JPH0776704A - Method and device for manufacturing porous metallic continuous body - Google Patents

Abstract

PURPOSE:To prevent the breakage caused by shrinkage at the time of burning by forming transversel waves having a constant waving ratio on a band-like foamed resin impregnating and coating liquid slurry containing metallic powder. CONSTITUTION:Prior to the burning, the transversal waves having 14-30% waving ratio shown with the equation are formed on the band-like foamed resin impregnating and coating the liquid slurry. The waving is obtd. by pressing the band-like foamed resin 1 with a pressing roller 3 to the waving mold on the gear-like wave mold roller 2 while heating with a heater 4, reducing the moisture in the slurry contained in the band-like foam resin and increasing the slurry viscosity to form wavy shape corresponding to the wave mold. As the band-like foamed resin 1 forming the transversal waves is laid on the conveying table with the wave mold roller 2 by rotation of the wave mold roller 2 (the arrow mark 10), this wavy shaped foamed resin is continuously charged into a burning furnace.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a band-shaped porous metal (continuous porous metal body) having three-dimensional mesh-like communicating holes. This porous metal can be used, for example, as an electrode of a battery, a catalyst or a filter. Since the porous metal continuum is a strip-shaped continuum, it is possible to continuously perform cutting with high efficiency and high yield when, for example, collecting electrodes, catalysts or filters of a fixed-size battery by cutting. Is preferred.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 38-17554 discloses a method for producing a porous metal, in which a foamed resin is coated with a metal or a metal compound, dried and fired. This firing is performed in order to thermally decompose and eliminate the organic matter in the foamed resin and the slurry, and to sinter the metal powder in the slurry to bond them to each other, but a large shrinkage occurs during the thermal decomposition of the organic matter in the foamed resin and the slurry. Shrinkage also occurs when the metal in the slurry is sintered.

In the case of a small and single porous metal, this shrinkage does not cause a great problem, but in the case of a continuous porous metal, the following problems occur. That is, since the strip-shaped foamed resin impregnated with the slurry is kept in the firing furnace for a long time from the start of thermal decomposition of the organic substance to the completion of sintering, the firing furnace becomes long. Further, since the band-shaped foamed resin impregnated with the slurry during this period is fragile, it is necessary to place it on a carrying table such as a metal belt. However, when a long strip-shaped foamed resin impregnated with a slurry is placed on a long transport table and baked, the strip-shaped foamed resin being fired shrinks greatly in the length direction, but the band-shaped foamed resin being fired Since the free movement with respect to the transport table due to contraction is restricted by, for example, a frictional force, the fracture occurs on the transport table. According to the knowledge of the inventors of the present invention, the band-shaped foamed resin having a length of 2 m or more breaks due to the shrinkage during firing unless special measures are taken.

[0004]

DISCLOSURE OF THE INVENTION According to the present invention, a porous metal continuum is produced by impregnating and applying a slurry liquid containing a metal powder to a band-shaped foamed resin, drying and firing the resin in a long firing furnace. In doing so, it is an object to provide a method for producing a continuous porous metal body and an apparatus for the same, which does not break due to shrinkage during firing.

[0005]

Means and Actions for Solving the Problems In the present invention, when a band-shaped foamed resin is impregnated with a slurry liquid containing a metal powder, dried and baked in a baking furnace, the metal powder is mixed prior to the baking. The band-shaped foamed resin impregnated with the slurry liquid containing the resin has a corrugation rate of 14 to 3 represented by the following formula (1).
A method for producing a continuous porous metal body, which comprises forming a transverse wave of 0%.

Corrugation rate = {(L ₁ −L ₂ ) / L ₁ } × 100 (1) where L _{1 is} the length (m of the band-shaped foamed resin impregnated with the slurry liquid before corrugation) ) L ₂ : The length of the band-shaped foamed resin impregnated and coated with the slurry liquid after corrugation (the length m in the primary direction without considering the corrugation).

The method for producing the porous metal body of the present invention will be described. In the present invention, as the band-shaped foamed resin, for example, width: 340 m
m, thickness: band-shaped urethane foam having a thickness of 3 mm can be used. A slurry liquid containing metal powder is impregnated and applied to the band-shaped foamed resin, and the slurry liquid is adhered to the resin column forming the pores of the foamed resin.

As the particle size of the metal powder used in the present invention, the average particle size is 1 to 15 μm and the minimum particle size is 0.1.
It is preferable that the particle size is μm and the maximum particle size is 30 μm. If the average particle size is less than 1 μm, or the minimum particle size is 0.1
When it is smaller than μm, it is difficult to maintain the uniformity of the slurry liquid because the particles are aggregated when the slurry liquid is formed, and when the slurry liquid is applied to the foamed resin, the slurry liquid is applied to the foamed resin with a uniform thickness. It's hard to do. The average particle size is 15 μm
Metallic powders with a super grain size or a maximum grain size of more than 30 μm do not have sufficient sinterability during firing.

