JP2003338434A - Manufacturing method of aluminum material for electrolytic capacitor electrode, aluminum anode material for the electrolytic capacitor electrode, and manufacturing method of electrode material for electrolytic capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an aluminum material for an electrolytic capacitor electrode capable of producing crystal oxide or the like which are a nucleus of a sufficient etching pit in a short time without requiring accurate atmosphere control or the like, and obtaining excellent etching characteristics and a large electrostatic capacity. <P>SOLUTION: A hot extrusion and a cold extrusion are successively carried out on an aluminum slab to obtain an aluminum blank, and then, the aluminum blank is heated in contact with a heating element and annealed thereafter. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing an aluminum material for electrolytic capacitors, an aluminum anode material for electrolytic capacitor electrodes, a method for manufacturing an electrode material for electrolytic capacitors, and an aluminum electrolytic capacitor.

In this specification, the term "aluminum" is used to include its alloys, and aluminum materials include foils and plates and molded products using these.

[0003]

2. Description of the Related Art Aluminum materials generally used as electrode materials for aluminum electrolytic capacitors are
Since it is required to have a large surface area and a large capacitance per unit area, electrochemical or chemical etching treatment is performed to expand the effective area of the aluminum material. There is.

Further, for the purpose of increasing the effective area, researches have been conducted on various aspects such as material composition, manufacturing process and etching method for increasing the number of etching holes and making them thicker.

For example, in the production of an aluminum material for electrolytic capacitors in which tunnel-like pits are formed by a direct current etching method, usually, in order to develop the crystal orientation of the (100) plane, an inert atmosphere at a temperature of about 500 ° C. is used. Alternatively, final annealing is performed in vacuum. The final annealing is a step performed after finish cold rolling or after finish cold rolling and cleaning.

When crystalline oxide particles are formed on the surface of an aluminum material during the final annealing, etch pits may be generated around the crystal during electrolytic etching.
As described in Non-Patent Document 2, it is considered that generating the crystalline oxide particles on the surface of the aluminum material contributes to the improvement of electrostatic capacity.

However, as described above, in an inert gas atmosphere or a vacuum atmosphere, which is a general atmosphere for final annealing, the amount of oxygen in the atmosphere is extremely small, so that even if the final annealing is performed, it is difficult to crystallize. On the other hand, when high temperature annealing is performed in an oxidizing atmosphere, the oxide film becomes thick and the uniformity of etch pits deteriorates.

As a method for precipitating a large amount of crystals on the surface of the aluminum material, a method of blowing steam or moist air onto the surface of the aluminum material before final annealing, in the atmosphere,
A method of forming a hydration treatment film by a method of heating at a temperature of about 200 ° C., a so-called boehmite treatment method of immersing an aluminum material in heated water or an aqueous amine solution, and the like are known (Patent Document 1).

In the hydrated film, although the crystalline oxide is likely to be deposited on the surface of the aluminum material by the subsequent final annealing, since it has many Al-OH groups on the surface, it is possible to leave it in a coil state or a state in which veneers are stacked. There was a problem that adhesion was easy when batch annealing was performed. Further, in the method of heating at a temperature of about 200 ° C. in the atmosphere, precise atmosphere control such as control of the amount of water vapor is necessary to obtain the target oxide film with good reproducibility, and the aluminum foil surface is kept at the target temperature. It had the drawback of taking a long time to reach.

Further, in Patent Document 2, γ-Al is formed by continuous final annealing in an oxidizing atmosphere containing oxygen or water.
_Although a technique for precipitating ₂ O ₃ has been disclosed, the precipitation of γ-Al ₂ O ₃ may be insufficient because the final annealing time is short.

[0011]

[Non-patent Document 1] Kiyoshi Fukuoka, Nobuo Osawa, Tetsuya Motoi, Abstracts of the 95th Autumn Meeting of the Japan Institute of Light Metals p.2 65 (1998),

[0012]

[Non-Patent Document 2] Nobuo Osawa, Kiyoshi Fukuoka; Surface Technology,50
[7], 643 (1999)

[0013]

[Patent Document 1] Japanese Patent Publication No. 58-34926

[0014]

[Patent Document 2] Japanese Unexamined Patent Publication No. 63-116417 SUMMARY OF THE INVENTION The present invention has been made in view of such a technical background, and can perform processing in a short time without requiring accurate atmosphere control, and then perform the final processing. A method for producing an aluminum material for electrolytic capacitor electrodes, which is capable of producing a substance such as a crystalline oxide that becomes a nucleus of sufficient etching pits by annealing and has excellent etching characteristics, an aluminum anode material for electrolytic capacitor electrodes, and an electrode material for electrolytic capacitors An object is to provide a manufacturing method and an aluminum electrolytic capacitor.

