JPH0446071A - Production of porous material - Google Patents

Abstract

PURPOSE:To obtain a water impermeable porous material with micropores of a uniform diameter in the surface by coating inorg. powder or granules wetted with a curable resin soln. with a gas impermeable sheet in a hermetically sealed molding tool, degassing the powder or granules under reduced pressure and curing the resin under pressure. CONSTITUTION:Inorg. powder or granules are mixed with a curable resin soln., wetted with the soln., coated with a gas impermeable sheet in a molding tool and degassed under reduced pressure. The resin is then cured while or after applying pressure with a roller. The powder or granules are bonded with the resin and a water impermeable porous material with micropores of a uniform diameter in the surface is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a porous material that is particularly suitable for use as a flooring material for wet areas.

(Prior Art) It is known to use a porous material in which inorganic powder and granules are bonded with a curable resin such as an unsaturated polyester resin as a flooring material for a place that gets wet with water such as a bathroom.

This type of porous material is generally produced by pressure-molding a mixture of inorganic powder and curable resin liquid such as unsaturated polyester resin using a room temperature press machine or a hot press machine. (For example, see Utility Model Application Publication No. 2-11937).

(Problem to be Solved by the Invention) However, in this way, the powder and granule obtained by mixing an inorganic powder and a curable resin liquid and making it wet with this resin liquid have a particle size change due to secondary aggregation in -S. The dispersion is increasing.

When such granular materials are pressure-molded using a press machine including an upper mold and a lower mold without using rollers, the large spaces existing between the granular materials cannot be filled satisfactorily.

As a result, the pore diameters of the resulting porous material become uneven,
It is not easy to adjust the pore diameter within a certain range, and it may not be possible to sufficiently prevent slipping or staining when wet with water.

The present invention solves these problems with conventional methods, and its purpose is to have a large number of fine pores with uniform diameters, and to ensure prevention of slipping and staining even when wet with water. An object of the present invention is to provide a method for manufacturing a porous material that can be carried out.

(Means for Solving the Problems) In the present invention, a method for producing a porous material according to claim 1 is characterized in that a curable resin liquid is mixed with an inorganic powder and granules are wetted with the resin liquid. Claim 2, characterized in that the body is covered with a gas-impermeable sheet in a mold, the air between the particles is degassed under reduced pressure, and then the resin is cured while or after being pressurized by a roller. The method for manufacturing porous materials is to mix inorganic powder and granules with a curable resin liquid, cover the powder and granules moistened with the resin liquid with a gas-impermeable sheet in a mold, and then After the air between them is degassed under reduced pressure, the resin is cured while being pressurized by a roller or after being pressurized through a sheet-like material that can be elastically or plastically deformed.

In the present invention, inorganic powders include inorganic powders such as quartz, kaolin, clay, silica sand, and crushed natural stone powder, natural mineral fibers, glass milled fibers, alumina short fibers,
Powders of inorganic short fibers such as potassium titanate short fibers, carbon short fibers, and voice car are used.

The maximum particle size of the inorganic powder is preferably 1000 μm or less.

In addition, in the case of powder of inorganic short fibers, it is desirable that the average thickness of the fibers is 300 μm or less. When the maximum particle size exceeds 1000 μm, the pores formed on the surface of the resulting porous material become large, and dirt and the like easily enter the pores and become dirty.

In addition, as the curable resin, unsaturated polyester resin,
Organic peroxide, diallyl phthalate resin, epoxy resin, phenol resin, urethane resin 1, vinyl ester resin, epoxy acrylate resin, acrylic resin, etc.
Room-temperature curable or thermosetting resins containing conventional curing agents and catalysts such as amines and acid anhydrides are used, and if necessary, curing accelerators are added.

The curable resin is used in liquid form, and its viscosity is desirably adjusted to 100 voids or less at room temperature depending on the polymerizable monomer, the degree of polymerization of the resin, etc. If the viscosity is higher than 100 voids at room temperature, secondary aggregation of the powder particles will increase, the resulting porous material will have large and non-uniform pore diameters, and dirt will easily enter the pores and become dirty.

The method of mixing the curable resin liquid with the inorganic powder is to add a small amount of the curable resin liquid to the inorganic powder and stir it, or to spray a small amount of the curable resin liquid onto the inorganic powder. Generally, the method of impregnating the In this case, the two may be mixed and then placed in the mold, or the two may be mixed in the mold.

When mixing the curable resin liquid with the inorganic powder, the mixing amount is such that the inorganic powder is moistened with the resin liquid and maintains the powder state. It is determined by taking into consideration factors such as the particle size, type and viscosity of the curable resin liquid, and pressure molding conditions.

