JP6768435B2 - Covered aluminum material and its manufacturing method - Google Patents

Description

The present invention relates to a coated aluminum material and a method for producing the same.

The coated aluminum of the present invention is particularly useful as an electrode structure or a constituent member thereof used for an electrode or a current collector of a battery or a capacitor.

Conventionally, various coated aluminum materials have been proposed as coating aluminum materials used for electrodes or current collectors of batteries or capacitors.

For example, in Patent Document 1 (particularly claim 1), "aluminum material and
The carbon-containing layer formed on the surface of the aluminum material and
An intervening layer containing carbides of aluminum formed between the aluminum material and the carbon-containing layer in at least a part of the surface of the aluminum material is provided.
The carbon-containing layer contains a plurality of carbon-containing particles and contains
A carbon-coated aluminum material in which an organic substance layer is formed on the surface of the carbon-containing particles. "
Is disclosed.

In Patent Document 1, a resin layer is formed in advance on the surface in order to improve the adhesion between the carbon-containing layer, which is the coating portion, and the aluminum material, and the adhesion between the carbon-containing particles contained in the carbon-containing layer. It is disclosed that a carbon-containing layer containing carbon-containing particles is formed on the surface of an aluminum material and heated in a space containing a hydrocarbon-containing substance so that the resin layer remains as an organic layer even after the heating step. ([0009] to [0011] paragraphs, etc.). Specifically, by leaving the organic substance layer on the surface of the carbon-containing particles, the adhesion between the carbon coating layer and the aluminum material can be further enhanced in addition to the effect of the intervening layer, and the organic substance layer remains. It is described that this improves the adhesion between the carbon-containing particles.

Further, in Patent Document 2 (particularly claim 1), "aluminum material and
The organic layer formed on the surface of the aluminum material and
An intervening layer containing carbides of aluminum formed between the aluminum material and the organic material layer in at least a part of the surface of the aluminum material is provided.
The organic layer is a conductive coated aluminum material containing a carbon precursor. Is disclosed.

In Patent Document 2, a resin layer containing no carbon-containing particles is made of an aluminum material so that a conductor that guarantees surface conductivity due to moisture does not peel off from the aluminum material even when used under high humidity conditions. It is disclosed that the resin layer is made into an organic layer containing a carbon precursor exhibiting conductivity by forming it on a surface and heating it in a space containing a hydrocarbon-containing substance ([0008], [0028]. ] Paragraphs, etc.).

International Publication No. 2010-086961 Pamphlet Japanese Unexamined Patent Publication No. 2010-215964

However, the techniques of Patent Document 1 and Patent Document 2 have the following problems.

The carbon-coated aluminum material described in Reference 1 has the effect of increasing the surface area of the aluminum material by containing carbon-containing particles in the carbon-containing layer, but when exposed to a high-temperature, high-humidity atmosphere for a long period of time, , Moisture contained in the atmosphere may enter the gaps between the carbon-containing layers (gap between carbon-containing particles) and cause a hydration reaction at the interface between the carbon-containing particles and the aluminum material. Further, when a carbon-coated aluminum material is used for a battery or a capacitor, a corrosive component (acid or the like) contained in the battery or the capacitor often accelerates the progress of the hydration reaction.

Further, the carbon-coated aluminum material described in Reference 1 is heat-treated by stacking a plurality of intermediates in a state in which carbon-containing particles having a resin layer formed on the surface of the aluminum material are adhered for the purpose of improving production efficiency. When the band-shaped intermediate is wound in a coil shape and subjected to heat treatment, the intervening layer is not sufficiently formed in the central portion of the coated aluminum material, and the adhesion between the aluminum material and the carbon-containing layer is sufficient. It may not be possible to secure it.

The conductive material-coated aluminum material described in Patent Document 2 has excellent hydration resistance because the organic material layer does not contain carbon-containing particles and has a dense structure, but the surface smoothness of the organic material layer is high, so that the organic material layer When a slurry containing an active material is applied to the surface of the material, the wettability is poor, and the contact area between the organic layer and the active material layer is small, so that sufficient adhesion may not be obtained.

In this way, when a coated aluminum material in which a carbon-containing layer or an organic substance layer (hereinafter referred to as "organic substance layer") is formed on the surface of the aluminum material is used as an electrode or a current collector of a battery or a capacitor, aluminum is used. If the adhesion between the material and the organic material layer is weak, the organic material layer may peel off and short-circuit in the reliability test of the battery or the capacitor. Further, if the hydration resistance of the organic substance layer is low, the coated aluminum material may be corroded by the corrosive component used in the manufacturing process of the battery or the capacitor. Further, if the active material layer or the solid electrolyte is provided on the surface of the organic material layer, the adhesion between them is low, or if the surface of the organic material layer is difficult to get wet when the liquid electrolyte is used, the characteristics of the battery or the capacitor are adversely affected. There is a risk.

Therefore, it is a coated aluminum material in which an organic material layer is formed on the surface of the aluminum material via an intervening layer, and has hydration resistance, wettability between the organic material layer and the liquid electrolyte, and an active material layer or an active material layer on the surface of the organic material layer. These are excellent in adhesion when laminating solid electrolytes, and even when a coated aluminum material is efficiently manufactured by stacking a plurality of sheets or winding them in a coil shape and subjecting them to heat treatment, the aluminum material and the aluminum material are used. An object of the present invention is to provide a coated aluminum material having excellent adhesion to an organic material layer and a method for producing the same.

As a result of diligent research to achieve the above object, the present inventors have found that the above object can be achieved by the coated aluminum material obtained through a specific manufacturing method, and have completed the present invention. ..

