 to 10.). )
Or general formula (4)

(Wherein X ⁷ and X ⁸ are the same or different and represent a polyalkylene glycol group or a group represented by the above general formula (3)).

In the general formula (3), the group represented by R ³ is an m + 1 valent hydrocarbon group having 1 to 20 carbon atoms. m is 1-10, 1-6 are preferable and 1-2 are especially preferable.

As a preferred example of the general formula (1), there is a polyolefin terminal branched copolymer in which either X ¹ or X ² is a group represented by the general formula (4) in the general formula (1). Can be mentioned. More preferable examples include polyolefin-based terminally branched copolymers in which ^one of X ¹ and X ² is represented by the general formula (4) and the other is a group represented by the general formula (2). It is done.

As another preferable example of the general formula (1), ^one of X ¹ and X ^{2 in} the general formula (1) is a group represented by the general formula (2), and more preferably X ¹ and X ^2. And polyolefin-based terminally branched copolymers in which both are groups represented by the general formula (2).

As a more preferable structure of X ¹ and X ² represented by the general formula (4), the general formula (5)

(Wherein X ⁹ and X ¹⁰ are the same or different and represent a polyalkylene glycol group, and Q ¹ and Q ² are the same or different and each represents a divalent hydrocarbon group). is there.

The divalent hydrocarbon group represented by Q ¹ and Q ² in the general formula (5) is preferably a divalent alkylene group, and more preferably an alkylene group having 2 to 20 carbon atoms. The alkylene group having 2 to 20 carbon atoms may or may not have a substituent, for example, ethylene group, methylethylene group, ethylethylene group, dimethylethylene group, phenylethylene group, chloromethylethylene group, bromo Examples thereof include a methylethylene group, a methoxymethylethylene group, an aryloxymethylethylene group, a propylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, and a cyclohexylene group. A preferable alkylene group is a hydrocarbon-based alkylene group, particularly preferably an ethylene group or a methylethylene group, and still more preferably an ethylene group. Q ¹ and Q ² may be one kind of alkylene group, or two or more kinds of alkylene groups may be mixed.

As a more preferable structure of X ¹ and X ² represented by the general formula (2), the general formula (6)

(Wherein X ¹¹ represents a polyalkylene glycol group).

The polyalkylene glycol group represented by X ^{3 to} X ¹¹ is a group obtained by addition polymerization of alkylene oxide. Examples of the alkylene oxide constituting the polyalkylene glycol group represented by X ^{3 to} X ¹¹ include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, cyclohexene oxide, epichlorohydrin, epibromohydrin, methyl glycidyl ether, allyl A glycidyl ether etc. are mentioned. Of these, propylene oxide, ethylene oxide, butylene oxide, and styrene oxide are preferable. More preferred are propylene oxide and ethylene oxide, and particularly preferred is ethylene oxide. The polyalkylene glycol group represented by X ^{3 to} X ¹¹ may be a group obtained by homopolymerization of these alkylene oxides or a group obtained by copolymerization of two or more kinds. Examples of preferred polyalkylene glycol groups are polyethylene glycol groups, polypropylene glycol groups, or groups obtained by copolymerization of polyethylene oxide and polypropylene oxide, and particularly preferred groups are polyethylene glycol groups.

When X ¹ and X ² in the general formula (1) have the above structure, water and / or an organic solvent having an affinity for water when the polyolefin end-branched copolymer of the present invention is used as a dispersoid. Since dispersibility becomes favorable, it is preferable.

  As the polyolefin-based terminally branched copolymer that can be used in the present invention, a polymer represented by the following general formula (1a) or (1b) is preferably used.

In the formula, R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them is a hydrogen atom. As the alkyl group, an alkyl group having 1 to 9 carbon atoms is preferable, and an alkyl group having 1 to 3 carbon atoms is more preferable.

R ⁶ and R ⁷ represent a hydrogen atom or a methyl group, and at least one of them is a hydrogen atom. R ⁸ and R ⁹ represent a hydrogen atom or a methyl group, and at least one of them is a hydrogen atom.
l + m represents an integer of 2 to 450, preferably 5 to 200.
n represents an integer of 20 or more and 300 or less, preferably 25 or more and 200 or less.

In the formula, R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them is a hydrogen atom. As the alkyl group, an alkyl group having 1 to 9 carbon atoms is preferable, and an alkyl group having 1 to 3 carbon atoms is more preferable.

R ⁶ and R ⁷ represent a hydrogen atom or a methyl group, and at least one of them is a hydrogen atom. R ⁸ and R ⁹ represent a hydrogen atom or a methyl group, and at least one of them is a hydrogen atom. R ¹⁰ and R ¹¹ represent a hydrogen atom or a methyl group, and at least one of them is a hydrogen atom.
l + m + o represents an integer of 3 to 450, preferably 5 to 200.
n represents an integer of 20 to 300, preferably 25 to 200.

  As the polymer represented by the general formula (1b), it is more preferable to use a polymer represented by the following general formula (1c).

  In the formula, l + m + o and n are the same as those in the general formula (1b).

  The number of ethylene units (n) of the polyethylene chain can be calculated by dividing the number average molecular weight (Mn) of the polyolefin group A in the general formula (1) by the molecular weight of the ethylene unit. Further, the total number of ethylene glycol units (l + m or l + m + o) of the polyethylene glycol chain is such that the weight ratio of the polymer raw material to the ethylene oxide used during the polyethylene glycol group addition reaction is the number average molecular weight of the polymer raw material and the polyethylene glycol group (Mn ) And the ratio can be calculated.

N, l + m or l + m + o can also be measured by ¹ H-NMR. For example, in the polyolefin-based terminally branched copolymer (T) used in the examples of the present invention and the dispersion particles containing the same, the terminal methyl group of the polyolefin group A in the general formula (1) (shift value: 0.88 ppm) ) And the integral value of the methylene group of polyolefin group A (shift value: 1.06-1.50 ppm) and the alkylene group of PEG (shift value: 3.33-3.72 ppm) when the integral value of 3 protons is taken. ) Can be calculated from the integral value.

  Specifically, since the molecular weight of the methyl group is 15, the molecular weight of the methylene group is 14, and the molecular weight of the ethylene oxide group is 44, the number average molecular weights of the polyolefin group A and the alkylene group can be calculated from the values of the integrated values. . By dividing the number average molecular weight of the polyolefin group A thus obtained by the molecular weight of the ethylene unit, n is divided by the number average molecular weight of the alkylene group by the molecular weight of the ethylene glycol unit, whereby the total number of ethylene glycol units (l + m Alternatively, l + m + o) can be calculated.

When the polyolefin group A is composed of an ethylene-propylene copolymer, n and l + m or l + m + o can be obtained by using both the propylene content that can be measured by IR, ¹³ C-NMR, and the integral value in ¹ H-NMR. Can be calculated. ^{In 1} H-NMR, a method using an internal standard is also effective.

[Production method of polyolefin end-branched copolymer]
The polyolefin-based terminally branched copolymer can be produced by the following method.
First, in the target polyolefin-based terminally branched copolymer, as a polymer corresponding to the structure of A represented by the general formula (1), the general formula (7)

(Wherein A represents a polyolefin chain, R ¹ and R ² are a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them represents a hydrogen atom.) A polyolefin having a double bond is produced.

This polyolefin can be produced by the following method.
(1) A transition metal compound having a salicylaldoimine ligand as shown in JP-A Nos. 2000-239312, 2001-27331, 2003-73412, etc. is used as a polymerization catalyst. Polymerization method.
(2) A polymerization method using a titanium catalyst comprising a titanium compound and an organoaluminum compound.
(3) A polymerization method using a vanadium catalyst comprising a vanadium compound and an organoaluminum compound.
(4) A polymerization method using a Ziegler-type catalyst comprising a metallocene compound such as zirconocene and an organoaluminum oxy compound (aluminoxane).

Among the above methods (1) to (4), particularly according to the method (1), the polyolefin can be produced with high yield. In the method (1), a polyolefin having a double bond at one end is produced by polymerizing or copolymerizing the above-described polyolefin in the presence of the transition metal compound having the salicylaldoimine ligand. Can do.

  The polymerization of the polyolefin by the method (1) can be carried out by either a liquid phase polymerization method such as solution polymerization or suspension polymerization or a gas phase polymerization method. Detailed conditions and the like are already known and the above-mentioned patent documents can be referred to.

  The molecular weight of the polyolefin obtained by the method (1) can be adjusted by allowing hydrogen to be present in the polymerization system, changing the polymerization temperature, or changing the type of catalyst used.

  Next, the polyolefin is epoxidized, that is, the double bond at the terminal of the polyolefin is oxidized to obtain a polymer containing an epoxy group at the terminal represented by the general formula (8).

(In the formula, A, R ¹ and R ² are as described above.)

