JP2019188743A - Restorable plating substrate - Google Patents

Abstract

To provide a restorable plating substrate showing more sufficient corrosion resistance.SOLUTION: A restorable plating substrate having, on a surface of a metal substrate, a plating layer containing a metal A having a higher ionization tendency than a metal constituting the metal substrate, and two or more layers of polymer layers formed on the plating layer, in which the polymer layers of two or more layers contain a compound containing a metal B having the ionization tendency higher than a metal constituting a phosphate compound, a phosphonate compound and a metal constituting the metal substrate, the compound containing the metal B having higher ionization tendency is contained in a polymer layer different from the polymer layer in which at least one of the phosphate compound or the phosphonic acid compound is included.SELECTED DRAWING: None

Description

  The present invention relates to a repairable plating base material.

  As an automobile part, a galvanized steel sheet in which a galvanized layer is formed on the surface of the steel sheet is generally used. Zinc contained in the galvanized layer shows a higher ionization tendency than iron contained in the steel plate. For this reason, when a scratch is formed in the galvanized layer and the steel sheet is exposed, the galvanized layer has a sacrificial anticorrosive performance in which zinc elutes and a protective film in which the eluted zinc forms a film on the surface of the exposed steel sheet Has the ability to form, self-repairs, and exhibits corrosion resistance. However, the conventional galvanized steel sheet cannot exhibit sufficient corrosion resistance.

  Therefore, Patent Document 1 reports an anticorrosion coating provided on the surface of a metal substrate, which has a base portion made of conductive fine particles and a surface portion made of a conductive polymer. However, even in such a technique, it cannot be said that sufficient corrosion resistance is exhibited.

  Patent Document 2 discloses a restoration agent containing zinc sulfate, sodium dihydrogen phosphate and aminotris (methylene phosphonic acid).

JP 2010-174273 A JP-A-2018-28115

  The inventors of the present invention have found a new problem that sufficient corrosion resistance cannot be obtained even if one polymer layer is formed on the surface of the plating layer and the restoration agent of Patent Document 2 is contained in the polymer layer. .

  An object of this invention is to provide the repairable plating base material which shows more sufficient corrosion resistance.

The present invention
The surface of the metal substrate has a plating layer containing metal A having a higher ionization tendency than the metal constituting the metal substrate, and two or more polymer layers formed on the plating layer, A repairable plating base material comprising a compound containing two or more polymer layers containing a phosphoric acid compound, a phosphonic acid compound and a metal B having a higher ionization tendency than the metal constituting the metal base material,
The compound containing metal B having a high ionization tendency is contained in a polymer layer different from the polymer layer containing at least one of the phosphoric acid compound and the phosphonic acid compound among the two or more polymer layers. , Restorative plating substrate,
About.

The restorable plating base material of the present invention exhibits further sufficient corrosion resistance. Specifically, the restorative plating base material of the present invention is more excellent in sacrificial anticorrosion performance and protective film forming ability even if scratches (scratches) reaching the metal base material are formed under the actual use environment. Furthermore, it has good self-repairing properties and exhibits more sufficient corrosion resistance.
The repairable plating substrate of the present invention is particularly useful when a high-tensile material (high-tensile steel plate) is used as the metal substrate.

The schematic sectional drawing of an example of the plating base material which can be used for the repairable plating base material of this invention is shown. The schematic sectional drawing of the repairable plating base material which concerns on 1st embodiment of this invention is shown. The schematic sectional drawing of the repairable plating base material for demonstrating an example in which a defect (scratch) is formed in the repairable plating base material which concerns on 1st embodiment of this invention, and a protective film is formed is shown. The schematic sectional drawing of the repairable plating base material which concerns on the 2nd embodiment of this invention is shown. The schematic sectional drawing of the repairable plating base material for demonstrating an example of the aspect in which a defect (scratch) is formed in the repairable plating base material which concerns on 2nd embodiment of this invention, and a protective film is formed is shown. The schematic sectional drawing of the test piece produced in Example 1 is shown. The schematic sectional drawing of the test piece produced in Example 2 is shown. The schematic sectional drawing of the test piece produced in the comparative example 1 is shown. The schematic sectional drawing of the test piece produced in the comparative example 2 is shown. The schematic sectional drawing of the test piece produced by the reference example 1 is shown. The schematic sectional drawing of the test piece produced in Example 3 is shown. The schematic block diagram of the apparatus for evaluating the restoration | repair agent of this invention is shown. The graph showing the relationship of the immersion time-polarization resistance of the test piece produced in the Example is shown. The graph showing the relationship of the immersion time-polarization resistance of the test piece produced in the Example is shown. The schematic sectional drawing for demonstrating the difference in the formation mechanism of a protective film when using the test piece produced in Example 1 and Example 3 is shown. The scanning electron microscope (SEM) photograph of the steel plate exposure surface in the wound part at the time of 48-hour immersion time in the test piece of Example 1 is shown. It is the mapping image of Fe element in FIG. 11A. It is a mapping image of Zn element in FIG. 11A. It is a mapping image of the P element in FIG. 11A. It is a mapping image of the O element in FIG. 11A. It is a mapping image of N element in FIG. 11A. It is an enlarged photograph of the enclosure part by the white line in FIG. 11A. It is an enlarged photograph of the enclosure part by the white line in FIG. 11B. It is an enlarged photograph of the enclosure part by the white line in FIG. 11E. It is an enlarged photograph of the enclosure part by the white line in FIG. 11C. It is an enlarged photograph of the enclosure part by the white line in FIG. 11D. The scanning electron microscope (SEM) photograph of the steel plate exposure surface in the wound part at the time of immersion time 3 hour passage in the test piece of Example 1 is shown. It is the mapping image of Fe element in FIG. 12A. It is a mapping image of Zn element in FIG. 12A. It is a mapping image of O element in FIG. 12A. It is a mapping image of P element in FIG. 12A. It is a mapping image of N element in FIG. 12A. The scanning electron microscope (SEM) photograph of the steel plate exposure surface in the wound part at the time of 48-hour immersion time in the test piece of the reference example 1 is shown. It is the mapping image of Fe element in FIG. 13A. It is a mapping image of Zn element in FIG. 13A. It is the mapping image of O element in FIG. 13A. It is a mapping image of P element in FIG. 13A. It is a mapping image of N element in FIG. 13A. The scanning electron microscope (SEM) photograph of the steel plate exposure surface in the wound part at the time of 48-hour immersion time in the test piece of Example 3 is shown. It is the mapping image of Fe element in FIG. 14A. It is the mapping image of Zn element in FIG. 14A. It is a mapping image of O element in FIG. 14A. It is the mapping image of P element in FIG. 14A. The graph showing the error range (error bar) of the polarization resistance 48 hours after in the test piece produced in Example 1 etc. is shown.