Further, in the present invention, when a slurry liquid is prepared, for example, a thermosetting phenol resin can be used as a binder. The slurry liquid prepared from the metal powder and the binder preferably has a viscosity of 50 to 1000 cp. When the viscosity is 50 cp or less, the amount of the slurry adhering to the columns forming the voids of the foamed resin is small, and the strength of the porous metal after firing becomes low. When the viscosity is 1000 cp or more, it becomes difficult to uniformly attach the metal powder to the foamed resin, and it becomes difficult to control the weight of the porous metal formed by firing.

In the present invention, a transverse wave having a corrugation rate of 14 to 30% is formed on a foamed resin impregnated with a slurry liquid. This corrugation can be formed by the corrugating device described below or by another device. FIG. 1 is an explanatory view of the shape of a porous metal continuum 1 during firing of the present invention in a firing furnace 5. In the zone (A) near the entrance of the firing furnace, the height of the wave is large because the progress of firing is small and the shrinkage is small. Although the shrinkage is large in the zone (B) where the firing has progressed, this shrinkage is absorbed by the decrease of the wave height. In the vicinity zone (C) on the outlet side of the firing furnace, firing further progresses and shrinkage further progresses, but this shrinkage is absorbed by the disappearance of the wave height.

As will be described later in Examples, according to the knowledge of the present inventor, if the corrugation rate is less than 14%, fracture occurs in the continuous porous metal body after firing. Further, a corrugation rate of 30% is sufficient, and if the corrugation rate exceeds 30%, a corrugated residue is generated in the porous metal body after firing. Note Within corrugation ratio is 14% to 30% as described later in examples, approximately the length L ₃ of the obtained length L ₂ after corrugation of the belt-like foamed porous resin metal continuum equal. Therefore, by keeping the corrugation rate within this range,
The contraction amount in the length direction of the porous metal continuum during firing is mainly due to the flatness of the corrugation, and further, the contraction amount in the width direction and the thickness direction of the porous metal continuum during firing changes accordingly. It is considered that a porous metal body having a length of about L ₂ after being burned is obtained by being absorbed.

Next, a corrugating apparatus of the present invention for forming a transverse wave on a band-shaped foamed resin impregnated with a slurry liquid containing a metal powder will be described. FIG. 2 is an explanatory view of a side surface of the corrugating device according to claim 2 of the present invention, and FIG. 3 is an explanatory view of the action of the pressing roller of FIG. The corrugating device of FIG.
A wave-shaped roller 2 provided with a gear-shaped wave on the outer surface and rotating in the direction of arrow 10 and a band-shaped foamed resin 1 impregnated with a slurry liquid containing a metal powder are applied along the wave-shaped irregularities of the wave-shaped roller 2. Pressing roller 1 or multiple pressing rollers 3
And a heater 4 for heating the band-shaped foamed resin pressed against the corrugated roller 2.

When the band-shaped foamed resin 1 impregnated with the slurry liquid containing the metal powder is heated by the heater 4 while being pressed against the corrugated roller, the water content in the slurry is further reduced and the slurry is further reduced. The viscosity of the binder component in the inside increases, and a wave habit corresponding to the wave shape of the wave roller 2 is formed. The strip-shaped foamed resin on which the transverse wave is formed is then separated from the corrugated roller 2 and placed on the conveyer conveyor 6 running in the firing furnace 5 shown in FIG. It

In FIG. 3, the pressing rollers 3-1 and 3-2 adjust the pressing force by pressing force adjusting devices 7-1 and 7-2 respectively provided on the pressing rollers 3-1 and 3-2 so that the strip-shaped foamed resin 1 is corrugated.
Press along the corrugated irregularities of. The belt-shaped foamed resin 1 which has not been corrugated is rotated by the corrugated roller 2 in the direction of the arrow 10 so that the corrugated roller 2 and the pressing roller 3 (3-
1, 3-2), it moves in the direction of the arrow and is continuously wavy.

FIG. 4 is an explanatory view of a corrugating device according to claim 3 of the present invention. In this case, the hollow corrugated roller 2-1 is used, and the corrugated roller 2- is used instead of the pressing roller 3 shown in FIG.
The magnet mechanism 8 is arranged inside the hollow portion 1. The band-shaped foamed resin 1 impregnated with a slurry liquid containing a powder of a ferromagnetic metal such as Fe or Ni is attracted because the magnetic force of the magnet mechanism 8 acts on the metal powder, and the corrugated roller 2- It is pressed along the corrugated unevenness of 1. Also in FIG. 4, the strip-shaped foamed resin pressed against the corrugated roller 2-1 is heated by the heater 4 to form a transverse wave in the same manner as described in FIG. It is placed on the conveyor 6 shown in FIG.

