JP2007126753A - High-strength spongy-like sintered metal composite sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-strength spongy-like sintered metal composite sheet and production method thereof. <P>SOLUTION: A high-strength spongy-like sintered metal composite sheet 20 comprising a porous spongy-like sintered metal layer 22 having continuous holes, and a high strength sintered, dense metal reinforcing layer 21 having a porosity smaller than the porosity of the spongy-like sintered metal layer 22, laminated thereon, wherein the sintered, dense metal reinforcing layer 21 has a thickness of 0.5 to 30% thickness with respect to the entire high strength spongy-like sintered metal composite sheet 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a high-strength sponge-like fired metal composite plate. This high-strength sponge-like fired metal composite plate is used for producing a high-temperature filter, an air purifier filter, and an electrode substrate for an alkaline secondary battery. Although used as a material, it is particularly used as a material for producing an electrode substrate of an alkaline secondary battery.

  In general, various filters, electrode substrates of alkaline secondary batteries, and the like have pores (hereinafter referred to as continuous pores) that are open on the surface and continuous with the internal pores, and have a porosity of 70 to 99% by volume. A sponge-like fired metal plate having the following is used. Further, in recent years, an electrode substrate of an alkaline secondary battery or the like is made of a sintered sintered metal having continuous vacancies and ultrafine continuous vacancies (hereinafter referred to as intra-framework vacancies) compared to the continuous vacancies. A sponge-like fired metal plate having a structure composed of a skeleton portion is used. The average pore diameter of the continuous pores is 100 to 700 μm, the average pore diameter of the fine pores in the skeleton of the skeleton is 0.5 to 20 μm, and the porosity is 10 to 55%. The porosity of the entire metal plate is preferably in the range of 90 to 99%.

  In general, an apparatus shown in the cross-sectional explanatory view of FIG. 10 is used to manufacture the sponge-like fired metal plate. In FIG. 10, 6 is a carrier sheet, 7 is a doctor blade, 8 is foamed slurry, 9 is a high-temperature / high-humidity tank, 11 is a drying tank, 12 is a hopper, 13 is an unwinding reel, 14 is a take-up reel, 15, Reference numeral 16 denotes a support roll.

  A surfactant and a foaming agent are added to a slurry composed of raw material powder and thinner to prepare a foamed slurry 8, which is stored in a hopper 12, and this foamed slurry 8 is stored in a carrier sheet 6 as shown in FIG. It is formed into a thin plate shape by a doctor blade 7 and foamed in a sponge shape using the vapor pressure of the volatile organic solvent contained in the foamed slurry and the foaming property of the surfactant in the high temperature / high humidity tank 9. Furthermore, it is dried in a drying tank 11 to produce a sponge-like green plate 10 ', and this sponge-like green plate 10' is degreased and fired by passing it through a degreasing device and a firing furnace (both not shown). A sponge-like fired metal plate having pores is manufactured.

  In order to reinforce a sponge-like fired metal plate made in this way, a metal layer having a normal punching hole, a metal net, or a plurality of thin metal layers is generally resistance-welded on one side of the sponge-like fired metal plate. Then, the reinforcing layer is formed and strengthened by integrating them.

However, when a metal tape having a punching hole, a metal mesh, or the like is integrated with such a sponge-like fired metal plate by resistance welding, a process for producing the sponge-like fired metal plate, a sponge-like fired metal plate, a metal tape, and a metal mesh are obtained. It is not preferable because it requires at least two steps of resistance welding, etc., and is expensive to manufacture. Also, when a metal tape, metal mesh, etc. are resistance-welded to a sponge-like fired metal plate, a sponge-like fired metal is used with an electrode roll. There were problems such as crushing the pores of the plate, thereby reducing the porosity of the sponge-like fired metal plate.
Further, the foamed slurry is formed into a thin plate shape by a doctor blade method on a metal tape having a punching hole, a metal net, etc., and the vapor pressure of the volatile organic solvent contained in the foamed slurry in a high temperature / high humidity tank A metal tape having punched holes by forming a sponge-like green plate having continuous pores by foaming into a sponge shape utilizing the foaming property of the surfactant, and degreasing and firing the sponge-like green plate, A method for producing a high-strength sponge-like fired metal composite plate by laminating a sponge-like fired metal plate having continuous pores on a metal net or the like is also conceivable, but the high-strength sponge-like fired metal produced by this method is also conceivable. The composite plate is because the shrinkage rate of the sponge-like green plate during degreasing and firing is much larger than the shrinkage rate of the metal tape or metal mesh. Or curved in the side of the sponge-like fired metal layer, cracking there is a problem such as may occur spongy sintered metal layer.
Further, when used as an electrode substrate of an alkaline secondary battery, the sponge is fired by impregnating the active material into the sponge-like fired metal layer of the high-strength sponge-like fired metal composite plate and rolling using a rolling roll. And the metal tape are not sufficiently bonded, and the sponge-like fired metal layer and the metal tape may peel off.