[Repairable plating substrate]
The repairable plating substrate of the present invention has a polymer layer formed on the plating layer of the plating substrate. Since the repairable plating substrate of the present invention contains a repairing agent in the polymer layer, when a defect reaching the metal substrate from the surface of the polymer layer is formed, the inner surface of the defect, particularly the surface of the exposed metal substrate is protected. A film is formed and has a restorability (particularly self-healing). Hereinafter, the present invention will be described in detail with reference to the drawings, but various elements in the drawings are merely schematically and exemplarily for understanding the present invention, and the appearance and dimensional ratio are different from the actual ones. obtain. The “vertical direction”, “left / right direction”, and “front / back direction” used directly or indirectly in this specification correspond to directions corresponding to the vertical direction, left / right direction, and front / back direction in the drawing, respectively. Unless otherwise specified, the same symbols or symbols indicate the same members or the same meaning.

(Plating substrate)
As shown in FIG. 1A, the plating substrate 10 includes a metal substrate 1 and a plating layer 2 formed on the surface of the metal substrate. The metal substrate 1 may be any substrate containing a metal, and usually contains iron, and may contain carbon, silicon, manganese, phosphorus, sulfur and the like as desired. In the metal substrate, the carbon content is 1% by weight or less, particularly 0.8% by weight or less, and the content of silicon, manganese, phosphorus, sulfur, etc. is 0.5% by weight or less, particularly 0.3% by weight, respectively. %, And the balance is iron.

  The metal substrate 1 is preferably a steel plate in the field of automobile parts, more preferably a so-called carbon steel plate, particularly a high-tensile steel plate (high-tensile material).

  The plating layer 2 contains a metal whose ionization tendency is higher than that of the metal constituting the metal substrate 1 as a main component. The metal having a high ionization tendency that is contained as the main component of the plating layer may be hereinafter referred to as “metal A having a high ionization tendency”. When the metal substrate 1 is a steel plate, the metal constituting the metal substrate 1 is iron. Examples of the metal having a higher ionization tendency than iron include one or more metals selected from the group consisting of zinc, aluminum, magnesium, and zirconium. Zinc is preferable. The metal A having a high ionization tendency contained in the plating layer 2 is usually in the form of ions and contributes to the formation of a protective film described in detail later.

  The plating layer 2 is preferably a galvanized layer from the viewpoint of forming a protective film on the exposed surface of the metal substrate 1. The zinc plating layer is a plating layer containing zinc, and preferably a zinc alloy layer.

  As a method for forming the plating layer 2, any plating method may be employed. For example, a so-called electroplating method, electroless plating method, hot plating method such as a hot dipping method, and so-called vacuum plating method (physical vapor deposition). Method (PVD method)), chemical vapor deposition (CVD), and impact plating. A dry plating method, particularly an impact plating method is preferred. In the impact plating method, a plating layer (film) is formed by projecting composite particles having metal particles constituting the plating layer on the outer shell of the central portion (for example, iron core) onto the object to be processed (metal substrate 1). It is a method to do. In FIG. 1A, a schematic cross-sectional view of a plating substrate in which the plating layer 2 is formed by impact plating and the interfaces and gaps of the constituent metal particles exist inside the plating layer 2 is shown. It may be formed by a method and have a form in which there are no interfaces and gaps between the constituent metal particles.

  The thickness of the plating layer 2 is not particularly limited, and may be, for example, 1 μm or more, and is usually 1 to 50 μm, particularly 1 to 10 μm.

(Restoration agent)
The restoration agent includes a phosphoric acid compound, a phosphonic acid compound, and a compound containing a metal having a higher ionization tendency than the metal constituting the metal substrate 1 (hereinafter sometimes referred to as compound B). The restoration agent is an agent that forms a protective film on the exposed surface of the metal substrate.

The phosphate compound is one or more inorganic phosphate compounds selected from the group consisting of phosphoric acid (H ₃ PO ₄ ) and phosphate. From the viewpoint of forming a protective film, a phosphate is preferable. The phosphate is a phosphate ion such as a first phosphate ion (H ₂ PO ₄ ⁻ ), a second phosphate ion (HPO ₄ ²⁻ ), or a third phosphate ion (PO ₄ ³⁻ ), and a positive ion. It is a salt with ions. From the viewpoint of forming the protective film, preferred phosphate ions are a first phosphate ion and a second phosphate ion, and more preferably a first phosphate ion. The cation is one or more ions selected from the group consisting of monovalent metal ions, divalent metal ions, trivalent metal ions and ammonium ions. Preferred are monovalent metal ions and ammonium ions. Examples of the metal constituting the monovalent metal ion include alkali metals (for example, sodium, potassium and lithium), preferably sodium and potassium. Examples of the metal constituting the divalent metal ion include alkaline earth metals (eg, magnesium, calcium, strontium, barium) and manganese, preferably calcium, barium and manganese. As a metal which comprises a trivalent metal ion, chromium and aluminum are mentioned, for example, Preferably it is chromium.

