JPS5962324A - Filter medium and its manufacture - Google Patents

Abstract

PURPOSE:To provide a filter medium suitable for a reverse osmosis and an ultrafiltration, by building up porous glass layers having the fine holes to form a layer having the prescribed thickness on the surface of a porous ceramic layer, in forming a filter medium. CONSTITUTION:A porous ceramic is prepared; which consists essentially of a sintered body having alumina, iron oxide, and silica, etc. and is formed into a plate or tubular body having 1-10mm. thickness after regulating the surface area of its hole, whose diameter is ordinarily 0.5-0.5mu, to <=0.1mu. Next, porous glass layers having 5-1,000Angstrom hole diameters are built up to form 0.1-100mu thickness layer on the surface of a carrier body consisting of said porous ceramics, thereby constituting an object filter medium. This filter medium can be formed into an optional form such as a plate, tube, and cylinder; and whose porous ceramic layer and porous glass layer are joined together in a chemically solid state. Accordingly, the filter medium is used for over a long period of time without causing a separation of the layers, and is excellent in pressure resistance, heat resistance, chemical resistance, and mechanical strength, and is suitable for the separation of various kinds of fluids especially for a reverse osmosis and an ultrafiltration.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel filter material suitable for use in reverse osmosis and ultrafiltration, and a method for producing the same.

More specifically, the present invention relates to a filter material having a structure in which a porous glass layer is laminated on the surface of a porous ceramic layer and is suitable for separating various fluids, and a method for efficiently manufacturing the same. .

So far, as filter media for reverse osmosis and ultrafiltration applications, inorganic filter media such as clay plates, and organic filter media such as cellulose acetate, polyacrylonitrile, polybenzimidazole, and polyamide have been known. However, since it is difficult to form inorganic filter media into a thin film with micropores on the order of angstroms, their applications are inevitably limited, and organic filter media are heat resistant,
In addition to being poor in durability, it has the disadvantages that microorganisms adhere to it and require a great deal of effort to remove it.

On the other hand, ZrCl2. Zr0c12゜Th
014. Fe015. Pb0Hc12. UO20
Inorganic compounds such as HO1, AlCl2, humic acid,
So-called dynamic membranes coated with colloidal membranes of organic polymer compounds such as polyvinylpyridine, polyglutamic acid, polyacrylic acid, polymethacrylic acid, and polystyrene sulfonic acid are used for desalination of cancer water and purification of industrial wastewater. It is known that it is suitable as a filtration agent. However, this dynamic membrane cannot be used for gas separation (/i) because it forms a membrane in an aqueous solution, and the pH
Since the stability range is 4 to 10, it tends to have the disadvantage that it cannot be used under strongly acidic or strongly alkaline conditions9, so it cannot necessarily be said to be a satisfactory filter medium.

The present inventors aim to overcome the drawbacks of such conventional filter media and develop a filter media that can be stably used in any pH range and temperature range and has excellent filtration performance. As a result of extensive research, we discovered that this goal could be achieved by forming a porous glass layer with a specific pore size and thickness on the surface of a porous ceramic layer. Based on this knowledge, we The present invention has been accomplished.

That is, in the present invention, on the surface of the porous ceramic layer,
The present invention provides a filter material made of porous glass layers laminated to an arbitrary thickness of 1 to 100 μm, in which the pore diameter of 5 to 1000× can be arbitrarily controlled.

The porous ceramic used as a support in the filter medium of the present invention can be arbitrarily selected from porous ceramics used as supports of conventional dynamic membranes. Examples of such materials include sintered bodies containing alumina, iron oxide, titanium oxide, Magui/lamb oxide, silica, and the like as main components. Typically, this support has a surface area of 0.2 to 0.5 microns with a pore size of 0.2 to 0.5 microns.
The filter material of the present invention is used in the form of a plate or tube with a thickness of 1 to 10 mm after controlling 1 μ or less (・ζ). The glass layer i has a laminated structure with a thickness of 0.1 to 100μ.This porous glass layer has, for example, the general formula %formula %) (in which at least one is an alkyl group and the remainder is an alkyl group). is a hydrogen atom) It is obtained by heat-treating a porous gel produced by hydrolyzing a silicon alkoxide represented by the following with an acid. It is important that the pore size of this porous glass layer is in the range of 5 to 1oooX; if it is less than 5X, the permeation pressure will be extremely high and smooth filtration will not take place, and the pore size will be larger than 1oooX. Then, separation between the fluids becomes impossible.

