JP4960215B2 - Metal foil negative electrode current collector processing roller and metal foil negative electrode current collector processing method - Google Patents

Description

The present invention relates to a metal foil negative electrode current collector processing roller and a metal foil negative electrode current collector processing method for obtaining a negative electrode current collector for a lithium secondary battery . More specifically, the present invention mainly relates to an improvement in a metal material constituting a roller for processing a metal foil negative electrode current collector in which a plurality of concave portions are formed on the surface.

Conventionally, in order to form a convex portion on the surface of a metal foil having a thickness of several tens of microns, a plating method, an etching method, or the like is generally used. However, when these methods are used to form several tens to several hundreds of convex portions having a size of a micron unit per 1 cm ² of the surface of the metal foil, precision processing having many steps is performed, and complicated operations are performed. Is necessary and takes a long time. Nevertheless, the defective product rate cannot be reduced sufficiently. The treatment of the waste liquid that occurs with the use of a plating solution, an etching solution, or the like also becomes a problem. Moreover, the convex part formed by these methods does not have sufficient bonding strength with the metal foil, and often peels off from the metal foil when stress is applied from the outside. Therefore, it is difficult to say that the plating method, the etching method and the like are industrially advantageous methods for producing a metal foil having a convex portion on the surface.

In addition, a technique is widely used in which a metal plate is passed through a pressure nip formed by a pair of rollers in pressure contact, and the metal plate is pressed. A typical example of such a pressure forming technique is cold rolling of steel.
For example, a dull roll has been proposed in which a crater-like recess and a raised portion that swells along the edge of the crater-like recess are formed on the surface (see, for example, Patent Document 1). The dull roll is used to apply a so-called dull surface to the surface of the cold-rolled steel sheet between the cold rolling process and the annealing process. Thereby, when the annealing process is batch annealing, seizure of the steel sheet is prevented. Moreover, when an annealing process is continuous annealing, meandering of a steel plate is prevented when conveying a steel plate within an annealing furnace.

  Further, in Patent Document 1, when the bulge portion on the surface of the dull roll is strongly pressed against the steel plate surface, a local plastic flow of the steel plate material occurs on the surface of the steel plate, the steel plate material flows into the concave portion of the dull roll, and the steel plate is rough. It is described that it is faced. Further, in Patent Document 1, while rotating a roll having a smooth surface, a laser pulse is projected onto the roll surface, the roller surface is melted regularly, and crater-like recesses are regularly formed to manufacture a dull roll. It is described to do.

However, Patent Document 1 only discloses a technique for increasing the surface roughness of a cold-rolled steel sheet having a thickness of several hundred μm to several mm, and the surface of the metal foil having a thickness of only several tens of μm. There is no disclosure about the formation of convex portions. In Patent Document 1, since there is no particular described for the material of the dull roll, Daruro Le is considered to be formed by a common material. A general material is a steel material harder than the steel plate cold-rolled, for example. The dull roll made of the above material cannot be used for forming a convex portion on an industrial scale because the crater-like concave portion on the surface is easily lost due to wear or the like. Further, when a dull roll is manufactured by applying laser processing to the roll of the material, a concave portion having a desired opening shape cannot be formed. For example, when an opening having a rhombus shape is to be formed, the opening edge of the recess is melted by the residual heat of the laser and becomes elliptical.

  In addition, a rolling roll has been proposed in which irregularities are formed on the surface, the depth of the concave portion is 5 to 100 μm, and the ratio of the total area of the convex tip end surface to the total surface area is 10 to 80% (for example, , See Patent Document 2). However, the technique of Patent Document 2 also applies a dull surface to the surface of a cold-rolled steel sheet having a thickness of several hundred μm to several mm, and forms a protruding convex portion on the surface of a metal foil having a thickness of several tens of μm. Not what you want. Since there is no special description about the material of a rolling roll in patent document 2, the rolling roll of patent document 2 cannot be utilized for the convex part formation on an industrial scale similarly to the dull roll of patent document 1, and A recess having a desired opening shape cannot be formed.

  Also, a rolling device has been proposed that includes a first work roll in which a plurality of annular recesses (projection forming annular grooves) extending in the circumferential direction are formed and a second work roll having a smooth circumferential surface (for example, a patent). Reference 3). In the rolling apparatus of Patent Document 3, the first work roll and the second work roll are pressed against each other so that their axes are parallel to each other to form a pressure nip portion. By passing a long metal plate-like material through the pressure nip, a plurality of protrusions are formed on one surface in the thickness direction of the plate-like material, and a metal plate for producing a flat tube is obtained. A flat tube can be obtained by bending the metal plate for manufacturing the flat tube. This flat tube is used as a refrigerant flow tube for a condenser.

  Patent Document 3 proposes a cemented carbide as the material of the first work roll. Furthermore, cemented carbides such as JIS V10-60 are described. However, the technique of Patent Document 3 does not target a metal foil having a thickness of several tens of μm. Further, in Patent Document 3, only the engraving is described as a method for forming the annular recess, and there is no description about laser processing. In the engraving, it is very difficult to form a plurality of concave portions having a dimension of a micron unit at intervals of about 10 to 50 μm. Further, even when a large number of micron concave portions are formed in the cemented carbide by laser processing, the opening shape and the opening diameter of the concave portions are not necessarily uniform. Furthermore, in Patent Document 3, cemented carbide is only used to prevent the bottom surface of the annular recess from being worn.

  On the other hand, a technique for making holes in electronic parts such as ceramic green sheets and circuit boards by laser processing has been well known (see, for example, Patent Document 4). That is, it is often performed to form a recess on the surface of a ceramic layer, a resin layer, or the like by using laser processing. However, there is no proposal or report on the technical idea of using laser processing to form hundreds to tens of millions of recesses having a micron-size dimension on a metal surface. In addition, when a large number of the recesses are formed on a metal surface such as general stainless steel by laser processing, the opening shape and the opening diameter of the recesses on the metal surface are not uniform. Furthermore, there is a problem that the mechanical strength, wear resistance, and the like of the formed recess are reduced, and wear, deformation, breakage, and the like are likely to occur.

Furthermore, it is a common practice to press-mold a resin sheet using a ceramic roller having a plurality of recesses formed on the peripheral surface, and to emboss the surface of the resin sheet. However, when the metal foil is pressure-molded using a ceramic roller having a concave portion formed on the peripheral surface, many cracks, chips, cracks, etc. are generated on the peripheral surface of the ceramic roller, and the metal foil cannot be continuously press-molded.
JP-A-63-10013 Japanese Patent Laid-Open No. 10-166010 JP-A-2005-997 JP 2005-111524 A

An object of the present invention is a metal foil processing roller in which a plurality of recesses are formed on the peripheral surface. Even if a metal foil for a negative electrode current collector is processed on an industrial scale, the recesses are worn, deformed, etc. it is less likely to occur, is to provide an efficient roller metal foil anode collector processing can be produced and the metal foil anode collector processing method using the same metal foil having a convex portion.