That is, the present invention relates to the following coated aluminum and a method for producing the same.
1. 1. With aluminum material
The organic layer formed on the surface of the aluminum material and
An intervening layer formed between the aluminum material and the organic material layer,
It is a coated aluminum material provided with
(1) The intervening layer exists in at least a part of the surface of the aluminum material and contains carbides of aluminum.
(2) The organic material layer contains a carbon precursor, does not substantially contain conductive particles, is substantially composed of a resin component and the carbon precursor, and has an uneven portion on the surface of the organic material layer. The concave-convex portion has conical convex portions that are densely arranged, and the boundary between the adjacent ellipsoidal convex portions is connected by a concave portion, and the conical convex portion has a cross section when observed. The shape of the convex portion is a polygonal weight, a cone, a hemisphere or an ellipsoid, or a combination thereof, and the uneven portion has substantially no flat surface.
A coated aluminum material characterized by that.
2. Item 2. The coated aluminum material according to Item 1, wherein the recess has a continuous gradient.
3. 3. Item 2. The coated aluminum material according to Item 1 or 2, wherein the uneven portion has a surface roughness Rz of 1.2 μm or more and 5 μm or less.
4. In an arbitrary cross-sectional view in the height direction of the organic matter layer, from the height (T) from the apex of the convex portion to the bottom surface of the organic matter layer and the deepest portion of each of the two adjacent concave portions across the convex portion. Item 2. Coated aluminum material.
5. Item 2. The coated aluminum material according to any one of Items 1 to 4, which is an electrode structure or a constituent member thereof.
6. Item 5. The coated aluminum material according to Item 5, wherein the electrode structure is a current collector and / or an electrode of a capacitor.
7. Item 5. The coated aluminum material according to Item 5, wherein the electrode structure is a current collector and / or an electrode of a battery.
8. The strip-shaped coated aluminum material having a width of 10 mm and a length of 100 mm was immersed in a 1 mol / L hydrochloric acid solution at 80 ± 1 ° C., and the time required for the organic material layer to completely peel off from the coated aluminum material was measured for acid resistance. Item 2. The coated aluminum material according to any one of Items 1 to 7, which has a value exceeding 400 seconds in a sex evaluation test.
9 . It is a manufacturing method of coated aluminum material.
(1) Step 1 of preparing the resin particle dispersion liquid A by curing a part of the resin particles which are the dispersoids of the resin emulsion.
(2) Step 2 of forming a resin layer having uneven portions on the surface by applying the resin particle dispersion liquid A to one side or both sides of the aluminum material.
(3) By heating the aluminum material on which the resin layer is formed in an atmosphere containing a hydrocarbon-containing substance, the resin layer is changed to an organic layer containing a carbon precursor and having uneven portions on the surface. In addition, a step 3 of forming an intervening layer containing an aluminum carbide in at least a part of the surface of the aluminum material between the aluminum material and the resin layer.
A method for producing a coated aluminum material, which comprises, in order.
10 . In the concave-convex portion, the ellipsoidal convex portions are densely arranged, and the boundary between the adjacent ellipsoidal convex portions is connected by a concave portion having a continuous gradient, and the cross section of the ellipsoidal convex portion is observed. Item 2. The manufacturing method according to Item 9 , wherein the shape of the convex portion is a polygonal weight, a cone, a hemisphere or an ellipsoid, or a combination thereof, and the uneven portion has substantially no flat surface. ..
11 . Item 9. The production method according to Item 9 or 10 , wherein the resin particles have an average particle size of 5 μm or less.
12 . Item 8. The production method according to any one of Items 9 to 11 , wherein the resin layer and the organic substance layer do not substantially contain conductive particles.
13 . Item 2. The production method according to any one of Items 9 to 12 , wherein the uneven portion of the organic substance layer has a surface roughness Rz of 1.2 μm or more and 5 μm or less.
14 . In an arbitrary cross-sectional view in the height direction of the organic matter layer, from the height (T) from the apex of the convex portion to the bottom surface of the organic matter layer and the deepest portion of each of the two adjacent concave portions across the convex portion. Item 2. The item 9 to 13 above, wherein the ratio (T / D) to the distance (D) of the line segments indicating the height to the bottom surface of the organic substance layer is 0.2 or more and 1.1 or less. Production method.

The coated aluminum material of the present invention is excellent in hydration resistance because the organic material layer does not substantially contain conductive particles. Further, the surface of the organic material layer has an uneven portion, and the concave-convex portion is densely arranged with fornix-shaped convex portions, and the boundary between the adjacent fornix-shaped convex portions is connected by the concave portion. Has a substantially flat surface, which increases the surface area and is excellent in wettability with a liquid electrolyte. Moreover, when the active material layer or the solid electrolyte is further laminated on the surface of the organic material layer, these adhesions are excellent. Further, even when the coated aluminum material is efficiently produced by stacking a plurality of sheets or winding them in a coil shape and subjecting them to heat treatment (heat treatment in step 3 described later), the adhesion between the aluminum material and the organic material layer is improved. Are better. The method for producing a coated aluminum material of the present invention is suitable for producing such a coated aluminum material of the present invention.

It is sectional drawing which shows a preferable aspect of the coated aluminum material of this invention. In the cross-sectional view in the height direction of the organic substance layer, the height (T) from the apex of the convex portion to the bottom surface of the organic substance layer and the bottom surface of the organic substance layer from the deepest part of each of the two adjacent recesses sandwiching the convex portion. It is a schematic diagram which shows the distance (D) between line segments which show the height to. It is an observation image which observed the surface of the organic matter layer of the coated aluminum material produced in Example 1 by the scanning electron microscope (SEM) manufactured by JEOL Ltd. In order to make it easier to understand for observation, platinum vapor deposition is applied to the surface of the organic material layer to ensure conductivity. It is an observation image which observed the cross section in the height direction of the coating aluminum material produced in Example 1 by the field emission scanning electron microscope (FE-SEM) manufactured by Hitachi High-Technologies Corporation. In order to make it easier to understand for observation, platinum is vapor-deposited on the surface of the organic layer before cutting out the cross section, carbon paste is applied to ensure conductivity during observation, and then fixed to the aluminum foil. It is an observation image of the cross section cut by ion milling. It is sectional drawing of the coated aluminum material produced in the comparative example 5. FIG.

Hereinafter, the coated aluminum material of the present invention and a method for producing the same will be described in detail.

1. 1. Manufacturing Method of Covered Aluminum Material The manufacturing method of the coated aluminum material of the present invention is
(1) Step 1 of preparing the resin particle dispersion liquid A by curing a part of the resin particles which are the dispersoids of the resin emulsion.
(2) Step 2 of forming a resin layer having uneven portions on the surface by applying the resin particle dispersion liquid A to one side or both sides of the aluminum material.
(3) By heating the aluminum material on which the resin layer is formed in an atmosphere containing a hydrocarbon-containing substance, the resin layer is changed to an organic layer containing a carbon precursor and having uneven portions on the surface. In addition, a step 3 of forming an intervening layer containing an aluminum carbide in at least a part of the surface of the aluminum material between the aluminum material and the resin layer.
It is characterized by having.

Hereinafter, each step will be described.

(Step 1)
In step 1, the resin particle dispersion liquid A is prepared by curing a part of the resin particles which are the dispersoids of the resin emulsion.

The resin emulsion used as a raw material is not limited, and the dispersible resin can be widely used from water-soluble resins and solvent-based resins. For example, resins having a cyclic structure such as polyolefin-based, epoxy-based, and aromatic (for example, xylene-based and phenol-based), urethane-based, acrylic-based, vinyl acetate-based, vinyl chloride-based, and polyimide-based resins can be mentioned.

These resins can be used alone or in admixture of two or more, or may be mixed with one or more water-soluble or solvent-based resins. The water-soluble or solvent-based resin used for mixing is not particularly limited, and for example, a resin having a cyclic structure such as polyvinyl alcohol-based, polyvinyl butyral-based, epoxy-based, or aromatic (for example, phenol-based), acrylic-based resin, or the like can be used. Can be mentioned.

Considering the heat treatment in step 3 described later, the resin may not be volatilized by heating in a temperature range of 450 ° C. or higher and lower than 660 ° C. for 1 hour or more and 100 hours or less in a hydrocarbon atmosphere. preferable. This is because if the resin volatilizes during the heat treatment, defects or cracks may occur in the finally obtained organic material layer, and an intervening layer may easily be formed in the voids or the hydration resistance of the organic material layer may be lowered. Because there is. From this point of view, a thermosetting resin is preferable as the resin, and a phenolic resin is particularly preferable.

