JP4290930B2 - Composition for forming porous body, porous body, and method for producing porous body - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to microcapsules that are primarily used to form porous ceramic products.
[0002]
[Prior art]
Ceramic products such as ceramics, ceramics, porcelain, bricks, tiles, blocks, insulators, cement, plaster, firewood, polishing tools, etc., which are porous, have excellent characteristics such as light weight, high heat insulation, and high insulation. Therefore, it is widely used in various industrial fields.
[0003]
These porous bodies are produced by producing bubbles in the composition for forming a porous body when a porous body is produced, or by adding hollow fillers such as glass balloons and resin balloons. The
[0004]
[Problems to be solved by the invention]
However, when the porous body is produced by the method as described above, the following problems may occur.
[0005]
First, in the method of generating bubbles, it may be difficult to produce a porous body having an average pore diameter of 30 μm or less, and particularly 10 μm or less is difficult.
[0006]
Second, when a hollow filler is used, the density is different from the hollow filler and the base material, so the workability is insufficient, uniform mixing is difficult, and the pores are uniformly distributed. In some cases, it was difficult to manufacture the body.
[0007]
Thirdly, it may be difficult to control the pore size distribution of the porous body by the conventional method. For example, pores having a large pore size may be included in the porous body.
[0008]
In view of the above situation, an object of the present invention is to produce a porous body in which pores that are sufficiently small and have a monodispersed pore size distribution are uniformly distributed with good productivity.
[0009]
[Means for Solving the Problems]
According to the present invention for achieving the above object, a microcapsule for forming a porous body containing at least a high-boiling medium that is combustible and / or volatile and has a boiling point of 50 ° C. or higher , a base material, and curing There is provided a porous body-forming composition comprising a high-temperature adhesive having a temperature of 100 ° C or higher .
[0010]
According to the present invention, a microcapsule for forming a porous body is used. In this case, by using a microcapsule for forming a porous body having a volume average average particle diameter of 1 to 30 μm, fine pores that are difficult to realize by the method of generating pores by generating bubbles, specifically A porous body having minute pores with a volume average average pore diameter of 1 to 30 μm can be produced.
[0011]
Furthermore, it is also possible to produce microcapsules for forming a porous material as necessary. For example, the microparticles having an average particle diameter (volume average) of 20 μm or less, further 10 μm or less, or 5 μm or less. A microcapsule for forming a porous body can also be prepared. If such a microcapsule for forming a porous body is used, the average pore diameter (volume average) is 20 μm or less, and further has pores of 10 μm or less or 5 μm or less. A porous body can be produced.
[0012]
In addition, unlike a hollow filler, in the case of a microcapsule for forming a porous body, since a capsule having a wide range of mass can be realized, a dispersion failure due to a difference in density from the base material can be suppressed, and the porous body The forming microcapsules and the base material can be uniformly mixed with good workability, and a uniform porous body-forming composition can be obtained. Therefore, if such a composition for forming a porous body is fired, a porous body in which pores are substantially uniformly distributed in the substrate can be obtained.
[0013]
In addition, if a microcapsule for forming a porous body is used, a capsule with a controlled particle size distribution can be produced. Therefore, a porous material having a monodispersed pore size distribution that is difficult to realize by the method of generating bubbles by generating bubbles. A mass can be obtained. For example, it is possible to produce a microcapsule for forming a porous body in which the proportion of particles having a particle size of 10 times or more the average particle size in the entire microcapsule is 1% by volume or less. By using the body-forming microcapsules, it is possible to produce a porous body in which the ratio of the pores having a pore diameter 10 times or more the average pore diameter to the whole pores is 1% by volume or less.
[0014]
The average particle size and particle size distribution of the microcapsules can also be measured using, for example, a Coulter Multisider manufactured by Coulter Electronics (UK).
[0015]
The state of the pores in the porous body can be analyzed by observing the porous body with an electron microscope or the like and measuring the pores.
[0016]
As a result, a porous body in which pores that are sufficiently small and have a monodisperse pore size distribution can be uniformly distributed can be produced with good productivity.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
[0018]
(Microcapsule for porous body formation)
A microcapsule for forming a porous body can be produced by a method using mainly a chemical reaction, such as an interfacial polymerization method, an in situ polymerization method, a submerged curing coating method, or a coacervation method. The interfacial polymerization method and the in situ polymerization method are preferable because the structure of the microcapsules can be precisely controlled.
