JP2004043976A - High strength spongy baked metal composite plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high strength spongy baked metal composite plate and its producing method. <P>SOLUTION: In the high strength spongy baked metal composite plate 20 laminating a high strength baked metal adhesively reinforced layer 21 having smaller porosity than the porosity of the spongy baked metal layer 22 having continued pores, the baked metal adhesively reinforced layer 21 has the thickness at 0.5-30% of the whole thickness of the high strength spongy baked metal composite plate 20. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a high-strength sponge-like fired metal composite plate, and the high-strength sponge-like fired metal composite plate is used for producing a high-temperature filter, a filter for an air purifier, and an electrode substrate of an alkaline secondary battery. Although it is 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 opened on the surface and connected to internal pores (hereinafter referred to as continuous pores), and porosity: 70 to 99% by volume. Is used. Further, in recent years, an electrode substrate or the like of an alkaline secondary battery has been made of a sintered sintered metal having continuous pores and ultrafine continuous pores as compared with the continuous pores (hereinafter referred to as micropores in a skeleton). A sponge-like fired metal plate having a structure composed of a skeleton portion is used. The continuous pores have an average pore diameter of 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%. It is said that the porosity of the entire metal plate is preferably in the range of 90 to 99%.

す る に は In order to manufacture this sponge-like fired metal plate, an apparatus shown in the sectional explanatory view of FIG. 12 is generally used. In FIG. 12, 6 is a carrier sheet, 7 is a doctor blade, 8 is a foaming slurry, 9 is a high-temperature and high-humidity tank, 11 is a drying tank, 12 is a hopper, 13 is a take-out reel, 14 is a take-up reel, and 15 and Reference numeral 16 denotes a support roll.

A surfactant and a foaming agent are added to a slurry composed of the raw material powder and thinner to prepare a foamed slurry 8, which is stored in a hopper 12, and the foamed slurry 8 is transferred to a carrier sheet 6 as shown in FIG. It is formed into a thin plate by a doctor blade 7 and foamed into a sponge in a high-temperature and high-humidity tank 9 by utilizing the vapor pressure of a volatile organic solvent contained in the foamed slurry and the foaming property of a surfactant. Further, it is dried in a drying tank 11 to produce a sponge-like green plate 10 ′, and the sponge-like green plate 10 ′ is degreased and fired by passing through a degreasing device and a firing furnace (neither is shown). We manufacture sponge-like fired metal plates with holes.

In order to strengthen the sponge-like fired metal plate thus produced, generally, a metal layer having a normal punched hole, a metal net, or a plurality of thin metal layers is resistance-welded to one side of the sponge-like fired metal plate. Then, a reinforcing layer is formed and integrated to reinforce.

However, when such a sponge-like fired metal plate is integrated by resistance welding with a metal tape having a punching hole, a metal net, or the like, the manufacturing process of the sponge-like fired metal plate, the sponge-like fired metal plate, the metal tape, and the metal net It requires at least two steps of resistance welding, etc., and is costly to manufacture. It is not preferable. Also, when performing resistance welding of a metal tape, a metal net, etc. to a sponge-like fired metal plate, a sponge-like fired metal is rolled with an electrode roll. There were problems such as crushing the holes of the plate, thereby reducing the porosity of the sponge-like fired metal plate.
Further, on a metal tape having a punched hole, a metal mesh, etc., the foamed slurry is formed into a thin plate by a doctor blade method, and the vapor pressure of the volatile organic solvent contained in the foamed slurry in a high-temperature and high-humidity bath and A sponge-like green plate having continuous pores is formed by foaming into a sponge shape by utilizing the foaming property of a surfactant, and the sponge-like green plate is degreased and metal tape having a punching hole by firing, A method is also conceivable in which a sponge-like fired metal plate having continuous pores is laminated on a metal mesh or the like, thereby producing a high-strength sponge-like fired metal composite plate. For composite boards, the shrinkage ratio of the sponge-like green plate during degreasing and firing is much higher than that of 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 active material is impregnated into a sponge-like fired metal layer of a high-strength sponge-like fired metal composite plate and rolled 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.