Examples of the dispersion medium of the resin emulsion include water and / or an organic solvent.

The average particle size of the dispersoid resin particles is not limited, but is preferably 5 μm or less, and more preferably 1 μm or more and 3 μm or less. The average particle size of the resin particles is a value obtained by measuring the particle size distribution on a volume basis using a particle size distribution measuring device (MT3300EXII manufactured by Microtrac Bell Co., Ltd.) and calculating the average particle size.

When the average particle size of the resin particles exceeds 5 μm, the organic material layer obtained by the heat treatment in step 3 may have voids, which may reduce the denseness of the organic material layer and lower the hydration resistance. When the average particle size of the resin particles is less than 1 μm, the value of the surface roughness Rz of the uneven portion on the surface of the organic material layer becomes small, the wettability of the coated aluminum material is lowered, or the layer containing an active material is contained. Adhesion when the (active material layer) is laminated may decrease.

The method for curing a part of the resin particles, which is the dispersoid of the resin emulsion, may be selected according to the type of resin used, and examples thereof include heating and ultraviolet (UV) irradiation. Among these means, heat treatment is the simplest. The temperature of the heat treatment is preferably 30 ° C. to 80 ° C., and if it is lower than 30 ° C., curing may be insufficient, and if it exceeds 80 ° C., not a part of the resin particles but the whole may be cured.

The curing time may be appropriately set according to the type of resin emulsion and the curing means, but is preferably within 15 days. If it exceeds 15 days, the proportion of partially cured resin particles increases remarkably, and the proportion of uncured resin decreases, which may reduce hydration resistance. The "part of the resin particles" is a part of the individual resin particles, and preferably a part of the surface of the resin particles. That is, it is preferable that when a part of the resin particles is cured, a part of the surface of the resin particles is cured, and the inside and the rest of the surface are not cured and the dispersibility is maintained.

As described above, the resin particle dispersion liquid A is obtained by curing a part of the resin particles of the resin emulsion. The resin emulsion as a raw material is also a resin particle dispersion liquid, but in the present invention, the resin particle dispersion liquid A is a term that is distinguished from the resin emulsion as a raw material.

(Step 2)
In step 2, the resin particle dispersion liquid A is applied to one side or both sides of the aluminum material to form a resin layer having uneven portions on the surface.

The aluminum material (base material) is not particularly limited, and conventionally known materials in the field of coated aluminum materials can be used. For example, pure aluminum or aluminum alloy foil or plate can be used.

The pure aluminum preferably has a purity of 98% by mass or more as measured in accordance with JIS H1303: 1976.

Examples of aluminum alloys include lead (Pb), silicon (Si), iron (Fe), copper (Cu), manganese (Mn), magnesium (Mg), chromium (Cr), zinc (Zn), titanium (Ti), Examples thereof include those containing at least one alloying element selected from the group consisting of vanadium (V), gallium (Ga), nickel (Ni) and boron (B). The aluminum material may contain unavoidable impurity elements other than the elements listed above.

As the aluminum material, those manufactured by a known method can be used. For example, a molten aluminum (including the case of an alloy) having the above-mentioned predetermined composition is prepared, and the ingot obtained by casting this is appropriately homogenized. Then, the ingot is hot-rolled and cold-rolled to obtain an aluminum foil or an aluminum plate. In the middle of the cold rolling step, an intermediate annealing treatment may be performed in the range of about 150 to 400 ° C.

The thickness of the aluminum material is not particularly limited. For example, when an aluminum foil is used, the range of 5 μm or more and 200 μm or less is generally preferable. When an aluminum plate is used, a range of more than 200 μm and 3 mm or less is preferable.

When the resin particle dispersion liquid A is applied to the surface of the aluminum material, it can be adjusted by adding water or an organic solvent to the resin particle dispersion liquid A and diluting it into a slurry or liquid state.

The coating method is not limited to the literal coating, and spray, dipping and the like can be widely used. Specifically, a spin coating method, a bar coating method, a flow coating method, a spray method and the like are appropriately adopted. After applying the resin particle dispersion liquid A, a drying treatment may be performed at a temperature of 20 ° C. or higher and 300 ° C. or lower, if necessary.

A resin layer is formed on the surface of the aluminum material by applying the resin particle dispersion liquid A. The resin layer may be formed on one side or both sides of the aluminum material, and the thickness thereof is preferably within the range of 1 mm or less, and more preferably 0.1 μm or more and 100 μm or less. If it is less than 0.1 μm, blocking may occur when a plurality of sheets are stacked or wound in a coil and subjected to heat treatment in step 3, and if it exceeds 1 mm, defects or cracks occur in the resin layer. There is a risk of The thickness of the resin layer is about 10,000 times that of the resin layer (one side in the case of double-sided formation) in the height direction, which is about 10,000 times that of the resin layer (three images taken arbitrarily). In, a straight line is drawn in parallel to the interface between the resin layer and the aluminum material and the outermost surface of the resin layer by visual judgment, and the distance between the straight lines is calculated as the thickness of the resin layer (which is the maximum thickness). It can be measured by averaging the calculated values of minutes.

In the present invention, the resin layer formed on the surface of the aluminum material has an uneven portion on the surface. When the resin particle dispersion liquid A is applied to the aluminum material, the uncured surface portion of the resin particles is integrated and formed into a film between adjacent resin particles to wet and spread on the aluminum material, and the interface between the aluminum material and the resin layer A dense resin layer is formed on the surface. However, a partially cured portion of the surface of the resin particles is prevented from forming a film by integration and remains on the resin layer while maintaining the shape of a fornix (cured portion). As a result, uneven portions in which the fornix-shaped convex portions are densely arranged are formed on the surface of the dense resin layer.

(Step 3)
In step 3, the aluminum material on which the resin layer is formed is heated in an atmosphere containing a hydrocarbon-containing substance, so that the resin layer is transformed into an organic layer containing a carbon precursor and having irregularities on the surface. And, an intervening layer containing a carbide of aluminum is formed between the aluminum material and the resin layer in at least a part region of the surface of the aluminum material.

The type of hydrocarbon-containing substance contained in the heating atmosphere is not particularly limited. For example, paraffinic hydrocarbons such as methane, ethane, propane, n-butane, isobutane, and pentane; olefinic hydrocarbons such as ethylene, propylene, butene, and butadiene; acetylene hydrocarbons such as acetylene; and these hydrocarbons. Derivatives can be mentioned.

The hydrocarbon-containing substance may be in a liquid, gas or solid state. Further, it may be present in a space (heat treatment space) in which the aluminum material on which the resin layer is formed exists, and may be introduced into this space by any method. For example, when the hydrocarbon-containing substance is in the form of a gas (methane, ethane, propane, etc.), the hydrocarbon-containing substance may be filled alone or together with an inert gas in the heat treatment space. When the hydrocarbon-containing substance is a liquid or a solid, the hydrocarbon-containing substance may be filled alone or together with an inert gas so as to be vaporized during the heat treatment in the heat treatment space. Among the hydrocarbon-containing substances, paraffinic hydrocarbons such as methane, ethane, and propane are preferable because they are originally gaseous. More preferred is at least one of methane, ethane and propane, most preferably methane.