[0019]
In the interfacial polymerization method, the raw material for the capsule resin wall exists in both the microcapsule internal medium and the microcapsule external medium, and is included in the microcapsule internal medium and the microcapsule external medium. The encapsulated resin wall is formed by reacting with the raw material.
[0020]
On the other hand, in the in situ polymerization method, the raw material for the capsule resin wall exists only in either the internal medium of the microcapsule or the external medium of the microcapsule, and only the raw material contained in the internal medium of the microcapsule reacts. Then, the capsule resin wall is formed, or only the raw material contained in the external medium of the microcapsule reacts to form the capsule resin wall.
[0021]
The capsule resin wall is not particularly limited as long as it burns when the composition for forming a porous body is fired, and may be any of thermosoftening and thermosetting. Select in consideration of the capsule structure. Among them, for reasons such as easy control of the structure of the microcapsule, urea resin, melamine resin, polyurethane resin, urethane-urea resin, polyamide resin, polyester resin, polyether resin, polyolefin resin, polysulfonamide resin, polysulfonate resin, Epoxy resins, polycarbonate resins, phenol resins, and the like are preferable, and two or more kinds of resins can be used in combination as necessary.
[0022]
Specifically, for example, when the capsule resin wall is made from a urea resin, an in situ polymerization method using a methylolated urea compound, an interfacial polymerization method using a urea compound and formaldehyde, a carbonyl halide compound and an amine. It can be produced by an interfacial polymerization method using the like.
[0023]
Moreover, when producing a capsule resin wall from a melamine resin, it can be produced by an in situ polymerization method using a methylolated melamine compound, an interfacial polymerization method using a melamine compound and formaldehyde, or the like.
[0024]
When the capsule resin wall is made of a polyurethane resin, an interfacial polymerization method using an isocyanate compound and a hydroxyl compound, an interfacial polymerization method using a carbonyl monooxy compound and an amine, and an amino-carbonyl monooxy compound are used. It can be produced by the in situ polymerization method used.
[0025]
Moreover, when producing the capsule resin wall from urethane-urea resin, it can be produced by an interfacial polymerization method using an isocyanate compound and water, an interfacial polymerization method using an isocyanate compound and amines, or the like.
[0026]
When the capsule resin wall is made from a polyamide resin, it can be made by an in situ polymerization method using an amino acid derivative, an interfacial polymerization method using a carboxylic acid derivative and amines, or the like.
[0027]
When the capsule resin wall is made from a polyester resin, it can be made by an interfacial polymerization method using a carboxylic acid derivative and a hydroxyl compound.
[0028]
When the capsule resin wall is made from a polyether resin, it can be made by an interfacial polymerization method using a carboxylic acid derivative and a hydroxyl compound.
[0029]
When the capsule resin wall is made from a polyolefin resin, it is made by an in situ polymerization method using ethylene, propylene, styrene, (meth) acrylic acid, (meth) acrylic acid ester, vinyl acetate, styrene-divinylbenzene, or the like. it can.
[0030]
When the capsule resin wall is made from a polysulfonamide resin, it can be made by an interfacial polymerization method using a sulfonic acid derivative and an amine.
[0031]
When the capsule resin wall is made from a polysulfonate resin, it can be made by an interfacial polymerization method using a sulfonic acid derivative and a hydroxyl compound.
[0032]
Moreover, when producing the capsule resin wall from an epoxy resin, it can be produced by an interfacial polymerization method using an epoxide and a hydroxyl compound, an interfacial polymerization method using an epoxide and an amine, or the like.
[0033]
When the capsule resin wall is made from a polycarbonate resin, it can be made by an interfacial polymerization method using a hydroxy compound and a carbonyl halide compound.
[0034]
When the capsule resin wall is made from a phenol resin, it can be made by an interfacial polymerization method using an aromatic hydroxy compound and formaldehyde, an interfacial polymerization method using a urea compound and an aromatic hydroxy compound, or the like.
