JP4836085B2 - Stamp type film forming method - Google Patents

Description

The present invention relates to a stamp-type film forming method using a stamp surface. More specifically, the present invention relates to a stamp surface impregnated with a coating agent made of a metal or a ceramic material, a flat surface or a curved surface, and an uneven surface. by contacting the porous substrate surface made of a ceramic material, to the appropriate location of the substrate surface, new casting method and film formation member or the like make it possible to film the homogeneous and緻dense coating layer It is about.

  Conventionally, porous ceramics are used as a support for, for example, gas phase separation, exhaust gas purification / water purification filters, and the like. Among these, a honeycomb shape in which hollow tubes are integrated is widely used as a support shape of porous ceramics because an increase in filter area per unit volume can be expected.

  In general, in the filter method using a porous ceramic wall, a gas phase or a liquid phase containing an impurity is supplied to about half of the honeycomb pores that are not sealed, and the impurity is removed by the porous wall. The gas phase or liquid phase passes through the remaining half of the sealed honeycomb holes and is discharged. In addition, as a prior art, as a honeycomb type gas separation membrane that does not require a support for supporting the gas separation membrane, a honeycomb integrated structure is used, and a dense body made of a material having gas separation ability is used to identify from a mixed gas. A gas separation structure for separating or supplying gas has been proposed (Patent Document 1).

  In order to improve the separation performance in this type of gas separation membrane, it is necessary to prevent the entry of a gas phase or liquid phase containing impurities from the end surface portion of the porous ceramic wall. It is necessary to form a dense film on the porous ceramic wall of the honeycomb end face without sealing.

  Moreover, a solid oxide fuel cell (SOFC) is mentioned as a system using the same gas phase separation. In order for the SOFC to operate, it is necessary to separate an oxidizing gas such as air and a fuel gas such as hydrogen by a dense film having no electron conductivity.

  In recent years, one of the methods for increasing the output of SOFC that has been demanded is an integrated structure of micro SOFC. As a method for integrating micro SOFCs, mainly, (1) accumulation of tubular microcells using a porous current collecting support made of metal or ceramics, and (2) tubular using a porous honeycomb current collector made of metals or ceramics. There is an accumulation of channel cells. However, in both integrated structures, it is necessary to form a gas separation membrane on the end face part of the porous support, and since it has a complicated support shape compared to a conventional structure such as a flat plate type SOFC, it is more sophisticated. A gas separation membrane forming technique is required.

  Currently, film forming methods on a substrate surface that are widely used include, for example, dipping, screen printing, spray coating, spin coating, ink jet, and brush coating.

  The dip method, spray coating method, and spin coating method can form a very beautiful coating layer on the surface of a substrate having a relatively simple surface such as a flat surface or a curved surface. However, in the case of a base material having a complicated shape such as a honeycomb, there is a problem that an excessive coating agent remains in the honeycomb holes and plugs the honeycomb channels.

  Further, in the screen printing method, since pressure is applied to the surface of the base material during printing, a brittle base material cannot be used. In the case of brush coating, in order to prevent the solidification of the brush due to drying of the coating agent, it is necessary to perform continuous work, which is limited as an industrial process.

  On the other hand, there is an ink-jet film forming method as a method capable of non-contact and pattern formation. This technique can be applied to a substrate having a complex surface as a technique for forming a film by discharging a coating liquid on demand. However, in the ink-jet film forming method, it is necessary to change the pattern setting whenever the substrate shape is changed, and the substrate is required to have very high shape accuracy. Still a disadvantageous approach.

JP 2001-104742 A

  Under such circumstances, the present inventors have developed a new film forming method on the surface of a porous substrate made of a metal or a ceramic material of a coating agent made of a metal or a ceramic material, in view of the above-described conventional technology. As a result of accumulating intensive research, we have developed a film-forming method that forms a metal or ceramic film with high accuracy only on the surface of a substrate having a complex shape without measuring the shape of the substrate surface in advance. The present invention has been completed successfully.