Although the epoxidation method is not particularly limited, the following methods can be exemplified.
(1) Oxidation with peracids such as performic acid, peracetic acid, perbenzoic acid (2) Oxidation with titanosilicate and hydrogen peroxide (3) Oxidation with rhenium oxide catalyst such as methyltrioxorhenium and hydrogen peroxide ( 4) Oxidation with a porphyrin complex catalyst such as manganese porphyrin or iron porphyrin and hydrogen peroxide or hypochlorite (5) Salen complex such as manganese Salen and oxidation with hydrogen peroxide or hypochlorite (6) Manganese- Oxidation with a TACN complex such as a triazacyclononane (TACN) complex and hydrogen peroxide (7) Oxidation with hydrogen peroxide in the presence of a group VI transition metal catalyst such as a tungsten compound and a phase transfer catalyst The above (1) to (7) Among these methods, the methods (1) and (7) are particularly preferable in terms of the active surface.

For example, VIKOLOX ^™ (registered trademark, manufactured by Arkema) can be used as a low molecular weight terminal epoxy group-containing polymer having a Mw of about 400 to 600.

By reacting the terminal epoxy group-containing polymer represented by the general formula (8) obtained by the above-mentioned method with various reaction reagents, the polymer terminal α, β-position represented by the general formula (9) A polymer (polymer (I)) into which various substituents Y ¹ and Y ² are introduced can be obtained.

(In the formula, A, R ¹ and R ² are as described above. Y ¹ and Y ² are the same or different and represent a hydroxyl group, an amino group, or the following general formulas (10a) to (10c).)

(In the general formulas (10a) to (10c), E represents an oxygen atom or a sulfur atom, R ³ represents an m + 1 valent hydrocarbon group, T represents the same or different hydroxyl group and amino group, and m represents 1 Represents an integer of 10 to 10.)

For example, by hydrolyzing the terminal epoxy group-containing polymer represented by the general formula (8), a polymer in which both Y ¹ and Y ² are hydroxyl groups in the general formula (9) is obtained, and ammonia is reacted. By doing so, a polymer in which ^one of Y ¹ and Y ² is an amino group and the other is a hydroxyl group is obtained.

Further, by reacting the terminal epoxy group-containing polymer represented by the general formula (8) with the reaction reagent A represented by the general formula (11a), ^one of Y ¹ and Y ² in the general formula (9) A polymer having a group represented by the general formula (10a) and the other hydroxyl group is obtained.

(In the formula, E, R ³ , T and m are as described above.)

Further, the terminal epoxy group-containing polymer and the reaction reagent B represented by the general formulas (11b) and (11c)
To give a polymer in which one of Y ¹ and Y ² in the general formula (9) is a group represented by the general formula (10b) or (10c) and the other is a hydroxyl group.

(Wherein R ³ , T and m are as described above.)

  Examples of the reaction reagent A represented by the general formula (11a) include glycerin, pentaerythritol, butanetriol, dipentaerythritol, polypentaerythritol, dihydroxybenzene, and trihydroxybenzene.

  Examples of the reaction reagent B represented by the general formulas (11b) and (11c) include ethanolamine, diethanolamine, aminophenol, hexamethyleneimine, ethylenediamine, diaminopropane, diaminobutane, diethylenetriamine, N- (aminoethyl) propanediamine, and imino. Bispropylamine, spermidine, spermine, triethylenetetramine, polyethyleneimine and the like can be mentioned.

  Addition reactions of epoxy compounds with alcohols and amines are well known and can be easily performed by ordinary methods.

  The general formula (1) can be produced by addition polymerization of alkylene oxide using the polymer (I) represented by the general formula (9) as a raw material. Examples of the alkylene oxide include propylene oxide, ethylene oxide, butylene oxide, styrene oxide, cyclohexene oxide, epichlorohydrin, epibromohydrin, methyl glycidyl ether, and allyl glycidyl ether. Two or more of these may be used in combination. Of these, propylene oxide, ethylene oxide, butylene oxide, and styrene oxide are preferable. More preferred are propylene oxide and ethylene oxide.

For the catalyst, polymerization conditions, etc., known ring-opening polymerization methods of alkylene oxides can be used. For example, Takayuki Otsu, “Chemistry of Revised Polymer Synthesis”, Kagaku Dojin, January 1971, p. . 172-180 discloses an example in which a polyol is obtained by polymerizing various monomers. Catalysts used for ring-opening polymerization include Lewis acids such as AlCl ₃ , SbCl ₅ , BF ₃ , and FeCl ₃ for cationic polymerization and alkali metal hydroxides for anionic polymerization as disclosed in the above document. Alternatively, alkaline earth metal oxides, carbonates, alkoxides, or alkoxides such as Al, Zn, and Fe can be used for alkoxides, amines, phosphazene catalysts, and coordination anionic polymerization. Here, as the phosphazene catalyst, for example, an anion of a compound disclosed in JP-A-10-77289, specifically, a commercially available tetrakis [tris (dimethylamino) phosphoranylideneamino] phosphonium chloride is alkalinized. The thing made into the alkoxy anion using the metal alkoxide etc. can be utilized.

  When a reaction solvent is used, the polymer (I) can be inert to the alkylene oxide, alicyclic hydrocarbons such as n-hexane and cyclohexane, and aromatic hydrocarbons such as toluene and xylene. And ethers such as dioxane, and halogenated hydrocarbons such as dichlorobenzene.

Except for the phosphazene catalyst, the catalyst is used in an amount of preferably 0.05 to 5 mol, more preferably 0.1 to 3 mol, relative to 1 mol of the starting polymer (I). The amount of phosphazene catalyst, polymerization rate, in terms of economy and the like, preferably 1 × ¹⁰ -4 ~5 × ^{10 -1} moles per mole of the polymer (I), more preferably 5 × 10 ^{- 4} to 1 × 10 ⁻¹ mol.

  The reaction temperature is usually 25 to 180 ° C., preferably 50 to 150 ° C., and the reaction time varies depending on the reaction conditions such as the amount of catalyst used, reaction temperature, reactivity of polyolefins, etc., but is usually several minutes to 50 hours. .

  As described above, the number average molecular weight of the general formula (1) depends on the method of calculating from the number average molecular weight of the polymer (I) represented by the general formula (8) and the weight of the alkylene oxide to be polymerized, or a method using NMR. Can be calculated.

[Polymer particles]
The polymer particles of the present invention comprising such a polyolefin end-branched copolymer have a structure in which the polyolefin chain portion represented by A in the general formula (1) is oriented in the inward direction. This is a rigid particle having a crystalline part.

  The polymer particles of the present invention can be dispersed again in a liquid such as a solvent even after removal of the particles by drying the dispersion because the polyolefin chain portion has crystallinity. The polymer particles of the present invention are rigid particles in which the melting point of the polyolefin chain portion contained in the particles is preferably 80 ° C. or higher, more preferably 90 ° C. or higher.

  When the melting point of the polyolefin chain portion is in the above range, it becomes a rigid particle having good crystallinity, and even when heated at a higher temperature, the particle collapse is suppressed.

For this reason, in the manufacturing process and use scene which are mentioned later, since collapse of particle | grains is suppressed, the characteristic which the polymer particle of this invention has is not lost, and the yield of a product and the quality of a product are stabilized more.
Even when the polymer particles of the present invention are dispersed in a solvent or the like, the particle diameter is constant regardless of the dilution concentration. That is, since it has redispersibility and a uniform dispersed particle size, it is different from micelle particles dispersed in a liquid.

[Polyolefin end-branched copolymer particle dispersion]
The dispersion of the present invention contains the above-mentioned polyolefin-based terminally branched copolymer in a dispersoid, and the dispersoid is dispersed as particles in water and / or an organic solvent having an affinity for water.

In the present invention, the dispersion is a dispersion obtained by dispersing polyolefin terminal branched copolymer particles,
(1) A dispersion containing the polymer particles, which is obtained when producing polyolefin-based terminally branched copolymer particles,
(2) A dispersion obtained by dispersing or dissolving other dispersoids, additives, and the like in the dispersion containing the polymer particles obtained when the polyolefin-based terminally branched copolymer particles are produced,
(3) A dispersion obtained by dispersing polyolefin-based terminally branched copolymer particles in water or an organic solvent having an affinity for water, and dispersing or dissolving other dispersoids or additives,
Any of these are included.

  The content of the polyolefin-based terminally branched copolymer in the dispersion of the present invention is preferably 0.1 to 50% by mass, more preferably 1 to 40% by mass when the total dispersion is 100% by mass. More preferably, it is 1-20 mass%.

  It is preferable that the content ratio of the polyolefin-based terminally branched copolymer is in the above range because the practicality of the dispersion is good, the viscosity can be kept appropriate, and handling becomes easy. The 50% volume average particle diameter of the particles in the dispersion of the present invention is preferably 10 nm or more and 30 nm or less.