[0015]

The present invention provides the following means. (1) Aluminum for electrolytic capacitor electrodes, characterized in that an aluminum slab is subjected to hot rolling and cold rolling in order to obtain an aluminum material, which is heated by contact with a heating body and then annealed. Method of manufacturing wood. (2) The method for producing an aluminum material for electrolytic capacitor electrodes as recited in the aforementioned Item 1, wherein the surface temperature of the heating element is 80 to 400 ° C., and the contact time between the aluminum material and the heating element is 0.001 to 30 seconds. (3) The method for producing an aluminum material for electrolytic capacitor electrodes as recited in the aforementioned Item 1, wherein the annealing is performed in an inert gas atmosphere at an aluminum body temperature of 460 to 600 ° C. (4) The method for producing an aluminum material for electrolytic capacitor electrodes as recited in the aforementioned Item 3, wherein the aluminum body temperature is 500 to 580 ° C. (5) The method for producing an aluminum material for electrolytic capacitor electrodes as described in 1 above, wherein the heating element is a hot roll. (6) The method for producing an aluminum material for electrolytic capacitor electrodes as recited in the aforementioned Item 1, wherein the aluminum material is cooled after contact with the heating body. (7) The method for producing an aluminum material for electrolytic capacitor electrodes as recited in the aforementioned Item 5, wherein the aluminum material is cooled by contact with a cooling roll. (8) The method for producing an aluminum material for electrolytic capacitor electrodes as recited in the aforementioned Item 1, wherein the purity of aluminum is 99.9% or more. (9) An aluminum anode material for electrolytic capacitors manufactured by the manufacturing method according to any one of items 1 to 8 above. (10) The aluminum anode material for electrolytic capacitors as described in 9 above, which is for medium pressure or high pressure. (11) A method for producing an electrode material for an electrolytic capacitor, which comprises etching the aluminum material produced by the production method according to any one of items 1 to 8 after annealing. (12) The method for producing an electrode material for an electrolytic capacitor as described in 11 above, wherein the etching is direct current etching.

As described above, according to the present invention, the aluminum slab is hot-rolled and cold-rolled sequentially to form an aluminum material, which is then heated by contact with a heating body and then annealed. Is characterized by.

That is, in the steps after the cold rolling, the aluminum material is heated by contact with the heating body to deposit a substance that can become an etch pit nucleus on the surface of the aluminum material by subsequent annealing. The contact heating is used as the heating method because the surface of the heating body can uniformly reach the target temperature in a short time because the surface of the heating material is relatively easy to control and can be heated rapidly and in a short time. This is because the influence of the atmosphere can be reduced.

In the production of aluminum materials for electrolytic capacitors, in order to develop the crystal orientation of the (100) plane, the final annealing is generally carried out in the temperature range of 450 to 600 ° C. in an inert atmosphere or vacuum. , A substance that can be a nucleus of an etch pit such as a crystalline oxide is not sufficiently generated. Therefore, by rapidly heating by contact heating before the final annealing, generation of a substance that can be a nucleus of an etch pit such as crystalline oxide fine particles during the final annealing is promoted.

Here, the substance that can be the nucleus of the etch pit is not only a crystalline oxide, but also an amorphous substance having a high density or a thick one, and the amorphous oxide includes a crystalline oxide and metallic aluminum. Things are included. In addition, as the type of crystalline oxide, γ-Al ₂ O ₃ and other Al ₂ O ₃ ,
Examples thereof include AlOOH including boehmite, and complex oxides with a contained metal other than aluminum (for example, Mg, Pb, Cu, etc.), but are not particularly limited to metal oxides or metal hydroxides.

It is considered that if such an oxide film on the surface of the aluminum material, which has characteristics different from those of other places, is generated, it may become a nucleus of an etch pit at the time of etching.
By rapid heating before final annealing, crystals and amorphous state before being transformed into crystals, substances containing crystals and metallic aluminum in the amorphous are generated, and these form etch pit nuclei. It is estimated that

The contact heating with the heating body is used as the rapid heating method, as described above, because the surface of the aluminum material can reach the target temperature in an extremely short time and the productivity is excellent. This is because it is possible to form a uniform oxide film in the width direction and the longitudinal direction of the aluminum coil if the temperature of the surface of the heating body that is in contact with the surface of the aluminum material is uniform because it is not easily affected by the atmosphere. .

A method of manufacturing an aluminum material for electrolytic capacitors will be described below.

The purity of the aluminum material is not particularly limited as long as it is within the range used for electrolytic capacitors.
It is preferably 9.9% or more, particularly preferably 99.95% or more. In the present invention, the purity of the aluminum material is 10
The value is obtained by subtracting the total concentration (%) of Fe, Si, Cu, Mn, Cr, Zn, Ti and Ga from 0%.