The amount of the hydrocarbon-containing substance introduced into the heat treatment space is not limited, but a weight ratio in the range of 0.1 to 50 parts by weight in terms of carbon is preferable with respect to 100 parts by weight of the aluminum material. A weight ratio in the range of about 5 to 30 parts by weight is more preferable.

The pressure during the heat treatment is not particularly limited, and may be under normal pressure, reduced pressure, or pressurized. Further, the pressure may be adjusted at any time during the temperature rise to a certain temperature or the temperature is lowered from a certain temperature while being held at a certain temperature.

The heating temperature may be appropriately set according to the composition of the aluminum material and the like, but is usually preferably in the range of 450 ° C. or higher and 660 ° C. or lower, and more preferably in the range of 530 ° C. or higher and 620 ° C. or lower. By setting the heating temperature to 450 ° C. or higher, crystallized carbides of aluminum can be generated in the interposition layer containing aluminum and carbon. However, in the present invention, heat treatment at a temperature lower than 450 ° C. is possible, but it is preferably at least 300 ° C. On the other hand, if the heating temperature exceeds 660 ° C., the aluminum material may melt.

When the heating temperature is 400 ° C. or higher, the oxygen concentration in the heating atmosphere is preferably 1.0% by volume or less. If the heating temperature is 400 ° C. or higher and the oxygen concentration in the heating atmosphere exceeds 1.0% by volume, the thermal oxide film on the surface of the aluminum material may be enlarged and the surface resistance value of the aluminum material may increase.

The heating time is usually in the range of 1 hour or more and 100 hours or less, although it depends on the heating temperature and the like.

In the present invention, the resin layer is changed to an organic layer containing a carbon precursor and having irregularities on the surface by the above heat treatment, and at least the surface of the aluminum material is between the aluminum material and the resin layer (organic material layer). An intervening layer containing carbides of aluminum is formed in a part of the region.

The carbon precursor is a substance produced in the process of carbonizing a resin, and preferably contains at least carbon and hydrogen elements, and preferably contains a component similar to graphite or a component similar to amorphous carbon. In other words, the carbon precursor contained in the organic material layer includes an element of at least carbon and hydrogen, and the Raman shift in the Raman spectrum detected by Raman spectroscopy has a peak near 1350 cm ^-1 or around 1580 cm ^-1 Is preferable. By including such a carbon precursor in the organic material layer, conductivity can be exhibited in the organic material layer.

The intervening layer preferably contains a carbonized product of crystallized aluminum, and more preferably contains aluminum carbide. Further, the surface portion of the intervening layer may extend toward the organic substance layer in the form of fibrous, filamentous, whisker-like, plate-like, wall-like, or lump-like.

By the heat treatment in step 3, the uneven portion on the surface of the resin layer has a change in the fine portion of the uneven shape, but the shape of the uneven portion is maintained almost as it is. That is, when the resin layer changes to an organic layer while maintaining the shape of the uneven portion, a plurality of sheets are stacked or wound in a coil and subjected to heat treatment from the viewpoint of improving the manufacturing efficiency in this step. However, blocking can be prevented. Further, by forming the intervening layer in at least a part of the surface of the aluminum material, excellent adhesion between the aluminum material and the organic substance layer can be obtained.

The details of the size of the uneven portion on the surface of the organic material layer (surface roughness, T / D ratio, etc.) will be described later, but in the uneven portion, the fornix-shaped convex portions are densely arranged and the adjacent fornix-shaped convex portion is adjacent. It is preferable that the boundaries between the two are connected by recesses, and the uneven portion has a substantially flat surface. Further, it is more preferable that the recess has a continuous gradient.

In the production method of the present invention, both the resin layer and the organic substance layer do not substantially contain conductive particles (for example, aluminum particles, carbon particles, carbide particles, etc.) (do not actively add them), and therefore have excellent hydration resistance. It is possible to form a dense organic material layer, and from the viewpoint of improving production efficiency in this process, adhesion is maintained up to the central part even when a plurality of sheets are stacked or wound into a coil and subjected to heat treatment. To. However, this is not the case with respect to the trace amount of conductive particles unavoidably contained, but it is preferably 1% by weight or less.

2. Covered aluminum material The coated aluminum material of the present invention is
With aluminum material
The organic layer formed on the surface of the aluminum material and
An intervening layer formed between the aluminum material and the organic material layer,
It is a coated aluminum material provided with
(1) The intervening layer exists in at least a part of the surface of the aluminum material and contains carbides of aluminum.
(2) The organic material layer contains a carbon precursor, substantially does not contain conductive particles, and has an uneven portion on the surface of the organic material layer, and the uneven portion has a dome-shaped convex portion. It is characterized in that the concavities and convex portions that are densely arranged and adjacent to each other are connected by recesses, and the concavo-convex portions have substantially no flat surface.

The coated aluminum material of the present invention can be suitably obtained by the above-mentioned method for producing the coated aluminum material of the present invention, and a general description of the aluminum material, the organic substance layer, the intervening layer and the like can be found in the item of the manufacturing method. Same as described.

The coated aluminum material of the present invention having the above characteristics is excellent in hydration resistance because the organic material layer does not substantially contain conductive particles. Further, the surface of the organic material layer has an uneven portion, and the concave-convex portion is densely arranged with fornix-shaped convex portions, and the boundary between the adjacent fornix-shaped convex portions is connected by the concave portion. By having substantially no flat surface, the surface area is increased, which makes it excellent in wettability with a liquid electrolyte. Moreover, when the active material layer or the solid electrolyte is further laminated on the surface of the organic material layer, these adhesions are excellent. Further, even when the coated aluminum material is efficiently produced by stacking a plurality of sheets or winding them in a coil shape and subjecting them to heat treatment (heat treatment in step 3 described above), the adhesion between the aluminum material and the organic material layer is improved. It is excellent, especially in the central part of the coated aluminum material.

In addition, although FIG. 1 illustrates a mode in which the concave portion is folded back in a V shape at the deepest portion, it is preferable that the concave portion has a continuous gradient (that is, a mode in which the concave portion is folded back in an arc shape at the deepest portion). Since the recesses have a continuous gradient, the area of direct contact between the active material and the uneven portion on the surface of the organic material layer can be increased when the active material layer is laminated on the surface of the organic material layer.

In the coated aluminum material of the present invention, an intervening layer is formed between the aluminum material and the organic material layer, and this intervening layer has an effect of enhancing the adhesion between the aluminum material and the organic material layer.