  The inventors of the present invention have intensively studied to solve the above problems. In the process, it was found that two of the various characteristics of the metal material, that is, Rockwell hardness and bending strength, have a great influence on the opening shape and opening diameter of the recess during laser processing. The present inventors have further studied based on this finding. As a result, when forming recesses in units of microns on a roller surface made of a metal material having a specific Rockwell hardness and bending strength, the number of recesses is a large number ranging from hundreds to tens of millions. However, it was found that variations in the opening shape and opening diameter are very small, and a substantially uniform recess can be formed. Further, it has been found that the concave portion has high durability against external stress such as frictional force, and it is difficult for wear, deformation, breakage and the like to occur, and the present invention has been completed.

That is, according to the present invention, a plurality of recesses are formed on the peripheral surface by laser processing, and the peripheral surface is pressed against a metal foil that is a copper foil or a copper alloy foil, and a plurality of columnar heights of 4 μm or more are formed on the metal foil surface . forming a convex portion, a metal foil anode collector machining roller to obtain a negative electrode current collector for a lithium secondary battery, a surface layer portion at least the recess is formed, the Rockwell hardness The present invention relates to a metal foil negative electrode current collector processing roller made of a metal material having HRA of 81.2 to 90.0 on an A scale and a bending strength of 3 GPa to 6 GPa.

Concave cross-sectional shape in a direction perpendicular to the peripheral surface of the metal foil anode collector machining rollers toward the bottom surface of the recess from a metal foil machining roller the circumferential surface, slowly or continuously smaller cross-sectional width it is preferred Ru tapered shape der.
The opening shape of the recesses on the peripheral surface of the metal foil negative electrode current collector processing roller is preferably approximately circular, approximately elliptical, approximately diamond-shaped, or approximately regular polygonal.
The opening diameter of the recess in the peripheral surface of the metal foil negative electrode current collector processing roller is preferably 1 μm to 35 μm.
The pitch of the concave portions in the roller axial direction on the peripheral surface of the metal foil negative electrode current collector processing roller is preferably 4 μm or more.

The Rockwell hardness of the metal material is HRA 83.9 to 89 on the A scale, and the bending strength of the metal material is preferably 3.3 GPa to 5.5 GPa.
The metal material is preferably at least one refractory metal material selected from the group consisting of cemented carbide, cermet, high-speed steel, die steel, and forged steel.
The metal negative electrode current collector processing roller is preferably used so that the bottom surface of the recess does not contact the surface of the metal foil.
In the present invention, at least one of the press contact nip portion formed by press contact with a pair of rollers made of a metal foil negative electrode current collector processing roller having a plurality of recesses formed by laser processing on the peripheral surface A metal foil negative electrode current collector for supplying a negative electrode current collector for a lithium secondary battery by supplying a metal foil which is a foil or a copper alloy foil to form a columnar convex part having a height of 4 μm or more on the surface of the metal foil In the electric material processing method, at least the surface layer portion where the concave portion of the metal foil negative electrode current collector processing roller is formed has a Rockwell hardness of HRA of 81.2 to 90.0 and a bending strength. Ri Do metallic material is 3GPa～6GPa, wherein the cross-sectional shape of the recess in a direction perpendicular to the peripheral surface, wherein the circumferential surface toward the bottom surface of the recess, cross-sectional width is gradually or successively smaller taper wherein the shape der Rukoto Ru engages the metal foil anode collector processing method for.
In the said metal foil processing method, it is preferable that the height of a convex part is 4 micrometers or more.

The roller for metal foil processing of the present invention has a plurality of recesses formed on its peripheral surface by laser processing. In the metal foil processing roller of the present invention, by including a metal material having Rockwell hardness and bending strength in the above ranges in at least the surface layer portion forming the recess, the opening shape and the opening diameter on the roller peripheral surface are substantially reduced. Can be evenly aligned. Moreover, it can adjust to arbitrary opening shapes and opening diameters. For example, it becomes possible to form a recess having an opening diameter of several microns to several tens of microns. Further, it is possible to form a concave portion having an opening shape such as a substantially perfect circle, a substantially diamond shape, or a substantially regular polygon. Furthermore, it becomes possible to form such recesses at a pitch of about 10 to 50 μm.
Moreover, this recessed part has the very high durability with respect to the stress from the outside, and also is excellent in the mold release property with the convex part of the metal foil which grows in the internal space of a recessed part. Therefore, even if the processing of the metal foil is carried out industrially continuously, it is difficult for wear and deformation to occur, and a convex portion having substantially the same shape can be formed stably and efficiently.

  The roller for processing a metal foil of the present invention is, for example, for pressure-molding a metal foil to obtain a metal foil having a convex portion on one or both surfaces in the thickness direction (hereinafter referred to as “convex-forming metal foil”). Used for. Specifically, a molding apparatus including the metal foil processing roller of the present invention and a metal roller having a smooth surface is used. The metal foil processing roller and the metal roller are pressed against each other so that their axes are parallel to each other to form a pressure nip portion. By supplying and passing the metal foil so that the surface on which the convex portion is to be formed comes into contact with the peripheral surface of the metal foil processing roller, the convex-formed metal foil can be obtained. . Moreover, the convex part formation metal foil which has a convex part on both surfaces can be obtained by pressing and using two rollers for metal foil processing.

  The metal foil that is pressure-formed by the metal foil processing roller of the present invention is not particularly limited, and examples include copper foil, copper alloy foil, tin foil, stainless steel foil, aluminum foil, lead foil, nickel foil, and zinc foil. . Moreover, it is preferable that the metal foil pressure-molded by the metal foil processing roller of the present invention has such characteristics that the grain boundary is easily deformed and the annealing temperature is low. The thickness of the metal foil is not particularly limited, but is preferably 10 to 100 μm, more preferably 10 to 50 μm.

The convex part formation metal foil obtained from copper foil, copper alloy foil, etc. using the metal foil processing roller of the present invention can be suitably used as, for example, a negative electrode current collector in a lithium secondary battery. A columnar body containing a negative electrode active material and functioning as a negative electrode active material layer is formed on the surface of each convex portion of the convex portion-forming metal foil obtained from copper foil or copper alloy foil by vacuum deposition. At this time, as the negative electrode active material, for example, silicon, silicon oxide, silicon-containing alloy, silicon compound, tin, tin oxide, tin-containing alloy, tin compound, or the like can be used. By forming the columnar negative electrode active material layer on the convex surface, the stress generated as the negative electrode active material expands and contracts when lithium ions are occluded and released is absorbed. Deformation and peeling of the negative electrode active material layer from the negative electrode current collector are prevented. As a result, a lithium secondary battery excellent in charge / discharge cycle characteristics, long-term safety, and the like can be obtained.
Moreover, the metal foil for convex part formation obtained by this invention can be used conveniently also for the metal foil or metal layer in a flexible printed wiring board, the metal substrate for lead frames, etc., for example.