The production of the aluminum material is not limited, but is carried out in the order of adjusting the melting components of the aluminum material, slab casting, soaking, hot rolling, cold rolling, finish cold rolling (low pressure rolling), and contact heating. To be done. The (100) area ratio of the aluminum material is preferably 90% or more, and the manufacturing process conditions of the aluminum material are appropriately changed depending on the etching conditions of the aluminum material. In the middle of the rolling process, annealing (referred to as intermediate annealing) may be performed for the purpose of eliminating the distortion of the crystal structure of the aluminum material caused by the rolling in the previous process. Further, cleaning may be performed for the purpose of removing impurities and oil components on the aluminum surface in the step before the intermediate annealing.

The cleaning liquid used in the step before the intermediate annealing is not particularly limited, but an alkali aqueous solution, an acid aqueous solution, an organic solvent or the like is used.

Since the aluminum material that has undergone the rolling step has oil on its surface, it is preferable to perform cleaning before the final annealing and at least either before or after the contact heating described later, if necessary. . By carrying out such washing, the effect of contact heating is further exerted, and a large electrostatic capacitance is obtained.

After completion of rolling, contact heating is carried out without cleaning, and if large abrasion powder or the like adheres to the surface of the aluminum material, it is preferable to remove it by cleaning.

The cleaning liquid used for cleaning before or after the contact heating has a purpose of degreasing, so that a surfactant added to an organic solvent or water can be used.

As the organic solvent, a substance which does not dissolve aluminum can be used. Examples thereof include alcohol,
Examples thereof include, but are not limited to, diols, aromatic hydrocarbons such as toluene and xylene, alkane hydrocarbons, cyclohexane, ketones, ethers, esters, and petroleum products.

Examples of the above alcohol include methanol
(CH ₃ OH), ethanol (C ₂ H ₅ OH), 1-propanol (CH ₃ CH ₂
CH ₂ OH), 2-propanol (CH ₃ CH 2 (OH) CH ₃ ), 1-butanol (CH ₃ CH ₂ CH ₂ CH ₂ OH), 2-butanol (CH ₃ CH ₂ CH ₂ (OH) C
H ₃ ), 1-pentanol (CH ₃ CH ₂ CH ₂ CH ₂ CH ₂ OH), 2-pentanol (CH ₃ CH ₂ CH ₂ CH ₂ (OH) CH ₃ ), and the like, and C _n H _{2n +1} OH (n
The natural number of 1 to 10) is preferable. Also, fat-free hydrocarbons such as cyclohexanol can be used.

Examples of the above diols are 1,2-ethanediol (HOCH ₂ CH ₂ OH) and 1,2-propanediol (CH ₃ CH (O
H) CH ₂ OH) and 1,3-propanediol (HOCH ₂ CH ₂ CH ₂ OH).

Examples of the alkane hydrocarbon include pentane (C ₅ H ₁₂ ), hexane (C ₆ H ₁₄ ), heptane (C ₇ H ₁₆ ),
Octane (C ₈ H ₁₈ ), nonane (C ₉ H ₂₀ ), decane (C ₁₀ H ₂₂ ) and the like are mentioned, and those represented by C _n H _{2n + 2} (n = natural number of 5 to 15) are preferable. It is also possible to apply a dry hydrocarbon such as cyclohexane.

As an example of the above-mentioned ketone, acetone (CH ₃ COCH
₃ ), 2-butanone (CH ₃ COC ₂ H ₅ ), 3-pentanone (CH ₃ CH ₂ COC
H ₂ CH ₃ ), 3-methyl-2-butanone (CH ₃ COCH (CH ₃ ) ₂ ) and the like can be exemplified, and R ¹ COR ² (R ¹ and R ^{2 are} aliphatic hydrocarbon groups, R ¹ and R ² Those having a total carbon number of 8 or less) are preferred. Alternatively, a cyclic ketone such as cyclohexanone (C ₆ H ₁₀ O) may be used.

Examples of the above ether include R¹-O-R²(R¹Oh
And R²: Aliphatic hydrocarbon group, R ¹And R²Carbon number of
2-methoxyethanol (CH
₃OCH₂CH₂OH), 2-ethoxyethanol (CH₃CH₂OCH₂CH₂O
H), 2-butoxyethanol (CH ₃CH₂CH₂CH₂OCH₂CH₂OH)
2- (2-ethoxy) ethoxyethanol (CH₃CH₂OCH₂CH₂OCH
₂CH₂OH), and other glycol ethers are also included.

Examples of the above ester include acetic acid ester represented by CH ₃ COOR (R: an aliphatic hydrocarbon group having 1 to 5 carbon atoms).

Examples of the above petroleum products include industrial gasoline (JIS K 2201), automobile gasoline (JIS K 2202), aviation gasoline (JIS K 2206), kerosene (JIS K 2203), light oil (J
IS K2204), Aviation gasoline (JIS K 2206), Petroleum ether
(JIS K 8593), petroleum benzine (JIS K 8594), ligroin
(JIS K 8937), kerosene and the like.

As the above-mentioned organic solvent, a plurality of organic solvents may be mixed and used, and in the case of an organic solvent which can be mixed with water, it may be mixed with water as needed.