[0035]
As the raw material for the capsule resin wall, in addition to the above, polyisocyanate, polyisothiocyanate, polyamine, polycarboxylic acid, polybasic acid chloride, acid anhydride, epoxy compound, polyol, (meth) acrylic compound, polysulfide, Organic amines, acid amides, water-soluble epoxy compounds, phenols, formalin, phosgene, spiroacetal heterocyclic amines, aldehydes, and the like can also be used.
[0036]
Among the capsule resin walls described above, melamine resin, urea resin, epoxy resin, phenol resin, and the like are thermosetting resins. Polyurethane resins, urethane-urea resins, polyamide resins, polyester resins, polyether resins, polyolefin resins, polysulfonamide resins, polysulfonate resins, polycarbonate resins, and the like are thermosoftening resins.
[0037]
In addition, when producing the microcapsules for forming a porous body, an anionic monomer, a cationic monomer, a nonionic monomer, an anionic polymer, a cationic polymer, a nonionic heavy as necessary. Use a surfactant such as coalescence.
[0038]
Specifically, alkylbenzene sulfonates such as sodium benzenesulfonate and sodium dodecylbenzenesulfonate, polyoxyethylene sulfate, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride An acid copolymer, poly (meth) acrylic acid, polyvinyl alcohol, hexaethylcellulose, methylcellulose, carboxymethylcellulose, kaizen, gum arabic, gelatin, funnel oil and the like are used.
[0039]
In addition, the amount of the surfactant used is preferably 0.5% by mass or more, more preferably 1% by mass or more, and on the other hand, 10% by mass or less is preferable, and 5% by mass or less with respect to the entire encapsulation reaction. Is more preferable.
[0040]
In the encapsulation reaction described above, the reaction temperature is usually 50 to 100 ° C.
[0041]
(Inclusive of microcapsules for porous body formation)
The microcapsules for forming a porous body contain at least a high boiling point medium that is combustible and / or volatile and has a boiling point of 50 ° C. or higher. When the composition for forming a porous body is fired, the high boiling point medium is burned and / or volatilized together with the capsule resin wall to form a cavity. As a result, a large number of holes are formed. In addition, in order to suppress that the high boiling point medium volatilizes during the production of the microcapsules for forming the porous body and the denseness of the capsule resin wall is reduced, a high boiling point medium having a boiling point of 50 ° C. or higher is used.
[0042]
Such a high boiling point medium is not particularly limited as long as it is burned and / or volatilized during firing of the composition for forming a porous body, but from the viewpoint of manufacturability of microcapsules for forming a porous body, For example, flammable and / or volatile solvents such as benzene, toluene, xylene, MEK, MIBK, and hexane can be used.
[0043]
Also, combustible and / or volatile plasticizers can be used.
[0044]
Examples of such plasticizers include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), diheptyl phthalate (DHP), di-2-ethylhexyl phthalate (DOP), and di-n-octyl. Phthalates such as phthalate, diisodecyl phthalate, butyl benzyl phthalate, diisononyl phthalate, ethyl phthalyl ethyl glycolate; trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP), tri-2-ethylhexyl phosphate ( TOP), tributoxyethyl phosphate, trioleyl phosphate, triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (T P), cresyl diphenyl phosphate (CDP), xylenyl diphenyl phosphate (XDP), phosphate esters such as 2-ethylhexyl diphenyl phosphate; trimellitic esters such as tri-2-ethylhexyl trimellitate; butyl benzoate Benzoic acid esters such as hexyl benzoate; salicylic acid esters such as isoamyl salicylate, benzyl salicylate, methyl salicylate, ethyl salicylate; dimethyl adipate (DMA), diisobutyl adipate (DIBA), dibutyl adipate (DBA), di-2-ethylhexyl Adipate (DOA), diisodecyl adipate, dibutyl diglycol adipate, dibutyl diglycol adipate, di-2-ethylhexyl azate, dimethyl sebake Fatty acid esters such as dibutyl sebacate, di-2-ethylhexyl sebacate, methylacetylricinoleate; aliphatic dicarboxylic acid esters such as dibutyl fumarate, diethyl malonate, dimethyl oxalate; o-acetyltriethyl citrate Citric acid esters such as methylnaphthalene, dimethylnaphthalene, monoisopropylnaphthalene, diisopropylnaphthalene, and other alkylnaphthalenes; o-methyldiphenyl ether, m-methyldiphenyl ether, alkyldiphenyl ethers such as p-methyldiphenyl ether; N, N-dimethyl Amide compounds of higher fatty acids or aromatic sulfonic acids such as laurylamide and N-butylbenzenesulfonamide; trimellitic acid esters such as trioctyl trimellitate; dimethyl Diarylalkanes such as diarylmethane such as rudiphenylmethane, diarylethane such as 1-phenyl-1-methylphenylethane, 1-dimethylphenyl-1-phenylethane, 1-ethylphenyl-1-phenylethane; chlorinated paraffins Acrylic acid ester polymerizable compounds, acrylamide polymerizable compounds, methacrylic acid polymerizable compounds, methacrylic acid ester polymerizable compounds, methacrylamide polymerizable compounds, maleic anhydride polymerizable compounds, maleic acid ester polymerization A vinyl polymerizable medium such as a polymerizable compound, a styrene-based polymerizable compound, a vinyl ether-based polymerizable compound, a vinyl ester-based polymerizable compound, and an allyl ether-based polymerizable compound.
