WO1997042668A1

WO1997042668A1 - Surface-treatment steel plate for battery case, its manufacture, battery case and battery

Info

Publication number: WO1997042668A1
Application number: PCT/JP1997/001577
Authority: WO
Inventors: Hitoshi Ohmura; Tatsuo Tomomori; Hideo Ohmura; Yukio Numamoto
Original assignee: Toyo Kohan Co., Ltd.
Priority date: 1996-05-09
Filing date: 1997-05-09
Publication date: 1997-11-13
Also published as: TW430698B; JP3539569B2; AU2652297A

Abstract

The object is to provide a surface-treatment steel plate for a battery case which has excellent forming properties and contributes to enhancing the battery performance and its manufacturing method and, further, to manufacture a battery case made of the surface-treatment steel plate efficiently at a low cost. A steel plate is subjected to degreasing, pickling and plating, or to degreasing, pickling, plating and heat treatment. The surface-treated steel plate is heated to a temperature about Tm to Tm+100 °C (Tm is the melting point of petroleum wax lubricant which is to be applied to the steel plate) and the melted lubricant is applied to the surface of the heated steel plate. The surface-treated steel plate is formed into a battery case by a deep-drawing process, a DI process for a DS process and then the formed battery case is subjected to a heat treatment at a low temperature of 200-350 °C.

Description

Specification

Surface treated steel sheet for battery case, method of manufacturing the same, battery case and battery

The present invention relates to a surface-treated steel sheet for a battery case, a method for manufacturing the same, a battery case using the surface-treated steel sheet, a method for manufacturing the same, and a battery using the battery case. More specifically, it is difficult to perform deep drawing, ironing (Drawing and Ironing, hereinafter abbreviated as DI), or stretching (Drawing and Strech forming, hereinafter abbreviated as DS). Surface-treated steel sheet formed by molding and suitable for a cylindrical battery case having an integrated bottom and body, a method for manufacturing the same, a battery case using the surface-treated steel sheet, a method for manufacturing the same, and the surface It relates to a battery using a treated steel sheet. Background art

In recent years, as a method of manufacturing a battery case that encloses strong alkaline liquid used in alkaline manganese batteries and nickel cadmium batteries, it has replaced the method of deep drawing a steel sheet into a battery case and then attaching it to a barrel. The mainstream method is to deep-draw a nickel-plated steel sheet or a surface-treated steel sheet subjected to heat treatment after nickel plating to form a battery case. In recent years, in particular, a method of manufacturing a battery case by DI processing has been used from the viewpoint of increasing the battery capacity, reducing the material cost by reducing the thickness of the battery case body wall, and improving the battery capacity. Was. Also, from the same viewpoint as described above, a method of manufacturing a battery case by DS processing is being studied. With the spread of manufacturing methods for these battery cases, materials for battery cases that not only have excellent battery performance but also have excellent moldability have been required. In general, in forming a battery case, a lubricant is applied to a battery case material such as a nickel-plated steel sheet before forming processing such as additional drawing, and after forming, the lubricant is removed by degreasing and washing. The method of drying is adopted.

In the above-described conventional method for manufacturing a battery case, a lubricant is uniformly applied to the battery case material immediately before press molding, or the lubricant is further lubricated in a pressing step. It is necessary to press work while lubricating oil is dropped, which requires extremely complicated work. In addition, after forming into a battery case, the two steps of degrease and cleaning the applied lubricant and drying after cleaning are indispensable. As described above, the conventional method of manufacturing a battery case is extremely insufficient in terms of labor saving, water resources, and heat energy consumption.

The present invention makes it possible to solve the above problems at the same time, and at the same time, provides a surface-treated steel sheet for a battery case excellent in battery performance and moldability, a method for producing the same, and a battery case using the surface-treated steel sheet It is an object of the present invention to provide a battery and a method of manufacturing the same, and a battery using the battery case. Disclosure of the invention