On the other hand, an anionic surfactant, a cationic surfactant, or a nonionic surfactant can be used as the surfactant contained in the cleaning liquid prepared by adding the surfactant to water used for the above-mentioned washing. .

As the anionic surfactant, a sulfate ester salt or a sulfonate salt can be used.

As the above-mentioned sulfate ester salt, R-OSO ₃ Na (R
= Saturated hydrocarbon group having 8 to 18 carbon atoms or unsaturated hydrocarbon group having one double bond), specifically sodium dodecyl sulfate (C ₁₂ H ₂₅ OSO ₃ Na), sodium hexadecyl sulfate (C ₁₆ H ₃₃ OSO ₃ Na), sodium stearyl sulfate (C ₁₈ H ₃₇ OSO ₃ Na), sodium oleyl sulfate (C ₁₈ H ₃₅ OSO ₃ Na)
₃ Na) and the like.

The above sulfonate is R-SO ₃ Na (R = carbon number 8 to 1)
8 saturated hydrocarbon group or unsaturated hydrocarbon group having one double bond) or R-SO ₃ Na (R such as sodium dodecylbenzenesulfonate (C ₁₂ H ₂₅ -C ₆ H ₄ -SO ₃ Na)) A compound represented by an alkylbenzyl group whose alkyl group is a saturated hydrocarbon group having 8 to 14 carbon atoms or an unsaturated hydrocarbon group having one double bond) can be used.

As the cationic surfactant, RN ⁺ (CH ₃ ) ₃
A quaternary ammonium salt represented by Cl ⁻ (R = saturated hydrocarbon group having 8 to 16 carbon atoms) can be used.

As the nonionic surfactant, RO-(-CH
₂ CH ₂ O) _n H (R = saturated hydrocarbon group having 8 to 16 carbon atoms or unsaturated hydrocarbon group having one double bond, n = 6 to 14) or R-
O-(-CH ₂ CH ₂ O) _n H (R = alkylphenyl group, where the alkyl group is a saturated hydrocarbon group having 8 to 12 carbon atoms or an unsaturated hydrocarbon group having one double bond, n = 6 The polyethylene glycol type nonionic surfactants represented by (14) to (14) can be exemplified.
The nonionic surfactant having n larger than the above range may be contained in a molar ratio of 50% or less.

Further, at least one or more of the above-mentioned surfactants can be added to water and used as a cleaning liquid. If the number of carbon atoms in the surfactant is less than the above range, 50
It may be added in a molar ratio of not more than%. Note that it is preferable to avoid mixing because an anionic surfactant and a cationic surfactant are mixed in water to form a precipitate.

The concentration of the surfactant added is not particularly limited, but it is preferably at least the critical micelle concentration in order to exert the cleaning effect.

In the above cleaning step, the method of contacting the aluminum material with the organic solvent or the aqueous surfactant solution used as the cleaning solution is not particularly limited, but examples include immersion, contact of the aluminum material with the surface of the cleaning solution, and spraying.

Further, for the purpose of further removing oil content and abrasion powder on the surface of the aluminum material, the aluminum material may be brought into contact with the brush or sponge during the contact between the cleaning liquid and the aluminum material and further rubbed.

In the cleaning step, the contact time between the cleaning liquid and the aluminum material is not particularly limited, but is 0.5
It is preferably not less than 2 seconds and not more than 10 minutes. If the contact time between the cleaning liquid and the aluminum material is less than 0.5 seconds, the cleaning is insufficient, and the cleaning effect reaches saturation even if the cleaning liquid is contacted for more than 10 minutes. The temperature of the cleaning liquid is preferably 5 to 60 ° C in the case of an organic solvent, and 5 to 80 ° C in the case of a cleaning liquid prepared by adding a surfactant to water. When the temperature of the cleaning liquid is below the lower limit, the cleaning power is insufficient, and the cleaning power reaches saturation even when cleaning is performed at a temperature higher than the upper limit.

After washing the aluminum material, it may be dried if necessary. As a drying method, for example, heating in air,
Inert atmosphere heating and vacuum heating can be used. When drying in air, the atmospheric temperature is preferably 200 ° C. or lower, and the drying time is preferably 10 minutes or less. Drying temperature is 200 ℃
This is because if the temperature is higher or the heating time is longer than 10 minutes, the oxide film may grow too much and the etching characteristics may deteriorate.

The aluminum material after completion of rolling or the aluminum material further cleaned after completion of rolling is contact-heated in order to generate a large number of nuclei of etch pits by subsequent annealing. The heating means may be any one capable of contact heating such as a heat roll, a heating belt, and a heating plate, but a heat roll is preferable because it is simple and can continuously perform contact heating. Also, heating may be performed on each side, or only one of the front and back sides may be heated. As the material of the heating surface of the heating element, stainless steel, plating, ceramics, Teflon resin (registered trademark), silicone resin, or the like can be freely selected, but a substance whose surface oxide film of aluminum material does not adhere to the surface of the heating element is preferable. .