Generally, the bulk volume ratio is 1 part of inorganic powder to 0 part of curable resin liquid.
．． It is prepared in the range of 0.05 to 0.5. At this time, it may be colored by mixing various pigments. In this way, a powder or granule in which the inorganic powder or granule is moistened with the curable resin liquid is produced.

This granular material is covered with a gas-impermeable sheet in a desired mold such as a peelable plate-shaped mold or a flat box-shaped mold. As the gas-impermeable sheet, a plastic sheet made of polyethylene, polypropylene, polyester, nylon, etc. is used.

The edge of this gas-impermeable sheet is airtightly sealed with a sealant, a sealing frame, or the like to the upper or side surface of the edge of the mold containing the powder or granules. Then, air inside the mold is sucked by a vacuum pump through one or more decompression holes formed in a part of the mold, thereby depressurizing and deaerating the air between the particles. The internal pressure is preferably 400 mHg or less and higher than the vapor pressure of monomers, etc.

The mold containing the powder and granules that has been degassed under reduced pressure is transferred to a roll press machine and heated at a temperature of, for example, room temperature to 150"C, 1 to 15"C.
Pressure is applied by a roller presser at a pressure of 0 kg/c4. As a roller press machine, a device is generally used that consists of one or more sets of rotatably driven press rolls arranged one above the other, with the upper roll being able to be heated and being able to be pressed against the lower roll by a hydraulic cylinder. However, in some cases, a press machine consisting of an upper roll and a lower die may be used.

The mold containing the granular material is transferred between the upper and lower rolls of the roller press machine as described above, and is pressurized by a hydraulic cylinder at a constant pressure and at a constant temperature. The curable resin may be cured while being pressed by a roller, or may be cured after being pressurized by a roller, for example, at room temperature or by heating to a temperature of 150° C. or less.

During pressure molding, a sheet-like material that can be elastically or plastically deformed is placed on top of the gas-impermeable sheet covering the powder and granules, and pressure is applied by rollers through this sheet-like material. This is effective in making the pore diameters more uniform. Examples of sheets that can be elastically deformed include rubber sheets, plastic foam sheets, non-woven fabrics, felt, etc. Examples of sheets that can be plastically deformed include plastic sheets filled with highly viscous fluid and pastes such as clay paste. A shaped sheet or the like is used.

Note that gas-impermeable sheets and sheet-like materials that can be elastically or plastically deformed are usually peeled off after pressure forming, but if they are adhered to the resulting porous material, these sheets There is no need to peel away these sheet materials after pressing, as the material becomes the back side of the porous material.

In this way, the curable resin liquid is cured at room temperature or by heating, and as a result, the inorganic powder and granules are bonded by the curable resin, and a large number of fine pores with uniform diameters are formed on the surface (the surface in contact with the mold surface). A porous material with open pores is obtained.

(Function) In the method of the present invention, a wet powder formed by mixing a curable resin liquid with an inorganic powder is covered with a gas-impermeable sheet in a mold to prevent air between the powder and granules. After depressurizing and degassing,
When pressure is applied by the roller, the powder and granules are pressed one after another by the rotation of the roller, and the powder and granules move well not only vertically but also horizontally. the result,
The large spaces between the powder and granules are filled well, and a porous material with well-uniformed pore diameters is obtained.

Moreover, when the air between the powder particles is degassed under reduced pressure, it is more effective because it is prevented from restoring and enlarging the pores when the pressure is released to normal pressure after pressurization.

Moreover, since almost no air (oxygen) exists between the powder particles, the curing reaction is not inhibited by oxygen and the curing proceeds rapidly.

In addition, when the powder and granules are pressed by rollers through a sheet-like material that can be elastically or plastically deformed, the pressing force applied to the powder and granules is made uniform, and a porous material with more uniform pore diameters can be obtained. It will be done.

(Example) Examples and comparative examples of the present invention are shown below.

1 star lulumina fiber short fiber (300 mesh bath) 2
500 parts by weight and 2000 parts by weight of a thermosetting epoxy acrylate resin (12 voids) containing 1.5 weight percent of hardening side (Perhexa 3 gates; manufactured by Nippon Oil & Fats Co., Ltd.), the former being 1 in bulk volume ratio. The latter was mixed uniformly at a ratio of 0.25 to the latter to produce a wet powder.