Furthermore, because of heating in an atmosphere containing a hydrocarbon-containing substance, the growth of a layer containing aluminum and oxygen (natural oxide film) between the originally existing aluminum material and the organic substance layer is suppressed, and thermal expansion occurs. Since cracks occur in the layer containing aluminum and oxygen due to the influence, it is considered that the structure is such that the aluminum and the organic layer are in direct contact with each other even in a part. As a result, when the coated aluminum material is used for the electrode structure, the resistance value between the aluminum material and the organic substance layer can be reduced, and the electrode structure having a high capacitance can be manufactured. Is. In addition, since it is an organic layer that does not substantially contain conductive particles, it has a very dense structure, and in this respect as well, the adhesion is further enhanced.

Since the organic substance layer has a dense structure, it is possible to prevent the invasion of water contained in the atmosphere and suppress the hydration reaction even when exposed to a high temperature and high humidity atmosphere for a long period of time.

Further, since the organic substance layer has a dense structure, it is possible to prevent the aluminum material from being corroded by a corrosive component such as an acid used in the manufacturing process of the battery or the capacitor. With respect to such acid resistance, in a preferred embodiment, a strip-shaped coated aluminum material having a width of 10 mm and a length of 100 mm is used as a hydrochloric acid solution at 80 ± 1 ° C. at 1 M (M means a volume molar concentration [mol / L]). In an acid resistance evaluation test in which the time required for the organic material layer to be completely peeled off from the coated aluminum material was measured by immersion in, the value exceeded 400 seconds, and the acid resistance was excellent.

The thickness of the organic material layer is not particularly limited and may be appropriately set according to the intended use, but is preferably 0.1 μm or more and 1 mm or less, and more preferably 0.1 μm or more and 100 μm or less. If it is less than 0.1 μm, defects (pinholes) may occur in the organic material layer and a part of the aluminum material may be exposed, and if it exceeds 1 mm, the electric resistance in the thickness direction of the organic material layer may increase. The thickness of the organic layer is about 10,000 times that of the organic layer (one side in the case of double-sided formation) in the height direction, which is about 10,000 times that of the organic layer (three images taken arbitrarily). In, a straight line is drawn parallel to the interface between the organic material layer and the aluminum material and the outermost surface of the organic material layer by visual judgment, and the distance between the straight lines is calculated as the thickness of the organic material layer (which is the maximum thickness), and three sheets are formed. It can be measured by averaging the calculated values of minutes.

As described above, the organic layer in the present invention does not substantially contain conductive particles, but the conductivity of the organic layer can be ensured by containing a carbon precursor instead.

The size of the uneven portion on the surface of the organic substance layer can be specified, for example, by the average diameter of the fornix-shaped convex portion in a plan view. The average diameter is arbitrarily within the range of 30 μm × 30 μm from the photograph of the surface observed (observed after platinum vapor deposition on the surface) at 1000 times with a scanning electron microscope (SEM) manufactured by JEOL Ltd. All the circles (the part observed in the white circle by the secondary electrons generated at the time of measurement) that are considered to correspond to are visually selected, the maximum diameter of the circle is taken as the diameter, the total diameter is calculated, and the total is divided by the number. It is calculated from the average value.

The average diameter is not limited within the range in which the effects of the present invention are achieved, but is preferably 1 μm or more and 5 μm or less. If the average diameter is less than 1 μm, the wettability and adhesion to the active material layer may decrease due to the decrease in Rz described later. Further, when the average diameter exceeds 5 μm, the region of the concave portion between the fornix-shaped convex portions becomes large, so that there is a high possibility that a defect occurs in the dense organic substance layer, and the hydration resistance may decrease. ..

The fornix-shaped convex portion may have a substantially circular lid shape, and the average diameter of the substantially circular lid shape is observed at 1000 times by a scanning electron microscope (SEM) manufactured by JEOL Ltd. (the surface is platinum). From the photograph (observed after vapor deposition), all the approximate circles that are considered to correspond to the outer edge of the fornix-shaped convex portion within the range of 30 μm × 30 μm are visually selected, and the maximum diameter of the approximate circle is taken as the diameter. The total is calculated and calculated by the average value divided by the number.

The aggregated state of the uneven portions on the surface of the organic material layer can also be specified by the number density of the fornix-shaped convex portions in a plan view. The number density is not limited within the range in which the effect of the present invention is achieved, but is preferably 4 million pieces / cm ² or more and 100 million pieces / cm ² or less, and 5 million pieces / cm ² or more and 50 million pieces / cm. ² or less is more preferable, and 8 million pieces / cm ² or more and 30 million pieces / cm ² or less is further preferable. The number density is determined by visually selecting all particles within the range of 30 μm × 30 μm from photographs surface-observed at 1000 times with a scanning electron microscope (SEM) manufactured by JEOL Ltd., and determining the total number of particles. Is calculated by dividing by the range area.

When the number density is less than 4 million pieces / cm ² , the concave portion area becomes large by connecting the convex portions having a large average diameter. Since a dense organic layer needs to be formed in this region, there is a high possibility that defects will occur, and the hydration resistance may decrease. Further, when the number density exceeds 100 million pieces / cm ² , the Rz value described later becomes small due to the connection of the convex portions having a small average diameter, and the wettability and the adhesion to the active material layer are lowered. there is a possibility.

The uneven portion on the surface of the organic substance layer can also be specified by the surface roughness Rz (μm). The surface roughness Rz is not limited within the range in which the effect of the present invention is achieved, but is preferably 1.2 μm or more and 5 μm or less, and more preferably 1.2 μm or more and 3 μm or less. The surface roughness Rz is a value measured by a surface roughness measuring machine (model number: SURFCOM 1400D) manufactured by Tokyo Seimitsu Co., Ltd. according to the ten-point average roughness Rz of JIS B0601: 1982. The measurement speed is 0.3 mm / sec.

When the surface roughness of the uneven portion is within the above range, when a slurry containing the active material is applied to form the active material layer, it is easy to get wet as it gets wet with water, and the active material layer, the solid electrolyte and the organic substance. The contact area with the uneven portion on the surface of the layer becomes large, and sufficient adhesion can be ensured. It also has excellent wettability with liquid electrolytes.

If the surface roughness Rz of the uneven portion exceeds 5 μm, the denseness may decrease and the hydration resistance may decrease. However, the coated aluminum material of the present invention does not exclude that the surface roughness Rz of the uneven portion on the surface of the organic material layer exceeds 5 μm. When the surface roughness Rz of the uneven portion on the surface of the organic material layer is less than 1.2 μm, the contact area with the organic material layer becomes small when immersed in a liquid electrolyte or when a slurry containing an active material is applied, which is sufficient. There is a possibility that the wettability and adhesion cannot be ensured.

The uneven portion on the surface of the organic material layer is adjacent to the height (T) from the apex of the convex portion to the bottom surface of the organic material layer with the convex portion in between in an arbitrary cross-sectional view in the height direction of the organic material layer. It can also be specified by the ratio (T / D) to the distance (D) of the line segments indicating the height from the deepest part of each of the two recesses to the bottom surface of the organic substance layer (see FIG. 2). The T / D is not limited within the range in which the effects of the present invention are achieved, but is preferably 0.2 or more and 1.1 or less, and more preferably 0.3 or more and 0.8 or less.