FIG. 5 is an explanatory view of a corrugating device according to claim 4 of the present invention. The corrugating device of FIG. 5 includes both the press roller 3 and the magnet mechanism 8. In this corrugating device, the pressing roller 3 is used exclusively in the case of the band-shaped foamed resin impregnated with the slurry liquid containing the non-magnetic metal powder, and the pressing roller 3 is used in the case where the slurry liquid contains the ferromagnetic metal powder. Using the magnet mechanism 8 or the magnet mechanism 8 and the pressing roller 3
Can be used together. Reference numeral 9 in the figure is an example of an air cooling duct, which is used as necessary.

[0017]

EXAMPLE Ni powder having an average particle size of 4 μm, a minimum particle size of 0.4 μm, and a maximum particle size of 10 μm was used as the metal powder, and a phenol-based water-soluble resin was used as the binder.
Powder: 75% by weight, resin: 17.5% by weight, balance: A slurry of water is prepared, a strip-shaped urethane foam having a thickness of 3 mm is impregnated with this slurry, and the urethane foam is dried and then the book shown in FIG. Corrugated using the device of the invention,
Firing was performed in a continuous firing furnace to prepare a continuous body of porous metal. The results are shown in Table 1.

[0018]

[Table 1]

In Table 1, No. 1 to No. 3 are comparative examples having a corrugation rate of less than 14%, but the obtained porous metal continuum was broken. In Table 1, No. 4 to No. 7 are examples of the present invention, but no breakage occurred in the obtained porous metal continuum. In Table 1, No. 8 is a comparative example having a corrugation rate of more than 30%, but the resulting porous metal continuum had no breakage but wavy residue was observed.

[0020]

According to the present invention, a long strip-shaped porous metal can be continuously and efficiently produced without causing breakage due to shrinkage during firing.

[Brief description of drawings]

FIG. 1 is an explanatory view of the shape of a porous metal continuum during firing in a firing furnace.

FIG. 2 is an explanatory diagram of an example of a corrugating device of the present invention.

FIG. 3 is an explanatory view of the action of the pressing roller of the present invention.

FIG. 4 is an explanatory view of another example of the corrugating device of the present invention.

FIG. 5 is an explanatory view of a further different example of the corrugating device of the present invention.

[Explanation of symbols]

1: Band-shaped foamed resin impregnated with a slurry solution containing metal powder, 2 (2-1): corrugated roller, 3 (3-
1, 3-2): presser roller, 4: heating heater,
5: firing furnace, 6: transport table, 7 (7-1, 7-
2): Pressing force adjusting device, 8: Magnet mechanism, 9: Air cooling duct, 10: Rotating direction of corrugated roller.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yoshitaka Akino 1-1-1 Yoshihisa, Takaoka City, Toyama Prefecture

Claims (4)

[Claims] 1. A strip-shaped foamed resin is impregnated with a slurry liquid containing a metal powder, dried, and fired in a firing furnace. Prior to firing, the slurry liquid containing the metal powder is impregnated and applied. A method for producing a porous metal continuum, which comprises forming a transverse wave having a corrugation rate of 14 to 30% represented by the following formula (1) in a band-shaped foamed resin. Corrugation rate = {(L ₁ −L ₂ ) / L ₁ } × 100 (1) where L ₁ : the length (m) L _{2 of} the strip-shaped foamed resin impregnated with the slurry liquid before corrugation: Length (m) of corrugated foamed resin impregnated with slurry liquid after corrugation 2. A rotating corrugated roller provided with a corrugated corrugation on the outer surface thereof, and a strip-shaped foamed resin impregnated with a slurry liquid containing a metal powder are applied along the corrugated irregularities of the corrugated roller. One or more pressing rollers that are pressed against each other, and a slurry containing the metal powder by heating and heating the band-shaped foamed resin impregnated with the slurry liquid containing the metal powder pressed against the corrugated roller A band-shaped foamed resin impregnated with the liquid was provided with a corrugating device consisting of a heater for forming a transverse wave, and a slurry liquid containing a metal powder that passed through the corrugating device and formed a transverse wave was impregnated and coated. An apparatus for producing a continuous porous metal body, which continuously supplies a band-shaped foamed resin to a firing furnace. 3. A hollow rotating corrugated roller provided with a corrugated corrugation on its outer surface, and a strip-shaped roller which is disposed inside the hollow of the corrugated roller and impregnated with a slurry liquid containing a metal powder. The magnet mechanism that attracts the foamed resin and presses it along the corrugated irregularities of the corrugated roller, and the band-shaped foamed resin impregnated with the slurry liquid containing the metal powder pressed against the corrugated roller. A corrugating device comprising a heating heater for forming a transverse wave on a band-shaped foamed resin which is impregnated and coated with a slurry liquid containing metal powder by heating to form a transverse wave is formed by passing the corrugating device. An apparatus for producing a continuous porous metal body, characterized in that a band-shaped foamed resin impregnated with a slurry liquid containing a metal powder is continuously supplied to a firing furnace. 4. An apparatus for producing a continuous porous metal body, wherein the corrugating device has the pressing roller according to claim 2 and the magnet mechanism according to claim 3.