The metal foil processing roller of the present invention has two features. The first feature is that a plurality of recesses are formed on the peripheral surface. The second feature is a metallic material Tona Rukoto having surface layer portions a specific characteristic which is formed of at least the recess.
The concave portion is a space region having an opening in the peripheral surface (hereinafter simply referred to as “roller peripheral surface”) of the metal foil processing roller of the present invention, and being recessed or recessed in the roller rather than the roller peripheral surface. The bottom surface of the recess may be a substantially flat plane or may be a dome shape.

Each recess is normally formed independently so as not to be connected to other recesses adjacent to it, but is not limited thereto, and may be partially connected and integrated, or connected to the whole. It may be integrated. Preferably, it forms independently so that each recessed part may not be connected.
The shape of the opening in the roller peripheral surface of the recess is not particularly limited, but is preferably approximately circular, approximately elliptical, approximately diamond-shaped, approximately regular polygonal, or the like. The regular polygon is preferably a 3-8 octagon, more preferably a 4-6 hexagon.

  Although the opening diameter in the roller peripheral surface of a recessed part is not restrict | limited in particular, Preferably it is 1 micrometer-35 micrometers, More preferably, it is 2-30 micrometers. If the opening diameter is less than 1 μm, it is difficult to make the opening diameters of the individual recesses substantially uniform. When the opening diameter exceeds 35 μm, it is not suitable for surface processing of a metal foil having a thickness of about several tens of μm. In addition, the stress applied when the metal foil is pressure-formed may cause wear or deformation in the recess. When the opening shape is approximately circular, approximately elliptical, or approximately regular polygonal, the opening diameter is the length of the diameter of the smallest perfect circle that encloses the circle, ellipse, or regular polygon. When the opening shape is approximately rhombus, the opening diameter is the length of the longer diagonal line of the rhombus diagonal lines.

The depth of the recess is not particularly limited, and can be appropriately selected according to, for example, the height of the protrusion to be formed on the surface of the metal foil, but preferably 0.2 to 1.5 times the opening diameter, Preferably 0.3 times the opening diameter to 1. 2 times . If the depth of the recess is less than 0.2 times the opening diameter, it may not be possible to form a protrusion having a uniform size and shape on the surface of the metal foil. In addition, it is extremely difficult to form the recess so that the depth of the recess exceeds 1.5 times the opening diameter by the laser processing method. Also, the cutting method requires a great deal of time or is substantially impossible to form the recess. The depth of the concave portion is the length of a perpendicular drawn from the most concave point on the bottom surface of the concave portion to the roller peripheral surface assumed to exist at the opening of the concave portion.

  The pitch at which the recesses are formed on the roller peripheral surface is not particularly limited in both the axial direction (longitudinal direction) and the circumferential direction of the roller. The pitch in the axial direction of the recesses can be appropriately selected according to the opening diameter of the recesses, the opening shape, the length of the roller, the design value of the projection-forming metal foil to be obtained, and preferably 4 μm or more, Preferably it is 8-30 micrometers, Most preferably, it is 15-30 micrometers. When the pitch in the axial direction of the recesses is less than 4 μm, the recesses are easily connected by the laser processing method. Therefore, the area of the roller surface partitioning the recesses becomes extremely small, and the threshold between the recesses may be deformed by the stress applied when the metal foil is pressed. . The upper limit value of the pitch in the axial direction may be appropriately selected according to the length of the roller.

  Further, the pitch in the circumferential direction of the recesses can be appropriately selected according to the opening diameter of the recesses, the opening shape, the circumferential length of the roller, the design value of the convex-formed metal foil to be obtained, etc. Is 4 μm or more, more preferably 5 to 20 μm. When the circumferential pitch of the recesses is less than 4 μm, the recesses are easily connected to each other by the laser processing method. Therefore, the area of the roller surface partitioning the recesses becomes extremely small, and the threshold between the recesses may be deformed by the stress applied when the metal foil is pressed. The upper limit value of the pitch in the circumferential direction may be appropriately selected according to the circumferential length of the roller.

  In the present specification, the pitch in the axial direction is a distance (length) between two parallel straight lines extending in the circumferential direction through the centers of two recesses adjacent in the axial direction. The circumferential pitch is a distance (length) between two parallel straight lines extending in the axial direction through the centers of two concave portions adjacent in the circumferential direction. The center of the recess means the center of the opening of the recess. The center of the opening is the center of the smallest perfect circle that encloses the circle, ellipse, or regular polygon when the shape of the opening of the recess is substantially circular, substantially elliptical, or substantially regular polygonal. Moreover, when the opening shape of a recessed part is substantially rhombus, the intersection of two diagonal lines is the center of opening.

The cross-sectional shape of the recess in the direction perpendicular to the peripheral surface of the roller is preferably a tapered shape in which the cross-sectional width gradually or continuously decreases from the roller peripheral surface toward the bottom surface of the recess. When the concave portion has a tapered cross-sectional shape, when the convex portion is formed on the surface of the metal foil by pressure forming of the metal foil, the releasability between the concave portion of the roller peripheral surface and the convex portion of the metal foil is remarkable. It improves, and defects such as deformation of the convex part are very unlikely to occur.
The concave portion is formed by laser processing, and details of the laser processing will be described later.

Metal foil machining roller of the present invention, the surface layer portion is formed of at least recesses, Tona Ru specific metal material. This metal material has a Rockwell hardness of HRA 81.2 to 90.0, preferably HRA 83.9 to 89.0 on an A scale, and a bending strength of 3 GPa to 6 GPa, preferably 3.3 GPa to 5.5 GPa. It is.

  If the Rockwell hardness is A scale and less than HRA81.2, even if the metal foil is pressed, the roller will flatten or bend in the axial direction. May be insufficient, and the height of the convex portion may be lowered, or the convex portion having a size and shape that is substantially close to the design value may not be formed uniformly. Therefore, there is a possibility that a desired convex-formed metal foil cannot be obtained. Further, the surface of the metal foil processing roller is worn, and the recesses are easily worn and deformed. On the other hand, if the Rockwell hardness exceeds HRA 90.0 on the A scale, the concave portion of the metal foil processing roller is likely to be cracked, chipped, cracked, etc. There is a possibility that the pressure forming of the metal foil becomes insufficient, such as forming a part.

In this specification, the Rockwell hardness (HRA) is a value calculated from the following formula based on JIS Z-2245.
HRA = 100-0.5h
[In the formula, h represents the difference in penetration depth h of the diamond indenter. ]
The difference in penetration depth h of the diamond indenter is obtained as follows. Using a diamond indenter with a tip radius of curvature of 0.2 mm and a cone angle of 120 °, an initial load of 98.07 N is applied to the sample surface, then a test load of 588.4 N is applied, and the initial load is applied again. The penetration depth of the diamond indenter at two initial loads before and after is obtained, and the difference is obtained as a difference h of the penetration depth of the diamond indenter.

