JP4454173B2 - Method for producing extrusion molded body - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an extruded product.
[0002]
[Prior art]
The present applicant has continued research on mass production of an electrochemical cell having a complicated shape by an extrusion method and putting it into practical use. For example, Japanese Patent Laid-Open No. 10-286812 discloses a ceramic laminated body extrusion molding apparatus using a biaxial plunger mechanism. Japanese Patent Application Laid-Open No. 11-40175 describes an apparatus and a die for extruding an electrochemical cell. Japanese Patent Application Laid-Open No. 10-40934 discloses an electrochemical cell including a honeycomb-shaped substrate. Further, it is described that such an electrochemical cell is formed by an extrusion method.
[0003]
[Problems to be solved by the invention]
In Japanese Patent Application Laid-Open No. 10-40934, the form of an electrochemical cell having a honeycomb-shaped substrate is disclosed, and there is a statement that such a cell is formed by an extrusion molding method. It is difficult to efficiently extrude the molded body. In JP-A-11-40175, it is described that a plurality of types of materials having different properties (that is, a base material and a film material) are joined together in a die and laminated, but a honeycomb-shaped electrochemical cell is described. Thus, it has not yet been disclosed an extrusion apparatus suitable for efficiently extruding a molded body having a particularly complicated shape.
[0004]
An object of the present invention is to provide a new method for efficiently extruding a film on each wall surface of each space of a honeycomb substrate.
[0005]
[Means for Solving the Problems]
The present invention is a method for producing an extruded body comprising a honeycomb substrate made of a first material and a film made of a second material formed on the wall surface of the substrate,
When the cross section orthogonal to the extrusion axis of the extruded product is viewed, a plurality of closed spaces are formed in the base, and when viewed from the cross section orthogonal to the extrusion axis, the closed space is faced. Wall surface to be divided into a plurality of flat surfaces intersecting each other at a predetermined angle,
Using a base provided with a first path for extruding the first material and a second path for extruding the second material;
The first path includes a supply part for supplying the first material, and a honeycomb-shaped void part for forming the first material flowing in from the supply part,
The second path includes an upstream inlet portion corresponding to each closed space , a downstream outlet portion located downstream of the base and extending alongside the gap , and each inlet portion and outlet portion. It has a plurality of connecting portions that connect and extend in a direction substantially perpendicular to the direction of the extrusion shaft, and each connecting portion extends from the inlet portion toward the outlet portion in correspondence with a plurality of flat surfaces. ,
At the same time as forming the substrate in the void by extruding the first material in the first path, the second material is fed from each connection to the outlet and the membrane is extruded by extruding from the outlet. It is characterized by being formed continuously on each flat surface of the substrate.
[0006]
By using such a die, the film can be efficiently extruded on each flat surface facing the closed space of the honeycomb substrate when the substrate and the film are simultaneously extruded. The film formed simultaneously with the substrate by such an extrusion molding method can accurately control the film thickness, and in particular, can generally form a thick film as compared with the dip coating method. Further, in the case of the dip coating method, distribution or deviation in the thickness of the film inevitably occurs in the longitudinal direction of the substrate. There is no deviation in thickness in the longitudinal direction. Accordingly, an appropriate amount of the second material can be supplied to each flat surface.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the drawings as appropriate. In the present invention, the substrate has a honeycomb shape. Further, a plurality of connecting portions are provided in the base for each flat surface facing one closed space. When viewed from a cross section orthogonal to the extrusion axis, the substrate wall surface facing the closed space is divided into a plurality of flat surfaces intersecting each other at a predetermined angle, and a separate connection portion is provided for each flat surface. Is provided. Accordingly, an appropriate amount of the second material can be supplied to each flat surface.
[0008]
Further, the connecting portion extends in a direction substantially perpendicular to the extrusion shaft. Such a form can be easily formed by plugging the outlet end of the die and forming a through hole in the die in a direction substantially perpendicular to the extrusion shaft.
[0009]
1 to 11 relate to a preferred embodiment of the present invention. FIG. 11 is a perspective view schematically showing the base 1. 1 to 6 are cross-sectional views (cross-sectional views) of the base 1 taken along a cross section perpendicular to the longitudinal direction A, taken along lines II and II- in FIG. 11, respectively. This corresponds to a cross section taken along line II, III-III, IV-IV, VV, and VI-VI. 7 and 8 are cross-sectional views (longitudinal cross-sectional views) of the base 1 cut in a direction horizontal to the longitudinal direction A, and are cross-sections cut along the lines VII-VII and VIII-VIII, respectively. It corresponds to. 9 and 10 are cross-sectional views (longitudinal cross-sectional views) of the base 1 cut in a direction horizontal to the longitudinal direction A, and are cross-sections cut along lines IX-IX and XX, respectively. It corresponds to. The longitudinal direction A of the die 1 is also an extrusion shaft.
