Description Title of Invention: ALUMINUM ALLOY COLD-ROLLED SHEET FOR BOTTLE CAN Technical Field [0001] The present invention relates to a raw-material sheet for a bottle can. In particular, the invention relates to an aluminum alloy cold-rolled sheet for a bottle can. The aluminum alloy cold-rolled sheet of the invention is a rolled sheet (cold-rolled sheet) formed through hot rolling and cold rolling, which refers to a simple cold-rolled sheet or a refined sheet subjected to further heat treatment. Hereinafter, aluminum alloy may be referred to as Al alloy. Background Art [0002] Two-piece aluminum cans produced by seaming a can body and can lids (can ends) together are frequently used as aluminum-based beverage cans. The can body is manufactured as follows: an aluminum-based cold-rolled sheet is subjected to DI working (Drawing and Ironing), and is then trimmed into a predetermined size, and the trimmed sheet is degreased and washed and is then subjected to coating, printing, and baking, and finally a marginal part of the can body is necked and flanged. Hereinafter, a can manufactured in this manner may be referred to as DI can. [0003] Hard sheets including Al-Mg-Mn based alloy such as JIS 3004 alloy and JIS 3104 alloy have been widely used As a cold-rolled sheet for the can body. The JIS 3004 alloy and JIS 3104 alloy each have excellent ironing workability, and thus exhibits a relatively good formability even if the alloy is cold-rolled at a high draft ratio to increase strength. Accordingly, these alloys are each regarded to be a preferred raw material for the DI can body. [0004] 1 Among the aluminum-based beverage cans, a bottle can (aluminum bottle) having a threaded opening is manufactured as follows: an aluminum alloy sheet is subjected to surface preparation such as chromate treating, and is then covered with a resin (resin application or film lamination). The aluminum alloy sheet with such a resin coating is punched into a circular blank that is then formed into a cup shape. In this way, the bottle can (a three-piece type described later) is slightly different from the manufacturing process of the DI can in that the bottle can is formed after formation of a thermoplastic resin coating layer (resin application or film lamination) on each side of the aluminum alloy sheet. [0005] The blank formed into the cup shape is further formed into a bottle can through steps of drawing and ironing, formation of a top dome, trimming, printing and coating, threading and curing, and necking and flanging. In the drawing and ironing (DI working), the cup-shaped product is redrawn and stretched or ironed to reduce a diameter of its body, so that a bottomed, cylindrical can having a reduced thickness is formed. A portion near the bottom of the bottomed, cylindrical can is then drawn more than once to form a shoulder and an opening that is still unopened. The printing and coating are performed onto the can body after the washing and trimming. The opening is then opened before formation of the curled portion and the threaded portion (threading and curing). Furthermore, a portion on a side opposite to the threaded portion is necked in and flanged (formation of a neck and a flange), and then a separately formed bottom cover is seamed with a seamer to produce a bottle can (see PTL1). [0006] Each of the bottle can and the DI can currently has a sidewall having a thickness of about 110 gm, which is required to be further reduced for weight reduction. To achieve such a small thickness, it is important to increase strength of a material to prevent the can from having a reduced buckling strength. Furthermore, low earing in ironing is also strongly demanded. A reduction in earing in ironing may improve yield in ironing, and 2 may prevent rupture of the can body due to break of an ear of the can body. [00071 In manufacturing of the can body, blanks for cans are picked at a plurality of positions (portions) different in a width direction of an aluminum alloy sheet as a raw material (an original sheet). The aluminum alloy sheet is not always provided with uniform properties in a sheet width direction depending on a manufacturing process of the aluminum alloy sheet as a raw material. In most cases, properties of the sheet vary in the sheet width direction. Hence, even if earing of the raw material sheet is low on an average, a level of the earing may vary between the positions in the sheet width direction. If such variations in earing occur, can bodies are less likely to be stable produced in high yield. [0008] Various techniques have been proposed to reduce the earing itself. Most of the techniques are in common in that, in a process including homogenization heat treatment (hereinafter, appropriately referred to as homogenization treatment or soaking), rough hot rolling, and rough hot rolling, the homogenization heat treatment is performed at a relatively high temperature, and the hot-rolled sheet subjected to the hot rolling is uniformly recrystallized in a sheet width direction to produce a sheet that is uniformly recrystallized in the sheet width direction. [0009] For example, PTL2 proposes a technique where a texture with a preferential cubic orientation is adequately formed to reduce earing of an aluminum alloy sheet for a can body. Thus, PTL2 proposes homogenization heat treatment at a high temperature of 530 to 630*C. In particular, PTL2 specifies a finish hot-rolling condition in detail. [0010] PTL3 describes ear formation due to crystallographic anisotropy of a rolled material. PTL3 further describes that height of an ear is determined by balance of texture components (mainly 0* to 90' ears) of crystal grains in a cube orientation formed through recrystallization growing after hot rolling, and a 3 rolled texture component (45* ear) formed through cold rolling. PTL3 proposes a method of manufacturing an aluminum alloy cold-rolled sheet for a can body subjected to soaking at a relatively high temperature of 560 to 620*C on the assumption that a condition of soaking as an upstream step is also important in addition to a hot-rolling condition in order to achieve a reduction in earing, which is strictly required in association with a reduction in can diameter. [0011] In addition, even if earing itself is reduced, a cold-rolled sheet with unstable earing, in which variations in earing are not reduced in the width direction of the cold-rolled sheet, is not necessarily a good material. Thus, proposals have also been made to reduce variations in earing. [0012] For example, in PTL4, a slab is subjected to homogenization heat treatment at a high temperature of 540 to 610 0 C. This is because the homogenization heat treatment at the temperature of less than 540 0 C leads to dense distribution of precipitates, which hinders recrystallization just after hot rolling. PTL4 further proposes that the finish temperature of rough hot rolling is specified to be 430 0 C or more. Consequently, in PTL4, variations in growth of recrystallization in a sheet width direction, which may occur between a sheet center in the width direction, at which recrystallization readily grows due to relatively high temperature, and a sheet end in the width direction, at which recrystallization does not actively occur due to relatively low temperature, are reduced in a period before start of the subsequent finish hot-rolling step. Moreover, in PTL4, the finish temperature of finish hot rolling is specified within a range of 330 to 360"C in order to produce a recrystallization state just after hot rolling, and to reduce the earing itself by developing an appropriate cube orientation during process annealing in the process of the subsequent cold rolling. [0013] PTL5 proposes that a difference in area ratio between crystal grains in cube orientation in a region from a sheet surface to a 4 thickness center is reduced in a section of an aluminum alloy hot-rolled sheet, so that a good material with a stable earing in a sheet width direction is produced. Thus, in PTL5, the aluminum alloy sheet is subjected to homogenization treatment at a high temperature of about 600 to 620*C to uniformly distribute an Al-Mn-Fe-Si-based intermetallic compound phase and a precipitate-free zone (PFZ) that provides nuclei of the crystal grains in Cube orientation during a hot rolling step. Moreover, PTL5 recommends two homogenization heat treatments called two-soaking, in which the aluminum alloy sheet is temporarily cooled after the soaking (first soaking), and is then subjected to second homogenization heat treatment in which the aluminum alloy sheet is reheated to a temperature equal to or slightly higher than the start temperature of rough hot rolling and is then held at the temperature for about several hours. [0014] PTL6 proposes that the average dissolved amount of Mn in a hot-rolled sheet is controlled within a range of 0.12 to 0.38 mass%, and the average dissolved amount of Cu within a range of 0.01 to 0.3 mass%. Consequently, in PTL6, even if a cold-rolled sheet is manufactured without process annealing, earing is reduced after DI forming of the cold-rolled sheet. PTL6 has reached the following findings: an increase