In the surface-treated steel sheet for a battery case of the present invention, the steel sheet is degreased and pickled, then plated, or coated with a petroleum wax-based lubricant on the surface-treated layer formed by further heat treatment after plating. It is characterized by having done. The surface treatment layer is one or more of nickel layer, nickel lurin alloy layer, nickel-iron alloy layer, nickel-tin alloy layer, nickel-phosphorus-tin alloy layer, nickel-tin-iron alloy layer The surface treatment layer preferably has a nickel content of 1 to 45 g / m ² . And the surface treatment layer is a multilayer composed of one or more of any one of a nickel-tin-tin alloy layer, a nickel-phosphorus-tin-tin alloy layer, and a nickel-tin-tin-iron alloy layer; The amount of tin contained is not more than 0.67 (weight ratio) of the amount of nickel plating. Furthermore, the petroleum wax-based lubricant is at least one of paraffin wax, microcrystalline phosphorus wax, liquid paraffin, petroleum overnight, white petroleum, polyethylene wax, polypropylene wax, and ethylene-propylene wax. Further, the application amount of the petroleum wax-based lubricant is 200 to 2000 mg / m ² . Further, the method for producing a surface-treated steel sheet for a battery case of the present invention is characterized in that the steel sheet is degreased and pickled, then plated, or subjected to a heat treatment after plating to form a surface-treated steel sheet. To the melting point (Τπ!) Of the petroleum wax lubricant to be applied to Tm + lOOt: Is applied. After degreasing and pickling the steel sheet, apply nickel plating or nickel-phosphorus alloy plating, or apply nigger plating or nigger-lin alloy plating, and then heat treat it in a non-oxidizing atmosphere. The steel sheet is degreased and pickled, then nickel-plated or plated with nickel-phosphorus, then tin-plated, and then in air or non-oxidizable. The heat treatment is performed in an atmosphere. Then, the oil-wax-based lubricant is applied to the surface-treated steel sheet in an amount of 200 to 2000 mg / m ² . Further, the method for manufacturing a battery case of the present invention includes a battery case formed by molding a surface-treated steel sheet for a battery case into a cylindrical container having a bottom portion and a body portion, and a surface-treated steel sheet for a battery case. After deep drawing, deep drawing, ironing or deep drawing, forming into a cylindrical battery case with a bottom and body integrated by stretching, then 200 to 350, 3 to 30 The invention is also directed to a battery characterized by performing a partial heat treatment, wherein a battery case is filled with a positive electrode mixture, a conductive agent and a negative electrode gel. BEST MODE FOR CARRYING OUT THE INVENTION

The present invention is characterized in that a steel plate is metal-plated or heat-treated in air or a non-oxidizing atmosphere after metal-plated, and a petroleum wax-based lubricant is applied on the formed surface treatment layer. I have. The applied petroleum wax-based lubricant significantly improves the formability such as deep drawing, and does not require removal by degreasing after forming.It is 200 to 35 (by heating at a temperature of TC. Most of the petroleum wax-based lubricant adhering to the obtained battery case can be volatilized and removed, and a surface-treated steel sheet for a battery case and a battery case excellent in formability that can reduce costs can be obtained.

Hereinafter, the present invention will be described in detail with reference to examples. First, the surface treatment layer formed on the steel sheet of the present invention will be described. Generally, surface-treated steel sheets for battery cases have excellent alkali corrosion resistance.When connecting the battery case to external terminals, they must have stable and low contact resistance. It is required to have excellent spot weldability when assembling parts by welding. As a result of various studies from these viewpoints, the surface treatment layer in the surface treated steel sheet for battery case Nickel plating layer, nickel-phosphorus alloy plating layer, nickel-iron alloy layer, nickel-tin alloy layer, nickel-iron-tin alloy layer, or a multi-layer composed of two or more of them That is, it has been found that the presence of a nickel plating layer and / or a surface treatment layer composed of an alloy layer mainly composed of nickel on a steel sheet sufficiently satisfies the above required characteristics.

For the formation of the surface treatment layer, a steel sheet may be degreased, pickled and then washed with water in a known manner, and the following method can be applied.

(1) Electric plating method

(2) Electroless plating method

(3) Heat treatment in non-oxidizing atmosphere after electroplating

(4) Heat treatment in non-oxidizing atmosphere after electroless plating

However, as a method for forming the surface treatment layer in the surface-treated steel sheet for a battery case of the present invention, the electroless plating is used rather than the methods (2) and (4) from the viewpoint of productivity. The methods (1) and (3) are preferred. The following method is used to form a surface treatment layer by electroplating. For example, in order to form a nickel plating layer, a known Watt bath, sulfamic acid bath, borofluoride bath or chloride bath may be used, and electrolysis may be performed using a steel sheet as a cathode. There is also a method of forming a nickel-iron alloy layer using a well-known nickel-iron alloy plating bath containing nickel ions and ferrous ions, but in this case, nickel and iron are convoluted. It is necessary to perform heat treatment in a non-oxidizing atmosphere to alloy nickel and iron.After nickel plating, heat-treat in a non-oxidizing atmosphere to alloy all the nickel However, it is preferable from the viewpoint of plating conditions, plating bath management and the like. In the case of forming a nickel-tin alloy layer, similarly to the case of forming a nickel-iron alloy layer, there is a method of using a known nickel-tin alloy plating bath containing nickel ions and divalent tin ions, Using a well-known nickel plating bath and tin bath, apply nickel plating, tin plating or tin plating, then nickel plating, and a resistance heating method in air and / or an induction heating method, which is known in the manufacture of tinplate. Heat treatment (reflow treatment), or heat treatment in a non-oxidizing atmosphere. After tin plating, nickel plating In this method, it is difficult to uniformly deposit nickel on the plated tin layer, which is not preferable. A more preferable method is a method of applying tin plating after nickel plating, and then performing a heat treatment. In the same manner as above, a nickel-tin-iron alloy layer is formed by using a plating bath containing all the ions, and then performing a heat treatment after the alloy is applied. As in the case of plating, it is preferable from the same point of view that tin plating is performed after nickel plating or nickel-iron alloy plating, and then heat treatment is performed in a non-oxidizing atmosphere.

