JP5241063B2 - Square can lid - Google Patents

Description

  The present invention is a resin-coated can lid for a rectangular can formed by using an aluminum plate coated with an unstretched polyester film, and for a rectangular battery case or a rectangular electric device case filled with a power generation element or the like. The present invention relates to a rectangular can lid that is applied to a rectangular can that is highly resistant to leaking and is suitable for the above.

  Generally, as a component structure of a metal container (can), a can body is formed by three members in which a can body is formed by welding, bonding, soldering, caulking, etc., and a canopy and a bottom cover are attached to both end openings. There are three-piece cans with joints.

  On the other hand, there is known a two-piece can composed of two members in which a canopy is attached to an opening of a round or square bottomed can obtained by deep drawing or drawing / squeaking a flat blank. In general, laser welding, caulking, double winding, or the like is applied as a sealing method for attaching a lid to the opening of both the three-piece and two-piece cans.

In recent years, advances in electrical technology have led to advances in the performance, size, energy, and portability of electronic devices, as well as improvements in the performance of electrically driven vehicles (including so-called hybrid vehicles). In addition, various batteries that are power sources for driving them, particularly containers for electric double layer capacitors, are required to have excellent liquid leakage resistance, can strength, air tightness, heat dissipation, and the like.
The contents leakage resistance and airtightness in the battery and the electrical equipment container mean that the contents are not leaked over a long period of time after filling the power generation element, and the sealing performance is maintained. It is often influenced by the joining state in can body formation and the sealing state of the container body and the lid.

  In Japanese Patent Application Laid-Open No. 2002-343310 (Patent Document 1), it is assumed that a two-piece can is applied to a case for an electric device and a sealing by double winding is adopted. It has been proposed that an insulator is sandwiched between the two and double-tightened.

Also, in Japanese Patent No. 3427216 (Patent Document 2), “sealing by double winding and pressing method was examined. However, these methods had a problem that an air-sealing port was difficult” (Patent Document 2, As a solution to the problem from the bottom of the right column of the first page to the second line from the top of the left column of the second page, it functions as a gasket when sealing by sealing a metal film with a resin film such as a polypropylene film in advance. There is an example that proposed to make it.
Furthermore, when a plurality of batteries are accommodated as a unit, the rectangular shape of the battery case can be made square from the viewpoint of increasing the volume efficiency because the rectangular battery case can be arranged without gaps rather than the cylindrical shape. Has been done.
JP 2002-343310 A Japanese Patent No. 3427216

The proposed double-wrapping and sealing can has improved leakage resistance and meets the requirements of battery cases and electrical equipment cases. Recently, however, the radius of the corners of square cans has been reduced. When the cans are juxtaposed, the space between the cans is reduced to increase the volumetric efficiency, and the can lid applied to such a rectangular can also has a shape corresponding to the radius of the four corners of the rectangular can. There is a need for a square can lid having a small radius shape.
However, when forming a square can lid with such a small radius, film wrinkles occur at the chuck wall portions at the corners of the square can lid, and this wrinkle impairs the sealing performance of the double winding portion. There is. Furthermore, film wrinkles also have a problem of inhibiting the corrosion resistance of the rectangular can lid.
An object of this invention is to provide the square can lid which improved the sealing property of the double winding part of a square can regardless of a 3 piece can and a 2 piece can.

The rectangular can lid according to claim 1 of the present invention is
A lid attached to the flange provided in the opening that forms the square can by double tightening via an organic compound,
The lid is made of an aluminum plate having at least an inner surface coated with an unstretched polyester film whose crystallinity is in the range of 20 to 40% by preheating before molding,
The radius (R) of the chuck wall corners at the four corners of the lid that is double-wrapped and attached to the opening of the rectangular cylinder is in the range of 5 to 10 mm .

The rectangular can lid according to claim 2 is characterized in that in claim 1,
The rectangular can is a battery case, and a through hole is provided in a central portion of the lid, and an electrode is attached to the through hole via an insulator.

