JPH01212284A - Production of porous refractory solid - Google Patents

Abstract

PURPOSE:To obtain the title solid having large porosity and excellent air permeability, pressure resistant strength and bending strength by laminating plural org. plates having through-holes of a prescribed shape in such a manner that the through-holes thereof communicate with each other, then injecting a slurry contg. metal powder and/or refractory raw material powder into the through- hole parts and subjecting the laminated plates to a solidifying treatment and sintering. CONSTITUTION:The plural organic plates 1 such as foamed polystyrene plates, foamed urethane foam plates or foamed PE plates having the through-holes 2 of the prescribed shape are laminated in such a manner that the through-holes 2 of the respective org. plates 1 communicate with each other. The slurry prepd. by mixing the metal powder of Al, Si, etc., and/or the refractory powder of CaO, Al2O3, SiO2, MgO, SiO, Si3N4, etc., having the grain size of <=1/10 the max. diameter in the intercommunicating parts of the through-holes 2 with water or nonaq. soln., etc., in such a manner as to have 10-2,000p viscosity is then injected into the through-hole 2 parts communicating with each other and is solidified; thereafter, the solidified solid is sintered and the org. plates 1 are annihilated simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a porous refractory solid used as a solid heat transfer converter, a heat radiator, a catalyst carrier, a filter material, or the like.

[Prior Art/Problems] Recently, porous solids having air permeability have been attracting attention as solid heat transfer converters, heat radiators, catalyst carriers, or transient materials.

As a method for manufacturing such porous solids, for example, flexible polyurethane foam is treated to remove the cell membrane to produce Scotto foam having a regular dodecahedral product structure, and this Scotto foam is impregnated with ceramic slurry to remove the excess slurry. There is a method of vaporizing and removing the Scotto foam and sintering the ceramic by removing and drying the ceramic.

The porous solid (ceramic foam) obtained by this method is lightweight, has a large porosity, has a columnar structure, and has various advantages such as low flow resistance. However, because the porous solid has a columnar structure, it has poor pressure resistance or bending strength, and its flow resistance is too low, so when used as a solid heat transfer converter, sufficient heat storage characteristics cannot be obtained. There were drawbacks such as:

On the other hand, a particle sintered porous body obtained by sintering refractory particles has also been proposed as a method for producing a porous solid having air permeability.

In this method, a porous body with uniform pores produced by sintering refractory grains with strictly controlled grain sizes can be obtained.
However, the porosity is about 30 to 50%, and there is a problem that a porosity of 50% or more cannot be obtained.

In addition, the present inventors previously proposed a method for producing a porous material obtained by eliminating the organic method in Japanese Patent Application Laid-open No. 60-251182, but it was insufficient in terms of strength and pore morphology, and Improvements are desired.

Therefore, an object of the present invention is to provide a method for producing a porous refractory solid having a high porosity, air permeability, and high bending strength and compressive strength.

[Means for Solving the Problems] That is, the present invention stacks a predetermined number of organic plates having through holes of a predetermined shape so that the through holes of each organic plate communicate with each other,
Injecting a slurry containing metal powder, refractory raw material powder, or both and a solution into the mutually communicating through holes,
The present invention relates to a method for producing a porous refractory solid having air permeability, which comprises erasing the organic plate during or after the solidification treatment of the slurry-impregnated organic plate laminate.

[Function] The method of the present invention is shown in attached FIG. 1a and FIG.
This will be explained using FIG. b, FIG. 2a, and FIG. 2S.

In the method of the present invention, as shown in FIGS.
) in such a way that the through holes (2) in the organic plate (1) communicate with each other.
), and inject slurry into the through hole (2),
A porous refractory solid having ventilation holes as shown in FIGS. 2a and 2s is produced by removing the organic plate during or after solidifying the injected slurry.

The organic board used in the present invention includes a styrofoam board,
Examples include foamed urethane foam boards, polyethylene boards, wood boards, paper boards, carbon boards, etc., but from the viewpoint of cost and amount of gas generated, it is preferable to use foamed polystyrene boards, foamed urethane foam boards, and foamed polyethylene boards. Less is preferable.

The arrangement of the through holes in the organic board must be such that when M layers of organic boards are arranged as shown in Figure 1a and Figure 1S, the through holes in each organic board can communicate with each other. If the through-holes of each organic plate do not communicate with each other when the organic plates are stacked, the porous refractory solid obtained by erasing the organic plates will not be integrated and the desired purpose will not be achieved. I can't.

Although circular through-holes are shown in FIGS. 1a, 1b, 2a, and 2, the shape and size of the through-holes provided in the organic board are not particularly limited. It should be understood that the shape and size can be any shape and size depending on the purpose and use.

Metal powders used in the present invention include AI, Si, etc., which exhibit refractory properties through oxidation, carbonization, and nitridation, and refractory raw material powders include calcia, alumina, silica,
magnesia, silicon carbide, silicon nitride, alumina cement,
Those used for ordinary refractories such as ρ-alumina and Portland cement can be used, but their particle size must be 1710 or less of the maximum diameter of the interconnecting part of the through hole, and 1/10 If it exceeds 100 ml, it becomes difficult to inject the slurry into the through-hole.