The surface temperature of the heating element brought into contact with the aluminum material is preferably 80 to 400 ° C. Surface temperature of heating element is 80 ℃
If it is less than the above range, heating is insufficient, and there is a possibility that substances such as crystalline oxide fine particles that may become nuclei of etch pits during annealing performed after contact heating may be insufficiently generated. On the other hand, if the temperature is higher than 400 ° C., the oxide film becomes too thick and wrinkles may occur during cooling, which may cause operational problems. Particularly preferable heating body surface temperature is 100 to 350 ° C. A more preferable heating body surface temperature is 160 to 290 ° C.

The contact time between the surface of the aluminum material and the surface of the heating body is preferably 0.001 to 30 seconds. Contact time 0.0
If it is less than 01 seconds, the surface of the aluminum material cannot be sufficiently heated, and there is a possibility that the generation of a substance that can become an etch pit nucleus is insufficient. On the other hand, if it is longer than 30 seconds, the oxide film may become too thick and etch pits may be less likely to occur. A particularly preferred contact time is 0.01 to 10 seconds. A more preferable contact time is 0.1 to 7 seconds.

The surface temperature and contact time of the heating body may be appropriately selected in consideration of the characteristics of the oxide film on the surface of the aluminum material before contact. The contact heating atmosphere is not particularly limited, and it can be carried out in the air without special atmosphere control.

An example of a heating device using a heating roll as a heating body is a device in which at least two heating rolls are arranged in order to contact-heat the front and back surfaces of an aluminum material at a target temperature. If wrinkles occur during winding of the aluminum material after contact heating the aluminum material with a heating roll or the like, after heating with the heating roll or the like, the aluminum material is passed through a cooling body such as one or more cooling rolls. It may be configured to be cooled and then wound up. In particular, by using a cooling roll as the cooling body, it is possible to perform cooling simply and continuously. In addition, before heating the aluminum material to the target contact heating temperature with a heat roll or the like, it is possible to preliminarily raise the temperature of the aluminum material to a temperature lower than the target contact heating temperature by using another heat roll. Good.

After the contact heating, if necessary, after performing the above-mentioned cleaning, generation of a substance that can be a nucleus of an etch pit is promoted and the orientation of the crystal structure of the aluminum material is (10
Final annealing is performed mainly for the purpose of improving the etching characteristics by adjusting the orientation to 0).

Of course, after the final rolling and before the final annealing, a step other than the steps described above, such as a slit step for dividing the aluminum material coil, may be performed.

In the final annealing, the thickness of the oxide film formed on the aluminum material in the contact heating step, which is the previous step, is not excessively increased in the final annealing step so that the possibility of becoming an etching nucleus is not erased. The total thickness of the oxide film after annealing is determined by the hunter hole method (MSHunter and P. Fow
le, J. Electrochem. Soc., 101 [9], 483 (1954))
It is preferable to carry out the final annealing so that the thickness is 2.5 to 5.0 nm. Further, the (100) area ratio of the aluminum material after the final annealing is preferably 90% or more.

The treatment atmosphere in this final annealing is not particularly limited, but it is preferable to heat in an atmosphere containing less water and oxygen so as not to increase the thickness of the oxide film too much. Specifically, it is preferable to heat in an inert gas such as argon or nitrogen or in a vacuum of 0.1 Pa or less.

The method of the final annealing is not particularly limited, and may be batch annealed in a state of being wound on the coil, or may be rewound and continuously annealed and then wound on a coil. At least one of the annealing may be performed multiple times.

The temperature and time of the final annealing are not particularly limited, but for example, when performing batch annealing in the state of a coil, it is annealed at an aluminum body temperature of 460 to 600 ° C. for 10 minutes to 50 hours. Is preferred. If the aluminum body temperature is less than 460 ° C and the time is less than 10 minutes, the substance that can be the nucleus of the etch pit in the oxide film is not sufficiently generated, and the dispersed state becomes too sparse, and the etching using the crystal as the etching nucleus is performed. There is a possibility that the surface expansion effect at time cannot be expected,
This is because the crystal orientation of the (100) plane may be insufficiently developed. On the contrary, if annealing is performed at over 600 ° C, the aluminum material is likely to adhere to each other when batch annealing is performed with a coil, and even if annealing is performed for over 50 hours, the area expansion effect due to etching is saturated and conversely the heat energy cost is reduced. Cause an increase. A particularly preferred temperature is 500 to 580 ° C. for the aluminum body temperature, and the time is 20 minutes to 40 hours.

Further, the temperature rising rate / pattern of the final annealing is not particularly limited, and the temperature may be raised at a constant rate, or stepwise temperature rising / cooling may be carried out while repeating temperature rising / holding. The aluminum body temperature may be annealed in the temperature range of 460 to 600 ° C for a total of 10 minutes to 50 hours. The thickness of the aluminum material for electrolytic capacitor electrodes obtained after the final annealing is not particularly specified.

