WO2000065672A1

WO2000065672A1 - Battery case and surface treated steel sheet for battery case

Info

Publication number: WO2000065672A1
Application number: PCT/JP2000/002602
Authority: WO
Inventors: Hitoshi Ohmura; Tatsuo Tomomori; Hideo Ohmura; Tatsuya Ohshima
Original assignee: Toyo Kohan Co., Ltd.
Priority date: 1999-04-23
Filing date: 2000-04-20
Publication date: 2000-11-02
Also published as: AU3841100A; JP3678347B2

Abstract

A high-quality battery case excellent in continuous formability, and a surface-treated steel sheet suitably used for producing the battery case. The battery case is obtained by forming, on the inner and outer surfaces of a blank sheet consisting of a steel sheet, surface-treated steel sheets each having a dull-finish nickel plated layer by a DI or DTR forming method. Because of its significantly reduced powdering feature, the dull-finish nickel plated layer requires a lower punch load in a cupping process and can minimize metal contact-caused flaws in a die and punch to thereby elongate a metal die life and enhance a continuous productivity of a battery case.

Description

Description Battery case and surface-treated steel sheet for battery case ζ 'Technical field

The present invention relates to a container for enclosing an alkaline liquid, and more particularly to a battery case such as an alkaline manganese battery or a nickel-cadmium battery, and a surface-treated steel sheet for a battery case that can be suitably used for manufacturing the case.

10m landscape technology

Conventionally, cold-rolled steel strips are press-formed into battery cases for battery cases in which strong alkaline liquids such as alkaline manganese batteries and nickel cadmium batteries are sealed, and then barrel-plated or nickel-plated steel strips are pressed into battery cases. Have been adopted. As described above, nickel plating is used for battery applications such as alkaline manganese batteries and nickel cadmium batteries because these batteries mainly use a strong alkaline water-repellent electrolyte as an electrolytic solution, so that they are resistant to alkaline corrosion. When nickel is connected to external terminals, nickel has a stable contact resistance when connected to external terminals.Moreover, when batteries are manufactured, each component is welded and assembled into batteries. Spot welding is performed, but nickel has the advantage of excellent spot weldability.

By the way, in recent years, the barrel plating method is difficult to apply nickel plating evenly, especially on the inner surface of the case, and the plating thickness varies widely. The pre-plating method has become the mainstream. In addition, also in the pre-plating method, in order to mainly improve corrosion resistance, a method of performing a heat diffusion treatment after nickel plating has been applied.

On the other hand, the relationship between the battery performance of alkaline manganese batteries and the positive electrode case (battery case) There is a relationship between the performance of the battery and the properties of the inner surface of the positive electrode case, and the positive electrode mixture for alkaline manganese batteries (manganese dioxide as the positive electrode active material, graphite as the conductive agent, and the hydroxide power of the electrolyte) It is said that the lower the contact resistance with the better, the better the battery performance. In the case of alkaline manganese batteries, the positive electrode mixture contacts the positive electrode case

The positive electrode case is a conductor that exchanges electrons with the battery container. Therefore, when the contact resistance between the positive electrode mixture and the inner surface of the positive electrode case is high, the internal resistance of the battery increases, resulting in a decrease in the operating voltage and a decrease in the discharge duration, which impairs the battery performance. Therefore, it is desired to reduce the contact resistance between the positive electrode mixture and the inner surface of the positive electrode case. Therefore, in order to reduce the contact resistance between the positive electrode mixture and the positive electrode case,

! 0 There have been proposed methods of roughening the surface roughness of the inner surface of the electrode case, forming grooves in the vertical direction of the positive electrode case, and applying a conductive agent obtained by adding a binder to conductive paint or graphite.

Furthermore, in recent years, instead of the multi-stage deep drawing method to increase the battery capacity as a press forming method for a battery case, a DI (draw ng an dironing) forming method has been used as a method for reducing the thickness. (See Japanese Patent Publication No. 7-99686). This DI molding method and DTR (draw ingthin and redr aw) molding method allow the positive electrode and negative electrode active material to be filled in as much as the case side wall thickness is smaller than the bottom surface thickness, and increase the battery capacity, Since the case bottom is thick, there is an advantage that the pressure resistance of the battery can be improved.