The unstretched polyester-coated aluminum plate applied to the present invention is preheated before being formed into a can lid, and the crystallinity of the coated film is within the range of 20 to 40%. Part film peeling), and the liquid leakage resistance by the double tightening part is extremely high.
In addition, the rectangular can lid of the present invention can complete the sealing in the double winding portion without causing film wrinkles in the corner portion even when the radius R of the four corner portions is as small as 10 mm or less. it can.
Furthermore, since the rectangular can lid of the present invention has high leakage resistance at the double tightening portion, a can for a battery case can be obtained by providing a through hole in the center of the rectangular can lid and attaching an electrode via an insulator. It is also excellent as a lid.

Hereinafter, the structure of the square can lid which consists of an unstretched polyester covering aluminum plate of this invention and the square can which double-tightened it is demonstrated in detail.
FIG. 1 is a perspective view showing a state before a square can lid of the present invention is attached to a square can body. In FIG. 1, a rectangular can lid 1 has a center panel 1a located in a central recess that constitutes most of the can lid, and an outer edge portion 1b located on the outer periphery thereof. Further, the outer edge portion 1b includes a chuck wall portion 1w that rises vertically from the inner center panel 1a, and a seaming panel 1p that extends in the horizontal direction from a peripheral end portion of the chuck wall portion 1w.
A cover hook 1h that hangs downward on the peripheral edge of the seaming panel 1p.

When the can lid is attached to the rectangular can body, the outer wall of the chuck wall portion 1w of the rectangular can lid 1 is inscribed in the can body opening 2k of the rectangular can body 2, while the sheet of the rectangular can lid 1 is in contact. The rimming panel 1p and the flange 2f formed by extending the peripheral edge of the can body opening portion in the horizontal direction are overlapped and wound between the outer edge portion 1b of the rectangular can lid 1 and the flange 2f of the can body 2 The opening of the can body 2 is sealed while forming the portion.
In FIG. 1, the square can body 2 is shown as a two-piece can type formed into a square tube with a bottom by square deep drawing, but the square can body may be a square tube without a bottom. In this case, it becomes a 3 piece can type in which the same lid as the can lid 1 is attached to both ends of the rectangular can body as a canopy and a bottom lid.

  Hereinafter, the material aluminum plate forming the rectangular can lid of the present invention, the surface treatment of the aluminum plate, and the resin film will be described. Further, the method of coating the resin film on the aluminum plate, the preheating treatment of the resin-coated aluminum plate, the can body The manufacturing process will be described in detail.

FIG. 2 is a cross-sectional view for explaining a material forming the rectangular can lid of the present invention.
The rectangular can lid of the present invention is formed of an aluminum plate obtained by laminating a polyester film 12 having a specific crystallinity on at least one surface of an aluminum plate as a material in order to increase corrosion resistance. As shown in FIG. 2 (a), the resin-coated aluminum plate is provided with a surface treatment layer 11 described later on the surface of the aluminum plate 10 as a base material in order to improve adhesion when a polyester film is laminated. It is desirable that a resin film 12 described later is laminated on the surface treatment layer 11 as shown in FIG.

Hereinafter, the aluminum plate 10, the surface treatment layer 11, the resin film 12, and the film laminating method serving as a base material will be described in detail.
(Aluminum plate)
Examples of the aluminum plate 10 that serves as a base material for the rectangular can lid of the present invention include various aluminum materials, for example, alloys in the 3000s, 5000s, and 6000s described in JIS4000. Among them, those in the 3000s are preferable. Used.

Hereinafter, the composition of the aluminum plate will be described.
Since Mn increases the recrystallization temperature of aluminum and changes the crystallization state as a compound to improve the strength and corrosion resistance of the rectangular can lid, 1.0 to 1.5% (% is based on weight (wt)) The same applies hereinafter). If the amount of Mn added is less than 1.0%, the strength and corrosion resistance of the rectangular can lid cannot be sufficiently obtained. On the other hand, if the amount of Mn added exceeds 1.5%, the above effects are saturated, and Al -Mn-based and Al-Mn-Fe-based crystallized products are coarsened, and the double-clamping processability is lowered.