Therefore, the present inventors have conducted research to solve this problem,
(A) A slurry composed of a mixture of raw material powder and thinner or a mixture of raw material powder, thinner and surfactant was spread on a carrier sheet by a doctor blade method and heated. A green layer for forming a fired metal dense reinforcing layer by drying (hereinafter, referred to as a dense reinforcing green layer) is formed, and a raw material powder, a thinner, a surfactant, and a foaming agent are placed on the dense reinforcing green layer. The slurry prepared by addition (hereinafter referred to as a foamed slurry) was spread by a doctor blade method and heated. Forming a green layer (hereinafter, referred to as a sponge-like green layer) for forming a sponge-like fired metal layer on the dense reinforcement green layer to form a composite green comprising a dense reinforcement green layer and a sponge-like green layer When a composite green plate is prepared and degreased and fired, a high porosity sponge-like fired metal layer having continuous holes (hereinafter referred to as “continuous holes”) opened on the surface and connected to internal holes is formed. A high-strength sponge-like fired metal composite plate obtained by laminating a fired metal dense reinforcing layer having a porosity smaller than the porosity of the sponge-like fired metal layer and having a higher density and a higher strength than the sponge-like fired metal layer The sponge-like fired metal composite plate does not bend in the degreasing / firing step and does not crack in the sponge-like fired metal layer. 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 is preferably 0.5 to 30% (preferably 1 to 5%) of the total thickness of the high-strength sponge-shaped fired metal composite plate.
(C) The fired metal dense reinforcing layer is a finer continuous hole (hereinafter, referred to as a continuous fine hole) than the continuous hole of the sponge-like fired metal layer which is open on the surface and is continuous with the inner hole. And has high strength and high electrical conductivity due to having a porosity smaller than that of the sponge-like fired metal layer, but the fired metal dense reinforcing layer has a porosity of 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 more dense fired metal dense reinforcing layer having a porosity of less than 4% by volume can be formed, and further, a void-free porosity: 0% by volume. Can be formed, and the porosity is less than 4% by volume or even if the fired metal dense reinforcement layer having no voids is laminated with the sponge-like fired metal layer by firing, the shrinkage rate during firing is still It was found that there was no significant difference from the shrinkage rate of the sponge-like fired metal layer during firing, and that there was no curving or cracking of the sponge-like fired metal layer.

The present invention has been made based on such knowledge,
(1) A high-strength fired metal having a porosity smaller than the porosity of the sponge-shaped fired metal layer: 0 to 55 (including 0) volume% in the sponge-shaped fired metal layer having continuous pores A high-strength sponge-like fired metal composite plate obtained by laminating dense reinforcement layers, wherein the thickness of the fired metal dense reinforcement layer is 0.5 to 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 thickness,
(2) High strength having high porosity sponge-like fired metal layer having continuous porosity and having porosity smaller than porosity of sponge-like fired metal layer: 4 to 55% by volume A high-strength sponge-like fired metal composite plate obtained by laminating fired metal dense reinforcing layers, wherein the thickness of the fired metal dense reinforcement layer is 0.5 to 0.5% 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 thickness of 30%,
(3) High-strength sponge-like sintering in which a high-porosity sponge-like sintering metal layer having continuous porosity is laminated with a high-strength sintering metal dense reinforcing layer having a porosity of less than 4% by volume or no porosity. A metal composite plate, wherein the thickness of the fired metal dense reinforcing layer is 0.5 to 30% of the total thickness of the high-strength sponge-like fired metal composite plate; It is characterized by the following.

A high-strength sponge-like fired metal composite plate having a fired metal dense reinforcing layer for imparting strength on one side or inside of a sponge-like fired metal layer having a high porosity can be provided. The plate can be used as a material for manufacturing various filters and electrode substrates for alkaline secondary batteries.The electrode substrates for alkaline secondary batteries obtained using this high-strength sponge-like fired metal composite plate are Since the average packing density of the active material is higher than that of the active material, the resistance is low, and the current collection efficiency can be improved, which 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%. However, even if sufficient strength is obtained, the active material cannot be sufficiently filled when used as an electrode substrate of an alkaline secondary battery, which is not preferable. Therefore, the thickness of the fired metal dense reinforcing layer of the present invention is determined to be 0.5 to 30% (preferably 1 to 5%) of the total thickness of the high-strength sponge-shaped 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 and having continuous pores has continuous pores having an average pore diameter of 100 to 700 μm. Further, the sponge-like fired metal layer having a high porosity having the continuous pores has a continuous pore 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 section of the prior art. It may be a sponge-like fired metal layer composed of a porosity having fine pores: 10 to 55% by volume and a total porosity of 70 to 99% by volume.

The high-strength sponge-like fired metal composite plate having the high-strength fired metal dense reinforcing layer of the present invention laminated thereon will be described in more detail with reference to the drawings.
FIG. 1 shows a high-strength sponge-like fired metal layer 22 having continuous porosity 1 on one side of a high-strength fired metal dense reinforcing layer 21 having a porosity of 4 to 55% by volume according to the present invention. FIG. 3 is an enlarged cross-sectional model diagram of a sponge-like fired metal composite plate 20.
FIG. 2 shows a high-strength sponge-like fired metal layer 22 having continuous porosity 1 on both sides of a high-strength fired metal dense reinforcing layer 21 having a porosity of 4 to 55% by volume according to the present invention. FIG. 3 is an enlarged cross-sectional model diagram of a sponge-like fired metal composite plate 20.
This sponge-like fired metal layer 22 generally comprises continuous pores 1 and a skeleton portion 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 the sponge-shaped fired metal layer 22, the sponge-shaped fired metal layer 22 is formed on one or both sides of the fired metal dense reinforcing layer 21. To be laminated. The high-strength sponge-like fired metal composite plate 20 of the present invention, which is composed of the fired metal dense reinforcing layer 21 and the known sponge-like fired metal layer 22 shown in FIGS. The thickness of the reinforcing layer 21 is 0.5 to 30% of the total thickness of the high-strength sponge-like fired metal composite plate 20.