Spread this powder uniformly in a flat box-shaped mold, cover it with a polyester sheet (approximately 1OOp layer), and seal the edges of the sheet airtightly with a silicone sealant at the upper edge of the mold. The pressure inside the mold was reduced to 100 mh (gauge) using a vacuum pump through the decompression hole formed in a part of the mold, and the cholera temperature was 100°C. The pressure of the hydraulic cylinder was reduced to 40 mh.
After passing through a roller pressure machine set at kg / cnJ, it is heated to 100°C to harden the resin, the polyester sheet is removed and the mold is demolded, and the inorganic powder is bonded with a hardening resin and the pore size is formed on the surface. A porous material with a thickness of 6 mm consisting of a water-impermeable porous body with a uniform set of minute pores was produced.

Regarding this porous material, the slip resistance, stain resistance, pore diameter, and pore volume were measured and evaluated using the following methods. The results are shown in Table 1.

(1) Slip resistance was determined by layering a 30mm x 50mm piece of synthetic leather on the surface of a porous material that was wet with water, and then adding 2kg of synthetic leather to the surface.
The friction coefficient was measured by the slope method, and the friction coefficient of 0.8 or more was expressed as 0, less than 0.8 to 0.6 was expressed as Δ, and less than 0.6 was expressed as x.

(2) Stain resistance is determined by talc powder (particle size of 10 μl or less)
is dispersed in water at a ratio of 0.2 g/cc, and 50 cc of this dispersion is sprinkled on the surface of a 100 mm x 100 mm porous material. If the talc powder remains on the surface and can be washed off later, mark as ○. , The case where the talc powder caused clogging in the pores on the surface was indicated by ×.

(3) The diameter of the pores was measured using a mercury porosimeter, and the case where 95% or more of the pores had a pore diameter of 20 μm or less was expressed as an x, and the case where the percentage of pores with a pore diameter of 20 μm or less was less than 95% was indicated by an “×”.

(4) The pore volume was measured with a mercury porosimeter, and 0.05 cc/g or more was expressed as Olo, and less than 0.05 cc/g was expressed as x.

Thermosetting epoxy resin (4 voids) (TETRAD-X + Mitsubishi Gas Chemical Co., Ltd.) made by uniformly spreading mica (100 mesh bath) in a flat box-shaped mold and blending an equivalent amount of a hardening agent (diaminodiphenylmethane) with it. ) was sprayed and impregnated at a bulk volume ratio of 1 to 0.15 of the latter.

Cover the top with a polyester sheet, seal the edges with the upper edge of the mold, depressurize the inside of the mold to 300 m) Ig (gauge), and reduce the pressure of the hydraulic cylinder to 25 m).
After shaping through a roller pressure machine set at kg/cnl, the resin is cured by heating to 120-180"C, the polyester sheet is removed and the mold is demolded, and the inorganic powder becomes a curable resin. A porous material with a thickness of 6 mm consisting of a water-impermeable porous body with fine pores of uniform pore size formed on the surface was produced.

Regarding this porous material, the slip resistance, stain resistance, pore diameter, and pore volume were measured and evaluated using the following methods. The results are shown in Table 1.

A styrene solution of thermosetting unsaturated polyester resin containing 2% by weight of a curing agent (penduyl baroxide) was mixed with quartz powder (200 mesh baths) and a bulk volume ratio of 1 vol. The latter was mixed uniformly at a ratio of 0.25 to the latter to produce a wet powder.

Spread this powder uniformly in a flat box-shaped mold, cover it with a nylon sheet, seal the edges with the upper edge of the mold, and adjust the inside of the mold to 200 mmHg (gauge).
The pressure in the hydraulic cylinder is reduced to 50k.
After shaping by passing through a roller press machine set at g/cIll, heat to 80"C to harden the resin and demold, the inorganic powder is bonded with a hardening resin and the surface has uniform pore sizes. 6-thickness made of a water-impermeable porous material with minute pores.
A porous material was produced.

Regarding this porous material, the slip resistance, stain resistance, pore diameter, and pore volume were measured and evaluated using the following methods. The results are shown in Table 1.

l1 decay 1 carbon milled fiber (average fiber length 300μm)
and a thermosetting unsaturated polyester resin (
12 poise), with a bulk volume ratio of 1 to 0.1 for the latter.
A wet powder was prepared by uniformly mixing the ingredients at a ratio of 5:5 to 5:5.

Spread this powder uniformly in a flat box-shaped mold, cover it with a nylon sheet, seal the edges with the upper edge of the mold, and place wool felt (10III thick) on top.
ll), the inside of the mold was depressurized and degassed to 100mHg (gauge), passed through a roller pressure machine heated to 80°C, pressurized with a hydraulic cylinder pressure of 40kg/c+fl, and then heated to 80°C. The resin is cured by heating, the nylon sheet and wool felt are removed and demolded, and the inorganic powder is bonded with a hardening resin to form an impermeable surface with fine pores of uniform diameter. A porous material having a thickness of 6+m++ was produced.