  Cu is preferably added in an amount of 0.05 to 0.20% because it is effective in improving the strength of the rectangular can lid and making the crystal fine. If the added amount of Cu is less than 0.05%, the strength of the rectangular can lid cannot be sufficiently obtained. On the other hand, if the added amount of Cu exceeds 0.20%, a coarse crystallized product is formed, Winding processability is reduced.

  Mg is preferably added in the range of 0.8 to 5.0% because it improves the strength, formability, corrosion resistance and the like of the rectangular can lid. When the added amount of Mg is less than 0.8%, the strength of the rectangular can lid cannot be sufficiently obtained, while when the added amount of Mg exceeds 5.0%, the double winding processability is deteriorated, Cracks and wrinkles are likely to occur.

  As other components, the following elements are particularly defined in the present invention. Si has an effect of improving the strength, wear resistance, etc. of the rectangular can lid by precipitating an intermediate phase with Mg, but it is preferably 0.6% or less. When the addition amount of Si exceeds 0.6%, the double-clamping formability is lowered, and cracks, wrinkles and the like are likely to occur. However, Si is contained in bullion and can scraps, and a large amount of cost is required to reduce this, and a certain amount must be allowed.

Fe has an effect of improving the corrosion resistance of the can lid by changing the crystallization state using Mn in aluminum as a compound, but it is preferably 0.7% or less. If the added amount of Fe exceeds 0.7%, the double-clamping formability decreases, and cracks, wrinkles, etc. are likely to occur. However, Fe, like Si, is contained in metal and can scrap, and it requires a great deal of cost to reduce this, and a certain amount must be allowed.
Since Zn is effective in improving the strength of the can lid and refining the crystallized substance, it is preferable to add a certain amount. However, if the added amount of Zn exceeds 0.10%, a coarse crystallized product is generated, and the workability is lowered.

  The thickness of the aluminum plate as the can lid after molding is preferably in the range of 0.1 to 1.0 mm from the viewpoint of can lid strength and moldability, but the plate thickness of the center panel 1a after molding. The minimum aluminum plate thickness excluding the coating resin is preferably 0.3 mm or more. This is because the pressure resistance of the can lid is insufficient when the minimum aluminum plate thickness of the center panel 1a is 0.3 mm or less.

(Surface treatment layer)
The aluminum plate is preferably subjected to a surface treatment on the surface in order to improve processing adhesion to the coating resin. As such surface treatment, an aluminum plate can be cold-rolled, and chromium phosphate treatment or other organic / inorganic surface treatment can be performed by dipping or spraying. A coating type surface treatment can also be used. When a treatment film is formed on the aluminum plate by chromic acid phosphate treatment, from the viewpoint of processing adhesion of the resin film to be laminated, the chromium content is preferably 5 to 40 mg / m ² as total chromium, and 15 to 30 mg / m. A range of ² is more preferred.

When surface treatment such as chromium phosphate treatment is not performed, adhesion after processing of the resin film is lowered, and peeling may occur after molding and washing. Even when the amount of the total chromium containing the metal and the oxide is less than 5 mg / m ² , the processing adhesion of the resin film is lowered, and peeling may occur, which is not preferable. Moreover, when the amount of total chromium exceeds 40 mg / m < ² >, it is unpreferable from an economical viewpoint, the viewpoint of the adhesive fall by cohesive failure generation, etc. On the other hand, when the chromic acid phosphate treatment is performed on the side where the resin film is not laminated, the total chromium amount is 8 mg / m ² or less. If the total amount of chromium on the outer surface exceeds 8 mg / m ² , color unevenness occurs or the metallic luster color tone is lost. This is because the metallic luster is important as the appearance color of the can.

As an example of the formation method of the surface treatment layer 11, the formation of the chromic acid chromic acid treatment film is performed by means known per se, for example, an aluminum plate is degreased with caustic soda and slightly etched, and then CrO ₃ : 4 g / L, H ₃ PO ₄ : 12 g / L, F: 0.65 g / L, and the rest is performed by chemical treatment immersed in a treatment solution such as water.

