JPH07505331A - Deposition method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Deposition method FIELD OF THE INVENTION This invention relates to deposition methods useful in membrane production.

Zeolites and related crystalline materials have the ability to perform separations and act as catalysts. is well known. Membranes are well known for separation applications, and membranes containing zeolites are also known. It is. These membranes come in many different types.

CA 1235684 discloses a filter for material separation, which uses porous gas based on a substrate made of glass and zeolite formed directly on this porous glass. The zeolite-based thin film has a thickness of 1 μm to 500 μm. Ru. This filter uses, for example, borosilicate glass with sodium hydroxide and odor. Suspended in an aqueous solution of tetrapropylammonium chloride and placed in an autoclave. Created by heating.

JP-A-63291809 discloses a thin film of zeolite on a porous alumina support. Discloses a membrane consisting of:

EP-A-180200 describes a porous support impregnated with fine particles of zeolite. It describes a membrane consisting of: This membrane can be, for example, an ultrafiltration membrane or a porous glass membrane. alkali of ultrafine (e.g. less than 75 Angstroms in diameter) zeolite particles. It is created by infiltrating it with a liquid solution. These particles become lodged within the pores of the support. .

EP-A-180200 discloses that zeolite synthetic gel is passed through a microfilter. describes a method for producing a zeolite membrane that is deposited as a thin film on the surface of a support. There is.

DE-A-3827049 describes a layer of zeolite crystals on a porous support. discloses a zeolite membrane. When creating this membrane, the porous support was The nucleus is activated by immersion in an alumina-containing solution for a period of time and then evaporation of the solvent. a surface is provided on the support.

European Patent Application No. 91309239 (EP-A, -481) by the applicant No. 660) (the disclosure of which is incorporated herein by reference) is a porous support. Describes a method for producing a membrane comprising a thin film of xeo-type material on the pores of This method involves crystallizing at least one surface of a porous support to form a crystalline jelly. Immersion in a synthetic gel that can produce O-type substances; Crystallizing the mold material on the support; removing the support from the mixture; one or more times until the zeo-type material crystallizes directly from the support. The process consists of obtaining a membrane directly bonded to the support. Additionally, porous supports Novel membranes consisting of more supported crystals of zeo-type materials have also been described, The quality crystal growth is substantially continuous throughout the pores of the support and the zeo-type material is supported. It is characterized by being directly crystallized from the body and directly bonded to the support.

European Patent Application No. 91309237 (EP-A-4816) by the applicant No. 58) (the disclosure of which is hereby cited for reference) describes zeo-type materials. When depositing a synthetic gel onto a porous support, the support has a defined surface coverage. Its use has been shown to increase the growth of zeo-type materials during the initial soaking and crystallization steps It shows.

They also describe a method for depositing zeo-type materials onto porous supports, which can be used in many ways. crystallizing at least one surface of the porous support to produce a crystalline zeo-type material; The zeo-type material is crystallized on the support by immersing it in a grown gel and inducing crystallization of the gel. The surface of the support is coated with nitrogen as a metal and/or oxide. It is characterized by having a surface layer of cobalt, cobalt or molybdenum.

This time, the membrane manufacturing method can be improved by specifically treating the membrane support made of zeo-type material. Shiuroko was tracked down.

The invention therefore provides the following steps: (i) at least one surface of a porous support; silicic acid under conditions such that the silicic acid oligomer directly binds to the surface of the support. (ii) the oligomers are brought into contact with a solution or suspension containing the raw materials; Separating the combined support and the solution or suspension containing the silicic acid raw material; ( iii) a synthetic gel capable of crystallizing the surface of the support to produce a crystalline zeo-type material; contact to induce crystallization of the gel to crystallize the zeo-type material on the surface. A method for depositing a zeo-type material onto a porous support is provided.

Suitable solutions or suspensions containing silicic acid raw materials include silica or silicates. and a solvent or suspending medium. This kind of mixture silicate (e.g. sodium silicate which already contains silicate oligomers) or it can be formed slowly. However, preferably , a synthetic gel capable of producing crystalline zeo-type materials is used. This type of gel is made from silicic acid. and other ingredients. A gel of this type is used in step (i) of the method according to the invention. If used, this gel is the same as the gel used in steps (i-ii) of the method according to the invention. They can have the same composition or they can have different compositions. Preferably have the same composition. suitable for use in step (ii) of the method according to the invention Any synthetic gel as described below may be used in step (i) of the method of the invention. I can do it.