When a steel sheet is nickel-plated and heat-treated in a non-oxidizing atmosphere, a nickel-iron alloy layer is formed between the nickel plating layer and the steel sheet. In some cases, only nickel or nickel and a nickel-iron alloy coexist in the outermost layer, and this can be selectively controlled by the amount of nickel plating and heat treatment conditions. Similarly, when the steel sheet is nickel-plated, tin-plated, and then heat-treated in a non-oxidizing atmosphere, the nickel-iron alloy layer, nickel-tin alloy layer, and tin-plated layer start from the side near the steel sheet. Layers may be formed or these surface treatment layers may coexist on the outermost layer, which can be easily selected and controlled by the nickel plating amount, tin plating amount, and heat treatment conditions. . From the viewpoint of battery performance, it is not preferable that the metallic tin remains on the inner surface of the battery case.The amount of tin applied to the inner surface of the battery case after the molding is determined by plating. It is necessary to limit the relationship with the amount of nickel plating and to set the amount so that all the metallic tin is alloyed by heat treatment. This will be described later. For forming the nickel-phosphorus alloy plating layer, a method using a known electroless plating bath can be applied. However, from the viewpoint of productivity, a known nickel-phosphorus alloy plating bath (for example, No. 2-1293335) is preferred.

Although the outermost surface of the surface treatment layer in the surface-treated steel sheet for a battery case of the present invention is preferably a nickel plating layer or an alloy layer mainly composed of nickel from the viewpoint of battery performance, the nickel plating amount is It is preferably from 5 to 45 g / m2, more preferably from 15 to 35 g / m2. If the nickel plating amount is less than 5 g / m2, the surface of the steel sheet cannot be coated sufficiently, and a surface-treated steel sheet with excellent battery performance can be obtained. I can't. On the other hand, if the nickel plating amount exceeds 45 g / m2, the battery performance saturates, which is not cost-effective.

Next, in forming the nickel-tin alloy layer, it is necessary to convert all tin plated on the inner surface of the battery case into a nickel-tin alloy by molding. If a part of the tin is left as metallic tin after alloying with nickel, the tin dissolves in potassium hydroxide, which is the electrolyte solution of alkaline batteries, and generates hydrogen, which significantly impairs battery performance, which is not desirable. . When heated at a temperature of 700 T or less in the heat treatment step, the formed alloy composition of nickel and tin is mainly composed of Ni3Sn, Ni3Sn2, and Ni3Sn4. Of these alloy compositions, a smaller amount of tin is required to form the alloy composition Ni 3Sn (the atomic weight ratio of Ni: Sn is 3: 1), which has the smallest ratio of tin to nickel. All tin will alloy with nickel. That is, the amount of tin plating should be at least 1/3 or less in atomic weight ratio with respect to the amount of nickel plating. Here, since the atomic weight of tin is 118.6 and the atomic weight of nickel is 58.7, the tin plating amount is set to about 0.67, as shown in the following formula, with respect to the nickel plating amount. Then, the atomic weight ratio of Ni: Sn becomes 3: 1. That is, the ratio of the amount of tin plating to the amount of nickel plating = 1 18.6 / (58.7 X 3) = about 0.67. If tin plating is performed at a ratio exceeding the above value (about 0.67), metallic tin may remain even after the heat treatment, which is not preferable in terms of battery performance as described above. Even if it does not remain as metallic tin, it becomes a nickel-tin alloy layer having a high tin content. An increase in the tin content ratio in the nickel-tin alloy layer is not preferable because battery performance may be reduced. Therefore, the weight ratio of tin plating to nickel plating is set to 0.67 or less.

A more preferred embodiment of the surface-treated steel sheet for a battery case of the present invention is a nickel-tin alloy layer, a nickel-tin alloy layer, or a steel sheet from the side where the surface treatment layer on the inner surface of the battery case after molding is in contact with the steel sheet. It consists of a nickel-iron-iron alloy layer and a nickel-tin-tin-iron alloy layer from the contact side. In any case, the outermost surface of the surface treatment layer is composed of a nickel-tin alloy layer or a nickel-tin-iron alloy layer It is more preferable that the plating is performed by a plating layer of nickel alone. This nickel-tin tin alloy layer or nickel-tin tin-iron alloy layer exhibits extremely excellent battery performance. For example, it significantly reduces the contact internal resistance of the battery. The reason can be clearly explained However, the nickel-tin-tin alloy layer or the nickel-tin-tin-iron alloy layer alloy layer forms numerous cracks with extremely irregularities on the surface due to the forming process, thereby increasing the contact area with the positive electrode mixture. This is considered to be because the contact resistance between the positive electrode mixture and the inner surface of the battery case was reduced. Alternatively, it is presumed that the physical properties of the alloy itself are affected (for example, the electric resistance is low). In the structure of the more preferable surface treatment layer described above, the nickel-iron alloy layer on the side in contact with the steel sheet and the metal-tin alloy layer formed on the nickel-tin alloy layer or the intermediate layer of the nickel-tin-iron alloy layer formed on the nickel-iron alloy layer are formed on the nickel-iron alloy layer. Although a nickel layer may be present, it does not particularly hinder battery performance, but rather has the effect of improving corrosion resistance, and is therefore preferable.

