CN116918142A - battery device - Google Patents

battery device Download PDF

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Publication number
CN116918142A
CN116918142A CN202280017442.XA CN202280017442A CN116918142A CN 116918142 A CN116918142 A CN 116918142A CN 202280017442 A CN202280017442 A CN 202280017442A CN 116918142 A CN116918142 A CN 116918142A
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CN
China
Prior art keywords
steel sheet
battery device
plated steel
flow path
cooling medium
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202280017442.XA
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Chinese (zh)
Inventor
三宅恭平
古贺敦雄
植田浩平
三日月豊
乘田克哉
松井翔
大毛隆志
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Nippon Steel Corp
Original Assignee
Nippon Steel and Sumitomo Metal Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nippon Steel and Sumitomo Metal Corp filed Critical Nippon Steel and Sumitomo Metal Corp
Priority claimed from PCT/JP2022/004683 external-priority patent/WO2022185849A1/en
Publication of CN116918142A publication Critical patent/CN116918142A/en
Pending legal-status Critical Current

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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

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  • Other Surface Treatments For Metallic Materials (AREA)

Abstract

The battery device comprises a battery pack for accommodating battery cells and a water cooling medium flow path formed outside the bottom surface of the battery pack, wherein the water cooling medium flow path is composed of a Zn-plated steel sheet, and an inorganic film or a resin film is formed on the surface of the Zn-plated steel sheet as a chemical conversion treatment film, and the inorganic film contains Si-based components or Zr-based components as main components.