Moreover, an inorganic binder can be added to the slurry as needed.

Water, non-aqueous solutions, etc. can be used as the solution for the slurry in the method of the present invention, but if a solution that dissolves organic plates is used, the organic plates will dissolve into the slurry when the slurry is injected. This is not preferable because the organic plate and the through holes cannot maintain their desired shapes.

The viscosity of the slurry is preferably in the range of 10 to 2000 boids; if it exceeds 2000 boids, it will be difficult to pour the slurry, and if the viscosity is 10 poise, it will be difficult to separate the solution and powder, i.e. solid-liquid. Separation phenomenon occurs and it becomes difficult to obtain slurry with uniform concentration.

In order to obtain the above-mentioned viscosity, the weight ratio of metal powder, refractory raw material powder, or both of them and the solution should be 10=3 to 1:10.
It needs to be within the range.

When the slurry is self-hardening at room temperature, the organic board is removed by immersing it in a solvent that can dissolve the organic board after hardening, and then firing to sinter the porous refractory solid with air permeability. can be done. If the slurry is not self-hardening, a porous solid can be obtained by simultaneously eliminating organic particles and sintering.

In one embodiment of the method of the present invention described in the attached FIGS. 1a, 1b, 2a and 2s, through-holes (2
) has been described, but it should be understood that the number of organic plates stacked can be any desired number.

[Example] - Three 51-thick styrofoam plates each having a through hole with a diameter of 101 mm are arranged so that the positions of the through holes are shifted and the through holes communicate with each other as shown in Figure 1a and Figure 1. Laminated.

Next, 60 parts by weight of alumina with a particle size of 0.3+ui or less, 5 parts by weight of alumina cement, and 3 parts by weight of water were added to the mutually communicating through holes.
Impregnating the voids of the styrofoam plate laminate with a slurry of 5 parts by weight, curing at room temperature, and then immersing it in an ethyl acetate solution,
The organic plate was dissolved. The properties of the obtained porous refractory solid with vents are listed in Table 1 together with the conventional product.

1) Layer three polyethylene plates having slit-like through holes as shown in Figure 3a, changing the direction of the through holes, and pour a slurry made of metal silicon and water into the through holes of the polyethylene plates. After injecting and drying, firing was performed at a temperature of 1400° C. in a nitrogen atmosphere to produce a silicon nitride porous refractory solid having ventilation holes. The structure of the porous refractory solid obtained is shown in Figure 3, and the properties are shown in Table 1.

After vibrating and filling the impregnated container with single-diameter expanded polystyrene beads with a diameter of 5 mm, a punching plate was inserted from above at 2 mm.
g/c++2, and in this state apply particles with a particle size of 0.
A slurry consisting of 60 parts by weight of alumina of 31 or less, 5 parts by weight of alumina cement, and 35 parts by weight of water is impregnated into the voids of the foamed polystyrene bead aggregate in the impregnating container, and after hardening at room temperature, it is immersed in an ethyl acetate solution, and an organic The ball was melted away.

The properties of the porous refractory solid obtained are listed in Table 1.

After applying self-hardening epoxy resin to the surface of the foamed urethane beads while mixing them at a weight ratio of 60:40, the foamed urethane beads with a diameter of 10III and one diameter of 11" were filled into a paper impregnated container by vibration. Next, a slurry made of metal silicon and water is impregnated into the voids of the foamed urethane bead aggregate in the container, and after drying, the temperature is 1400°C in a nitrogen atmosphere.
A porous refractory solid made of silicon nitride was produced. The properties of the porous refractory solid obtained are shown in Table 1.

[Effects of the Invention] According to the present invention, a porous refractory solid that not only has excellent compressive strength and bending strength and can obtain turbulent flow, but also has various air permeability by selecting metal powder and refractory raw material powder. is obtained.

[Brief explanation of the drawing]

FIG. 1a is a three-dimensional view showing one embodiment of the organic plate laminate, FIG. 1 is a cross-sectional view of FIG. 1a, and FIG. 3 is a three-dimensional view of a porous refractory solid having ventilation holes obtained using a laminate, FIG. 2 is a cross-sectional view of FIG. 2a, and FIG. It is a three-dimensional view of a plate laminate, and Figure 3 is a diagram showing the structure of the porous refractory solid having ventilation holes obtained in Example 2.・Through hole. Patent applicant: Shinagawa Shirorenga Co., Ltd. (0) Figure 2 Figure 3

Claims (1)

[Claims] A predetermined number of organic plates having through-holes of a predetermined shape are stacked so that the through-holes of each organic plate communicate with each other, and metal powder or refractory raw material powder or both and a solution are contained in the mutually communicating through-holes. A method for producing a porous fire-resistant solid having air permeability, the method comprising: injecting a slurry into the slurry, and erasing the organic plate during or after solidification of the slurry-impregnated organic plate laminate.