Then, as a result of conducting research to solve such a problem, the present inventors,
(A) A slurry consisting of a mixture of raw material powder and thinner or a mixture of raw material powder, thinner and surfactant is spread on a carrier sheet by the doctor blade method and heated. A green layer for forming a fired metal dense reinforcing layer (hereinafter referred to as a dense reinforcing green layer) is formed by drying, and on one side of the dense reinforcing green layer, raw material powder, thinner, surfactant and foam A slurry prepared by adding an agent (hereinafter referred to as a foamed slurry) is extended by a doctor blade method and heated. A composite green comprising a dense reinforced green layer and a sponge-like green layer by drying and forming a green layer (hereinafter referred to as a sponge-like green layer) for forming a sponge-like fired metal layer on the densely reinforced green layer. A high porosity porcelain fired metal layer having continuous pores (hereinafter referred to as continuous pores) that are open on the surface and continuous with the internal pores when the composite green plate is prepared and degreased and fired. Further, a high-strength sponge-like fired metal composite plate in which a fired metal dense reinforcing layer having a porosity smaller than that of the sponge-like fired metal layer and denser and higher in strength than the sponge-like fired metal layer is laminated. This sponge-like fired metal composite board is not degreased and fired during the degreasing and firing process, and the sponge-like fired metal layer is not cracked. Spongy sintered metal composite plate of high strength can be obtained with a high porosity, there is no further separation of the time of electrode substrates prepared of an alkaline secondary battery is produced,
(B) The thickness of the fired metal dense reinforcing layer preferably has 0.5 to 30% (preferably 1 to 5%) of the total thickness of the high-strength sponge-like fired metal composite plate.
(C) The fired metal dense reinforcing layer has continuous pores that are finer than the continuous pores of the sponge-like fired metal layer that are open on the surface and are continuous with the internal pores (hereinafter referred to as continuous fine pores). And having a porosity smaller than that of the sponge-like fired metal layer, it has high strength and high electrical conductivity. However, the porosity of the fired metal dense reinforcing layer is 4 to 55% by volume (more preferably Is preferably 20 to 40% by volume),
(D) By providing punched holes or the like in the fired metal dense reinforcing layer, a denser fired metal dense reinforcing layer having a porosity of less than 4% by volume can be formed, and the porosity without voids: 0% by volume The fired metal dense reinforcing layer can be formed with a porosity of less than 4% by volume or without any voids, and even if the fired metal dense reinforcing layer is laminated with the sponge-like fired metal layer by firing, the shrinkage rate during firing is There was no significant difference from the shrinkage ratio during firing of the sponge-like fired metal layer, and the inventors obtained knowledge that the sponge-like fired metal layer was not bent or cracked.

This invention has been made based on such knowledge,
(1) A slurry containing no foaming agent is used on one side of a highly porous sponge-like fired metal layer having continuous pores formed using a slurry containing a foaming agent and having a porosity of 70 to 99% by volume. High-strength sponge-like fired metal composite plate obtained by laminating a high-strength fired metal dense reinforcing layer having a porosity of 0 to 55 (including 0) volume% smaller than the porosity of the sponge-like fired metal layer formed And the thickness of the fired metal dense reinforcing layer is 0.5-30% of the total thickness of the high strength sponge-like fired metal composite plate,
(2) A slurry containing no foaming agent is used on one side of a highly porous sponge-like fired metal layer having continuous pores formed using a slurry containing a foaming agent and having a porosity of 70 to 99% by volume. High-strength sponge-like fired layered with a high-strength fired metal dense reinforcing layer having continuous fine pores formed and having a porosity smaller than the porosity of the sponge-like fired metal layer: 4 to 55% by volume A high-strength sponge-like fired metal composite plate, wherein the thickness of the fired metal dense reinforcing layer is 0.5-30% of the total thickness of the high-strength sponge-like fired metal composite plate,
(3) A slurry containing no foaming agent is used on one side of a highly porous sponge-like fired metal layer having continuous pores formed using a slurry containing a foaming agent and having a porosity of 70 to 99% by volume. Porosity formed by: a high-strength sponge-like fired metal composite plate formed by laminating a high-strength fired metal dense reinforcing layer having a porosity of less than 4% by volume or no voids, and the thickness of the fired metal dense reinforcing layer Is characterized by a high-strength sponge-like fired metal composite plate having a thickness of 0.5-30% of the total thickness of the high-strength sponge-like fired metal composite plate.

  A high strength sponge-like fired metal composite plate having a fired metal dense reinforcing layer for imparting strength can be provided on one side or inside of a sponge-like fired metal layer having a high porosity. The plate can be used as a material for producing various filters and electrode substrates for alkaline secondary batteries, and the electrode substrate for alkaline secondary batteries obtained using this high-strength sponge-like sintered metal composite plate has been conventionally used. Since the average packing density of the active material is increased, the resistance is low, and the current collection efficiency can be improved, it can greatly contribute to the development of the alkaline secondary battery industry.