[0045]
A non-combustible compound such as a halogen-containing compound can be used as a high boiling point medium as long as it volatilizes at the firing temperature.
[0046]
(Porous body)
In the production of the porous body , first, at least the microcapsules for forming the porous body and the base material are mixed, and this mixture is molded to produce a temporary molded body. At this time, the high-boiling-point medium is formed under the conditions that the microcapsules for forming the porous body are not greatly deformed, the capsule resin wall is not cracked, and part of the capsule resin wall is not destroyed. Is not released from the microcapsules for forming a porous body.
[0047]
In some cases, the porous body-forming microcapsules may be in a dried form and mixed with the base material, or the slurry containing the porous body-forming microcapsules may be mixed with the base material. There is also. When the slurry is used, the temporary molded body can be more satisfactorily produced due to the presence of the liquid. Moreover, the use of the slurry can suppress breakage of the microcapsules for forming the porous body.
[0048]
The temporary molded body thus obtained is fired to burn and / or volatilize the high boiling point medium and the porous body forming microcapsules. When the high-boiling medium and the microcapsules for forming a porous body are burned and / or volatilized, the portion becomes a cavity and a large number of pores are formed. At the same time, the base material is fused or sintered to form a final molded body.
[0049]
However, a porous material for forming microcapsules, on the substrate material, further, the curing temperature you mixed with 100 ° C. or higher high-temperature adhesive. And this mixture is temporarily molded on the conditions that a high boiling point medium is not discharge | released, and a temporary molded object is baked at 100 degreeC or more.
[0050]
When a high temperature adhesive is used, the high boiling point medium and the microcapsules for forming the porous body are burned and / or volatilized at the same time as the high temperature adhesive is melted, the base material is bonded, and final molding is performed. The body is formed.
[0051]
As such a high temperature adhesive, for example, solder glass, low melting glass adhesive, alkali metal silicate inorganic adhesive, phosphate inorganic adhesive, silica inorganic adhesive, alumina inorganic adhesive, Use zirconia inorganic adhesive.
[0052]
The base material includes silicates such as silicate and aluminosilicate, and precursors thereof; solid metal oxides such as aluminum oxide, zinc oxide, titanium oxide, and magnesium oxide; and Precursors: non-oxide materials such as carbides, nitrides, borides, silicides and their precursors; natural products such as clay, silica, limestone, minerals, etc. are used.
[0053]
The firing temperature is a temperature range in which the capsule resin walls and inclusions of the microcapsule for forming a porous body are sufficiently burned and volatilized, and when a high temperature adhesive is used, a temperature range in which the high temperature adhesive sufficiently melts. And selected according to the base material. For example, the temperature is set to 100 to 500 ° C. in the case of low temperature baking, and 500 to 2000 ° C. in the case of high temperature baking.
[0054]
Multi porous-forming microcapsules, ceramic, earthenware, porcelain, brick, tile, block, insulator, rasp, is suitable for the production of ceramic products of the porous body, such as grinding equipment, light weight, high thermal insulation, high Insulation can be realized.
[0055]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not restrict | limited to a following example. Unless otherwise specified, commercially available high-purity products were used as reagents.