The aluminum material that has been subjected to the final annealing is
Etching is performed to improve the area expansion rate. The etching conditions are not particularly limited, but it is preferable to use the DC etching method. By the direct-current etching method, deep tunnel thick pits are formed in a portion serving as a core of the etch pits whose formation is promoted in the final annealing, a large number of tunnel pits are formed, and high capacitance is realized.

After the etching treatment, it is preferable to carry out a chemical conversion treatment to obtain an anode material, and it is particularly preferable to use it as an electrolytic capacitor electrode material for medium pressure and high voltage. Of course, it does not prevent its use as a cathode material.

An aluminum electrolytic capacitor is constructed by using the above anode material and / or cathode material as an electrode material. In this electrolytic capacitor, since the surface expansion ratio of the electrode material is increased, the electrolytic capacitor has a large capacitance.

[0065]

EXAMPLES Examples and comparative examples of the present invention will be shown below. Example 1 An aluminum material having a purity of 99.99% rolled to a thickness of 110 μm was prepared. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds and dried in air at 90 ° C. for 1 minute, and then the aluminum material is sandwiched between two stainless steel heating plates having a surface temperature of 200 ° C., Contact heating was performed in air for 2 seconds. In the state where the aluminum materials after contact heating were piled up, the actual temperature of the aluminum materials was raised from room temperature to 540 ° C at 50 ° C / h in an argon atmosphere, then kept at 540 ° C for 24 hours, and then cooled. After that, the furnace was taken out to obtain a high-purity aluminum material for electrolytic capacitors. (Example 2) Similar to Example 1, an aluminum material having a purity of 99.99% and rolled to a thickness of 110 µm was produced. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds,
After drying in air at 90 ° C for 1 minute, the surface temperature is 250.
An aluminum material was sandwiched between two heating plates made of stainless steel at 0 ° C., and contact heating was performed in the air for 2 seconds. In the state where the aluminum materials after contact heating were piled up, the actual temperature of the aluminum materials was raised from room temperature to 540 ° C at 50 ° C / h in an argon atmosphere, then kept at 540 ° C for 24 hours, and then cooled. After that, the furnace was taken out to obtain a high-purity aluminum material for electrolytic capacitors. (Example 3) Similar to Example 1, an aluminum material having a purity of 99.99% rolled to a thickness of 110 µm was produced. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds,
After drying in air at 90 ℃ for 1 minute, the surface temperature is 200
An aluminum material was sandwiched between two heating plates made of stainless steel at 0 ° C., and contact heating was performed in the air for 2 seconds. After stacking the aluminum materials after contact heating, the actual temperature of the aluminum materials was raised from room temperature to 560 ° C. at 50 ° C./h in an argon atmosphere, then kept at 560 ° C. for 24 hours, and then cooled. After that, the furnace was taken out to obtain a high-purity aluminum material for electrolytic capacitors. (Example 4) As in Example 1, an aluminum material having a purity of 99.99% and rolled to a thickness of 110 µm was produced. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds,
After drying in air at 90 ℃ for 1 minute, the surface temperature is 200
An aluminum material was sandwiched between two heating plates made of stainless steel at 0 ° C., and contact heating was performed in the air for 1 second. In the state where the aluminum materials after contact heating were piled up, the actual temperature of the aluminum materials was raised from room temperature to 540 ° C at 50 ° C / h in an argon atmosphere, then kept at 540 ° C for 24 hours, and then cooled. After that, the furnace was taken out to obtain a high-purity aluminum material for electrolytic capacitors. (Example 5) As in Example 1, an aluminum material having a purity of 99.99% and rolled to a thickness of 110 µm was produced. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds,
It was dried in air at 90 ° C. for 1 minute. Then the surface temperature 20
Prepare two heat rolls (hard chrome plating on the surface) set to 0 ° C, contact the surface of the aluminum material with the first heat roll for 1 second, and then continue to the second heat roll with aluminum. Contact heating was performed by contacting the back surface of the material for 1 second. After stacking the aluminum materials after contact heating, raise the actual temperature of the aluminum materials from room temperature to 540 ° C at 50 ° C / h in an argon atmosphere at 540 ° C.
At room temperature for 24 hours, then cooled and taken out of the furnace to obtain a high-purity aluminum material for electrolytic capacitors. (Example 6) As in Example 1, an aluminum material having a purity of 99.99% was manufactured by rolling to a thickness of 110 µm. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds,
It was dried in air at 90 ° C. for 1 minute. Next, the surface temperature
An aluminum material was sandwiched between two 90 ° C. stainless steel heating plates and contact-heated in air for 1 second. In the state where the aluminum materials after contact heating were piled up, the actual temperature of the aluminum materials was raised from room temperature to 540 ° C at 50 ° C / h in an argon atmosphere, then kept at 540 ° C for 24 hours, and then cooled. After that, the furnace was taken out to obtain a high-purity aluminum material for electrolytic capacitors. (Example 7) Similar to Example 1, an aluminum material having a purity of 99.99% and rolled to a thickness of 110 µm was produced. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds,
It was dried in air at 90 ° C. for 1 minute. Then the surface temperature 38
