JP3423050B2 - Method for producing inorganic powder-containing porous polymer and method for producing inorganic porous body - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a porous polymer containing an inorganic powder in which a large amount of a silicate powder is filled in a polymer and a method for producing an inorganic porous material obtained by firing the same. It is a thing.

[0002]

It is well known that a W / O type emulsion comprising a polymerizable monomer, water, an emulsifier and a polymerization initiator is polymerized and cured and then water is removed to obtain a porous polymer. There is. Utilizing this fact, a method for producing an inorganic-containing porous polymer from a W / O type emulsion containing an inorganic powder (Japanese Patent Publication No. 55-44769) or a W / O type emulsion is used. A method for producing a ceramic porous body by firing the inorganic-containing porous polymer described above (JP-A-63-270368, JP-A-2-120285) and the like have been proposed.

However, when a silicate powder is used as the inorganic powder, it is difficult to form a W / O type emulsion when the amount of silicate added is large, and even if a W / O type emulsion is obtained, the emulsion is not formed. There is a problem that the W / O type emulsion is extremely unstable, and the emulsion collapses during polymerization and curing, and it is difficult to obtain a polymer having fine and uniform pores. Moreover, when a porous polymer having a low content of silicate powder is fired, cracks and blisters are likely to occur.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing a porous polymer in which a large amount of silicate powder is filled in the polymer by using a W / O type emulsion. Secondly, it is an object of the present invention to provide a method for producing an inorganic porous body made of silicate powder and free from cracks and blisters.

[0005]

According to the present invention, a W / O type emulsion consisting of an inorganic powder, a polymerizable unsaturated compound, an emulsifier, a polymerization initiator and water is polymerized and cured, and then water is removed. In the method for producing a porous polymer containing an inorganic powder, a silicate powder surface-treated with an organosilicon compound represented by the following chemical formula 1 is used as the inorganic powder. A method for producing a polymer is provided,

[0006]

[Chemical 2]

Furthermore, there is provided a method for producing a porous polymer containing an inorganic powder, wherein the silicate powder is at least one selected from glass, cordierite, clay, kaolin, and mica. Further, a method for producing an inorganic porous material, which comprises firing the inorganic powder-containing porous polymer containing 60% by weight or more of the inorganic powder with respect to the total amount of the inorganic powder, the polymerizable unsaturated compound and the emulsifier. Will be provided.

That is, when a silicate powder surface-treated with a specific organosilicon compound is used, a stable W containing a large amount of silicate powder dispersed in a polymerizable unsaturated compound as an oil phase is used.
/ O-type emulsion is produced, and the object of the first invention can be achieved by polymerizing and curing the W / O-type emulsion, and then drying the resulting porous polymer. The inventors have found that the object of the invention can be achieved, and have reached the present invention.

The present invention will be described in detail below. The silicate powder in the present invention, glass, cordierite, clay, kaolin, mica, porcelain stone, wax stone, montmorillonite, mullite, sillimanite, steatite,
Examples thereof include forsterite, wollastonite, zircon, and the like, but it is also possible to use a silicate mineral that becomes a ceramic by firing, or a silicate compound obtained by synthesis. Among them, glass, cordierite,
Clay, mica, and kaolin are preferable because the effect of the surface treatment of the organosilicon compound is likely to be exhibited, and glass and cordierite are particularly preferable when the inorganic porous body is used because of its wide use. These can also be used by appropriately mixing them.

The organosilicon compound used for the surface treatment of the above-mentioned silicate powder has at least one alkoxyl group directly bonded to a silicon atom and has a silicon atom as shown in the following chemical formula (Chemical formula 3). To have at least one organic group having 2 or more carbon atoms directly bonded to the carbon atom.

[0011]

[Chemical 3]

Examples of the organosilicon compound satisfying such a condition include ethyltriethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, which has three alkoxyl groups and one organic group having 2 or more carbon atoms, Hexyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, trimethoxyvinylsilane, triethoxyvinylsilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 2-aminoethylaminopropyltrimethoxysilane, 3- (2-aminoethylaminopropyl) trimethoxysilane, 3- [2- (2-aminoethylaminoethylamino) propyl] trimethoxysilane, 3-benzyl Roh trimethoxysilane,
Trialkoxysilanes such as 3-cyclohexylaminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane, or two alkoxyl groups and two organic groups, and at least one of the two organic groups
Dialkoxysilanes such as dimethoxydiphenylsilane, dimethoxymethylphenylsilane, 3-aminopropyldiethoxymethylsilane, and 3- (2-aminoethylaminopropyl) dimethoxymethylsilane, each of which is an organic group having 2 or more carbon atoms, or It has one alkoxyl group and three organic groups, and at least one of the three organic groups
Methoxydimethylvinylsilane, ethoxydimethylvinylsilane, methoxytripropylsilane, dimethylethoxyphenylsilane, each of which is an organic group having 2 or more carbon atoms,
Examples thereof include monoalkoxysilanes such as diphenylethoxymethylsilane, diphenylethoxyvinylsilane, ethoxytriphenylsilane, benzyldimethylethoxysilane, 3-aminopropyldimethylethoxysilane and dimethylethoxy-3-glycidoxypropylsilane.