  The present invention not only forms a film on a flat or curved surface, but also does not use masking without measuring the shape of the substrate surface even on a porous substrate surface such as a honeycomb opening having a complicated shape. In addition, an object of the present invention is to provide a film forming method capable of selectively forming a coating agent as a coating layer at an appropriate location on the surface of a substrate without sealing the honeycomb channel, and a film forming member thereof. To do.

The present invention for solving the above-described problems comprises the following technical means.
(1) In a film-forming method that can be used for forming a SOFC porous current collecting support, a metal or ceramic material that can be used for forming the support to an appropriate location on the surface of a substrate made of a metal or ceramic material when forming a film as a coating layer coating agent having the structure of dense consisting a stamp surface impregnated with the coating agent, by contacting the substrate surface, where appropriate on the surface of the substrate to, a casting method selectively film the coating layer,
1) The substrate is porous, the porosity is 1 to 50%, the pore diameter is more than 0 to 5 microns, and 2) the coating agent is a particulate material that is a raw material for the coating film. It is a slurry coating agent containing a coating material or a solution coating agent in which metal ions as a raw material for the coating film are dissolved. It is made of a cotton-like material, and the pore diameter of the stamp material constituting the stamp is in the range of 10 to 100 microns. 4) The geometric shape of the substrate surface is measured in advance to The film forming method according to claim 1, wherein a coating layer is formed on the surface of the substrate by bringing the stamp surface and the substrate surface into contact with each other without forming a geometric shape on the stamp surface.
(2) the substrate surface is planar or irregular surface consists of a complex surface having a song surface, or a honeycomb shape, and a method of producing the film according to (1).
( 3 ) The film forming method according to (1), wherein the coat layer is formed by contact between the stamp surface and the substrate surface without applying a stress load to the substrate surface.
( 4 ) A metal or ceramic that can be used for film formation of the support to an appropriate location on the surface of a base material made of a ceramic material using the film formation method according to any one of (1) to (3). A film forming member formed by forming a coating agent made of a material as a coating layer through a stamp surface impregnated with the coating agent ,
1) The base material is a honeycomb porous base material, the porosity is 1 to 50%, the pore diameter is more than 0 to 5 microns, and 2) the coating agent is a raw material for the coating film. A slurry coating agent containing a particulate coating material or a solution coating agent in which metal ions as a raw material of the coating film are dissolved. 3) The stamp surface is a curved surface or a flat surface and has a porosity of 70 to 90%. It is made of a sponge-like material or a cotton-like material, and the pore diameter of the stamp material constituting the stamp is in the range of 10 to 100 microns. 4) The coat layer has a dense structure. A film-forming member having a film-forming structure in which the coating agent on the stamp surface impregnated with the coating agent is selectively formed as a coating layer only on a predetermined portion of the substrate surface .

Next, the present invention will be described in more detail.
The present invention is a film forming method for forming a coating agent made of a metal or a ceramic material as a coating layer on an appropriate portion of a substrate surface made of a metal or a ceramic material, the stamp surface impregnated with the coating agent, The coating layer is formed on an appropriate portion of the substrate surface by bringing the substrate surface into contact therewith.

  Further, the present invention is a film forming member in which a coating agent made of a metal or a ceramic material is formed as a coating layer on an appropriate portion of the substrate surface made of a metal or a ceramic material, and the stamp surface impregnated with the coating agent This coating agent is characterized by having a film-forming structure in which a film is formed as a coating layer only at a predetermined location on the surface of the substrate.

  Further, the present invention is a stamp for forming a coating agent made of metal or ceramic material as a coating layer on an appropriate portion of the substrate surface made of metal or ceramic material, the stamp surface from a curved surface or a flat surface Thus, the porosity is 70 to 90%, and the pore diameter of the stamp material constituting the stamp is in the range of 10 to 100 microns.

  The film forming method of the present invention is a method for forming a film as a coating layer by bringing the surface of a porous substrate into contact with a stamp surface impregnated with a coating agent made of a metal or a ceramic material. In the present invention, as the porous substrate, it is possible to use not only a smooth surface such as a flat surface or a curved surface, but also a porous substrate having a complicated surface having a complicated shape typified by a honeycomb. In addition, it is possible to form a film only on the substrate on the surface.