  The 50% volume average particle size of the particles can be adjusted by changing the structure of the polyolefin portion and the structure of the terminal branch portion of the polyolefin-based terminal branched copolymer.

  The 50% volume average particle diameter in the present invention means the diameter of a particle when the total volume is 100% when the total volume is 100%, and is a dynamic light scattering particle size distribution measuring device or a microtrack particle size. It can be measured using a distribution measuring device.

The shape can be observed with a transmission electron microscope (TEM) after negative staining with, for example, phosphotungstic acid.
The dispersion in the present invention can be obtained by dispersing the polyolefin-based terminally branched copolymer in water and / or an organic solvent having an affinity for water.

  Dispersion in the present invention can be carried out by a method of physically dispersing a polyolefin-based terminally branched copolymer in water and / or an organic solvent having an affinity for water by mechanical shearing force.

  The dispersion method is not particularly limited, but various dispersion methods can be used. Specifically, the polyolefin-based terminally branched copolymer represented by the general formula (1) and water and / or an organic solvent having an affinity for water are mixed and then melted to obtain a high-pressure homogenizer, Examples thereof include a method of dispersing with a homomixer, an extrusion kneader, an autoclave, a method of spraying and pulverizing at a high pressure, and a method of spraying from pores. In addition, after dissolving the polyolefin-based terminally branched copolymer in a solvent other than water in advance, it is mixed with water and / or an organic solvent having an affinity for water and dispersed with a high-pressure homogenizer, a high-pressure homomixer, or the like. A method is also possible. At this time, the solvent used for dissolving the polyolefin end-branched copolymer is not particularly limited as long as the polyolefin end-branched copolymer dissolves, but has an affinity for toluene, cyclohexane or the above water. An organic solvent etc. are mentioned. When it is not preferable that an organic solvent other than water is mixed in the dispersion, it can be removed by an operation such as distillation.

  More specifically, for example, in an autoclave equipped with a stirrer capable of applying a shearing force, a dispersion is obtained by heating and stirring while applying a shearing force at a temperature of 100 ° C. or higher, preferably 120 to 200 ° C. be able to.

  When the temperature is within the above temperature range, the polyolefin end-branched copolymer is in a molten state, so that it can be easily dispersed, and the polyolefin end-branched copolymer is not easily deteriorated by heating.

  The time required for dispersion varies depending on the dispersion temperature and other dispersion conditions, but is about 1 to 300 minutes.

  The above stirring time is preferable because dispersion can be sufficiently performed and the polyolefin-based terminally branched copolymer is hardly deteriorated. After the reaction, it is preferable to maintain a state in which shearing force is applied until the temperature in the dispersion becomes 100 ° C. or lower, preferably 60 ° C. or lower.

  In the production of the dispersion used in the present invention, addition of a surfactant is not indispensable, but for example, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant and the like may coexist.

  Anionic surfactants include, for example, carboxylates, simple alkyl sulfonates, modified alkyl sulfonates, alkyl allyl sulfonates, alkyl sulfate esters, sulfated oils, sulfate esters, sulfated fatty acid monoglycerides, sulfated alkanol amides. Sulphated ethers, alkyl phosphate esters, alkyl benzene phosphonates, naphthalene sulfonic acid / formalin condensates.

  Examples of cationic surfactants include simple amine salts, modified amine salts, tetraalkyl quaternary ammonium salts, modified trialkyl quaternary ammonium salts, trialkyl benzyl quaternary ammonium salts, and modified trialkyl benzyl quaternary salts. Examples include quaternary ammonium salts, alkyl pyridinium salts, modified alkyl pyridinium salts, alkyl quinolinium salts, alkyl phosphonium salts, and alkyl sulfonium salts.

  Examples of amphoteric surfactants include betaine, sulfobetaine, sulfate betaine and the like.

Nonionic surfactants include, for example, fatty acid monoglycerin ester, fatty acid polyglycol ester, fatty acid sorbitan ester, fatty acid sucrose ester, fatty acid alkanol amide, fatty acid polyethylene glycol glycol condensate, fatty acid amide polyethylene glycol condensate, Examples include fatty acid alcohol / polyethylene / glycol condensate, fatty acid amine / polyethylene / glycol condensate, fatty acid mercaptan / polyethylene / glycol condensate, alkyl / phenol / polyethylene / glycol condensate, and polypropylene / glycol / polyethylene / glycol condensate. .
These surfactants can be used alone or in combination of two or more.

  In the production of the dispersion used in the present invention, a filtration step may be provided in the process for the purpose of removing foreign substances and the like. In such a case, for example, a stainless steel filter (wire diameter 0.035 mm, plain weave) of about 300 mesh may be installed and pressure filtration (air pressure 0.2 MPa) may be performed.

  The dispersion obtained by the above method has a pH of 1 by adding various acids and bases, for example, acids such as hydrochloric acid, sulfuric acid and phosphoric acid, and bases such as potassium hydroxide, sodium hydroxide and calcium hydroxide. No change or aggregation occurs from 13 to 13. In addition, the dispersion does not aggregate or precipitate even in a wide temperature range in which heating and refluxing or freezing and thawing are repeated under normal pressure.

  The water in the above method is not particularly limited, and distilled water, ion exchange water, city water, industrial water, and the like can be used, but it is preferable to use distilled water or ion exchange water.

  In addition, the organic solvent having an affinity for water in the above method is not particularly limited as long as the dispersoid such as polyolefin-based terminal copolymer particles and surfactant can be dispersed. For example, ethylene glycol, tetraethylene glycol Isopropyl alcohol, acetone, acetonitrile, methanol, ethanol, dimethyl sulfoxide, dimethylformamide, dimethylimidazolidinone and the like. When mixing of the organic solvent into the dispersion is not preferred, the organic solvent can be removed by distillation or the like after preparing a dispersion containing the dispersoid.

  In the dispersion in the present invention, when the polyolefin-based terminal branched copolymer is 100 parts by mass, the dispersoid other than the polyolefin-based terminal copolymer particles is 0.001 to 20 parts by mass, preferably 0. 0.01 parts by mass to 10 parts by mass, more preferably 0.1 parts by mass to 5 parts by mass.

It is preferable that the content of the dispersoid be in the above range since the physical properties of the dispersion are good in practical use and the dispersion is less likely to aggregate and precipitate.
A metal oxide porous body having a cubic phase structure having an average pore diameter (α) of more than 30 nm and not more than 300 nm is produced, for example, by using poly (meth) acrylate polymer particles dispersed in an aqueous medium. I can do it. Next, the poly (meth) acrylate polymer particles will be described.

[(Meth) acrylic acid ester polymer particle aqueous dispersion]
The poly (meth) acrylate polymer is a homopolymer or copolymer having a repeating unit derived from an acrylate ester and / or a methacrylic ester.

  An aqueous dispersion of poly (meth) acrylic acid ester polymer particles is generally called an acrylic emulsion and can be obtained by a known emulsion polymerization method. For example, it can be obtained by emulsion polymerization of an unsaturated monomer (such as an unsaturated vinyl monomer) in water containing a polymerization initiator and a surfactant.

  Specific examples of the acrylic ester include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, Examples include decyl acrylate, dodecyl acrylate, octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, and glycidyl acrylate.

  Specific examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate. , Dodecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, glycidyl methacrylate and the like.

The poly (meth) acrylic acid ester polymer of the present invention may be copolymerized with an unsaturated monomer other than acrylic acid ester and methacrylic acid ester.
Unsaturated monomers that can be used in combination include vinyl esters such as vinyl acetate; vinylcyan compounds such as acrylonitrile and methacrylonitrile; halogenated monomers such as vinylidene chloride and vinyl chloride; styrene, α-methylstyrene , Vinyltoluene, 4-t-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene and other aromatic vinyl monomers; ethylene, propylene and other olefins; butadiene, chloroprene and other dienes; vinyl ether, vinyl ketone and vinyl Vinyl monomers such as pyrrolidone; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid and maleic acid; acrylamides such as acrylamide, methacrylamide and N, N′-dimethylacrylamide; 2-hydroxy Ethyl acrylate 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, hydroxyl group-containing monomers such as 2-hydroxypropyl methacrylate and the like, can be used as a mixture thereof alone or two or more.

