Titanium plate, titanium ring, and copper foil production drum

Abstract

This titanium plate or titanium ring has a chemical composition which includes, in mass%, 0.010-0.045% Fe, 0.010-0.150% O, 0-1.00% Cu, 0-2.00% Al, 0-2.00% Sn, 0-2.00% Zr, 0-0.080% C, 0-0.050% N, and 0-0.015% H, with the remainder comprising Ti and impurities. In said titanium plate or titanium ring, the crystal grain boundary length per unit area is 50 mm-1 or less, and the standard deviation of a Gaussian function is 15° or less, said standard deviation being obtained by fitting, to the Gaussian function, a graph indicating each area ratio of the crystal grains per 5° increment of the angle formed by the plate thickness direction and the c-axis of the hexagonal close-packed structure.

Description

Titanium plate, titanium ring, and copper foil manufacturing drums 【0001】 This invention relates to titanium plates, titanium rings, and copper foil manufacturing drums. This application claims priority under Japanese Patent Application No. 2024-217646, filed in Japan on December 12, 2024, the contents of which are incorporated herein by reference. 【0002】 Copper foil is often used as a raw material for the wiring in circuit boards such as multilayer circuit boards and flexible circuit boards, as well as for the conductive parts of electronic components such as current collectors in lithium-ion batteries. 【0003】 Copper foil used for such applications is manufactured by a copper foil manufacturing apparatus equipped with a copper foil manufacturing drum. Figure 5 is a schematic diagram of the copper foil manufacturing apparatus. The copper foil manufacturing apparatus 1, for example as shown in Figure 5, comprises an electrolytic cell 10 in which a copper sulfate solution is stored, an electrodeposition drum 2 provided in the electrolytic cell 10 so as to be partially immersed in the copper sulfate solution, and an electrode plate 30 provided in the electrolytic cell 10 so as to be immersed in the copper sulfate solution and facing the outer surface of the electrodeposition drum 2 at a predetermined distance. By applying a voltage between the electrodeposition drum 2 and the electrode plate 30, copper foil A is generated on the outer surface of the electrodeposition drum 2 by electrodeposition. The copper foil A, which has reached a predetermined thickness, is peeled off the electrodeposition drum 2 by a winding unit 40 and wound onto a winding roll 60 while being guided by a guide roll 50. 【0004】 Titanium is commonly used for the surface (outer surface) of drums (electroplated drums) due to its excellent corrosion resistance and ease of copper foil release. However, even when using corrosion-resistant titanium, if copper foil is manufactured over a long period, the surface of the titanium material constituting the drum surface will gradually corrode in the copper sulfate solution. The state of the corroded drum surface can then be transferred to the copper foil during the manufacturing process. 【0005】It is known that the state and extent of corrosion of metallic materials vary depending on various internal factors resulting from the metallic structure, such as the crystalline structure, crystal orientation, defects, segregation, processing strain, and residual strain. When a drum made of a metallic material with heterogeneous metallic structure between parts is corroded during the manufacture of copper foil, the homogeneous surface condition of the drum is not maintained, and heterogeneous surfaces appear on the drum surface. Therefore, titanium material with a high-precision surface is required for the manufacture of copper foil of uniform thickness. 【0006】 As a technology aimed at meeting the demand for the manufacture of copper foil with high precision and uniform thickness, Patent Document 1 discloses a titanium plate having a texture that is uniform and fine in structure, and that can suppress macro patterns and patterns that occur on the drum surface during copper foil manufacturing. Specifically, Patent Document 1 discloses a titanium plate made of industrial pure titanium or a Cu-added alloy, wherein the average grain size is 40 μm or less, and when the normal to the (0001) plane is taken as the c axis, the area ratio of all grains where the c axis is tilted at an angle of 40° or less from the normal direction of the plate surface is 70% or more and the standard deviation is 0.80 or less. 【0007】 Furthermore, Patent Document 2 discloses a titanium plate having a chemical composition comprising, by mass%, one or more elements from the group consisting of Sn: 0% to 2.0%, Zr: 0% to 5.0%, and Al: 0% to 7.0%: totaling 0.2% to 7.0%, N: 0.100% or less, C: 0.080% or less, H: 0.015% or less, O: 0.700% or less, and Fe: 0.500% or less, with the remainder being Ti and impurities; an average crystal grain size of 40 μm or less; a standard deviation of the grain size distribution based on the logarithm of the crystal grain size per unit μm of 0.80 or less; an α phase having a hexagonal close-packed crystal structure; and an area ratio of crystal grains of 70% or more in which the angle of the α phase in the

[0001] direction with respect to the plate thickness direction is 0° or more and 40° or less. 【0008】Furthermore, Patent Document 3 discloses a titanium plate that is an industrial pure titanium or Cu-added alloy, wherein the average grain size is 40 μm or less, the standard deviation of the grain size distribution based on the logarithm of the grain size (μm) is 0.80 or less, and when the crystal orientation is expressed in Euler angles according to Bunge's notation, the area ratio of crystal grains having a crystal orientation with an orientation difference of 15° or less, centered on the orientation where the degree of accumulation is maximum, is 20% or more. 【0009】 International Publication No. 2020 / 213715, International Publication No. 2020 / 213719, International Publication No. 2020 / 213713 【0010】 Incidentally, with the miniaturization and increased density of electronic components, there is a demand for even thinner copper foil, and as the thickness of the copper foil increases, a high-precision surface condition is required. 