The reasons for limiting the numerical values of the present invention are as follows.
If the thickness of the fired metal dense reinforcing layer is less than 0.5%, the thickness of the fired metal dense reinforcing layer is too thin to obtain sufficient strength, while the thickness of the fired metal dense reinforcing layer exceeds 30%. Even when sufficient strength is obtained, it is not preferable because the active material cannot be sufficiently filled when used as an electrode substrate of an alkaline secondary battery. Therefore, the thickness of the fired metal dense reinforcing layer of the present invention is set to 0.5 to 30% (preferably 1 to 5%) of the total thickness of the high-strength sponge-like fired metal composite plate.
The high porosity sponge-like fired metal layer having continuous pores constituting the high-strength sponge-like fired metal composite plate of the present invention has a porosity of 70 to 99% by volume. The high porosity sponge-like fired metal layer having the same porosity as the metal layer has continuous pores having an average pore diameter of 100 to 700 μm. Furthermore, the high porosity sponge-like fired metal layer having the continuous pores is composed of continuous pores having an average pore diameter of 100 to 700 μm and a skeleton having an average pore diameter of 0.5 to 20 μm shown in the column of the prior art. It may be a sponge-like fired metal layer having a porosity of 10 to 55% by volume having fine pores and an overall porosity of 70 to 99% by volume.

The high-strength sponge-like fired metal composite plate in which the high-strength fired metal dense reinforcing layer of the present invention is laminated will be described in more detail with reference to the drawings.
FIG. 1 is a diagram showing a high-strength high-strength fired metal dense reinforcing layer 21 having a porosity of 4 to 55% by volume and a high-porosity sponge-like fired metal layer 22 having continuous pores 1 laminated on one side. 2 is a cross-sectional enlarged model view of a sponge-like fired metal composite plate 20. FIG.
The sponge-like fired metal layer 22 is generally composed of the continuous pores 1 and the skeleton part 23, and has a porosity of 70 to 99%, which is a generally known value. When a high-strength fired metal dense reinforcing layer having a porosity of 4 to 55% by volume is laminated on one side of the sponge-like fired metal layer 22, the sponge-like fired metal layer 22 is placed on one side of the fired metal dense reinforcing layer 21. Laminate. Each of the high-strength sponge-like fired metal composite plates 20 of the present invention composed of the fired metal dense reinforcing layer 21 and the known sponge-like fired metal layer 22 shown in FIG. Is 0.5 to 30% of the total thickness of the high-strength sponge-like fired metal composite plate 20.

  FIG. 2 shows the high strength of the present invention, in which a high-strength fired metal dense reinforcing layer 21 having a porosity of 4 to 55% by volume is laminated with a high-porosity sponge-like fired metal layer 32 having continuous pores 1 on one side. 2 is a cross-sectional enlarged model view of a sponge-like fired metal composite plate 20. FIG.

  In FIG. 2, a high-porosity sponge-like fired metal layer 32 having continuous pores 1 laminated on one side of a fired metal dense reinforcing layer 21 is composed of continuous pores 1 and a skeleton portion 33. Inner fine pores 34 are included, and the overall porosity thereof is 70 to 99%. The average pore diameter of the continuous pores 1 is 100 to 700 μm, the average pore diameter of the fine pores 34 in the framework of the framework portion 33 is 0.5 to 20 μm, and the porosity is 10 to 55%. The porosity of the entire fired metal layer 32 is 70 to 98%. This high-porosity sponge-like fired metal layer is already generally known. The high-strength sponge-like fired metal composite plate 20 of the present invention composed of the fired metal dense reinforcing layer 21 and the known sponge-like fired metal layer 22 shown in FIG. Has a thickness of 0.5 to 30% of the total thickness of the high-strength sponge-like fired metal composite plate 20. Moreover, it is preferable that the average hole diameter of the high intensity | strength baked metal dense reinforcement layer 21 which has porosity: 4-55 volume% exists in the range of 1-100 micrometers.

  In order to manufacture the high-strength sponge-like fired metal composite plate 20 of the present invention shown in FIGS. 1 to 2, first, as shown in the cross-sectional explanatory view of FIG. The foamed slurry 8 is supplied on the sheet 6 and supplied to the carrier sheet 6 on which the densely reinforced green tape 17 is placed. In a high-temperature / high-humidity tank 9, the foamed slurry 8 is foamed using a vapor pressure of the volatile organic solvent contained in the foamed slurry 8 and a foaming property of the surfactant, and further in the drying tank 11. A composite green plate 10 composed of a densely reinforced green layer and a sponge-like green layer is produced by drying, and this composite green plate 10 is removed from a degreasing apparatus and a firing furnace (both are Degreasing by passing Shimese not) fired to produce a high strength spongy sintered metal composite plate 20 of the present invention.