By the way, as mentioned above, the DI molding method and the DTR molding method are effective molding methods for increasing the battery capacity.On the other hand, in terms of moldability, compared with the conventional multistage deep drawing method, Since the material has high deformation resistance, it has an adverse aspect in continuous formability.

Specifically, if the powdering properties (powdering of the plating layer) in the cutting process of the DI molding method or the DTR molding method are poor, they adhere to the die and punch in the ironing process, and as a result, flaws are formed on the case side wall. Will happen. This phenomenon is caused by deep drawing However, the DI molding method and the DTR molding method have a smaller surface roughness on the case wall and a glossier appearance, so the above-mentioned flaws are more noticeable, and However, DI molding and DTR molding are more important. In addition, since the contact surface pressure between the material and the tool is higher in the DI forming method and the DTR forming method than in the draw forming, good lubricity is required from the viewpoint of tool life. Therefore, from the material aspect, a material having good padding properties and good press lubricant retention is required.

First, as a means for improving the retention of lubricant by using a nickel-plated steel sheet, it is conceivable that cracks are generated in the plating layer during press forming, and the lubrication is maintained at the cracks. As a means for achieving this, bright nickel plating, in which the plating layer has a high hardness, is generally conceived. However, the bright nickel-plated single layer has a disadvantage that, although the light-coated layer is hard, it has a brittle property and is inferior in powdering property at the time of press molding. In addition, on the outer surface of the battery case, cracks occur in the bright nickel plating single layer due to processing, and the corrosion resistance is poor due to the exposure of iron at the cracks.として As a method of improving the corrosion resistance, a method of performing bright nickel plating on matte nickel plating is considered. However, in order to obtain effective glossiness (smoothness), the bright nickel plating layer must be thickened or a large amount of expensive brightener must be added to increase the glossiness, but the cost increases. . In addition, sulfur-containing organic additives (for example, sulfones with = c-so ₂ — groups) to reduce the size of

^ 0 acid, etc.), ironing in DI molding and DTR molding, and an increase in material temperature in the stretching process promotes embrittlement due to sulfur, further deteriorating powdering resistance.

In view of this, the present inventors have studied various battery case materials having excellent moldability and battery performance in the DI molding method and the DTR molding method from such a viewpoint. It has been found that the bright nickel plating layer shows excellent characteristics in padding resistance. After nickel plating, temper rolling may be performed. Temper rolling increases the gloss and improves the appearance. For example, a sample whose glossiness after semi-bright nickel plating (JISZ8741, specular glossiness measurement method) was 900, was subjected to temper rolling at a rolling rate of 0.5%, Increases to 960. In addition, the corrosion resistance of the processed part is the same without being deteriorated by temper-rolling.

The present invention has been made based on such knowledge, and has been made of a battery case having high quality and excellent continuous formability, and a surface-treated steel sheet which can be suitably used for manufacturing the battery case. Making it a technical issue.

10 Disclosure of the invention

The battery case of the present invention has a semi-bright nickel plating layer formed on the inner surface of the battery case, a semi-bright nickel plating layer formed on the lower layer, and a bright nickel plating layer formed on the upper layer, on the outer surface of the battery case. It is characterized by being.

The battery case of the present invention is characterized in that a semi-bright nickel plating layer is formed on the inner and outer surfaces of the battery case.

In the battery case of the present invention, a matte nickel plating layer is formed on the inner surface of the battery case, a semi-bright nickel plating layer is formed on the lower layer on the outer surface of the battery case, and a bright nickel plating layer is formed on the upper layer. It is characterized by having been done.

The battery case of the present invention is characterized in that a matte nickel plating layer is formed on the inner surface of the battery case, and a semi-gloss nickel plating layer is formed on the outer surface of the battery case.