(Laminated resin film)
On at least one side of the rectangular can lid of the present invention, a resin film 12 is formed on a surface-treated aluminum plate. Examples of the resin film 12 include an unstretched polyester film. As the unstretched polyester film, a film mainly composed of ethylene terephthalate, ethylene butyrate, or ethylene isophthalate is preferably used. This resin film is formed into a film by a T-die method or an inflation film forming method.
The polyester film can be copolymerized with other components. For example, dicarboxylic acid components to be copolymerized include naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenoxyethanedicarboxylic acid, 5-sodium sulfoisophthalic acid, phthalic acid and other aromatic dicarboxylic acids, oxalic acid, succinic acid Examples thereof include aliphatic dicarboxylic acids such as acid, adipic acid, sebacic acid, dimer acid, maleic acid and fumaric acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and oxycarboxylic acids such as p-oxybenzoic acid.

  Examples of the glycol component to be copolymerized include aliphatic glycols such as propanediol, butanediol, pentanediol and neopentylglycol, alicyclic glycols such as cyclohexanedimethanol, aromatic glycols such as bisphenol A and bisphenol S, and diethylene glycol. And polyoxyethylene glycols such as polyethylene glycol. About said dicarboxylic acid component and glycol component, 2 or more types can also be used together.

(Polyethylene terephthalate film)
The polyethylene terephthalate film suitably used as the polyester film is composed of 70 mol% or more, particularly 75 mol% or more of the dibasic acid component in the copolyester, and more preferably 70 mol% or more of the diol component. 75 mol% or more is composed of ethylene glycol, and 1 to 30 mol%, particularly 5 to 25 mol% of the dibasic acid component and / or diol component is a dibasic acid component other than terephthalic acid and / or a diol component other than ethylene glycol. Preferably it consists of.
Examples of dibasic acids other than terephthalic acid include aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid: alicyclic dicarboxylic acids such as siloxane hexanedicarboxylic acid; succinic acid, adipic acid, sebacic acid, dodecanedioic acid Aliphatic dicarboxylic acids such as: one or a combination of two or more thereof, and diol components other than ethylene glycol include propylene glycol, 1,4-butanediol, diethylene glycol, 1,6-hexylene glycol, cyclohexane 1 type, or 2 or more types, such as dimethanol and the ethylene oxide adduct of bisphenol A, are mentioned.
The combination of these comonomers must be such that the melting point of the copolyester is within the above range.
The copolyester used should have a molecular weight sufficient to form a film, for which purpose an intrinsic viscosity (IV) of 0.55 to 1.9 dl / g, in particular 0.65 to 1.4 dl / g. Those in the range of g are desirable.
It is important that the copolyester film is biaxially stretched. The degree of biaxial stretching can also be confirmed by polarized fluorescence method, birefringence method, density gradient tube method density and the like.

(Film thickness)
The polyester film preferably has a thickness of 2 to 50 μm, particularly 12 to 40 μm, in view of the balance of barrier properties, workability, and openability of the corrosive component.
For this biaxially stretched polyester film, a film compounding agent known per se, for example, an anti-blocking agent such as amorphous silica, a pigment such as carbon black (black), various antistatic agents, a lubricant, etc., according to a known formulation. Can be blended.

(Adhesion primer)
An adhesive primer can be interposed between the polyester film and the aluminum plate, but those exhibiting excellent adhesion to both the aluminum plate and the film are preferred.
A typical primer excellent in adhesion and corrosion resistance is a phenol-epoxy primer comprising a resol type phenol aldehyde resin derived from various phenols and formaldehyde, and a bisphenol type epoxy resin. A primer containing a resin and an epoxy resin in a weight ratio of 50:50 to 5:95, particularly 40:60 to 10:90. In general, the adhesive primer layer is preferably provided in a thickness of 0.3 to 5 μm.

(Coating of resin film on aluminum plate)
As a method of coating a resin film on an aluminum plate, a method of coating an unstretched film while roll-pressing a heated aluminum plate surface to melt the interface is employed. This unstretched film is made by heating and melting the resin pellets at a temperature 20 to 40 ° C. higher than the melting temperature of the resin using an extruder, and cooling it on the casting roll surface while extruding it from the slits of the T-die. The
Further, in another method, the film-like resin from the T-die type slit is directly and continuously coated on the surface of the heated aluminum plate to be moved and cooled. Any coating method can be applied to the rectangular can lid of the present invention.