Specific examples of preferred phosphoric acid compounds from the viewpoint of forming a protective film include, for example, phosphoric acid (H ₃ PO ₄ ), sodium dihydrogen phosphate, potassium dihydrogen phosphate, ammonium dihydrogen phosphate, calcium dihydrogen phosphate. , Barium dihydrogen phosphate, manganese dihydrogen phosphate, lithium dihydrogen phosphate, sodium ammonium hydrogen phosphate, diammonium hydrogen phosphate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, barium hydrogen phosphate, phosphoric acid Mention may be made of manganese hydrogen (II), chromium (III) phosphate, tripotassium phosphate, trisodium phosphate, and condensed phosphate compounds. The condensed phosphoric acid compound is, for example, a compound composed of an anion and a cation such as tripolyphosphoric acid, pyrophosphoric acid, metaphosphoric acid, phosphorous acid, etc., and the cation includes, for example, an alkali metal ion, an alkaline earth metal ion, and It is selected from amphoteric metal ions (zinc ions, aluminum ions).

  More preferable phosphoric acid compounds from the viewpoint of forming a protective film include sodium dihydrogen phosphate, potassium dihydrogen phosphate, ammonium dihydrogen phosphate, sodium ammonium hydrogen phosphate, diammonium hydrogen phosphate, and dipotassium hydrogen phosphate. , Disodium hydrogen phosphate, trisodium phosphate, and condensed phosphate compounds. Specific examples of preferable condensed phosphate compounds include, for example, aluminum trihydrogenphosphate, calcium tripolyphosphate, zinc tripolyphosphate, sodium tripolyphosphate, calcium metaphosphate, calcium metaphosphate, calcium pyrophosphate, calcium pyrophosphate, aluminum phosphite, zinc phosphite Etc.

  Phosphoric acid compounds are readily available as commercial products. Two or more compounds may be used as the phosphoric acid compound.

The phosphonic acid compound is not particularly limited as long as it contains an atom having an unshared electron pair that contributes to the adsorption of the protective film to the metal substrate 1, and for example, a group consisting of a nitrogen-containing phosphonic acid compound and a salt thereof One or more organic phosphonic acid compounds selected from: The organic phosphonic acid compound means a compound having an organic group and a phosphono group. Examples of the organic group include an alkylene group, and an alkylene group having 1 to 3 carbon atoms is particularly preferable. The phosphono group is represented by —P (═O) (OH) ₂ and may have a salt form. The phosphono group having a salt form means that a hydrogen ion at the hydroxyl group of the phosphono group may be released and substituted with a metal ion or the like. Examples of the metal ion include sodium ion, potassium ion, and calcium ion.

The nitrogen-containing phosphonic acid compound is not particularly limited as long as it is an organic compound containing a nitrogen atom and a phosphono group. For example, aminotris (methylenephosphonic acid) (ATMP) (structural formula: N [CH ₂ PO (OH)) ₂ ] ₃ ), aminotris (ethylene phosphonic acid) (structural formula: N [CH ₂ CH ₂ PO (OH) ₂ ] ₃ ), and phosphono group-containing amines such as metal salts thereof. In the case where the compound has two or more hydroxyl groups in one molecule, the metal salt may be one in which hydrogen ions at some hydroxyl groups are replaced with metal ions, or hydrogen ions at all hydroxyl groups are present. It may be substituted with a metal ion.

  The phosphonic acid compound is easily available as a commercial product. Two or more compounds may be used as the phosphonic acid compound.

  The phosphoric acid compound and the phosphonic acid compound are usually contained in a weight ratio of 10/90 to 90/10 (phosphoric acid compound / phosphonic acid compound), and preferably 20/80 to 80/20 from the viewpoint of forming a protective film. More preferably, it is contained in a weight ratio of 40/60 to 80/20, more preferably 45/55 to 65/35. When using 2 or more types of compounds as a phosphoric acid compound, those total amounts should just be in the said range. When using 2 or more types of compounds as a phosphonic acid compound, those total amounts should just be in the said range.

  The compound B is a compound containing a metal having a higher ionization tendency than the metal constituting the metal substrate 1. In the present specification, a metal having a high ionization tendency contained in such a compound B contained in the restorative agent is distinguished from a metal A having a high ionization tendency contained in the plating layer. There is. Such a metal B having a high ionization tendency also contributes to the formation of a protective film in the form of ions. The metal B having a high ionization tendency may be selected from metals in the same range as the metal A having a high ionization tendency, and is preferably the same type of metal as the metal A having a high ionization tendency.

  The metal B having a high ionization tendency is not particularly limited as long as the metal can exist in the form of ions in water, and examples thereof include zinc, iron, magnesium, cobalt, nickel, chromium, silver, zirconium, and aluminum. From the viewpoint of forming a complex in water, particularly from the viewpoint of forming a complex with ATMP, among these metals, divalent to tetravalent (preferably divalent and tetravalent) metals, particularly zinc, iron, nickel, Zirconium is preferred and zinc is more preferred. The compound containing metal B having a high ionization tendency is not particularly limited as long as the metal can exist in the form of ions in water. Preferable specific examples of the compound containing metal B having a high ionization tendency include, for example, zinc sulfate, iron sulfate, nickel sulfate, zirconium sulfate, zinc nitrate, aluminum sulfate, aluminum nitrate, magnesium sulfate, magnesium nitrate and the like.