The battery case of the present invention is characterized in that it is obtained by forming a surface-treated steel sheet having a nickel-plated nickel-plated layer formed on at least one surface of an original plate made of a steel sheet by a DI forming method or a DTR forming method. I do.

^ The surface-treated steel sheet for a battery case of the present invention has a semi-gloss nickel plating layer formed on the inner side of the battery case and a semi-glossy lower layer on the outer side of the battery case. A nickel plating layer is formed, and a bright nickel plating layer is formed on an upper layer.

The surface-treated steel sheet for a battery case according to the present invention is characterized in that a semi-bright nickel plating layer is formed on the side that becomes the inner and outer surfaces of the battery case.

^ The surface-treated steel sheet for a battery case of the present invention has a matte nickel plating layer formed on the inner side of the battery case and a semi-bright nickel plated layer formed on the lower side of the battery case outer side. And a bright nickel plating layer is formed on the upper layer.

The surface-treated steel sheet for a battery case of the present invention has a matte nickel plating layer formed on the inner surface of the battery case, and a semi-bright nickel plated layer formed on the outer surface of the battery case. It is characterized by the following.

In the surface-treated steel sheet of the present invention, the semi-bright nickel-plated layer contains one or more of unsaturated carboxylic acid formaldehyde, polyoxy-ethylene adduct, nitrogen-containing complex compound, or nitrogen-containing aliphatic compound as a brightener. It is characterized in that it is formed using a plating bath. BEST MODE FOR CARRYING OUT THE INVENTION

Regarding the generation of semi-bright nickel plating on the above-mentioned battery case and surface-treated steel sheet, if a semi-brightener that does not contain a sulfur-containing organic additive is added to a watt bath or a sulfamic acid bath, the semi-brightener becomes nickel and As a result, the elongation of the eutectoid plating layer and the increase in the content of the semi-brightener in the coating film increase the hardness of the plating film layer. Specifically, the plating surface hardness of the nickel sulfate bath is about 340 to 370 (pickas hardness) when the semi-brightening agent is not added, whereas the semi-brightening agent is 2 to 3 cc. / 1 / When added, it becomes as high as about 350 to 420 (picker hardness).

The semi-bright nickel-plated steel sheet is manufactured in this manner, and the semi-bright nickel-plated steel sheet is formed by a DI forming method and a DTR forming method to form a battery case ( Alkaline manganese battery LR6 type) was fabricated.

In addition, in order to check the powdering properties, the prepared battery case was removed with an organic solvent to remove the lubricant on the inside and outside surfaces of the case, and the powder with the plated layer was attached to the cellophane tape. 25 times), the powdering properties

^ It was confirmed that it was significantly reduced.

Furthermore, in order to check the continuous formability of the battery case, the powdering properties were measured by three methods, namely, the deep drawing method, the DI method, and the DTR method. As a result, they found that the surface-treated steel sheet having the semi-bright nickel-plated layer according to the present invention had a lower punch load than the bright nickel-plated single-layer steel sheet.

¹⁰ As described above, the punch load when the surface-treated steel sheet according to the present invention is formed is lower than that of the bright nickel-plated single layer because it does not contain the sulfur-containing semi-brightening agent. It is considered that in the ironing process of DI molding and the stretching process of DTR molding, the frictional resistance is reduced and the punch load is reduced. As a result, the punch load is reduced and the die and punch flaws are generated due to metal contact.

\ 5 It is a great advantage that the mold life is extended and the continuous productivity of the battery case is improved because the production is suppressed. Next, the low frictional resistance is favorable for the battery case removability (stripping property), which is an important factor in DI formability and DTR formability.

The present invention is not limited to the DI molding method Ud or DTR molding method as means for thinning the case wall of the battery case, and the powdering property can be improved by the conventional multi-stage deep drawing method, It can be suitably used.