in average dissolved amount of Mn or Cu facilitates development of the Cube orientation, leading to a tendency of a reduction in average earing of the hot-rolled sheet. In an existing method where process annealing is performed after hot rolling, variations in microstructure are temporarily cancelled by the process annealing to stabilize earing. In contrast, according to PTL6, the average earing can be stabilized without process annealing. In PTL6, however, the temperature of the homogenization heat treatment is also relatively high, about 550 to 650 0 C, and thus the homogenization heat treatment is performed in two or more stages as in two-soaking. [0015] PTL7 also proposes that an aluminum alloy sheet is subjected to two-soaking where the aluminum alloy sheet is subjected to homogenization treatment at a high temperature of 5 about 550 to 650 0 C, and is then temporarily cooled and reheated before rough hot rolling. As a result, in PTL7, the average dissolved amount of Mn in a hot-rolled sheet and crystal grain size thereof are each controlled within a predetermined range to stably adjust earing of the hot-rolled sheet to be -3 to -6%. PTL7 further proposes that the hot-rolled sheet is then cold-rolled without process annealing to stably adjust earing of the resultant cold-rolled sheet to be 0 to 2%. [0016] In addition, with a DI can rather than the bottle can, PTL8 proposes that the homogenization treatment temperature is specified to be a high temperature of 600 to 640 0 C, so that a B phase being an Alo(Mn, Fe)-phase crystallized product formed during casting is transformed to an a phase (an Al-Mn-Fe-Si-based compound) to increase the area ratio of the a phase to be 50% or more. In PTL8, the a phase is used to prevent burn-in during ironing into the DI can. Citation List Patent Literature [0017] PTL 1: Japanese Unexamined Patent Application Publication No. 2001-162344. PTL 2: Japanese Unexamined Patent Application Publication No. 9-268355. PTL 3: Japanese Unexamined Patent Application Publication No. 10-310837. PTL 4: Japanese Unexamined Patent Application Publication No. 2008-156710. PTL 5: Japanese Unexamined Patent Application Publication No. 2004-244701. PTL 6: Japanese Patent No. 4205458. PTL 7: Japanese Unexamined Patent Application Publication No. 2003-342657. PTL 8: Japanese Unexamined Patent Application Publication No. 2000-248326. 6 Summary of the Invention Problems that the Invention is to Solve [0018] The bottle can includes a two-piece bottle can manufactured through internal and external coating on a formed aluminum sheet ("two-piece type" configured of an integrally formed can body and a cap), and a three-piece bottle can manufactured through forming a raw material beforehand laminated with a film into a can body ("three-piece type" configured of a can body, a bottom cover, and a cap). The technology of the invention is applied to the latter. In the three-piece type, during ironing for further forming a tap on the top of the can body formed in the cup shape, a flange in the periphery of the bottom of the can body, which remains in the previous forming step of the cup-shaped can body, is intentionally left. After forming of the tap (after the ironing), the flange is removed by trimming. [00191 In the three-piece bottle can, if earing itself can be reduced, and if variations in earing in a sheet width direction can be reduced, the amount of flange removed by trimming (trimming amount) can be decreased, which particularly leads to improvement in material yield. In addition, it is currently required not only to improve the properties, such as a reduction in variations in earing in a sheet width direction, but also to reduce manufacturing cost of a raw-material sheet in order to reduce thickness of the bottle can for weight reduction. In other words, as a difficult issue, both a reduction in manufacturing cost of a cold-rolled sheet as raw-material for a can and a reduction in variations in earing in a sheet width direction must be achieved though an existing manufacturing condition, which has been used to reduce variations in earing in a sheet width direction, may be modified. [0020] The above-described existing techniques cannot address such a requirement of a reduction in manufacturing cost together with improvement in earing. One of the existing techniques proposes that a hot-rolled sheet is cold-rolled without process annealing as described above. The existing techniques, however, 7 do not lead to a significant reduction in manufacturing cost together with a reduction in earing of a cold-rolled sheet as a raw material for a can and/or a reduction in variations in earing in a sheet width direction, for example, the homogenization heat treatment is still performed at the high temperature, and the homogenization heat treatment is performed twice. [0021] The object of the invention, which has been made in light of such problems, is to reduce manufacturing cost of an aluminum alloy cold-rolled sheet as a raw material for a bottle can, and to reduce variations in earing in a sheet width direction. Means for Solving the Problems [0022] To achieve the above object, an aluminum alloy cold-rolled sheet for a bottle can of the invention is summarized as follows. (1) An aluminum alloy cold-rolled sheet for a bottle can, characterized by having a composition including 0.3 to 1.2 mass% Mn, 1.0 to 3.0 mass% Mg, 0.3 to 0.7 mass% Fe, and 0.1 to 0.5 mass% Si, a mass composition ratio of the Fe to the Mn (Fe/Mn) being within a range of 0.45 to 1.5, with the remainder including Al and inevitable impurities, wherein an average number density of dispersed particles in the aluminum alloy cold-rolled sheet for a bottle can is less than three per square millimeter, the dispersed particles each having a barycentric diameter of less than 1 pm and being measurable by a transmission electron microscope at a magnification of 20,000, the sheet contains a 8 phase being an Al(Fe, Mn)-based intermetallic compound, and an Q phase being an Al-Fe-Mn-Si-based intermetallic compound, and a ratio (HB/Ha) of a largest height HB of an X-ray diffraction peak within a range of 20=20.5 to 21.50, the peak being measured by an X-ray diffraction analyzer and regarded as a diffraction peak of the 8 phase, to a largest height Ha of an X-ray diffraction peak within a range of 20=25.5 to 26.50, the peak being measured by an X-ray diffraction analyzer and regarded as a diffraction peak of the a phase, is 0.50 or more. 8 (2) The aluminum alloy cold-rolled sheet according to (1), further containing at least one selected from 0.05 to 0.5 mass% Cu, 0.001 to 0.3 mass% Cr, and 0.05 to 0.5 mass% Zn. (3) The aluminum alloy cold-rolled sheet according to (1) or (2), further containing 0.005 to 0.2 mass% Ti, or further containing 0.005 to 0.2 mass% Ti and 0.0001 to 0.05 mass% B. [0023] Although the invention controls the dispersed particles (the a phase and the 6 phase) after soaking and before hot rolling as described later, the invention specifies a state of a cold-rolled sheet. Depending on a manufacturing condition, the distribution of the dispersed particles does not change even if the ingot is further subjected to hot rolling and cold rolling, and is not substantially changed. in a hot-rolled or cold-rolled sheet as long as the manufacturing condition is within the range specified in the invention. The invention, therefore, specifies the microstructure after soaking and before hot rolling with a cold sheet as a final raw material for a bottle can, which is readily analyzed, rather than an intermediate product such as a slab or a hot-rolled sheet, which is difficult to be analyzed. Advantage of the Invention [00241 The invention is similar to existing technologies in securing uniform recrystallization of a hot-rolled sheet in a sheet width direction to reduce variations in earing in the sheet width direction. Contrary to the existing technologies, however, the invention specifies the soaking temperature to be as low as possible. Specifically, - the invention is characterized in that the microstructure after soaking and before hot rolling has a certain amount of coarse dispersed particles accelerating recrystallization. [0025] The variations in earing in a sheet width direction are caused by variations in growth of recrystallization after a raw material sheet for a can has been hot-rolled. In the hot rolling step, while recrystallization grows at an end in the width direction of the raw material sheet for a can (hot-rolled sheet), to which a relatively large amount of strain is introduced, recrystallization is 9 less likely to occur at the center, particularly .in the thickness center, in the width direction of the raw material sheet (hot-rolled sheet) for a can, to which a relatively small amount of strain is introduced. This phenomenon also affects a subsequent cold-rolled sheet, resulting in a large variation due to an ear of a final sheet (formed can). [00261 In contrast, the invention controls a state of dispersed particles in a slab after the homogenization heat treatment (soaking) and before hot rolling in order to reduce variations in earing in the width direction