  The compound B containing the metal B having a high ionization tendency is preferably contained in an amount of 10 to 400 parts by weight with respect to 100 parts by weight of the total amount of the phosphoric acid compound and the phosphonic acid compound. From 30 to 300 parts by weight, more preferably from 80 to 300 parts by weight, still more preferably from 80 to 200 parts by weight, and most preferably from 110 to 150 parts by weight. Two or more kinds of compounds may be used as the compound B containing the metal B having a high ionization tendency, and in this case, the total amount thereof may be within the above range.

By containing a combination of a phosphoric acid compound, a phosphonic acid compound and compound B, the restorative agent can form a protective film excellent in non-conductivity and adhesion on the surface of the metal substrate exposed by the formation of defects. Corrosion resistance is more fully improved. Instead of phosphoric acid compounds, compounds such as nitric acid compounds, carbonic acid compounds, hydrogen carbonate compounds, chromic acid compounds, silicic acid compounds, metal fluorides, metal oxides, or aromatic compounds can be used instead of phosphonic acid compounds. Even when an aliphatic carboxylic acid or an organic amine is used, a protective film is not formed, or even if it is formed, at least one of the non-conductive property or the adhesive property of the protective film is lowered, so that sufficient corrosion resistance is obtained. Absent. If the restoration agent does not contain compound B, the protective film is not sufficiently formed, so that sufficient corrosion resistance cannot be obtained. In the present specification, the term “nonconductive” refers to an insulating property having a volume resistivity of 10 ¹² Ω · cm or more.

  In the present invention, a protective film is formed on the surface of the metal substrate on which the metals A and B, the phosphoric acid compound and the phosphonic acid compound having a high ionization tendency are exposed. That is, during the formation of the protective film, the phosphate ion of the phosphate compound reacts with the ion of metal A contained in the plating layer having a high ionization tendency and the ion of metal B contained in compound B having a high ionization tendency ( For example, according to the following general reaction formula (I)), a non-conductive compound is produced as the main skeleton component of the film. On the other hand, the phosphonic acid compound forms a complex with the ions of metals A and B, which have a high ionization tendency (for example, the following general reaction formula (II)), and the nitrogen atom contained in the phosphonic acid compound portion is an unshared electron. The pair exerts an adsorption action with the surface of the metal substrate. Moreover, the presence of the phosphonic acid compound complex promotes the amorphization of the film, and improves the flexibility and adhesion of the film to the surface of the metal substrate. As a result, it is considered that a protective film excellent in non-conductivity and adhesion is formed, and the corrosion resistance is more sufficiently improved. In addition, the following general reaction formula is an example which shows roughly formation of the product derived from the main substance concerning formation of a protective film.

  In this specification, the corrosion resistance is a characteristic that resists corrosion, and is a characteristic that can sufficiently resist corrosion even when a defect is formed and a metal substrate is exposed. Corrosion resistance shall be used in a concept that includes self-healing properties. Self-healing is a characteristic that even if a metal substrate is exposed due to the formation of a defect, a protective film is formed on the surface of the exposed metal substrate, thereby exhibiting a behavior that repairs the defect. is there.

  The repair agent does not necessarily contain nanofibers, but preferably contains nanofibers. A nanofiber is a fiber having a nano-order diameter. By including such nanofibers in the restorative agent, the restorative plating base material further exhibits sufficient corrosion resistance. Although the details of the mechanism by which the restorative plating base material further exhibits sufficient corrosion resistance when the restorative agent contains nanofibers are not clear, it is thought to be based on the following principles and principles. When the nanofiber is contained, components such as a phosphoric acid compound, a phosphonic acid compound, and a compound B (hereinafter sometimes referred to as a phosphoric acid compound) move along the surface of the nanofiber. For this reason, when a defect (scratch) is formed, the movement of these components in the polymer layer described later is promoted, and the exudation from the layer is promoted. As a result, it is considered that a protective film (restoration film) is more effectively formed on the exposed surface of the metal substrate in the scratched part and exhibits sufficient corrosion resistance.

  As long as the diameter of the nanofiber has a nano-order, the constituent material is not particularly limited. Specific examples of nanofibers include, for example, natural polymer nanofibers such as cellulose nanofiber, chitosan nanofiber, and gelatin nanofiber; polyolefin nanofiber, polyamide nanofiber, polyvinylidene fluoride nanofiber, acrylic nanofiber, and epoxy nano Examples thereof include synthetic polymer nanofibers such as fibers, polyurethane nanofibers, and polyimide nanofibers; and carbon nanofibers and carbon nanotubes. From the viewpoint of further promoting the exudation of phosphate compounds and the like, preferred nanofibers are natural polymer nanofibers, particularly cellulose nanofibers. Cellulose nanofibers are fibers obtained by finely loosening plant fibers obtained from plants to nanosize, and those known as so-called reinforcing fibers in the field of plastics can be used.

  The average fiber diameter of the nanofiber is usually 1 nm or more and 1000 nm or less, and preferably 1 to 500 nm, more preferably 10 to 400 nm, and still more preferably 100 to 300 nm, from the viewpoint of promoting exudation of a phosphate compound or the like.

  The average fiber length of the nanofiber is usually 10 to 1000 μm, and preferably 50 to 800 μm, more preferably 100 to 500 μm, and still more preferably 200 to 400 μm from the viewpoint of promoting exudation of a phosphate compound or the like.

  As the average fiber diameter and average fiber length of the nanofiber, an average value of arbitrary 200 values measured from a micrograph (SEM) is used.