  In FIG. 3, 7 is a doctor blade, 9 is a high temperature / high humidity tank, 11 is a drying tank, 12 is a hopper, 13 is a take-up reel, 14 is a take-up reel, and 15 and 16 are support rolls. Since this is the same as FIG. The composite green plate composed of the densely reinforced green layer and the sponge-like green layer is degreased and fired to obtain a sponge-like fired metal layer 22 shown in FIGS. 1 and 2 and a high strength having a porosity of 4 to 55% by volume. The high-strength sponge-like fired metal composite plate 20 of the present invention comprising the fired metal dense reinforcing layer 21 can be produced.

  In FIG. 3, the densely reinforced green tape 17 prepared in advance is supplied. As shown in the cross-sectional explanatory view of FIG. 4, the dense reinforcing layer forming slurry 19 stored in the hopper 12 is placed on the carrier sheet 6. The dense reinforcing slurry layer 24 is formed on the carrier sheet 6 by thinly extending the dense reinforcing layer forming slurry 19 with the doctor blade 7 ′, and this dense reinforcing slurry layer 24 is placed in the high temperature / high humidity tank 9 ′. The foamed slurry layer is formed while supplying the foamed slurry 8 onto the dense reinforcing slurry layer 24 whose surface has been lightened green by passing the surface lightly green, and subsequently the high temperature / high humidity tank 9 and dried. A composite green plate 10 composed of a densely reinforced green layer and a sponge-like green layer is produced by passing through a tank 11, and this composite group The lean plate can be degreased and fired by passing it through a degreasing device and a firing furnace (both not shown) to produce the high-strength sponge-like fired metal composite plate 20 of the present invention shown in FIGS. 1 and 2. .

The reason why the high-temperature / high-humidity tank 9 'is provided is to make the surface of the dense reinforcing slurry layer 24 light green so that the dense reinforcing layer forming slurry 19 and the foaming slurry 8 are not mixed when producing a composite green plate. belongs to.

  Further, the present invention is characterized by a high-strength sponge-like fired metal composite plate in which a high-strength fired metal dense reinforcing layer having a porosity of less than 4% by volume or no voids is laminated. Porosity: Less than 4% by volume or high-strength fired metal dense reinforcing layer having no voids is not sufficiently air permeable, so fired metal dense reinforcing layer provided with a plurality of punching holes, net-like fired metal dense reinforcing layer Further, it is necessary to stack a fired metal dense reinforcing layer or the like arranged in parallel at intervals.

  A high-strength sponge-like fired metal composite plate in which a high-strength fired metal dense reinforcing layer having a porosity of less than 4% by volume or having no voids is laminated will be described in detail with reference to the drawings.

  FIG. 5 is an explanatory plan view of a high-strength sponge-like fired metal composite plate 20 in which a high-strength fired metal dense reinforcing layer having a porosity of less than 4% by volume or having no voids is laminated, and FIG. FIG. 6 is a cross-sectional view taken along the line II of FIG. 5 and 6, 1 is a continuous pore, 2 is a porosity: less than 4% by volume, or a high-strength sintered metal dense reinforcing layer having no void. As shown in FIGS. 5 and 6, the high-strength sponge-like fired metal composite plate 20 having the fired metal dense reinforcing layer 2 is disposed on one side of the sponge-like fired metal layer 22 and in the longitudinal direction of the sponge-like fired metal layer 22. A high-strength sponge-like fired metal composite plate 20 having the fired metal dense reinforcing layer 2 shown in FIGS. 5 and 6 is formed with a narrow and narrow strip-like fired metal dense reinforcing layer 2 in parallel. It can be cut into a predetermined shape and used as it is as a high temperature filter or an air purifier filter.

  Moreover, as shown in FIG. 7, the high-strength sponge-like fired metal composite plate 20 shown in FIGS. 5 and 6 is paired with a part having the fired metal dense reinforcing layer 2 and a part having the continuous pores 1. It can cut | disconnect in this way and the electrode substrate 3 of an alkaline secondary battery can be manufactured. As shown in FIG. 7, there is a fired metal dense reinforcing layer 2, and even if the current collecting tab 4 is welded 5 to the fired metal dense reinforcing layer 2, the continuous pores 1 are not crushed. The proportion of the holes 1 does not decrease, and the amount of the active material contained in the entire electrode is not decreased by welding the current collecting tab.

  The fired metal dense reinforcing layer 2 formed on one side of the high-strength sponge-like fired metal composite plate 20 of the present invention has a narrow band-like fired metal dense reinforcing layer 2 spaced in parallel with the length direction in FIG. However, it may be a lattice shape or a net shape (not shown), or any other shape, and is particularly limited to the shapes shown in FIGS. is not.