Description

Battery device
Technical Field
The present application relates to a battery device.
The present application claims priority based on japanese patent application No. 2021-31920 of 1/3/1/2021/5/25/2021/87651 of the application, and their contents are incorporated herein.
Background
In the automotive field, in order to reduce CO 2 EV conversion progresses. In order to prevent degradation of a battery due to temperature rise, a cooling structure is required for a battery pack that houses a battery cell serving as a power source among components used in an EV automobile. In recent years, as the capacity of a battery increases, a water-cooled battery having a high cooling capacity has been used (for example, patent documents 1 and 2). In the water-cooled battery pack, a water cooling medium flow path through which cooling water flows is formed outside the battery pack.
Prior art literature
Patent literature
Patent document 1: japanese patent laid-open No. 2020-107443
Patent document 2: japanese patent No. 6125624
Disclosure of Invention
Problems to be solved by the invention
Here, since an LLC (long-acting coolant, which may also be referred to as long-life coolant) aqueous solution containing an organic component in the water-cooling medium flow path flows as a coolant, a member constituting the water-cooling medium flow path is required to have high corrosion resistance (coolant corrosion resistance) with respect to the coolant. In addition, when a cooling structure (specifically, a water cooling medium flow path) is provided on the outside of the battery pack, the battery pack and the cooling structure are disposed on the bottom surface portion of the automobile, and thus are exposed to the external environment. Therefore, members constituting the battery pack and the cooling structure are required to have corrosion resistance (external corrosion resistance) equivalent to that of the running portion of the automobile. That is, when the outer wall portion and the cooling structure of the water-cooled battery pack are to be constituted by iron, high coolant corrosion resistance and external corrosion resistance are required for the iron member. However, a technique for satisfying such a condition has not been proposed so far.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a novel and improved battery device which can improve not only the corrosion resistance against a coolant (coolant corrosion resistance) but also the corrosion resistance against the external environment (external corrosion resistance).
Means for solving the problems
In order to solve the above-described problems, according to one aspect of the present invention, there is provided a battery device (battery unit) including a battery pack accommodating battery cells and a water cooling medium flow path formed outside a bottom surface of the battery pack, wherein the water cooling medium flow path is formed of a Zn-based plated steel sheet, an inorganic film or a resin film is formed on a surface of the Zn-based plated steel sheet as a chemical conversion treatment film, and the inorganic film contains a Si-based component or a Zr-based component as a main component.
Here, too, it is possible that: the intervals between the water-cooling medium flow paths are 40mm or less.
In addition, it is also possible that: the bottom surface of the battery pack is formed by processing an Al-based plated steel sheet or an Al sheet, and the water-cooling medium flow path is in direct contact with the bottom surface of the battery pack.
In addition, it is also possible that: the water cooling medium flow path is joined to a flow path upper cover made of an Al-based plated steel sheet or an Al sheet, and the water cooling medium flow path is joined to the bottom surface of the battery pack via the flow path upper cover.
In addition, it is also possible that: the intervals between the water-cooling medium flow paths are 10mm to 40 mm.
In addition, it is also possible that: the water-cooling medium flow paths are spaced from each other by 10mm to 40mm, and the bottom surface of the battery pack and the water-cooling medium flow paths are joined together by a composite joint structure of a sealant and spot welding or a sealant and mechanical joint.
In addition, it is also possible that: the inorganic coating film contains at least 1 or more of a V component, a P component, and a Co component as a rust-preventive component.
In addition, it is also possible that: the rust-proof component is one or more of vanadium oxide, phosphoric acid and Co nitrate.
In addition, it is also possible that: the inorganic film or the resin film has conductivity.
In addition, it is also possible that: the inorganic film is composed of a compound phase containing 1 or more of Si-O bonds, si-C bonds, and Si-OH bonds.
In addition, it is also possible that: the thickness of the inorganic coating is more than 0 μm and less than 1.5 μm.
In addition, it is also possible that: the resin film contains a resin, an anticorrosive pigment, and a conductive pigment.
In addition, it is also possible that: the resin film contains, as a conductive pigment, any one or more of metal particles, intermetallic compound particles, conductive oxide particles, and conductive non-oxide ceramic particles, and the conductive pigment has a powder resistivity of 185×10 at 25 DEG C -6 Ω cm or less, and contains any one or more selected from the group consisting of Zn, si, zr, V, cr, mo, mn, fe and W as constituent elements.
In addition, it is also possible that: the resin film contains a conductive pigment in an amount of 1.0 mass% or more and 30 mass% or less.
In addition, it is also possible that: the resin film has an average thickness of 1.0 μm or more and 15 μm or less.
In addition, it is also possible that: the Zn-coated steel sheet is a Zn-Al-Mg-coated steel sheet, and an inorganic coating film containing a Si-based component as a main component is formed on the surface of the Zn-Al-Mg-coated steel sheet.
In addition, it is also possible that: the Zn-based plated steel sheet is a Zn-Al plated steel sheet, and a resin film is formed on the surface of the Zn-Al plated steel sheet.
Effects of the invention
According to the above aspect of the present invention, a novel and improved battery device can be provided in which not only the corrosion resistance against the coolant (coolant corrosion resistance) but also the corrosion resistance against the external environment (external corrosion resistance) can be improved.
Drawings
Fig. 1 is a cross-sectional view showing an outline of a battery device according to the present embodiment.
Fig. 2 is a cross-sectional view showing another example of the battery device according to the present embodiment.
Fig. 3 is a cross-sectional view showing another example of the battery device according to the present embodiment.
Fig. 4 is a cross-sectional view showing another example of the battery device according to the present embodiment.
Fig. 5 is a cross-sectional view showing another example of the battery device according to the present embodiment.
Detailed Description
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The numerical limitation range indicated by the term "to" is a range including the numerical values described before and after the term "to" as the lower limit value and the upper limit value. For values expressed as "above" or "below," the value is not included in the numerical range.
<1 > integral Structure of Battery device
First, the overall configuration of the battery device 1 according to the present embodiment will be described with reference to fig. 1. Fig. 1 is a cross-sectional view (a cross-sectional view perpendicular to a bottom surface portion 10a of a battery pack 10) showing an outline of a battery device 1 according to the present embodiment.
The battery device 1 of the present embodiment is provided outside (below) the bottom surface portion of the automobile. Therefore, the battery device 1 is exposed to the external environment of the automobile. Therefore, the battery device 1 is required to have corrosion resistance (external corrosion resistance) equivalent to that of the running portion of the automobile. Further, since an LLC (long-acting coolant) aqueous solution containing an organic component flows as a coolant in the water-cooling medium flow path 25 of the battery device 1, high coolant corrosion resistance is required for the members (the bottom surface portion 10a of the battery pack 10 and the cooling structure 20) constituting the water-cooling medium flow path 25.
The battery device 1 includes a battery pack 10 that houses battery cells, not shown, and a cooling structure 20 that is provided outside (below) a bottom surface portion 10a of the battery pack 10. The battery pack 10 has a case portion and battery cells. The cross section of the case is substantially rectangular, and is divided into a bottom surface portion 10a, a side surface portion 10b, and an upper surface portion 10c. Of course, the structure of the battery pack 10 is not limited to this example.
The bottom surface 10a of the battery pack 10 is in direct contact with a water cooling medium flow path 25 described later. Therefore, the bottom surface portion 10a of the battery pack 10 is required to have corrosion resistance against the coolant (coolant corrosion resistance) in addition to external corrosion resistance. In the present embodiment, the bottom surface 10a of the battery pack 10 is made of a Zn-based plated steel sheet. The Zn-based plated steel sheet has high external corrosion resistance and high coolant corrosion resistance. Therefore, the bottom surface portion 10a of the battery pack 10 has high external corrosion resistance and coolant corrosion resistance. Details of the Zn-based plated steel sheet are described below.
The thickness of the Zn-based plated steel sheet constituting the bottom surface portion 10a of the battery pack 10 is not particularly limited, but is, for example, preferably 0.2 to 1.2mm, and more preferably 0.4 to 0.6mm. In this case, the bottom surface portion 10a can be formed thin while ensuring the strength of the bottom surface portion 10a of the battery pack 10. Therefore, the distance between the coolant and the internal structure of the battery pack 10 can be shortened, and therefore, the cooling efficiency of the battery pack 10 can be improved, and the cooling responsiveness of the battery pack 10 can be improved.
The materials of the side surface portion 10b and the upper surface portion 10c of the battery pack 10 are not particularly limited, but they are also preferably composed of a Zn-based plated steel sheet similar to the bottom surface portion 10a. In particular, since the side surface portion 10b is exposed to the external environment, it is preferably composed of a Zn-based plated steel sheet similar to the bottom surface portion 10a. The upper surface portion 10c and the side surface portion 10b are joined together with the sealant 10d interposed therebetween. The upper surface portion 10c is fixed to a bottom surface portion of the vehicle.
The cooling structure 20 is provided outside the bottom surface of the battery pack 10, and includes a plurality of flow path forming portions 21 and a plurality of joint portions 22. The flow channel forming portion 21 has a substantially rectangular cross section, and the interior thereof is a space. The space is also a water cooling medium flow path 25. The water cooling medium flow path 25 is in direct contact with the battery pack 10. Of course, the cross-sectional shape of the flow channel forming portion 21 is not limited to this example, and may be, for example, an arc shape as shown in fig. 4, a trapezoid shape as shown in fig. 5, or another shape. The water cooling medium flow path 25 extends in a direction perpendicular to the paper surface of fig. 1 (for example, a direction parallel to the longitudinal direction of the bottom surface portion 10a of the battery pack 10 or a direction perpendicular thereto), and is connected to a circulation path not shown. Of course, the extending direction of the water cooling medium flow path 25 is not limited to this example, and may be curved on the bottom surface portion 10a, for example. For example, the shape may be a U-shape in a plan view. The coolant flows through the circulation path and the water-cooling medium flow path 25. The coolant is cooled in the circulation path and then flows through the water-cooling medium flow path 25. The coolant absorbs heat from the battery pack 10 while flowing through the water-cooling medium flow path 25. After that, the coolant is again introduced into the circulation path. That is, the coolant repeatedly flows through the circulation path and the water cooling medium flow path 25, whereby the heat of the battery pack 10 is repeatedly absorbed.