  A crosslinkable monomer having two or more polymerizable double bonds can also be used. Examples of the crosslinkable monomer having two or more polymerizable double bonds include polyethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, 1,9-nonanediol diacrylate, polypropylene glycol diacrylate, 2,2′-bis (4-acryloxypropyloxyphenyl) propane, 2,2 ′ -Diacrylate compounds such as bis (4-acryloxydiethoxyphenyl) propane, triacrylate compounds such as trimethylolpropane triacrylate, trimethylolethane triacrylate, tetramethylolmethane triacrylate , Tetraacrylate compounds such as ditrimethylol tetraacrylate, tetramethylol methane tetraacrylate, pentaerythritol tetraacrylate, hexaacrylate compounds such as dipentaerythritol hexaacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol Dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, polybutylene glycol Dimethacrylate, , 2′-bis (4-methacryloxydiethoxyphenyl) propane and other dimethacrylate compounds, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate and other trimethacrylate compounds, methylenebisacrylamide, divinylbenzene and the like. Can be used alone or in admixture of two or more.

  In addition to the polymerization initiator and surfactant used in emulsion polymerization, a chain transfer agent, further a neutralizing agent, and the like may be used according to a conventional method. In particular, ammonia and inorganic alkali hydroxides such as sodium hydroxide and potassium hydroxide are preferred as the neutralizing agent.

From the viewpoint of dispersion stability in water, the poly (meth) acrylate polymer particles preferably have a volume 50% average particle diameter (γ) of more than 30 nm and not more than 300 nm, more preferably 40 to 250 nm. In particular, the thickness is preferably 50 to 200 nm.
Moreover, as a poly (meth) acrylic-ester type polymer particle, any of a single phase structure and a multiphase structure (core shell type) can be used.

The term “acrylic emulsion” is intended to include a solid / liquid dispersion called dispersion, latex, or suspension.
An acrylic emulsion is manufactured as follows, for example.

[Example of production method of acrylic emulsion]
In a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser and a stirrer, 100 parts of ion-exchanged water is added, and 0.2 part of a polymerization initiator is added while stirring at a temperature of 70 ° C. in a nitrogen atmosphere. To this, a separately prepared monomer solution is dropped and subjected to a polymerization reaction to prepare a primary substance. Thereafter, at a temperature of 70 ° C., 2 parts of a 10% aqueous solution of a polymerization initiator is added to the primary substance and stirred, and a separately prepared reaction solution is added and stirred to cause a polymerization reaction to obtain a polymerization reaction product. . The polymerization reaction product may be used as it is, or it may be neutralized with a neutralizing agent and adjusted to have a pH of 8 to 8.5. Thereafter, it is filtered through a filter to remove coarse particles, and an acrylic emulsion having resin particles as a dispersoid is obtained.

As the polymerization initiator, those used for normal radical polymerization are used, for example, potassium persulfate, ammonium persulfate, hydrogen peroxide, azobisisobutyronitrile, benzoyl peroxide, dibutyl peroxide, Examples include peracetic acid, cumene hydroperoxide, t-butyl hydroxy peroxide, paramentane hydroxy peroxide, and the like. In particular, as described above, when the polymerization reaction is performed in water, a water-soluble polymerization initiator is preferable.
Moreover, as an emulsifier used by a polymerization reaction, what is generally used as an anionic surfactant, a nonionic surfactant, or an amphoteric surfactant other than sodium lauryl sulfate is mentioned, for example.

Examples of the chain transfer agent used in the polymerization reaction include t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, xanthogens such as dimethylxanthogen disulfide, diisobutylxanthogen disulfide, dipentene, indene, 1,4- Examples include cyclohexadiene, dihydrofuran, and xanthene.
The acrylic emulsion can be used in combination with an organic solvent in addition to water. As such an organic solvent, those having compatibility with water are preferable. For example, alkyl alcohols having 1 to 4 carbon atoms such as ethanol, methanol, butanol, propanol, isopropanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl, and the like. Ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono -N-butyl ether, ethylene glycol mono-t-butyl ether, polyethylene Glycol mono-t-butyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-iso- Glycol ethers such as propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether, 2-pyrrolidone, formamide, acetamide, dimethyl Examples include sulfoxide, sorbit, sorbitan, acetin, diacetin, triacetin, and sulfolane. It can be used alone or in combination of two or more of al.

  Hereinafter, a method for producing a metal oxide porous body using the water-insoluble organic polymer particles described above will be described.

<The manufacturing method of a metal oxide porous body>
The metal oxide porous body of the present invention is produced by forming a water-insoluble organic polymer particle and an organic-inorganic composite of a metal oxide and then removing the water-insoluble organic polymer particle as a template.

Specifically, the following steps are included.
Step (a): A mixed solution containing the above-mentioned water-insoluble organic polymer particles, metal oxide nanoparticles and an aqueous medium is prepared.
Step (b): The mixed liquid obtained in the step (a) is dried to obtain an organic-inorganic composite.
Step (c): The water-insoluble organic polymer particles are removed from the organic-inorganic composite to prepare a metal oxide porous body.

Hereinafter, each process is demonstrated in order.
[Step (a)]
In step (a), for example, an aqueous dispersion of metal oxide nanoparticles can be prepared and mixed or reacted with the aqueous dispersion of water-insoluble organic polymer particles described above to prepare a liquid. Specifically, the metal oxide nanoparticles selected in the present invention are silicon dioxide (SiO ₂ ), titanium dioxide (TiO ₂ ), zirconium dioxide (ZrO ₂ ), yttria stabilized zirconium (YSZ), aluminum oxide (Al ₂ O ₃ ), barium titanate (BaTiO ₃ ), antimony oxide (Sb ₂ O ₅ ), tin oxide (SnO), zinc oxide (ZnO), lithium iron phosphate (LiFePO ₄ ), lithium manganese phosphate (LiMnPO ₄₎ ) And metal oxide nanoparticles containing one or more components.

  More specifically, the metal oxide nanoparticles containing two or more components are a structure in which one or more inorganic ultrafine particles are coated with one or more other inorganic substances (core-shell structure) and a crystal structure with two or more components. Such as to be formed.

  The volume 50% average particle diameter (κ) of the metal oxide nanoparticles is smaller than the volume 50% average particle diameter (γ) of the organic polymer particles. κ / γ is preferably 0.003 to 0.99, particularly preferably 0.005 to 0.9.

  By using such metal nanoparticles and organic polymer particles, a metal oxide porous body satisfying requirements (i), (ii) and (iii) described later can be stably produced.

  The 50% volume average particle diameter (κ) of the metal oxide nanoparticles is preferably 1 to 50 nm, more preferably 1 to 20 nm, and still more preferably 1 to 10 nm. Within this range, the properties as nanoparticles are maintained, and the regularity of the pores of the resulting porous body is good, which is preferable.

  In addition, the method for producing metal oxide nanoparticles can be roughly divided into a pulverization method and a synthesis method. Further, as synthesis methods, there are vapor phase methods such as evaporation condensation method and gas phase reaction method, liquid phase methods such as colloid method, homogeneous precipitation method, hydrothermal synthesis method and microemulsion method.

  The method for producing the metal oxide nanoparticles used in the present invention is not particularly limited, but those produced by a synthesis method are preferable from the viewpoints of particle size, composition uniformity, impurities, and the like.

  Each metal oxide nanoparticle is preferably dispersed in water or the like in a colloidal or slurry form. In order to keep the dispersion stable, a silane such as γ-glycidoxypropyltrimethoxysilane or methacryloyloxypropyltrimethoxysilane is used. The dispersion may be stabilized by adding a coupling agent, an organic acid such as a carboxylic acid, a polymer such as polyvinyl pyrrolidone or polyvinyl alcohol, or chemically bonding (surface modification) them to the surface of the fine particles.

  Examples of the aqueous medium in which the metal oxide nanoparticles are dispersed include water and / or a solvent that dissolves part or all of water in an arbitrary ratio.

  The water is not particularly limited, and distilled water, ion exchange water, city water, industrial water, and the like can be used, but it is preferable to use distilled water or ion exchange water.

  The solvent for dissolving a part or all of water in an arbitrary ratio is not particularly limited as long as it is an organic solvent having an affinity for water and can disperse the water-insoluble organic polymer. Ethanol, propyl alcohol, isopropyl alcohol, acetone, acetonitrile, dimethyl sulfoxide, dimethylformamide, dimethylimidazolidinone, ethylene glycol, tetraethylene glycol, dimethylacetamide, N-methyl-2-pyrrolidone, tetrahydrofuran, dioxane, methyl ethyl ketone, cyclohexanone, cyclo Examples include pentanone, 2-methoxyethanol (methyl cellosolve), 2-ethoxyethanol (ethyl cellosolve), and ethyl acetate. Among these, methanol, ethanol, propyl alcohol, isopropyl alcohol, acetonitrile, dimethyl sulfoxide, dimethylformamide, acetone, tetrahydrofuran, and dioxane are preferable because of their high affinity with water.