Next, a description will be given of a case of performing a heat treatment in a non-oxidizing atmosphere after metal plating, which is an embodiment of the method for producing a surface-treated steel sheet for a battery case of the present invention. It is preferable to perform this heat treatment in a non-oxidizing atmosphere in order to prevent oxidation of the outermost surface of the surface treatment layer. However, when tin plating is applied after nickel plating, and then both are alloyed by heat treatment, nickel and tin are alloyed at a temperature of 232, the melting temperature of tin in air, so that tinplate is produced. A generally-used resistance heating method and / or a short-time heating method using an induction heating method can be used. When a nickel-iron alloy layer is formed below the nickel-tin alloy layer to improve corrosion resistance, nigger hardly diffuses into the steel base at a heating temperature about the melting temperature of tin. It is necessary to perform heat treatment at a temperature of at least 450 in a non-oxidizing atmosphere. Specifically, heating at 450 to 850 requires 30 seconds to 15 hours. As a method of heat-treating a steel plate having been subjected to metal plating, a box-shaped annealing method and a continuous annealing method are known. In the present invention, any of these methods can be applied, and in the continuous annealing method, 600 to 850, 30 In the box-type annealing method, heat treatment is preferably performed for 450 seconds to 5 minutes, and for 5 to 15 hours. When forming a nickel-tin-iron alloy layer, it is necessary to perform a long-time heat treatment at a relatively high temperature to mutually diffuse the three element components. When heat treatment is performed in this way, temper rolling is required after heat treatment in order to prevent stretch strain caused by the heat treatment. Since this temper rolling is the final finish rolling, by changing the surface roughness of the work roll used in temper rolling, it is possible to obtain the desired surface roughness and surface appearance such as bright finish and dull finish. Can be.

Next, a petroleum wax-based lubricant applied on the above-mentioned surface-treated layer, which is a feature of the surface-treated steel sheet for a battery case of the present invention, and a method of applying the same will be described. The petroleum wax lubricant to be applied is selected from paraffin wax, microcrystalline wax, liquid paraffin, petrolatum, white petrolatum (vaseline), polyethylene wax, polypropylene wax, and ethylene-propylene wax. These lubricants have a melting point of 35 to 8 (T, generally solid or jelly-like at room temperature, and have fluidity when heated at low temperatures, making them easy to apply, depending on the oxidation state. In addition, after forming into a battery case, the coated petroleum wax lubricant is easily volatilized by heating in air at a temperature of 200 to 350 for 3 to 30 minutes. The melting point of White Petroleum Chromate (trade name: Sonojeluto 9, sold by Shima Trading Co., Ltd.) is about 42, and can be removed by short-time heating at low temperature. Yes, more preferred.

The amount of petroleum wax lubricant to be applied to the formed surface treated layer is preferably 200~2ϋΟΟ rag / m ^2, the range of 200~500nig / m ² is more preferable. If the application amount is 200 mg / m ² or less, for example, it is not possible to continuously perform deep drawing of 0000 or more cases at a rate of 50 cases / min. In some cases, the resulting battery case may have scratches on the side surface, and the mold may be worn a lot, which is not preferable. Further, when the coating amount exceeds 2000 mg / m ^2, similar but speed is possible to deep draw molding a more continuous manner 10000 cases, the adhering to the surface of the obtained batteries Case The amount of the lubricant is large, and it takes a long time to remove and volatilize by heating, which is not preferable. In addition, if most of the large amount of petroleum wax-based lubricant remains on the inner and outer surfaces of the battery case, the battery performance may be degraded, and paint or printing ink applied to the outer side wall of the battery case may be used. This is not preferable because it may lower the adhesion. Therefore, as long as the continuous productivity of the battery case is not hindered, it is preferable that the applied petroleum wax-based lubricant be as small as possible. This petroleum wax-based lubricant is melted by heating to a temperature between the melting point (Τπ!) And Tm + 100: and applied on the above-mentioned surface treatment layer. If the temperature is lower than the melting point, application is difficult, and if the temperature exceeds Tm + I OIT, the amount of volatilization increases, which is not preferable. The application method is to roll Any of a coating method, a spray coating method, and an electrostatic coating method can be applied.

As described above, using the surface-treated steel sheet for a battery case coated with a petroleum wax-based lubricant, the battery case of the present invention is formed by a known forming method such as deep drawing, DI forming, or DS forming. Manufactured. A petroleum wax-based lubricant applied to the used surface-treated steel sheet adheres to the inner and outer surfaces of the obtained battery case. However, some of the petroleum wax-based lubricant adhering to the obtained battery case adheres to the mold and the like at the time of molding, and therefore slightly decreases from the amount applied to the surface-treated steel sheet used. are doing. In any case, since the petroleum wax-based lubricant volatilizes at high temperatures, it can be easily removed by heating. The heating conditions of the battery case depend on the type of petroleum wax-based lubricant applied and the amount applied, but most of them are volatilized only by heating in air at a low temperature of 200 to 350 for 1 to 30 minutes. Can be done. If the heating temperature is 200 or less, even if the heating is performed for a long time, sufficient volatilization and removal cannot be performed, which impairs the productivity of the battery case. Although heating may be performed at a high temperature of 350 ^ or more, heat energy is lost, which is not economically preferable. For heating the obtained battery case, either an electric oven or a gas oven can be used.