FIG. 3 shows a high-strength spongy fired metal layer 32 having continuous porosity 1 on one side of a high-strength fired metal dense reinforcing layer 21 having a porosity of 4 to 55% by volume according to the present invention. FIG. 3 is an enlarged cross-sectional model diagram of a sponge-like fired metal composite plate 20.
FIG. 4 shows a high-strength sponge-like fired metal layer 32 having continuous porosity 1 on both sides of a high-strength fired metal dense reinforcing layer 21 having a porosity of 4 to 55% by volume according to the present invention. FIG. 3 is an enlarged cross-sectional model diagram of a sponge-like fired metal composite plate 20.

3 and 4, a high porosity sponge-like fired metal layer 32 having continuous pores 1 laminated on one or both sides of the fired metal dense reinforcing layer 21 is composed of continuous pores 1 and a skeleton portion 33, and has a skeleton. The portion 33 includes micropores 34 in the skeleton, and has a total porosity of 70 to 99%. The continuous pores 1 have an average pore diameter of 100 to 700 μm, the skeleton portion 33 has an average pore diameter of the micro pores 34 in the skeleton of 0.5 to 20 μm, a porosity of 10 to 55%, and a sponge. The porosity of the entire shaped 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, which is composed of the fired metal dense reinforcing layer 21 and the known sponge-like fired metal layer 22 shown in FIGS. The thickness of the reinforcing layer 21 is 0.5 to 30% of the total thickness of the high-strength sponge-like fired metal composite plate 20. The average pore diameter of the high-strength fired metal dense reinforcing layer 21 having a porosity of 4 to 55% by volume is preferably in the range of 1 to 100 μm.

In order to manufacture the high-strength sponge-like fired metal composite plate 20 of the present invention shown in FIGS. 1 to 4, first, as shown in the sectional explanatory view of FIG. The foamed slurry 8 is supplied on the sheet 6 and the foamed slurry 8 is supplied onto the carrier sheet 6 on which the densely reinforced green tape 17 is placed. And foamed in a sponge form in a high-temperature and high-humidity tank 9 utilizing the vapor pressure of the volatile organic solvent contained in the foamed slurry 8 and the foaming property of the surfactant. After drying, a composite green plate 10 composed of a densely reinforced green layer and a sponge-like green layer is produced. Degreasing by passing not shown), baked to produce a high strength spongy sintered metal composite plate 20 of the present invention.

In FIG. 5, reference numeral 7 denotes a doctor blade, 9 denotes a high-temperature / high-humidity tank, 11 denotes a drying tank, 12 denotes a hopper, 13 denotes a take-out reel, 14 denotes a take-up reel, and 15 and 16 denote support rolls. Are the same as those in FIG. 12, and the description of the operation is omitted. The composite green plate composed of the dense reinforcement 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 3 and a high-strength material 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 manufactured.

In FIG. 5, the dense reinforcing green tape 17 prepared in advance is supplied. As shown in the cross-sectional explanatory view of FIG. 6, the dense reinforcing layer forming slurry 19 stored in the hopper 12 is placed on the carrier sheet 6. And the dense reinforcing layer forming slurry 19 is thinly spread by the doctor blade 7 ′ to form a dense reinforcing slurry layer 24 on the carrier sheet 6, and the dense reinforcing slurry layer 24 is transferred to the high-temperature / high-humidity tank 9 ′. The surface is lightly greened by passing through, and then the foamed slurry layer is formed while supplying the foamed slurry 8 onto the dense reinforcing slurry layer 24 whose surface is lightly greened, and then the high-temperature / high-humidity tank 9 and A composite green plate 10 composed of a densely reinforced green layer and a sponge-like green layer is prepared by passing the composite green plate 10 through a drying tank 11. The green plate is degreased and fired by passing it through a degreasing device and a firing furnace (neither is shown) to produce the high-strength sponge-like fired metal composite plate 20 of the present invention shown in FIGS. 1 and 3. .

The high-temperature and high-humidity tank 9 'is provided to lightly green the surface of the dense reinforcing slurry layer 24 so that the dense reinforcing layer forming slurry 19 and the foaming slurry 8 are not mixed when the composite green plate is manufactured. 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 having no voids is laminated. Porosity: less than 4% by volume or a high-strength fired metal dense reinforcing layer having no pores, because of insufficient air permeability, the fired metal dense reinforcing layer provided with a plurality of punched holes, and a reticulated fired metal dense reinforcing layer It is necessary to laminate fired metal dense reinforcing layers arranged in parallel at intervals.