On the other hand, the thickness of this porous glass layer is 0.1 to 100μ
If it is less than 0.1μ, the performance of reverse osmosis and ultrafiltration will be significantly reduced, and if it exceeds 100μ, the permeation pressure will increase and it will become unusable. .

To manufacture the filter medium of the present invention, first, a water bath solution is prepared by adding a mixture of a thickener, water, alcohol, and acid to, for example, /licon alkoxide. In this case, it is necessary to appropriately select the time for adding the mixture, otherwise a glass film will not be formed. A predetermined porous ceramic is immersed in the aqueous solution obtained in this way, or applied to the surface to a thickness of 0.2 to 200 μm, dried at room temperature, and then heated to 400 to 800 ° C. This temperature is maintained until the water produced by the dehydration condensation reaction is removed.

The heat temperature at this time may be increased if the pores of the gel are large, but if the pores of the gel are small, care must be taken because if the pores are made high, the gel will become non-porous.

In this way, a porous layer 92 of silica glass tightly bonded to the surface of the porous ceramic layer can be formed.

As this porous glass layer, in addition to silica glass, materials to which alumina or titania is added can also be used.

The filter medium of the present invention can be made into any shape such as a plate, tube, or cylinder, and since the porous ceramic layer and the porous glass layer are chemically strongly bonded, it can be used for a long period of time. However, there is no risk of this peeling off even if you use it.Since it is composed only of inorganic substances, it has excellent pressure resistance, heat resistance, chemical resistance, and mechanical strength, and is especially suitable for separating various fluids. It is suitable for permeation and ultrafiltration applications.Furthermore, unlike the Tainamisoku membrane, this membrane can also be used for gas separation, and has the advantage that it can be easily cleaned even if it becomes contaminated. There is.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Solicon tetraethoxide 1002, hydrochloric acid 12, water 95
7. A mixture of 150 g of ethanol and a thickener added,
Add it gradually while stirring well and let it react for about 60 minutes. In this way, a solution to be applied to porous ceramics was prepared.

The porous ceramic to be coated was one whose surface was specially processed to have a pore diameter of 0.01 μm or less in order to prevent absorption of the solution into the pores.

The surface of the porous ceramic (cylindrical shape with a diameter of 5 μm) was immersed in the solution prepared as described above.
After drying at room temperature for 10 minutes,
Heat at ℃ for 20 minutes.

In this way, it was possible to produce a filter medium in which a layer of porous silica glass with a thickness of approximately 1 μm having a pore diameter of approximately 50× was firmly bonded to porous ceramics.

Note that porous silica glass membranes with different pore sizes were obtained by varying the amount of mixed solution prepared or by changing the heating temperature and time.

The thickness of the porous silica glass film can be determined by coating the porous ceramic by dipping it into a solution two or more times, or
It could be freely controlled by increasing the amount of thickener added to the solution.

Patent applicant Tokyo Denki Kagaku Kogyo Co., Ltd. Agent A
Form Clear procedural amendment December 1980, 11th day 1・It l'l's large and small Showa] Ro 1957 l Permission Application No. 171191 2 Issued in November 1゜Filter media and its manufacturing method 31 mountains 11 1 ν side with 1 state 'Patent applicant f1+su 'Higashigoni Miyako [Po-ku Japanese Overseas-Chome 13-1 Representative Nagisa Motono Fukujibe 1st representative 〒104 Sono, Miyako "Ya Building 5, 6-4-55 S Ajin, Chuo-ku] Minna 6, h1i+IL:"'"'l1lllt
7. , l 51'"Hcr+h (l
i'''11' j・, 5 71111 stop iJ Iko Specification J1 l Retention Seishui range I
Column for (-1, t': 10 Claim 1 Surface of porous ceramic layer f7. 5 to 1000
A filter material comprising porous glass layers laminated to a thickness of 0 to 100 μm.

2 Porous: A porous gel obtained by decomposing 7-licon alkoxy/d with hydrohydrolysis is applied to the surface of Niraminox, and
A method for producing a filter medium, characterized by heat treatment at a temperature of 0.-800°C.

Claims (1)

[Scope of Claims] 1. A filter material comprising a porous glass layer having a pore diameter of 5 to 1000 μm laminated to a thickness of 0.1 to 100 μm on the surface of a porous ceramic layer. 2 Apply porous gel obtained by hydrolyzing silicone alcoquid to the surface of porous ceramics, and
A method for producing a filter medium, comprising heat treatment at a temperature of 800°C.