Therefore, the cooling structure 20, which is a member constituting the water cooling medium flow path 25, is required to have not only the above-described external corrosion resistance but also the coolant corrosion resistance. In the present embodiment, the cooling structure 20 is formed of a Zn-based plated steel sheet. The Zn-based plated steel sheet has high external corrosion resistance and high coolant corrosion resistance. Therefore, the cooling structure 20 has high external corrosion resistance and coolant corrosion resistance. Further, the Zn-based plated steel sheet has a higher strength than an Al sheet having the same thickness. Here, the strength of the Zn-based plated steel sheet is, for example, tensile strength, and can be measured by a tensile test in accordance with the regulation of JIS Z2241. The Al plate has a high heat conductivity, but by forming the Zn-based plated steel sheet thinner, the same degree of heat conductivity as the Al plate can be achieved. Therefore, in the present embodiment, corrosion of the battery pack 10 and the cooling structure 20 due to the coolant can be suppressed, and therefore, a decrease in the heat conductivity and contamination (elution of components of the battery pack 10 or the cooling structure 20 into the coolant) that cause clogging can be suppressed.
The distance w between the widthwise ends of the water-cooling medium passages 25, in other words, the adjacent passage forming sections 21 is not particularly limited, but is preferably 40mm or less. In the example shown in fig. 1, since the cross-sectional shape of the flow channel forming portion 21 is substantially rectangular, the distance w between the width-direction end portions of the flow channel forming portion 21 may be in other words, the distance between the side portions 21b of the flow channel forming portion 21. In the example shown in fig. 4 and 5, the boundary portion between the flow channel forming portion 21 and the joint portion 22 becomes the width-direction end portion of the flow channel forming portion 21. This can expand the width of the water-cooling medium flow path 25, and thus can expand the contact area between the water-cooling medium flow path 25 and the bottom surface portion 10a, in other words, the contact area between the coolant and the battery pack 10. When the Zn-based plated steel sheet of the present embodiment is used, particularly high cooling efficiency can be obtained by setting the interval between the water-cooling medium passages 25 to 40mm or less. Therefore, in the present embodiment, the cooling efficiency of the battery pack 10 can be improved. The lower limit of the interval between the water-cooling medium passages 25 is not particularly limited, but is preferably 10mm or more. By setting the distance between the water cooling medium passages 25 to 10mm or more, joining by spot welding or mechanical joining means is enabled, and joining strength can be easily ensured.
Further, the ratio of the contact area of the water-cooling medium flow path 25 and the bottom surface portion 10a to the area of the bottom surface portion 10a is preferably 0.23 or more. This can enlarge the contact area between the coolant and the battery pack 10, and further, can improve the cooling efficiency of the battery pack 10. The upper limit value is not particularly limited, but may be about 0.80 since the joining strength between the joining portion 22 and the bottom surface portion 10a is preferably ensured to some extent. The above ratio is more preferably 0.23 to 0.71 from the viewpoint of balance between the bonding strength and the cooling efficiency. That is, the larger the ratio is, the more the cooling performance of the cooling structure 20 is improved, but on the other hand, the bonding strength with the battery pack 10 is preferably also considered. From such a viewpoint, the ratio is preferably 0.23 to 0.71.
The height of the water-cooling medium flow path 25, that is, the distance h in the thickness direction of the battery device 1 from the bottom surface portion 21a of the flow path forming portion 21 (the lower end portion 21a-1 of the flow path forming portion 21 in the example of fig. 4) to the joint portion 22 adjacent to the flow path forming portion 21 is not particularly limited, but is preferably about 0.9 to 25.0mm from the viewpoint of the cooling efficiency of the battery pack 10. On the other hand, the upper limit of the distance h is preferably 8.0mm from the viewpoint of workability for flow passage formation. That is, by setting the height of the water-cooling medium flow path 25 to about 0.9 to 8.0mm, both the cooling efficiency of the battery pack 10 and the workability for flow path formation can be achieved.
The joining portion 22 is a member for joining the cooling structure 20 to the battery pack 10, and is joined to the battery pack 10 via the spot welding portion 30. Of course, the method of joining the joining portion 22 to the battery pack 10 is not limited to this example. For example, the engaging portion 22 may be engaged with the battery pack 10 by an engaging member such as a mechanical engagement or a screw. Further, as shown in fig. 1, a sealant 35 may be used for the purpose of protecting the joint and improving the sealing property. The sealant 35 may be used as an adhesive (i.e., as an adhesive between the joint 22 and the battery pack 10). Here, examples of the mechanical joining means (mechanical joining) includeTOX (registered trademark) manufactured by presotechnik corporation, and the like. The sealant is a substance containing a resin as a main component, and is an organic substance coated with a resin as a main component, which is coated to prevent penetration of a liquid (cooling liquid in the present invention) such as water into a gap or leakage from a gap, and is also called a sealant or the like. Commercially available materials as sealants or sealants may be used. Further, an adhesive may be used if it has a sealing function. The use of an adhesive is more preferable because the strength of the joint portion increases. In the case of using a sealant having adhesiveness such as an adhesive, the bonding strength can be ensured without performing spot welding or mechanical bonding, and therefore, the present invention can be applied without performing spot welding or mechanical bonding. In particular, mechanical joining is preferable because of the high resistance during welding and poor spot weldability depending on the type of plating of the steel sheet constituting the battery pack 10 and the type of coating on the surface. Further, the joint structure of the battery pack 10 and the cooling structure 20 is preferably sealed A composite joint structure of sealing glue and spot welding or sealing glue and mechanical joint. This can improve the air tightness of the water cooling medium flow path 25 and improve the bonding strength between the battery pack 10 and the cooling structure 20. In the examples shown in fig. 1, 4, and 5, the joint structure of the battery pack 10 and the cooling structure 20 becomes a composite joint structure of sealant and spot welding.
The cooling structure 20 is manufactured by, for example, processing (for example, bending, deep drawing, and the like) 1 Zn-based plated steel sheet. Therefore, the cooling structure 20 can be manufactured inexpensively and easily. That is, by forming the cooling structure 20 from a Zn-based plated steel sheet, the cooling structure 20 can be manufactured with higher productivity than in the case of forming the cooling structure of the battery pack by die casting, or the like as in the conventional case. The thickness of the Zn-coated steel sheet constituting the cooling structure 20 is not particularly limited, but is preferably, for example, 0.4 to 2.0mm, and more preferably 0.5 to 1.0mm. In this case, the strength of the cooling structure 20 can be improved, and the workability of the cooling structure 20 (workability in manufacturing the cooling structure 20) can be improved. Of course, the manufacturing method of the cooling structure 20 is not limited to this example. For example, the cooling structure 20 may be manufactured using different Zn-based plated steel sheets for each water cooling medium flow path 25. In this example, the Zn-based plated steel sheets may be joined to the battery pack 10 by forming the flow path forming portions 21 corresponding to the water cooling medium flow paths 25 by processing (for example, bending, deep drawing, or the like) the Zn-based plated steel sheets.
As described above, in the present embodiment, the Zn-based plated steel sheet excellent in external corrosion resistance and coolant corrosion resistance is configured to constitute the bottom surface portion 10a of the battery pack 10 and the cooling structure 20 exposed to the external environment and the coolant, and therefore, the external corrosion resistance and the coolant corrosion resistance of the battery device 1 can be improved.
Fig. 2 and 3 show other examples of the battery device 1. In the example shown in fig. 2, a flow path upper cover 26 is disposed between the cooling structure 20 and the battery pack 10. The flow path upper cover 26 is made of a Zn-based plated steel sheet. In the example of fig. 3, a filler 40 is further disposed between the flow path cover 26 and the battery pack 10. In fig. 2 and 3, the flow path cover 26 and the caulking agent 40 are drawn separately from other members in order to clarify the positional relationship between the members, but in reality, the flow path cover 26, the caulking agent 40, and the other members are joined to each other. For some reason (errors in dimensional accuracy, complex irregularities formed on the surface of the bottom surface portion 10a of the battery device 1, etc.), it may be difficult to join the bottom surface portion 10a and the cooling structure 20 (here, the flow path upper cover 26) without a gap. In that case, the structure shown in fig. 3 may be employed. The gap filler 40 is generally a substance in which a pigment having high thermal conductivity is contained in a resin, and the heat exchange efficiency can be improved by inserting the gap filler 40 between different substances. In the present embodiment, the thermal conductivity of the caulking agent 40 is preferably 3.5W/m or more, and examples of the caulking agent 40 include "SDP-3540-A" manufactured by Shin-Etsu Silicone Co. The thickness of the caulking agent is preferably 0.1mm to 8.0mm, more preferably 0.5mm to 3.0mm. When the battery pack 10 and the cooling structure 20 are connected as described above, if gaps are generated between them due to variations in dimensional accuracy, the gaps can be filled with a heat-conductive filler 40 or the like to improve heat exchange performance. However, the heat conductivity of the filler 40 is preferably lower than that of a Zn-coated steel sheet, and is preferably 0.5mm to 3.0mm in order to fill gaps caused by variations in dimensional accuracy of the members.
In the example of fig. 2 and 3, the bottom surface portion 10a may not necessarily be made of the above-described metal material. This is because the bottom surface portion 10a is not in contact with the coolant.
<2 > constitution of Zn-based plated steel sheet >
Next, an example of a Zn-based plated steel sheet constituting the battery pack 10 and the flow path forming portion 21 will be described in detail.