The aqueous dispersion of metal oxide nanoparticles can be mixed with the water-insoluble organic polymer particles and used in the form of a mixed composition.
The 50% average particle diameter (κ) of the metal oxide nanoparticles and the 50% average particle diameter (γ) of the organic polymer particles can be directly observed by a transmission electron microscope (TEM). The dispersed particle size in water can be measured with a dynamic light scattering nanotrack particle size analyzer “Microtrack UPA-EX150 (manufactured by Nikkiso Co., Ltd.)”.
The amount of the organic polymer particles used is not particularly limited. For example, the organic polymer particles / metal oxide nanoparticles (weight ratio) is 10/90 to 90/10, preferably 20/80 to 80/20. be able to.

[Step (b)]
In the step (b), the liquid mixture obtained in the step (a) is dried to obtain an organic-inorganic composite. The organic-inorganic composite may be in the form of particles or a film.

As a method for producing composite particles, the reaction solution of the present invention, a mixed composition is heated and dried at a predetermined temperature to remove water or a solvent, and then the obtained solid is molded by a treatment such as pulverization or classification, or After drying by removing water or solvent at a low temperature as in the freeze-drying method, it is further dried by heating at a predetermined temperature, and the resulting solid is formed by pulverization or classification, and further by a spray dryer, 10 μm There is a method of obtaining powder by spraying the following composite fine particles with a spray dryer (spray dryer) and volatilizing the solvent.
According to the intended use, the type of substrate and the shape, etc., the film-like composite can be produced by dip coating, spin coating, spray coating, flow coating, blade coating, bar coating, die coating, or other appropriate methods. The method can be used. As the substrate, a porous support can be used in addition to a molded product such as metal, glass, ceramics, and polymer, a sheet, a film, and the like.

As a method for producing a porous support and a membrane-like composite, a method of immersing the porous support in a mixed composition, holding the porous support at a predetermined temperature, and drying can be exemplified.
Examples of the porous support include porous materials such as ceramics such as silica, alumina, zirconia, and titania, metals such as stainless steel and aluminum, paper, and resins.

[Step (c)]
In the step (c), the water-insoluble organic polymer is removed from the organic-inorganic composite obtained in the step (b) to prepare a metal oxide porous body.

As a method of removing the water-insoluble organic polymer particles, a method of decomposing and removing by firing, a method of decomposing and removing by irradiating with VUV light (vacuum ultraviolet light), far infrared rays, microwaves, plasma,
Examples of the method include extraction and removal using a solvent and water. When decomposing and removing by firing, a preferable temperature is 300 ° C to 2000 ° C, more preferably 400 ° C to 1000 ° C, and still more preferably 500 ° C to 800 ° C. If the firing temperature is too low, the water-insoluble organic polymer particles are not removed, while if too high, the crystallite size increases and becomes larger than the pore diameter, so that the regularity of the structure is lost or the melting point of the metal oxide In some cases, the pores collapse. Firing may be performed at a constant temperature, or may be gradually raised from room temperature. The firing time can be changed according to the temperature, but it is preferably performed in the range of 1 hour to 24 hours. Firing may be performed in air or in an inert gas such as nitrogen or argon. Moreover, you may carry out under reduced pressure or in a vacuum. In the case of irradiating and removing by VUV light, a VUV lamp, an excimer laser, or an excimer lamp can be used. May be used in combination with oxidation action of ozone (O ₃₎ generated at the time of irradiating the VUV light in air. As the microwave, any frequency of 2.45 GHz or 28 GHz may be used. The output of the microwave is not particularly limited, and a condition for removing the water-insoluble organic polymer particles is selected.

  When extraction is performed using a solvent or water, for example, ethylene glycol, tetraethylene glycol, isopropyl alcohol, acetone, acetonitrile, methanol, ethanol, cyclohexane, dimethyl sulfoxide, dimethylformamide, dimethylimidazolidinone, xylene, toluene , Chloroform, dichloromethane and the like can be used. The extraction operation may be performed under heating. Further, ultrasonic (US) treatment may be used in combination. In addition, after performing extraction operation, in order to remove the water | moisture content and solvent which remain | survive in a pore, it is preferable to perform heat processing under reduced pressure.

  The metal oxide porous body of the present invention is a mesoporous structure having uniform pores, and preferably has a cubic structure.

  Although the reason why a porous metal oxide having pores forming a cubic phase structure is obtained by using the water-insoluble organic polymer particles in the present invention as a template is not clear, it is presumed as follows: Is done.

  In step (a) of the above-mentioned “metal oxide porous body production method”, when a plurality of water-insoluble organic polymer particles are added to the aqueous dispersion of metal oxide nanoparticles, a plurality of water-insoluble organic polymer particles are obtained. Repel each other by a predetermined surface charge, and are dispersed in a thermodynamically stable state with a predetermined distance, that is, a cubic structure such as Fm3m.

Therefore, the pores of the metal oxide porous particles formed by removing the water-insoluble organic polymer particles dispersed in this way by calcination form a cubic phase.
The metal oxide porous body of the present invention satisfies the following requirements (i), (ii) and (iii).
Requirement (i): α> β
(Α is the average pore diameter determined from BJH analysis by nitrogen adsorption method, and β is the crystallite size of the metal oxide on the pore wall determined by Debye-Scherrer method of powder X-ray analysis.)
α is preferably 20 to 300 nm, more preferably 20 to 250 nm, and particularly preferably 20 to 200 nm.
β only needs to be smaller than α, and is preferably 0.1 to 18 nm. β / α is preferably 0.003 to 0.99, and more preferably 0.005 to 0.9. Β is smaller than γ described above.
Requirement (ii) The BET specific surface area by nitrogen adsorption method is 50 m ² / g or more. Preferably it is 50-300 m < ² > / g, and 50-200 m < ² > / g is especially preferable.
Requirement (iii) The porosity is 50% by volume or more. Preferably it is 50-95 volume%, and 60-90 volume% is especially preferable.

The regularity of the pores of the metal oxide porous body obtained by the steps (a) to (c) can be confirmed by a transmission electron microscope (TEM). When α> β, a regular structure is obtained. On the other hand, when α <β, the structure is irregular. As described above, α> β can be achieved by using metal oxide nanoparticles and organic polymer particles satisfying κ <γ. Further, in the step (c), the crystallite size (β) can be set to α> β by adjusting the firing temperature according to the raw material.

In addition, since the metal oxide porous body of the present invention has a uniform pore size, for example, the weight ratio of the metal oxide nanoparticles as a raw material and the organic polymer particles is changed, or the particle size of the organic polymer particles is changed. Thus, it is possible to control the specific surface area and the porosity to a desired range.
The metal oxide porous body of the present invention thus obtained can be used as, for example, a catalyst, a catalyst carrier, a solid electrolyte or electrode material for a solid oxide fuel cell (SOFC), a piezoelectric material, and an electrode material for a dye-sensitized solar cell. Can be used.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited to these examples.

<Water-insoluble organic polymer particles-1>
<Synthesis of polyolefin end-branched copolymer>
Number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn) were measured by GPC using the method described in the text. Moreover, the peak top temperature obtained by measuring using DSC was employ | adopted for melting | fusing point (Tm). In addition, although melting | fusing point of a polyalkylene glycol part is also confirmed by measurement conditions, here, unless there is particular notice, it refers to melting | fusing point of a polyolefin part. ¹ H-NMR was measured at 120 ° C. after completely dissolving the polymer in deuterated 1,1,2,2-tetrachloroethane serving as a lock solvent and a solvent in a measurement sample tube. . The chemical shift was determined by setting the peak of deuterated 1,1,2,2-tetrachloroethane to 5.92 ppm and determining the chemical shift value of other peaks. As for the particle diameter of the particles in the dispersion, a 50% volume average particle diameter was measured with Microtrac UPA (manufactured by HONEYWELL). The shape of the particles in the dispersion was observed by diluting the sample 200 to 500 times, negatively staining with phosphotungstic acid, and then using a transmission electron microscope (TEM / H-7650 manufactured by Hitachi, Ltd.) under the condition of 100 kV. I did it.

(Synthesis of polyolefin end-branched copolymer (T))
A terminal epoxy group-containing ethylene polymer (E) was synthesized according to the following procedure (for example, see Synthesis Example 2 of JP-A-2006-131870).

A stainless steel autoclave with an internal volume of 2000 ml sufficiently purged with nitrogen was charged with 1000 ml of heptane at room temperature, and the temperature was raised to 150 ° C. Subsequently, 30 kg / cm ² G was pressurized with ethylene in the autoclave to maintain the temperature. A hexane solution (1.00 mmol / ml of aluminum atom equivalent) of MMAO (manufactured by Tosoh Finechem) was injected with 0.5 ml (0.5 mmol), and then a toluene solution (0.0002 mmol / ml) of a compound of the following formula: 0.5 ml (0.0001 mmol) was injected to initiate the polymerization. After carrying out the polymerization at 150 ° C. for 30 minutes in an ethylene gas atmosphere, the polymerization was stopped by press-fitting a small amount of methanol. The obtained polymer solution was added to 3 liters of methanol containing a small amount of hydrochloric acid to precipitate a polymer. After washing with methanol, it was dried under reduced pressure at 80 ° C. for 10 hours to obtain a single-end double bond-containing ethylene polymer (P).