(laminate)
In laminating, the time for the film to be laminated to pass through the crystallization temperature range is made as short as possible, and preferably this temperature range is passed within 10 seconds, particularly within 5 seconds. Therefore, only the aluminum material is heated at the time of lamination, and the resin-coated aluminum plate is forcibly cooled immediately after the film lamination. For cooling, direct contact with cold air or cold water or pressure contact of a cooled cooling roller is used. When the film is laminated, the degree of crystal orientation can be relaxed by heating the film to a temperature close to the melting point and performing rapid cooling after lamination.

(Preheating treatment of aluminum plate coated with unstretched film)
In the rectangular can lid of the present invention, it is important to pre-heat-treat the unstretched film-coated aluminum plate, which is a raw material, before forming the can lid. In general, when a metal plate coated with various resin films is subjected to press molding on a can lid or the like, strong adhesion is required so that the coated resin film itself does not crack or peel off from the underlying metal plate. Unstretched film is not oriented because it is not stretched in the vertical and horizontal directions at the time of film formation, and it is said that there is no bias in physical properties in the film surface direction, and it is relatively soft and easy to follow severe processing. ing. Since such an unstretched film has good processability of the film itself, it is often used as a press-molded product by laminating on the surface of a metal plate.
Also in the rectangular can lid of the present invention, it is required to reduce the radius of the four corners of the chuck wall portion 1w of the can lid, and since severe workability is required, an unstretched film excellent in workability is applied. Is. However, even in an unstretched film that is said to have better workability than a biaxially stretched film, each of the four corner corner radii of the chuck wall portion 1w of the square can lid 1 as in the square can lid of the present invention. It has been found that in severe processing such that the thickness becomes 10 mm or less, film wrinkles or film peeling occurs.

  FIG. 3 is a schematic diagram of the appearance of film wrinkles occurring at the four corners of the rectangular can lid of the present invention observed from the side that becomes the inner surface of the can after winding (with the lid turned upside down) It is sectional drawing. 3A is a cross-sectional view of the can lid, and FIG. 3B is a plan view seen from the back side of the can lid. These drawings schematically show how film wrinkles 1s are generated radially from the corner center at the four corners of the seaming panel 1p, and a partially enlarged view is shown in the lower right direction. . Such film wrinkles 1s are also generated at the four corners at the same position on the front side of the can lid. Here, the square can lid corner radius R is the corner radius of the chuck wall 1w that contacts the inner surface of the can barrel side wall.

  FIG.3 (c) is the schematic cross section which expanded the cross section cut | disconnected (it shows by a XX line in a figure) so that the generation | occurrence | production part of the film wrinkle 1s of the corner part shown in FIG.3 (b) may be crossed. As can be seen from FIG. 3 (b), the resin film 12 covered with the aluminum plate 10 is compressed in the surface direction (Y1, Y2 direction) in a wrinkled portion of the film wrinkle 1s, and the resin wrinkles. Unevenness occurs on the film surface. Moreover, some peeling is seen in the interface which touches a metal plate. Film wrinkles generated on the front and back surfaces of the corners of the can lid not only incompletely seal the can lid and can body opening during double winding, but also significantly impair the appearance of the product. To do.

In the present invention, the conditions for preventing film wrinkles generated on the front and back surfaces of the corner portion of the can lid as described above were experimentally found. In the present invention, the aluminum plate coated with an unstretched film is preliminarily heat-treated before processing to adjust the crystallinity of the coated resin film, thereby preventing wrinkles that occur during molding. The following experiment was tried.
First, several can lids having a corner radius R = 5 mm, which is the smallest radius of the can lid corner, were prepared, and the influence of preheating treatment on film wrinkle generation was tested. The wrinkles were visually observed on both sides of the can lid.