of the final sheet. In addition, the invention increases the proportion of the B phase being the relatively coarse Alo(Fe, Mn)-based intermetallic compound that accelerates recrystallization, but decreases the proportion of the a phase being the relatively fine Al-Fe-Mn-Si-based intermetallic compound that hinders recrystallization. Through such balance control of the proportions of the B phase and the a phase, recrystallization is accelerated at the center, particularly in the thickness center, in the width direction of the raw material sheet (hot-rolled sheet) for a can to uniformalize recrystallization rate in the width direction of the hot-rolled sheet, leading to a reduction in variations in earing in the width direction of the final sheet. In addition, although the proportion of a fine a phase is regulated, the proportion of a relatively coarse a phase is controlled so as not to be excessively decreased. [0027] The invention, therefore, specifies the soaking temperature to be as low as possible below 550 0 C, and adjusts a condition of hot rolling, in particular, rough hot rolling. In this way, the invention controls the proportion of the B phase, which accelerates recrystallization, to be increased, but the proportion of the fine a phase, which hinders recrystallization, to be decreased particularly through devising a manufacturing process of a hot-rolled sheet. [0028] In contrast, in the above-described existing techniques, the B phase formed during casting is dissolved, and the amount of dissolved Fe and/or the amount of dissolved Mn also increase due to 10 the soaking at a relatively high temperature of 520*C or more, or the two-soaking, resulting in suppression of growth of recrystallization in the hot-rolled sheet. For example, in PTL4, although a microstructure having a dense distribution of precipitates, which hinders recrystallization, is intended to be prevented from being formed in order to achieve a microstructure that accelerates recrystallization, a slab is subjected to homogenization heat treatment at a high temperature of 540 to 610 0 C. In PTL8, the homogenization treatment temperature is also performed at a high temperature of 600 to 640*C, so that the B phase formed during casting is actively transformed to the a phase to increase the a phase, and the amount of dissolved Fe and/or the amount of dissolved Mn also increase, leading to hinder recrystallization. [0029] Hence, the existing manufacturing methods cannot achieve the reduction in manufacturing cost of a raw material sheet through simplification of a process such as one-time homogenization heat treatment and lowering of the soaking temperature, together with a reduction in earing itself of the raw material sheet for a can and/or a reduction in variations in earing in a sheet width direction. As a result, the existing manufacturing methods cannot decrease the amount (trimming amount) of the flange, which remains in forming of the can body, in the periphery of the bottom of the can body of the three-piece can among the bottle cans. [0030] In contrast, the invention can achieve a reduction in earing itself of a raw material sheet for a can and/or a reduction in variations in earing in a sheet width direction while achieving a reduction in manufacturing cost of a raw material sheet through simplification of a process such as one-step homogenization heat treatment, and through low soaking temperature. As a result, the invention can decrease the trimming amount during forming of the can body of the three-piece can among the bottle cans. Brief Description of the Drawings 11 [0031] Fig. 1 is an explanatory chart illustrating distribution of diffraction peaks in an X-ray diffraction line of a cold-rolled sheet of the invention measured by an X-ray diffraction analyzer. Mode for Carrying Out the Invention [0032] (Composition of Al Alloy Cold-rolled Sheet) A chemical composition of an aluminum alloy cold-rolled sheet (slab) according to the invention is now described below together with the reason for limiting the content of each element. [0033] The chemical composition of the aluminum alloy cold-rolled sheet of the invention must satisfy the properties such as the formability into a can and the strength, which are required as a raw material for a bottle can, and satisfy the microstructure specified in the invention in terms of the chemical composition. Thus, the aluminum alloy cold-rolled sheet according to the invention has a composition including 0.3 to 1.2 mass% Mn, 1.0 to 3.0 mass% Mg, 0.3 to 0.7 mass% Fe, and 0.1 to 0.5 mass% Si, a mass composition ratio of the Fe to the Mn (Fe/Mn) being within a range of 0.45 to 1.5, with the remainder including Al and inevitable impurities. [0034] In addition to the above composition, the aluminum Alloy cold-rolled sheet according to the invention may further contain at least one selected from 0.05 to 0.5 mass% Cu, 0.001 to 0.3 mass% Cr, and 0.05 to 0.5 mass% Zn, and/or 0.005 to 0.2 mass% Ti or and/or 0.005 to 0.2 mass% Ti and 0.0001 to 0.05 mass% B. Hereinafter, the meanings of the specifications of the elements are described in order. [0035] (Mn: 0.3 to 1.2 mass%) Mn is an effective element contributing to improvement in strength and formability. In particular, since the can body material (cold-rolled sheet) of the invention is ironed during DI forming, Mn is extremely important. Mn forms various coarse Mn-based intermetallic compounds such as the B phase. Such 12 coarse compounds contribute to acceleration of recrystallization of a hot-rolled sheet, and are each effective for increasing strength of a product sheet. If the content of Mn is excessively low, the above-described effects are not exhibited. The content of Mn is therefore 0.3 mass% or more, preferably 0.4 mass% or more. On the other hand, if the content of Mn is excessively high, production of the Al-FeMn-Si based intermetallic compound (the a phase) increases, which hinders recrystallization of the hot-rolled sheet. In addition, a huge primary-phase metallic compound of Mn and Al is easily crystallized, resulting in degradation in formability. Hence, the upper limit of the Mn content is 1.2 mass%, preferably 1.1 mass%, and more preferably 1.0 mass%. [0036] (Mg: 1.0 to 3.0 mass%) Mg is effective in that Mg can improve strength by itself through solution strengthening. If the content of Mg is low, production of MgSi compounds decreases and an excessive amount of Si remains, resulting in an increase in production of the Al-Fe-Mn-Si based intermetallic compound (the a phase). The content of Mg is therefore 1.0 mass% or more, preferably 1.2 mass% or more. On the other hand, if the content of Mg is excessively high, work hardening readily occurs, leading to a significant reduction in formability. Hence, the upper limit of Mg content is 3.0 mass%, preferably 2.5 mass%. [0037] (Fe: 0.3 to 0.7 mass%) Fe serves to fine crystal grains, and contributes to accelerate recrystallization of the hot-rolled sheet through increasing production of the coarse B phase. Moreover, Fe is also useful in accelerating crystallization and precipitation of Mn to control the average dissolved amount of Mn and/or the dispersed state of the Mn-based intermetallic compounds in an aluminum matrix. The content of Fe is therefore 0.3 mass% or more, preferably 0.4 mass% or more. On the other hand, if the content of Fe is excessively high, a huge primary-phase intermetallic compound having a diameter of more than 15 p]m is easily formed, resulting in degradation in formability. Hence, the upper limit of the Fe content is 0.7 mass%, 13 preferably 0.6 mass%. [00381 The mass composition ratio of Fe to Mn (Fe/Mn) is specified within a range of 0.45 to 1.5, preferably 0.6 to 1.4 in order to reduce the number density of fine particles (the a phase) each having a diameter of less than 1pm, and increase the amount of coarse B phase to be nucleation sites for recrystallization. If the ratio is smaller than 0.45, production of the 6 phase is reduced due to the excessively small amount of Fe with respect to Mn, leading to an increase in number density of fine particles (the a phase) each having a diameter of less than 1pm. On the other hand, if the ratio exceeds 1.5, production of the a phase is excessively reduced, resulting in degradation in ironing workability. [0039] (Si: 0.1 to 0.5 mass%) Si forms the Al-Fe-Mn-Si-based intermetallic compound (a phase). Adequate distribution of the a phase improves formability. The content of Si is therefore 0.1 mass% or more, preferably 0.2 mass% or more. On the other hand, an excessively high content of Si suppresses recrystallization of the hot-rolled sheet, leading to an increase in variations in earing. Hence, the upper limit of the Si content is 0.5 mass%, preferably 0.4 mass%. [0040] (Cu: 0.05 to 0.5 mass%) Cu increases strength through solution strengthening. Hence, if Cu is selectively contained, the lower limit of the Cu content is 0.05 mass%, preferably 0.1 mass%. On the other hand, an excessively high content of Cu leads to an excessively high hardness though it facilitates high strength, resulting in degradation in formability and in corrosion resistance. Hence, the