Among them, ethyltriethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, hexyltri, in which the organic group having 2 or more carbon atoms is an alkyl group having 2 to 10 carbon atoms, phenyl group, benzyl group or acryloyl group. Methoxysilane, methoxytripropylsilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethoxydiphenylsilane, dimethoxymethylphenylsilane, dimethylethoxyphenylsilane, ethoxytriphenylsilane, benzyldimethylethoxysilane, 3-methacryloxypropyltrimethoxysilane And the like. Particularly, the organic group having 2 or more carbon atoms is an alkyl group having 2 to 10 carbon atoms, a phenyl group or an acryloyl group, and ethyltriethoxyoxy having 2 or more alkoxyl groups. Emissions, triethoxysilane, butyl trimethoxysilane, hexyl trimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethoxy diphenyl silane, dimethoxy methyl phenyl silane, 3-methacryloxypropyl trimethoxy silane are preferred. It should be noted that these may be used in an appropriate mixture.

On the other hand, when tetraalkoxysilanes such as tetraethoxysilane which are outside the scope of the present invention, tetraalkyl (aryl) silanes such as phenyltrimethylsilane, or methylalkoxysilanes such as methyltriethoxysilane are used. , A W / O type emulsion in which silicate powder is mixed and dispersed in the oil phase is not produced or is unstable even if produced, and a large amount of oil phase (polymerizable unsaturated compound, emulsifier) is required, A porous polymer containing inorganic powder cannot be obtained.

The surface treatment of the silicate powder with the organosilicon compound represented by the chemical formula 1 is carried out in the same manner as a well-known method for treating a silane coupling agent to an inorganic filler. be able to. For example, silicate powder is dispersed in water or an organic solvent, and if necessary, the pH of the solution is adjusted to 3 to 5, and then an organosilicon compound is added while stirring, dehydration and heat drying are performed. Examples thereof include a wet method and a dry method in which a silicate powder in a stirring state is sprayed with an organic silicon compound aqueous solution having an optimum concentration, mixed and stirred, and then heated and dried for treatment.
The amount of the organosilicon compound added is 10% in order to obtain a sufficient hydrophobic effect on the surface of the silicate powder.
0.1 to 3 parts by weight is preferable with respect to 0 parts by weight.

The polymerizable unsaturated compound in the present invention is a compound having a polymerizable double bond in the molecule and capable of radical polymerization or redox polymerization and capable of forming a W / O type emulsion with water. If there is no particular limitation. Examples of such a polymerizable unsaturated compound include styrene and α
-Methylstyrene, divinylbenzene, methyl methacrylate, ethylene glycol di (meth) acrylate,
(Meth) acrylic acid esters such as trimethylolpropane tri (meth) acrylate, diallyl phthalate,
Examples thereof include acrylonitrile and unsaturated polyesters, and among them, styrene or a mixture of the polymerizable unsaturated compounds containing styrene as a main component is preferable. These can be used alone or in appropriate combination.

As the emulsifier, one having a function of forming a W / O type emulsion which is well known and widely used in the past is used. Such emulsifiers include H.264. L. B. There are surface active agents having a ratio of about 3.5 to 6.0, for example, higher fatty acid esters of sorbitan such as sorbitan sesquioleate, sorbitan monooleate and sorbitan monostearate, higher fatty acid esters such as glycerol stearate and polyglycerol oleate. Can be given. These can also be used in appropriate combination. The amount of such an emulsifier used is 10 to 50 parts by weight, particularly 20 to 30 parts by weight based on 100 parts by weight of the polymerizable unsaturated compound.
It is preferable for producing a type emulsion and obtaining an inorganic powder-containing porous polymer having an appropriate strength.

As the polymerization initiator, usual radical polymerization initiators and redox catalysts can be used without particular limitation.
It is preferable to use a radical polymerization catalyst or a redox catalyst that operates at 100 ° C. or lower in order to avoid remarkable phase separation of the W / O type emulsion and evaporation of water. Examples of these are hydrogen peroxide, ammonium persulfate, potassium persulfate, benzoyl peroxide, lauroyl peroxide, t-butyl peroxyoctoate, p-menthane hydroperoxide, di-myristyl peroxydicarbonate,
Peroxide radical polymerization initiators such as 1,1-bis (t-butylperoxy) cyclohexane, azo radical polymerization initiators such as azobisisobutyronitrile and azobis-2,4-dimethylvaleronitrile, or these And a redox polymerization catalyst of the radical polymerization initiator of 1) with an amine compound, an organometallic compound, and the like. The addition amount of the polymerization initiator is preferably 0.05 to 5 parts by weight with respect to 100 parts by weight of the polymerizable unsaturated compound.