A line segment indicating the height (T) from the apex of the convex portion to the bottom surface of the organic material layer, and the height from the deepest portion of each of the two adjacent concave portions across the convex portion to the bottom surface of the organic material layer. The distances (D) are arbitrary from the photographs of the cross section of the coated aluminum material in the height direction observed at 10000 times with an electric field radiation scanning electron microscope (FE-SEM) manufactured by Hitachi High Technologies Co., Ltd. It can be obtained from the results of visual measurement for all the convex portions within the range of 15 μm in the direction parallel to the above. Further, the T / D of the present invention is a value obtained by calculating an average value from the measured T / D of each convex portion.

The uneven portion on the surface of the organic material layer preferably has a shape of any of a polygonal weight, a cone, a hemisphere, and an ellipsoid, or a combination thereof, as the shape of the convex portion when observing the cross section. Hemispheres and / or ellipsoids are more preferred. In the case of a polygonal weight or a cone, when stress is concentrated on the apex of the convex portion, the particles may crack from that point, and debris of the organic substance layer may peel off or the hydration resistance may decrease.

With such a shape, when the active material layer is formed on the organic material layer, the area where the uneven portion on the surface of the organic material layer and the active material come into direct contact with each other becomes large, and the capacitance characteristic and the internal resistance characteristic of the capacitor become large. , Charge / discharge characteristics and life can be improved.

The uneven portion of the organic material layer formed in the present invention is formed on the surface of the organic material layer, and is not subjected to physical processing such as press processing, embossing processing, etching processing, and laser processing. When physical processing is performed, not only the surface of the organic layer but also the entire coated aluminum material is affected by the formation of uneven portions, and it becomes difficult to uniformly apply the layer containing the active material to the coated aluminum material. .. However, when the aluminum material originally has a portion having an uneven shape, it is not excluded that the organic material layer in contact has the uneven portion so as to come into contact with the aluminum material at the interface with the aluminum material.

The coated aluminum material of the present invention can be suitably used for the electrode structure or its constituent members.

Examples of the electrode structure include electrodes or current collectors of batteries or capacitors. In the present invention, when used in the applications of these electrode structures or their constituent members, since the organic material layer does not substantially contain conductive particles, chips are less likely to be generated in the cutting step of the coated aluminum material, and the chips are used. Defects such as short circuits are unlikely to occur.

When used in capacitor applications, the contact area with the layer containing electrolytes and active materials increases, leading to improved wettability and adhesion, thus improving the capacitance characteristics, internal resistance characteristics, charge / discharge characteristics, and life of the capacitor. be able to. Examples of the capacitor include an electric double layer capacitor and an aluminum electrolytic capacitor.

When used in battery applications, the contact area with the layer containing electrolytes and active materials increases, leading to improved wettability and adhesion, thus improving battery capacity characteristics, internal resistance characteristics, charge / discharge characteristics, and life. be able to. Examples of the battery include a secondary battery such as a lithium battery, a lithium ion battery, a lithium ion polymer battery, a dye-sensitized solar cell, a fuel cell, and a solid polymer fuel cell.

The coated aluminum material of the present invention will be exemplified by reference with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the coated aluminum material.

The organic material layer 2 is formed on the surface of the aluminum material 1, and the uneven portion 4 is formed on the surface of the organic material layer 2.

An intervening layer 3 is formed between the aluminum material 1 and the organic material layer 2. Further, a surface portion 5 extending from the intervening layer 3 on the organic layer side in the form of a fiber, a filament, a whiskers, a plate, a wall, a lump, or the like may be formed.

Hereinafter, the present invention will be specifically described with reference to Examples, Comparative Examples and Test Examples. However, the present invention is not limited to the examples.

Example 1
As a resin emulsion, a water-dispersible phenolic resin (solid content 40% by weight) having an average particle size of 3 μm was allowed to stand in an air environment at 40 ° C. for 5 days to cure a part of the phenolic resin particles.

This water-dispersible phenolic resin was appropriately diluted with a solvent added with 1 part by mass of isopropyl alcohol to 1 part by mass of water to prepare a water-dispersible phenolic resin ink.

This was coated on both sides of an aluminum foil having a thickness of 30 μm and a purity of 99.3% by weight of 20 cm square at 1.0 g / m ^{2 and} dried at 200 ° C. for 30 seconds to form a resin layer. The thickness of the resin layer after drying was cross-sectionally observed with an electron microscope in the same manner as in FIG. 4, and it was confirmed that the thickness was about 3 μm on one side.

After that, the aluminum foil having resin layers formed on both sides was heated in a methane gas atmosphere at 600 ° C. (oxygen concentration less than 50% by volume ppm, atmospheric pressure) for 16 hours to form a coated aluminum material on which an intervening layer and an organic substance layer were formed. Obtained.

Example 2
An aluminum foil having a width of 300 mm and a length of 500 m was produced under the same conditions as in Example 1 except that the heating process was performed in the form of a coil having an outer diameter of 179 mm wound around a steel pipe having an outer diameter of 82 mm to obtain a coated aluminum material. It was.

Example 3
The curing conditions of the phenolic resin particles in the water-dispersible phenolic resin were allowed to stand for 15 days in an air environment of 40 ° C., and 2.0 g / m ^{2 was} applied on both sides so that the thickness of the resin layer was about 6 μm on one side. A coated aluminum material was obtained by producing under the same conditions as in Example 1 except for the presence.

Example 4
As the resin emulsion, a water-dispersible phenol resin (solid content 35% by weight) having an average particle size of 4 μm, which is larger than that of Example 1, was prepared under the same conditions as in Example 1 and coated aluminum material. Got

Example 5
The resin particles of the resin emulsion were made into epoxy-based resin particles, and the water-dispersible epoxy-based resin (solid content: 30% by weight) was used under the same conditions as in Example 1 except that the thickness of the resin layer was about 2 μm on one side. It was prepared and a coated aluminum material was obtained.

Example 6
The resin particles of the resin emulsion were made into acrylic resin particles, and the water-dispersible acrylic resin (solid content 40% by weight) was used under the same conditions as in Example 1 except that the thickness of the resin layer was about 2 μm on one side. It was prepared and a coated aluminum material was obtained.

Comparative Example 1
A coated aluminum material was obtained under the same conditions as in Example 1 except that the phenolic resin particles in the water-dispersible phenolic resin were not cured.

Comparative Example 2
Carbon black particles having an average particle size of 300 nm are mixed with 1 part by mass of an epoxy resin, 20% by mass of toluene is added to the resin, and the particles are sufficiently kneaded with a kneader. A resin layer was formed on the surface of the material.

By uniformly dispersing the kneaded product containing carbon black particles having a resin layer formed on the surface in the isopropyl alcohol solution, the ink used in the carbon-containing particle adhesion step contains carbon black particles having a solid content of 20% by mass. The ink was adjusted.

This ink was applied on both sides of an aluminum foil having a thickness of 30 μm and a purity of 99.3% by weight of 20 cm square at 1.0 g / m ² each, and then dried at 200 ° C. for 30 seconds to form a resin layer. The thickness of the resin layer after drying was cross-sectionally observed with an electron microscope in the same manner as in FIG. 4, and it was confirmed that the thickness was about 1 μm on one side.