  Further, if the bending strength is less than 3 GPa, the concave portion of the metal foil processing roller is likely to be cracked, chipped, cracked, etc., and the shape of the convex portion is deformed or the convex portion is formed at an unnecessary position. For example, the metal foil may be insufficiently pressed. Accordingly, the metal foil processing roller cannot withstand long-term use, and the formation of convex portions becomes insufficient even in the initial use, which may increase the defective product rate. On the other hand, if the bending strength exceeds 6 GPa, even if the metal foil is pressure-molded, the roller is flattened or bent in the axial direction. There is a possibility that the height of the convex portion becomes low or the convex portion having a size and shape almost close to the design value cannot be formed uniformly. Further, the wear resistance of the surface of the metal foil processing roller is lowered, and the recesses are easily worn and deformed. In addition, after the metal foil is formed, the mold releasability between the metal foil processing roller and the metal foil is lowered, and there is a possibility that problems such as the metal foil being caught by the metal foil processing roller may occur.

In this specification, the bending strength is a value measured as follows based on JIS Z-2248. As the test piece, a round bar having a diameter D of 13 mm and a length of 300 mm is used. The bending strength measurement test was performed as a three-point bending test using a universal testing machine and a bending test apparatus attached thereto, with the distance L between the fulcrums set to 200 mm. Assuming that the load when the sample breaks is the maximum load W _max , the bending strength σ _b is calculated from the following equation.
σ _b = 8 W _max L / πD ³

  In the present invention, as the metal material having Rockwell hardness and bending strength in the predetermined numerical range shown above, at least one high material selected from the group consisting of cemented carbide, cermet, high-speed steel, die steel and forged steel is used. It is preferable to use a melting point metal material. Among these, cemented carbide, high-speed steel, forged steel, and the like are more preferable, and forged steel is particularly preferable. A metal material belonging to these refractory metal materials and having a predetermined Rockwell hardness and bending strength is capable of laser processing, and is extremely excellent in shape and size reproducibility. In addition, by forming recesses in such metal materials using laser processing, wear, deformation, and breakage of recesses are very unlikely to occur even when metal foil molding is repeated, and long-term durability Is expensive. The workpiece may contain one or more metal materials.

As a specific example of the cemented carbide, a known one can be used. For example, cemented carbide obtained by sintering carbide particles of metals in groups 4A, 5A, and 6A of a periodic table using a metal binder such as Fe, Co, and Ni. An alloy etc. are mentioned. Specific examples of the cemented carbide include, for example, WC—Co, WC—Cr ₃ C ₂ —Co, WC—TaC—Co, WC—TiC—Co, WC—NbC—Co, WC—TaC. -NbC-Co, WC-TiC-TaC-NbC-Co, WC-TiC-TaC-Co, WC-ZrC-Co, WC-TiC-ZrC-Co, WC-TaC-VC-Co , WC-TiC-Cr ₃ C ₂ -Co, WC-TiC-TaC, WC-Ni, WC-Co-Ni, WC-Cr ₃ C ₂ -Mo ₂ C-Ni, WC-Ti ( C, N)-Tac system, WC-Ti (C, N ) based tungsten carbide based cemented carbide such as, etc. Cr ₃ C ₂ -Ni systems.

As a specific example of the cermet, a known cermet can be used. For example, TiC—Ni, TiC—Mo—Ni, TiC—Co, TiC—Mo ₂ C—Ni, TiC—Mo ₂ C—ZrC—Ni , TiC—Mo ₂ C—Co, Mo ₂ C—Ni, Ti (C, N) —Mo ₂ C—Ni, TiC—TiN—Mo ₂ C—Ni, TiC—TiN—Mo ₂ C -Co _{series, TiC-TiN-Mo 2 C} -TaC-Ni _{-based, TiC-TiN-Mo 2 C} -WC-TaC-Ni -based, TiC-WC-Ni type, Ti (C, N) -WC -Ni system , TiC—Mo system, Ti (C, N) —Mo system, boride system (MoB—Ni system, B ₄ C / (W, Mo) B ₂ system, etc.), and the like. Among these, Ti (C, N) —Mo ₂ C—Ni, TiC—TiN—Mo ₂ C—Ni, TiC—TiN—Mo ₂ C—Co, TiC—TiN—Mo ₂ C—TaC— _{Ni-based, TiC-TiN-Mo 2 C} -WC-TaC-Ni -based, Ti (C, N) -WC -Ni -based, Ti (C, N) -Mo titanium carbonitride based cermet, such systems are preferred.

  High-speed steel is a material obtained by adding a metal such as molybdenum, tungsten, or vanadium to iron and further heat-treating it to increase the hardness. As a high-speed steel, a known steel can be used. For example, a high-speed steel containing iron as a main component and containing carbon, tungsten, vanadium, molybdenum and chromium, iron as a main component and carbon, tungsten, vanadium, molybdenum, cobalt and High-speed steel containing chromium, high-speed steel mainly containing iron and containing carbon, vanadium, molybdenum and chromium, high-speed steel mainly containing iron and containing silicon, manganese, chromium, molybdenum and vanadium, and iron High-speed steel containing carbon, silicon, manganese, chromium, molybdenum and vanadium as a component and high-speed steel containing iron, the main component and containing carbon, silicon, manganese, chromium, molybdenum, tungsten, cobalt, and vanadium .

  As the die steel, known ones can be used, for example, die steel containing iron, carbon, tungsten, vanadium, molybdenum and chromium, die steel containing iron, carbon, vanadium, molybdenum and chromium, iron, carbon, silicon , Manganese, sulfur, chromium, molybdenum and / or tungsten, vanadium, nickel, copper, and die steel containing aluminum.

Forged steel is a steel ingot produced by casting molten steel in a mold or a steel piece produced from the steel ingot, and forged or rolled and forged with a press and a hammer, and then heat-treated. It is a material manufactured by Known forged steel can be used, for example, forged steel containing iron as a main component and containing carbon, chromium and nickel, forged steel containing iron as a main component and containing silicon, chromium and nickel, nickel, chromium and molybdenum. Forged steel containing, forged steel containing iron as its main component and containing carbon, silicon, manganese, nickel, chromium, molybdenum and vanadium, forged steel containing iron as its main component and containing carbon, silicon, manganese, nickel, chromium and molybdenum, etc. Is mentioned.
In these refractory metal materials, a metal material exhibiting a predetermined Rockwell hardness and bending strength can be obtained by appropriately selecting the composition of the contained components. Moreover, about the high melting-point metal material which heat-processes in manufacturing processes, such as forged steel, the material which has desired Rockwell hardness and bending strength can be obtained by selecting heat processing temperature suitably.