Apply the above oil-based lubricant to the surface-treated steel sheet obtained as described above, and apply any of the following forming methods: deep drawing, ironing after deep drawing, or stretching after deep drawing. It is used to form a cylindrical so-called two-piece battery case with an integrated bottom and body. Which molding method is to be adopted is appropriately selected in consideration of processing difficulty, battery capacity, container strength, and the like. The molded battery case is heated at 200 to 350 for 3 to 30 minutes to remove the petroleum oil-based lubricant remaining on the battery case surface. At a heating temperature of less than 200, the oil wax-based lubricant cannot be completely volatilized and removed even if heated for more than 30 minutes. The higher the heating temperature, the more volatile the petroleum wax lubricant becomes, and the shorter the heating time becomes. However, it is necessary to heat the lubricant for at least 3 minutes in order to completely remove it. On the other hand, when heated at a temperature exceeding 350, the steel sheet softens and the strength of the battery case decreases. For the above reasons, the heating condition of the molded battery case is limited to 200 to 35 (3 to 30 minutes in the temperature range of T. The positive electrode mixture, conductive agent and The battery is filled with the negative electrode gel.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

(Example) A cold-rolled and annealed low-carbon aluminum-killed steel sheet having a thickness of 0.25 mm was used as an original sheet for metal plating. The chemical composition of the steel of this master plate is as follows.

C: 0.03% (% is weight%, the same applies hereinafter), Mn: 0.18%, Si: 0.01%, P: 0.013%, S: 0.012%, A1: 0.054%, N: 0.0038% The above steel sheet is caustic soda concentration: 30 g / l, bath temperature: 80: cathode current density: 10A / dni ^2, electrolysis time: subjecting the alkaline cathodic electrolytic degreasing under the condition of 20 seconds, washed with water, sulfuric acid concentration: 50 g / L bath temperature: 30, immersion time : Pickling was performed for 5 seconds, and after washing with water, metal plating was performed under various conditions shown below.

(1) Nickel plating conditions

Bath composition: Nickel sulfate 320 g / 1

Nickel chloride 40 g / 1

Boric acid 30 g / 1

Commercial semi-brightener (unsaturated alcohol polyoxyethylene,

1.0 g / 1 containing unsaturated carboxylic acid

Sodium laurate 0.5 g / 1

H: 4. 4.6

Bath temperature: 55 ± 2

Current density: 15A / dm ²

Anode: Nickel pellets (Titanium baskets are filled with nickel pellets, and the titanium basket is covered with a polypropylene bag.)

(2) Tin plating conditions

Bath composition: stannous sulfate 30 g / 1

Phenolsulfonic acid (65% solution) 60 g / 1

Ethoxylated α-naphle] 5 g / 1

Bath temperature: 50 ± 2 "C

Current density: 20 A / dm ²

Anode: Tin plate 1

(3) Nickel-phosphorus alloy plating conditions

Bath composition: Nickel sulfate 150 g / 1

Nickel chloride 80 g / 1

Phosphorous acid 30 g / 1

pH: 0.6

Bath temperature: 50 X:

Current density: 3 A / dm ²

Anode: Same as the anode used for nickel plating

(Examples 1 to 3) Nickel plating was performed under the conditions described in (1) above. The amount of nickel plating was adjusted by changing the electrolysis time. After nickel plating, a petroleum-based lubricant shown in Table 1 was applied.

(Examples 4 to 6) The nickel-plated steel sheets obtained in Examples 1 to 3 were prepared in a non-oxidizing atmosphere containing 6.5% of hydrogen and the balance of nitrogen and having a dew point of 40T :, and a soaking temperature of 550: Heat treatment was performed under the condition that the soaking time was 6 hours, and then temper rolling was performed at an elongation of 1.0%. A petroleum wax-based lubricant shown in Table 1 was applied to the obtained surface-treated steel sheet. (Example 7) After nickel plating at 20. Og / m ^{2 under} the conditions shown in (1) above, tin plating at 0.9 g / m ^{2 under} the conditions shown in (2) above, and in air The surface layer was formed into a nickel-tin alloy by the resistance heating method, and the petroleum wax-based lubricant shown in Table 1 was applied. (Examples 8 to 10) A surface-treated steel sheet which was nickel-plated under the conditions shown in (1) above and then tin-plated under the conditions shown in (2) above was replaced with 6.5% hydrogen and the remainder nitrogen. In a non-oxidizing atmosphere having a dew point of 140, heat treatment was performed under the conditions of a soaking temperature of 700 and a soaking time of 3 minutes, followed by temper rolling at an elongation of 1.2%. The petroleum wax-based lubricant shown in Table 1 was applied to the obtained surface-treated steel sheet. The amount of nickel plating and the amount of tin plating were adjusted by changing the electrolysis time.

(Example 11) After plating nickel at 18. Og / m ^{2 under} the conditions shown in (1) above, plating a nickel-phosphorus alloy at 5.8 g / m ^{2 under} the conditions shown in (3) above Content: 12). A petroleum wax-based lubricant shown in Table 1 was applied to the obtained surface-treated steel sheet.