In a 500 ml separable flask, 100 g of the ethylene polymer (P) containing one end double bond (Mn850, vinyl group 108 mmol), 300 g of toluene, 0.85 g (2.6 mmol) of Na ₂ WO ₄ , CH ₃ (nC ₈ H ₁₇ ) ₃ NHSO ₄ (0.60 g, 1.3 mmol) and phosphoric acid (0.11 g, 1.3 mmol) were charged, and the mixture was heated to reflux with stirring for 30 minutes to completely melt the polymer. After the internal temperature was set to 90 ° C., 37 g (326 mmol) of 30% hydrogen peroxide solution was added dropwise over 3 hours, and the mixture was stirred at an internal temperature of 90 to 92 ° C. for 3 hours. Thereafter, 34.4 g (54.4 mmol) of a 25% aqueous sodium thiosulfate solution was added while maintaining the temperature at 90 ° C., and the mixture was stirred for 30 minutes. The peroxide in the reaction system was completely decomposed with the peroxide test paper. It was confirmed. Subsequently, 200 g of dioxane was added at an internal temperature of 90 ° C. to crystallize the product, and the solid was collected by filtration and washed with dioxane. The obtained solid was stirred in a 50% aqueous methanol solution at room temperature, and the solid was collected by filtration and washed with methanol. Further, the solid was stirred in 400 g of methanol, collected by filtration and washed with methanol. By drying under reduced pressure of room temperature and 1-2 hPa, 96.3 g of white solid of terminal epoxy group-containing ethylene polymer (E) was obtained (yield 99%, polyolefin conversion rate 100%).

The obtained terminal epoxy group-containing ethylene polymer (E) was Mw = 2058, Mn = 1118, Mw / Mn = 1.84 (GPC). (Terminal epoxy group content: 90 mol%)
¹ H-NMR: δ (C2D2Cl4) 0.88 (t, 3H, J = 6.92 Hz), 1.18-1.66 (m), 2.38 (dd, 1H, J = 2.64, 5.28 Hz), 2.66 (dd, 1H, J = 4.29, 5.28 Hz), 2.80-2.87 (m, 1H)
Melting point (Tm) 121 ℃
Mw = 2058, Mn = 1118, Mw / Mn = 1.84 (GPC)

A 1000 mL flask was charged with 84 parts by weight of a terminal epoxy group-containing ethylene polymer (E), 39.4 parts by weight of diethanolamine, and 150 parts by weight of toluene, and stirred at 150 ° C. for 4 hours. Thereafter, acetone was added while cooling to precipitate the reaction product, and the solid was collected by filtration. The obtained solid was stirred and washed once with an aqueous acetone solution and further three times with acetone, and then the solid was collected by filtration. Thereafter, the polymer (I) (Mn = 1223, A: group formed by polymerization of ethylene (Mn = 1075) in the general formula (9) (Mn = 1075), R ¹ = R ² = by drying under reduced pressure at room temperature. A hydrogen atom, ^one of Y ¹ and Y ² was a hydroxyl group, and the other was a bis (2-hydroxyethyl) amino group).
¹ H-NMR: δ (C2D2Cl4) 0.88 (t, 3H, J = 6.6 Hz), 0.95-1.92 (m), 2.38-2.85 (m, 6H), 3.54-3.71 (m, 5H)
Melting point (Tm) 121 ℃

A 500 mL flask equipped with a nitrogen introduction tube, a thermometer, a cooling tube, and a stirrer is charged with 20.0 parts by weight of polymer (I) and 100 parts by weight of toluene and heated in an oil bath at 125 ° C. while stirring to obtain a solid. Was completely dissolved. After cooling to 90 ° C., 0.323 parts by weight of 85% KOH previously dissolved in 5.0 parts by weight of water was added to the flask and mixed for 2 hours under reflux conditions. Thereafter, water and toluene were distilled off while gradually raising the temperature in the flask to 120 ° C. Further, while supplying a slight amount of nitrogen to the flask, the pressure in the flask was reduced, and the internal temperature was raised to 150 ° C. and maintained for 4 hours to further distill off water and toluene in the flask. After cooling to room temperature, the solidified solid in the flask was crushed and taken out.

A stainless steel 1.5 L pressure reactor equipped with a heating device, a stirring device, a thermometer, a pressure gauge, and a safety valve was charged with 18.0 parts by weight of the obtained solid and 200 parts by weight of dehydrated toluene. After substituting with nitrogen, the temperature was raised to 130 ° C. with stirring. After 30 minutes, 9.0 parts by weight of ethylene oxide was added, and the mixture was further maintained at 130 ° C. for 5 hours, and then cooled to room temperature to obtain a reaction product. Solvent is removed by drying from the obtained reaction product, and polyolefin-based terminally branched copolymerization (T) (Mn = 1835, in formula (1), A: group formed by polymerization of ethylene (Mn = 1975), R ¹ = R ² = hydrogen atom, ^one of X ¹ and X ² is a group represented by the general formula (6) (X ¹¹ = polyethylene glycol group), and the other is a group represented by the general formula (5) (Q ¹ = Q ² = ethylene group, X ⁹ = X ¹⁰ = polyethylene glycol group)).
¹ H-NMR: δ (C2D2Cl4) 0.88 (3H, t, J = 6.8 Hz), 1.06-1.50 (m), 2.80-3.20 (m), 3.33-3.72 (m)
Melting point (Tm) -16 ° C (polyethylene glycol), 116 ° C

<Preparation Example of Polyolefin-Based Branched Copolymer Aqueous Dispersion>
(Preparation of 10% by weight polyolefin end-branched copolymer (T) aqueous dispersion)
10 parts by weight of the polyolefin end branched copolymer (T) obtained in the above synthesis example and 40 parts by weight of distilled water were charged into a 100 ml autoclave, heated and stirred at 140 ° C. and 800 rpm for 30 minutes, The mixture was cooled to room temperature while maintaining stirring. The obtained dispersion had a volume 50% average particle size of 18 nm. (Volume 10% average particle diameter 14 nm, volume 90% average particle diameter 22 nm) The particle diameter measured from the transmission electron microscope observation result of the obtained dispersion was 15 to 30 nm. Further, 75 parts by weight of distilled water is added to 75 parts by weight of this (T) aqueous dispersion (solid content: 20% by weight) to obtain a 10% by weight polyolefin-based terminally branched copolymer (T) aqueous dispersion. It was.

<Water-insoluble organic polymer particles-2>
As an aqueous dispersion (acrylic emulsion) of a polymethacrylic acid ester copolymer, PAN-6 manufactured by Mitsui Chemicals (dynamic light scattering nanotrack particle size analyzer “Microtrack UPA-EX150 (made by Nikkiso Co., Ltd.)” 50% volume average particle diameter: 90-130 nm, concentration: 45.89% by weight) was used.

<Water-insoluble organic polymer particles-3>
As an aqueous dispersion (acrylic emulsion) of a polymethacrylic ester copolymer, PAN-9 manufactured by Mitsui Chemicals, Inc. (dynamic light scattering nanotrack particle size analyzer “Microtrack UPA-EX150 (made by Nikkiso Co., Ltd.)”) (Volume 50% average particle diameter: 50 nm, concentration: 45.35% by weight) was used.

<Preparation of metal oxide nanoparticle dispersion>
<Synthesis of titanium dioxide nanoparticles and preparation of dispersion>
7.5 ml (equivalent to 0.036 mol of Ti) of titanium oxychloride / hydrochloric acid aqueous solution (Fluka reagent hydrochloric acid: 38 to 42%, Ti: about 15%) was dissolved in 1000 ml of ion-exchanged water. Stir at a temperature of 70 ° C. After 5 hours, a bluish titanium dioxide colloidal aqueous solution was obtained.

  The pH of the aqueous colloidal solution was adjusted to around 2.5 by ion dialysis to obtain an aqueous dispersion of titanium dioxide having a solid concentration of 10% by weight. A part of the obtained aqueous dispersion was dropped onto a mesh to prepare an electron microscope observation sample, which was observed and confirmed to be a titanium dioxide crystal having an average particle diameter of 3 nm. The 50% volume average particle diameter (κ) measured by a dynamic light scattering nanotrack particle size analyzer “Microtrack UPA-EX150 (manufactured by Nikkiso Co., Ltd.)” was also 3 nm.