After that, the aluminum foil having resin layers formed on both sides was heated in a methane gas atmosphere at 600 ° C. (oxygen concentration less than 50% by volume ppm, atmospheric pressure) for 16 hours to form a coated aluminum material on which an intervening layer and an organic substance layer were formed. Obtained.

Comparative Example 3
The aluminum foil was 300 mm wide and 500 m long, and was manufactured under the same conditions as in Comparative Example 2 except that the heating process was performed in the form of a coil with an outer diameter of 175 mm wound around a steel pipe with an outer diameter of 82 mm to obtain a coated aluminum material. It was.

Comparative Example 4
A solvent-based phenolic resin ink was prepared by appropriately diluting the solvent-based phenolic resin with a solvent consisting of acetone, methyl ethyl ketone, and isopropyl alcohol.

This ink was applied on both sides of an aluminum foil having a thickness of 30 μm and a purity of 99.3% by weight of 20 cm square at 1.0 g / m ² each, and then dried at 200 ° C. for 30 seconds to form a resin layer. The thickness of the resin layer after drying was observed by an electron microscope in the same manner as in FIG. 4, and it was confirmed that the thickness was 1 μm on one side.

After that, the aluminum foil having resin layers formed on both sides was heated in a methane gas atmosphere at 600 ° C. (oxygen concentration less than 50% by volume ppm, atmospheric pressure) for 16 hours to form a coated aluminum material on which an intervening layer and an organic substance layer were formed. Obtained.

Comparative Example 5
Instead of the water-dispersible phenolic resin ink, the resin bead dispersion liquid (solid content) is uniformly dispersed by mixing epoxy resin beads with a solvent in which 1 part by mass of isopropyl alcohol is added to 1 part by mass of water. 40% by weight) was prepared. Using this, 2.0 g / m ^{2 was} applied on both sides, and the resin layer was prepared under the same conditions as in Example 1 except that the thickness of the resin layer to which the resin beads were attached was about 2 μm on one side. I got the wood. A schematic view of observing the cross section in the height direction is shown in FIG.

Test Example 1
The coated aluminum materials obtained in Examples 1 to 6 and Comparative Examples 1 to 5 have surface roughness Rz, hydration resistance (acid resistance), wettability (NMP contact angle), and adhesion to a layer containing an active material. I checked the sex. Further, with respect to the coated aluminum materials obtained in Example 2 and Comparative Example 3, the adhesion between the aluminum material and the organic substance layer was evaluated. These results are shown in Table 1. Further, with respect to the coated aluminum material, in the cross-sectional view in the height direction of the organic substance layer, the height (T) from the apex of the convex portion to the bottom surface of the organic substance layer and the height (T) of the two concave portions adjacent to each other with the convex portion interposed therebetween. Table 1 also shows the results of calculating the ratio (T / D) of the line segments indicating the height from the deepest part to the bottom surface of the organic substance layer to the distance (D).

Surface Roughness Coated aluminum material is pasted on a glass plate, and the surface roughness of the foil surface is measured with a surface roughness measuring machine (SURFCOM1400D, manufactured by Tokyo Seimitsu Co., Ltd.) based on JIS B 0601: 1982. It was measured with an average roughness Rz.

Moisture resistance (acid resistance)
As a test for accelerating the progress of the hydration reaction, a strip-shaped coated aluminum material having a width of 10 mm and a length of 100 mm was used at 1 M (M means volume molar concentration [mol / L]) at 80 ± 1 ° C. It was immersed in a hydrochloric acid solution, and the time until the organic substance layer was completely peeled off from the aluminum material was measured.

Based on the wettability JIS R 3257, N-methyl-2-pyrrolidone (NMP) and one drop dropped on the surface of the coated aluminum material with a syringe to measure the contact angle (°) droplets from the image observed from a horizontal direction.

Evaluation of adhesion to the layer containing the active material Adhesion between the coated aluminum material and the layer containing the active material is applied by applying a slurry of activated carbon, which is the active material used for electric double layer capacitors, to the coated aluminum material. Was evaluated. In Example 2 and Comparative Example 3, the evaluation was performed at the end portion in the width direction, which has good adhesion to the aluminum material.

<Preparation of electrodes>
Hitazol (manufactured by Hitachi Kasei Co., Ltd., GA-1015) is coated on one side of the coated aluminum material as a slurry of activated carbon with a bar coat, and dried at 100 ° C. for 2 minutes to form an activated carbon layer as a layer containing an active material. , An evaluation sample was prepared as an electrode of an electric double layer capacitor. The thickness of the activated carbon layer after drying was 11 μm.

Next, the adhesion between the activated carbon layer and the coated aluminum material was measured by the taping method. Each evaluation sample is cut into strips with a width of 20 mm and a length of 40 mm, and an adhesive tape (manufactured by Sumitomo 3M Ltd., trade name "Scotch Tape") having an adhesive surface with a width of 15 mm and a length of 70 mm is applied to the surface of the organic matter layer. After pressing with an adhesive area of 600 mm ² (15 mm × 40 mm), the coated aluminum material was peeled off, and the adhesiveness was evaluated according to the following formula.

Adhesion (%) = (W _2- W ₀ ) / (W _1- W ₀ ) x 100
W ₂ : Weight of coated aluminum material after peeling from adhesive tape (mg)
W ₁ : Weight of coated aluminum material after formation of activated carbon layer before pressing adhesive tape (mg)
W ₀ : Weight (mg) of coated aluminum material before formation of activated carbon layer
In this formula, when no peeling of the activated carbon layer is observed, the value is 100.

Evaluation of Adhesion to Organic Layer The adhesion between the aluminum material and the organic layer was evaluated by the taping method for the coated aluminum materials obtained in Example 2 and Comparative Example 3. From the core of the coiled coated aluminum material, cut out the end in the width direction (50 mm in the width direction x 20 mm in the flow direction) and the center part (50 mm in the width direction x 20 mm in the flow direction) into strips, and on the surface of the organic material layer. An adhesive tape having an adhesive surface with a width of 15 mm and a length of 70 mm (manufactured by Sumitomo 3M Ltd., trade name "Scotch Tape") is pressed against the adhesive area of 750 mm ² (50 mm x 15 mm), and then the adhesive tape is peeled off. , Adhesion was evaluated according to the following formula.

Adhesion (%) = (W _2- W ₀ ) / (W _1- W ₀ ) x 100
W ₂ : Weight of coated aluminum material after peeling (mg)
W ₁ : Weight of coated aluminum material before peeling (mg)
W ₀ : Weight (mg) of the aluminum material that is the base material of the coated aluminum material
In this formula, if no peeling of the organic layer is observed, the value is 100. The weight of the aluminum material as the base material is determined after measuring the weight of the coated aluminum material before and after peeling. Was obtained by heating in the air at 450 ° C. for 5 minutes, thermally decomposing only the organic layer, and wiping off the residue with a waste cloth.