In the metal foil machining roller of the present invention, the thickness of the surface layer portion made of a metal material exhibiting a predetermined Rockwell hardness and transverse rupture strength is not particularly limited, preferably, is about 5 to 50 mm.
When the metal material is a refractory metal material, the surface layer portion as described above can be produced, for example, by shrink-fitting or cold-fitting a refractory material cylinder to the core roller. By shrink fitting, a high melting point material cylinder is made so that the inner diameter of the high melting point material cylinder is slightly smaller than the outer diameter of the core roller, and the high melting point material cylinder is warmed and expanded. It fits into the roller. Further, the cold fitting means that a core roller contracted by cooling is fitted into a cylinder made of a high melting point material so that the inner diameter of the cylinder made of the high melting point material is slightly smaller than the outer diameter of the core roller. It is. For example, a roller made of stainless steel or iron can be used as the core roller.
In addition, the roller for metal foil processing of this invention may be comprised with the metal material which not only the surface layer part but the whole shows predetermined Rockwell hardness and bending strength.

The concave portion present on the peripheral surface of the metal foil processing roller of the present invention is formed by laser processing. That is, a conventional drilling method using a laser can be used to form the recess. For laser processing, for example, a laser processing apparatus including a roller rotating device, a laser oscillator, a processing head, a light guide path, a mask portion, and an actuator can be used.
The roller rotating device includes, for example, a roller support base and a driving device. The roller support base supports a roller having at least a surface layer portion containing a metal material having a predetermined Rockwell hardness and a bending strength and having no concave portion formed on the peripheral surface thereof, so as to be rotatable about its axis. The drive device rotates a roller (hereinafter referred to as a “recess-forming roller”) supported by a roller support base around its axis.

The laser oscillator is a device that outputs laser light. As the laser oscillator, a known laser oscillator can be used. For example, a solid-state laser oscillator (Nd: YAG laser, Nd) using a laser medium in which neodymium ions are mixed into a YAG crystal (yttrium, aluminum, garnet) or a YVO ₄ crystal. : YVO ₄ laser). In addition, a carbon dioxide laser, an excimer laser, etc. can also be used.
The output of the laser oscillator is, for example, 50 mW to 200 W. The frequency of the laser light is preferably 100 Hz to 100 kHz. The irradiation time of the laser light is not particularly limited, but is preferably 10 ps to 200 ns per time. When the irradiation time is less than 10 ps, heat conduction due to laser light irradiation does not occur, and only one layer of atoms can be removed, and the formation of the recesses may be insufficient. On the other hand, if it exceeds 200 ns, the laser beam may sweep the surface of the recess forming roller due to the rotation of the recess forming roller.

  The processing head is a member provided on the downstream side of the light guide in the laser beam output direction by the laser oscillator. The processing head collects the laser beam output from the laser oscillator and sent through the light guide path and irradiates the outer peripheral surface of the recess forming roller. The processing head includes, for example, a condenser lens. The condensing lens is provided so as to be orthogonal to the path of the laser light, condenses the laser light sent through the light guide path, and irradiates the outer peripheral surface of the recess forming roller. The focal length of the condenser lens is not particularly limited, but is preferably selected from the range of 5 mm to 200 mm. In addition, an assist gas is introduced into the processing head. Examples of the assist gas include oxygen, nitrogen, helium, argon, and a mixed gas of two or more of these. What is necessary is just to select the pressure of assist gas from the range of 0.1 MPa-1 MPa, for example.

  The light guide is a member that is provided on the downstream side of the laser oscillator in the laser light output direction of the laser oscillator and guides the laser light output from the laser oscillator to the machining head. The light guide path includes, for example, a plurality of reflection mirrors. By arranging a plurality of reflection mirrors at appropriate positions, the laser light is reflected by the reflection mirror and guided to the processing head. Of the plurality of reflection mirrors, the reflection mirror that is closest to the processing head and directly guides the laser beam to the processing head is provided so as to be able to reciprocate so as to be interlocked with the reciprocation of the processing head.

  The mask portion is a member that is provided in the middle of the light guide path and shapes the contour of the laser light into a desired shape. A laser passage hole, which is a through hole having the same opening shape as the concave portion to be formed, is formed in the mask portion. The contour of the laser beam that has passed through the laser passage hole is shaped into the opening shape of the laser passage hole, and the same image as the opening shape of the laser passage hole is formed on the outer peripheral surface of the recess forming roller by the condenser lens of the processing head. The That is, the opening shape of the laser passage hole becomes the opening shape of the recess.

The actuator is provided vertically below the laser oscillator, the processing head, the light guide path, and the mask portion, and supports these devices and members integrally and reciprocally. The actuator reciprocates these devices and members in parallel with the longitudinal direction of the recess forming roller.
Such laser processing apparatuses are widely commercially available. Even in a laser processing apparatus that does not include a roller rotating device, laser processing for forming a recess can be performed by mounting the roller rotating device at a predetermined position.

The laser processing apparatus, by morphism continuously or intermittently irradiation with a laser beam for forming recesses rollers circumference, recesses are formed. When the concave portion is formed, the concave portion forming roller is rotated or the machining head is moved in the longitudinal direction of the concave portion forming roller by the actuator to newly form the concave portion. By repeating this operation, a concave portion is formed in a desired region of the concave portion forming roller, and the metal foil processing roller of the present invention is obtained.
When the recess is formed by laser processing, a ridge may be formed along the edge of the opening on the roller peripheral surface of the recess. Such ridges are preferably removed by, for example, polishing. Polishing can be performed according to a known method. For example, the diamond particles used as an abrasive and a polishing apparatus using with a polishing pad, is carried out under supply of media bodies, such as water.

  Next, the production of the convex-formed metal foil using the metal foil processing roller of the present invention will be specifically described. FIG. 1 is a side view schematically showing the configuration of the metal foil processing apparatus 10. FIG. 2 is an enlarged perspective view showing a configuration of a main part (processing means 4) of the metal foil processing apparatus 10 shown in FIG. FIG. 3 is a diagram showing the configuration of the metal foil processing roller 1. FIG. 3A is a perspective view showing the appearance of the metal foil processing roller 1. FIG. 3B is an enlarged perspective view showing the surface region 1x of the metal foil processing roller 1 shown in FIG.

The convex portion forming metal foil 2 is a metal foil having a convex portion formed on the surface, and can be manufactured by, for example, the metal foil processing apparatus 10 shown in FIG. The metal foil processing apparatus 10 includes a metal foil supply unit 3, a processing unit 4, and a metal foil winding unit 5.
The metal foil supply means 3 is specifically a metal foil supply roller. The metal foil supply roller is pivotally supported by a support means (not shown) so as to be rotatable around an axis. A metal foil 8 is wound around the peripheral surface of the metal foil supply roller. This metal foil 8 is supplied to the pressure nip 6 of the processing means 4.