<Synthesis of zirconium dioxide-coated titanium dioxide ultrafine particles and preparation of aqueous dispersion>
Similar to the synthesis of titanium dioxide nanoparticles, a bluish titanium dioxide colloidal solution was obtained. To the colloidal solution, 6.4 parts by weight of zirconium oxychloride octahydrate (Zr: equivalent to 0.02 mol) was added, and the temperature of the reaction solution was kept at 70 ° C. and stirred for 2 hours. As a result, a bluish white slurry-like sol solution was obtained. The pH of the aqueous colloidal solution was adjusted to around 2.5 by ion dialysis to obtain an aqueous dispersion of zirconium dioxide-coated titanium dioxide having a solid content concentration of 10% by weight. A part of the obtained aqueous dispersion was dropped onto a mesh to prepare an electron microscope observation sample, which was observed and confirmed to be a titanium dioxide crystal having an average particle diameter of 3 nm. The 50% volume average particle diameter (κ) measured by a dynamic light scattering nanotrack particle size analyzer “Microtrack UPA-EX150 (manufactured by Nikkiso Co., Ltd.)” was 4 nm.
An amorphous coating layer was observed around a titanium dioxide crystal having a titanium dioxide crystal lattice spacing with an average particle diameter of 3 nm. The amorphous layer-covered titanium dioxide was found to be composed of Ti and Zr at a molar ratio of 1: 1.

  Further, X-ray diffraction spectrum measurement confirmed that amorphous zirconium dioxide was superimposed on titanium dioxide.

Example 1
(Preparation of polyolefin end-branched copolymer / titanium dioxide nanoparticle mixture)
While stirring the titanium dioxide nanoparticle dispersion liquid (solid content concentration 10% by weight) to 50 parts by weight (solid content 5.0 parts by weight), an aqueous dispersion (solid) of the polyolefin-based terminally branched copolymer (T) 10 wt%) was diluted with 27 parts by weight (solid content: 2.7 parts by weight) and further with 77.0 parts by weight of water to prepare a polyolefin end-branched copolymer / TiO 2 nanoparticle mixture. (Polyolefin end-branched copolymer / TiO2 = 35/65 weight ratio)
(Formation of polyolefin end-branched copolymer / titanium dioxide composite particles)
The composition was poured into a spray dryer, pressurized (0.2 MPa) at a nozzle outlet temperature of 190 ° C., and sprayed to obtain polyolefin-based terminally branched copolymer / titanium dioxide composite fine particles.

(Formation of titanium dioxide porous particles)
By heating the obtained polyolefin end-branched copolymer / titanium dioxide composite particles from room temperature to 600 ° C. at a rate of 5 ° C. per minute using an electric furnace, and further firing at 600 ° C. for 2 hours. The polyolefin end-branched copolymer was removed to obtain porous titanium dioxide particles.

(Example 2)
(Preparation of polymethacrylate copolymer / titanium dioxide nanoparticle mixture)
While stirring the titanium dioxide nanoparticle dispersion liquid (solid content concentration: 10% by weight) to 50 parts by weight (solid content: 5.0 parts by weight), polymethacrylic acid ester copolymer (acrylic emulsion) PAN-6 was added. It was diluted with 5.87 parts by weight (solid content: 2.7 parts by weight) and further with 96.3 parts by weight of water to prepare a polymethacrylic acid ester copolymer / TiO 2 nanoparticle mixed solution. (Polymethacrylate copolymer / TiO2 = 35/65 weight ratio)
(Formation of polymethacrylate copolymer / titanium dioxide composite particles)
The composition was poured into a spray dryer, pressurized (0.2 MPa) at a nozzle outlet temperature of 190 ° C., and sprayed to obtain polyolefin end-branched copolymer / titanium dioxide composite fine particles.

(Formation of titanium dioxide porous particles)
The obtained polymethacrylic acid ester copolymer / titanium dioxide composite particles are heated from room temperature to 600 ° C. at a rate of 5 ° C. per minute using an electric furnace, and further calcined at 600 ° C. for 2 hours. By removing the polymethacrylic acid ester copolymer, titanium dioxide porous particles were obtained.

(Example 3)
(Preparation of Polyolefin-based Branched Copolymer / Zirconium Dioxide-Coated Titanium Dioxide Nanoparticle Mixture)
While stirring the above-mentioned zirconium dioxide-coated titanium dioxide nanoparticle dispersion (solid content concentration: 10% by weight) to 67.2 parts by weight (solid content: 6.72 parts by weight), the polyolefin end-branched copolymer (T) The aqueous dispersion (solid content: 10% by weight) was diluted with 32.8 parts by weight (solid content: 3.28 parts by weight), and further with 77.0 parts by weight of water. A particle mixture was prepared. (Polyolefin end-branched copolymer / TiO2 system = 32.8 / 67.2 weight ratio)

(Formation of polyolefin end-branched copolymer / titanium dioxide composite particles)
This composition was poured into a spray dryer, pressurized (0.2 MPa) at a nozzle outlet temperature of 190 ° C., and sprayed to obtain polyolefin-based terminally branched copolymer / titanium dioxide composite fine particles.

(Formation of titanium dioxide-based porous particles)
The resulting polyolefin end-branched copolymer / titanium dioxide composite particles are heated from room temperature to 600 ° C. at a rate of 5 ° C. per minute using an electric furnace, and further calcined at 600 ° C. for 2 hours. By removing the polyolefin terminal branched copolymer, titanium dioxide porous particles were obtained.

Example 4
(Preparation of polymethacrylic acid ester copolymer / zirconium dioxide-coated titanium dioxide nanoparticle mixture)
While stirring the above-mentioned zirconium dioxide-coated titanium dioxide nanoparticle dispersion (solid content concentration 10% by weight) to 67.2 parts by weight (solid content 6.72 parts by weight), a polymethacrylate copolymer (acrylic emulsion) ) 7.23 parts by weight of an aqueous dispersion of PAN-9 (solid content: 3.28 parts by weight), further diluted with 77.0 parts by weight of water, and mixed with polymethacrylic acid ester copolymer / TiO 2 nanoparticles A liquid was prepared. (Polyolefin end-branched copolymer / TiO2 system = 32.8 / 67.2 weight ratio)

(Formation of polyolefin end-branched copolymer / titanium dioxide composite particles)
This composition was poured into a spray dryer, pressurized (0.2 MPa) at a nozzle outlet temperature of 190 ° C., and sprayed to obtain polyolefin-based terminally branched copolymer / titanium dioxide composite fine particles.

(Formation of titanium dioxide-based porous particles)
The obtained polymethacrylic acid ester copolymer / titanium dioxide composite particles are heated from room temperature to 600 ° C. at a rate of 5 ° C. per minute using an electric furnace, and further baked at 600 ° C. for 2 hours. As a result, the polymethacrylic ester copolymer was removed to obtain titanium dioxide porous particles.

(Example 5)
(Preparation of polyolefin-based terminally branched copolymer / YSZ nanoparticle mixture)
YSZ Nanoparticle Dispersion (Nissan Chemical Co., Ltd. Ultra Fine Particle Zirconia Sol # 1 Dynamic Light Scattering Nanotrack Particle Size Analyzer “Microtrack UPA-EX150 (Nikkiso Co., Ltd.)” 50% volume average particle size (κ ) While stirring 5 nm solid content concentration of 10% by weight to 28.4 parts by weight (solid content of 2.84 parts by weight), an aqueous dispersion of polyolefin-based terminally branched copolymer (T) (solid content of 10% by weight) %) Was further diluted with 11.6 parts by weight (solid content: 1.16 parts by weight) and 40.0 parts by weight of water to prepare a polyolefin end-branched copolymer / YSZ nanoparticle mixed solution. (Polyolefin end-branched copolymer / YSZ = 29/71 weight ratio)

(Formation of polyolefin-based terminally branched copolymer / YSZ composite particles)
This composition was poured into a spray dryer, pressurized (0.2 MPa) at a nozzle outlet temperature of 190 ° C., and sprayed to obtain polyolefin-based terminally branched copolymer / YSZ composite fine particles.

(Formation of YSZ porous particles)
Polyolefin end-branched copolymer / YSZ composite particles obtained were heated at a rate of 5 ° C. per minute from room temperature to 600 ° C. using an electric furnace, and further baked at 600 ° C. for 2 hours. The system branched end copolymer was removed to obtain YSZ porous particles.

(Comparative Example 1)
(Preparation of polyolefin-based terminally branched copolymer / YSZ nanoparticle mixture)
YSZ nanoparticle dispersion (Nanoparticle SZ-58YB (# 2), manufactured by Nissan Chemical Industries, Ltd.), secondary particle size: measured with a dynamic light scattering nanotrack particle size analyzer “Microtrack UPA-EX150 (manufactured by Nikkiso Co., Ltd.)” The polyolefin end-branched copolymer (T) was stirred while stirring 28.4 parts by weight (solid content 2.84 parts by weight) of 50% average particle size (κ) of 100 nm solid content of 10% by weight). 11.6 parts by weight (solid content: 1.16 parts by weight) and further diluted with 40.0 parts by weight of water to obtain a polyolefin-based terminally branched copolymer / YSZ nano A particle mixture was prepared. (Polyolefin end-branched copolymer / YSZ = 29/71 weight ratio)

(Formation of polyolefin-based terminally branched copolymer / YSZ composite particles)
This composition was poured into a spray dryer, pressurized (0.2 MPa) at a nozzle outlet temperature of 190 ° C., and sprayed to obtain polyolefin-based terminally branched copolymer / YSZ composite fine particles.