  The result is shown in FIG. As can be seen from FIG. 4, under condition 1 where no preheating treatment was performed before processing, the degree of crystallinity was 5%, and wrinkles were generated at the corners. Conditions 2 to 4 were obtained by changing the heating time at 190 ° C., and the heating times were 10 minutes (condition 2), 30 minutes (condition 3), and 40 minutes (condition 4), respectively. When the heat treatment of Condition 2 was performed, the degree of crystallinity was 19%, but wrinkles occurred at the corners. When the heat treatment of Condition 3 was performed, the degree of crystallinity was 30%, and no wrinkles were generated at the corners. Condition 4 was that the heat treatment time was further increased, the crystallinity was as high as 45%, and no wrinkles occurred at the corners.

  Furthermore, the heating temperature was increased to 200 ° C. in order to search for preheating treatment conditions. Conditions 5 to 7 were obtained by changing the heating time at 200 ° C., and the heating times were 2 minutes (condition 5), 10 minutes (condition 6), and 20 minutes (condition 7), respectively. When the heat treatment of condition 5 was performed, the degree of crystallinity was 10%, but wrinkles occurred at the corners. When the heat treatment of Condition 6 was performed, the degree of crystallinity was 20%, and no wrinkles were generated at the corners. Condition 7 was that the heat treatment time was further increased, the crystallinity was as high as 39%, and no wrinkles were generated at the corners.

  As estimated from the experimental results shown in FIG. 4, the crystallinity of the resin film generally increases as the heating conditions are increased and the treatment time is increased. In addition, there is a close relationship between the generation of wrinkles during processing and the crystallinity of the coated resin film, and the minimum crystallinity that does not generate wrinkles at the corners is 20%. Even if the crystallinity is increased (45 %) Wrinkles do not occur.

  That is, when processing the rectangular can lid of the present invention, as a pretreatment that does not cause wrinkles in the corner portion of the can lid, the resin-coated aluminum plate before molding is preheated so that the crystallinity of the resin film is 20% or more. I found that it was necessary. If the degree of crystallinity is 20% or more, wrinkles are not generated at the corners of the can lid, but it is preferable to keep the heat treatment energy accompanied by an increase in the total energy cost of can lid production, so that it is economical. Therefore, the upper limit of the crystallinity without wrinkle generation is set to 40%.

  According to said result, even if the radius of the corner | angular part of a square can lid is made the severest 5 mm, the liquid-proof property in double winding can be improved, without generating film wrinkles. In the rectangular can lid of the present invention, the reason why the corner radius is 5 to 10 mm is that if the corner radius is less than 5 mm, the can lid can be formed. However, since the corner radius is small, double winding with a seaming roll is not possible. This is because it becomes complete and the sealing performance at the corner may not be maintained. On the other hand, when the corner radius R is more than 10 mm, the can lid can be easily molded and double-tightened. However, when the rectangular can lid of the present invention is a can lid such as a battery case, The corner radius also increases, and the volumetric efficiency when a large number of cans are juxtaposed decreases (the gap between the cans increases), and the merit as a rectangular can decreases. Therefore, the corner radius of the can lid in the present invention is defined within a range of 5 to 10 mm.

(Measurement of crystallinity)
In addition, the measuring method of the crystallinity degree of the coat | covered film is as follows. The surface layer of the resin film coated on the aluminum plate was scraped, subjected to a heat treatment at 185 ° C. for 10 minutes and a retort treatment at 110 ° C. for 60 minutes, and then a differential operation calorimeter (DSC) measurement was performed. The measurement was performed using a DSC7-RS manufactured by PERKIN ELMER at a rate of temperature increase of 10 ° C./min. The crystallinity was calculated from the melting peak ΔH obtained by the measurement using the following formula.
Crystallinity (%) = (ΔH (PET) − | ΔHc |) / ΔH (PET) × 100ΔH (PET) = 122.25 J / g

(Double tightening of can lid on can)
A method for attaching the rectangular can lid of the present invention by double-rolling it onto the can body will be described below. FIG. 5 shows a cross-sectional structure before and after double-tightening the rectangular can lid 1 of the present invention to the opening of the rectangular can body 2. As shown in FIG. 5A, first, the chuck wall 1w of the can lid 1 is set in the opening flange 2f of the can body 2 while being inscribed inside the flange 2f. On the inner surface of the sealing panel 1p, an organic compound 20 that serves as a packing that completes the sealing is applied. This organic compound 20 is indispensable for ensuring the double winding of the four corners of the rectangular can and enhancing the leakage resistance.