  The processing means 4 includes two metal foil processing rollers 1 as shown in FIGS. 1 and 2. The two metal foil processing rollers 1 are pressed against each other so that their axes are parallel to each other. Thereby, the press-contact nip part 6 is formed. The press-contact nip 6 can pass a thin sheet-like material such as a metal foil 8. Each of the metal foil processing rollers 1 is rotatably supported by a support means (not shown) and is rotatably driven around an axis by a drive means (not shown). Both of the two metal foil processing rollers 1 may be drive rollers, or one may be a drive roller and the other may be a driven roller that rotates as the drive roller rotates. In order to prevent the metal working roller 1 from being bent and deformed, a back roller (not shown) is brought into pressure contact with each metal working roller 1. The metal processing roller 1 and the backup roller have mutually parallel axes. By rotating the two metal foil processing rollers 1, the metal foil 8 is guided from the inlet to the outlet of the press-contact nip 6, and the metal foil 8 is pressed. Thereby, the convex part formation metal foil 2 in which the convex part 9 was formed in the surface of the metal foil 8 is obtained.

The metal foil processing roller 1 is a roller according to the present invention in which a plurality of recesses 1a are formed on a peripheral surface.
In this embodiment, the arrangement pattern of the recesses 1a on the circumferential surface of the metal foil processing roller 1 is as follows. As shown in FIG. 3 (b), a row in which a plurality of recesses 1 a are connected at a pitch P ₁ in the longitudinal direction of the metal foil processing roller 1 is defined as one row unit 7. The plurality of row units 7 are arranged at a pitch P ₂ in the circumferential direction of the metal foil processing roller 1. The pitch P ₁ and the pitch P ₂ can be set arbitrarily. In the circumferential direction of the metal foil processing roller 1, one row unit 7 and the adjacent row unit 7 are arranged so that the recesses 1 a are displaced in the longitudinal direction of the metal foil processing roller 1. .
In this embodiment, the longitudinal displacement of the recess 1a is a 0.5P _1, without being limited thereto, it is possible to arbitrarily set. Further, in the present embodiment, the opening shape of the recess 1a on the circumferential surface of the metal foil processing roller 1 is substantially circular, but is not limited to this, and is, for example, substantially elliptical, substantially rhombus, substantially equilateral triangle, It may be a square, a substantially regular hexagon, a substantially regular octagon, or the like.

The cross section of the recess 1a in the direction perpendicular to the peripheral surface of the metal foil processing roller 1 has a width in the direction parallel to the peripheral surface of the metal foil processing roller 1 from the peripheral surface of the metal foil processing roller 1 to the bottom of the recess 1a. It has a taper shape that gradually decreases toward. Thereby, the release property from the roller 1 for metal foil processing of the convex part formation metal foil 2 after completion | finish of press molding improves.
The diameter of the metal foil processing roller 1 is not particularly limited, but is preferably about 30 mm to 200 mm. The pressure contact pressure (linear pressure) of the two metal foil processing rollers 1 is not particularly limited, but is preferably about 5 kN · cm to 20 kN · cm.

In the present embodiment, the two rollers forming the press-contact nip 6 are the metal foil processing roller 1 of the present invention, but the present invention is not limited to this. For example, one of the two rollers may be the metal foil processing roller 1 of the present invention, and the other may be a roller having a smooth surface without forming a recess on the surface. In that case, a convex portion-forming metal foil having a convex portion formed on one surface in the thickness direction is obtained.
Further, as described above, the metal foil 8 is compressed by passing it through the pressure nip 6 to form a sealed space surrounded by the concave portion 1a and the surface of the metal foil 8, and in this sealed space, air is sealed. Remains. When the pressing force (pressure contact pressure) applied to the metal foil 8 by the metal foil processing roller 1 is within the appropriate range described above, this sealed space is maintained while the metal foil 8 is processed, and the recess 1a The bottom surface and the surface of the metal foil 8 are kept in a non-contact state due to the presence of air remaining between them.

The metal foil winding means 5 is specifically a metal foil winding roller. The metal foil winding roller is pivotally supported by a supporting means (not shown) so as to be rotatable around an axis. Further, the metal foil winding roller is rotationally driven by a driving means (not shown). The metal foil winding roller winds around the circumferential surface of the convex-formed metal foil 2 formed by the processing means 4 while rotating.
According to the metal foil processing apparatus 10, the convex-formed metal foil 2 is manufactured by press-molding the metal foil 8.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.
Example 1
An Nb: YAG laser was mounted as a laser oscillator in a laser processing apparatus (Spectra Physics Co., Ltd.). The intensity of the laser beam output from the processing head was set to 23 μJ per irradiation. Further, the focusing lens and focal length were adjusted, and the imaging magnification of the processing head was set to 16 times. That is, the imaging size of the processing head is 1/16 times the opening of the laser processing mask. As the laser processing mask, a stainless steel plate (SUS304) having a thickness of 0.3 mm and dimensions of 22 mm × 22 mm was subjected to electric discharge machining to form a laser passage hole having a substantially rhombus shape. The diamond-shaped opening diameter of the laser passage hole (the length of the longer diagonal line) was 0.32 mm. The length of the shorter diagonal line was 0.16 mm.

  A forged steel roller (Daido Machinery Co., Ltd., diameter: 50 mm, roller width: 100 mm, Rockwell hardness of forged steel: HRA84.9 on A scale, bending strength : 4.0 GPa, forged steel composition: by weight, carbon 1%, silicon 0.24%, manganese 0.36%, chromium 1.46% and balance iron), and the forged steel roller surface was irradiated for 50 hours. Laser light was irradiated at nanoseconds and an irradiation interval of 1 millisecond. After the laser beam irradiation, the laser beam irradiation region was moved 20 μm in the longitudinal direction of the forged steel roll or 29 μm in the circumferential direction, and the laser beam was irradiated in the same manner. The circumferential movement was performed by rotating a forged steel roller. After moving in the circumferential direction to form 5400 concave portions, moving 20 μm in the longitudinal direction, rotating 14.5 μm in the circumferential direction, and then repeating the operation of forming 5400 concave portions in the circumferential direction. . It was moved 4500 times in the width direction of the roller and processed 90 mm. In this way, 24.3 million recesses were formed in a staggered pattern, and the metal foil processing roller of the present invention was produced.

  The opening shape of the formed recess was approximately rhombus, and the opening diameter (length of the longer diagonal of the rhombus) was 20 μm. The diagonal length of the shorter rhombus was 10 μm. The bottom surface of the recess was dome-shaped, and the depth of the recess was about 12 μm. The pitch in the longitudinal direction of the recess (width direction of the forged steel roll) was about 20 μm, and the pitch in the short side direction (circumferential direction of the forged steel roll) was about 29 μm.