  As a material of the base material, any metal or ceramic can be used without limitation. As specific examples thereof, for example, Pt, Pd, Ag, Ba, Sr, Ca, Mg, K, Na, Mn, Fe, Co, Ni, Cu, Zn, Ti, Al, Ga, Nb, A metal containing at least one element of Ta, V, La, or an oxide containing one or more of these elements, or a metal containing one or more of these elements and an oxide containing one or more of these elements; The complex or cermet is exemplified.

  The porosity of the substrate is preferably 1 to 70%, and preferably 10 to 50%. The pore diameter of the porous substrate is preferably 5 microns or less, that is, more than 0 to 5 microns.

  As a material for the stamp impregnated with a coating agent made of a metal or a ceramic material, for example, a sponge-like material or a cotton-like material having a porosity of 70 to 90%, or a material equivalent or similar thereto is exemplified. The The stamp surface is preferably free of irregularities such as a flat surface or a curved surface. It is not necessary to measure the geometric shape of the substrate surface in advance and form the geometric shape on the stamp surface.

  The pore diameter of the stamp material is preferably in the range of 10 to 100 microns. Further, as will be described later, in order to utilize the difference in capillary action between the stamp material and the porous substrate, 10 to 20 microns. Preferably it is micron.

  As the coating agent made of the metal or ceramic material, (1) a slurry coating agent containing a particulate coating material as a raw material for the coating film, (2) a solution coating agent in which metal ions as the raw material for the coating film are dissolved, However, in order to prevent a large amount of the coating agent from penetrating into the porous substrate, the slurry coating agent of the above (1) is preferably used.

  As the material of the coating film made of the metal or ceramic material, metal or ceramic, for example, preferably, for example, Pt, Pd, Ag, Ba, Sr, Ca, Mg, K, Na, Mn, Fe, A metal containing at least one element of Co, Ni, Cu, Zn, Ti, Al, Ga, Nb, Ta, V, La, Si, B, an oxide containing one or more of these elements, or these A complex or cermet of a metal containing one or more of these elements and an oxide containing one or more of these elements is exemplified. However, it is not limited to these.

  As a solvent for the coating agent made of the above metal or ceramic material, any solvent that satisfies the condition that does not dissolve the base material can be used without limitation, and any solvent can be appropriately selected according to the purpose. To do.

Here, the liquid retention effect due to the capillary phenomenon of the porous substrate is expressed by the following formula 1, and the liquid retention force increases in inverse proportion to the capillary radius.
ΔP = 2σ cos α / r (Formula 1)
ΔP: liquid holding power, σ: surface tension of coating liquid, α: contact angle, r: capillary radius

  In the present invention, since the pore diameter of the stamp material constituting the stamp, that is, the capillary radius is in the range of 10 to 100 microns, the pore diameter of the porous substrate, that is, the capillary radius is about 5 microns or less. The principle that the coating agent is formed as a coating layer on the surface of the porous substrate by bringing the stamp surface impregnated with the coating agent into contact with the surface of the substrate by the capillary radius ratio is utilized. The deposition thickness of the coating film can be controlled in the range of 1 to 50 microns by the capillary radius ratio, the coating agent concentration, and the contact time between the stamp surface and the porous substrate.

  With respect to film formation on an uneven substrate surface such as a honeycomb, it is preferable that the convex pitch of the substrate is about 200 microns or more. This can be explained by using the above-mentioned formula 1. In the present invention, compared with the case where the pore diameter of the stamp material, that is, the capillary radius is in the range of 10 to 100 microns, the convex pitch of the porous substrate, that is, Since the capillary radius is about 200 microns or more, the coating agent is formed only on the surface of the base material without coating an unnecessary coating agent on the concave portion of the porous base material depending on the capillary radius ratio. This principle is used.

The present invention has flat or curved surface, an uneven surface, with respect to the porous substrate surface made of a metal or ceramic material, as a method for film formation of the coating layer made of metallic or ceramic material, made of a metallic or ceramic material It has a stamp surface that is impregnated with a coating agent, a plane or curved surface, an uneven surface, by contacting the porous substrate surface made of metal or ceramic material, to the appropriate location of the substrate surface, homogeneous and緻tight A method for forming a coating layer is established and provided.