The Zn-based plated steel sheet is a steel sheet having a plating layer containing Zn formed thereon. The plating layer may be formed on only one surface of the steel sheet, but is preferably formed on both surfaces. Examples of the Zn-based plated steel sheet include zinc-plated steel sheet, zinc-nickel-plated steel sheet, zinc-iron-plated steel sheet, zinc-chromium-plated steel sheet, zinc-aluminum-plated steel sheet, zinc-titanium-plated steel sheet, zinc-magnesium-plated steel sheet, zinc-manganese-plated steel sheet, zinc-aluminum (Al) -magnesium (Mg) -plated steel sheet, and zinc-aluminum-magnesium-silicon-plated steel sheet. Further, a Zn-based plated steel sheet containing a small amount of a dissimilar metal element or impurity such as cobalt, molybdenum, tungsten, nickel, titanium, chromium, aluminum, manganese, iron, magnesium, lead, bismuth, antimony, tin, copper, cadmium, arsenic, or the like in these plating layers, or a Zn-based plated steel sheet in which an inorganic substance such as silica, alumina, titania, or the like is dispersed may be used. Further, the plating described above may be combined with other types of plating, and for example, a multilayer plating combined with iron plating, iron-phosphorus plating, nickel plating, cobalt plating, or the like may be applied. The plating method is not particularly limited, and may be any of known plating methods, hot dip plating methods, vapor deposition methods, dispersion plating methods, vacuum plating methods, and the like.
Further, an inorganic film or a resin film is formed as a chemical conversion treatment film on the surface (only one surface, but preferably both surfaces) of the Zn-based plated steel sheet. The inorganic film contains a Si-based component or a Zr-based component as a main component (for example, 50 mass% or more based on mass%). The inorganic coating may contain an organic component.
The inorganic film or the resin film preferably has conductivity. In this case, the weldability and electrodeposition coatability of the Zn-based plated steel sheet can be improved. Further, the inorganic coating film is preferably composed of a compound phase containing 1 or more of Si-O bonds, si-C bonds, and Si-OH bonds. The compound phase preferably contains an acrylic resin described later. When these requirements are satisfied, the adhesion of the chemical conversion coating film can be improved, and therefore the external corrosion resistance and the coolant corrosion resistance of the processed portion of the Zn-based plated steel sheet can be improved. The inorganic coating preferably contains at least 1 or more of a V component, a P component, and a Co component as a rust-preventive component. The rust preventive component of the inorganic coating film is preferably one or more of vanadium oxide, phosphoric acid and Co nitrate. The thickness of the inorganic coating film is preferably more than 0 μm and 1.5 μm or less. In this case, the conductivity or adhesion of the chemical conversion coating film can be further improved.
The resin film preferably contains a resin, an anticorrosive pigment, and a conductive pigment. Further, the resin film preferably contains metal particles and an intermetallic compoundAny one or more of the particles, conductive oxide particles and conductive non-oxide ceramic particles is used as a conductive pigment, and the powder resistivity of the conductive pigment at 25 ℃ is 185 multiplied by 10 -6 Ω cm or less, and contains any one or more selected from the group consisting of Zn, si, zr, V, cr, mo, mn, fe and W as constituent elements. Further, the resin film preferably contains the conductive pigment in a proportion of 1.0 mass% or more and 30 mass% or less. Further, the average thickness of the resin film is preferably 1.0 μm or more and 15 μm or less. Further, the average particle diameter of the conductive pigment is preferably 0.5 to 1.5 times the average thickness of the resin film. When any one of 1 or more of these requirements is satisfied, the external corrosion resistance and the coolant corrosion resistance of the Zn-based plated steel sheet can be further improved.
Examples of the chemical conversion coating include, for example, japanese patent application laid-open No. 4776458, japanese patent application laid-open No. 5336002, japanese patent application laid-open No. 6191806, japanese patent application laid-open No. 6263278, international publication No. 2020/202461, japanese patent application laid-open No. 4084702, and the like. Therefore, the chemical conversion coating film described in these publications can be suitably used as the chemical conversion coating film of the present embodiment. Thus, an outline of the chemical conversion coating will be described.
The 1 st example of the chemical conversion coating is an inorganic coating, and is a chemical conversion coating containing an organosilicon compound (silane coupling agent) as a main component. The organosilicon compound is obtained by blending a silane coupling agent (A) having 1 amino group in the molecule and a silane coupling agent (B) having 1 glycidyl group in the molecule in a solid content mass ratio of 0.5 to 1.7. The organosilicon compound contains more than 2-SiR in the molecule 1 R 2 R 3 (wherein R is 1 、R 2 R is R 3 Independently of each other, at least 1 represents an alkoxy group or a hydroxyl group, at least 1 represents a functional group (a) represented by an alkoxy group, and at least 1 hydrophilic functional group (b) selected from the group consisting of a hydroxyl group (another hydroxyl group other than the hydroxyl group which may be contained in the functional group (a)) and an amino group, and has an average molecular weight of 1000 to 10000.
In example 1, the Zr-based component is contained as fluorozirconic acid in the chemical conversion coating film. The chemical conversion coating film contains at least 1 of a vanadium compound as the V component, phosphoric acid as the P component, and cobalt as the Co component, and is selected from the group consisting of cobalt sulfate, cobalt nitrate, and cobalt carbonate. As the vanadium compound, for example, vanadium pentoxide V can be exemplified 2 O 5 HVO of metavanadate 3 Ammonium metavanadate, sodium metavanadate, vanadium trichloride VOCl 3 Vanadium trioxide V 2 O 3 Vanadium dioxide VO 2 Vanadium oxide, vanadyl sulfate VOSO 4 Vanadyl acetylacetonate VO (OC (=ch) 2 )CH 2 COCH 3 )) 2 Vanadium acetylacetonate V (OC (=ch) 2 )CH 2 COCH 3 )) 3 Vanadium trichloride VCl 3 And phosphovanadium molybdic acid. Further, a vanadium compound obtained by reducing a 5-valent vanadium compound to a 4-valent to 2-valent vanadium compound with an organic compound having at least 1 functional group selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, a primary to tertiary amino group, an amide group, a phosphate group, and a phosphonate group may be used.
The 2 nd example of the chemical conversion coating is an inorganic coating, and is a chemical conversion coating containing an organosilicon compound (silane coupling agent) as a main component. The organosilicon compound has a cyclic siloxane structure in its structure. The term "cyclic siloxane bond" as used herein means a cyclic structure having a structure in which Si-O-Si bonds are continuous and composed of only Si and O bonds, and having a Si-O repetition number of 3 to 8.
The organosilicon compound is obtained by blending a silane coupling agent (A) having at least 1 amino group in the molecule and a silane coupling agent (B) having at least 1 glycidyl group in the molecule in a ratio of 0.5 to 1.7 in terms of the mass ratio of solid components [ (A)/(B) ]. The organosilicon compound (W) thus obtained contains more than 2 SiRs in the molecule 1 R 2 R 3 (wherein R is 1 、R 2 R is R 3 Independently of one another, represents alkoxy or hydroxy, R 1 、R 2 R is R 3 At least 1 of the functional groups (a) represents an alkoxy group, and at least 1 is selected from the group consisting of hydroxyl groups (wherein the functional groups (a) contain hydroxyl groupsA hydroxyl group other than the hydroxyl group) and at least 1 hydrophilic functional group (b) of the group consisting of an amino group, and the average molecular weight is preferably 1000 to 10000.
In example 2, the Zr-based component is contained as a zirconium compound in the chemical conversion coating film. Examples of the zirconium compound include fluorozirconic acid, ammonium zirconium fluoride, zirconium sulfate, zirconium oxychloride, zirconium nitrate, and zirconium acetate. The zirconium compounds are more preferably fluorozirconic acid among them. When fluorozirconic acid is used, more excellent corrosion resistance and coatability can be obtained.
The V component is a vanadium compound, the P component is a phosphoric acid compound, and the Co component is at least 1 selected from the group consisting of cobalt sulfate, cobalt nitrate, and cobalt carbonate. As the vanadium compound, for example, vanadium pentoxide V can be exemplified 2 O 5 HVO of metavanadate 3 Ammonium metavanadate, sodium metavanadate, vanadium trichloride VOCl 3 Vanadium trioxide V 2 O 3 Vanadium dioxide VO 2 Vanadium oxide, vanadyl sulfate VOSO 4 Vanadyl acetylacetonate VO (OC (=ch) 2 )CH 2 COCH 3 ) 2 Vanadium acetylacetonate V (OC (=ch) 2 )CH 2 COCH 3 ) 3 Vanadium trichloride VCl 3 And phosphovanadium molybdic acid. Further, a vanadium compound obtained by reducing a vanadium compound having 5 valence to 4 valence to 2 valence with an organic compound having at least 1 functional group selected from the group consisting of hydroxyl group, carbonyl group, carboxyl group, primary to tertiary amino group, amide group, phosphate group and phosphonate group may also be used.
Examples of the phosphoric acid compound include phosphoric acid, ammonium phosphate, potassium phosphate, sodium phosphate, and the like. The phosphoric acid compound is more preferably phosphoric acid among them. In the case of using phosphoric acid, more excellent corrosion resistance can be obtained.
The 3 rd example of the chemical conversion coating is an example of an inorganic coating, and includes acrylic resin, zirconium, vanadium, phosphorus, and cobalt. More specifically, the chemical conversion coating film includes a particulate acrylic resin (resin particles) and an inhibitor phase. The acrylic resin is preferably a resin containing a polymer of an alkyl (meth) acrylate, and may be a polymer obtained by polymerizing only an alkyl (meth) acrylate, or may be a copolymer obtained by polymerizing an alkyl (meth) acrylate with the other monomer. "(meth) acrylic" means "acrylic" or "methacrylic". The inhibitor phase comprises zirconium, vanadium, phosphorus and cobalt. Zirconium forms a crosslinked structure with the acrylic resin.
The 4 th example of the chemical conversion treatment film is an example of an inorganic film, and includes a zirconium carbonate compound, an acrylic resin, a vanadium compound, a phosphorus compound, and a cobalt compound. Examples of the zirconium carbonate compound include zirconium carbonate, zirconium ammonium carbonate, zirconium potassium carbonate, and zirconium sodium carbonate, and 1 or more of these compounds can be used. Among them, zirconium carbonate and ammonium zirconium carbonate are preferable in view of excellent corrosion resistance.
The acrylic resin is a resin obtained by copolymerizing monomer components including at least styrene (b 1), (meth) acrylic acid (b 2), (meth) acrylic acid alkyl ester (b 3) and acrylonitrile (d 4), wherein the amount of acrylonitrile (b 4) is 20 to 38 mass% based on the solid content mass of all monomer components of the resin, and the acrylic resin is a water-soluble resin and an aqueous latex resin having a glass transition temperature of-12 to 15 ℃. That is, the acrylic resin exists in the form of resin particles in the chemical conversion coating film.