【0011】 This invention has been made in view of the above problems, and aims to provide a titanium plate, a titanium ring, and a copper foil manufacturing drum having a metallic structure suitable for manufacturing copper foil with excellent smoothness. 【0012】 The inventors have obtained the following findings: One of the factors influencing the smoothness of the copper foil being manufactured is the nucleation of Cu crystal grains on the titanium surface in the early stages of copper foil manufacturing. The more uniformly these nuclei are formed, the more uniform the subsequent grain growth becomes. As a result, it has been found that it becomes easier to manufacture copper foil with superior smoothness. The inventors conducted further studies and have invented a titanium plate, a titanium ring, and a copper foil manufacturing drum that exhibit superior uniform nucleation during copper foil manufacturing compared to conventional materials. 【0013】 Based on the above findings, the gist of the present invention is as follows: [1] A titanium plate according to one aspect of the present invention has a chemical composition consisting of, by mass%, Fe: 0.010 to 0.045%, O: 0.010 to 0.150%, Cu: 0 to 1.00%, Al: 0 to 2.00%, Sn: 0 to 2.00%, Zr: 0 to 2.00%, C: 0 to 0.080%, N: 0 to 0.050%, and H: 0 to 0.015%, with the remainder being Ti and impurities, and has a grain boundary length of 50 mm per unit area. －１The following is the case, characterized in that the standard deviation of the Gaussian function obtained by fitting a graph showing the area ratio of crystal grains at 5° intervals, where the angle between the plate thickness direction and the c-axis of the hexagonal close-packed structure is 15° or less, to a Gaussian function. [2] The titanium plate described in [1] above may have a peak position of crystal grain accumulation within 30° from the normal direction of the plate surface when the peak position of crystal grain accumulation is displayed using a (0001) pole figure from the thickness direction. [3] The titanium plate described in [1] or [2] above may have a thickness of 4.0 to 20.0 mm. 【0014】 [4] A titanium ring according to another aspect of the present invention has a chemical composition in mass%, containing Fe: 0.010 to 0.045%, O: 0.010 to 0.150%, Cu: 0 to 1.00%, Al: 0 to 2.00%, Sn: 0 to 2.00%, Zr: 0 to 2.00%, C: 0 to 0.080%, N: 0 to 0.050%, and H: 0 to 0.015%, with the remainder being Ti and impurities, and has a grain boundary length of 50 mm per unit area. －１ The titanium ring is characterized in that the standard deviation of the Gaussian function obtained by fitting a graph showing the area ratio of crystal grains at 5° intervals, where the angle between the plate thickness direction and the c-axis of the hexagonal close-packed structure is 15° or less, to a Gaussian function. [5] The titanium ring described in [4] above may have a peak position of crystal grain accumulation within 30° from the normal direction of the plate surface of the titanium plate when the peak position of crystal grain accumulation is displayed using the (0001) pole from the thickness direction. [6] The titanium ring described in [1] or [2] above may have a thickness of 4.0 to 20.0 mm. 【0015】 [7] A copper foil manufacturing drum according to another aspect of the present invention comprises a cylindrical inner drum and either a titanium plate according to any one of [1] to [3] or a titanium ring according to any one of [4] to [6] attached to the outer surface of the inner drum. 【0016】 According to the present invention, copper foil with excellent smoothness can be manufactured. 【0017】This figure shows crystal grains having a hexagonal close-packed structure. This is an explanatory diagram for explaining the crystal orientation of the α phase. This is an example of a graph showing the area ratio of crystal grains for each angle between the thickness direction (ND) and the c-axis of hcp. This is a schematic diagram of a copper foil manufacturing drum according to one embodiment of the present invention. This is a schematic diagram showing the general configuration of a copper foil manufacturing apparatus. 【0018】 Preferred embodiments of the present invention will be described in detail below with reference to the drawings. The numerical limits described below include both lower and upper limits. Numbers indicated as "greater than" or "less than" are not included in the numerical range. Furthermore, "%" in relation to chemical composition means "mass percent" unless otherwise specified. 【0019】 <Titanium Plate> The titanium plate according to one embodiment of the present invention has a chemical composition consisting of, by mass%, Cu: 0-1.00%, Al: 0-2.00%, Sn: 0-2.00%, Zr: 0-2.00%, C: 0-0.080%, N: 0-0.050%, and H: 0-0.015%, with the remainder being Ti and impurities, and has a grain boundary length of 50 mm per unit area. －１ The following conditions apply: The standard deviation of the Gaussian function obtained by fitting a graph showing the area ratio of crystal grains at 5° intervals between the angle between the plate thickness direction and the c-axis of the hexagonal close-packed structure to a Gaussian function is 15° or less. The Gaussian function referred to here is the probability density function of the normal distribution, and is expressed by the following equation (1) when the mean is μ and the standard deviation is σ. In equation (1), A is a constant. In this disclosure, the standard deviation refers to the standard deviation σ of the Gaussian function. The fitting of the graph showing the area ratio of crystal grains at 5° intervals between the angle between the plate thickness direction and the c-axis of the hexagonal close-packed structure to a Gaussian function is performed by the least squares method. Hereinafter, the standard deviation of the Gaussian function obtained by fitting a graph showing the area ratio of crystal grains at 5° intervals between the angle between the plate thickness direction and the c-axis of the hexagonal close-packed structure to a Gaussian function may be simply referred to as the standard deviation of the Gaussian function. 