Prepare two heat rolls (hard chrome plating on the surface) set to 0 ℃, contact the first heat roll with the aluminum material surface for 0.1 seconds, and then continue to the second heat roll with aluminum. Contact heating was performed by heating the back surface of the material for 0.1 seconds. In the state where the aluminum materials after contact heating were piled up, the actual temperature of the aluminum materials was raised from room temperature to 540 ° C at 50 ° C / h in an argon atmosphere, then kept at 540 ° C for 24 hours, and then cooled. After that, the furnace was taken out to obtain a high-purity aluminum material for electrolytic capacitors. (Example 8) As in Example 1, an aluminum material having a purity of 99.99% and rolled to a thickness of 110 µm was produced. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds,
It was dried in air at 90 ° C. for 1 minute. Then the surface temperature 25
Prepare two heat rolls (hard chrome plated on the surface) set to 0 ° C, contact the surface of the aluminum material with the first heat roll for 0.005 seconds, and then continue to the second heat roll with aluminum. Contact heating was performed by contacting the back surface of the material for 0.005 seconds. In the state where the aluminum materials after contact heating were piled up, the actual temperature of the aluminum materials was raised from room temperature to 540 ° C at 50 ° C / h in an argon atmosphere, then kept at 540 ° C for 24 hours, and then cooled. After that, the furnace was taken out to obtain a high-purity aluminum material for electrolytic capacitors. (Example 9) As in Example 1, an aluminum material having a purity of 99.99% and rolled to a thickness of 110 µm was produced. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds,
After drying in air at 90 ℃ for 1 minute, the surface temperature is 150
An aluminum material was sandwiched between two heating plates made of stainless steel at 0 ° C., and heated in air for 30 seconds. In the state where the aluminum materials after contact heating were piled up, the actual temperature of the aluminum materials was raised from room temperature to 540 ° C at 50 ° C / h in an argon atmosphere, then kept at 540 ° C for 24 hours, and then cooled. After that, the furnace was taken out to obtain a high-purity aluminum material for electrolytic capacitors. (Example 10) As in Example 1, an aluminum material having a purity of 99.99% and rolled to a thickness of 110 µm was produced. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds,
After drying in air at 90 ℃ for 1 minute, the surface temperature is 200
An aluminum material was sandwiched between two heating plates made of stainless steel at 0 ° C., and contact heating was performed in the air for 2 seconds. After stacking the aluminum materials after contact heating, the actual temperature of the aluminum materials was raised from room temperature to 480 ° C. at 50 ° C./h in an argon atmosphere, then kept at 480 ° C. for 24 hours, and then cooled. After that, the furnace was taken out to obtain a high-purity aluminum material for electrolytic capacitors. (Example 11) Similar to Example 1, an aluminum material having a purity of 99.99% and rolled to a thickness of 110 µm was produced. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds,
After drying in air at 90 ℃ for 1 minute, the surface temperature is 200
An aluminum material was sandwiched between two heating plates made of stainless steel at 0 ° C., and contact heating was performed in the air for 2 seconds. After stacking the aluminum materials after contact heating, raise the actual temperature of the aluminum materials from room temperature to 580 ° C at 50 ° C / h in an argon atmosphere, hold at 580 ° C for 24 hours, and then cool. After that, the furnace was taken out to obtain a high-purity aluminum material for electrolytic capacitors. (Example 12) A high-purity aluminum material for electrolytic capacitors was obtained in the same manner as in Example 1 except that after the contact heating, the step of cooling the aluminum material by sandwiching it between stainless steel plates having a surface temperature of 10 ° C for 10 seconds was performed. . (Comparative Example 1) As in Example 1, an aluminum material having a purity of 99.99% rolled to a thickness of 110 µm was produced. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds,
After drying in air at 90 ° C for 1 minute, the solid material temperature of the aluminum material is increased from room temperature under an argon atmosphere in a stacked state.
After the temperature was raised to 540 ° C at 50 ° C / h, it was kept at 540 ° C for 24 hours, then cooled and taken out of the furnace to obtain a high-purity aluminum material for electrolytic capacitors. (Comparative Example 2) As in Example 1, an aluminum material having a purity of 99.99% and rolled to a thickness of 110 µm was produced. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds,
After drying in air at 90 ° C for 1 minute, the solid material temperature of the aluminum material is increased from room temperature under an argon atmosphere in a stacked state.
After the temperature was raised to 480 ° C at 50 ° C / h, it was kept at 480 ° C for 24 hours, then cooled and taken out of the furnace to obtain a high-purity aluminum material for electrolytic capacitors. (Comparative Example 3) As in Example 1, an aluminum material having a purity of 99.99% rolled to a thickness of 110 µm was produced. The obtained aluminum material is dipped in an alkane hydrocarbon for 2 seconds,
After drying in air at 90 ° C for 1 minute, the solid material temperature of the aluminum material is increased from room temperature under an argon atmosphere in a stacked state.
After heating up to 580 ° C. at 50 ° C./h, it was kept at 580 ° C. for 24 hours, then cooled and taken out from the furnace to obtain a high-purity aluminum material for electrolytic capacitors. After the aluminum materials obtained in the above Examples and Comparative Examples were dipped in an acid, hydrochloric acid-
After electrolytic etching with a sulfuric acid aqueous solution, the pit diameter was enlarged by further immersing in an acid solution to obtain an etched foil. The obtained etched foil was subjected to a chemical conversion treatment at a chemical conversion voltage of 270 V according to the EIAJ standard to obtain a capacitance measurement sample.