The contact between the surface of the support and the solution or suspension in step (i) is preferably carried out by Including dipping the surface of the carrier but using other methods, such as coating the surface with a solution or by keeping the suspension layer in contact with the surface until the silicate oligomers bind. Methods such as applying layers can also be used. Contact occurs when the humidity level on the surface is high. maintained relative to the liquid (e.g. by operating under autogenous pressure) to prevent the solution or suspension from drying on the surface. In step (ii) , connect the surface with bound oligomers and the solid/suspension, e.g. by gravity or by distance. Separate by heart separation. Preferably, after dipping in step (i), the support is solidified. solids/suspensions, but other methods such as drainage or filtration of solids/suspensions The method can also be used. In step (iii), the surface and the synthetic gel are brought into contact with each other by immersion. It is done by soaking, but other methods such as coating are applied in the same manner as in the above step (ii). A method can also be used, provided that contact is made until the zeo-type material crystallizes on the surface. Ru.

This type of synthetic gel is applied to a porous support under conditions that ultimately result in the formation of crystals of zeo-type material. When brought into contact (e.g. immersed) with a metal, the deposition process involves many different steps. Shiroko was tracked down. The final step is to attach the crystalline zeo-type material to the surface of the support. is the deposition of However, before this, an initial deposit of silicic acid oligomers is removed from the support. Form on the surface. Containing the raw material for silicic acid in step (i) in the method of the present invention If the solution or suspension is a synthetic gel, the support is removed from the gel at this early stage. removed and then recontacted until zeo-type crystals grow on the surface, e.g. Resoak into fresh synthetic gel according to i). Surprisingly, this two-step contact ( For example, immersion) treatment coats the surface of the porous support with a zeo-type material, which is responsible for the formation of crystalline deposits. is much greater than using only one immersion, which yields

Preferably, the support is placed between steps (ii) and (iii) of the method according to the invention. , for example by washing with water, such as distilled and/or deionized water. to remove any adherent residual solution or suspension from step (i) or i) Removal of free substances before contact in i) (e.g. immersion in synthetic gels) do. A water jet can be used. This treatment removes free substances. Deposits of silicic acid oligomers bound to the surface of the support must be sufficiently severe Of course, it must not be removed. After the washing process, the oligomer deposits are removed. Preferably, before step (iii), the support is heated at, for example, 50 to 120°C ( For example, at 802-105℃) for 1-100 minutes (for example, 5-50 minutes). or dry.

Preferably, the porous support is completely immersed in a solution or suspension containing the silicic acid raw material. and then immersed in a synthetic gel. or, if desired, one surface of the support It is also possible to contact only the solution or suspension with the gel and then with the gel.

This means, for example, that the zeo-type substance must be supported only on the inside or outside of the tube. This is useful when it is desired to make the membrane in the form of a tube.

Additionally, it contains two different zeolites, one on each side of the support. It is also useful when it is desired to create a membrane with This kind of trifunctional membrane The use of two separate membranes, each carrying a different zeolite It is equivalent to doing. Of course, the support may be a solution or suspension containing the raw material of silicic acid. It is possible to fully immerse the support in the process ( i) Contact with synthetic gel according to i).

This contact, for example with a porous support for solutions or suspensions containing raw materials of silicic acid. The surface of the carrier can be immersed more than once if desired. In this case, it is preferable solution or suspension before contact (e.g. immersion in fresh solution or suspension). Treat the surface to remove the free material after removal from the object.