【0020】 【0021】(Chemical Composition) The titanium plate according to this embodiment is either a plate of industrial-grade pure titanium or a plate of a titanium alloy having a metallic structure with the α phase as the main phase. Copper foil is manufactured in a corrosive environment, as described above. Therefore, depending on the titanium plate, its surface may become rough due to corrosion, and variations may occur in the smoothness of the copper foil electrodeposited on the rough surface of the titanium plate. Since the β phase is more susceptible to corrosion than the α phase, it is desirable to have a smaller proportion of the β phase in the metallic structure of the titanium plate. In addition, it is important to have a relatively large grain size of the titanium plate in order to uniformly form Cu crystal nuclei during copper foil manufacturing. If the proportion of the β phase is large, it becomes difficult to enlarge the crystal grains due to the pinning effect. Therefore, it is desirable to have a small proportion of the β phase and a large proportion of the α phase. In order to have the α phase as the main phase, the composition and range of the titanium plate are as follows. 【0022】 Fe: 0.010-0.045% Fe (iron) is a β-stabilizing element and is included in industrial pure titanium for solid solution strengthening. Since solid solution strengthening improves the polishability of the titanium plate, the Fe content is 0.010% or more. Preferably, the Fe content is 0.012% or more, or 0.015% or more. On the other hand, if the Fe content is too high, the proportion of the β phase becomes too large, and grain growth is suppressed. Therefore, in this embodiment, the Fe content is 0.045% or less. Preferably, the Fe content is 0.043% or less, or 0.040% or less. 【0023】 O: 0.010-0.150% Oxygen (O) is an α-stabilizing element that improves the strength of the α-phase, thereby improving the strength of industrial pure titanium sheets and titanium alloy sheets. When the strength of the titanium sheet is improved to a certain extent, the polishability improves. Therefore, the O content is 0.010% or more. Preferably, the O content is 0.015% or more. On the other hand, if the O content is excessive, the titanium sheet becomes too hard, making it difficult to process into a drum. Therefore, the O content is 0.150% or less. Preferably, the O content is 0.120% or less, or 0.100% or less. 【0024】Cu: 0-1.00% Like Fe, Cu (copper) is a β-stabilizing element. Furthermore, Cu has a relatively large solid solubility limit in the α phase compared to other β-stabilizing elements, so even if a large amount of Cu is present, the β phase is less likely to precipitate compared to Fe. Also, Cu hardens titanium plates, so when titanium plates contain Cu, the load when processing the titanium plates into drums increases, but it also makes it easier to polish the titanium plates uniformly during polishing. However, if the Cu content exceeds 1.00%, the Cu will not fully dissolve and Ti ２ Cu and β phases precipitate, suppressing grain growth. Therefore, the Cu content is 1.00% or less. On the other hand, the Cu content is preferably 0.80% or less. Cu may not be present, and the Cu content may be 0%. The Cu content is preferably 0.20% or more. 【0025】 Al: 0-2.00% Aluminum (Al) is an α-stabilizing element. Al also has high solid solution strengthening ability and can harden the α phase. On the other hand, if the Al content is too high, grain growth is suppressed. Therefore, the Al content is preferably 2.00% or less, 1.50% or less, or 1.20% or less. On the other hand, Al may not be included, and the Al content may be 0%. Furthermore, in order to obtain solid solution strengthening ability, the Al content is preferably 0.20% or more, or 0.50% or more. 【0026】 Sn: 0-2.00% Although tin (Sn) is a neutral element, it can harden the α phase through solid solution strengthening, similar to Al. Therefore, the Sn content is preferably 2.00% or less, 1.50% or less, or 1.20% or less. On the other hand, Sn may not be present, and the Sn content may be 0%. Furthermore, in order to obtain solid solution strengthening ability, the Sn content is preferably 0.20% or more, or 0.50% or more. 【0027】Zr: 0-2.00% Zr (zirconium), like Sn, is a neutral element, but it can harden the α phase through solid solution strengthening. Therefore, the Zr content is preferably 2.00% or less, 1.50% or less, or 1.20% or less. On the other hand, Zr may not be present, and the Zr content may be 0%. Furthermore, in order to obtain solid solution strengthening ability, the Zr content is preferably 0.20% or more, or 0.50% or more. 【0028】 C: 0-0.080% Carbon (C) has a similar effect to oxygen (O), but the strength and other properties are basically controlled by adjusting the O content. Also, C forms carbides with Ti, and these carbides may embrittle the titanium plate. For this reason, a low C content is preferable, preferably 0.080% or less, or 0.050% or less. C may not be present, and the C content may be 0%. However, C is an impurity introduced from the raw material sponge titanium, scrap, or alloying element raw materials, and the actual C content is 0.0001% or more, preferably 0.005% or more. 【0029】 N: 0-0.050% Nitrogen (N) has a similar effect to oxygen (O), but the O content is basically adjusted to control the strength of the titanium plate. Also, N, like O, has a large solid solution strengthening effect, and if the O content is too high, the titanium plate will become too hard. For this reason, a low N content is preferable, preferably 0.050% or less, or 0.030% or less. N may not be present, and the N content may be 0%. However, N is an impurity introduced from the raw material sponge titanium, scrap, or alloying element raw material, and the actual N content is 0.0001% or more, preferably 0.005% or more. 【0030】H: 0 to 0.015% H (hydrogen) is an impurity. If the H content is too high, hydrides are formed, and the titanium plate becomes brittle due to these hydrides. In the present embodiment, since embrittlement is suppressed if the H content is 0.015% or less, the H content is preferably 0.015% or less. The H content is more preferably 0.010% or less. H may not be contained, and the H content may be 0%. However, since H is absorbed during the manufacturing process of the titanium plate, the substantial H content is 0.001% or more. 【0031】 The titanium plate according to the present embodiment may contain all elements other than the above-described elements. The content of each element other than the above-described elements is, for example, 0.2% or less, and the total content is 1.0% or less. 