  For example, a high-strength wide-width dense reinforcing green tape 17 having punching holes 18 shown in FIG. 8 is prepared in advance, and the dense reinforcing green tape 17 having punching holes 18 is shown in the cross-sectional explanatory view of FIG. The foamed slurry is supplied to be placed on the carrier sheet 6, and the foamed slurry is applied onto the dense reinforced green tape 17 having the punching holes 18 while supplying the foamed slurry 8 onto the dense reinforced green tape 17 having the punched holes 18. 8 is formed into a thin plate shape, foamed into a sponge shape using the vapor pressure of the volatile organic solvent contained in the foamed slurry 8 and the foamability of the surfactant, and then dried to form a densely reinforced green layer and A composite green plate made of a sponge-like green layer was produced, and this composite green plate was degreased and a firing furnace (both not shown). Finely baked metal having continuous pores 1 and provided with punching holes 18 on one side as shown in the plan view of FIG. 9A and the cross-sectional view of FIG. 9B. The high-strength sponge-like fired metal composite plate 20 of the present invention having the reinforcing layer 2 can be manufactured. As shown in the plan view of FIG. 9A and the cross-sectional view of FIG. 9B, the high-strength sponge-like fired metal composite plate 20 obtained in this way has continuous pores 1 with a high-strength sponge-like shape. The back surface of the fired metal composite plate 20 has a structure exposed from the punching hole 18 of the fired metal dense reinforcing layer 2.

  As shown in FIGS. 3 and 4, the high-strength sponge-like fired metal composite plate of the present invention is a mixture of raw material powder (filler) and thinner or a mixture of raw material powder (filler), thinner and surfactant. The body slurry is spread on a carrier sheet by the doctor blade method and heated. A dense reinforced green layer for forming a fired metal dense reinforcing layer was formed by drying, and a raw material powder (filler), a thinner, a surfactant and a foaming agent were added on the dense reinforced green layer. The foamed slurry is extended by the doctor blade method and heated. A composite green plate comprising a densely reinforced green layer and a sponge-like green layer is prepared by drying and forming a sponge-like green layer on the densely reinforced green layer to form a sponge-like fired metal layer. It can be produced by degreasing and firing the green plate.

  The high-strength sponge-like fired metal composite plate according to the above (1) to (3) can be used as a material for producing a high-temperature filter, an air cleaner filter, and an alkaline secondary battery electrode substrate. It is particularly preferable to prepare an electrode substrate for an alkaline secondary battery.

Therefore, the present invention
(4) The electrode substrate of an alkaline secondary battery produced using the high-strength sponge-like fired metal composite plate described in (1) to (3) is characterized.

  The raw material powder for producing the high-strength sponge-like fired metal composite plate of the present invention is preferably Ni powder, Ni-base alloy powder, Cu powder, Cu-base alloy powder, Fe powder or Fe-base alloy powder. However, other metal powders may be used, and the present invention is not limited thereto.

Example 1
Fillers and thinners were blended with the composition shown in Table 1, and kneaded in a sealed container for 4 hours to prepare a dense reinforcing layer forming slurry, which was stored in a hopper 12 'shown in FIG.
Next, the filler and thinner were blended with the blending composition shown in Table 2, kneaded in a closed container for 24 hours, the amount of surfactant shown in Table 2 was added, and the mixture was kneaded for 15 minutes under reduced pressure. The amount of foaming agent shown in Table 2 was added and kneaded for 5 minutes under atmospheric pressure to prepare foamed slurry, and the resulting foamed slurry was stored in the hopper 12 shown in FIG.

  First, a dense reinforcing layer forming slurry 19 shown in Table 1 is formed on the carrier sheet 6 of FIG. 4 with a blade gap of 0.1 mm, and this slurry layer is passed through a high temperature / high humidity tank 9 ′. After the surface is lightly dried by drying at 30 ° C. for 2 minutes, this is supplied under the hopper 12 storing the foamed slurry 8 shown in Table 2, and the foamed slurry 8 is applied with a blade gap of 0.4 mm. A laminated slurry is prepared by the above, and this laminated slurry is supplied to the high-temperature / high-humidity tank 9 shown in FIG. Then, it was dried with warm air under the condition of holding for 15 minutes to produce a composite green plate 10 composed of a densely reinforced green layer and a sponge-like green layer.

While passing this composite green plate through a degreasing device (not shown), degreasing was performed under the condition of holding at an air temperature of 500 ° C. for 15 minutes, and subsequently passing through a firing furnace (not shown), N ₂ in -5% H ₂ atmosphere, consisting of spongy sintered metal layer and sintering the metal dense reinforcing layer shown in Table 3 by firing under the conditions shown in Table 3 high strength spongy sintered metal composite board of the present invention ( (Hereinafter referred to as composite plates of the present invention) 1 to 3 were produced.