upper limit of the Cu content is 0.5 mass%, preferably 0.4 mass%. [0041] Other strengthening elements, each having an effect similar to that of Cu, include Cr and Zn. Hence, one or both of Cr and Zn may be selectively contained in addition to Cu. [00421 (Cr: 0.001 to 0.3 mass%) 14 Cr is also an effective strengthening element. The content of Cr is, for example, 0.001 mass% or more, preferably 0.002 mass% or more. On the other hand, an excessively high content of Cr leads to formation of huge crystallized products, resulting in degradation in formability. For example, the upper limit of the Cr content is about 0.3 mass%, preferably about 0.25 mass%. [0043] (Zn: 0.05 to 0.5 mass%) Zn is also an effective strengthening element. The content of Zn is 0.05 mass% or more, preferably 0.06 mass% or more. On the other hand, an excessively high content of Zn leads to degradation in corrosion resistance. The upper limit of the Zn content is about 0.5 mass%, preferably about 0.45 mass%. [0044] (Ti: 0.005 to 0.2 mass%) Ti is an element for fining crystal grains. Hence, it is preferred that Ti is selectively contained to exhibit the effect of fining crystal grains. In such a case, the content of Ti is 0.005 mass% or more, preferably 0.01 mass% or more. An excessive content of Ti leads to crystallization of a huge Al-Ti-based intermetallic compound, which hinders formability. Hence, the upper limit of the Ti content is 0.2 mass%, preferably 0.1 mass%. [0045] Ti may be contained singly, or may be contained together with a slight amount of B. If B is contained together, the effect of fining crystal grains is further improved. Thus, if B is selectively contained, the content of B is 0.0001 mass% or more, preferably 0.0005 mass% or more. On the other hand, an excessively high content of B leads to formation of coarse Ti-B based particles, resulting in degradation in formability. Hence, the upper limit of the B content is 0.05 mass%, preferably 0.01 mass%. [0046] Any element other than the above-described elements is an inevitable impurity. Although it is preferred that the content of any inevitable impurity is essentially low so as not to degrade the above-described sheet properties, consideration must be made on refining cost for reducing impurities in an aluminum-alloy ingoting 15 step. Hence, the inevitable impurities may each be contained up to about the upper limit of each element of 3000-series aluminum alloy described in JIS standards within a range without degrading the sheet properties. [00471 (Microstructure of Cold-rolled Sheet) The invention not only secures the above-described composition, but also secures the composition of the main components (Mn, Fe, and Cu) of the slab after soaking and before hot rolling, and secures the amount of the 8 phase being coarse dispersed particles, which accelerate recrystallization, in relation to the a phase to be regulated, in order to secure uniform recrystallization in a width direction of a hot-rolled sheet. Although the invention controls the microstructure of the slab after soaking and before hot rolling, the invention specifies the microstructure of a cold-rolled sheet as described before. [0048] To describe again, the B phase being the intermetallic compound including Ala(Fe, Mn) specified in the invention is a coarse crystallized product formed during casting, and becomes nucleation sites for recrystallization as second-phase dispersed particles during hot rolling, and thus accelerates recrystallization in the hot-rolled sheet. On the other hand, the a phase being the intermetallic compound including Al-Fe-Mn-Si includes two types, i.e., an a phase formed through transformation from the 6 phase during soaking (coarse a phase), and an a phase newly precipitated through nucleation (fine a phase). [0049] As in the above-described existing techniques, transformation from the 6 phase to the a phase is facilitated with higher temperature or longer time in a soaking condition, and most of the a phase appearing after soaking is caused due to the transformation from the 6 phase to the a phase. Since the soaking temperature at the optimum manufacturing condition of the invention is low, less than 550'C, it is speculated that, among the a phase in the soaked sheet (cold-rolled sheet) of the invention, while a slight amount of a phase is transformed from the B phase during 16 soaking, most of the a phase is newly precipitated as fine a phase through nucleation during soaking. The 6 phase includes coarse crystallized products, but includes no fine particle having a barycentric diameter of less than 1 pm. Consequently, if the microstructure of the cold-rolled sheet of the invention is observed by a transmission electron microscope, most of the observed particles, each having a barycentric diameter of less than 1 pm, are likely to be a-phase particles that are newly precipitated through nucleation during soaking. [0050] Dispersed Particles: The invention first specifies the number average density of the fine dispersed particles, which each have a barycentric diameter of less than 1 pm, and significantly hinder recrystallization of the hot-rolled sheet, to be less than three per square millimeter in order to regulate the fine dispersed particles. Since most of the fine dispersed particles, each having a barycentric diameter of less than 1 pm, are a-phase particles that are newly precipitated through nucleation during soaking or hot rolling, such a specification substantially specifies the representative fine a phase. This reduces the particularly fine a phase itself that hinders recrystallization, and accelerates recrystallization at the center, particularly in the thickness center, in the width direction of the raw material sheet (hot-rolled sheet) for a can to uniformalize the recrystallization rate in the width direction of the hot-rolled sheet, leading to a reduction in variations in earing in the width direction of the final sheet. If the number average density is three per square millimeter or more, the particularly fine a phase increases, and recrystallization of the hot-rolled sheet is thus hindered, and consequently variations in earing in the width direction of the final sheet are failed to be reduced. [0051] Although the invention specifies the number of the fine dispersed particles each having a barycentric diameter (size) of less than 1 pm, such simple specification of the upper limit of the barycentric diameter may allow fine dispersed particles, which 17 cannot be observed or measured even by a transmission electron microscope (hereinafter, sometimes referred to as TEM), to be included in that range. Thus, the invention specifies the magnification of TEM, and further specifies dispersed particles to be measurable at the magnification to clearly determine only the measurable, fine dispersed particles. The lower limit of the barycentric diameter (size) of the dispersed particles, which can be measured reproducibly and objectively by the TEM at a magnification of 20,000, is approximately 30 nm. In addition, diffusion rate of atoms is high, and growth rate of the dispersed particles is also high in the preferred temperature range of soaking or hot rolling specified in the invention. Hence, fine particles each having a size of 30 nm or less cannot be distributed along recrystallization during hot rolling. Consequently, the invention actually measures and specifies fine dispersed particles within a range of barycentric diameter of 30 nm or more and less than 1 pm. [0052] Although the number average density of dispersed particles is typically specified per cube millimeter in view of the volume of a thin-film sample in TEM observation, the invention specifies the number average density of dispersed particles per square millimeter. The reason for this is as follows: while a sample observed by TEM is a thin film having a thickness of about 100 pm, the dispersed particles (precipitates) to be measured in the invention, which are observed in a TEM image, are three-dimensionally dispersed in the entire thin film. As a result, even if a plurality of particles are dispersed while overlapping with each other, the particles can be viewed only as one particle, i.e., are not wholly observed, in a TEM image; hence, it is principally impossible to accurately count the number of particles in a three-dimensional manner. Moreover, the thickness of the thin film is not necessarily perfectly the same over the entire area of an observation field. Thus, in the invention, for convenience, the number of dispersed particles per square millimeter is calculated, and such calculated number is defined as the number density of the dispersed particles. [0053] 18 The barycentric diameter refers to circle-equivalent size (circle-equivalent diameter) assuming that a maximum length of a dispersed particle having an indefinite shape is a diameter of a circle, which is generally used for determining size of a dispersed particle in an aluminum alloy field, for example, as shown in Japanese Unexamined Patent Application Publication Nos. 2009-1291293, 2009-215643, 2009-228111, 2009-242904, 2008-266684, 2007-126706, 2006-104561, and 