  Furthermore, the present invention is a stamp for forming a coating agent made of a metal or a ceramic material as a coating layer on an appropriate portion of the surface of a base material made of a metal or a ceramic material. A metal or ceramic material with a coating agent made of a metal or ceramic material, wherein the porosity of the material is 70 to 90%, and the pore diameter of the stamp material constituting the stamp is in the range of 10 to 100 microns. A stamp for forming a film on the surface of a porous substrate is provided.

According to the present invention, the following effects can be obtained.
(1) A coating agent made of a metal or a ceramic material can be selectively formed as a coating layer on an appropriate location on the surface of the porous substrate made of a metal or a ceramic material.
(2) There is no need to measure the geometric shape of the substrate surface in advance.
(3) Since the stress load during film formation on the substrate is small, it can also be applied to a porous substrate having low strength.
(4) For example, a coating layer can be selectively formed on a porous substrate such as a honeycomb opening surface without sealing the honeycomb channels, so that masking is not required and film forming costs are reduced. can do.
(5) New production on the surface of a porous base material that enables high-precision film formation using a coating agent made of metal or ceramic material as a coating layer at an appropriate location on the surface of the base material made of metal or ceramic material Membrane technology and its products can be provided.

  EXAMPLES Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to the following examples.

  In the present invention, first, a coating agent made of a ceramic material was prepared according to the following procedure. That is, a rare earth-stabilized zirconia (hereinafter referred to as LnSZ), which is a kind of ceramic material, is ball milled together with an ethanol main solvent, and a commercial PVB binder and a surfactant are further mixed to prepare an LnSZ coating agent. did.

  Next, preparation of a honeycomb substrate made of a ceramic material used as a porous substrate will be described. Lanthanum manganate (hereinafter referred to as LSM), which is a kind of ceramic material, was kneaded with water and commercially available ethyl cellulose and pressure-extruded to obtain a honeycomb-shaped formed body. As material dimensions, a pore diameter of 800 microns and an LSM wall thickness of 200 microns were selected. The honeycomb-shaped formed body was cut to an appropriate length and calcined at 1000 ° C. to prepare an LSM honeycomb-shaped porous substrate.

  A cotton-like stamp material impregnated with the prepared LnSZ coating agent and having a porosity of 80% and a pore diameter in the range of 10 to 50 microns is brought into contact with the above-mentioned LSM honeycomb porous substrate surface for 1 second. By separating, an LnSZ layer was formed only on the wall surface of the honeycomb-like porous substrate.

  FIG. 1 shows a film formation state of a sample obtained by firing an LSM honeycomb porous substrate having an LnSZ layer formed thereon at 1300 ° C. By utilizing the difference in capillary action between the stamp material and the base material, which is a feature of the present invention, it is possible to form a beautiful film on the base material surface without measuring irregularities on the base material surface in advance. I understand.

Comparative Example 1
As a comparative example, the result of trying a dip method which is one method of the film forming method will be described. That is, the LSM honeycomb porous substrate prepared by the same method as in Example 1 is dip-coated at a pulling rate of 1.5 mm / sec into the LnSZ slurry prepared by the same method as in Example 1. gave.

  FIG. 2 shows a sample obtained by firing the LSM honeycomb porous substrate coated with the LnSZ layer at 1300 ° C. FIG. It can be seen that the LnSZ coating agent not only applied the surface of the honeycomb-like porous substrate but also sealed the honeycomb channels.

Comparative Example 2
As a second example of the comparative example, a result of trying a screen printing method which is one method of the film forming method will be described. First, LnSZ was ball milled together with a polyethylene glycol solvent and a commercially available ethyl cellulose binder to prepare a paste-like coating agent. This was screen-printed on the surface of the LSM honeycomb porous substrate prepared in the same manner as in Example 1 using a 200 mesh screen.

  FIG. 3 shows a sample obtained by firing the LSM honeycomb porous substrate coated with the LnSZ layer at 1300 ° C. FIG. Although the LnSZ coating agent is coated on most of the surface of the honeycomb-shaped porous substrate, some of the honeycomb channels are sealed, and no LnSZ film is present on the surface of some of the LSM porous substrates. I can see the situation.