The semi-brightening agent for the sulfur-free semi-bright nickel plating bath is a mixture of a nitrogen-containing heterocyclic compound and a nitrogen-containing aliphatic compound, polyoxy-ethylene adduct of unsaturated alcohol or unsaturated carboxylic acid formaldehyde alone or two or more Is the mixture of good. The total amount of the semi-brightening agent is preferably in the range of 0.3 to 10 cc / 1. If the amount of semi-brightener added is less than 0.3 cc / l, the powdered anti-powder When the amount of semi-brightening agent exceeds 10 cc / 1, on the other hand, the smoothness effect, which is a measure of the glossiness of the surface-treated steel sheet, reaches saturation and the semi-brightening agent is not used. It is expensive because it is expensive.

The plating thickness of the surface-treated steel sheet of the present invention ranges from 0.5 to 3. for the semi-bright nickel plating on the inner surface side of the case, and 1.0 for the total nickel plating thickness on the outer surface side of the case. A range of ~ 4.0 m is desirable. When the thickness of the inner surface of the case is less than 0.5 zm, in the case of batteries such as alkaline manganese batteries, the iron exposure of the steel base is large, the corrosion is poor, and the deterioration of the battery performance due to the elution of iron ions into the electrolytic solution may occur. Because it wakes up. On the other hand, if the plating thickness on the outer surface of the case is less than 1.0 O ^ m, the corrosion resistance 10 is not sufficient, and due to the occurrence of cracking during the battery case pressing process, battery manufacturing process and long-term storage, 1.0 im or more is obtained. Because it is necessary.

The upper limit (3.0 m, 4.0 xm) of the plating thickness on the inner and outer surfaces of the case is, respectively, when the plating thickness is larger than these values, the effect has reached saturation and it is not possible to increase the thickness further. Because it is an economy.

Normally, low carbon Almikild steel is suitably used as the base steel of the 15 "surface treated steel sheet, that is, the plating base sheet. In addition, niobium and titanium are added, and the non-aging ultra-low carbon steel (carbon Cold rolled steel strip manufactured from less than 0 1%) is also used.The steel strip that has been cold rolled, electrolytically cleaned, annealed, and temper rolled is used as the original plate after cold rolling. Semi-bright nickel plating is performed on the original plate to produce a surface treated steel sheet.After plating, temper rolling may be performed.

The plating bath may be any of a known sulfuric acid bath and a sulfamic acid bath, but a sulfuric acid bath, which is relatively easy to manage, is suitable.

Example

The present invention will be further specifically described with reference to the following examples.

^ Cold-rolled, annealed, and temper-rolled low-carbon aluminum-killed steel sheets with a thickness of 0.25 mm and 0.4 mm were used as the base plates for plating, respectively. The chemical composition of the steel of both plating base sheets is Both are as follows.

C: 0.04% (% is weight%, the same applies hereinafter)

Mn: 0.22%

S i: 0.0 1%

5 "P: 0.012%

S: 0.06%

A1: 0.048%

N: 0.0 0 25%

The plated original plate was subjected to alkaline electrolytic degreasing, water washing, sulfuric acid immersion, and water washing by a conventional method (after pretreatment of D, and then semi-bright nickel plating under the following conditions to produce a surface-treated steel plate.

1) Semi-bright nickel plating

It was prepared by adding a semi-brightener to the following nickel sulfate bath.

Bath composition

1 ^ Nickel sulfate NiSCV6H ₂₀ 320 g / 1

Nickel chloride NiCl ₂ '6H ₂ 0 10 g / 1

Boric acid H ₃ B0 ₃ 40 gl 1

Bath pH: 4 (adjusted with sulfuric acid)

Stirring: Air stirring

0 Bath temperature: 60

Cathode current density: 10 A / dm ²

Anode: S pellets (product name, spherical, manufactured by INCO) are loaded into a titanium basket and covered with a polypropylene bag.

As the semi-brightening agent, an unsaturated carboxylic acid formaldehyde or a polyoxyethylene adduct was used. Under the above conditions, the glossiness and the plating thickness were changed by changing the addition amount of the semi-brightener and the electrolysis time. 2) Bright nickel plating

A brightening agent was added to the sulfuric acid Nigel bath to perform a glossy Nigel plating. A benzenesulfonic acid derivative was used as a sulfur-containing brightener, and a mixture of a nitrogen-containing complex compound and a nitrogen-containing aliphatic compound was used as a sulfur-free brightener.