【0032】 The remainder of the chemical composition of the titanium plate according to the present embodiment is Ti and impurities. Specific examples of the impurities other than the above-described elements are Cl, Na, Mg, Si, Ca mixed in the refining process, and Mo, Nb, Ta, V, Cr, Mn, Co, Ni, Cu, etc. mixed from scrap. The content of each impurity element is, for example, 0.2% or less, and the total content is, for example, 1.0% or less. 【0033】 The content of each of the above elements is quantified by ICP emission spectrometry. However, for the quantification of O and N, an oxygen / nitrogen simultaneous analyzer is used, and O and N are quantified by inert gas fusion, thermal conductivity / infrared absorption method. For the quantification of C, a carbon / sulfur simultaneous analyzer is used, and C is quantified by infrared absorption method. H is quantified by inert gas fusion, infrared absorption method. 【0034】 (Metallographic structure) In the titanium plate according to the present embodiment, the grain boundary length per unit area (1 mm ２ ) is 50 mm －１The following is the case. When there is a part on the drum surface where the electrical resistance is extremely smaller than the surroundings during copper electroplating, the inventors have found that this part becomes a preferential nucleation site for Cu crystal grains, and local nucleation occurs. In metal materials, grain boundaries are parts where the electrical resistance is smaller than other parts outside the grain boundaries. That is, in the electroplating of Cu, when there is a part on the titanium material of the drum surface where the density of grain boundaries is higher than the surroundings, nuclei of Cu concentrate and form in that part. Thus, the inventors have found that the density of nuclei of Cu crystal grains becomes non-uniform. Therefore, it is better that the number of grain boundaries in the titanium plate is smaller. When the grain boundary length per unit area is 50 mm －１ or less, the density of grain boundaries appearing on the surface of the drum becomes sufficiently small, and uniform nucleation of Cu becomes possible. The grain boundary length per unit area is preferably 40 mm －１ or less, and more preferably 35 mm －１ or less. Since the shorter the grain boundary length per unit area is better, the lower limit is not particularly limited. The grain boundary length per unit area may be, for example, 1 mm －１ or more. 【0035】 Incidentally, between the grain boundary area S per unit volume Ｖ and the average section length L, as described in Nobuyasu Tsujinobu, "Ultra-Fine Grain Refinement of Steel Materials", Iron and Steel, Vol. 88 (2002), No. 7, pp358-369, there is a relationship of S Ｖ = 2 / L. The average section length L is the average line segment length per grain of the test line cutting across the inside of the grain in JIS G 0551:2020 Steel - Microscopic Test Method for Crystal Grain Size. The grain boundary area S per unit volume Ｖ is equal to the grain boundary area per unit area when considering a cross-section of the titanium plate. Also, the average section length L can be read as the average crystal grain size. According to this relationship, when the grain boundary length per unit area is 50 mm －１ or less, the average crystal grain size is more than 40 μm. The average crystal grain size of the titanium plate according to this embodiment may be 50 μm or more, or may be more than 65 μm. When the average crystal grain size is 50 μm or more, the grain boundary length per unit area is 40 mm －１The following applies: When the average grain size is greater than 65 μm, the grain boundary length per unit area is 31 mm. －１ The following applies, and the crystal grains of the titanium plate according to this embodiment are recrystallized grains, and the aspect ratio of the crystal grains is 2.0 or less. 【0036】The grain boundary length per unit area is measured by electron backscatter diffraction (EBSD). The target area for analysis to measure the grain boundary length per unit area is as follows: The target area is a 2 mm × 2 mm region on the cross-section (cut surface) obtained by cutting with a plane that includes the thickness direction of the plate. The cutting position to obtain the cut surface is any position on the plate surface where the cutting line where the cut surface and the plate surface (RD-TD plane) intersect is 30 mm or more away from the edge of the plate surface, or it includes the centroid of the titanium plate. The cut surface only needs to include the thickness direction of the plate. Furthermore, the 2 mm × 2 mm target area is taken from the portion of the cut surface that is at least 1 mm inward from the edge in the thickness direction and at least 3 mm inward from the edge in the direction perpendicular to the thickness direction of the plate. The analysis area for measuring the average grain size and the standard deviation of the Gaussian function is the same as described above. The titanium plate can be any plate from which the aforementioned cross-section can be taken. Within the above-mentioned target area, if the chemical composition, grain boundary length, and standard deviation are satisfied, copper foil can be manufactured by electrodeposition. However, for the efficient production of copper foil with superior smoothness, a large, uniform plate shape that satisfies the aforementioned chemical composition, grain boundary length, and standard deviation of the Gaussian function over a larger area is desirable. Furthermore, the shape of an endless ring including the aforementioned drum is most desirable. However, in the case of a ring manufactured by welding at the ends, the welded area is likely to have a different metal structure. Therefore, the welded area is excluded from the measurement area by EBSD. In this case, although manufacturing efficiency decreases, the exclusion of the electrodeposited portion at the welded area of ​​the copper foil makes it possible to manufacture copper foil with superior smoothness. The most preferred example is a ring manufactured by ring rolling. Such a ring has no welded areas, enabling continuous production of copper foil. If a weld is present, the sample obtained by unfolding the ring after cutting at the weld is used as the sample for EBSD measurement. If there is no weld, the sample obtained by unfolding the ring after cutting at an arbitrary point, or a sample of a part of the ring, is used as the sample for EBSD measurement. Alternatively, the sample obtained by unfolding the ring after cutting at a weld, or the sample obtained by unfolding the ring after cutting at an arbitrary point, is used as the sample for EBSD measurement.The shape of the sample obtained by unfolding a ring after cutting it at a weld, the sample obtained by unfolding a ring after cutting it at an arbitrary point, and the sample assumed to be obtained by unfolding a ring after cutting it at a weld, and the sample assumed to be obtained by unfolding a ring after cutting it at an arbitrary point, is plate-like. If the weld cannot be identified, similar EBSD measurements can be performed on the area where the copper foil is electrodeposited. 