Examples of the vanadium compound include 2 to 4-valent vanadium compounds, more specifically, vanadium pentoxide (V 2 O 5 ) Metavanadate (HVO) 3 ) Ammonium metavanadate, sodium metavanadate, vanadium oxychloride (VOCl) 3 ) Vanadium compound obtained by reducing 5-valent vanadium compound to 2-4-valent vanadium compound with reducing agent, vanadium trioxide (V 2 O 3 ) Vanadium dioxide (VO) 2 ) Vanadyl sulfate (VOSO) 4 ) Vanadyl oxalate [ VO (COO) 2 ]Vanadyl acetylacetonate [ VO (OC (CH) 3 )＝CHCOCH 3 )) 2 ]Vanadium acetylacetonate [ V (OC (CH) 3 )＝CHCOCH 3 )) 3 ]Vanadium trichloride (VCl) 3 ) Phosphovanadic acid { H 15-X [PV 12-x Mo x O 40 ]·nH 2 O (6 < x < 12, n < 30) } vanadium sulfate(VSO 4 ·8H 2 O), vanadium dichloride (VCl 2 ) Vanadium compounds having an oxidation number of 4 to 2 such as Vanadium Oxide (VO).
Examples of the phosphorus compound include inorganic acid anions having a phosphorus-containing acid group and organic acid anions having a phosphorus-containing acid group. Examples of the inorganic acid radical anion having a phosphate group include inorganic acid radical anions having at least 1 hydrogen free inorganic acids such as orthophosphoric acid, metaphosphoric acid, condensed phosphoric acid, pyrophosphoric acid, triphosphoric acid, tetraphosphoric acid, and hexametaphosphoric acid, and salts thereof.
Examples of the organic acid anion having a phosphorus-containing acid group include 1-hydroxymethane-1, 1-diphosphonic acid, 1-hydroxyethane-1, 1-diphosphonic acid, 1-hydroxypropane-1, 1-diphosphonic acid, 1-hydroxyethylene-1, 1-diphosphonic acid, 2-hydroxyphosphonoacetic acid, aminotri (methylenephosphonic acid), ethylenediamine-N, N, N ', at least 1 hydrogen-free organic acid anion such as N' -tetrakis (methylenephosphonic acid), hexamethylenediamine-N, N, N ', N' -tetrakis (methylenephosphonic acid), diethylenetriamine-N, N, N ', N' -penta (methylenephosphonic acid), 2-phosphonobutane-1, 2, 4-tricarboxylic acid, organic phosphonic acids such as phytic acid, organic phosphoric acid, and salts thereof.
Examples of the cobalt compound include cobalt sulfate, cobalt nitrate, and cobalt carbonate.
The 5 th example of the chemical conversion treatment film is an example of a resin film, and contains any one or more of metal particles, intermetallic compound particles, conductive oxide particles, and conductive non-oxide ceramic particles as a conductive pigment. The powder resistivity of the conductive pigment at 25 ℃ is 185 multiplied by 10 -6 Ω cm or less, and contains any one or more selected from the group consisting of Zn, si, zr, V, cr, mo, mn, fe and W as constituent elements.
Examples of the intermetallic compound include ferrosilicon and ferromanganese. As the conductive oxide particles, for example, a substance having conductivity by doping impurities into a crystal lattice of an oxide (doped conductive oxide) or a substance having an oxide surface modified with a conductive substance can be used. As the former, it is possible toGenerally known metal oxides doped with at least 1 metal element selected from Al, nb, ga, sn (for example, al-doped zinc oxide, nb-doped zinc oxide, ga-doped zinc oxide, sn-doped zinc oxide, etc.) and the like are used. As the latter, snO having conductivity to oxide can be used 2 The modified zinc oxide, silica, and other generally known substances. As the conductive oxide, a doped conductive oxide is preferable, and as the doped conductive oxide, al doped zinc oxide is preferable.
The conductive non-oxide ceramic particles are composed of ceramics formed of an element or a compound that does not contain oxygen. Examples of the conductive non-oxide ceramic particles include boride ceramic, carbide ceramic, nitride ceramic, and silicide ceramic. The boride ceramic, carbide ceramic, nitride ceramic, and silicide ceramic are non-oxide ceramics containing boron B, carbon C, nitrogen N, and silicon Si as main non-metal constituent elements, respectively, and any one or more ceramics selected from the group consisting of Zn, si, zr, V, cr, mo, mn and W may be used as these commonly known non-oxide ceramics. Further, the non-oxide ceramic particles are more preferably the non-oxide ceramics exemplified below from the viewpoints of the presence or absence of industrial products, stable fluidity in the market at home and abroad, price, resistivity, and the like. For example, mo is more preferable 2 B、MoB、MoB 2 、Mo 2 B 5 、NbB 2 、VB、VB 2 、W 2 B 5 、ZrB 2 、Mo 2 C、V 2 C、VC、WC、W 2 C、ZrC、Mo 2 N、VN、ZrN、Mo 3 Si、Mo 5 Si 3 、MoSi 2 、NbSi 2 、Ni 2 Si、Ta 2 Si、TaSi 2 、TiSi、TiSi 2 、V 5 Si 3 、VSi 2 、W 3 Si、WSi 2 、ZrSi、ZrSi 2 、CrB、CrB 2 、Cr 3 C 2 、Cr 2 N, crSi, particles of a mixture of 2 or more kinds thereof.
The 6 th example of the chemical conversion coating film is an example of a resin coating film, and includes a resin having a urethane bond and conductive particles (conductive pigment). The resin having a urethane bond is an organic resin obtained from a film-forming resin raw material comprising (1) a polyester polyol having a functional group number of at least 3, (2) a blocked compound of an organic polyisocyanate or a blocked compound of a prepolymer having an NCO group at the end obtained by reacting an organic polyisocyanate with an active hydrogen compound.
(1) The polyester polyol having a functional group number of at least 3 can be obtained by esterifying a dicarboxylic acid, a diol, and a polyol having at least 3 OH groups.
Examples of dicarboxylic acids used for producing the polyester polyol include aliphatic dicarboxylic acids such as succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, maleic anhydride, fumaric acid, itaconic acid, and dimer acid, and aromatic and alicyclic dicarboxylic acids such as phthalic acid, phthalic anhydride, isophthalic acid, dimethyl isophthalate, terephthalic acid, dimethyl terephthalate, 2, 6-naphthalene dicarboxylic acid, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, cyclohexane dicarboxylic acid, dimethyl cyclohexanedicarboxylate, methylhexahydrophthalic anhydride, nadic anhydride, and methylnadic anhydride.
Examples of the diol include aliphatic diols such as ethylene glycol, diethylene glycol, propylene glycol, 1, 3-butanediol, 1, 4-butanediol, dipropylene glycol, 1, 5-pentanediol, 1, 6-hexanediol, neopentyl glycol ester of hydroxypivalic acid, triethylene glycol, 1, 9-nonanediol, 3-methyl-1, 5-pentanediol, 2, 4-trimethyl-1, 3-pentanediol, 2-ethyl-1, 3-hexanediol, 2, 4-diethyl-1, 5-pentanediol, polycaprolactone diol, polypropylene glycol, polytetramethylene ether glycol, polycarbonate diol, 2-n-butyl-2-ethyl-1, 3-propanediol, 2-diethyl-1, 3-propanediol, and aromatic diols such as cyclohexane dimethanol, 2-methyl-1, 1-cyclohexanedimethanol, dihydroxyethyl terephthalate, 1, 4-bis (2-hydroxyethoxy) benzene, hydrogenated bisphenol A, ethylene oxide A, bisphenol A adduct, and bisphenol A adduct.
Examples of the polyhydric alcohol having at least 3 OH groups include glycerin, trimethylolpropane, trimethylolethane, 1,2, 6-hexanetriol, pentaerythritol, diglycerin, and ethylene oxide adducts, propylene oxide adducts, and epsilon-caprolactone adducts using these polyhydric alcohols as an initiator.
As the end-capping compound of (2), examples thereof include compounds having at least 2 NCO groups, such as trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1, 2-propylene diisocyanate, 2, 3-butylene diisocyanate, 1, 3-butylene diisocyanate, 2, 4-or 2, 4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate, and aliphatic diisocyanates such as methyl caproate 2, 6-diisocyanate, for example, 1, 3-cyclopentane diisocyanate, 1, 4-cyclohexane diisocyanate, 1, 3-cyclohexane diisocyanate, 3-isocyanatomethyl-3, 5-trimethylhexyl isocyanate, 4' -methylenebis (cyclohexyl isocyanate) aromatic diisocyanates such as methyl-2, 4-cyclohexane diisocyanate, methyl-2, 6-cyclohexane diisocyanate, 1, 2-bis (isocyanatomethyl) cyclohexane, 1, 4-bis (isocyanatomethyl) cyclohexane, 1, 3-bis (isocyanatomethyl) cyclohexane, trans-cyclohexane-1, 4-diisocyanate and the like, for example, m-xylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4' -diphenyl diisocyanate, 1, 5-naphthalene diisocyanate, 4' -diphenylmethane diisocyanate, 2, 4-or 2, 6-toluene diisocyanate, 4' -toluidine diisocyanate, dianisidine diisocyanate, 4' -diphenyl ether diisocyanate and the like, for example, aromatic aliphatic diisocyanates such as ω, ω '-diisocyanate-1, 3-dimethylbenzene, ω' -diisocyanate-1, 4-diethylbenzene, α, α, α ', α' -tetramethyl-m-xylylene diisocyanate, triisocyanates such as triphenylmethane-4, 4',4 "-triisocyanate, 1,3, 5-triisocyanatobenzene, 2,4, 6-triisocyanatotoluene, ω -isocyanatoethyl-2, 6-diisocyanatocaproate, blocked compounds of tetraisocyanates such as 4,4' -diphenylmethane-2, 2', 5' -tetraisocyanate, dimers, trimers, biuret, allophanate, carbodiimide, polymethylene polyphenyl polyisocyanate (crude MDI, c-MDI, polymeric MDI), crude TDI and the like, blocked compounds of derivatives of isocyanate compounds, or blocked compounds of prepolymers having an NCO group at the end obtained by reacting them with an active hydrogen compound.
The conductive particles are particles having corrosion resistance, which are alloys or compounds containing 50 mass% or more of Si, or a composite of these. The conductive particles are preferably ferrosilicon. In addition, an anticorrosive pigment may be added to the chemical conversion coating film. Examples of the rust inhibitive pigment include known rust inhibitive pigments such as 6-valent chromates such as strontium chromate and calcium chromate. In the case where it is desired to avoid the use of a 6-valent chromium compound as an anti-rust agent, one or more species selected from silicate ion, phosphate ion, and vanadate ion may be used.
Of course, examples of the chemical conversion coating film of the present embodiment are not limited to the above, and for example, the chemical conversion coating film exemplified in examples described below may be suitably used.
The method for forming the chemical conversion coating is not particularly limited, and the chemical conversion coating (coating treatment liquid) corresponding to each composition may be applied to a Zn-based plated steel sheet by a known method and baked and dried. As an example of a preferable combination of a Zn-based plated steel sheet and a chemical conversion coating film, a combination of a Zn-Al-Mg plated steel sheet and an inorganic coating film containing a Si-based component as a main component is given. Further, as another example, a combination of a zn—al plated steel sheet and a resin film is given.
Examples
The present invention will be described in further detail with reference to examples. The embodiment described below is only an example of the present invention, and does not limit the present invention.
< preparation of Material >
As an extremely low carbon steel excellent in workability, steel having the steel components shown in table 1 (the remainder being iron and impurities) was hot rolled, and a cold rolled steel sheet having a sheet thickness set to 0.6mm was prepared by pickling and cold rolling.
TABLE 1
Further, a hot dip galvanized steel sheet was prepared by annealing the cold rolled steel sheet with an annealed continuous hot dip plating apparatus under a condition that the sheet temperature reached at most 820 ℃. Here, the gas atmosphere in the annealing furnace in the annealing step was set to contain 1.0% by volume of H 2 N of (2) 2 An atmosphere. As components of the plating bath in the plating step, 4 kinds of Zn-0.2 mass% Al (hereinafter also referred to as "GI"), zn-0.09 mass% Al (hereinafter also referred to as "GA"), zn-6 mass% Al-3 mass% Mg (hereinafter also referred to as "Zn-Al-Mg"), zn-11 mass% Al-3 mass% Mg-0.2 mass% Si (hereinafter also referred to as "Zn-Al-Mg-Si") were used.
In hot dip galvanization using a hot dip plating bath of Zn-0.09 mass% Al plating (GA), alloying hot dip galvanization is performed by the following steps. That is, the steel sheet is immersed in a hot dip plating bath. Then, while the steel sheet is lifted from the plating bath, N is blown from the slit nozzle 2 The amount of adhesion is adjusted by wiping the gas. Then, the steel sheet was alloyed by heating at a plate temperature of 480 ℃ using an induction heater, and Fe in the steel sheet was diffused into the plating layer.