^ Bath composition

Nickel sulfate NiS0 ₄ '6H ₂ 0 300 gl 1

Boric acid H ₃ B0 ₃ 45 gl 1

Bath temperature: 50 X:

Cathode current density: 10 A / dm ²

ID Anode: S pellets (product name, spherical, manufactured by INCO) are loaded in a titanium basket and covered with a polypropylene bag.

Under the above conditions, the plating thickness was changed by changing the amount of brightener and the electrolysis time. After performing the above semi-bright nickel plating and bright nickel plating, the plating thickness and the plating film alloy composition and the plating layer were dissolved in 3% nitric acid and analyzed by ICP (inductively coupled plasma emission spectroscopy). The plating thickness was determined by dividing the amount of each dissolved element by the plating area and taking the specific gravity of each element into account. Table 1 shows the results. In Table 1, the unsaturated carboxylic acid formaldehyde as brightener or semi-brightener is A, the polyoxymonoethylene adduct is B, the mixture of the nitrogen-containing heterocyclic compound and the nitrogen-containing aliphatic compound is C, Benzenesulfonic acid derivatives are indicated by a D in each case. In addition, the rolling ratio of Example 8 and Example 11 was reduced to 0.

A temper rolling of 5% was performed.

(Battery case fabrication)

The battery case is formed by the DI molding method using the above-mentioned plated steel sheet having a thickness of 0.4 mm, cutting from a blank diameter of 41 mm to a diameter of 20.5 mm, and then redrawing with a DI molding machine. And two-stage ironing was performed to form an outer diameter of 13.8 mm, a case wall of 0.20 mm, and a height of 56 mm. Finally trim the upper part, height 4 A 9.3 mm LR 6 type battery case was fabricated.

On the other hand: For the production of the battery case by the DTR molding method, using a plated steel plate with a thickness of 0.25 mm, punching into a blank diameter of 58 mm, several times drawing and redrawing, the outer diameter is 13.8 mm, and the case An LR6 type battery case with a wall thickness of 0.20 mm and a height of 49.3 mm was fabricated.

(Padding performance evaluation)

The evaluation of the powdering property is based on the powdering before and after the molding in the process of manufacturing the battery case, that is, blanking → cutting → degreasing-weight measurement (1)-molding-degreasing-weight measurement (2). The sex was evaluated. The degreasing was carried out by ultrasonic cleaning with acetone following degreasing with dipping in Alθθ. Since the weight loss has a large error in the measurement of each case, the measurement was repeated three times using 30 cases as a unit of measurement. The results are shown in Table 1.

As is clear from Table 1, in the comparative example, the amount of the dropped powder was as large as 170 to 180 mg / 30 cases, whereas Examples 1 to 12 of the present invention were not. , | 5- In all cases, the amount of powder shed is as small as 20 to 3 lmg / 30 cases. This indicates that the battery case according to the present invention has excellent powdering properties.

Plate thickness Nickel plating type Powder Example Ring or can inner surface ¾ cr i? ^ 1

δ ^^ δ e

Comparative Example or 'Type of'

(DO) te Outer surface (cc / L) ¾ 30 cans) Inner surface Semi-gloss A 0-5ceA and B 0.5 0.5

cc / L

0.40 DI molding 30

Upper layer Glossy C 0.5 0.5 Outer surface

Lower layer with semi-gloss A 0.5cc / Li: B 0.5 0.5

cc / Shinominato

Perform ^) 面 side Semi-gloss A 0.6 1.0

Two

0.25 Upper layer: glossy A and C 3cc / L 0.6 DTO 25 outer molding Lower layer: semi-gloss A 0.6 1.0 mm m inner semi-gloss B 0.3 2.0

Three

0.40 Upper layer Glossy B ^ and C 2cc / L 15W molding 22 Outer surface

o

Lower layer Semi-gloss B 0.3 1.5 Actual: S Example Inner surface Semi-gloss B 0.6 2.5