[0010]
FIG. 12 is a cross-sectional view showing a typical extruded product 11 formed by the die 1. The molded body 11 includes a honeycomb-shaped substrate 9. The substrate 9 includes a plurality of, for example, nine closed spaces 8 in this example.
[0011]
In this example, the number of closed spaces 8 is nine, but of course the number is not limited. In this example, the shape (transverse cross-sectional shape) of each closed space 8 is substantially square or rectangular. The shape may be On the wall surface (inner wall surface) 7 on the side of each closed space 8 of the substrate 9, a film 6 is formed over the entire circumference, and a closed space 10 is formed inside the film 6. The substrate 9 is made of a first material, and the film 6 is made of a second material. The film 6 does not need to be provided over the entire circumference of each inner wall surface 7, and may be provided only on a part of the inner wall surface 7 in each closed space 8.
[0012]
The first material constituting the substrate 9 may be one type over the entire substrate 9, or two or more types. The second material constituting the film 6 may be one kind over the whole film 6, or two or more kinds. The membrane 6 may be made of a different material for each closed space 10.
[0013]
Hereinafter, the form of the base 1 and the flow of each material will be described. A material supply device (not shown) is installed before or upstream of the base 1. For example, as described in JP-A-10-286812, each material can be independently supplied to the base 1 by a plunger using a hydraulic cylinder. In the base 1, a first path 4 for extruding the first material 5 and a second path 3 for extruding the second material 6 are formed. The first material 5 first enters the circular path 4A shown in FIG. The path 4A is arranged in the vertical direction, for example. The material 5 proceeds downstream as shown in FIGS. 2, 3, 8, and 9, and then spreads in the path 4B as shown in FIGS. The cross-sectional shape of the path 4B is a honeycomb shape as shown in FIG. 4, and corresponds to the cross-sectional shape of the substrate 9 shown in FIG. As shown in FIGS. 5 and 6, the first material 5 proceeds while substantially maintaining this shape, and is discharged from the downstream end face of the base 1.
[0014]
On the other hand, the second material 6 is supplied from an inlet 3 </ b> A that opens on the upstream side of the base 1, as shown in FIGS. 1, 7, 9, and 10. The inlet portion 3A has an elongated shape on the end face as shown in FIG. 1, but as shown in FIGS. 2 and 7, it becomes circular in cross section as shown in 3B from the middle. Then, as shown in FIGS. 3 and 4, a path 3B having a circular cross section continues. Next, as shown in FIG. 5, for example, four connection portions 15 </ b> A to 15 </ b> D are formed for each closed space 8.
[0015]
In this example, for each closed space 8, four flat surfaces 7 a-7 d intersecting each other, preferably orthogonal, are formed on the wall surface 7. And the 2nd material 6 is supplied to each flat surface 7a, 7b, 7c, 7d through each connection part 15A, 15B, 15C, 15D, respectively. In this example, at the end of each connecting portion, an elongated gap 20 is formed between the base body 2 and the inner side of the first path 4B for flowing the material 6 in advance. For this reason, the material 6 flows into the gap 20 and is molded in the gap 20 between the material 5 flowing in the path 4B and the base 1. As a result, the first material and the second material are merged and laminated.
[0016]
In this way, in the present invention, by providing a gap between the base and the first path at the downstream end of the connection portion, the flow of each material is stabilized, and in particular, the thickness of the substrate is fluctuated. Can be suppressed.
[0017]
Next, as shown in FIGS. 6, 7, and 9, the second material 6 is controlled to have a constant film thickness, formed into a film shape, and extruded to the downstream side of the die together with the honeycomb-shaped substrate 9. In this example, as shown in FIG. 7, a plugging portion 21 is formed at the downstream end of each second path 3, thereby stopping the flow of the material 6 that has traveled straight through the inlet 3A, It is made to flow toward the connecting portions 15A-15D. Such a plugged portion itself can be formed by a known method after the second path 3 is once penetrated in the direction of the extrusion axis A.
[0018]
Although the use of the extruded product obtained by the present invention is not particularly limited, for example, an electrochemical cell can be exemplified. Examples of the electrochemical cell include an oxygen pump, a high-temperature steam electrolysis cell, a hydrogen generation device, a water vapor removal device, a solid oxide fuel cell, and a NOx decomposition cell.