{Porosity of the present invention: 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. 7 is an explanatory plan view of a high-strength sponge-like fired metal composite plate 20 having a high-strength fired metal dense reinforcing layer having a porosity of less than 4% by volume or having no voids according to the present invention, and FIG. 8 is a sectional view taken along the line II of FIG. 7 and 8, reference numeral 1 denotes continuous pores, and reference numeral 2 denotes a high-strength fired metal dense reinforcing layer having a porosity of less than 4% by volume or no pores. As shown in FIGS. 7 and 8, the high-strength sponge-like fired metal composite plate 20 having the fired metal dense reinforcing layer 2 is provided on one side of the sponge-like fired metal layer 22 and in the longitudinal direction of the sponge-like fired metal layer 22. The strip-shaped fired metal dense reinforcing layers 2 having a narrow width in parallel are formed at intervals, and the high-strength sponge-shaped fired metal composite board 20 having the fired metal dense reinforcing layer 2 shown in FIGS. It can be cut into a predetermined shape and used as it is as a high-temperature filter or an air purifier filter.

In the high-strength sponge-like fired metal composite plate 20 shown in FIGS. 7 and 8, as shown in FIG. 9, the portion having the fired metal dense reinforcing layer 2 and the portion having the continuous holes 1 are paired. Thus, the electrode substrate 3 of the alkaline secondary battery can be manufactured. As shown in FIG. 9, the fired metal dense reinforcing layer 2 exists, 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, and thus the continuous empty The proportion occupied by the holes 1 does not decrease, and the amount of active material contained in the entire electrode does not decrease due to welding of the current collecting tab.

In FIG. 7, the fired metal dense reinforcing layer 2 formed on one surface of the high-strength sponge-shaped fired metal composite plate 20 of the present invention is formed by narrow strip-shaped fired metal dense reinforcing layers 2 spaced apart in parallel in the length direction. However, the shape may be a lattice shape or a net shape (not shown), or may be 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. 10 is prepared in advance, and the dense reinforcing green tape 17 having punching holes 18 is formed as shown in the sectional explanatory view of FIG. The foam slurry is supplied on the carrier sheet 6 and supplied on the dense reinforcing green tape 17 having the punching holes 18 while the foaming slurry 8 is supplied on the dense reinforcing green tape 17 having the punching holes 18. 8 is formed into a thin plate, foamed into a sponge shape by utilizing the vapor pressure of a volatile organic solvent contained in the foamed slurry 8 and the foaming property of a surfactant, and then dried to form a dense reinforcing green layer and A composite green plate composed of a sponge-like green layer was prepared, and the composite green plate was degreased and fired (both shown in the drawing). ), And then degreased and baked, and as shown in the plan view of FIG. 11A and the cross-sectional view of FIG. The high-strength sponge-like fired metal composite plate 20 of the present invention having the metal dense reinforcing layer 2 can be manufactured. As shown in the plan view of FIG. 11A and the cross-sectional view of FIG. 11B, the high-strength sponge-like fired metal composite plate 20 The structure is exposed from the punching holes 18 of the fired metal dense reinforcing layer 2 on the back surface of the fired metal composite plate 20.

As shown in FIGS. 5 and 6, the high-strength sponge-like fired metal composite plate according to the present invention has a mixture of raw material powder (filler) and thinner or a mixture of raw material powder (filler), thinner and surfactant. The slurry composed of the body was spread on the carrier sheet by the doctor blade method and heated. Forming a dense reinforced green layer to form a dried and fired metal dense reinforced layer,
On this dense reinforcing green layer, a foaming slurry prepared by adding a raw material powder (filler), a thinner, a surfactant and a foaming agent was spread by a doctor blade method and heated. By drying and forming a sponge-like green layer for forming a sponge-like fired metal layer on the dense reinforcement green layer, a composite green plate composed of the dense reinforcement green layer and the sponge-like green layer is produced, It can be manufactured by degreasing and firing a green plate.

Porosity: A high-strength sponge-like fired metal composite plate obtained by laminating a high-porosity sponge-like fired metal layer having continuous pores on both sides of a fired metal dense reinforcing layer having 0 to 55 (including 0) volume%. Is prepared by spreading the foamed slurry by a doctor blade method on the dense reinforcing green layer of the composite green plate prepared in the above (4), and then drying the foamed slurry to form a sponge-like material on both surfaces of the dense reinforcing green layer. A composite green plate having a green layer formed thereon is prepared, and the composite green plate can be prepared by degreasing and firing.

Further, a high-strength sponge-like fired metal obtained by laminating a high-porosity sponge-like fired metal layer having continuous pores on both surfaces of a fired metal dense reinforcing layer having a porosity of 0 to 55 (including 0) volume%. In order to produce a composite plate, a composite green plate produced by overlapping and bonding a sponge-like green layer prepared in advance on the dense reinforcing green layer of the composite green plate prepared in FIGS. 5 and 6 is used. The composite green plate can be manufactured by degreasing and firing.