【0037】 The grain boundary length per unit area is measured by the following method: A cross-section of a titanium plate cut along a plane including the thickness direction is chemically polished, and 10 fields of view measurements are taken in a 2 mm × 2 mm area at 2 μm steps using EBSD. Boundaries where the crystal orientation difference between adjacent phases measured by EBSD is 5° or more are defined as grain boundaries. The total length of grain boundaries detected in each field of view is divided by the area of ​​that field of view, and the average value is taken as the grain boundary length per unit area. The total length of grain boundaries detected in each field of view is determined by analyzing the boundaries where the crystal orientation difference between adjacent phases is 5° or more using TSL Solutions' OIM Analysis (Ver. 8.1.0) software, defining them as grain boundaries. 【0038】 The average grain size is calculated using the following method: Similar to the measurement of grain boundary length per unit area, the cross-section (cut surface) obtained by cutting along a plane including the thickness direction of the plate is chemically polished, and 10 fields of view are measured in a 2 mm × 2 mm area using EBSD in 2 μm steps. From the grain area measured by EBSD, the equivalent circle (area A = π × (grain size D / 2)) is calculated. ２ The average grain size is determined, and the average of the average grain sizes measured in 10 fields of view is taken as the average crystal grain size. 【0039】The crystalline phase of titanium varies depending on its chemical composition. Figure 1 shows a crystal grain having a hexagonal close-packed structure. The α-phase crystal structure takes the form of a hexagonal close-packed (hcp) structure as shown in Figure 1. In the titanium plate according to this embodiment, the standard deviation obtained by fitting a graph showing the area ratio of crystal grains at 5° intervals between the angle between the plate thickness direction and the c-axis of the hexagonal close-packed structure to a Gaussian function is 15° or less. The electrical resistance of the titanium plate is greatly affected by the crystal orientation. Figure 2 is an explanatory diagram for explaining the crystal orientation of the α-phase. As schematically shown in Figure 2, the c-axis of the α-phase may be tilted by an angle θ with respect to the plate thickness direction. The angle θ is determined by the angle between the plate thickness direction and the c-axis. The electrical resistance differs depending on the tilt of the c-axis of the α-phase with respect to the plate thickness direction. During copper foil manufacturing, the growth rate of copper changes depending on the ease with which current flows in the titanium plate. Therefore, a smaller variation in the crystal orientation of the crystal grains in the titanium plate makes it possible to uniformly electrodeposit the copper foil. Consequently, a smaller variation in the crystal orientation of the titanium plate is desirable, and especially in copper electrodeposition, since current is passed in the thickness direction of the plate, a smaller variation in the crystal orientation difference with respect to the thickness direction is desirable. In this embodiment, the standard deviation obtained by fitting a graph showing the area ratio of crystal grains at 5° intervals between the angle between the thickness direction and the c-axis of the hexagonal close-packed structure to a Gaussian function is 15° or less. Figure 3 is an example of a graph showing the area ratio for each division when the crystal grains are divided according to the angle between the thickness direction (ND) and the c-axis of hcp. The horizontal axis of Figure 3 shows the orientation difference between the thickness direction (ND) of the titanium plate and the c-axis of the α phase, and the vertical axis shows the area ratio of the α phase having said orientation difference. In Figure 3, the area of ​​the total area within the range of θ from 5 × N degrees to 5 × (N + 1) degrees (where N is an integer from 0 to 17) is plotted as an area ratio of (5N + 5 / 2). The titanium material in this embodiment has a Gaussian function whose standard deviation is 15° or less, obtained by fitting a graph showing the area ratio of crystal grains at 5° intervals between the angle between the plate thickness direction and the c-axis of the hexagonal close-packed structure, as shown in Figure 3, to a Gaussian function. 【0040】To calculate the standard deviation of the Gaussian function, the EBSD analysis target area is defined as a region of 50 μm thickness × width in the cross-section (cut surface) obtained by cutting with a plane including the thickness direction. Within this target area, the crystal grains are divided according to the angle between the c-axis of hcp obtained by EBSD and the thickness direction, and the area fraction graph for each division is fitted to the Gaussian function. In the measurement area of ​​50 μm thickness × width in the measurement cross-section of the titanium plate obtained as described above, the crystal orientation difference of adjacent phases is measured by EBSD in 2 μm steps for approximately 10 fields of view. From the obtained data, an area fraction graph is created using OIM Analysis software (Ver. 8.1.0) from TSL Solutions. Specifically, the width of the angle between the c-axis of hcp and the thickness direction (bin width) is set to 5°, and area fraction data for each angular range is extracted. If the standard deviation when fitting it to a Gaussian function using the least squares method is 15° or less, then the variation in the c-axis direction relative to the plate thickness direction will be small, enabling the production of uniform copper foil. 