Four

0.25 ± «: Glossy A lcc / L, B J c / L 2.028 With outer surface. L's elder 4

Lower layer semi-gloss mets B 0.6 2.0 real fine inner semi-sawa mets A 5 3.0

Five

0.40 MB: Gloss, Mitsutsuki 0.5 W molding 30 outer surface

Employee: Semi-gloss finish A 5 3.0 Inside Semi-gloss finish A 2 0.5

D 0.40 DI molding 24 Outer surface Semi-gloss A 2 1.0

Inner surface Semi-gloss B 0.3 1.0

7 0.25 T 21 Outer surface Semi-gloss B 0.3 2.0

Examples In ia Semi-gloss A Noshito B 5cc / L 2.0

8 0.40 no Okina 4 r ii External half-gloss with 3.0

Example Inner surface Semi-gloss 2.5

9 0.25 Λ 1.5 .n Semi-gloss outer surface 3.5

Internal semi-gloss 3.0

Real ^½ 0. 0 B 5 DI molding 31

Outer surface Semi-gloss 4.0

Actual Jeong 倂 inside. Surface matte plating 3.0

0.40 W molding 25 Outer surface Semi-gloss B 5 4.0

Implementation Inside matte finish 2.0

0.0

± β: glossy 4.0 DI molding 28 outer surface

Lower layer: glossy Β 5 3.0 Comparative Example Inside Glossy D 5 1.8

0.40 DI molding 170 External glossy D 5 1.9

Comparison ¾1 Inner surface Matte 2.0

2 0.0

Upper layer: glossy D 5 4.0 DI molding 180 outer surface

Lower layer: matte finish 1.0 Industrial applicability

The battery case of the present invention is characterized in that the semi-bright nickel plating layer does not contain a sulfur-containing semi-bright agent. Here, semi-bright nickel plating can significantly reduce the powdering property, lower the punch load in the cutting process, suppress die and punch flaws due to metal contact, and extend die life. Therefore, the continuous productivity of the battery case can be improved.

Claims

The scope of the claims

1. A battery case in which a semi-bright nickel plating layer is formed on the inner surface of the battery case, and a semi-bright nickel plating layer is formed on the lower surface of the battery case, and a bright nickel plating layer is formed on the upper layer.

2. A battery case with a semi-bright nickel plating layer formed on the inside and outside of the battery case.

3. The battery case has a matte nickel plating layer on the inner surface of the battery case, a semi-glossy nickel plating layer on the lower layer, and a bright nickel plating layer on the upper layer on the outer surface of the battery case.

(04. Battery case with a matte nickel plating layer formed on the inner surface of the battery case and a semi-bright nickel plating layer formed on the outer surface of the battery case.

5. A battery case obtained by forming a surface-treated steel sheet having a semi-bright nickel plating layer formed on at least one surface of a plated steel sheet by a DI forming method or a DTR forming method.

\ ^ 6. A semi-bright nickel plating layer is formed on the inner side of the battery case, a semi-bright nickel plating layer is formed on the lower side, and a bright nickel layer is formed on the upper side. A surface-treated steel sheet for a battery case on which a plating layer is formed.

7. Surface-treated steel sheets for battery cases that have a semi-bright nickel plating layer on the inner and outer surfaces of the battery case.

10 8. A matte nickel plating layer is formed on the inner surface of the battery case, and a semi-bright nickel plating layer is formed on the lower layer on the outer surface of the battery case. Bright nickel plating is formed on the upper layer. A surface-treated steel sheet for a battery case on which a layer is formed.

9. A surface-treated steel sheet for battery cases in which a matte nickel plating layer is formed on the inner side of the battery case and a semi-glossy nickel plating layer is formed on the outer side of the battery case.

10. The semi-bright nickel plating layer forms an unsaturated carboxylic acid former as a brightener. The surface-treated steel sheet according to any one of claims 6 to 9, wherein the steel sheet is formed using a plating bath containing at least one of aldehyde, polyoxy-ethylene adduct, a nitrogen-containing complex compound, and a nitrogen-containing aliphatic compound. .