The surface of the porous support is heated for a period of time such that the silicic acid oligomers bind to the surface. For example, it must be immersed in a solution or suspension containing the raw material of silicic acid. No. The optimum time required for this contact will, of course, depend on the nature of the solution or suspension used. , as well as temperature dependent. The temperature of contact can vary widely, for example from 20 to 200°C. The surroundings can change. Although room temperature is convenient, this requires considerably longer contact times. While necessary, contacting at high temperatures reduces the optimal time. Generally 3 minutes ~48 hours, such as 5 minutes to 24 hours, typically 30 minutes to 3 hours of contact (e.g. soaking time) is suitable. Therefore, in the preferred method the contact time (e.g. soaking time) and temperature at 90°C for less than 8 hours (e.g. 6 hours) ), e.g. equal to 3 minutes to 5 hours (e.g. 3 to 30 minutes) at 90°C. In that case, it is preferable to use a synthetic gel as the raw material for silicic acid, or to pre-treat as described below. Use a treated support. The raw material for silicic acid crystallizes to produce crystalline zeo-type substances. In the case of a synthetic gel suspension, the contact time binds the silicic acid oligomers at the contact temperature. but sufficient to deposit said crystalline zeo-type material as an adhesive coating. It is insufficient. Oligomers of silicic acid are bonded to the surface as an amorphous layer. on the surface Its presence in the support may be related to the support itself or may dissolve the support leaving behind oligomers. After treatment of the support, transmission or scanning electron microscopy, X-ray analysis or ED It can be viewed by AX.

Zeo-type materials are well known and often referred to as molecular sieves. these are , an extended network with molecular-sized channels connected to each other via oxygen atoms. It is characterized by having a crystal structure composed of tetragonal crystals that produce crystals. finishing film Any zeo-type material can be used in the present invention depending on the desired application. Zeolai Zeo- or aluminosilicates are the best known examples of zeo-type materials. present invention For example, LTA, FAU, SOD.

MEL, MF I or TON structure type, e.g. Zeolite Strakjar Types”, Mayer and Olsen (198 7), Polycrystal Book Service, Inc., Pittsburgh, USA. Any zeolite can be used. Zeolite ZSM-5 and and zeolites A1X and Y can be used. Other Zeo type items used Some or all of the aluminum may contain, for example, gallium, boron, zinc, or iron. or metallosilicates substituted with other metals such as titanium, as well as US No. 4061724 or Nature, Vol. 280, No. 664-665 (1979), crystalline silica with a zeo-type structure such as silicalite. Includes Kate.

Other types of zeo-type materials are crystalline aluminophosphates (“ALPo”), silico Luminophosphate (“5APOJ”) and other metalloaluminophosphates be. This type of material is known, for example, by New Developments in Zeolite. Science and Technology”, Proceedings of the 7th International Zeolite Conference. Ding, Tokyo (1986), p. 103.

Very recent models such as ALPO-8, ALPO-54 and MCM-9 The materials are shown, for example, in Zeolite, Vol. 9 (September 1989), p. 436. It can be created as follows.

A membrane is a continuous structure whose length and width are much greater than its thickness. this is a liquid Or selectively permeable to gases. Any suitable polyester having the desired physical shape. Porous supports can be used in the method of the invention. Suitable forms are e.g. Includes face sheet, tubular or spiral wound type. Suitable materials are porous metals, ceramics, cermets, glass, minerals, carbon or polymers. Yes, typical metals are stainless steel, Inconel, Bastalloy, Hueklaroy, Contains chromium and titanium. Metals are wire mesh (e.g. form of a metal wire mesh and sintered metal particles (e.g. ball PMM gold metal filters and spramesh filters) or sintered metal filters (for example Pole PSS filter media). Metal wire mesh filter media may also be used. can be used. Inconel, Bastaroy, Fueclaroy, Bekipol, Po Roll and Supramesh are registered trademarks.

Typical polymeric materials include any type of filtration media, including woven and nonwoven media. Contains. These can be coated with a thin film of metal or metal oxide if necessary. Wear.

porous carbon, silicon carbide, porous clay or other silicate minerals such as kaoli vermiculite, montmorillonite and columnar clay, aerogel or porous ceramics, glasses, including supported airgel and supported porous silica; Carbon or mineral media can be used. The support itself is zeolite It can also be formed into a suitable shape by using a suitable binder.

By selecting a suitable support, extremely robust membranes can be created. metal support Particularly preferred is the use of the body.