【0041】 The thickness of the titanium plate according to this embodiment is not particularly limited and is set appropriately according to the application and specifications of the drum being manufactured. When a titanium plate is used as the material for a copper foil manufacturing drum, the thickness of the titanium plate decreases with use of the copper foil manufacturing drum. For this reason, the thickness of the titanium plate is preferably 4.0 mm or more, and may be 6.0 mm or more. The upper limit of the thickness of the titanium plate is not particularly limited. For example, the thickness of the titanium plate is 20.0 mm or less. The thickness of the titanium plate is preferably 18.0 mm or less, and more preferably 15.0 mm or less. 【0042】 According to the embodiments described above, the chemical composition of the titanium plate is within the range mentioned above, and the grain boundary length per unit area is 50 mm. －１ The following conditions are met: The standard deviation of the Gaussian function obtained by fitting a graph showing the area ratio of crystal grains at 5° intervals between the angle between the thickness direction and the c-axis of the hexagonal close-packed structure to a Gaussian function is 15° or less. Therefore, the nuclei of Cu crystal grains can be formed uniformly during copper foil manufacturing. As a result, copper foil with excellent smoothness can be manufactured. 【0043】(Peak position of grain density) When the peak position of grain density is displayed using the (0001) pole figure from the thickness direction (ND) of the titanium plate, it is preferable that the peak position of grain density is within 30° from the normal direction (thickness direction) of the surface of the titanium plate. Here, the density is calculated by texture analysis using the spherical harmonic function method of backscattered electron diffraction (EBSD) for the inverse pole figure, where the development index is 16 and the Gaussian full width at half maximum is 5°. The peak position of grain density is shown in the (0001) pole figure from the thickness direction (ND) with the orientation of greatest density. Since the electrical resistance is small in the c-axis direction, by making the c-axis direction the direction of the peak position of grain density, the electrical resistance in the thickness direction is reduced, making it easier for current to flow in the thickness direction during copper electrodeposition, and allowing the copper foil to be electrodeposited uniformly. Similar to titanium plates, when displaying the peak position of the grain density using a (0001) pole figure from the thickness direction (ND) of the titanium ring, it is preferable that the peak position of the grain density is within 30° from the normal direction (thickness direction) of the surface of the titanium ring. 【0044】 <Copper Foil Manufacturing Drum> Figure 4 is a schematic diagram of a copper foil manufacturing drum according to one embodiment of the present invention. Figure 5 is a schematic diagram showing the general configuration of a copper foil manufacturing apparatus. As shown in Figure 4, the electrodeposition drum 20 according to this embodiment is used by being incorporated into a copper foil manufacturing apparatus as shown in Figure 5. The electrodeposition drum 20 in Figure 4 has a cylindrical inner drum 21 and a titanium ring 22 attached to the outer circumferential surface of the inner drum 21. The titanium ring 22 is manufactured by deforming a titanium plate according to the above embodiment into a ring shape, and then welding both ends or by ring rolling. The titanium ring 22 is a titanium ring according to an embodiment of the present invention. Therefore, the titanium ring 22 has a chemical composition consisting of, by mass%, Fe: 0.010-0.045%, O: 0.010-0.150%, Cu: 0-1.00%, Al: 0-2.00%, Sn: 0-2.00%, Zr: 0-2.00%, C: 0-0.080%, N: 0-0.050%, and H: 0-0.015%, with the remainder being Ti and impurities, and has a grain boundary length of 50 mm per unit area. －１The following conditions apply: The standard deviation of the Gaussian function obtained by fitting a graph showing the area ratio of crystal grains at 5° intervals, where the angle between the plate thickness direction and the c-axis of the hexagonal close-packed structure is 15° or less, to the Gaussian function. 【0045】 The size of the copper foil manufacturing drum according to this embodiment is not particularly limited, but the diameter of the drum is, for example, 1 to 5 m. 【0046】 The inner drum 21 may be of known origin, and its material does not have to be titanium; for example, it may be mild steel or stainless steel. A titanium plate is wrapped around the outer circumference of a cylindrical inner drum 21 and the butt joint is welded to form a titanium ring 22, which is then fitted onto the inner drum. Alternatively, a titanium ring 22 manufactured by ring rolling is shrink-fitted onto the inner drum 21. 【0047】 The electrodeposition drum 20 according to this embodiment is an electrodeposition drum manufactured using the titanium plate or titanium ring according to this embodiment. In the electrodeposition drum 20 according to this embodiment, the titanium plate or titanium ring according to this embodiment is used on the surface of the drum on which the copper foil is electrodeposited, so that copper foil with excellent smoothness can be manufactured. 【0048】 <Manufacturing Method for Titanium Plates> The titanium plates according to the embodiments described above may be manufactured by any method, but for example, they may be manufactured by the manufacturing method for titanium plates according to the embodiments described below. 