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, a filter for an air purifier, and an electrode substrate of an alkaline secondary battery. In particular, it is preferable to produce an electrode substrate for an alkaline secondary battery. Therefore, the present invention
(4) An electrode substrate of an alkaline secondary battery produced using the high-strength sponge-like fired metal composite plate described in (1) to (3).
The raw material powder for manufacturing the high-strength sponge-like fired metal composite plate of the present invention is preferably Ni powder, Ni-based alloy powder, Cu powder, Cu-based alloy powder, Fe powder or Fe-based alloy powder. However, other metal powders may be used, and the present invention is not limited to this.

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

First, the dense reinforcing layer forming slurry 19 shown in Table 1 is formed on the carrier sheet 6 of FIG. 6 with a blade gap of 0.1 mm to form a dense reinforcing slurry layer 24, 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 a hopper 12 for storing the foaming slurry 8 shown in Table 2, and the foaming slurry 8 is coated with a blade gap of 0.4 mm. Is supplied to the high-temperature / high-humidity tank 9 shown in FIG. 6, where foaming is performed under the conditions of a temperature of 40 ° C., a humidity of 90%, and a holding time of 20 minutes, and then a temperature of 80 ° C. Then, hot air drying was performed for 15 minutes to prepare a composite green plate 10 comprising a dense reinforcing green layer and a sponge-like green layer.

While passing the composite green plate through a degreasing apparatus (not shown), the composite green plate is degreased under the condition of holding in air at 500 ° C. for 15 minutes. Then, while passing through a firing furnace (not shown), 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, the composite plate of the present invention) was prepared.

The composite plates 1 to 3 of the present invention thus obtained were partially embedded in resin, the cross section was polished, and observed with an optical microscope at a magnification of 100 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 curvature and the occurrence of cracks in the sponge-like fired metal layer were observed. The results are shown in Table 3. Furthermore, it was cut into a JISZ2201 (metallic material tensile test piece) No. 13A shape by an electric discharge machine and subjected to a tensile test, further 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.

Further, 1% by weight of carboxymethyl cellulose (CMC), 3% by weight of polytetrafluoroethylene (PTFE), and 30% by weight of pure water based on a mixed powder composed of 92% by weight of nickel hydroxide powder and 8% by weight of cobalt monoxide powder. %, And kneaded to prepare a paste-like active material, impregnate the composite plates 1 to 3 of the present invention with the active material, dry the material at a temperature of 100 ° C. for 3 hours, and further use a rolling roll. After rolling by 30%, the cross sections of the composite plates 1 to 3 of the present invention after the rolling were observed with an optical microscope, and the presence or absence of peeling of the sponge-like fired metal layer and the fired metal dense reinforcing layer was observed. The results are shown in Table 3. Was.

Conventional example 1
A foamed slurry shown in Table 2 of Example 1 was applied on the surface of a Ni thin plate having punched holes: 60 μm by a doctor blade method, and a Ni thin plate provided with punched holes under the same conditions as in Example 1. A composite board 1 having a sponge-like fired metal layer formed on the surface thereof was manufactured. The same measurement and observation as in Example 1 were performed on the obtained conventional composite board 1, and the results are shown in Table 3.

Conventional example 2
A foamed slurry shown in Table 2 of Example 1 was used to prepare a sponge-like fired metal plate having no dense reinforcing layer by a doctor blade method, and the obtained plate was measured and observed in the same manner as in Example 1, and the results were obtained. Are shown in Table 3.

From the results shown in Table 3, it can be seen that all of the composite plates 1 to 3 of the present invention can be used as a material for producing a high temperature filter, a filter for an air purifier, and an electrode substrate of an alkaline secondary battery. However, the conventional composite plate 1 bends toward the sponge-like fired metal layer side, and when trying to correct it, a crack is generated in the sponge-like fired metal layer. 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 low strength, cannot be used as an air purifier filter for a high-temperature filter, and has a high specific resistance. Could not be obtained.

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

First, the dense reinforcing layer forming slurry 19 shown in Table 4 is formed on the carrier sheet 6 of FIG. 6 with the blade gap shown in Table 6 to form the dense reinforcing slurry layer 24, and this slurry layer is placed in the high temperature / high humidity tank 9 '. After drying the surface lightly by drying at 30 ° C. for 2 minutes, this was supplied under a hopper 12 for storing the foamed slurry 8 shown in Table 5, and the foamed slurry 8 was supplied with a blade gap shown in Table 6 A layered slurry is prepared by coating, and the layered slurry is supplied to the high-temperature / high-humidity tank 9 shown in FIG. 6, where it is foamed under the conditions of temperature: 40 ° C., humidity: 90%, and holding for 20 minutes. Hot air drying was performed at a temperature of 80 ° C. for 15 minutes to prepare a composite green plate comprising a dense reinforcing green layer and a sponge-like green layer.

A 1.5 mm thick sponge-like green tape prepared in advance is placed on the dense green layer side of the composite green plate on the composite green plate comprising the dense reinforcement green layer and the sponge-like green layer obtained in this manner. The composite green plate having a sponge-like green layer on both sides of the densely reinforced green layer was produced by laminating and laminating the layers in an atmosphere of temperature: 50 ° C. and humidity: 90%.