Table 1 shows the contact heating conditions, the actual temperature of the aluminum material at the time of annealing, and the capacitance evaluation of Examples and Comparative Examples. The capacitance evaluation shows a value when Comparative Example 1 is set to 100.

[0067]

[Table 1]

As can be seen from Table 1 above, in the embodiment,
By performing contact heating using a heating plate or a heat roll before annealing, the electrostatic capacity is improved as compared with Comparative Examples 1 to 3 in which contact heating is not performed.

[0069]

According to the present invention, according to the above, the aluminum foil is heated by contact with a heating body after cold rolling and then annealed, whereby a large amount of a substance that can be a nucleus of an etch pit is deposited on the foil surface. It is possible to manufacture an aluminum foil for electrolytic capacitors having excellent characteristics. In particular, since contact heating is used as the heating method, it is possible to reach the target temperature on the aluminum foil surface evenly in a short time, so temperature control is relatively easy, and heating can be performed quickly and in a short time. The influence of the atmosphere can be reduced. Therefore, by etching this aluminum foil for electrolytic capacitors, the etching is effectively performed at the position where the substance that can be the core of the etch pit exists, and as a result, the surface expansion rate can be improved, which in turn increases the capacitance. The electrolytic capacitor electrode material can be used.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01G 9/04 304 C22F 1/00 606 // C22C 21/00 613 C22F 1/00 606 623 613 661Z 623 682 661 683 682 685Z 683 686B 685 691A 686 691B 691 691C H01G 9/04 346 9/24 B (72) Inventor Kazuhiro Kodama 6-224, Kaiyamacho, Sakai City, Osaka Prefecture Showa Denko Co., Ltd. Sakai Office (72) Inventor Yutaka Kato 6-224 Kaiyama-cho, Sakai-shi, Osaka Inside Showa Denko Co., Ltd. Sakai Works (72) Inventor Masashi Sakaguchi 6-224, Kaiyama-cho, Sakai-shi, Osaka Showa Denko Co., Ltd.

Claims (12)

[Claims] 1. An electrolytic capacitor electrode characterized in that an aluminum slab is subjected to hot rolling and cold rolling in order to obtain an aluminum material, which is then heated by contact with a heating body and then annealed. For manufacturing aluminum materials for automobiles. 2. The surface temperature of the heating element is 80 to 400 ° C., and the contact time between the aluminum material and the heating element is 0.001 to 30.
The method for producing an aluminum material for an electrolytic capacitor electrode according to claim 1, which is second. 3. Annealing is carried out at an aluminum body temperature of 460-6.
The method for producing an aluminum material for electrolytic capacitor electrodes according to claim 1, which is carried out at 00 ° C. in an inert gas atmosphere. 4. The aluminum body temperature is 500 to 580.
The method for producing an aluminum material for an electrolytic capacitor electrode according to claim 3, wherein the temperature is at 0 ° C. 5. The method for producing an aluminum material for an electrolytic capacitor electrode according to claim 1, wherein the heating body is a hot roll. 6. The method for producing an aluminum material for an electrolytic capacitor electrode according to claim 1, wherein the aluminum material is cooled after the contact with the heating body. 7. The method for producing an aluminum material for an electrolytic capacitor electrode according to claim 5, wherein the aluminum material is cooled by contact with a cooling roll. 8. The method for producing an aluminum material for an electrolytic capacitor electrode according to claim 1, wherein the purity of aluminum is 99.9% or more. 9. An aluminum anode material for an electrolytic capacitor manufactured by the manufacturing method according to claim 1. 10. The aluminum anode material for electrolytic capacitors according to claim 9, which is for medium or high pressure. 11. A method of manufacturing an electrode material for an electrolytic capacitor, which comprises subjecting an aluminum material manufactured by the manufacturing method according to claim 1 to etching after annealing. 12. The method for producing an electrode material for an electrolytic capacitor according to claim 11, wherein the etching is direct current etching.