Further, as the reinforcing material, various fibers, whiskers and the like can be added to such an extent that the formation or stability of the W / O type emulsion is not significantly adversely affected.

The method for producing the inorganic powder-containing porous polymer of the present invention will be described below step by step. First, a silicate powder surface-treated with the above organosilicon compound,
A polymerizable unsaturated compound, an emulsifier, a polymerization initiator and water are mixed to form a W / O type emulsion. At this time, there is no particular limitation on the order of addition of each raw material, and mixing,
For stirring, a stirrer having a stirrer cross type, a propeller type, a turbine type, or the like, a mixer such as a ball mill or a colloid mill, or a kneader such as a kneader or a screw extruder can be used.

At this time, the amounts of silicate powder, polymerizable unsaturated compound and water used are 100: 20 to 60:10 by weight.
300, especially 100: 30 to 50:30 to 200 is desirable, and the W / O type emulsion obtained with the composition ratio in this range is stable, and its polymer has an appropriate strength. On the other hand, if the amount of the polymerizable unsaturated compound used is too small, or if the amount of water used is too large, it becomes difficult to produce a W / O type emulsion, and the strength of the polymer is reduced to achieve the object of the present invention. It is not preferable because it cannot be done. The amount of water added is very closely related to the porosity of the W / O type emulsion polymer. When the amount of water added increases, the porosity increases, and conversely, when the amount added decreases, the porosity decreases.

Then, the obtained W / O type emulsion is polymerized and cured. Polymerization temperature and time are 100 ℃ to avoid significant phase separation of W / O type emulsion and evaporation of water.
It is preferable that the time is 1 to 48 hours.

The polymer thus obtained is dried by a method such as hot air drying, internal heating drying, vacuum drying or freeze drying to evaporate water uniformly dispersed in the polymer to evaporate the inorganic substance of the present invention. A powder-containing porous polymer is obtained.

Furthermore, the inorganic powder-containing porous polymer of the present invention produced by the above-mentioned method can be fired by a usual method to obtain an inorganic porous material. That is, first, a polymer of a polymerizable unsaturated compound that is an organic substance in an inorganic powder-containing porous polymer, an emulsifier, etc. is removed by thermal decomposition or oxidative decomposition, while the silicate inorganic compound powder maintains a porous skeleton. After that, the silicate inorganic compound powder is fired or bonded to obtain an inorganic porous material. The inorganic powder-containing porous polymer used in the production of this inorganic porous material needs to contain 60% by weight or more of the inorganic powder with respect to the total amount of the inorganic powder, the polymerizable unsaturated compound and the emulsifier. If the content of the inorganic powder is less than 60% by weight, the amount of organic substances to be removed becomes too large, and cracks or blisters occur in the firing step, which is not preferable. Further, in the present invention, when a polyfunctional unsaturated compound having two or more double bonds is used as the polymerizable unsaturated compound in combination, the polymer has a crosslinked structure, and therefore the temperature rising rate during firing is high. Is preferable, and the amount of energy required for firing is small, which is economical.

[0025]

The organosilicon compound having a specific structure used in the present invention has the effect of hydrophobizing the surface of the silicate powder having hydrophilicity, and due to the effect, it has been difficult to form the silicate powder in the oil phase. It is considered that a W / O type emulsion in which a large amount of is mixed and dispersed can be stably produced. On the other hand, tetraalkyl (aryl) silanes which do not have any alkoxyl groups directly bonded to silicon atoms, which are outside the scope of the present invention, do not have any organic groups bonded to silicon atoms via carbon. Tetraalkoxysilanes, or even an organosilicon compound having one or more alkoxyl groups directly bonded to a silicon atom and one or more organic groups bonded to a silicon atom via carbon, the organic group However, methylalkoxysilanes having 2 or more carbon atoms have no or insufficient hydrophobizing effect on the surface of the silicate powder, so that a W / O type emulsion is not formed or is unstable even if formed. It requires a large amount of oil phase.

[0026]

EXAMPLES The present invention will be described in more detail below with reference to examples. The following raw materials were used. <Emulsifier> Solbitane sesquiolate (Kao Corporation, trade name: Rheodol AO-15, HLB = 3.7) <Organosilicon compound> (1) 3-methacryloxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd.)
(Product name: LS-3380) (2) Ethyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., Product name:
LS-890) (3) Phenyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., trade name: LS-2750) (4) Methyltriethoxysilane (Shin-Etsu Chemical Co., Ltd., trade name:
LS-1890).

[Measurement of Inorganic Porous Body] The apparent porosity and bulk specific gravity of the inorganic porous body were determined based on the following calculation formula (Equation 1).