  When the restorative agent includes nanofibers, the nanofibers are preferably contained in an amount of 1 to 200 parts by weight with respect to 100 parts by weight of the total amount of the phosphoric acid compound and the phosphonic acid compound. From this point of view, the content is particularly preferably 5 to 100 parts by weight, more preferably 10 to 80 parts by weight, still more preferably 10 to 60 parts by weight, and most preferably 20 to 40 parts by weight. Two or more kinds of compounds may be used for the nanofiber, and in that case, the total amount thereof may be within the above range.

(Polymer layer)
The polymer layer has a multilayer structure of two or more layers and contains a restorative agent. For example, when the polymer layer has a two-layer structure, as shown in FIG. 1B, the first polymer layer 41 and the second polymer layer 42 are sequentially formed (or laminated) on the plating layer 2, and as a result, the 2 The polymer layer having a layer structure includes a first polymer layer 41 laminated on the plating layer 2 and a second polymer layer 42 laminated on the first polymer layer 41. Further, for example, when the polymer layer has a three-layer structure, as shown in FIG. 1D, the first polymer layer 41, the second polymer layer 42, and the third polymer layer 43 are sequentially (or laminated) on the plating layer 2. As a result, the polymer layer having the three-layer structure includes a first polymer layer 41 laminated on the plating layer 2, a second polymer layer 42 laminated on the first polymer layer 41, and the second polymer. A third polymer layer 43 laminated to the layer 42 is included. In the present specification, each polymer layer includes at least one component among the components of a phosphate compound, a phosphonate compound, a nanofiber, and a compound B constituting the restoration agent. Accordingly, each polymer layer can also be referred to as a restorative polymer layer from the viewpoint of contributing to the formation of a protective film.

  Two or more polymer layers constituting the polymer layer have different compositions. The difference in composition means that at least one selected from the group consisting of the type and amount of the component of the restoration agent contained in the polymer layer and the type of polymer constituting the polymer layer is different. The two or more polymer layers are usually different from each other in the types of components of the restoration agent contained therein.

  In the present invention, compound B is contained in a polymer layer different from a polymer layer containing at least one of a phosphoric acid compound or a phosphonic acid compound among two or more polymer layers. Specifically, Compound B is contained in a polymer layer that does not contain a phosphoric acid compound or a phosphonic acid compound. More specifically, the compound B is contained in another polymer layer adjacent to and separated from the polymer layer containing at least one of the phosphoric acid compound and the phosphonic acid compound. Separation is the presence of a polymer layer that separates the interface between two polymer layers. In the present invention, by including compound B in a polymer layer that does not contain a phosphoric acid compound or a phosphonic acid compound, the restorable plating base material exhibits further sufficient corrosion resistance. The details of the mechanism are not clear, but are thought to be based on the following principles. When compound B is contained together with a phosphoric acid compound and / or a phosphonic acid compound in one polymer layer, the reactions (I) and / or (II) occur in the polymer layer, and products are formed. Exudation and release of components out of the layer is prevented. Therefore, when compound B is contained in a polymer layer different from the polymer layer containing at least one of the phosphoric acid compound and / or the phosphonic acid compound, the reaction (I) and / or (II) in the layer is performed. Therefore, when the defect 13 reaching the metal substrate 1 as shown in FIGS. 1C and 1E is formed, each component is smoothly exuded and released out of the layer. As a result, it is considered that the protective film (restoration film) 14 is more effectively formed on the exposed surface of the metal base material in the scratched part, and exhibits further sufficient corrosion resistance. The movement of each component exuded from each polymer layer to the exposed surface of the metal substrate 1 may be achieved by moisture (for example, rainwater) adhering to the defect 13 or may be achieved by moisture in the air. Alternatively, it may be achieved by immersing the repairable plating substrate in which the defect 13 is formed in water. When compound B is contained in a polymer layer containing at least one of a phosphoric acid compound and / or a phosphonic acid compound, reaction (I) and / or (II) occurs in the polymer layer, resulting in a product. The exudation and release of each component out of the layer are hindered, and the restorable plating substrate does not exhibit sufficient corrosion resistance.

In the repairable plating substrate of the present invention, the protective film 14 is selectively formed on the exposed surface of the metal substrate 1. This is not intended to be bound by any particular theory, but may be due to the following reasons.
(1) Since the metal substrate 1 initially has a corrosion potential (negative), when the metals A and B having a high ionization tendency are electrostatically attracted to the exposed surface of the metal substrate 1 as positive ions, These constituent materials are also electrostatically attracted to the positive ions.
(2) The attracted ions are adsorbed on the surface of the metal substrate 1 and then bonded to each other to form a film. These form a two-dimensional or three-dimensional film, and at the same time, strongly adsorb or bond to the surface of the metal substrate 1 to form a highly adhesive film.

  The formation of the protective film 14 on the exposed surface of the metal substrate 1 can be easily confirmed by an SEM photograph of the surface or by analysis of the film on the surface by XRD (X-ray diffraction method). be able to.

  In the present specification, the defect 13 has a depth reaching the metal substrate 1 from the surface of the polymer layer, and is also referred to as a scratch.

  Specific examples of the polymer layer configuration in the present invention include the following configuration examples. In the following notation, when the polymer layer is a two-layer type, the component described on the left side is a component included in the first embodiment 41, and the component described on the right side is a component included in the second polymer layer 42. is there. When the polymer layer is a three-layer type, the component described on the left side is a component included in the first embodiment 41, the component described in the center is a component included in the second polymer layer 42, and the component described on the right side Is a component contained in the third polymer layer 43.