While passing the bonded composite green plate through a degreasing device (not shown), the bonded green plate is degreased at a temperature of 500 ° C. in air for 15 minutes, and then passed through a firing furnace (not shown). The composite plate 4 of the present invention having a sponge-like fired metal layer on both sides of a fired metal dense reinforcing layer shown in Table 6 by firing in an N ₂ -5% H ₂ atmosphere at 1100 ° C. for 10 minutes. No. 6 was produced.

With respect to the composite plates 4 to 6 of the present invention thus obtained, the porosity of the sponge-like fired metal layer and the fired metal dense reinforcing layer and the ratio of these thicknesses were measured in the same manner as in Example 1, and the curvature was measured. And the presence or absence of cracks in the sponge-like fired metal layer was observed. The results are shown in Table 6. Furthermore, it was cut into a JISZ2201 (metallic material tensile test piece) No. 13A shape by an electric discharge machine and subjected to a tensile test, further 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 6.

1% by weight of carboxymethyl cellulose (CMC), 3% by weight of polytetrafluoroethylene (PTFE), and 30% by weight of pure water were added to a mixed powder composed of 92% by weight of nickel hydroxide powder and 8% by weight of cobalt monoxide powder. Then, a paste-like active material was produced by kneading. The composite plates 4 to 6 of the present invention are impregnated with the active material, dried at 100 ° C. for 3 hours, and further rolled by 30% using a rolling roll. Observation with a microscope was conducted to observe whether or not the sponge-like fired metal layer and the fired metal dense reinforcing layer were separated, and the results are shown in Table 6.

Conventional example 3
Foaming slurry shown in Table 5 of Example 2 was applied on both sides of a Ni thin plate having punched holes: 60 μm by a doctor blade method, and Ni thin plates provided with punched holes under the same conditions as in Example 2. The conventional composite plate 1 having the sponge-like fired metal layers formed on both surfaces was manufactured, and the obtained conventional composite plate 3 was measured and observed in the same manner as in Example 2. The results are shown in Table 6.

Conventional example 4
The foamed slurry shown in Table 5 of Example 2 was formed by a doctor blade method, degreased and fired in the same manner as in Example 2 to produce a sponge-like fired metal sheet having no dense reinforcing layer, and the obtained sheet was obtained. Was measured and observed in the same manner as in Example 2, and the results are shown in Table 6.

結果 From the results shown in Table 6, it can be seen that the composite plates 4 to 6 of the present invention can be used as a material for producing a high temperature filter, a filter for an air purifier, and an electrode substrate of an alkaline secondary battery. However, the conventional composite plate 3 cannot be used as a material for producing a high-temperature filter, a filter for an air purifier, or an electrode substrate of an alkaline secondary battery, for example, a crack is generated in a sponge-like fired metal layer. In addition, the sponge-like fired metal plate of Conventional Example 4 has a small strength, cannot be used as an air purifier filter for a high-temperature filter, and has a high specific resistance. Could not be obtained.

Example 3
First, a thinner was prepared using the composition shown in Table 7, a filler was added thereto, and the mixture was kneaded in a closed container for 8 hours to form a slurry, molded by a known doctor blade method, air-dried, and then dried to a width of 4 mm. A long, dense, reinforced green tape having a size of 0.1 mm in thickness and 4 mm in width by slitting and having a porosity of 0% was produced.

Next, according to the composition shown in Table 8, first, a filler and a thinner were kneaded for 24 hours, then a surfactant was added and kneaded under reduced pressure for 15 minutes. The mixture was kneaded for a minute to prepare a foamed slurry.

As shown in FIG. 5, the dense reinforcing green tape was supplied on a carrier sheet at intervals of 6 cm, and the foamed slurry was spread on the carrier sheet on which the dense reinforcing green tape was placed, with a blade gap of 0.4 mm. Vaporized volatile organic solvent contained in the foamed slurry at a temperature of 40 ° C. and a humidity of 90% for 20 minutes at a feed rate of 0.4 mm / min. After foaming into a sponge shape by utilizing the pressure and the foaming property of a surfactant, drying with hot air, drying at a temperature of 80 ° C. for 15 minutes, and a dense reinforced green tape and sponge-like green layer on one surface Was prepared.
Further, a sponge-like green layer having a porosity of 96% is further laminated on the dense green tape side of the composite green plate, and a composite green plate having a dense reinforcing green tape incorporated in the high porosity sponge green (not shown). Was produced.

While passing these composite green plates through a degreasing device (not shown), they are degreased in air at a temperature of 600 ° C. for 30 minutes, and then passed through a firing furnace (not shown). _The composite plate 7 of the present invention having a fired metal dense reinforcing layer was manufactured by firing under the conditions of 2-5% H ₂ , temperature: 1100 ° C., and holding for 30 minutes. The composite plate 7 of the present invention was cut into a JISZ2201 (metallic material tensile test piece) 13A shape by an electric discharge machine to prepare a tensile test piece having a fired metal dense reinforcing layer and a tensile test piece having no fired metal dense reinforcing layer. A tensile test was performed using this tensile test piece, and the results are shown in Table 9.