2005-240113. [0054] Measurement of Number Density of Dispersed Particles: The average number density of dispersed particles each having a barycentric diameter of less than 1 pm is measured through observation of a microstructure of a cold-rolled sheet with a transmission electron microscope. In detail, a test piece from the thickness center and a test piece from the top of a rolled sheet are mirror-polished, and a microstructure of each polished surface is observed in ten viewing fields by a transmission electron microscope at 20,000 power, and the average number density per square micrometer is then calculated. In this measurement, the number of particles observed within an area of 8 pm by 8pm is determined for calculation of the number of particles per square micrometer. Since the average number density is greatly affected by sheet thickness, the thickness is fixed to 100 nm throughout the TEM observation, and a thickness error of ±20 nm is determined to be allowable. [0055 Height of X-ray Diffraction Peak: In the invention, the amount of the 6 phase is increased to accelerate recrystallization of a hot-rolled sheet. To securely increase the B phase, the fine a phase, which is newly precipitated through nucleation during soaking, is regulated as described above, and besides the a phase, which is formed through transformation from the B phase during soaking, is also regulated in relation to the B phase. Specifically, balance between the proportions of the B phase and the a phase is controlled to relatively increase the B phase, so that the amount of the B phase is secured. This accelerates recrystallization at the center, particularly in the 19 thickness center, in the width direction of the raw material sheet (hot-rolled sheet) for a can to uniformalize the recrystallization rate in the width direction of the hot-rolled sheet, leading to a reduction in variations in earing in the width direction of the final sheet. Along with this, although the fine a phase, which is newly precipitated through nucleation during soaking, is regulated, the relatively coarse a phase, which is formed through transformation from the B phase during soaking, is controlled so as not to be excessively decreased. Since the a phase formed through transformation from the B phase is coarse as the B phase, such an a phase is not included in the above-described a phase to be regulated, which is newly precipitated through nucleation during soaking as the dispersed particles, each having a barycentric diameter of less than 1 jim. [0056] In the typical DI cans, a decrease in a phase leads to a reduction in lubricating ability and in turn a reduction in ironing workability. As described above, however, the bottle can is formed in a slightly different manner from the manufacturing process of the DI cans in that the bottle can is formed after formation of a thermoplastic resin coating layer (resin application or film lamination) on each side of the aluminum alloy sheet (cold-rolled sheet). As a result, the thermoplastic resin coating layer serves as a lubricant during forming, which extremely improves can-formability. [0057] The invention minimizes a reduction in can-formability of a raw material sheet by such an lubricating effect caused by the thermoplastic resin coating layer formed before forming, and by controlling the relatively coarse a phase so as not to be excessively decreased. Specifically, the invention determines the proportion of each of the B phase and the a phase by suppressing an excessive decrease in a phase, and by controlling the balance between the proportions of the B phase and the a phase rather than by regulating the proportion of only the 8 or a phase, thereby suppresses a reduction in can-formability, and secures the can-formability in the case where the thermoplastic resin coating 20 layer is formed before forming. [0058] The invention determines the proportion of each of the B phase and the a phase (balance control) with diffraction peak intensity measured by an X-ray diffraction analyzer. A type and/or the amount of a compound (such as an intermetallic compound) as the second-phase particles in a matrix can be identified (qualification or quantification) from a position and height of an X-ray diffraction peak measured through X-ray diffraction analysis. Consequently, the technique using diffraction peak intensity of the invention is optimum for the identification (distinction), i.e., determination of the proportion, of each of the 6 phase and the a phase as the second-phase particles of the invention. [0059] Fig. 1 illustrates distribution of diffraction peaks in an X-ray diffraction line of a cold-rolled sheet of the invention (example 7 of the invention in Table 2 in Example described later) measured by an X-ray diffraction analyzer. The proportion of each of the B phase and the a phase as the second-phase particles in an aluminum alloy can be identified from a position (position on a horizontal axis) of a diffraction peak and height H (intensity in CPS) of a diffraction peak shown along a vertical axis illustrated in Fig. 1. [0060] In Fig. 1, diffraction peak distribution is shown within a measurement range of 20=10 to 1000 along the horizontal axis. Below the diffraction peak distribution (below a position of 0 on the vertical axis), diffraction peaks of crystallized products and Al are shown in order from the top at various positions on the horizontal axis by thin bar lines (bar graphs). The bar graphs for materials shown as "crystallized product" in the right indicate the a phase (shown as a-Al12(Fe, Mn)3Si), the 6 phase (shown as Alo(Fe, Mn)), and an intermetallic compound (shown as Mg2Si) in order from the top. The bar graph on the bottom indicates Al shown as "component of base material" at the right end. [0061] 21 In Fig. 1, large intensity peaks at 20 of 45* or more are known to be peaks of Al as the component of the base material (a parent phase) from compare and contrast of the diffraction peak distribution and the bar graphs. Moreover, the peaks of the a phase and the 8 phase are known to overlap with each other at most positions on the horizontal axis from the compare and contrast of the diffraction peak distribution and the bar graphs. [0062] In such a fact situation, relatively large determinable diffraction peaks, which each lie in one of the a phase and the B phase without overlapping with another peak, and can be reproducibly measured in height, are searched based on the compare and contrast of the diffraction peak distribution and the bar graphs. As a result, such a diffraction peak of the 6 phase is known to be an X-ray diffraction peak having a largest height within a range of 26=20.5 to 21.5" (near 21") as a bar line indicated by a left arrow between two arrows in Fig. 1. In addition, such a diffraction peak of the a phase is known to be an X-ray diffraction peak having a largest height within a range of 20=25.5 to 26.50 (near 26*) as a bar line indicated by a right arrow between the two arrows in Fig. 1. In other words, X-ray diffraction peaks at other positions overlap between the a phase and the 6 phase, or are each small (low) though they do not overlap, and thus cannot be reproducibly measured in height. Hence, each of the above-described X-ray diffraction peaks specified within the ranges indicated by the positions on the horizontal axis (the X-ray diffraction peaks each having the largest height within that range) can be regarded as the specific diffraction peak determining the proportion of each of the 6 phase and the a phase. [0063] Ratio of X-ray Diffraction Peak Height (HB/Ha): Thus, the invention uses the largest height HB of the X-ray diffraction peak within the range of 20=20.5 to 21.5*, which is regarded to be the diffraction peak of the B phase, and the largest height Ha of the X-ray diffraction peak within the range of 20=25.5 to 26.5*, which is regarded to be the diffraction peak of the a phase, and determines the proportion of each of the B phase and the a 22 phase with a ratio HB/Ha between them. Consequently, the proportion of the B phase is secured, and thus uniform recrystallization of the hot-rolled sheet is secured. [0064] In the invention, the lower limit of the ratio of X-ray diffraction peak height HB/Ha is specified to be 0.50. If the ratio is less than 0.50, the 6 phase excessively decreases, leading to an excessively large recrystallization suppression effect by the a phase with respect to the recrystallization acceleration effect by the B phase. This leads to fail of uniform recrystallization in a sheet width direction of the hot-rolled sheet, in order to reduce variations in earing in the sheet width direction. It is to be noted that an excessive increase in a phase (an excessive decrease in 6 phase) is not only due to the soaking condition, but also due to a manufacturing condition such as time before start of rough hot rolling, and steady rate in the rough hot rolling. [00651 In the invention, a certain amount of a phase is necessarily contained though its quantitative percentage is small compared with the 6 phase. As disclosed in PTL8, ironing workability is generally improved through