Furthermore, the amount of deposit of the plated layer of the plated steel sheet was set to 45g/m for each surface GA of the steel sheet 2 The plating layer other than GA was set to 60g/m 2 . For comparison, a cold-rolled steel sheet which was annealed only in a continuous annealing line without plating was also prepared.
Next, the surface of the plated steel sheet produced by the above-described steps is coated with a chemical conversion treatment liquid (coating treatment liquid) by a roll coater as needed. The amount of the chemical conversion treatment liquid (i.e., the film thickness of the chemical conversion treatment film) is controlled by adjusting the rotation speed of the roll coater and the pressure between rolls (generally referred to as the nip pressure). Thus, a chemical conversion coating film having a predetermined thickness is formed on the plated steel sheet.
Here, when the chemical conversion coating film is an inorganic coating film, the chemical conversion coating liquid is applied and then dried by a hot blast stove under a condition that the plate temperature reaches 80 ℃. When the chemical conversion coating film is a resin coating film, the chemical conversion treatment paleat E200 manufactured by Nihon Parkerizing is applied to the plated steel sheet by a roll coater as a pretreatment for improving the adhesion to the plated steel sheet before the chemical conversion treatment liquid is applied to the plated steel sheet, and dried by a hot blast furnace under a condition that the sheet temperature reaches 80 ℃. Thereafter, the chemical conversion treatment liquid was coated with a predetermined film thickness by a roll coater, and then dried by a hot blast furnace under conditions such that the plate temperature became 200 ℃. Chemical conversion treatment films are applied to both sides of the plated steel sheet. The film thickness after various films were coated and dried was measured by observing a sample obtained by embedding the coated steel sheet in a resin so that a vertical cross section could be observed and grinding the steel sheet with a scanning electron microscope. The observation magnification by a scanning electron microscope is suitably selected and carried out by selecting an optimum magnification according to the film thickness of the coating film.
In the sample prepared by coating and drying the inorganic film with a film thickness exceeding 1.5 μm, cracks, film detachment, and the like occur in the film in any of the treatment liquids, and a film obtained by uniformly forming a film cannot be obtained, so that the inorganic film with a film thickness exceeding 1.5 μm is judged to be difficult to manufacture. Details of steel sheets produced by coating films on various plated steel sheets are shown in tables 5A to 5E.
< method for producing inorganic chemical conversion treatment liquid >
An inorganic chemical conversion treatment liquid (chemical conversion treatment liquid for forming an inorganic coating film) was prepared by the following steps. Specifically, an aqueous solution containing 10g/L of gamma-aminopropyl triethoxysilane was prepared as an inorganic chemical conversion treatment solution containing Si as a main component. Further, 1.3g/L of vanadium oxide, 0.7g/L of phosphoric acid, and 0.5g/L of Co nitrate were added to the prepared aqueous gamma-aminopropyl triethoxysilane solution, respectively, as required, to prepare an inorganic chemical conversion treatment solution.
Further, as an inorganic chemical conversion treatment liquid containing Zr-based components as a main component, an aqueous solution containing 3.0g/L of ammonium zirconium carbonate was prepared. Further, 1.3g/L of vanadium oxide, 0.7g/L of phosphoric acid, and 0.5g/L of Co nitrate were added to the obtained ammonium zirconium carbonate aqueous solution, as required, to prepare an inorganic chemical conversion treatment solution. Details of the inorganic chemical conversion treating liquid thus produced are shown in table 2.
Whether or not an si—o bond is included in the inorganic film is confirmed by the following method. That is, the produced inorganic chemical conversion treatment solution was coated on any one of the plated steel sheets produced in the above manner using a coil rod, and dried under a condition that the sheet temperature reached 80 ℃. Thereby, an inorganic coating film is formed on the plated steel sheet. Next, IRT-5200, manufactured by japan spectroscopic corporation, was used to measure the film surface, and from the attribution of the observed peaks of the resin component sources in the infrared absorption spectrum of the obtained inorganic film, it was determined whether or not the inorganic film contained 1 or more of si—o bonds, si—c bonds, and si—oh bonds, respectively. Specifically, at 3250cm -1 Near 1080 cm to 1020cm -1 Near 500-300 cm -1 Near, 900-700 cm -1 When a peak is observed at least at any position in the vicinity, it is determined that the inorganic film contains any one or more of Si-O bonds, si-C bonds, and Si-OH bonds. The determination results are shown in table 2.
< method for producing resin-based chemical conversion treatment liquid >
A resin-based chemical conversion treatment liquid (chemical conversion treatment liquid for forming a resin film) was prepared by the following steps. Specifically, as the polyester resin, a solution obtained by dissolving 30 mass% of "VYLON (R) 300" manufactured by eastern spinning corporation in cyclohexanone as a solvent was prepared, and 20 parts by mass of melamine resin "CYMEL (R) 303" manufactured by Allnex corporation was added to 100 parts by mass of the solid content of the solution and mixed. Further, 5 mass% of a curing catalyst "CYCAT (R) 600" manufactured by Allnex corporation was added to the total solid content of the obtained mixed solution, and mixed. Thus, a base treatment liquid for obtaining a resin film was prepared.
Next, the following particles were mixed with the prepared base treatment liquid to prepare a resin-based chemical conversion treatment liquid. The amount of particles added was adjusted by the following method. That is, the mass ratio of the particles added to the base treatment liquid to the resin film (mass ratio relative to the solid components other than the particles) was obtained, and the volume ratio was calculated from the specific gravity of the solid components of the resin film and the specific gravity of the particles. Next, the amount of particles added was adjusted so that the calculated volume ratio became the volume ratio described in table 3. The specific gravity is a commodity catalog value or a literature value of each substance. Details of the resin-based treatment liquid are shown in table 3.
TABLE 3 Table 3
Vanadium boride: VB manufactured by Japanese New Metal Co Ltd 2 O' is classified by a sieve to give a substance having an average particle diameter of 3.1. Mu.m. Hereinafter, also referred to as "VB2". The average particle diameter is calculated based on mass% of each particle size division of the classification.
Al doped zinc oxide: the conductive zinc oxide (Al-Doped ZnO) "23-K" from the company HAKUSUI TECH was used, and the primary particle size was 120 to 250nm (catalogue value). Hereinafter also referred to as "Al-ZnO".
Metallic zinc: the zinc particles of the reagent were classified by a sieve to have an average particle diameter of 10. Mu.m. Hereinafter also referred to as "Zn".
Ferrosilicon: a material having an average particle diameter of 3.5 μm was used, which was obtained by pulverizing ferrosilicon manufactured by MARUBENI TETSUGEN company into fine particles by a pulverizer and classifying the fine particles by a sieve. Hereinafter also referred to as "Fe-Si".
Ferromanganese: a material having an average particle diameter of 3.5 μm was used, which was obtained by pulverizing ferrosilicon manufactured by MARUBENI TETSUGEN company into fine particles by a pulverizer and classifying the fine particles by a sieve. Hereinafter also referred to as "Fe-Mn".
Zirconium boride: zrB manufactured by Japanese New Metal Co Ltd 2 O' is classified by a sieve to give a substance having an average particle diameter of 2. Mu.m. Hereinafter also referred to as "ZrB2".
Molybdenum silicide: use of "MoSi made by Nippon New Metal Co Ltd 2 F' A substance having an average particle diameter of 3.5 μm was classified by a sieve. Hereinafter also referred to as "MoSi2".
Chromium boride: use of "CrB" manufactured by Japanese New Metal Co Ltd 2 O' is classified by a sieve to give a substance having an average particle diameter of 5. Mu.m. Hereinafter also referred to as "CrB2".
Tungsten silicide: use of "B" manufactured by Japanese New Metal Co Ltd 2 O' is classified by a sieve to give a substance having an average particle diameter of 2. Mu.m. Hereinafter also referred to as "WSi2".
Nickel: the nickel powder of the reagent was classified by a sieve to have an average particle diameter of 5. Mu.m. Hereinafter also referred to as "Ni".
Conductive titanium oxide: the Sn-doped titanium oxide "ET-500W" manufactured by Shi Yuan Co., ltd was used to have an average particle diameter of 2 to 3 μm (catalogue value). Hereinafter also referred to as "conductive Ti".
Alumina: the fine alumina "A-42-2" produced by Showa electric company had an average particle diameter (particle size distribution center diameter) of 4.7. Mu.m. Hereinafter also referred to as "alumina".
Titanium oxide: using TIPAQUE manufactured by Shi Yuan industries Co (R) CR-95', average particle size 0.28 μm (catalogue value). Hereinafter also referred to as "TiO2".
Aluminum nitride: aluminum nitride powder for filler, manufactured by Tokuyama corporation, and having a particle size of 1 μm (commercial catalog value) were used. Hereinafter also referred to as "AlN".
The powder resistivity of the particles in table 3 was obtained as a resistance value when each powder was compressed at 25 ℃ under 10MPa using a powder bulk resistance measurement system MCP-PD51 type of Mitsubishi Chemical Analytech company.
< evaluation of the produced Metal sheet >
(0. Evaluation of Strength)
The strength of the produced Zn-based plated steel sheet and the like was evaluated by a tensile test in accordance with the regulation of JIS Z2241. As a result, the strength of the Zn-based plated steel sheet is 270MPa or more. Subsequently, an Al plate (a 6063) having a thickness similar to that of a Zn-based plated steel sheet or the like was prepared, and the strength of the Al plate was evaluated by the same method as described above, resulting in 200MPa or less. Therefore, it was confirmed that the Zn-based plated steel sheet and the like have high strength.
(1. Evaluation of Cooling liquid resistance)
The cooling liquid resistance of the manufactured Zn-based plated steel sheet or the like when used in a cooling structure (cooling device) of a battery device was examined. Specifically, a cup-shaped cylindrical processed product having a Φ50mm and a deep drawing height of 40mm was produced by performing ericsson's processing (Erichsen processing) on the Zn-based plated steel sheet or the like. After 30mL of the coolant was added to the inside of the cylindrical processed product, the product was covered with a lid and sealed. As the coolant, an aqueous solution in which a long-acting coolant of the japanese motor vehicle company is diluted with water to 30 mass% was used. These were left standing in a constant temperature bath at 90℃for 1000 hours, and the degradation of the steel sheet in the coolant-immersed portion was promoted. Further, assuming that degradation of the coolant occurs, the same test was performed using a degradation liquid obtained by adding 800ppm formic acid to a 30 mass% aqueous solution of the long-acting coolant. After the test, the cooling liquid impregnated in the cylindrical work was removed, and after the cylindrical work was dried, the corrosion state of the cooling liquid impregnated portion was observed, and the cooling liquid resistance was evaluated according to the following criteria. The results are shown in tables 5A to 5E.