  As shown in FIG. 5 (b), in the double winding process, the seaming roll 30b is pressed from the outer periphery of the can lid while rotating by applying the seaming chuck 30a to the center panel 1a of the can lid 1. Double-tighten so that the flange 2f is held by the panel 1p and the cover hook 1h. Since the organic compound is present in the double tightening portion, the leakage resistance is more reliable.

  The organic compound 20 is a material having a rubber-like elasticity, and a material conventionally used for improving the sealing performance of a double winding portion or the like is used. For example, styrene butadiene rubber, ethylene propylene rubber, polyisoprene rubber, polyamide resin, polyolefin resin, or a blend of a required diluent, curing agent, or the like is used.

  FIG. 6 shows an embodiment in which a rectangular lid of the present invention prepared using an unstretched polyester-coated aluminum plate is applied to a battery case. FIG. 6 shows an embodiment in which the through hole 3 is provided in the can lid 1 and the electrodes 5 a and 5 b are attached to the through hole 3 via the insulator 4. In this embodiment, two electrodes (5a, 5b) serving as counter electrodes are disposed in the through hole 3 provided in the center portion of the center panel 1a of the can lid 1 via an insulator 4. . The size and arrangement of the electrodes can take a necessary form according to the power generation element member filled therein. That is, when an electrode is also provided on the can bottom, one electrode is provided on each of the top side and the bottom side.

  FIG. 7 shows an embodiment in which a through hole 3 similar to the above is provided in an opening of a rectangular can formed by joining a can body with an electric resistance weld 2y, and an insulator 4 is attached to the through hole 3. Indicates. In this embodiment, the counter electrode is provided separately at both ends of the can body, the electrode 5a is disposed in the through hole 3 at the center of one can lid via an insulator 4, and the other can lid (the same figure). On the lower side, the electrode 5b is arranged.

  Since the unstretched polyester-coated aluminum plate as a raw material is preheated before forming the can lid, and the can lid can be prevented from generating film wrinkles, the corner radius R of the four corners is 10 mm or less. A square can excellent in leakage resistance can be provided because sealing by double winding is ensured. Further, the can lid of the present invention can be suitably used for can lids for various battery cases that require particularly high leakage resistance.

The perspective view of the square can lid of this invention and the battery case which attaches it. Cross-sectional structure diagram of an aluminum plate material coated with a resin film according to an embodiment of the present invention Illustration of film wrinkle generation position and corner radius (R) generated at the corner of the canopy Explanatory drawing of the influence on preheating treatment and film wrinkle generation and crystallinity of the present invention It is explanatory drawing which double-tightens the lid | cover of this invention to a can. It is the embodiment which applied the lid | cover for squares produced using the unstretched polyester covering aluminum plate to the battery case. The embodiment which attached the can lid of this invention to the opening part of the square can formed by joining a can body by the electrical resistance welding part is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Square can lid 1a ... Center panel part 1h ... Cover hook part 1p ... Seaming panel part 1s ... Film wrinkle 1w ... Chuck wall part 2 ... Can barrel 2f ··· Flange 2k ··· Can body opening 2n ··· Neck portion 2y ··· Welded joint 3 ··· Through hole 4 ··· Insulator 5a, b · · · Electrode 10 · · · Aluminum plate 11 ... Surface treatment layer 12 ... Resin film 20 ... Organic compound 30a ... Seaming chuck 30b ... Seaming roll

Claims (2)

A lid attached to the flange provided in the opening that forms the square can by double tightening via an organic compound,
The lid is made of an aluminum plate having at least an inner surface coated with an unstretched polyester film whose crystallinity is in the range of 20 to 40% by preheating before molding,
A square can lid characterized in that radii (R) of chuck wall corner portions at the four corners of the lid attached to the opening of the square barrel by double winding are in the range of 5 to 10 mm . The square can lid according to claim 1 , wherein the square can is a battery case, and a through hole is provided in a central portion of the lid, and an electrode is attached to the through hole via an insulator. .

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