The pore size of the support is an important parameter. Many conventional membranes are extremely A support with small pore size was used. This invention compared with the published conventional technology. The main advantage of brightening lies in the use of supports with large pore sizes. Special Additionally, the pore size can be larger than the average crystal size of the zeo-type material. large pores allows the production of large surface area membranes and thus maximizes the flux. It is advantageous. Preferably, the average pore size of the support used in the present invention is 0. 1-2 000 μm1, preferably 1 to 2000 μm1, particularly 5 to 200 μm.

For pores up to 300 μm in diameter, pore dimensions are specified by ISO 4003. Pore size can be measured using bubble point pressure technology. The distribution can be measured with a Coulter Bolometer. Than For large pores, optical microscopy can be used.

In a particularly preferred embodiment of the invention, a solution or suspension containing the raw material of silicic acid and then in a synthetic gel that can crystallize to form a crystalline zeo-type material. The surface of the support is coated with nickel, cobalt or nickel as a metal and/or oxide. has a surface coating of molybdenum.

This surface coating that is integrated into the support is generally primarily in the form of an oxide; because nickel, cobalt or molybdenum have a tendency to oxidize in air. It is.

Preference is given to using molybdenum or especially cobalt.

The surface coating can be applied, for example, by vacuum deposition, vapor deposition, Rf sputtering or electroplating. It can be attached by any suitable method. In addition, the support can be made of a suitable metal. The adhesive layer is oxidized by immersion in a solution of salt and then baking in air. You can also wear it. Also prevents adhesion of nickel, cobalt or molybdenum metals. When using the drying technique, this initial deposit is optionally treated with an oxidizing gas (conveniently an empty It can also be converted by heating in a stream of gas to give a thick layer of oxide.

The synthetic gel used in step (ii) of the method according to the invention contains the desired crystalline zeolite. It can be any gel that can produce a mold material. To synthesize zeo-type substances gels are well known, for example from the prior art mentioned above or from EP-A-57049. No., EP-A-104800, EP-A-2899 and EP-A-290 It is stated in No. 0. D. W. Bretzk (``Zeolite Molecule Sea ``Structure Chemistry and Youth'' by Joan Willey edition, 1974) and P. A. Jacobs and J. A. Martens, “Stade Ease Innobu Surf Ace Science and Catalysis, No. 33 , “Synthesis of high syringe aluminosilicate zeolite”, Elisevir Publishing, 19 The standard textbook by 87) describes many synthetic gels of this type. present invention The method includes the conventional synthesis of zeo-type materials, except that the synthesis is performed on a porous support. done in the presence of Most commonly, heat is applied to crystallize the gel.

Although pressure can be applied, crystallization is generally carried out under autogenous pressure depending on the properties of the gel and the temperature. depending on the temperature, typically between 20 and 220°C, but especially between 60 and 120°C. Generally, time can range from 3 to 200 hours, especially from 4 to 150 hours, and at higher temperatures is characterized by a shorter time, especially at least 8 hours at 80-100°C (for example (e.g. 8 hours to 5 days), especially crystallization times of 10 to 80 hours, especially 10 to 30 hours. suitable.

Without carrying out steps (i) and (ii) (zeo-type crystals are Applicant's European Patent In patent application no. 91309239, only one soaking and crystallization step is supported. Although it produces some crystals on the surface of the body, these crystals are continuous crystals over the entire surface. not sufficient to produce crystal growth, requiring a second soaking and crystallization step . After subjecting the support to a second crystallization, more (crystals) are removed from the surface of the support or Crystals formed in the first crystallization (these crystals themselves grow directly on the support surface) ) grows from the surface. The soaking and crystallization steps can be repeated as required. and preferably can be repeated until the support surface is completely and continuously covered. Ru. In the method of the present invention, more than that obtained without steps (i) and (ii) Also, steps (i) and (ii) are followed by one soaking and crystallization step (ii). A much larger crystal coverage is obtained by performing i). Under suitable conditions, often A finished film can be obtained by a single dipping and crystallization step (ii).