dispersion of the a phase. As a result, if the amount of the a phase is excessively small, poor appearance such as a scratch called goring or burn-in may occur even in the invention due to insufficient lubrication during can-forming though the thermoplastic resin coating layer is beforehand provided. Hence, the upper limit of the ratio of X-ray diffraction peak height HB/Ha is preferably specified to be 1.8, and more preferably 1.6, to permit some a phase to be contained in order to prevent a reduction in can-formability at a level high enough to cause such a problem. Moreover, the a phase is permitted to be contained in this way, which advantageously minimizes the reduction in can-formability due to the B phase. However, if the a phase excessively increases, for example, the ratio of X-ray diffraction peak height HB/Ha exceeds the above-described upper limit value, while the can-formability is improved, earing itself as the main object of the invention is reduced. The specification with the ratio of X-ray diffraction peak height HB/Ha of the invention, i.e., the 23 specification of the proportion of each of the B phase and the a phase of the invention further has the following meaning: an excessive decrease in a phase is suppressed to control the balance between the proportions of the B phase and the a phase instead of specifying only the proportion of the B phase, so that certain can-formability is secured. [0066] Such a technique, in which the a phase or the 6 phase as the second-phase particles in the aluminum alloy is identified or determined with the X-ray diffraction peak height or the ratio of the height, is known in the aluminum alloy field by Japanese Unexamined Patent Application Publication No. 2010-116594, for example. In the patent literature, the proportion of a-phase crystallized products contained in, for example, a Si-excess Al-Mg-Si alloy sheet of AA or JIS 6000 series is increased to fine and spheroidize the precipitates being contained, so that bending workability (hemming) at a severe condition is improved. [0067] Method of Measuring X-ray Diffraction Peak: For example, an X-ray diffraction system (Model: RAD-RU300) from Rigaku Denki K. K. is used as the X-ray diffraction system used for measurement of X-ray diffraction peak height, HB, and Ha, which performs measurement using a Co target at the following condition: tube voltage 40 kV; tube current 200 mA; scan speed 1 */min; sampling width 0.02*; and measurement range (29) 10 to 1000. The largest X-ray diffraction peak height HO within the range of 20=20.5 to 21.50 (near 21*), which is regarded to be the diffraction peak of the B phase, and the largest X-ray diffraction peak height Ha within the range of 20=25.5 to 26.5"(near 26*), which is regarded to be the diffraction peak of the a phase, are determined. The largest peak heights are each determined by subtracting background from an X-ray diffraction profile. [0068] Manufacturing Method: According to a niethod of manufacturing an aluminum alloy cold-rolled sheet as a raw material for a bottle can of the invention, 24 the aluminum alloy cold-rolled sheet can be manufactured without significantly modifying the existing manufacturing process including soaking, hot rolling, and cold rolling, manufacturing cost can be reduced, and variations in earing in a sheet width direction can be reduced. [00691 To achieve the microstructure specified in the invention to reduce variations in earing of a final sheet, however, the soaking condition and the hot rolling condition must be specified as follows. Specifically, in the invention, the aluminum alloy slab having the above-described composition is subjected to one-time homogenous heat treatment at a temperature of more than 450*C and less than 550*C, and then rough hot rolling is promptly started, and promptly finished after certain rolling operation. [0070] Soaking Condition: Soaking is performed once in light of a reduction in manufacturing cost. Here, the soaking temperature is within a relatively low-temperature range of more than 450*C and less than 5500C, preferably more than 460*C to less than 5300C. As described above, the invention controls the state of the 6 phase of a slab after the homogenous heat treatment (soaking) and before hot rolling to reduce variations in earing in the width direction of the final sheet. In particular, the invention allows the B phase to be not transformed to the a phase, and maintains the B phase as a relatively coarse phase. The invention, therefore, specifies the soaking temperature to be as low as possible below 5500C so that the crystallized 6 phase is not significantly dissolved to suppress transformation of the 6 phase to the a phase. Moreover, this reduces the amount of dissolved Fe and the amount of dissolved Mn to actively increase the amount of the 8 phase being relatively coarse dispersed particles, each having a diameter of 2 to 151pm, to be a nucleation site for recrystallization of the hot-rolled sheet. [0071] This accelerates recrystallization at the center, particularly in the thickness center, in the width direction of the raw material sheet (hot-rolled sheet) for a can to uniformalize the 25 recrystallization rate in the width direction of the hot-rolled sheet, leading to a reduction in variations in earing in the width direction of the final sheet. Excessively low soaking temperature of less than 450*C, however, results in fail of homogenization and/or hot rolling of the slab. [0072] Contrary to this, in the above-described existing techniques, soaking is performed at a relatively high temperature of 520*C or more as described above, and therefore crystallized products are dissolved, or the 6 phase is transformed to the a phase due to the excessively high soaking temperature, resulting in lack of relatively coarse dispersed particles, which accelerate recrystallization of the hot-rolled sheet, specified in the invention. Moreover, in the existing techniques, the amount of dissolved Fe and the amount of dissolved Mn increase, leading to hinder growth of recrystallization of the hot-rolled sheet. Furthermore, in the existing techniques, since two-soaking is performed as a preferred embodiment, manufacturing cost cannot be reduced. [0073] The soaking time (homogenization time) is preferably as short as possible as long as the slab is homogenized, for example, the time is 12 hr or less, preferably 6 hr or less. [0074] Hot Rolling Condition: Hot rolling includes a rough rolling step for the soaked slab performed depending on thickness of a sheet to be rolled, and a finish rolling step of rolling the rough-rolled sheet having a thickness of about 40 mm or less into a thickness of about 4 mm or less. A reversing or tandem rolling mill is appropriately used for the rough or finish rolling step for multi-pass rolling. [0075] Rough Hot Rolling: In the invention, .one-time soaking is performed instead of two- or two-step soaking, in which a sheet is temporarily cooled after the soaking and is then reheated. In the invention, therefore, rough hot rolling is started at a soaking temperature within a range of 450*C to less than 550'C. The rough hot rolling start 26 temperature of less than 450 0 C leads to suppression of recrystallization of the hot-rolled sheet. On the other hand, the upper limit of the rough hot rolling start temperature is determined by the soaking temperature (upper limit 5500C). If hot rolling is started at a temperature of 550*C or more, burn-in of the sheet to a work roll occurs during hot rolling, which facilitates surface defects on the sheet. [0076] The rough hot rolling is started promptly (without temporal delay) after the soaking has been finished. The prompt start of the rough hot rolling suppresses formation of particles (the a phase) each having a diameter of less than 1pm in a period from the end of the soaking to start of the rough hot rolling. As an index for this respect, the rough hot rolling for the soaked aluminum alloy sheet is started within 15 min, preferably within 10 min. [0077] In the rough hot rolling with a reversing rolling mill, among all steady rates in several to several ten passes, the lowest steady rate is specified to be 50 m/min or more. The steady rate refers to a rolling speed (line speed) that is highest and constant per pass. If a steady rate, which is lowest among all passes in the rough hot rolling, is less than 50 m/min, product of the a phase increases due to long rolling time, resulting in suppression of recrystallization of the hot-rolled sheet. [0078] The finish temperature of the rough hot rolling is preferably 400*C or more. In the invention, hot rolling is divided into the rough rolling and the finish rolling, which are continuously performed; hence, if the finish temperature of the rough hot rolling is excessively low, rolling temperature is lowered in the subsequent finish hot rolling step, which facilitates occurrence of an edge crack. Moreover, if the finish temperature of the rough hot rolling is excessively low, self-heat necessary for recrystallization after finish rolling tends to be insufficient, which hinders growth of recrystallization of the hot-rolled