[0019]
In the case of an electrochemical cell, for example, in FIG. 12, the substrate 9 can be formed of a solid electrolyte material and a dense conductive material, and the film 6 can be formed of an electrode material.
[0020]
As the solid electrolyte material, cerium oxide ceramics, yttria stabilized zirconia, and yttria partially stabilized zirconia are preferable, but other materials can also be used. The dense conductive material is preferably a perovskite complex oxide containing lanthanum, and more preferably lanthanum chromite. It is because it has heat resistance, oxidation resistance, and reduction resistance.
[0021]
The electrode material is preferably a perovskite complex oxide containing lanthanum, more preferably lanthanum manganite or lanthanum cobaltite, and even more preferably lanthanum manganite. Lanthanum chromite and lanthanum manganite may be doped with strontium, calcium, chromium (in the case of lanthanum manganite), cobalt, iron, nickel, aluminum or the like. Moreover, nickel, nickel-zirconia mixed powder, palladium, and nickel-zirconia cermet are preferable.
[0022]
When an aqueous binder is used for the material for extrusion, there is no need to perform an exhaust treatment as in the case of using an organic solvent, so that the equipment can be simplified and the laminated molded body extruded from the die becomes difficult to bend. In this case, the water content is more preferably 10 to 20% by weight. Examples of the aqueous binder include polyvinyl alcohol, methyl cellulose, and ethyl cellulose.
[0023]
Examples of the organic binder include polymethyl acrylate, nitrocellulose, polyvinyl alcohol, methyl cellulose, ethyl cellulose, starch, wax, acrylic acid polymer, and methacrylic acid polymer.
[0024]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a new method for efficiently extruding a film on each wall surface of each space of a honeycomb substrate. According to the present invention, an appropriate amount of the second material can be supplied to each flat surface.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the shape of the vicinity of the inlet of a base 1 and corresponds to the II cross section of FIG.
2 is a cross-sectional view of the base 1 and corresponds to the II-II cross section of FIG.
3 is a cross-sectional view of the base 1 and corresponds to a section taken along line III-III in FIG.
4 is a cross-sectional view of the base 1 and corresponds to the IV-IV cross section of FIG.
5 is a transverse sectional view of the base 1 and corresponds to a VV section in FIG.
6 is a cross-sectional view of the base 1 and corresponds to a VI-VI cross section of FIG.
7 is a longitudinal sectional view of the base 1 and corresponds to a VII-VII section of FIG.
8 is a longitudinal sectional view of the base 1 and corresponds to the VIII-VIII section of FIG.
9 is a vertical cross-sectional view of the base 1 and corresponds to a IX-IX cross section of FIG.
10 is a vertical cross-sectional view of the base 1 and corresponds to the XX cross section of FIG.
FIG. 11 is a perspective view schematically showing a base 1.
FIG. 12 is a cross-sectional view schematically showing an extruded product 11.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base 2 Base body 3 2nd path | route 3A, 3B Inlet part 3C, 3D Outlet part 4 1st path | route 5 1st material 6 2nd material 7 Wall surface 7a, 7b, 7c facing the closed space of a base | substrate 7d Flat surface of wall surface 8 Closed space 15A, 15B, 15C, 15D Connection portion 20 Air gap A Extrusion shaft

Claims (2)

A method for producing an extruded body comprising a honeycomb substrate made of a first material and a film made of a second material formed on a wall surface of the substrate,
A plurality of closed spaces are formed in the base when viewed from a cross section orthogonal to the extrusion axis of the extruded molded body, and when viewed from a cross section orthogonal to the extrusion axis, The wall surface facing the closed space is divided into a plurality of flat surfaces intersecting each other at a predetermined angle;
Using a base provided with a first path for extruding the first material and a second path for extruding the second material;
The first path includes a supply part for supplying the first material, and a honeycomb-shaped void part for forming the first material flowing in from the supply part,
The second path connects the upstream inlet portions corresponding to the closed spaces, the downstream outlet portions extending alongside the gaps , the inlet portions and the outlet portions; and A plurality of connecting portions extending in a direction substantially perpendicular to the direction of the extrusion shaft, the connecting portions extending from the inlet portion toward the outlet portion corresponding to the plurality of flat surfaces; And
At the same time as forming the base in the gap by extruding the first material in the first path, the second material is supplied from each connection to the outlet, and the outlet A method for producing an extruded product, wherein the film is continuously formed on each flat surface of the substrate by extruding from a part .   The method according to claim 1, wherein at least one of the first material and the second material is made of a plurality of types of materials.

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