結果 From the results shown in Table 9, it is found that the provision of the fired metal dense reinforcing layer significantly improves the tensile strength of the sponge-like porous metal plate.

Example 4
Next, the composite plate of the present invention obtained in Example 3 was cut by 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 the active material containing nickel hydroxide as a main component is filled in the electrode substrate of the alkaline secondary battery of the present invention, the material is rolled and pressed at a draft of 50%, and the entire average active material including the fired metal dense reinforcing layer is filled. The density was measured, and the results are shown in Table 10.

Further, for comparison, a sponge-like green plate was produced from the foamed slurry shown in Table 8 using the apparatus shown in FIG. 12 under the same conditions as in Example 3, and this sponge-like green plate was produced in the same manner as in Example 3. Degreasing was performed under the same conditions, followed by baking under the same conditions as in Example 3 to produce a sponge-like porous metal plate. A nickel tape was joined to the sponge-like porous metal plate by resistance welding, and the sponge-like porous metal plate joined with the nickel tape was cut by an electric discharge machine to prepare an electrode substrate of a conventional alkaline secondary battery. The obtained electrode substrate of the conventional alkaline secondary battery was filled with an active material containing nickel hydroxide as a main component, and was roll-pressed at a rolling reduction of 50%, and the average active material filling density including the nickel tape joint was determined. The measurement was performed, and the results are shown in Table 10.

As is clear from the results shown in Table 10, the electrode substrate of the alkaline secondary battery of the present invention manufactured using the sponge-like porous metal plate manufactured by the method of the present invention is the same as the electrode substrate of the conventional alkaline secondary battery. It can be seen that the average active material packing density can be increased by 4% as compared with that.

Example 5
Dense reinforcing layer forming slurries A to E having the compositions shown in Table 11 and foaming slurries A to E having the compositions shown in Table 12 were produced.

The dense reinforcing layer forming slurry A shown in Table 11 is stored in the hopper 12 ', the foaming slurry A shown in Table 12 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 was formed with a thickness of 2 mm, and the slurry layer was passed through a high-temperature and high-humidity tank 9 ′ and dried at 30 ° C. for 2 minutes to lightly dry the surface. Is supplied under a hopper 12 for storing the foamed slurry, and a foamed slurry 8 is applied with a blade gap of 0.5 mm to produce a laminated slurry. The laminated slurry is supplied to a high-temperature and high-humidity tank 9 shown in FIG. After foaming at a temperature of 40 ° C. and a humidity of 90% for 20 minutes, a hot air drying is performed at a temperature of 80 ° C. for a period of 15 minutes to obtain a dense reinforced green layer. And a composite green plate comprising a sponge-like green layer.

The composite green plate is degreased under the conditions shown in Table 13 while passing through a degreasing device (not shown), and then fired under the conditions shown in Table 13 while passing through a firing furnace (not shown). In this way, a composite plate 8 of the present invention comprising a sponge-like fired metal layer and a fired metal dense reinforcing layer shown in Table 14 was produced.
For the composite plate 8 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 curvature, and the sponge-like firing It was observed whether a crack had occurred in the metal layer, and the results are shown in Table 14.

The dense reinforcing layer forming slurry B of Table 11 and the foaming slurry B of Table 12, the dense reinforcing layer forming slurry C of Table 11 and the foaming slurry C of Table 12, the dense reinforcing layer forming slurry D of Table 11 and the foaming slurry D of Table 12 For the dense reinforcing layer forming slurry E in Table 11 and the foaming slurry E in Table 12, a composite green plate was prepared in the same manner as the dense reinforcing layer forming slurry A and the foaming slurry A in Table 12, and these composite green plates were degreased. By degreased under the conditions shown in Table 13 while passing through an apparatus (not shown), and then baked under the conditions shown in Table 13 while passing through a firing furnace (not shown), The composite plates 9 to 12 of the present invention comprising the shown sponge-like fired metal layer and fired metal dense reinforcing layer were produced.

With respect to the composite plates 9 to 12 of the present invention thus obtained, the presence or absence of curvature and the occurrence of cracks in the sponge-like fired metal layer were observed in the same manner as in Example 1, and the results were shown in Table 14. It was shown to.

From the results shown in Table 14, the composite plates 9 to 12 of the present invention produced by the method of the present invention do not bend anymore, and furthermore, the sponge-like fired metal layer does not generate cracks. It can be seen that it can be used as a material for producing a filter for an air purifier.