  The composite plates 1 to 3 of the present invention thus obtained were partially embedded in a resin, the cross-section was polished, and observed with an optical microscope at a magnification of 100 times to obtain a sponge-like fired metal layer and fired metal dense reinforcement. The porosity of the layer and the ratio of these thicknesses were measured, and the presence or absence of bending and the presence or absence of cracks in the spongy fired metal layer were observed. The results are shown in Table 3. Furthermore, it was cut into a JISZ2201 (metal material tensile test piece) No. 13A shape with an electric discharge machine, a tensile test was performed, and further, it was cut into a width of 10 mm and a length of 200 mm, and the specific resistance was measured by a four-terminal method. Are shown in Table 3.

  Furthermore, 1% by weight of carboxymethylcellulose (CMC), 3% by weight of polytetrafluoroethylene (PTFE) and 30% by weight of pure water based on a mixed powder consisting of 92% by weight of nickel hydroxide powder and 8% by weight of cobalt monoxide powder. % And then kneading to produce a paste-like active material, impregnating the active material into the composite plates 1 to 3 of the present invention, drying at a temperature of 100 ° C. for 3 hours, and further using a rolling roll Rolled 30% and observed the cross sections of the composite plates 1-3 of the present invention after rolling with an optical microscope to observe the presence or absence of peeling between the sponge-like fired metal layer and the fired metal dense reinforcing layer. The results are shown in Table 3. It was.

Conventional Example 1
Thickness provided with punching holes: Ni thin plate provided with punching holes under the same conditions as in Example 1 by applying the foaming slurry shown in Table 2 of Example 1 to the surface of the Ni thin plate of 60 μm by the doctor blade method. A conventional composite plate 1 having a sponge-like fired metal layer formed on its surface was prepared. The obtained conventional composite plate 1 was subjected to the same measurements and observations as in Example 1, and the results are shown in Table 3.

Conventional example 2
A sponge-like fired metal plate having no dense reinforcing layer was prepared from the foamed slurry shown in Table 2 of Example 1 by the doctor blade method, and the same measurement and observation as in Example 1 were performed on the obtained plate. Are shown in Table 3.

  From the results shown in Table 3, it can be seen that any of the composite plates 1 to 3 of the present invention can be used as a material for producing a high-temperature filter, an air purifier filter, and an alkaline secondary battery electrode substrate. However, the conventional composite plate 1 is bent to the sponge-like fired metal layer side, and when this is attempted to be corrected, cracks are generated in the sponge-like fired metal layer, such as high temperature filters, air purifier filters, alkaline secondary batteries. It could not be used as a material for producing the electrode substrate. In addition, the sponge-like fired metal plate of Conventional Example 2 has a low strength, cannot be used as an air purifier filter for a high-temperature filter, and has a large specific resistance, so that it has good results as an electrode plate for an alkaline secondary battery. It was not obtained.

Example 2
In the composition shown in Table 4, a thinner was first prepared, a filler was blended therein, kneaded in a sealed container for 8 hours to form a slurry, molded by a known doctor blade method, naturally dried, and then made into a width of 4 mm. A long, densely reinforced green tape having slits of 0.1 mm thickness and 4 mm width and a porosity of 0% was produced.

  Next, in the blending composition shown in Table 5, first, the filler and the thinner were kneaded for 24 hours, then the surfactant was added and kneaded for 15 minutes under reduced pressure, and then the foaming agent was added and the pressure was reduced to 5 at atmospheric pressure. Kneading was carried out to prepare a foamed slurry.

  As shown in FIG. 3, the densely reinforced green tape is supplied on a carrier sheet at an interval of 6 cm, and the foamed slurry is placed on the carrier sheet on which the densely reinforced green tape is placed, with a blade gap of 0.4 mm. Vapor of volatile organic solvent contained in foamed slurry under conditions of feed rate: 0.4 mm / min by doctor blade method, then temperature: 40 ° C., humidity: 90%, holding for 20 minutes The foam is foamed into a sponge using the pressure and the foaming property of the surfactant, and then dried under warm air, at a temperature of 80 ° C. for 15 minutes, and is densely reinforced green tape and a sponge-like green layer on one side A composite green plate made of

While passing this composite green plate through a degreasing device (not shown), degreasing is performed in air at a temperature of 600 ° C. for 30 minutes, and then N is passed through a firing furnace (not shown). _The composite plate 4 of the present invention having a fired metal dense reinforcing layer was produced by firing under the conditions of 2-5% H ₂ , temperature: 1100 ° C., and holding for 30 minutes. The composite plate 4 of the present invention was cut into a JISZ2201 (metal material tensile test piece) 13A shape by an electric discharge machine to produce a tensile test piece having a sintered metal dense reinforcing layer. Further, tensile test pieces having no fired metal dense reinforcing layer were prepared, and tensile tests were performed using these tensile test pieces. The results are shown in Table 6.

  From the results shown in Table 6, it can be seen that the tensile strength of the sponge-like porous metal plate is remarkably improved by providing the sintered metal dense reinforcing layer.