Two-layer type: first polymer layer 41 / second polymer layer 42
Configuration Example A1 = Compound B / Phosphate Compound + Phosphonate Compound Configuration Example A2 = Phosphate Compound + Phosphonate Compound / Compound B

Three-layer type: first polymer layer 41 / second polymer layer 42 / third polymer layer 43
Configuration Example B1 = Compound B / Phosphonic acid compound / Phosphate Compound Configuration Example B2 = Compound B / Phosphate Compound / Phosphonate Compound Configuration Example B3 = Phosphonate Compound / Compound B / Phosphate Compound Configuration Example B4 = Phosphonate Compound / Phosphoric acid compound / Compound B
Configuration Example B5 = Phosphate Compound / Compound B / Phosphonate Compound Configuration Example B6 = Phosphate Compound / Phosphonate Compound / Compound B

  In the present invention, for example, when the first polymer layer 41 and the second polymer layer 42 are sequentially formed on the plating layer 2, as in the structural examples A1 and A2, the compound B contains the first polymer layer 41 and The second polymer layer 42 is included in one polymer layer, and the phosphoric acid compound and the phosphonic acid compound are included in the other polymer layer. At this time, from the viewpoint of further improving the corrosion resistance of the restorable plating base material, the compound B is included in the first polymer layer 41 as in the configuration example A1, and the phosphate compound and the phosphonic acid compound are the second polymer. It is preferable that it is contained in the layer.

  Further, for example, when three polymer layers (reference numerals 41 to 43) are formed on the plating layer 2, the compound B is one of the three polymer layers as in the structural examples B1 to B6. The phosphoric acid compound and the phosphonic acid compound are contained in different polymer layers among the two polymer layers other than the polymer layer containing the compound B, respectively. When the 1st polymer layer 41, the 2nd polymer layer 42, and the 3rd polymer layer 43 are formed in order on the plating layer 2, from a viewpoint of the further improvement of the corrosion resistance of a repairable plating base material, structural example B1 and B2 As described above, the compound B is contained in the first polymer layer 41, the phosphoric acid compound is contained in one of the second polymer layer 42 or the third polymer layer 43, and the phosphonic acid compound. Is preferably contained in the other polymer layer. From the viewpoint of further improving the corrosion resistance of the repairable plating base material, more preferably, as in the structural example B1, the compound B is contained in the first polymer layer 41, and the phosphoric acid compound is contained in the third polymer layer 43. The phosphonic acid compound is contained in the second polymer layer 42.

  In each of the above configuration examples, all the polymer layers do not contain nanofibers. However, from the viewpoint of smoother exudation of each component, the nanofibers are formed into polymer layers containing other components of the repair agent. It is preferably included. The other component is at least one component selected from the phosphoric acid compound, the phosphonic acid compound and the compound B. Specifically, the nanofiber is included in a polymer layer containing one or more components selected from the group consisting of a phosphoric acid compound, a phosphonic acid compound, and a compound B from the viewpoint of further promoting the exudation of each component. More preferably, it is contained in all polymer layers containing one or more components selected from the group.

  The polymer constituting each polymer layer (for example, the first polymer layer 41, the second polymer layer 42, and the third polymer layer 43) is not particularly limited as long as the restoration agent component can be embedded. For example, a cured polymer or a thermoplastic polymer It may be. The cured polymer is usually composed of a base resin and a crosslinking agent (or curing agent). The base resin is usually a resin having a crosslinkable functional group such as a hydroxyl group, an epoxy group, a carboxyl group, a silanol group, or an alkoxysilyl group. Specific examples of the base resin include, for example, epoxy resins, acrylic resins, polyester resins, alkyd resins, fluororesins, urethane resins, and silicon-containing resins. The cross-linking agent is selected according to the base resin. Specific examples of the crosslinking agent include, for example, melamine resin, amino (urea) resin, polyisocyanate compound, block polyisocyanate compound, epoxy compound, carboxyl group-containing compound, acid anhydride group-containing compound, alkoxysilyl group-containing compound, and polyamidoamine. Etc. The polymers constituting the first polymer layer 41, the second polymer layer 42, and the third polymer layer 43 may be independently selected from the above polymers, but the protective film is formed by adjusting the leaching rate of components from each layer. From the viewpoint of sufficiently forming the polymer, the same type of polymer is preferable.

  Each polymer layer (for example, the first polymer layer 41, the second polymer layer 42, and the third polymer layer 43) is, for example, a coating solution obtained by mixing a desired restoration agent component and a polymer or a precursor thereof. It can manufacture by coating. When the polymer or its precursor has curability, it may be usually cured by heating or light irradiation. For example, in the case of curing by heating, the heating temperature and the heating time may be appropriately set according to the type of polymer. For example, when using an epoxy resin and a polyamidoamine, the heating temperature is preferably 50 to 120 ° C., particularly preferably 60 to 100 ° C., and the heating time is preferably 1 to 10 hours, particularly preferably 5 to 10 hours.

  In a polymer layer containing a phosphoric acid compound (for example, the first polymer layer, the second polymer layer or the third polymer layer), the content of the phosphoric acid compound is usually based on the total amount of the polymer layer containing the phosphoric acid compound. 0.1 to 20% by weight, preferably 0.5 to 10% by weight, and more preferably 0.5 to 5% by weight. When the phosphoric acid compound is contained in two or more polymer layers, the content of the phosphoric acid compound may be within the above range in each polymer layer.

  In the polymer layer containing the phosphonic acid compound (for example, the first polymer layer, the second polymer layer, or the third polymer layer), the content of the phosphonic acid compound is usually based on the total amount of the polymer layer containing the phosphonic acid compound. 0.1 to 20% by weight, preferably 0.5 to 10% by weight, and more preferably 0.5 to 5% by weight. When the phosphonic acid compound is contained in two or more polymer layers, the content of the phosphonic acid compound may be within the above range in each polymer layer.