sheet, leading to a reduction in uniformity of recrystallization in a sheet Width direction. [0079] 27 Finish Hot Rolling: The finish hot rolling is performed for the aluminum alloy sheet subjected to the rough hot rolling, for example, continuously and promptly (without temporal delay). The prompt start of the finish hot rolling can prevent restoration of strain accumulated during the rough hot rolling, leading to an increase in strength of a subsequently produced cold-rolled sheet. As an index for this respect, the finish hot rolling for the aluminum alloy sheet subjected to the rough hot rolling is preferably started within 5 min, preferably within 3 min. [0080] The finish temperature of the finish hot rolling is preferably 300 to 360*C. In the finish hot rolling step, the sheet is finished into a predetermined size. Since the sheet subjected to the finish hot rolling has a recrystallized microstructure due to self-heating, the finish temperature affects the recrystallized microstructure. If the finish temperature of the finish hot rolling is 3000C or more, the microstructure of a final sheet is easily into a recrystallized microstructure uniform in a sheet width direction, in conjunction with a condition of the subsequent cold rolling. If the finish temperature of the finish hot rolling is less than 300*C, the microstructure of the invention is difficult to be produced. On the other hand, if the finish temperature of the finish hot rolling exceeds 3000C, coarse compounds such as a MgSi compound are precipitated, which degrade formability, and crystal grains are coarsened, leading to a rough skin of a sheet surface. Consequently, the lower limit of the finish temperature of the finish hot rolling is 3000C, preferably 3100C. The upper limit of the finish temperature of the finish hot rolling is 360*C, preferably 3500C. [0081] A tandem hot-rolling mill having three or more stands is preferably used as a finish hot-rolling mill. The three or more stands allow a draft ratio per stand to be reduced, making it possible to accumulate strain while maintaining a surface texture of the hot-rolled sheet. This allows a further increase in strength of each of a cold-rolled sheet and a DI compact formed of the 28 cold-rolled sheet. The alloy sheet subjected to the (finish) hot rolling preferably has a thickness of about 1.8 to 3 mm. The thickness of the sheet subjected to the (finish) hot rolling of 1.8 mm or more makes it possible to prevent degradation of the surface texture of the hot-rolled sheet, such as burn-in and a rough skin, and degradation of a thickness profile. The thickness of the sheet subjected to the (finish) hot rolling of 3 mm or less makes it possible to prevent an excessive increase in draft ratio during manufacturing of a cold-rolled sheet (typically having a thickness of about 0.28 to 0.35 mm), leading to a reduction in earing after DI forming. [0082] Cold Rolling: In the cold rolling step, it is preferred that a sheet is rolled in multiple passes in a so-called straight manner without process annealing while the total draft ratio is 77 to 90%. The thickness of the cold-rolled sheet is about 0.28 to 0.35 mm in light of forming into a bottle can. A tandem rolling mill, in which rolling stands are disposed in series in two or more stages, is preferably used in the cold rolling step. Use of such a tandem rolling mill allows a reduction in number of passes (threading operations) compared with a single rolling mill having the same total draft ratio, in which a sheet is cold-rolled into a predetermined thickness through repeated passes (threading operations) with a one-stage rolling stand. As a result, a draft ratio in one threading operation can be increased. [00831 Refining: The cold-rolled sheet may be subjected to refining such as finish annealing (final annealing) at a temperature lower than the recrystallization temperature. In the cold rolling with the tandem rolling mill, however, strain can be continuously restored at a further low temperature, allowing formation of sub grains; hence, such finish annealing is basically unnecessary. Example [0084] Although the invention is now more specifically described 29 with Example, the invention should not be restricted to the Example below, and it will be appreciated that the invention can be carried out while being appropriately modified within the scope without departing from the gist described above and later, and any of such modifications is included in the technical scope of the invention. [0085] Molten metal of 3000-series Al alloy having a composition shown in Table 1 is ingoted while can-material scraps are used as an ingot material in addition to aluminum metal, and a slab 600 mm thick and 2100 mm wide is manufactured by a DC casting process. In table 1, "-" indicates that the content of a corresponding element is equal to or lower than the detection limit. [0086] Each of slabs having such compositions was soaked and hot-rolled in accordance with the condition shown in Table 2. The soaking was performed once, in which the slabs in examples were in common held for four hours at the respective treatment temperatures shown in Table 2. The slab was subjected to the soaking and then hot-rolled. A reversing rough hot-rolling mill having one stand was used for rough hot rolling. A tandem hot-rolling mill having four stands was used for finish hot rolling. In such operation, as shown in Table 2, the start temperature of the rough hot rolling, time from the end of the soaking to start of the rough hot rolling, lowest steady time in all passes of the rough hot rolling (lowest steady time in all passes), the finish temperature of the rough hot rolling (approximately equal to the start temperature of the finish hot rolling), and the finish temperature of the finish hot rolling were varied. In this way, aluminum alloy hot-rolled sheets, which in common had a thickness of 2.5 mm after the finish hot rolling, were produced. [0087] In the rough hot rolling, rolling reduction was varied depending on sheet thickness. In a large slab thickness region of original 600 mm to 100 mm or more, the slabs in the examples were in common rough-rolled in 15 passes while maximum rolling reduction per pass was 20% within a preferred range of less than 30 25% in order to achieve a relatively light pressure condition. Furthermore, in a rough rolling region with slab thickness of less than 100 mm, the number of passes in each example was in common four. [0088] The resultant hot-rolled sheet was cold-rolled in one-time threading operation (straight rolling) without process annealing by a tandem rolling mill having two-stage roll stands. Consequently, a sheet material (cold-rolled sheet) for a bottle can body having a final thickness of 0.3 mm was in common manufactured in each example. [0089] Test pieces described later were sampled from the cold-rolled, cold-rolled sheets (coils) for bottle can bodies. The mechanical properties of the test pieces were then measured according to the above-described measurement procedure. In addition, according to the above-described measurement procedure, a microstructure of each test piece was determined through measurement of the average number density (number/mm2) of dispersed particles each having a barycentric diameter of less than 1 pm, and measurement of a ratio HB/Ha between a largest height HB of an X-ray diffraction peak within a range of 20=20.5 to 21.5*, which was regarded to be a diffraction peak of the B phase, and a largest height Ha of an X-ray diffraction peak within a range of 29=25.5 to 26.5*, which was regarded to be a diffraction peak of the a phase. Furthermore, earing of each test piece was measured and evaluated. Table 2 also shows results of the measurements. [0090] (Mechanical Properties) A tensile test for measuring the mechanical properties (tensile strength and 0.2% yield strength) was conducted according to JIS Z2201, where the test piece had a shape of JIS 5 test piece, and was produced such that the longitudinal direction of the test piece corresponded to a rolling direction. The tensile test was conducted at a constant crosshead speed of 5 mm/min until the test piece was ruptured. [0091] 31 (Earing) First, blanks were sampled from two places in total, i.e., the center in a width direction of the cold-rolled sheet for a bottle can body, and one of the ends thereof. Each of the blanks was then applied with a lubricating oil (Nalco 147, from D.A. Stuart Co.), and was then formed into a cup shape through a 40% deep drawing test by an Erichsen tester for examination of earing. The test condition was as follows: blank diameter 66.7 mm; punch diameter 40 mm; R of dice-side shoulder 2.0 mm; R of punch shoulder 3.0 mm; and fold pressure 400 kgf. Mountain-valley shapes formed in eight directions, i.e., 0*, 450, 90*, 135*, 180*, 225*, 2700, and 3150 directions with the rolling direction as 0*, in the periphery of an opening of the cup produced in this way were measured, and average earing was calculated. [0092] In the invention, a range of the average earing of 0 to +3.5% was determined as an allowable range. The average earing was calculated by a known