(Examples 12 to 14) After nickel plating under the conditions shown in (1) above, A surface-treated steel sheet coated with a nickel-phosphorous alloy (phosphorus content .10 to 12%) under the conditions shown in (3) was converted to a non-deposited steel sheet with 5.5% hydrogen, the balance being nitrogen, and a dew point of 135 一. Heat treatment was performed in an oxidizing atmosphere at a soaking temperature of 650 at a soaking time of 4 hours, followed by temper rolling at an elongation of 1.5%. The resulting surface-treated steel sheet was coated with a petroleum oil-based lubricant shown in Table 1. The amount of nickel plating and the amount of nickel-phosphorus alloy were adjusted by changing the electrolysis time.

(Comparative Example 1)

A petroleum wax-based lubricant shown in Table 1 was applied to a nickel-plated steel plate that had been plated with 4. Og / m ² nickel under the conditions shown in (1) above.

(Comparative Example 2)

A nickel-plated steel sheet plated with 20.5 g / m ² of nickel under the conditions shown in (1) above was heat-treated and temper-rolled under the same conditions as in Examples 4 to 6, and then the petroleum wax-based lubrication shown in Table 1. The agent was applied.

(Comparative Example 3)

After nickel plating of 8. Og / m ^{2 under} the conditions shown in (1) above, tin plating of 5.6 g / m ² was performed, and heat treatment was performed in air by a resistance heating method. A petroleum wax-based lubricant shown in Table 1 was applied to the obtained surface-treated steel sheet.

(Comparative Example 4)

The surface-treated steel sheet, which had been subjected to nickel plating of 35. Og / m ^{2 under} the conditions shown in (1) above and then subjected to tin plating at 1.2 g / m ^{2 under} the conditions shown in (2) above, Heat treatment and temper rolling were performed under the same conditions as in 8 to 10, and a petroleum wax-based lubricant shown in Table 1 was applied.

(Comparative Example 5)

35. Og / m ² nickel plating under the conditions shown in (1) above, followed by nickel-phosphorus alloy plating (nickel: 5.5 _g / m2) under the conditions shown in (3) above The petroleum wax-based lubricant shown in Table 1 was applied to each of them.

(Comparative Example 6)

The same surface-treated steel sheet as in Comparative Example 5 was subjected to heat treatment and temper rolling under the same conditions as in Examples 12 to 14, and then a petroleum wax-based lubricant shown in Table 1 was applied. The continuous formability and battery performance of the battery case of the surface-treated steel sheets obtained in Examples 1 to 14 and Comparative Examples 1 to 6 were evaluated using the following methods. The evaluation results are shown in Tables 3 and 4 together with the heating conditions after molding.

(1) Evaluation of battery case continuous formability

The surface-treated steel sheets for battery cases obtained in Examples 1 to 14 and Comparative Examples 1 to 6 were punched into blanks, and then subjected to eight steps of drawing forming (drawing speed of 50 cases / min) to obtain a case height of 49.3. After continuously forming a cylindrical case with a case outer diameter of 13.8, the upper open end was trimmed to obtain a battery case.

The quality of the continuous formability was evaluated according to the following criteria.

◎: Continuous molding of 10,000 cases or more, no scratches on the side of the case,

〇: 5000 to 10,000 cases can be continuously formed without scratches on the side of the case, but scratches occur on the side of the case after 10,000 cases or more

Δ: Continuous molding of 2000 to 5000 cases can be performed continuously without scratches on the side of the case, but scratches occur on the side of the case at 5000 cases or more. X: Less than 2000 cases of continuous molding, scratches on the side of the case. Frequently

(2) Evaluation of battery performance

After the battery case obtained by the method shown in the above 1 was subjected to a heat treatment under the conditions shown in Tables 3 and 4, an alkaline manganese battery was manufactured by the following method.

First, manganese dioxide and graphite were collected at a weight ratio of 10: 1, and potassium hydroxide (8 mol) was added and mixed to prepare a positive electrode agent. Then, this positive electrode material was pressed in a mold to produce a donut-shaped positive electrode material pellet having a predetermined size, and inserted into the obtained battery case and pressed.

Next, in order to mount the negative electrode plate spot-welded with the negative electrode current collector rod to the battery case, a predetermined position below the opening end of the battery case was neck-in processed. Next, a separator made of nonwoven fabric made of vinylon is introduced along the inner periphery of the pellet pressed into the battery case, and a negative electrode gel made of potassium hydroxide saturated with zinc particles and zinc oxide is placed in the battery case. Was inserted.

Furthermore, an insulator gasket was attached to the negative electrode plate, inserted into a battery case, and then caulked to produce an alkaline manganese battery. After leaving this alkaline manganese battery at room temperature for 24 hours, the battery performance was measured. The battery performance was evaluated by two items: the internal resistance value (ιηΩ) based on the AC impedance (frequency 1 kHz), and the short-circuit current value (Α) under an lmΩ load. The internal resistance value and the short-circuit current value were both measured at 20. The evaluation results of the continuous formability and battery performance of the obtained battery case are shown in Tables 3 and 4 together with the battery case heating conditions.