However, to obtain the required area, two or more immersion and crystallization steps (iii) are required. need to be repeated. The invention therefore furthermore follows step (ii) After crystallization of the initial gel, the support is removed from the mixture and contacted (e.g. (ii) Immersion and crystallization) are repeated one or more times to obtain the desired film. There is also provided a method for producing a membrane comprising the method of the present invention, characterized in that it obtains the following.

Of course, contacting (e.g. soaking and crystallization) with the required step (iii) The number of times depends on the nature and pore size of the support, the nature of the zeo-type material and the synthesis conditions. Ru.

For example, up to 10 immersions, especially up to 4 immersions are preferred.

Use of the method according to the invention increases the initial coverage of zeo-type material and thus the finished film. Reduces the total number of contacts required to create a Furthermore, the method according to the invention comprises: Generally results in a thinner finished film than films made by other methods. This is for the membrane. improve flux.

Preferably after step (iii), after removing the support from the mixture, free substances are removed. After removal, for example by thorough washing, subsequent contact and crystallization steps (ii Do i). Additionally, the support can be dried between each immersion. at room temperature at least 12 hours, at a temperature of 30-50°C for at least 2 hours or 80-10 Drying at a temperature of 0° C. for 15 to 30 minutes is a suitable method.

The finishing film described in European Patent Application No. 91309239 by the applicant and the finished film that can be produced by the method of the invention has two different characteristics. Firstly , the zeo-type material directly contacts and binds directly to the surface of the support. join The nature of is not fully understood.

This may be primarily a chemical bond and/or a physical bond, but in any case Crystals form directly from the support surface without any intermediate "glue" or binder . This is similar to prior art membranes, for example, where preformed zeolite crystals are placed in the air on a support. EP-A-18020 in combination with the hole and operatively glued or fixed in place This is different from the membrane described in No. 0. Crystal growth in the finishing film in the applicant's concurrent application initiates at the surface of the support and crosslinks with crystals growing from the opposite side of the pores of the support. and continues outward until it forms a substantially continuous thin film of zeo-type material.

Second, in zeo-type materials, each individual crystal is separated from or adjacent to the surface of the support. It shows substantially continuous crystal growth growing from the surface of the crystal. This was also preformed Conventional techniques in which the crystals are "glued" in close contact or the surface coverage of the support is incomplete It is different from the membrane of surgery. There is an intermediate layer of amorphous material between the support and the crystal growth. do not have.

In these membranes, the growth of zeo-type material is virtually continuous throughout the pores of the support. It is. Preferably it is substantially continuous over the entire surface of the support. this place In this case, the layer of zeo-type material can be, for example, 100 μm or more thick. Wear. For example, the thickness can be from 1 to 100 μm, especially from 1 to 70 μm.

While forming a coating on the pores of the support, if desired, the growth of zeo-type material can be prevented. It is also possible to extend through the holes into the body of the support.

Preferably, crystal growth in films produced by the method of the present invention is completely pinpoint-free. Does not include rules. Of course, it is difficult to realistically create a perfect film; The term "substantially continuous" encompasses films that have a small number of pinholes during crystal growth. intended to include. This type of pinhole is used when creating a film using the crystallization method. A crack is a crack that forms when the planes of a growing crystal do not align precisely. this kind of Pinholes are present immediately after membrane preparation, but do not occur until after membrane dehydration or ion exchange. or during membrane operation. These films clearly show non-crystal growth. This differs from prior art membranes which are continuous and whose growth results in macropores.

Trace pinholes in the membrane can be removed by suitable post-treatment, e.g. with organic substances (e.g. polyamide). silicon, such as polymers or organic silicon materials) or inorganic materials (e.g. inorganic silicon materials). and can be sequestered using a substance that crosslinks with oxygen atoms).

Substantially continuous crystal growth in the finished film, supplemented with post-treatment as necessary, There are no passageways from one side of the membrane to the other, except for the intracrystalline pores of the material.

Finished films made by the method of the invention have a wide range of uses. These are analogies For dehydration to remove water from materials such as LPG, natural gas or alcohol. It can be used for. This type of membrane consists of conventionally used organic polymer membranes, For example, the commercially available cesium polyacrylate membrane described in WO86100819 It is much more effective at dehydrating mixtures of water and other liquids. these are It has the further advantage that it can be used even at relatively high temperatures.