method, which is also disclosed in the above-described existing techniques, based on a development elevation of the cup produced through DI forming of a sheet material for a bottle can body. Specifically, heights of ears formed in 0", 900, 180*, and 2700 directions with the rolling direction in the development elevation of the cup as 0* (Ti, T2, T3, and T4, each being referred to as minus ear) were measured. In addition, heights of ears formed in 450, 135", 225", and 315* directions 0 (Y1, Y2, Y3, and Y4, each being referred to as plus ear) were measured. Each of the heights Y1 to Y4 and T1 to T4 is a height from the bottom of the cup. The average earing was calculated from the measurement values according to the following formula. Average earing (%) = [{(Yl+Y2+Y3+Y4)-(T1+T2+T3+T4)}/{1/2x(Y1+Y2+YS+Y4+T1+T2+T3 +T4)}]x100 [0093] The examples of the invention 1 to 12 in Table 2 each have the composition of the invention (one of alloys No. 1 to 10 in Table 1), and each have a microstructure of a cold-rolled sheet, in which the average number density of dispersed particles, each of which 32 has a barycentric diameter of less than 1 pm, and can be measured by TEM at a magnification of 20,000, is less than three per square millimeter, and a ratio HB/Ha of a largest height Ha of an X-ray diffraction peak between the 6 phase and the a phase is 0.50 or more. As a result, in the examples of the invention 1 to 10, as shown in Table 2, the average earing itself is low, and the earing less varies in the sheet width direction despite a low-cost manufacturing process including one-time and low-temperature soaking, and no process annealing. [0094] In contrast, the comparative examples 13 to 17 and 21 in Table 2 are each manufactured at a preferable manufacturing condition as in the examples of the invention. The comparative example, however, has an aluminum alloy composition (one of alloys No. 11 to 16 in Table 1) out of the composition of the invention, and therefore has a microstructure out of the specification of the invention. As a result, the average earing itself is high, and the earing significantly varies in the sheet width direction in the low-cost manufacturing process including one-time and low-temperature soaking, and no process annealing. [0095] In the comparative example 13, since the content of Si is excessively large as shown in alloy No. 11 in Table 1, the average number density of dispersed particles, each having a barycentric diameter of less than 1 pm, is excessively high, and the ratio HB/Ha of the largest height Ha of the X-ray diffraction peak between the 6 phase and the a phase is excessively low. In the comparative example 14, the content of Fe is excessively small as shown in alloy No. 12 in Table 1, and a mass composition ratio of Fe to Mn (Fe/Mn) is also excessively low. As a result, the ratio HB/Ha of the largest height Ha of the X-ray diffraction peak between the 6 phase and the a phase is also excessively low. In the comparative example 15, the content of each of Fe and Mn is excessively large as shown in alloy No. 13 in Table 1. As a result, the average number density of dispersed particles, each having a barycentric diameter of less than 1 pm, is excessively high, 33 and the ratio HB/Ha of the largest height Ha of the X-ray diffraction peak between the B phase and the a phase is excessively low. In the comparative example 16, although the individual contents of Fe and Mn are within the range of the invention as shown in alloy No. 14 in Table 1, the mass composition ratio of Fe to Mn (Fe/Mn) is excessively low. As a result, the average number density of dispersed particles, each having a barycentric diameter of less than 1 pm, is excessively high, and the ratio HB/Ha of the largest height Ha of the X-ray diffraction peak between the B phase and the a phase is excessively low. In the comparative example 17, the content of Mg is excessively small as shown in alloy No. 15 in Table 1. As a result, the average number density of dispersed particles, each having a barycentric diameter of less than 1 pm, is excessively high, and the ratio HB/Ha of the largest height Ha of the X-ray diffraction peak between the B phase and the a phase is excessively low. In the comparative example 22, the mass composition ratio of Fe to Mn (Fe/Mn) is excessively low as shown in alloy No. 16 in Table 1, and is exclusively out of the composition of the invention. However, since the content of Fe with respect to Mn is excessively small, production of the 6 phase is reduced as described before, and the number density of particles (the a phase), each having a barycentric diameter of less than 1 pm, increases. As a result, as shown in Table 2, the average number density of dispersed particles, each having a barycentric diameter of less than 1 pm, is excessively high, and the ratio HB/Ha of the largest height Ha of the X-ray diffraction peak between the B phase and the a phase is excessively low. [0096] The comparative examples 18 to 21 each have the composition of the invention (alloy No. 2 in Table 1), but each have a microstructure out of the specification of the invention since a condition such as the one-time soaking temperature and/or the finish temperature of the rough hot rolling is out of the above-described preferred condition. As a result, the average earing itself is high, and the earing significantly varies in the sheet width direction in the low-cost manufacturing process including 34 one-time and low-temperature soaking, and no process annealing. [0097] In the comparative example 18, the soaking temperature was excessively low, and cracks occurred during hot rolling, and therefore test was stopped halfway the hot rolling as shown by oblique lines in Table 2. In the comparative example 19, the finish temperature of the finish hot rolling was excessively high, and thus surface defects due to a rough skin were caused, and therefore cold rolling subsequent to hot rolling was not performed as shown by oblique lines in Table 2. In the comparative example 20, the finish temperature of the rough hot rolling and the finish temperature of the finish hot rolling are each excessively low, and thus the average number density of dispersed particles, each having a barycentric diameter of less than 1 pm, is excessively high, and the ratio HB/Ha of the largest height Ha of the X-ray diffraction peak between the B phase and the a phase is excessively low. In the comparative example 21, the soaking temperature was excessively high, and thus surface defects due to burn-in were caused, and therefore cold rolling subsequent to hot rolling was not performed as shown by oblique lines in Table 2. [0098] The above results reveal the critical meanings of the, requirements prescribed by the invention and the preferred manufacturing condition. [00991 35 c to " DLmcD;q D n - C 0*m Sd LCO CO N: CD C= O CD E"J C ) O C) C= C C- LL O0O - O Or-0000o00o0.-0 - D 00000 C J 00000 DCDCDC N J C C CN CN C C CN CN CN CD Dd)0 CD CC =1 00d O CO n ) 7 r7 "N r- r7 r r ',I CN : : r-: 0o o D mo com 0 0c0 60o 3 N OO O C? COO 0 O O 0 C C C a E U.> <o O co o D cm LO C m tO - D CD E E M "d -- o - -- L C6 L --0
-
a CD 0 N)C M LO (O <CCO Kr Lo CO r-- CO OJM e e e r EE Ea 0C( r-(0o a t CL o o a) E , 2- x > O y CD IJ- 32 -c -, 0) . a - C ta to C o O a c C O M C c aM Cn M " - C C= 79 2 m cm E1 , = m o E - o E M~ r-LMn17 CO CJ0 -,T -rCc~r2-'0 C) C CI aW7 C4'CC4O JOCO C) Ce C') I a oD C OCD - -)C)C0 0 C 4DN- -CO M C%J CO co a-jC* C"N N ci C4 S~ C C4 CC) -r r % f E o o co *C lo o M o D I oo oo 0a e~U~ w - CD ~ CO r-W- 0r O z CO C'J CV) CO 0 - M-C CO CO2 N E . o . -gt5 = o oo ooo oo ooo C to e 3 a 2 r a C . a ECo cOCo a). LS_ CC CD o m o r C)C C')CP'- CoC') coo e CDC 0- cC=- 0 0 0 0 0 0 0 0 0 0 0 0 o 01 Mc 2 0 CD .22 ~0 cm. C)Ca C)L D CD CD D -D -D C CDCON CD CD CD 0 D C-D - -DC DC CD CD CD CD -D M: 6) o -t " I- 0 r "') Nt)lt CO C O N -- COOU) 0 r C') CC C u W 0 -: )( : : DC : D C ) = DC)C DC) )C >C o )MC )0 - D 0)0)a ' 6: uo1u)u CO acdsx ;I- waxa tA1 doOM o )' rm r r' Iz O"- r t OLO rL O Industrial Applicability [0101] As described hereinbefore, according to the invention, manufacturing cost of an aluminum alloy cold-rolled sheet as a raw material for a bottle can may be reduced, and variations in earing in a sheet width direction can be reduced. Moreover, in the three-piece bottle can, the amount of flange removed by trimming (trimming amount) can be decreased through a reduction in earing itself and a reduction in variations in earing in a sheet width direction, leading to improvement in material yield. Hence, the invention is preferred for an application of manufacturing the three-piece bottle can among the bottle cans. [0102] Although the embodiment and the Example of the invention have been described hereinbefore, the invention should not be limited to the embodiment, and can be carried out in a variously modified manner within the scope described in claims. This patent application is based on Japanese Patent Application No. 2010-221623 filed on September 30, 2010 and Japanese Patent Application No. 2011-192510 filed on September 5, 2011, the contents of which are incorporated herein by reference. 38