【0049】 A preferred method for manufacturing the titanium sheet according to this embodiment is a known method, for example, the method disclosed in International Publication No. 2020 / 213715, in which a titanium material having the above-mentioned components is hot-rolled. However, in this embodiment, rolling is performed in a temperature range of 200 to 650°C, and the maximum reduction ratio per pass in the rolling is 35% or less. Subsequently, the titanium sheet after hot-rolling is heat-treated under the following conditions: Temperature (T): 600°C or higher, below the β transformation point Time (t): 20 minutes or more, 480 minutes or less LMP = (Log １０ (t × 60) + 20) × (T + 273.15) ≥ 23000 …(Equation (2)) (Log １０(t × 60) + 20) × (T + 273.15) is the Larson-Miller parameter (LMP), where t is the heat treatment time (minutes) and T is the heat treatment temperature (°C). 【0050】 If the maximum reduction ratio per pass during rolling in the temperature range of 200 to 650°C is 35% or less, the standard deviation of the Gaussian function obtained by fitting a graph showing the area ratio of crystal grains at 5° intervals between the angle between the thickness direction and the c-axis of the hexagonal close-packed structure to a Gaussian function can be set to 15° or less. The above maximum reduction ratio is preferably 30% or less. 【0051】 Furthermore, by performing heat treatment under the above conditions, the grain boundary length per unit area is increased to 50 mm. －１ The following is possible: 【0052】 In this embodiment, the "β transformation point" refers to the boundary temperature at which the α phase begins to form when the titanium alloy is cooled from the β-phase single-phase region. The β transformation point is obtained from the phase diagram. The phase diagram is obtained, for example, by the CALPHAD (Computer Coupling of Phase Diagrams and Thermochemistry) method. Specifically, the phase diagram of the titanium alloy is obtained by the CALPHAD method using Thermo-Calc, an integrated thermodynamic calculation system from Thermo-Calc Software AB, and a predetermined database (TI3), and the β transformation point is calculated. 【0053】 The heat treatment may be carried out in an air atmosphere, an inert atmosphere, or a vacuum atmosphere. However, if oxide scale is formed on the titanium plate, the oxide scale must be removed. The removal of oxide scale is not particularly limited and may be carried out by, for example, shot blasting, shot blasting followed by pickling, or by machining such as polishing or cutting. However, in order to avoid introducing strain into the titanium plate, it is preferable to remove the oxide scale by machining. Furthermore, the annealing method is not particularly limited and may be a continuous heating method or a batch heating method. 【0054】Post-processing may include removal of oxide scale and other contaminants, as well as cleaning, and may be applied as needed. Additionally, titanium plates may be straightened as part of the post-processing. Examples of straightening methods include vacuum creep flattening (VCF). 【0055】 A titanium plate according to one embodiment of the present invention is used as a material for a drum for copper foil manufacturing (copper foil manufacturing drum). Therefore, the titanium plate according to this embodiment can also be said to be a titanium plate for copper foil manufacturing drums. When used in a copper foil manufacturing drum, one side of the titanium plate constitutes the cylindrical surface of the drum. 【0056】 The embodiments of the present invention will be described in detail below with reference to examples. The examples shown below are merely examples of the present invention, and the present invention is not limited to the examples below. 【0057】 First, titanium material with the chemical composition shown in Table 1 was obtained by hot forging an ingot prepared by the vacuum arc remelting method. In Table 1, "-" indicates that the value is below the detection limit. 【0058】Next, the obtained titanium plate material was heated to the heating temperature shown in Table 2 (first step), and hot rolling was performed under the conditions shown in Table 2 (second step). In the table, "Percentage of reduction ratio between 200°C and 650°C" refers to the percentage of the total reduction ratio in hot rolling that is accounted for by rolling between 200°C and 650°C, and "Maximum reduction ratio per pass between 200°C and 650°C" refers to the maximum reduction ratio among the reduction ratios of each pass between 200°C and 650°C (100 × (thickness before rolling - thickness after rolling) / thickness before rolling). "Rolling ratio (L / T)" indicates the L / T value when L (%) is the reduction ratio due to rolling in the final rolling direction and T (%) is the reduction ratio due to rolling in a direction perpendicular to the final rolling direction. Therefore, examples where a numerical value is entered in the rolling ratio column indicate that cross-rolling was performed at that rolling ratio. Examples where "-" is written in the rolling ratio column indicate that cross-rolling was not performed and unidirectional rolling was carried out. Also, with the exception of example No. 20, in order to roll the titanium sheet between 200°C and 650°C, hot rolling was temporarily stopped, allowed to cool to below 650°C, and then resumed. 【0059】 Next, heat treatment was performed under an atmospheric environment at the temperatures and times listed in Table 2 (third step) to obtain titanium plates with the thicknesses shown in Table 2. 【0060】 【0061】 For each example of titanium plate analysis and evaluation, the standard deviation of the Gaussian function was calculated by fitting a graph showing the area ratio of crystal grains at 5° intervals between the grain boundary length per unit area, the average grain size, the peak angle (the angle between the thickness direction of the titanium plate and the peak position of the grain accumulation), and the angle between the thickness direction and the c-axis of the hexagonal close-packed structure to a Gaussian function, using the method already described. However, the cross-section in the thickness direction was defined as being at the center of the width direction of the titanium plate, with the longitudinal side at least 200 mm inward from the edge, and the region of thickness × 50 μm was defined as being at the center of the width direction in the above cross-section. 