From the results in Table 1, regarding the surface roughness Rz, in Examples 1 to 6 and Comparative Examples 2 to 3 and 5, Comparative Example 1 in which the water-dispersible phenol resin was not cured and the solvent-based phenol resin which was not an emulsion were used. It can be seen that the surface roughness Rz of the surface of the organic material layer is larger than that of Comparative Example 4 used.

Regarding hydration resistance (acid resistance), in Comparative Example 5, as shown in FIG. 5, the organic particles derived from the resin beads did not form a dense organic material layer between the particles, and thus Examples 1 to 6 It can be seen that the hydration resistance is inferior to that of Comparative Examples 1 to 4. Further, in Examples 1 to 6 and Comparative Examples 1 and 4, since it takes longer to peel off the organic substance layer as compared with Comparative Examples 2 and 3 containing carbon black particles, the organic substance layer is dense and has excellent hydration resistance. It can be said that it is. Further, in Example 3, the hydration resistance is lower than that in Examples 1 and 2, which means that in step 1, the curing time of the resin particles becomes longer, and the number of partially cured resin particles increases. This is because the density of the organic material layer is reduced due to the decrease in the proportion of the uncured resin particles.

Regarding the NMP contact angle for which the wettability was evaluated, since the surfaces of Examples 1 to 6 and Comparative Examples 2 to 3 and 5 were uneven as compared with Comparative Examples 1 and 4, N-methyl-2-pyrrolidone (NMP) was used. The contact angle shows a smaller value, and it can be seen that the wettability is good and the liquid electrolyte is easily wetted.

Regarding the adhesion between the coated aluminum material and the layer containing the active material, in Comparative Examples 1 and 4, the active material layer was almost interface-exfoliated, whereas in Examples 1 to 6 and Comparative Examples 2 to 3 and 5. Since the interfacial peeling of the active material layer is suppressed, in Examples 1 to 6 and Comparative Examples 2 to 3 and 5, since the surface has uneven portions, the contact area with the active material layer becomes large and the active material layer is active. It can be seen that the adhesion to the material layer and the solid electrolyte was improved.

Regarding the adhesion between the aluminum material and the organic material layer, in Comparative Example 3, the adhesion deteriorated in the central portion in the width direction, whereas in Example 2, almost no peeling was observed even in the central portion in the width direction. Therefore, it is considered that in Example 2, even if the material is wound into a coil and subjected to heat treatment, uniform adhesion can be ensured in the width direction.

1 Aluminum material 2 Organic layer 3 Intervening layer 4 Concavo-convex part on the surface of the organic layer 5 Surface part of the intervening layer 6 Organic particles derived from resin beads T From the apex of the convex part of the uneven part on the surface of the organic material layer to the bottom surface of the organic material layer Height D Distance between line segments indicating the height from the deepest part of each of the two adjacent recesses across the convex portion of the uneven portion on the surface of the organic matter layer to the bottom surface of the organic matter layer.

Claims (14)

With aluminum material
The organic layer formed on the surface of the aluminum material and
An intervening layer formed between the aluminum material and the organic material layer,
It is a coated aluminum material provided with
(1) The intervening layer exists in at least a part of the surface of the aluminum material and contains carbides of aluminum.
(2) The organic material layer contains a carbon precursor, does not substantially contain conductive particles, is substantially composed of a resin component and the carbon precursor, and has an uneven portion on the surface of the organic material layer. The concave-convex portion has conical convex portions that are densely arranged, and the boundary between the adjacent ellipsoidal convex portions is connected by a concave portion, and the conical convex portion has a cross section when observed. The shape of the convex portion is a polygonal weight, a cone, a hemisphere or an ellipsoid, or a combination thereof, and the uneven portion has substantially no flat surface.
A coated aluminum material characterized by that. The coated aluminum material according to claim 1, wherein the recess has a continuous gradient. The coated aluminum material according to claim 1 or 2, wherein the uneven portion has a surface roughness Rz of 1.2 μm or more and 5 μm or less. In an arbitrary cross-sectional view in the height direction of the organic matter layer, from the height (T) from the apex of the convex portion to the bottom surface of the organic matter layer and the deepest portion of each of the two adjacent concave portions across the convex portion. The method according to any one of claims 1 to 3, wherein the ratio (T / D) to the distance (D) of the line segments indicating the height to the bottom surface of the organic substance layer is 0.2 or more and 1.1 or less. Coated aluminum material. The coated aluminum material according to any one of claims 1 to 4, which is an electrode structure or a constituent member thereof. The coated aluminum material according to claim 5, wherein the electrode structure is a current collector and / or an electrode of a capacitor. The coated aluminum material according to claim 5, wherein the electrode structure is a current collector and / or an electrode of a battery. The strip-shaped coated aluminum material having a width of 10 mm and a length of 100 mm was immersed in a 1 mol / L hydrochloric acid solution at 80 ± 1 ° C., and the time required for the organic material layer to completely peel off from the coated aluminum material was measured for acid resistance. The coated aluminum material according to any one of claims 1 to 7, which has a value exceeding 400 seconds in the sex evaluation test. It is a manufacturing method of coated aluminum material.
(1) Step 1 of preparing the resin particle dispersion liquid A by curing a part of the resin particles which are the dispersoids of the resin emulsion.
(2) Step 2 of forming a resin layer having uneven portions on the surface by applying the resin particle dispersion liquid A to one side or both sides of the aluminum material.
(3) By heating the aluminum material on which the resin layer is formed in an atmosphere containing a hydrocarbon-containing substance, the resin layer is changed to an organic layer containing a carbon precursor and having uneven portions on the surface. In addition, a step 3 of forming an intervening layer containing an aluminum carbide in at least a part of the surface of the aluminum material between the aluminum material and the resin layer.
A method for producing a coated aluminum material, which comprises, in order. In the concave-convex portion, the ellipsoidal convex portions are densely arranged, and the boundary between the adjacent ellipsoidal convex portions is connected by a concave portion having a continuous gradient, and the cross section of the ellipsoidal convex portion is observed. The manufacturing method according to claim 9 , wherein the convex portion has a polygonal weight, a cone, a hemisphere or an ellipsoid, or a combination thereof, and the concave-convex portion has substantially no flat surface. .. The production method according to claim 9 or 10 , wherein the resin particles have an average particle size of 5 μm or less. The production method according to any one of claims 9 to 11 , wherein the resin layer and the organic substance layer do not substantially contain conductive particles. The production method according to any one of claims 9 to 12 , wherein the uneven portion of the organic substance layer has a surface roughness Rz of 1.2 μm or more and 5 μm or less. In an arbitrary cross-sectional view in the height direction of the organic matter layer, from the height (T) from the apex of the convex portion to the bottom surface of the organic matter layer and the deepest portion of each of the two adjacent concave portions across the convex portion. The method according to any one of claims 9 to 13 , wherein the ratio (T / D) to the distance (D) of the line segments indicating the height to the bottom surface of the organic substance layer is 0.2 or more and 1.1 or less. Production method.