Example 3
Next, the composite plate 4 of the present invention obtained in Example 2 was cut with an electric discharge machine to produce an electrode substrate of the alkaline secondary battery of the present invention having a fired metal dense reinforcing layer having the structure shown in FIG. After filling the electrode substrate of the obtained alkaline secondary battery of the present invention with an active material mainly composed of nickel hydroxide, the whole average active material including a sintered metal dense reinforcing layer is rolled and pressed at a reduction ratio of 50%. The packing density was measured and the results are shown in Table 7.

  Furthermore, for comparison, a sponge-like green plate was produced from the foamed slurry shown in Table 5 under the same conditions as in Example 2 using the apparatus shown in FIG. A sponge-like porous metal plate was produced by degreasing under conditions and subsequently firing under the same conditions as in Example 2. Nickel tape is joined to this sponge-like porous metal plate by resistance welding, and the sponge-like porous metal plate joined with this nickel tape is cut with an electric discharge machine to produce an electrode substrate for a conventional alkaline secondary battery, The electrode substrate of the obtained conventional alkaline secondary battery is filled with an active material mainly composed of nickel hydroxide, and is rolled and pressed at a reduction ratio of 50%, and the total average active material filling density including the nickel tape joint is determined. Table 7 shows the measurement results.

  As is apparent from the results shown in Table 7, the electrode substrate of the alkaline secondary battery of the present invention produced using the sponge-like porous metal plate produced by the method of the present invention is a conventional alkaline secondary battery electrode substrate. It can be seen that the average active material packing density can be increased by 4%.

Example 4
Dense reinforcing layer forming slurries A to E having the compositions shown in Table 8 and foaming slurries A to E having the compositions shown in Table 9 were prepared.

  The dense reinforcing layer forming slurry A shown in Table 8 is stored in the hopper 12 ', and the foamed slurry A shown in Table 9 is further stored in the hopper 12, and the dense reinforcing layer forming slurry A is placed on the carrier sheet 6 shown in FIG. A dense reinforcing slurry layer 24 is formed with a thickness of 2 mm, and this slurry layer is passed through a high-temperature / high-humidity tank 9 ′ and dried at 30 ° C. for 2 minutes to lightly dry the surface. Is supplied under the hopper 12 for storing the slurry, and a slurry slurry is prepared by coating the foaming slurry 8 with a blade gap of 0.5 mm, and this slurry slurry is supplied to the high temperature / high humidity tank 9 of FIG. After foaming under the conditions of temperature: 40 ° C., humidity: 90%, holding for 20 minutes, hot air drying is performed under the conditions of temperature: 80 ° C., holding for 15 minutes, and the densely reinforced green layer and spot A composite green plate composed of a green-like green layer was produced.

This composite green plate is degreased under the conditions shown in Table 10 while passing through a degreasing apparatus (not shown), and then fired under the conditions shown in Table 10 while passing through a firing furnace (not shown). By doing this, this invention composite board 5 which consists of a sponge-like baking metal layer and baking metal dense reinforcement layer which are shown in Table 11 was produced.
For the composite plate 5 of the present invention thus obtained, the porosity of the sponge-like fired metal layer and the fired metal dense reinforcing layer, the ratio of these thicknesses, the presence or absence of bending, and the sponge-like fired, as in Example 1. It was observed whether or not the metal layer was cracked, and the results are shown in Table 11.

  Dense reinforcing layer forming slurry B in Table 8 and Foaming slurry B in Table 9, dense reinforcing layer forming slurry C in Table 8, foaming slurry C in Table 9, dense reinforcing layer forming slurry D in Table 8 and foaming slurry D in Table 9 For the dense reinforcing layer forming slurry E shown in Table 8 and the foaming slurry E shown in Table 9, composite green plates were prepared in the same manner as the dense reinforcing layer forming slurry A shown in Table 8 and the foaming slurry A shown in Table 9. By degreasing the plate under the conditions shown in Table 10 while passing through the degreasing device (not shown), and then firing under the conditions shown in Table 10 while passing through the firing furnace (not shown). The composite plates 5 to 9 of the present invention comprising the sponge-like fired metal layer and the fired metal dense reinforcing layer shown in Table 11 were produced.

  With respect to the composite plates 5 to 9 of the present invention thus obtained, the presence or absence of bending and the presence or absence of cracks in the sponge-like fired metal layer were observed in the same manner as in Example 1, and the results are shown in Table 11. It was shown to.

  From the results shown in Table 11, the composite plates 5 to 9 of the present invention produced by the method of the present invention are not bent, and further, no cracks are generated in the sponge-like fired metal layer. It turns out that it can use as a raw material for producing the filter for air cleaners.