In Tables 1 and 2, the types of petroleum wax-based lubricant applied to the surface-treated steel sheet are indicated by the following symbols.

A: Paraffin wax

B: Micro Chris Yu phosphorus wax

C: Liquid paraffin

D: Petrolatum

E: White petrolatum (vaseline)

In Tables 3 and 4, the overall evaluation is that the battery case has excellent continuous formability, low internal resistance, and large short-circuit current. ◎ The battery case has excellent continuous formability. The battery performance was not a problem in practical use, but was slightly inferior, and the battery case continuous formability and battery performance were markedly inferior were indicated by X.

Summarizing the evaluation results in Tables 3 and 4,

(1) Among the surface-treated steel sheets for a battery case of the present invention, the outermost layer is a nickel-tin tin-based surface-treated steel sheet (Examples? To 10) is a nickel-based (Examples 1 to 6) and a nickel-lurin alloy. Battery performance is superior to that of the system (Examples 11 to 14).

(2) The battery performance of the nickel-plated steel sheet shown in Comparative Example 1 was inferior to that of the Nigel surface-treated steel sheets shown in Examples 1 to 6 because the nickel plating amount was small. The continuous formability of the battery case made of nickel-based surface-treated steel sheet is poor because the applied petroleum wax-based lubricant is small.

(3) The battery performance of the nickel-tin-tin alloy surface-treated steel sheet of Comparative Example 3 was inferior because the applied petroleum wax-based lubricant was large and a large amount of the lubricant remained in the obtained battery case. , And metal tin remains in the outermost layer. In addition, the inferior battery performance of the nickel-tin alloy surface-treated steel sheet shown in Comparative Example 4 was due to the lubrication applied. Although the amount of the lubricant was small, the heating temperature of the obtained battery case was low, and the lubricant remained.

(4) In the nickel-phosphorus alloy-based surface-treated steel sheet shown in Comparative Example 5, the amount of the applied lubricant was small, and the battery case continuous formability was poor. In addition, the heating time of the obtained battery case is short, the lubricant remains, and the battery performance is poor.

(5) The nickel-phosphorus alloy surface-treated steel sheet shown in Comparative Example 6 is excellent in battery case continuous formability and the battery performance is the same as the nickel-phosphorus surface-treated steel sheets of Examples 11 to 14. This is an example in which the obtained battery case is heated for a long time, which is not preferable from the viewpoint of productivity and cost reduction of the battery case.

From these Examples and Comparative Examples, the surface-treated steel sheet for a battery case described in the claims of the present invention was excellent in continuous formability of the battery case, and further, a battery case using the surface-treated steel sheet was identified. It can be seen that the battery produced after the heat treatment under the conditions had excellent battery performance.

Table 1 State of the obtained surface-treated steel sheet Metsu Surface treatment layer Lubricant applied Type and amount of plating

(g / m ² ) Heat treatment State Type Quantity (mg / m ² )

1 Ni: 5.5 Ni A 250

2 Ni: 21.5 ", Ni A 550

3 Ni: 40.8 No Ni B 1500 plan

4 Ni: 5.2 with Ni-Fe D 300

5 Ni: 15.7 Yes Ni, Ni-Fe E 830

6 Ni: 39.8 Yes Ni C 1700

7 Ni: 20.0 → Sn: 0.9 Yes Ni-Sn E 1350 Example 8 Ni: 8.0 → Sn: l.1 Yes Ni-Sn-Fe C 800

9 Ni: 18.5 → Sn: 5.6 Existence Ni, Ni-Sn E 350

10 Ni: 40.2 → Sn: 10.56 Exist Ni-Sn D 210 Table 2 State of the obtained surface-treated steel sheet

Plating Surface treatment layer Lubricant applied Type and amount of plating

(g / m ² ) Heat treatment State Type Quantity (mg / m ² ) ΐ

11 Ni: 8.0 → Ni-P (Ni: l.5) Ni, Ni-P D 220

12 Ni: 6.0 → Ni-P (Ni: 3.0) Exist Ni-P E 350

13 Ni: 15 → Ni-P (Ni: 0.5) Yes Ni-P, Ni-Fe E 550 Example

14 Ni: 38 → Ni-P (Ni: 5.0) Exist Ni-P C 1900

1 Ni: 1.0 Ni B 550

Ratio 2 Ni: 20.5 Yes Ni, Ni-Fe A 100

3 Ni: 8.0 → Sn: 5.6 Exist Sn, Ni-Sn E 2500 comparison

4 Exist Ni-Sn D 150

Example 5 Ni: 35 → Ni-P (Ni: 5.5) Ni-P C 100

6 Ni: 35 → Ni-P (Ni: 5.5) Exist Ni-P E 500 Table 3 Heating conditions after battery case molding and characteristic evaluation results Heating conditions after molding Battery case Battery performance Total continuous evaluation Temperature CC) Time (min) Moldability Internal resistance Short-circuit current Value