[0028]

[Equation 1]

EXAMPLE 1 A solution of 100 parts by weight of cordierite and 1 part by weight of 3-methacryloxypropyltrimethoxysilane (LS-3380) in 1.1.1-trichloroethane (100 ml) was mixed by stirring for 5 minutes. 30 at 60 ° C.
It was heated for 1 minute, dried, and then heat-treated at 105 ° C. for 4 hours to obtain surface-treated cordierite.

Next, 100 parts by weight of the surface-treated cordierite, 36 parts by weight of styrene, 4 parts by weight of trimethylolpropane trimethacrylate (TMPT), and 10 parts by weight of sorbitan sesquioleate were placed in a polyethylene container and put in a propeller type. The mixture was stirred with a stirring blade to obtain a dispersed mixture. When 100 parts by weight of water in which 0.4 parts by weight of ammonium persulfate was dissolved was gradually added to this and further vigorously stirred, a stable W / O type emulsion was obtained.
Pour the obtained W / O type emulsion into a mold,
It was polymerized and cured at 24 ° C. for 24 hours, then demolded and dried at 60 ° C. to obtain the cordierite powder-containing porous polymer of the present invention. The obtained cordierite powder-containing porous polymer had appropriate strength and could be cut.

Example 2 A cordierite powder-containing porous polymer of the present invention was obtained in the same manner as in Example 1 except that the amounts of styrene, TMPT and emulsifier used as the polymerizable unsaturated compound were changed. The obtained cordierite powder-containing porous polymer had appropriate strength and could be cut.

Examples 3 to 6 As the silicate powder, glass powder, kibushi clay, sericite and kaolin were used.
An inorganic powder-containing porous polymer was produced in the same manner as in Example 1 except that the compounding amounts of the polymerizable unsaturated compound, the emulsifier, the polymerization initiator and the water were appropriately selected as shown in Table 1. All of the obtained inorganic powder-containing porous polymers had appropriate strength and could be cut.

Comparative Example 1 An attempt was made to prepare a W / O type emulsion in the same manner as in Example 1 except that cordierite that had not been surface-treated was used, but no W / O type emulsion was produced.

Comparative Example 2 Methyltriethoxysilane (LS) outside the scope of the present invention
-1890) except that W /
An attempt was made to prepare an O-type emulsion, but no W / O-type emulsion was produced.

[0035]

[Table 1]

Example 7 The cordierite powder-containing porous polymer obtained in Example 1 was heated in air at a heating rate of 50 ° C./hr and at a firing temperature of 13
It was fired at 00 ° C. to obtain a cordierite porous body.
No cracks or blisters were found in the obtained porous body. The apparent porosity and bulk specific gravity of the obtained cordierite porous body were 73.3% and 0.69, respectively.

Comparative Example 3 The cordierite powder-containing porous polymer obtained in Example 2 was calcined in the same manner as in Example 7, and the amount of the inorganic powder, the polymerizable unsaturated compound and the emulsifier was calculated based on the total amount. Since the amount of the inorganic powder was as small as 50% by weight, cracks were generated in the obtained porous body.

Example 8 The glass powder-containing porous polymer obtained in Example 3 was fired in air at a heating rate of 50 ° C./hr and a firing temperature of 770 ° C. to obtain a glass porous body. No cracks or blisters were found in the obtained glass porous body. The apparent porosity and bulk specific gravity of the obtained glass porous body were 58.
It was 3% and 1.08.

[0039]

INDUSTRIAL APPLICABILITY According to the present invention, a porous polymer containing a large amount of silicate powder using a W / O type emulsion can be manufactured. Therefore, if it is fired, it is possible to manufacture an inorganic porous body having fine pores without cracks or blisters. Such a porous polymer or an inorganic porous material is useful for building materials, sound absorbing materials, filters, various adsorbents, various carriers, etc. by making the most of its characteristics.

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Claims (3)

(57) [Claims] 1. An inorganic powder, a polymerizable unsaturated compound, an emulsifier,
In a method for producing an inorganic powder-containing porous polymer obtained by polymerizing and curing a W / O type emulsion comprising a polymerization initiator and water, water is removed, and the following chemical formula 1 is used as the inorganic powder.
A method for producing a porous polymer containing an inorganic powder, which comprises using a silicate powder surface-treated with an organosilicon compound represented by (Chemical Formula 1). [Chemical 1] 2. The method for producing a porous polymer containing an inorganic powder according to claim 1, wherein the silicate powder is at least one selected from glass, cordierite, clay, kaolin and mica. 3. The inorganic powder-containing porous polymer according to claim 1, which comprises 60% by weight or more of the inorganic powder with respect to the total amount of the inorganic powder, the polymerizable unsaturated compound and the emulsifier. And a method for producing an inorganic porous material.