It is a cross-sectional enlarged model view of a high-strength sponge-like fired metal composite plate. It is a cross-sectional enlarged model view of a high-strength sponge-like fired metal composite plate. It is sectional explanatory drawing of the apparatus for manufacturing the composite green board which has a dense reinforcement green layer used for manufacture of the high intensity | strength sponge-like baking metal composite board of this invention. It is sectional explanatory drawing of the apparatus for manufacturing the composite green board which has a dense reinforcement green layer used for manufacture of the high intensity | strength sponge-like baking metal composite board of this invention. 1 is a schematic plan view of a high-strength sponge-like fired metal composite plate of the present invention. It is II sectional drawing of FIG. It is a top view of the electrode substrate of the alkaline secondary battery produced using the high intensity | strength sponge-like baking metal composite board of this invention. It is a top view of the dense reinforcement green tape which has a punching hole. 1 is a schematic plan view of a high-strength sponge-like fired metal composite plate of the present invention having a fired metal dense reinforcing layer provided with punching holes. It is sectional explanatory drawing of the apparatus for manufacturing the composite green board used for manufacture of the conventional sponge-like porous metal plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Continuous void | hole 2 Baking metal dense reinforcement layer 3 Electrode board | substrate of an alkaline secondary battery 4 Tab 5 Welding 6 Carrier sheet 7 Doctor blade 8 Foaming slurry 9 High temperature, high humidity tank 10 Composite green board 11 Drying tank 12 Hopper 12 'Hopper 13 Unwinding reel 14 Take-up reel 15 Support roll 16 Support roll 17 Dense reinforcing green tape 18 Punching holes 19 Dense reinforcing layer forming slurry 20 High-strength sponge-like porous metal composite plate 21 Baking metal dense reinforcing layer 22 Sponge-like baking metal layer 23 Skeletal portion 24 Dense reinforcing slurry layer 32 Sponge-like fired metal layer 33 Skeletal portion 34 Fine pores in the skeleton

Claims (9)

High porosity having 70 to 99% by volume of pores having continuous pores (hereinafter referred to as continuous pores) open to the surface formed using a slurry containing a foaming agent and continuing to the internal pores High-strength having a porosity of 0 to 55 (including 0) volume% smaller than the porosity of the sponge-like fired metal layer formed on one side of the sponge-like fired metal layer using a slurry containing no foaming agent It is a high-strength sponge-like fired metal composite plate formed by laminating a fired metal dense reinforcing layer, and the thickness of the fired metal dense reinforcing layer is 0.5-30 of the total thickness of the high-strength sponge-like fired metal composite plate. % High-strength sponge-like fired metal composite plate characterized by having a thickness of%. It was formed using a slurry containing no foaming agent on one side of a high porosity sponge-like fired metal layer having continuous pores formed using a slurry containing a foaming agent and having a porosity of 70 to 99% by volume. A porosity that is smaller than the porosity of the sponge-like fired metal layer and that has fine pores that are finer than the continuous pores of the sponge-like fired metal layer that opens to the surface and continues to the internal pores: 4 A high-strength sponge-like fired metal composite plate obtained by laminating a high-strength fired metal dense reinforcing layer having a volume of ~ 55% by volume, and the thickness of the fired metal dense reinforcing layer is the entire high-strength sponge-like fired metal composite plate A high-strength sponge-like fired metal composite plate characterized by having a thickness of 0.5 to 30% of the thickness. It was formed using a slurry containing no foaming agent on one side of a high porosity sponge-like fired metal layer having continuous pores formed using a slurry containing a foaming agent and having a porosity of 70 to 99% by volume. Porosity: A high-strength sponge-like fired metal composite plate formed by laminating a high-strength fired metal dense reinforcing layer having a porosity of less than 4% by volume or having no voids, and the fired metal dense reinforcing layer has a high strength. A high-strength sponge-like fired metal composite plate characterized by having a thickness of 0.5 to 30% of the total thickness of the sponge-like fired metal composite plate. The high porosity sponge-like fired metal layer having continuous pores has continuous pores having an average pore diameter of 100 to 700 µm and a porosity of 70 to 99 vol%. 2. A high-strength sponge-like fired metal composite plate according to 2 or 3. The high porosity sponge-like fired metal layer having continuous pores has a porosity having an average pore diameter of 100 to 700 μm and pores having a fine pore in the skeleton having an average pore diameter of 0.5 to 20 μm: 10 The high-strength sponge-like fired metal composite plate according to claim 1, 2, 3 or 4, characterized in that the high-strength sponge-like fired metal composite plate is composed of a skeleton part of ~ 55% by volume and has a porosity of 70 to 99% by volume. 6. The sponge-like fired metal layer and the fired metal dense reinforcing layer are both made of fired metal obtained by firing Ni powder or Ni-based alloy powder. High strength sponge-like fired metal composite plate. An electrode substrate of an alkaline secondary battery produced using the high-strength sponge-like fired metal composite plate according to claim 6. Each of the sponge-like fired metal layer and the fired metal dense reinforcing layer is made of a fired metal formed by firing Ni powder, Ni-base alloy powder, Cu powder, Cu-base alloy powder, Fe powder or Fe-base alloy powder. The high-strength sponge-like fired metal composite plate according to claim 1, 2, 3, 4 or 5. A filter produced using the high-strength sponge-like fired metal composite plate according to claim 8.

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