  In the polymer layer containing the compound B (for example, the first polymer layer, the second polymer layer or the third polymer layer), the content of the compound B is usually 1 to 1 with respect to the total amount of the polymer layer containing the compound B. It is 20% by weight, preferably 1 to 10% by weight, more preferably 2 to 8% by weight. When compound B is contained in two or more polymer layers, the content of compound B may be in the above range in each polymer layer.

  In a polymer layer including nanofibers (for example, the first polymer layer, the second polymer layer, or the third polymer layer), the content of nanofibers is generally 0. 0 relative to the total amount of polymer layers including the nanofibers. 1 to 20% by weight, preferably 0.5 to 10% by weight, more preferably 0.5 to 5% by weight. When nanofibers are contained in two or more polymer layers, the content of nanofibers in each polymer layer may be in the above range.

  In each polymer layer (for example, the first polymer layer, the second polymer layer, or the third polymer layer), the total content of the restoration agent component is usually 0.5 to 40% by weight with respect to the total amount of each polymer layer. Yes, preferably 2-30% by weight, more preferably 5-20% by weight. The total content of the restoration agent component is, for example, the total content of a phosphoric acid compound, a phosphonic acid compound, and nanofibers contained in one polymer layer. The total content of the restorative component is also the total content of compounds B and nanofibers in one polymer layer, for example.

  The thickness of each polymer layer (for example, the first polymer layer, the second polymer layer, or the third polymer layer) is preferably as thick as possible from the viewpoint of the exudation of each component. From the viewpoint of the above, it is usually 1 to 100 μm, preferably 1 to 50 μm, more preferably 5 to 40 μm.

An insulating layer may be formed between the plating layer 2 and the polymer layer. The insulating layer means an insulating layer (particularly a polymer layer) having a volume resistivity of 10 ¹² Ω · cm or more. By forming the insulating layer, it is possible to prevent moisture that has entered from the nanofiber from coming into direct contact with the metal. The insulating layer does not contain a component of the restorative agent, and can usually be manufactured by materials and methods within the same range as the polymer layer (for example, the first polymer layer 41). The thickness of the insulating layer is usually 1 to 100 μm, and preferably 1 to 50 μm, more preferably 5 to 40 μm from the viewpoint of insulation.

  In the restorative plating substrate of the present invention, any coat layer such as a so-called hard coat layer may be formed on the outermost surface of the polymer layer.

  The repairable plating substrate of the present invention does not necessarily have to have a plating layer. When the repairable plating substrate of the present invention does not have a plating layer, it can also be referred to as a “repairable metal substrate”. The “restorable metal substrate” of the present invention has the above-described restorative plating base except that it does not have a plating layer and has the above-described multilayer polymer layer formed directly on the surface of the metal substrate 1. It is the same as the material.

(material)
The following materials were used.
・ Epoxy resin (Hypon 20 Decro Gray; manufactured by Nippon Paint Co., Ltd., curing agent = polyamidoamine, coating liquid: curing agent = 85: 15 (weight ratio))
Carbon steel plate (high tensile material) (12 mm x 12 mm) (content ratio: carbon 0.5 wt%, silicon 0.02 wt%, manganese 0.2 wt%, phosphorus 0.1 wt%, sulfur 0.1 wt% , Balance: iron)
・ Zinc sulfate (hereinafter sometimes abbreviated as “Zn”)
Cellulose nanofiber (Serish; manufactured by Daicel, average fiber length: 0.3 mm, average fiber diameter: 0.2 μm) (hereinafter sometimes abbreviated as “CNF”)
・ Sodium dihydrogen phosphate (hereinafter sometimes abbreviated as “PO ₄ ”)
ATMP sodium salt (hereinafter sometimes abbreviated as “AT”)

(Example 1)
A test piece having a schematic cross-sectional structure shown in FIG. 2 was produced. Details are as follows.

Formation of Insulating Layer 40 An epoxy resin was coated on a carbon steel plate by a bar coating method so that the coating thickness (after drying) was 20 μm, and was cured by holding at 80 ° C. for 3 hours to form the insulating layer 40.

-Formation of the 1st polymer layer 41 Zinc sulfate and the cellulose nanofiber were mixed with the spatula, the mixture was added to the epoxy resin, and it stirred and deaerated with the stirrer, and prepared the coating liquid. The contents of zinc sulfate and cellulose nanofibers were 4.6% by weight and 1.0% by weight, respectively, based on the total amount.
The coating liquid was coated on the insulating layer by a bar coating method so that the coating thickness (after drying) was 20 μm, and was cured by holding at 80 ° C. for 3 hours to form the first polymer layer 41.

-Formation of second polymer layer 42 Sodium dihydrogen phosphate, ATMP sodium salt and cellulose nanofiber were mixed with a spatula, the mixture was added to an epoxy resin, and stirred and defoamed with a stirrer to prepare a coating solution. . The contents of sodium dihydrogen phosphate, ATMP sodium salt, and cellulose nanofiber were 1.9 wt%, 1.5 wt%, and 1.0 wt%, respectively, based on the total amount.
The coating solution was coated on the first polymer layer by a bar coating method so that the coating thickness (after drying) was 20 μm, and was cured by holding at 80 ° C. for 3 hours to form the second polymer layer 42.

-Formation of the topcoat layer 60 The topcoat layer 60 was formed in the 2nd polymer layer 42 by the method similar to the formation method of the insulating layer 40. The top coat layer 60 is a layer for preventing elution of the repair agent from other than scratches to be formed later.

-Formation of scratches A scratch (scratch) having a length of 4 mm and a depth of 30 µm (depth only with a carbon steel plate) was applied to the prepared test piece with a load of 500 g using a scratch tester.

(Example 2)
A test piece having a schematic cross-sectional structure shown in FIG. 3 was produced. Details are as follows.
A test piece was produced in the same manner as in Example 1 except that cellulose nanofibers were not used to form the first polymer layer 41 and the second polymer layer 42.