Regarding this porous material, the slip resistance, stain resistance, pore diameter, and pore volume were measured and evaluated using the following methods. The results are shown in Table 1.

Marble crushed powder (180 mesh bath) and room temperature curable epoxy resin (15 poise) (Nisdyne 400: manufactured by Block Chemical Co., Ltd.) were uniformly mixed in a bulk volume ratio of 1 for the former to 0.15 for the latter. They were mixed to form a wet powder.

Spread this powder uniformly in a flat box-shaped mold, cover it with a polyester sheet, seal the edges with the upper edge of the mold, and place a nitrile rubber sheet (thickness 7
an) and 100 wflg (gauge) inside the mold.
Degassed under reduced pressure and passed through a roller press machine at room temperature 2
The resin is cured at room temperature by pressurizing with a hydraulic cylinder pressure of 0 kg/c1il, the polyester sheet and nitrile rubber sheet are removed and demolded, the inorganic powder is bonded with a hardening resin, and the surface is made of fine particles with uniform pore sizes. A porous material having a thickness of 6 mm and consisting of a water-impermeable porous body with pores opened therein was produced.

Regarding this porous material, the slip resistance, stain resistance, pore diameter, and pore volume were measured and evaluated using the following methods. The results are shown in Table 1.

Spread white mica powder (200 mesh baths) evenly in a flat box-shaped mold, and add a hardening agent (Vercure 0:
A styrene solution (1 void) of a thermosetting unsaturated polyester resin containing 2% by weight (manufactured by NOF Corporation) was sprayed and impregnated at a bulk volume ratio of 1 to 0.25 of the latter.

Cover it with a polyester sheet, seal its edges with the top edge of the mold, and apply clay paste on top of it in the form of a sheet (
5mm), and the inside of the mold was heated to 100mmJlg (
Gauge), the resin is degassed under reduced pressure, passed through a roller pressure machine with a hydraulic cylinder pressure set to 50 kg/cd, and then heated to 80°C to harden the resin.
Remove the polyester sheet and clay paste and demold,
A 6-thick, water-impermeable porous body made of inorganic powder bound with a curable resin and with fine pores of uniform pore size on its surface.
A porous material was produced.

Regarding this porous material, the slip resistance, stain resistance, pore diameter, and pore volume were measured and evaluated using the following methods. The results are shown in Table 1.

The process was carried out in the same manner as in Example 1 except that the inside of the clay molding mold was not degassed under reduced pressure and the pressure applied by the roller press was replaced by pressurization by a press.

Comparison Example 2 was carried out in the same manner as in Example 2, except that the inside of the mold was not depressurized and degassed, and the pressure applied by the roller pressure machine was replaced by the pressure applied by a press machine.

Example 3 was carried out in the same manner as in Example 3 except that the inside of the main mold was not degassed under reduced pressure and the pressure applied by the roller press was replaced by pressurization by a press.

(Margins below) Table 1 (Effects of the Invention) As mentioned above, according to the production method of the present invention, the granular material is mixed with an inorganic powder material and a curable resin liquid, and the powder material is moistened with this resin. After the air between the particles is degassed under reduced pressure by being covered with a gas-impermeable sheet in the mold, the resin is cured by pressure applied by rollers, so the inorganic particles are bonded with the curable resin. A water-impermeable porous material with fine pores of uniform pore size on the surface is obtained.

When the pore diameters on the surface are uniform in this way, it becomes easy to set the pore diameter within a certain range, and it is possible to reliably prevent slipping when wet with water and prevent staining due to clogging.

Moreover, the curing of the curable resin becomes faster, improving productivity. The method according to the invention has these advantages.

Therefore, the porous material obtained by the method of the present invention is
It can be suitably used for flooring, counters, tables, moisture absorbing/releasing wall materials, soundproof building materials, etc. that are expected to have an anti-slip effect, such as in bathrooms, toilets, galleys, entrances, balconies, shower rooms, poolsides, and sidewalks.

Claims (1)

[Claims] 1. Mix a curable resin liquid with an inorganic powder, cover the powder moistened with the resin liquid with a gas-impermeable sheet in a mold, and A method for producing a porous material, which comprises degassing the air under reduced pressure, and then curing the resin while or after applying pressure with a roller. 2. Mix a curable resin liquid with an inorganic powder, cover the powder moistened with the resin liquid with a gas-impermeable sheet in a mold, and degas the air between the powder and granules under reduced pressure. After that, the resin is cured while being pressed by a roller through a sheet-like material capable of elastic deformation or plastic deformation, or after being pressurized.