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

It is a cross-sectional enlarged model diagram of a high-strength sponge-like fired metal composite plate. It is a cross-sectional enlarged model diagram of a high-strength sponge-like fired metal composite plate. It is a cross-sectional enlarged model diagram of a high-strength sponge-like fired metal composite plate. It is a cross-sectional enlarged model diagram of a high-strength sponge-like fired metal composite plate. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the apparatus for manufacturing the composite green board which has the dense reinforcement green layer used for manufacture of the high-strength sponge-like fired metal composite board of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the apparatus for manufacturing the composite green board which has the dense reinforcement green layer used for manufacture of the high-strength sponge-like fired 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. 1 is a plan view of an electrode substrate of an alkaline secondary battery manufactured using a high-strength sponge-like fired metal composite plate of the present 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 punched holes. It is sectional explanatory drawing of the apparatus for manufacturing the composite green plate used for manufacture of the conventional sponge-like porous metal plate.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Continuous pore 2 Fired metal dense reinforcement layer 3 Electrode substrate of 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 plate 11 Drying tank 12 Hopper 12 'Hopper 13 Unwind reel 14 Take-up reel 15 Support roll 16 Support roll 17 Dense reinforcing green tape 18 Punching hole 19 Dense reinforcing layer forming slurry 20 High-strength sponge-like porous metal composite plate 21 Firing metal dense reinforcing layer 22 Sponge-like firing metal layer 23 Skeleton part 24 Dense reinforcing slurry layer 32 Sponge-like fired metal layer 33 Skeleton part 34 Fine pores in skeleton

Claims (13)

A porosity smaller than the porosity of the sponge-like fired metal layer having a high porosity sponge-like fired metal layer having continuous pores (hereinafter, referred to as continuous pores) opened on the surface and connected to internal pores A high-strength sponge-like fired metal composite plate obtained by laminating high-strength fired metal dense reinforcing layers having a volume percentage of 0 to 55 (including 0), wherein the fired metal dense reinforcing layer has a high strength. A high-strength sponge-like fired metal composite plate having a thickness of 0.5 to 30% of the total thickness of the sponge-like fired metal composite plate. The sponge-like fired metal layer of high porosity having continuous pores has continuous pores that are finer than the continuous pores of the sponge-like fired metal layer that is open to the surface and is continuous with internal pores. A high-strength sponge-like fired metal composite plate obtained by laminating high-strength fired metal dense reinforcing layers having a porosity smaller than the porosity of the sponge-like fired metal layer: 4 to 55% by volume, wherein the fired metal is The high-strength sponge-like fired metal composite plate, wherein the dense reinforcing layer has a thickness of 0.5 to 30% of the total thickness of the high-strength sponge-like fired metal composite plate. A high-strength sponge-like fired metal composite plate comprising a high-porosity sponge-like fired metal layer having continuous pores and a high-strength fired-metal dense reinforcing layer having a porosity of less than 4% by volume or having no voids laminated thereon. Wherein the fired metal dense reinforcing layer has a thickness of 0.5 to 30% of the total thickness of the high-strength sponge-shaped fired metal composite plate. Board. The high-strength sponge-like fired metal composite according to claim 1, 2 or 3, wherein the fired metal dense reinforcing layer is laminated on one surface of the high-porosity sponge-like fired metal layer having the continuous pores. Board. 4. A high-strength sponge-like fired metal composite according to claim 1, 2 or 3, wherein a high porosity sponge-like fired metal layer having the continuous pores is laminated on both surfaces of the fired metal dense reinforcing layer. Board. The high-strength sponge-like fired metal composite according to claim 1, 2 or 3, wherein the fired metal dense reinforcing layer is incorporated in the high porosity sponge-like fired metal layer having the continuous pores. Board. The high-strength sponge according to claim 1, 2, 3, 4, 5, or 6, wherein the high-porosity sponge-like fired metal layer having continuous pores has a porosity of 70 to 99% by volume. Shaped 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 has a porosity of 70 to 99% by volume. The high-strength sponge-like fired metal composite plate according to 2, 3, 4, 5, 6, or 7. The high porosity sponge-like fired metal layer having the continuous pores has a continuous pore having an average pore diameter of 100 to 700 μm and a porosity having fine pores in the skeleton having an average pore diameter of 0.5 to 20 μm: 10 The high strength according to claim 1, 2, 3, 4, 5, 6, 7, or 8 comprising a skeletal portion of about 55% by volume and having a porosity of 70 to 99% by volume. Sponge-like fired metal composite board. 7. The sponge-like fired metal layer and the fired metal dense reinforcing layer are each made of fired metal obtained by firing Ni powder or Ni-based alloy powder. 10. The high-strength sponge-like fired metal composite plate according to claim 7, 7, 8 or 9. An electrode substrate for an alkaline secondary battery produced using the high-strength sponge-like fired metal composite plate according to claim 10. Each of the sponge-like fired metal layer and the fired metal dense reinforcing layer is made of a fired metal obtained by firing Ni powder, Ni-based alloy powder, Cu powder, Cu-based alloy powder, Fe powder or Fe-based alloy powder. 10. The high-strength sponge-like fired metal composite plate according to claim 1, 2, 3, 4, 5, 6, 7, 8, or 9. A filter manufactured using the high-strength sponge-like fired metal composite plate according to claim 12.

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