5, the method comprises the following steps: no change in appearance
4, the following steps: the color change is black, or punctiform white rust is generated.
3, the method comprises the following steps: white rust is generated, but the white rust generation area of the coolant impregnation section is less than 20% relative to the total area of the coolant impregnation section.
2, the method comprises the following steps: the white rust generation rate is more than 20% and less than 80%.
1, the method comprises the following steps: white rust is produced at 80% or more, or red rust is produced.
(2. Corrosion resistance test)
As an evaluation of corrosion resistance at a portion of the battery device (including the cooling structure) that was exposed to the outside air, a corrosion resistance test was performed. Since electrodeposition coating is generally performed on a portion contacting the outside air, the corrosion resistance after electrodeposition coating is evaluated in the present invention.
Specifically, a steel slab obtained by cutting the produced steel sheet into dimensions of 70mm in width by 150mm in length is subjected to degreasing, surface conditioning, zinc phosphate treatment, and then to electrodeposition coating. Specifically, degreasing was performed by immersing a billet in a degreasing agent "FINE CLEANER E6408" manufactured by Nihon Parkerizing company at 60 ℃ for 5 minutes. The surface of the degreased billet was adjusted by immersing it in "PREPALENE X" manufactured by Nihon Parkerizing company at 40 ℃ for 5 minutes. Thereafter, the billet was immersed in a zinc phosphate chemical conversion agent "PALBOND L3065" manufactured by Nihon Parkerizing company at 35℃for 3 minutes to thereby carry out zinc phosphate treatment. The steel billet after the zinc phosphate treatment was washed with water and dried by passing through an oven in an atmosphere of 150 ℃. Thereafter, an electrodeposition coating material "Power coat 1200" manufactured by Nippon Paint Co., ltd was electrodeposition-coated on the steel billet at a thickness of 15 μm on each side, and baked in an oven at 170℃for 20 minutes. The steel billet for electrodeposition coating produced by the above steps was cut with a cutter to obtain a test piece.
The prepared test piece was used for a Cyclic Corrosion Test (CCT). The CCT model is performed in accordance with the automotive industry standard JASO-M609. The surface of the electrodeposition coating film on which cutting occurred was set as an evaluation surface, and the test machine was set with brine sprayed on the evaluation surface to conduct a cyclic corrosion test.
The test was conducted for 120 cycles (1 cycle for 8 hours), and the corrosion state from the cut portion was observed, and the corrosion resistance was evaluated according to the following criteria. The results are shown in tables 5A to 5E.
5, the method comprises the following steps: the swelling width of the coating film from the cutting part is less than 15mm, and no red rust is generated
4, the following steps: the swelling width of the coating film from the cutting part is more than 15mm and less than 20mm, and no red rust is generated
3, the method comprises the following steps: the swelling width of the coating film from the cutting part exceeds 20mm, and no red rust is generated
2, the method comprises the following steps: in the case where red rust is slightly generated from the cut portion
1, the method comprises the following steps: red rust is generated from the whole surface of the cutting part
< evaluation of Cooling Property in Battery device >
(1. Production of Battery device)
The battery device 1 shown in fig. 3 was produced using the produced Zn-based plated steel sheet or the like. Specifically, only a cut flat plate material is used as the case top cover (top surface portion 10 c) and the flow path top cover 26. The other portions (bottom surface portion 10a and side surface portion 10 b) of the battery pack 10 are manufactured by subjecting a Zn-based plated steel sheet or the like separately prepared thereto to square deep drawing by a press machine, and cutting the flange portion after the drawing. The bottom surface 10a of the battery pack 10 was processed so as to have a width of 315mm×a length of 2000 mm. During the working, rust preventive oil is applied to a Zn-based plated steel sheet or the like, and after the working, the oil is removed by alkali degreasing. The square punch shoulder R, die shoulder R, corner R were all set to 20mm. The cooling structure 20 is also manufactured by press working. Each R in the cooling structure 20 was set to 10mm, and was fabricated so that the number of channels, the width of channels, and the distance between channels became the values shown in table 4.
TABLE 4 Table 4
Distance between flow paths Flow channel width Number of flow paths Area ratio of cooling circuit to battery bottom surface
10mm 51mm 5 strips 0.81
15mm 45mm 5 strips 0.71
18mm 15mm 9 strips 0.43
30mm 41.25mm 4 strips 0.52
30mm 27mm 5 strips 0.43
30mm 17.5mm 6 strips 0.23
40mm 15mm 5 strips 0.23
45mm 9mm 5 strips 0.14
5mm 57mm 5 strips 0.9
50mm 3mm 5 strips 0.048
Next, a sealant 35 was applied to the joint 22 of the cooling structure 20 in the manner shown in fig. 3, and the cooling structure 20 and the flow path upper cover 26 were overlapped. Next, the joint 22 and the flow path upper cover 26 are joined by spot welding. Hereinafter, spot welding is also referred to as "SW". In several levels, instead of spot welding, use is made ofThe joint 22 is joined to the flow path cover 26 by a mechanical joining method "TOX" (registered trademark) manufactured by presotechnik corporation. In the case where the intervals between the water cooling medium passages 25 are as small as less than 10mm, and the welding nozzle for spot welding cannot be inserted, the two passages cannot be welded, and the passages are bonded only by the sealant. In addition, when the film thickness of the resin film covering the plated steel sheet exceeds 15 μm, the film is not conductive and welding is difficult, so that both the resin film and the sealant are bonded by the combination of TOX and the sealant. Next, the sealant was cured by leaving the cooling structure 20 at room temperature for 2 weeks. Note that, the secretAs the SEALANT, "SEALANT 45N" manufactured by Shin-Etsu Silicone company was used.
Next, "SDP-3540-a" manufactured by Shin-Etsu Silicone corporation was applied to the entire outer surface of the flow path upper cover 26, and the bottom surface 10a of the battery pack 10 was attached thereto in the manner shown in fig. 3, and left at room temperature for 1 week to cure the filler 40. Through the above steps, the battery device 1 shown in fig. 3 is manufactured. The battery device 1 shown in fig. 1 and 2 was also manufactured. Specifically, the battery pack 10 is directly joined to the flow path upper cover 26 in the manner shown in fig. 2. At this time, the flow path upper cover 26 is engaged with the battery pack 10 by a screw. Further, a sealant 35 is applied to the cooling structure 20 in the manner shown in fig. 1 so that the cooling structure 20 overlaps the battery pack 10. Next, the joining portion 22 and the battery pack 10 are joined by spot welding. In the case where the interval between the water cooling medium passages 25 is as small as less than 10mm, the welding nozzle for spot welding cannot be inserted, and the two cannot be welded, the two cannot be adhered to each other only by the sealant.
Next, a rubber heater is laid on the bottom surface of the inside of the battery pack 10, and a cover is put on the cover with a case instead of the battery device that generates heat. When the lid is closed, the sealant 10d is applied to the flange of the case, and the case is set in a closed state. As the SEALANT, SEALANT 45N manufactured by Shin-Etsu Silicone company was used. The metal materials constituting the battery pack 10 and the cooling structure 20 are set to be the same metal material. That is, the battery pack 10, the flow path upper cover 26, and the cooling structure 20 constituting 1 battery device 1 are manufactured from the same metal material.
(2. Test for evaluating Cooling Properties of Battery device)
A current is passed through the rubber heater of the fabricated battery device 1 to heat the battery device 1. Here, a current value at which the surface temperature of the rubber heater becomes 50 ℃ was previously searched for, and the current value was set to a fixed value and was circulated through the rubber heater. Next, the coolant flows through the water-cooling medium flow path 25. As the coolant, a long-acting coolant of pitfork corporation was diluted with water to a 30 mass% aqueous solution. Further, hoses, pumps, and coolers are attached to the flow path ends on both sides of the cooling structure 20 to form a circulation path, and the coolant is circulated in the circulation path. Here, the cooler is controlled so that the temperature of the cooling water becomes 25 to 30 ℃. Then, the temperature of the surface of the rubber heater in the housing immediately above the intermediate portion between the cooling channels after 1 hour from the start of the cooling water circulation was measured, and the temperature was evaluated as excellent when the temperature was lower by 8 ℃ or more than that in the case where the cooling water was not circulated, as excellent when the temperature was lower by less than 8 ℃ and 5 ℃ or more, as delta when the temperature was lower than 5 ℃ and 2 ℃ or more, and as×whenthe temperature was lower than 2 ℃. The cooling characteristic evaluation test of the battery device 1 was performed in a room kept at 25 ℃ by an air conditioner. The results are shown in tables 5A to 5E.
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As shown in tables 5A to 5E, in the present application examples satisfying the requirements of the present embodiment, excellent results were obtained not only with respect to the corrosion resistance of the coolant (coolant corrosion resistance) but also with respect to the corrosion resistance of the external environment (external corrosion resistance). In addition, in most of the examples of the present application, the cooling efficiency was also high as a result of evaluation. In the case where the plating layer is Zn-Al-Mg, the distance between the water-cooling medium passages is 40mm or lessIn the case where the rust preventive component is contained in the inorganic film, the thickness of the resin film is 1.0 to 15 μm, the conductive pigment is contained in the resin film, and the powder resistivity of the conductive pigment is 185×10 -6 Particularly excellent results are obtained in the case of Ω cm or less, for example. Therefore, it is known that the battery device 1 of the present embodiment is excellent not only in corrosion resistance against a coolant (coolant corrosion resistance), but also in corrosion resistance against the external environment (external corrosion resistance).
In contrast, in the comparative example, i.e., in the case where the chemical conversion coating film is not applied or in the case where plating is not performed, which does not satisfy the requirements of the present embodiment, either (or both) of the coolant corrosion resistance and the external corrosion resistance are poor results.
The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious that various modifications and modifications are conceivable within the scope of the technical idea described in the claims, and it is needless to say that these modifications and modifications fall within the technical scope of the present invention, as long as they have a common knowledge in the technical field to which the present invention pertains.
Symbol description
1 Battery apparatus
10. Battery pack
10a bottom surface portion
10b side face portion
10c upper surface portion
20. Cooling structure
21. Flow channel forming part
22. Joint part
25. Flow path for water-cooling medium
30. Spot welding part