1 250 5 〇 175 6.0 〇 Actual 2 300 10 ◎ 180 5.8 〇

3 350 20 ◎ 178 5.5 〇

4 210 5 〇 175 5.8 〇

5 250 10 ◎ 165 5.8 施 Facility

6 300 30 ◎ 168 6.0 〇

7 200 20 ◎ 130 8.5 ◎

8 300 3 ◎ 129 9.0 ◎ Example 9 250 15 ◎ 125 9.4 ◎

10 250 5 〇 118 9. 6 ◎ Table 4 Heating conditions after battery case molding and characteristic evaluation results Heating conditions after molding Battery case Battery 1 ±

Temperature C) Time (min) Formability Internal resistance Short-circuit current

11 200 5 〇 175 4.5 〇

12 200 15 ◎ 165 5.5 〇 Facility

13 250 5 ◎ 170 5.0 例 Example

14 350 10 ◎ 168 6.0 〇

1 300 5 ◎ 270 3.2 X Ratio 2 150 5 X 175 3.5 X

3 250 10 ◎ 268 5.5 Compare X

4 100 5 Δ 250 5.0 X Example 5 250 2 X 180 6.5 X

6 150 40 ◎ 185 5.7 X Industrial applicability

The surface-treated steel sheet for a battery case of the present invention is more efficiently formed than a conventional surface-treated steel sheet for a battery case, in which a lubricant is applied to a blank or a mold each time immediately before forming into a battery case. Can be processed. In addition, after forming into the battery case, it is not necessary to degrease, wash and dry the applied lubricant as in the past, and most of the lubrication can be easily achieved by heat treatment at a low temperature of 200 to 350: It is possible to provide a production method capable of removing the agent and efficiently producing a battery with excellent battery performance and reducing costs, and its industrial value is extremely large.

Claims

The scope of the claims

1. A surface-treated steel sheet for a battery case in which a petroleum wax-based lubricant is applied on the surface-treated layer formed on the steel sheet.

2. The surface treatment layer is selected from the group consisting of a nickel layer, a nickel-phosphorus alloy layer, a nickel-iron alloy layer, a nickel-tin alloy layer, a nickel-phosphorous-tin alloy layer, and a nickel-tin-iron alloy layer. The surface-treated steel sheet for a battery case according to claim 1, wherein the steel sheet is any one of the layers.

3. The surface treatment layer is selected from a nickel layer, a nickel-phosphorus alloy layer, a nickel-iron alloy layer, a nickel-tin alloy layer, a nickel-phosphorous-tin alloy layer, and a nickel-tin-iron alloy layer. 2. The surface-treated steel sheet for a battery case according to claim 1, wherein the steel sheet has a multilayer structure composed of the above.

4. The surface-treated steel sheet for a battery case according to claim ² , wherein the amount of nickel contained in the surface-treated layer is 1 to 45 g / m2.

5. The surface treatment layer is any one of a nickel-tin alloy layer, a nickel-phosphorus-tin alloy layer, and a nickel-tin-iron alloy layer, and tin contained in the surface treatment layer 2. The surface-treated steel sheet for a battery case according to claim 1, wherein the amount is 0.67 or less by weight relative to the amount of nickel plating.

6. The petroleum wax-based lubricant is at least one of paraffin wax, microcrystalline phosphorus wax, liquid paraffin, petrolatum, white petrolatum, polyethylene wax, polypropylene wax, and ethylene-propylene wax. Surface treatment steel for battery case according to any of 5 above.

7. The surface-treated steel sheet for a battery case according to claim 6, wherein the applied amount of the petroleum wax-based lubricant is 200 to 2000 mg / in ² .

8. Degreasing and pickling of steel sheet, plating or heat treatment after plating to form a surface treatment layer, and then the melting point (Tn!) ~ Tm + l of the petroleum wax-based lubricant to be applied to the steel sheet OOt: A method for producing a surface-treated steel sheet for a battery case, which comprises heating a petroleum wax-based lubricant to a surface thereof and applying a petroleum wax-based lubricant to the surface.

9. The method for producing a surface-treated steel sheet for a battery case according to claim 8, wherein the surface-treated layer is a nickel-plated layer or a nickel-phosphorus alloy-plated layer, or is a two-layer structure comprising both layers.

10. Degreasing and pickling the steel sheet, plating it with nickel plating or nickel-phosphorus alloy, then plating it with tin, and then heat-treating it in the air or in a non-oxidizing atmosphere. After forming the layer, heat to the melting point (Τπ!) ~ Tm + lOOt: of the petroleum oil-based lubricant to which the steel sheet is to be applied, and apply the heat-melted oil-water-based lubricant to the surface. A method for producing a surface-treated steel sheet for a battery case, comprising:

1 1. The petroleum wax-based lubricant according to claim 6, 200~2000 mg / m ² a method for producing a surface-treated steel sheet for battery case according to claim 8, characterized in that the coating.

12. A battery case formed by molding the surface-treated steel sheet according to any one of claims 1 to 7 into a cylindrical container having a bottom portion and a body portion integrated with each other.

13. The bottom and torso of the surface-treated steel sheet according to any one of claims 1 to 7 by deep drawing, ironing after deep drawing, or stretching after deep drawing. A method for manufacturing a battery case, comprising: forming a cylindrical battery case in which is integrated; and subjecting the case to heat treatment at 200 to 350 for 3 to 30 minutes.

14. A battery using the battery case according to claim 12.