[0056]
(Example 1) Porous body 1
15 parts by mass of a ring-opened product (weight average molecular weight: 350,000, maleic anhydride ring-opening rate: 70%) of a styrene-maleic anhydride copolymer by partial hydrolysis of maleic anhydride is added to 285 parts by mass of water. Dissolved. To this, 200 parts by mass of dibutyl phthalate was added and emulsified for 3 minutes using a homomixer. 65 parts by mass of trimethylol melamine initial polymer (trade name: Milben Resin 512, manufactured by Showa Kogyo Co., Ltd.) was mixed with the obtained emulsion and stirred at 80 ° C. for 2 hours using a propeller-type stirrer, followed by encapsulation reaction And a slurry containing 43% by mass of the microcapsule 1 for forming a porous body was obtained.
[0057]
When the obtained microcapsules 1 for forming a porous body were analyzed, the average particle size (volume average) was 2 μm, and the content of capsules having a particle size of 20 μm or more was 0.2% by mass.
[0058]
55 parts by mass of the slurry containing the above microcapsules 1 for forming a porous body, 75 parts by mass of glass powder, and 150 parts by mass of titania were mixed. Mixability was good. The obtained mixture was poured into a mold with care so that the porous body-forming microcapsules 1 were not broken, and dried to prepare a temporary molded product. Thereafter, the temporarily molded product was baked at 800 ° C. for 1 hour to obtain a porous body 1.
[0059]
When the obtained porous body 1 was analyzed, the pores were uniformly dispersed, the average pore diameter (volume average) of the pores was 1.8 μm, and the ratio of the pores having a pore diameter of 18 μm or more to the whole pores was 0.00. It was 1% by volume.
[0060]
(Comparative example 1) Porous body 2
20 parts by mass of a commercially available glass balloon, 75 parts by mass of glass powder, and 150 parts by mass of titania were mixed. The glass balloon had a low bulk density and poor mixing. The obtained mixture was put into a mold and baked at 800 ° C. for 1 hour to obtain a porous body 2.
[0061]
When the obtained porous body 2 was analyzed, a large number of holes were formed in the upper part of the molded product, and the average hole diameter (volume average) of the holes was 58 μm, and the ratio of the holes having a hole diameter of 580 μm or more to the whole hole was 3.7% by volume.
[0062]
【The invention's effect】
By using the composition for forming a porous body of the present invention, a porous body in which pores that are sufficiently small and the pore size distribution is monodispersed can be uniformly distributed can be produced with good productivity.

Claims (5)

A microcapsule for forming a porous body, which is combustible and / or volatile and contains at least a high boiling point medium having a boiling point of 50 ° C. or higher , a base material, and a high temperature adhesive having a curing temperature of 100 ° C. or higher. A composition for forming a porous body . The microcapsule for forming a porous body is,
The average particle diameter (volume average) is 1 to 30 μm,
2. The porous body-forming material according to claim 1, wherein a ratio of the particles having a particle diameter of 10 times or more of the average particle diameter to the whole microcapsules for forming the porous body is 1% by volume or less. Composition . The porous body-forming composition according to claim 1 or 2 is formed by firing, mainly comprising a substrate having pores that are substantially uniformly distributed;
The average pore diameter (volume average) of the pores is 1 to 30 μm,
The porous body whose ratio which the hole which has a hole diameter 10 times or more of this average hole diameter occupied to this whole hole is 1 volume% or less. At least a microcapsule for forming a porous body containing at least a combustible and / or volatile high boiling point medium having a boiling point of 50 ° C. or higher , a base material, and a high temperature adhesive having a curing temperature of 100 ° C. or higher. Mixing, and
A step of forming the mixture without substantially releasing the high boiling point medium to produce a temporary molded body;
The temporary molded body is baked at 100 ° C. or higher, the high-boiling medium and the porous body-forming microcapsules are burned and / or volatilized, the high-temperature adhesive is melted, and the base material is bonded to the final product. The manufacturing method of the porous body including the process of producing a molded object. The microcapsule for forming a porous body is,
The average particle diameter (volume average) is 1 to 30 μm,
5. The production of a porous body according to claim 4, wherein a ratio of the particles having a particle diameter of 10 times or more of the average particle diameter to the entire microcapsules for forming the porous body is 1% by volume or less. Method.