【0062】 The surface of each titanium plate was polished with #1000 grit, and 60g / L-Cu + 60g / L-H was applied. ２ SO ４The titanium plate was immersed in an electrolytic cell containing an aqueous copper sulfate solution. The electrode plate, positioned opposite the surface of the titanium plate while immersed in the aqueous copper sulfate solution, was subjected to a flow rate of 20 A / dm² while stirring with a stirrer at a liquid temperature of 50°C. ２ A current was passed through the titanium plate for 180 seconds to electrodeposit copper foil. The electrodeposited copper foil was peeled off the titanium plate to obtain copper foil. The smoothness of the obtained copper foil was evaluated using a laser microscope (Keyence VK9700) in the following manner. Specifically, data was acquired at a magnification of 500x using the above apparatus. Using analysis software (VK Analyzer (Ver. 2.5.0.1, Keyence)) to analyze the data, the line roughness was analyzed with cutoff values ​​of λs = 2.5 μm and λc = 0.8 mm, and the surface roughness Ra was calculated at five locations. λs and λc are defined in JIS B 0601:2013 Geometric Product Specification (GPS) - Surface Texture: Contour Method - Terms, Definitions and Surface Texture Parameters. λs is called the contour filter and is a filter that defines the boundary between the roughness component and the shorter wavelength component. λc is called a contour curve filter and is a filter that defines the boundary between the roughness component and the waviness component. If the average value of the surface roughness Ra at the five points was 0.4 μm or less, it was considered a pass (A), and if the average value exceeded 0.4 μm, it was considered a fail (B). The results are shown in Table 2. 【0063】 【0064】 As shown in Table 2, examples No. 1-4, 6, 7, 9-13, 15-20, and 23 have titanium plates with the above-described chemical composition and a grain boundary length of 50 mm per unit area. －１ The following is observed: In the graph showing the area ratio of crystal grains at each angle formed by the thickness direction and the c-axis of the hexagonal close-packed structure, the standard deviation of the Gaussian function was 15° or less, indicating excellent smoothness. 【0065】In example No. 5, the Fe content was excessive, resulting in a long grain boundary length per unit area and inferior smoothness. In example No. 8, the Cu content was excessive, causing the standard deviation of the Gaussian function to exceed 15° in the graph showing the area ratio of crystal grains at each angle between the plate thickness direction and the c-axis of the hexagonal close-packed structure. As a result, the smoothness was inferior. In example No. 14, the O content was excessive, making the titanium plate excessively hard and unable to be wound onto the inner drum. Since it was not possible to manufacture copper foil by winding the titanium plate onto the inner drum, the smoothness was not evaluated. In example No. 21, the heat treatment conditions were insufficient, causing the grain boundary length and standard deviation per unit area to be outside the range of the present invention, resulting in inferior smoothness. In example No. 22, the heating temperature in the first step was excessive, causing the standard deviation to be outside the range of the present invention, resulting in inferior smoothness. In example 24, rolling was not performed in the temperature range of 200 to 650°C, resulting in a standard deviation outside the range of the present invention and inferior smoothness. In example 25, the maximum reduction ratio per pass during rolling in the temperature range of 200 to 650°C was excessive, resulting in a standard deviation outside the range of the present invention and inferior smoothness. 【0066】 1. Copper foil manufacturing apparatus 2. Electrodeposition drum 10. Electrolytic cell 30. Electrode plate 40. Winding section 50. Guide roll 60. Winding roll A. Copper foil 20. Electrodeposition drum 21. Inner drum 22. Titanium ring

Claims

1. The chemical composition is as follows (by mass%): Fe: 0.010-0.045%, O: 0.010-0.150%, Cu: 0-1.00%, Al: 0-2.00%, Sn: 0-2.00%, Zr: 0-2.00%, C: 0-0.080%, N: 0-0.050%, and H: 0-0.015%, with the remainder being Ti and impurities; and the grain boundary length per unit area is 50 mm. －１ A titanium plate characterized in that, as described below, the standard deviation of the Gaussian function obtained by fitting a graph showing the area ratio of crystal grains at 5° intervals between the angle between the plate thickness direction and the c-axis of the hexagonal close-packed structure to a Gaussian function is 15° or less.

2. The titanium plate according to claim 1, wherein when the peak position of the degree of grain accumulation is displayed using a (0001) pole figure from the thickness direction, the peak position of the degree of grain accumulation is within 30° from the normal direction of the surface of the titanium plate.

3. The titanium plate according to claim 1 or 2, wherein the thickness is 4.0 to 20.0 mm.

4. The chemical composition is as follows (by mass%): Fe: 0.010-0.045%, O: 0.010-0.150%, Cu: 0-1.00%, Al: 0-2.00%, Sn: 0-2.00%, Zr: 0-2.00%, C: 0-0.080%, N: 0-0.050%, and H: 0-0.015%, with the remainder being Ti and impurities, and the grain boundary length per unit area is 50 mm. －１ A titanium ring characterized in that the standard deviation of the Gaussian function obtained by fitting a graph showing the area ratio of crystal grains at 5° intervals, where the angle between the plate thickness direction and the c-axis of the hexagonal close-packed structure is 15° or less, to a Gaussian function.

5. The titanium ring according to claim 4, wherein when the peak position of the grain density is displayed using a (0001) pole figure from the thickness direction, the peak position of the grain density is within 30° from the normal direction of the surface of the titanium ring.

6. The titanium ring according to claim 4 or 5, wherein the thickness is 4.0 to 20.0 mm.

7. A copper foil manufacturing drum comprising a cylindrical inner drum and a titanium plate according to claim 1 or 2 or a titanium ring according to claim 4 or 5, which is attached to the outer circumferential surface of the inner drum.

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