  The two metal foil processing rollers were mounted on the metal foil processing apparatus 10. The pressing force at the pressure nip portion of the metal foil processing apparatus 10 is set to about 14.7 kN · cm (1500 kgf / cm) as a linear pressure, and processing is performed by passing a tough pitch copper foil having a width of 80 mm and a thickness of 26 μm through the pressure nip portion. went. Convex portions corresponding to the concave portions of the metal foil processing roller were formed on the processed copper foil surface. As a result of measuring the average height of 10 convex portions with a laser microscope (trade name: VK-9500, manufactured by Keyence Corporation), it was 7.0 μm. The copper foil was processed at a volume of 100 m / 1 and 20 turns to 2000 m, but the shape of the protrusion formed on the copper foil surface was almost the same, and the height of the protrusion was 7.0 μm. As a result of observing the surface of the metal foil processing roller with a laser microscope, no cracks or chipping occurred.

(Example 2)
Cemented carbide roller (Fuji Dice Co., Ltd., diameter 50 mm, width 100 mm, Rockwell hardness: A scale HRA 90.0, bending strength: 3.1 GPa, tungsten carbide particles and cobalt (binder) The metal foil processing roller of the present invention was produced in the same manner as in Example 1 except that (1) was used.
The two metal foil processing rollers are mounted on the metal foil processing apparatus 10, and the pressure at the pressure nip is changed from about 14.7 kN · cm (1500 kgf / cm) to about 9.8 kN · cm (1000 kgf / cm). Except for this, a tough pitch copper foil having a width of 80 mm and a thickness of 26 μm was processed in the same manner as in Example 1. Convex portions corresponding to the concave portions of the metal foil processing roller were formed on the processed copper foil surface. The average height of 10 convex portions as measured with a laser microscope (VK-9500) was 6.5 μm. The copper foil was processed at a volume of 100 m / 1 and processed 1000 times with 10 rolls. The shape of the protrusions formed on the surface of the copper foil was almost uniform and the height of the protrusions was 6.7 μm. Moreover, as a result of observing the surface of the metal foil processing roller after processing with a laser microscope, generation of cracks and chipping was not observed. Subsequently, a total of 2000 m of copper foil was processed. The shape of the convex part formed on the copper foil surface was almost the same as the initial stage, and the height of the convex part was 6.5 μm. In addition, as a result of observing the surface of the metal foil processing roller with a microscope, a chipping portion where tungsten carbide particles dropped out was observed in part.

(Example 3)
Carbide alloy roller (Fuji Die Co., diameter 50 mm, width 100 mm, Rockwell hardness: A scale HRA89.0, transverse rupture strength: 3.3 GPa, containing tungsten carbide particles and cobalt (binder)) A metal foil processing roller of the present invention was produced in the same manner as in Example 1 except that was used.
The two metal foil processing rollers are mounted on the metal foil processing apparatus 10, and the pressure at the pressure nip is changed from about 14.7 kN · cm (1500 kgf / cm) to about 9.8 kN · cm (1000 kgf / cm). Except for this, a tough pitch copper foil having a width of 80 mm and a thickness of 26 μm was processed in the same manner as in Example 1. Convex portions corresponding to the concave portions of the metal foil processing roller were formed on the surface of the processed copper foil. The average height of 10 convex portions as measured with a laser microscope (VK-9500) was 6.3 μm. Furthermore, when the copper foil was processed into 2000 m with 20 rolls with 100 m / 1 roll, the shape of the protrusions formed on the copper foil surface was almost the same as the initial, and the average height of the 10 protrusions was 6.4 μm. Met. As a result of observing the surface of the metal foil processing roller after processing with a microscope, generation of cracks and chipping was not observed.

Example 4
The metal of the present invention is the same as in Example 1 except that a forged steel roller (Daido Machinery Co., Ltd., diameter 50 mm, width 100 mm, Rockwell hardness: A scale HRA 83.9, bending strength: 5.5 GPa) is used. A foil processing roller was produced. The composition of the forged steel was, by weight, 1.1% carbon, 0.22% silicon, 0.38% manganese, 1.76% chromium and the balance iron.
The two metal foil processing rollers are mounted on the metal foil processing apparatus 10, and the pressure at the pressure nip is changed from about 9.8 kN · cm (1000 kgf / cm) to about 19.6 kN · cm (2000 kgf / cm). Except for this, a tough pitch copper foil having a width of 80 mm and a thickness of 26 μm was processed in the same manner as in Example 1. Convex portions corresponding to the concave portions of the metal foil processing roller were formed on the processed copper foil surface. The average height of 10 convex portions as measured with a laser microscope (VK-9500) was 5.8 μm. Further, when the copper foil was processed at a volume of 100 m / 1 and 20 turns to 2000 m, the shape of the protrusions formed on the surface of the copper foil was almost the same as the initial, and the average height of the 10 protrusions was 5.7 μm Met. As a result of observing the surface of the metal foil processing roller after processing with a microscope, no cracks or chipping occurred.

(Example 5)
The present invention is the same as that of Example 1 except that a die steel roller (Daido Machinery Co., Ltd., diameter 50 mm, roller width 100 mm, Rockwell hardness: H scale 81.2, bending strength: 5.8 GPa) is used. A metal foil processing roller was prepared. The composition of the die steel was carbon 1.4%, silicon 0.4%, manganese 0.6%, chromium 11.2%, molybdenum 0.9%, vanadium 0.3% and the balance iron.
The two metal foil processing rollers were mounted on the metal foil processing apparatus 10, and a tough pitch copper foil having a width of 80 mm and a thickness of 26 μm was processed in the same manner as in Example 4. Convex portions corresponding to the concave portions of the metal foil processing roller were formed on the processed copper foil surface. The average height of 10 convex portions as measured with a laser microscope (VK-9500) was 4.9 μm. Furthermore, when the copper foil was processed to 2000 m with 20 rolls with 100 m / 1 roll, the shape of the protrusions formed on the copper foil surface was almost the same as the initial, and the average height of the 10 protrusions was 5.0 μm. Met. As a result of observing the surface of the metal foil processing roller after processing with a microscope, no cracks or chipping occurred.

(Comparative Example 1)
Cemented carbide roller (Fuji Dice Co., Ltd., diameter 50 mm, width 100 mm, Rockwell hardness: A scale HRA 94.0, bending strength: 1.5 GPa, containing tungsten carbide particles and cobalt (binder)) A metal foil processing roller was produced in the same manner as in Example 1 except that was used. Variations in the opening shape and the opening diameter of the recesses on the peripheral surface of the metal foil processing roller were recognized. In particular, the shape of the opening was almost diamond-shaped, but many were elliptical.