These include, for example, fuel octane upgrading, reforming, dewaxing or Mixtures containing highly branched compounds during the separation of lumal and isobutane Used to remove linear alkanes, olefins or other functionalized hydrocarbons from can do.

The combination of catalysis and separation methods is another important application.

Examples include polymers such as isoalkanes, isoalkenes and aromatics. Involves hydrogenation and dehydrogenation of linear hydrocarbons in the presence of chemical compounds . These membranes can be used, for example, to remove hydrogen from dehydrogenation reactions or even esterification reactions. or towards the desired product by removing water from alcohol dehydrogenation. It can be used in catalytic reactions that shift thermodynamic equilibrium.

The present invention will be further explained below with reference to Examples.

The chemicals used in the examples are as follows: Sodium aluminate: nominally 40% A 12o3. BDH industrial grade containing 30% Na2O and 30% H2o, Sodium silicate: Manufactured by BDH Co., Ltd., specific gravity 1.57° The substrate used was “Membralo 3x multi-channel membrane available as SCT Type Z It was made into a 3x1cm block. This substrate is composed of α-alumina and zirconia. , has a pore size of 50 nm and further has 19 channels with an internal diameter of 4 mm. .

This block is approximately 200. The solution was soaked in a beaker containing 1 liter of toluene for 1 hour. The lock was degreased (fluid was changed 3 times). Then toluene is replaced with acetone. and the washing process was repeated. Then carefully place the block into a clean Petri dish. The samples were air-dried, covered loosely with aluminum foil and placed in a medicine cabinet overnight.

Place a clean dry block into a QVF (registered trademark) glass tube (diameter 80 cm) . Attach the PTFE end plate to this QVF tube and tighten the metal nuts and bolts. It was held in place by a stainless steel flange which was held in place by a bolt.

Clean the container by pre-rinsing it with distilled water, acetone, toluene and finally with acetone. After that, it was dried with a stream of clean dry air.

Two solutions A and B were prepared separately in two 16 oz glass bottles as follows: Created: Solution A + 34.4 g of sodium aluminate (industrial edge from BDH) and 155 ．． 0 g of distilled, deionized water.

This aluminate was analyzed with the following results: 27.44% Na 0.43.3 6%A　I　20　a and 29.2θ%H20゜ The mixture was then mechanically shaken until dissolved.

Solution B: 53.4 g of sodium silicate, specific gravity 1.57 (BDH) (analysis was 13 ．． 53%Na 20129. Shows 28% SiO and 57.20% H20 ) and 155. Og distilled deionized water.

Add solution A to solution B slowly while stirring and shaking (manually). was added to ensure complete and uniform mixing (this will prevent hydrogel clumps from forming). (This is important to ensure that the This results in a hydrogen with the following nominal molar composition: Drogel was formed: 2, ONa O: AI O: 2. O8102:143 H2O.

The molar composition based on the analytical values was as follows: 1,83 NaO:A120a : 1.78 S 102 : 132.9H20゜ The hydrogel was slowly poured into the QVF tube containing the block.

The tube was sealed with a second PTFE disc and a metal end flange and heated to 90°C for 2 Placed in a preheated oven for an hour. Then take it out and rapidly soak it in a water bath for 5-1 minutes. Cooled for 0 minutes. Open one end of this tube, pour out the solution, and The block was carefully removed with a long flat rod to ensure that the block was not damaged in any way. child Place the blocks in a glass beaker and wash three times with 100ml portions of distilled deionized water. The remaining zeolite solution was completely removed by cleaning and rotating the solution each time. then , dry this in an oven at 90°C for 20 minutes, and wipe it with tissue paper to remove any residue. quality was removed. This washing and drying was then repeated.

New solutions A and B were then used as above to create a new hydrogel. Ta. Soak the mesh in fresh hydrogel, then soak and wash as above. was repeated, except that the soaking time was 24 hours instead of 2 hours.

Inspection of the block surface using a scanning electron microscope (SEM) is performed directly on the block surface. It showed significant amounts of cubic zeolite A crystals bound together.