  These are considered to be because a part of the LSM porous substrate collapses and sticks to the screen side as a result of pressure being applied to the brittle LSM porous substrate surface during screen printing. FIG. 4 shows a state in which a part of the LSM porous substrate is broken by the screen printing method and stuck to the screen side. Here, the black pattern is a collapsed LSM porous substrate. FIG. 5 shows an enlarged view of the LnSZ coat film formed on the surface of the LSM porous substrate by the screen printing method. As shown in FIG. 5, it can be seen that the LSM porous substrate collapses due to the pressure applied during screen printing.

As described above in detail, the present invention relates to a film forming method capable of forming a coat film on a porous substrate surface made of a metal or a ceramic material by a very simple method. By contacting a stamped surface impregnated with a coating agent made of a metal or a ceramic material, and a porous substrate surface made of a metal or a ceramic material having a flat surface, a curved surface, or an uneven surface, an appropriate location on the surface of the substrate to, it is possible to film the homogeneous and緻dense coating layer. In the present invention, it is possible to form a coating layer on a porous substrate surface such as a honeycomb opening surface having a complicated shape without masking and without sealing the honeycomb channel. . The present invention is useful not only as a technique for improving the performance of gas phase separation and exhaust gas purification / water purification filters, but also as a film forming technique that is indispensable for future SOFC development.

The LnSZ coat film formed on the surface of the LSM porous substrate by the stamp method is shown. The LnSZ coat film formed on the surface of the LSM porous substrate by the dip method is shown. The LnSZ coat film formed on the surface of the LSM porous substrate by the screen printing method is shown. A part of the LSM porous substrate collapses due to the screen printing pressure and sticks to the screen side (black pattern is LSM). The enlarged view of the LnSZ coat film formed into the LSM porous base material surface by the technique of a stamp method is shown.

Claims (4)

In a film forming method that can be used for forming a SOFC porous current collecting support, a coating made of a metal or ceramic material that can be used for forming the support is applied to an appropriate location on the surface of the substrate made of a metal or ceramic material. agent in the course of film production of the as-coated layer having a structure of dense, a stamp surface impregnated with the coating agent, by contacting the substrate surface, to the appropriate location of the substrate surface, the a selectively film to that casting method a coating layer,
1) The substrate is porous, the porosity is 1 to 50%, the pore diameter is more than 0 to 5 microns, and 2) the coating agent is a particulate material that is a raw material for the coating film. It is a slurry coating agent containing a coating material or a solution coating agent in which metal ions as a raw material for the coating film are dissolved. It is made of a cotton-like material, and the pore diameter of the stamp material constituting the stamp is in the range of 10 to 100 microns. 4) The geometric shape of the substrate surface is measured in advance to The film forming method according to claim 1, wherein a coating layer is formed on the surface of the substrate by bringing the stamp surface and the substrate surface into contact with each other without forming a geometric shape on the stamp surface. The substrate surface, flat or irregular surface, consists of a complex surface having a song surface, or a honeycomb shape, film forming method according to claim 1.   The film forming method according to claim 1, wherein the coating layer is formed by contact between the stamp surface and the substrate surface without applying a stress load to the substrate surface. A coating agent made of a metal or a ceramic material that can be used for film formation of the support is applied to an appropriate location on the surface of the base material made of a ceramic material using the film forming method according to any one of claims 1 to 3. A film forming member formed as a coating layer through a stamp surface impregnated with the coating agent ,
1) The base material is a honeycomb porous base material, the porosity is 1 to 50%, the pore diameter is more than 0 to 5 microns, and 2) the coating agent is a raw material for the coating film. A slurry coating agent containing a particulate coating material or a solution coating agent in which metal ions as a raw material of the coating film are dissolved. 3) The stamp surface is a curved surface or a flat surface and has a porosity of 70 to 90%. It is made of a sponge-like material or a cotton-like material, and the pore diameter of the stamp material constituting the stamp is in the range of 10 to 100 microns. 4) The coat layer has a dense structure. A film-forming member having a film-forming structure in which the coating agent on the stamp surface impregnated with the coating agent is selectively formed as a coating layer only on a predetermined portion of the substrate surface .