Claims (17)

1. A battery device is characterized by comprising a battery pack for accommodating battery cells and a flow path for a water cooling medium formed on the outer side of the bottom surface of the battery pack,
the water cooling medium flow path is composed of a Zn-based plated steel sheet,
an inorganic film or a resin film is formed as a chemical conversion treatment film on the surface of the Zn-coated steel sheet,
the inorganic film contains a Si-based component or a Zr-based component as a main component.
2. The battery device according to claim 1, wherein the water-cooling medium flow paths are spaced apart from each other by 40mm or less.
3. The battery device according to claim 1 or 2, wherein the bottom surface of the battery pack is formed of a member obtained by processing the Zn-based plated steel sheet, and the water cooling medium flow path is in direct contact with the bottom surface of the battery pack.
4. The battery device according to claim 1 or 2, wherein the water-cooling medium flow path is joined to a flow path upper cover made of the Zn-based plated steel sheet, and the water-cooling medium flow path is joined to the bottom surface of the battery pack via the flow path upper cover.
5. The battery device according to any one of claims 1 to 4, wherein the water-cooling medium flow paths are spaced apart from each other by 10mm to 40 mm.
6. The battery device according to any one of claims 1 to 5, wherein the water-cooling medium flow paths are spaced apart from each other by 10mm or more and 40mm or less,
the joint between the bottom surface of the battery pack and the water-cooling medium flow path is a composite joint structure of sealant and spot welding or sealant and mechanical joint.
7. The battery device according to any one of claims 1 to 6, wherein the inorganic coating film contains at least 1 or more of a V component, a P component, and a Co component as a rust preventive component.
8. The battery device according to claim 7, wherein the rust preventive component is one or more of vanadium oxide, phosphoric acid, and cobalt nitrate.
9. The battery device according to any one of claims 1 to 8, wherein the inorganic film or the resin film has conductivity.
10. The battery device according to any one of claims 1 to 9, wherein the inorganic coating film is composed of a compound phase containing 1 or more of si—o bonds, si—c bonds, and si—oh bonds.
11. The battery device according to any one of claims 1 to 10, wherein the inorganic coating film has a thickness of more than 0 μm and 1.5 μm or less.
12. The battery device according to any one of claims 1 to 6, wherein the resin film contains a resin, an anti-rust pigment, and a conductive pigment.
13. The battery device according to claim 12, wherein the resin film contains any one or more of metal particles, intermetallic compound particles, conductive oxide particles, and conductive non-oxide ceramic particles as the conductive pigment,
the powder resistivity of the conductive pigment at 25 ℃ is 185 multiplied by 10 -6 Ω cm or less, and contains any one or more selected from the group consisting of Zn, si, zr, V, cr, mo, mn, fe and W as constituent elements.
14. The battery device according to claim 12 or 13, wherein the resin film contains the conductive pigment in a proportion of 1.0 mass% or more and 30 mass% or less.
15. The battery device according to any one of claims 12 to 14, wherein the resin film has an average thickness of 1.0 μm or more and 15 μm or less.
16. The battery device according to any one of claims 1 to 11, wherein the Zn-based plated steel sheet is a Zn-Al-Mg plated steel sheet,
an inorganic coating film containing a Si-based component as a main component is formed on the surface of the Zn-Al-Mg-plated steel sheet.
17. The battery device according to any one of claims 1 to 6 and 12 to 15, wherein the Zn-based plated steel sheet is a Zn-Al plated steel sheet,
a resin film is formed on the surface of the Zn-Al plated steel sheet.
CN202280017442.XA 2021-03-01 2022-02-07 battery device Pending CN116918142A (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2021-031920 2021-03-01
JP2021-087651 2021-05-25
JP2021087651 2021-05-25
PCT/JP2022/004683 WO2022185849A1 (en) 2021-03-01 2022-02-07 Battery unit

Publications (1)

Publication Number Publication Date
CN116918142A true CN116918142A (en) 2023-10-20

Family

ID=88355167

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202280017442.XA Pending CN116918142A (en) 2021-03-01 2022-02-07 battery device

Country Status (1)

Country Link
CN (1) CN116918142A (en)

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