Example 2 (comparison) The procedure of Example 1 was repeated exactly, but with an initial soaking step (2 hours at 90°C). ) and subsequent washing was omitted. Examination of the obtained blocks by SEM was showed poor zeolite coverage.

Example 3 The procedure of Example 1 was repeated exactly, except that the block was A surface coating containing cobalt was provided.

The support was added to 500ml of 0.1M Co(NO3)2.6H20 at room temperature. Soaked for 2 hours. The support was then removed and placed in a glass Petri dish with fresh O,I A coat of MO, LMCo (No) 6HO solution was pipetted onto the surface. this The support was dried at 90° C. for 30 minutes and a second load was applied. This support was heated at 90°C. for 90 minutes, and then heated in air at 550° C. for 6 hours.

The resulting block was subjected to the procedure of Example 1 and then examined by SEM. this had a continuous surface coverage of zeolite crystals; SEM magnification ×500 is shown in Figure 1. .

Example 4 The substrate used was a Bekipol (registered trademark) ST5BL3 filter. This is the ultimate It is made up of fine 316 stainless steel fibers that come together in a three-dimensional labyrinth structure. each The fibers are randomly arranged up to a honeycomb wave. Compressing this web further Sintered together to provide an extremely strong metallic bond where each fiber intersects. coulter ・The average pore size measured by a bolometer is 5.3 μm, and the The diameter of the wire is 6.5 μm.

A 7 cm disc of this mesh was degreased as described in Example 1. next This was then added to a solution of 53.4 g of sodium silicate in 155 g of water at 90°C. and soaked for 4 hours. After removal, the mesh was thoroughly washed with water, and then the same procedure as described in Example 1 was carried out. Hydrogels made from solutions A and B were immersed as described above. Then process The same procedure as in Example 1 was carried out.

Visual inspection by SEM showed approximately 30% coverage of the pores of the support.

In the comparative experiment, the sodium silicate immersion step was omitted.

Visual inspection of the finished mesh showed approximately 20-25% coverage of the pores of the support.

Example 5 The general procedure of Example 1 was repeated using the substrate shown in Example 4. initial hydro Immersion in the gel was at 90°C for 5 minutes. removal from the initial hydrogel and After washing, the mesh was analyzed by transmission electron microscopy and X-ray analysis.

A transmission electron micrograph (magnification: 100.000) is shown in FIG. A hemispherical sphere is on the front. Shown directly bonded to a surface.

X-ray analysis showed that these spheres contained mainly silicon and oxygen. child These spheres are silicic acid oligomers.

Continuation of front page (72) Inventor: Naylor, Timozide Villiers, UK, T-Dub Ryu 200 NK, Surrey, Egham, Englefield Green, Kingswood Close 10

Claims (6)

[Claims] 1. Next step: (i) At least one surface of the porous support is coated with silicic acid oligo containing the raw material of silicic acid under conditions such that the mer binds directly to said surface of the support. (ii) a support to which said oligomer is bound; and the solution or suspension containing the silicic acid raw material; then (iii ) contacting the surface of said support with a synthetic gel capable of crystallizing to produce a crystalline zeo-type material; and induce crystallization of the gel to crystallize the zeo-type material on the surface. A method for depositing a zeo-type substance onto a porous support, characterized by: 2. Step (i) does not involve immersing the surface in the solution or suspension. and step (ii) involves removing the support from the solution or suspension. and step (iii) further comprises immersing said surface in said gel. A method according to claim 1, characterized in that: 3. Between steps (ii) and (iii), the support to which the oligomer is bound A claim characterized in that the solution or suspended matter and free substances are removed by washing the solution or suspended matter and free substances. The method according to claim 1 or 2. 4. Synthetic gel whose surface can be crystallized to produce a crystalline zeo-type substance in step (i) and soaking the oligomer for a sufficient time to bind the oligomer to the surface. The method according to any one of claims 1 to 3, characterized in that: 5. A claim characterized in that the dipping step (iii) is performed on fresh synthetic gel The method described in item 4 of the scope. 6. The porous support before step (i) contains the metal and/or its oxide. characterized by having a surface coating of nickel, cobalt and/or molybdenum The method according to any one of claims 1 to 5.