  The two metal foil processing rollers are mounted on the metal foil processing apparatus 10, and the pressure at the pressure nip is changed from about 14.7 kN · cm (1500 kgf / cm) to about 9.8 kN · cm (1000 kgf / cm). Except for this, a tough pitch copper foil having a width of 80 mm and a thickness of 26 μm was processed in the same manner as in Example 1. Convex portions corresponding to the concave portions of the metal foil processing roller were formed on the processed copper foil surface. That is, there was variation in the shape of the convex portion. The average height of 10 convex portions as measured with a laser microscope (VK-9500) was 7.2 μm. Furthermore, when the copper foil was processed at a volume of 100 m / 1 and processed 10 times to 1000 m, a large number of deformed protrusions were observed on the surface of the copper foil. The average height of 10 convex portions was 6.2 μm. As a result of observing the surface of the metal foil processing roller after processing with a microscope, it was observed that the tungsten carbide (WC) particles were chipped off and the recesses were deformed and the roll surface was rough.

(Comparative Example 2)
The metal foil of the present invention was the same as in Example 1 except that a die steel roller (Daido Machinery Co., Ltd., diameter 50 mm, width 100 mm, Rockwell hardness: A scale HRA 78.0, bending strength: 8 GPa) was used. A processing roller was produced. The composition of the die steel was carbon 0.4%, silicon 1.1%, manganese 0.5%, chromium 5.0%, molybdenum 1.0%, vanadium 1.0% and the balance iron. Variations in the opening shape and the opening diameter of the recesses on the peripheral surface of the metal foil processing roller were recognized. In particular, the shape of the opening was almost diamond-shaped, but many were elliptical.

  The two metal foil processing rollers are mounted on the metal foil processing apparatus 10, and the pressure at the pressure nip is about 9.8 kN · cm (1000 kgf / cm), about 14.7 kN · cm (1500 kgf / cm), or about 19 A tough pitch copper foil having a width of 80 mm and a thickness of 26 μm was processed in the same manner as in Example 1 except that it was set to 0.6 kN · cm (2000 kgf / cm). Convex portions corresponding to the concave portions of the metal foil processing roller were formed on the processed copper foil surface. That is, there was variation in the shape of the convex portion. The average height of the ten convex portions measured by a laser microscope (VK-9500) is 2.2 μm (about 9.8 kN · cm), 2.3 μm (about 14.7 kN · cm), 2.3 μm (about 19.6 kN · cm). It has been found that the height of the convex portion does not increase even when the pressure at the pressure nip is increased. This is considered to be because the metal foil processing roller becomes flatter as the pressure is increased, the area where the roller surface and the copper foil are in contact with each other increases, and the actual load applied to the copper foil does not increase.

From the results of Examples 1 to 5 and Comparative Examples 1 and 2, when using the metal foil processing roller of the present invention, a convex portion having a height of 4 μm or more and a substantially uniform shape with respect to a copper foil of 1000 m or more, It is clear that it can be stably formed in units of tens of millions. The metal foil machining roller of the present invention, which Rockwell hardness of HRA81.2~90.0 in A scale and transverse rupture strength is concave roller is made of a metal material is 3GPa~6GPa formed It is.
Further, when a metal foil processing roller made of a metal material having a Rockwell hardness of A scale and HRA of 81.2 or less or a bending strength of 3 GPa or less is used, even if the roller is flattened and the pressure at the press nip is increased, It is clear that a convex part having a height of 3 μm or more cannot be formed on the copper foil. Furthermore, when a metal foil processing roller containing a metal material having a Rockwell hardness of A scale of HRA 90.0 or higher or a bending strength of 6 GPa or higher is used, chipping occurs, the concave portion is deformed, and the roller surface becomes rough. It was found that stable processing was not possible.

  The metal foil processing roller of the present invention can be suitably used for forming convex portions on the surfaces of various metal foils. In particular, since the metal foil processing roller of the present invention exhibits high durability, even when mass-producing metal foil having convex portions, it can be produced efficiently and at a very low defective product rate, which is industrially advantageous. .

It is a side view which shows typically the structure of a convex part formation metal foil processing apparatus. It is a perspective view which expands and shows the structure of the principal part of the convex part formation metal foil processing apparatus shown in FIG. It is drawing which shows the structure of the roller for metal foil processing. Fig.3 (a) is a perspective view which shows the external appearance of the roller for metal foil processing. FIG. 3B is an enlarged perspective view showing the surface area of the metal foil processing roller shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal foil processing roller 1a Concave part 2 Convex part formation metal foil 3 Metal foil supply means 4 Processing means 5 Metal foil winding means 6 Pressure nip part 7 Line unit 8 Metal foil 9 Convex part 10 Metal foil processing apparatus

Claims (8)

A plurality of recesses are formed on the circumferential surface by laser processing to form a height 4μm or more protrusions of the plurality of columnar to the metal foil surface is pressed against the peripheral surface to the metal foil is a copper foil or copper alloy foil Te, a negative electrode current collector processing rollers in order to obtain a negative electrode current collector for a lithium secondary battery,
Surface portion at least the recess is formed, Rockwell hardness of HRA81.2~90.0 in A scale and transverse rupture strength is Ri Do a metallic material is 3GPa～6GPa,
The cross-sectional shape of the recess in a direction perpendicular to the peripheral surface, wherein the circumferential surface toward the bottom surface of the recess, the negative electrode current collector processing rollers sectional width Ru gradually or successively smaller tapered der . 2. The negative electrode current collector processing roller according to claim 1, wherein an opening shape of the concave portion is a substantially circular shape, a substantially oval shape, a substantially rhombus shape, or a substantially regular polygon shape. Anode current collector processing rollers according to claim 1 or 2 opening diameter is 1μm~35μm of the recess. Anode current collector processing rollers according to any one of claims 1 to three pitches is 4μm or more of the recesses in the axial direction of the metal foil machining roller in the circumferential surface. The Rockwell hardness of the metallic material is HRA83.9~89.0 in A scale according to any one of claims 1-4 transverse rupture strength is 3.3GPa~5.5GPa of the metallic material Negative electrode current collector processing roller. The metallic material is cemented carbide, cermet, high-speed steel, a negative electrode current collector according to any one of claims 1 to 5, at least one high melting point metal material selected from die steel and the group consisting of forged steel Processing roller. The negative electrode current collector processing roller according to any one of claims 1 to 6 , wherein the roller is used so that the bottom surface of the recess does not contact the surface of the metal foil. At least one is a copper foil or a copper alloy foil in a pressure nip formed by pressure- contacting a pair of rollers made of a negative electrode current collector processing roller having a plurality of concave portions formed by laser processing on the peripheral surface A negative electrode current collector processing method of supplying a metal foil, forming a columnar convex portion having a height of 4 μm or more on the surface of the metal foil, and obtaining a negative electrode current collector for a lithium secondary battery ,
The surface layer portion where at least the concave portion of the negative electrode current collector processing roller is formed is made of a metal material having a Rockwell hardness of A scale of HRA 81.2 to 90.0 and a bending strength of 3 GPa to 6 GPa. Do Ri,
Cross-sectional shape of the recess in a direction perpendicular to the peripheral surface, towards the said peripheral surface to the bottom surface of the recess, cross-sectional width, characterized in gradually or successively smaller tapered der Rukoto anode current Electrical processing method.

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