(Formation of YSZ porous particles)
Polyolefin end-branched copolymer / YSZ composite particles obtained were heated at a rate of 5 ° C. per minute from room temperature to 600 ° C. using an electric furnace, and further baked at 600 ° C. for 2 hours. The system branched end copolymer was removed to obtain YSZ porous particles.

(Comparative Example 2)
(Preparation of polyolefin end-branched copolymer / titanium dioxide nanoparticle mixture)
Titanium dioxide nanoparticle dispersion (manufactured by NanoTeK Co., Ltd., dynamic light scattering nanotrack particle size analyzer “Microtrac UPA-EX150 (Nikkiso Co., Ltd.)”) 50% volume average particle size (κ) is 40 nm solid content concentration 10 27% by weight (solid content: 10% by weight) of an aqueous dispersion (solid content: 10% by weight) of the polyolefin-based end-branched copolymer (T) while stirring to 50 parts by weight (5.0% by weight of solid content). : 2.7 parts by weight), and further diluted with 77.0 parts by weight of water to prepare a polyolefin-based terminally branched copolymer / TiO2 nanoparticle mixed solution. (Polyolefin end-branched copolymer / TiO2 = 35/65 weight ratio)

(Formation of polyolefin end-branched copolymer / titanium dioxide composite particles)
The composition was poured into a spray dryer, pressurized (0.2 MPa) at a nozzle outlet temperature of 190 ° C., and sprayed to obtain polyolefin-based terminally branched copolymer / titanium dioxide composite fine particles.

(Formation of titanium dioxide porous particles)
By heating the obtained polyolefin end-branched copolymer / titanium dioxide composite particles from room temperature to 600 ° C. at a rate of 5 ° C. per minute using an electric furnace, and further firing at 600 ° C. for 2 hours. The polyolefin end-branched copolymer was removed to obtain porous titanium dioxide particles.
The following evaluation was performed about the porous body obtained by the Example and the comparative example as mentioned above.

(1. Particle size)
Using a scanning electron microscope (JSM-6701F type manufactured by SEM / JEOL), observation was performed under the condition of 1.5 kV.

(2. Pore structure)
A cross-section of the particle was cut out by focused ion beam (FIB) processing, and the shape of the cross-section was observed using a transmission electron microscope (TEM / H-7650 manufactured by Hitachi, Ltd.) at 200 kV. The evaluation criteria are as follows.
◎ The pores have a regular structure (cubic phase structure) and are arranged.
○ Pore is confirmed but irregular × Pore cannot be identified by crystallites

(3. Specific surface area, pore volume, average pore size distribution)
Using autosorb 3 (manufactured by Kantachrome), nitrogen gas adsorption method at liquid nitrogen temperature (77K), specific surface area (m2 / g) (BET method), pore volume (ml / g) and average The pore size distribution (nm) (α) (BJH method) was measured. The porosity (volume%) was determined by [pore volume value / (pore volume value + 1 / metal oxide density) × 100].

(4. Crystallite size)
The crystallite size (β) was calculated by the Debye-Scherrer method (Debye-Scherrer method) as measured by a powder X-ray analyzer (Rigaku MultiFrex, CuKα ray: 1.5418 mm).

Claims (13)

The manufacturing method of the metal oxide porous body containing following process (a), (b) and (c).
Step (a): A mixed liquid containing organic polymer particles dispersible in an aqueous medium, metal oxide nanoparticles, and an aqueous medium is prepared.
(Here, 50% volume average particle diameter measured by dynamic light scattering particle size distribution system of metal oxide nanoparticles is κ, and 50% volume average particle diameter measured by dynamic light scattering particle size distribution system of organic polymer particles. Where γ is γ <γ.)
Step (b): The mixed liquid obtained in the step (a) is dried to obtain an organic-inorganic composite. Step (c): The organic polymer particles are removed from the organic-inorganic composite to obtain a metal oxide porous body that satisfies the following requirements (i), (ii), and (iii).
Requirement (i): α> β
(Α is the average pore diameter determined from BJH analysis by nitrogen adsorption method, and β is the crystallite size of the metal oxide on the pore wall determined by Debye-Scherrer method of powder X-ray analysis.)
Requirement (ii) The BET specific surface area by nitrogen adsorption method is 50 m ² / g or more.
Requirement (iii) The porosity is 50% by volume or more. The method for producing a metal oxide porous body according to claim 1, wherein γ is 10 to 300 nm and β <γ. The method for producing a metal oxide porous body according to claim 1, wherein the κ is 1 to 50 nm. Said alpha is 10-300 nm, The manufacturing method of the metal oxide porous body in any one of Claims 1-3 characterized by the above-mentioned. The method for producing a metal oxide porous body according to any one of claims 1 to 4, wherein the metal oxide porous body has mesopores, and the pore structure thereof is a cubic phase structure. Metal oxide nanoparticles are silicon (Si), titanium (Ti), zirconium (Zr), yttrium (Y), barium (Ba), aluminum (Al), tin (Sn), hafnium (Hf), antimony (Sb). And a metal selected from the group consisting of zinc (Zn), indium (In), lead (Pb), cobalt (Co), lithium (Li), iron (Fe), and manganese (Mn). The manufacturing method of the metal oxide porous body in any one of Claims 1-5. Organic polymer particles that can be dispersed in aqueous media are polyolefin, poly (meth) acrylic ester, polystyrene, polyurethane, polyacrylonitrile, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polybutadiene The method for producing a metal oxide porous body according to claim 1, wherein the water-insoluble polymer particles are selected from the group consisting of: The organic polymer particles dispersible in an aqueous medium are terminally branched polyolefin copolymer particles having a number average molecular weight represented by the following general formula (1) of 2.5 × 10 ⁴ or less. Item 8. A method for producing a metal oxide porous body according to any one of Items 1 to 7.
(In the formula, A represents a polyolefin chain. R ¹ and R ² represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them is a hydrogen atom. X ¹ and X ² are the same. Or, differently, it represents a group having a linear or branched polyalkylene glycol group. In the terminal branched copolymer represented by the general formula (1), X ¹ and X ² are the same or different, and the general formula (2)
(In the formula, E represents an oxygen atom or a sulfur atom. X ³ represents a polyalkylene glycol group or the following general formula (3).
(In the formula, R ³ represents an m + 1 valent hydrocarbon group. G is the same or different and is represented by —OX ⁴ , —NX ⁵ X ⁶ (X ^{4 to} X ⁶ represent a polyalkylene glycol group). M represents the number of bonds between R ³ and G, and represents an integer of 1 to 10). )
Or general formula (4)
(Wherein X ⁷ and X ⁸ are the same or different and represent a polyalkylene glycol group or a group represented by the above general formula (3)). 9. A method for producing a porous material. The method for producing a metal oxide porous body according to claim 8 or 9, wherein the terminally branched copolymer is represented by the following general formula (1a) or general formula (1b):
(In the formula, R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them is a hydrogen atom. R ⁶ and R ⁷ represent a hydrogen atom or a methyl group, At least one of them is a hydrogen atom, R ⁸ and R ⁹ represent a hydrogen atom or a methyl group, and at least one of them is a hydrogen atom, l + m represents an integer of 2 to 450, n is 20 Represents an integer of 300 or more.)
(In the formula, R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and at least one of them is a hydrogen atom. R ⁶ and R ⁷ represent a hydrogen atom or a methyl group, At least one of them is a hydrogen atom, R ⁸ and R ⁹ represent a hydrogen atom or a methyl group, at least one of them is a hydrogen atom, R ¹⁰ and R ¹¹ represent a hydrogen atom or a methyl group, At least one of them is a hydrogen atom, l + m + o represents an integer of 3 to 450, and n represents an integer of 20 to 300.) The method for producing a metal oxide porous body according to any one of claims 1 to 7, wherein the organic polymer particles are (meth) acrylic acid ester polymer particles. The method for producing a metal oxide porous body according to any one of claims 1 to 11, wherein the step (b) is a step of drying the mixed solution by a spray dryer method to form a particulate organic-inorganic composite. . The said process (b) is a process of apply | coating the said liquid mixture on a base material, and drying, and forming a film-form organic inorganic composite, The metal oxide porous body in any one of Claims 1-11 Manufacturing method.