(Comparative Example 1)
A test piece having a schematic cross-sectional structure shown in FIG. 4 was produced. Details are as follows.
A test piece was produced in the same manner as in Example 1 except that the second polymer layer 42 was not formed and that the following coating liquid was used to form the first polymer layer 41.
-Coating liquid of first polymer layer 41 Zinc sulfate, sodium dihydrogen phosphate, ATMP sodium salt and cellulose nanofiber are mixed with a spatula, the mixture is added to an epoxy resin, and the mixture is stirred and degassed with a stirrer. A liquid was prepared. The contents of zinc sulfate, sodium dihydrogen phosphate, ATMP sodium salt and cellulose nanofiber are 4.6% by weight, 1.9% by weight, 1.5% by weight and 1.0% by weight, respectively, based on the total amount. there were.

(Comparative Example 2)
A test piece having a schematic cross-sectional structure shown in FIG. 5 was produced. Details are as follows.
A test piece was produced in the same manner as in Comparative Example 1 except that cellulose nanofibers were not used to form the first polymer layer 41.

(Reference Example 1)
A test piece having a schematic cross-sectional structure shown in FIG. 6 was produced. Details are as follows.
A test piece was produced in the same manner as in Comparative Example 1 except that zinc sulfate, sodium dihydrogen phosphate, ATMP sodium salt, and cellulose nanofiber were not used to form the first polymer layer 41.

(Example 3)
A test piece having a schematic cross-sectional structure shown in FIG. 7 was produced. Details are as follows.
The same as in Example 1 except that the coating liquid for the second polymer layer 42 was used for forming the first polymer layer 41 and the coating liquid for the first polymer layer 41 was used for forming the second polymer layer 42. The test piece was manufactured by the method.

Example 4
A test piece having a cross-sectional structure similar to the schematic cross-sectional structure shown in FIG. 1D was manufactured except that an insulating layer was formed instead of the plating layer 2 and scratches were applied. Details are as follows.

-Formation of an insulating layer By the method similar to the formation method of the insulating layer of Example 1, the insulating layer was formed in the carbon steel plate.

-Formation of the 1st polymer layer 41 Zinc sulfate and the cellulose nanofiber were mixed with the spatula, the mixture was added to the epoxy resin, and it stirred and deaerated with the stirrer, and prepared the coating liquid. The contents of zinc sulfate and cellulose nanofibers were 4.6% by weight and 1.0% by weight, respectively, based on the total amount.
The coating liquid was coated on the insulating layer by a bar coating method so that the coating thickness (after drying) was 20 μm, and was cured by holding at 80 ° C. for 3 hours to form the first polymer layer 41.

-Formation of second polymer layer 42 ATMP sodium salt and cellulose nanofiber were mixed with a spatula, the mixture was added to an epoxy resin, and stirred and defoamed with a stirrer to prepare a coating solution. The contents of ATMP sodium salt and cellulose nanofiber were 1.5% by weight and 1.0% by weight, respectively, based on the total amount.
The coating solution was coated on the first polymer layer by a bar coating method so that the coating thickness (after drying) was 20 μm, and was cured by holding at 80 ° C. for 3 hours to form the second polymer layer 42.

-Formation of third polymer layer 43 Sodium dihydrogen phosphate and cellulose nanofibers were mixed with a spatula, the mixture was added to an epoxy resin, and stirred and defoamed with a stirrer to prepare a coating solution. The contents of sodium dihydrogen phosphate and cellulose nanofibers were 1.9 wt% and 1.0 wt%, respectively, based on the total amount.
The coating solution was coated on the second polymer layer by a bar coating method so that the coating thickness (after drying) was 20 μm, and was cured by holding at 80 ° C. for 3 hours to form a third polymer layer 43.

-Formation of topcoat layer The topcoat layer was formed in the 3rd polymer layer 43 by the method similar to the formation method of the topcoat layer of Example 1. FIG.

-Formation of scratches A scratch (scratch) having a length of 4 mm and a depth of 30 µm (depth only with a carbon steel plate) was applied to the prepared test piece with a load of 500 g using a scratch tester.

(Evaluation 1)
In the electrochemical measuring apparatus 50 shown in FIG. 8, the test piece is immersed in the corrosive solution 52 as the working electrode 51, the AC impedance is measured for 48 hours, the change in polarization resistance with time is measured, and the self-repairability of the test piece is measured. evaluated. As the corrosive solution 52, 0.5% by weight of saline was kept at 35 ° C. and saturated with air. A platinum electrode was used as the counter electrode 53, and an Ag / AgCl electrode was used as the reference electrode 54. 55 is a potentiostat and 56 is a frequency response analyzer (FRA).

  9A to 9B show changes with time in the polarization resistance of each test piece. In these figures, the vertical axis represents polarization resistance and the horizontal axis represents immersion time. This indicates that the higher the polarization resistance, the less likely the corrosion reaction occurs at the scratch. In addition, the graph which shows a time-dependent change of the test piece of Example 4 was abbreviate | omitted. For Example 4, the average value of polarization resistance and its error range (maximum value and minimum value) in Evaluation 2 described later are shown in FIG.

  When only epoxy resin was coated in Reference Example 1 (Plain), high polarization resistance was exhibited at the initial stage of immersion, but the resistance value gradually decreased thereafter. It is thought that corrosion has progressed on the exposed surface of the steel plate at the scratch.

From the comparison between Examples 1, 3 and 4 and Comparative Example 1, and the comparison between Example 2 and Comparative Example 2, the polymer layer is made into two or more layers, a layer containing Zn, and a single layer containing PO ₄ and AT It became clear that by dividing into the above layers, the polarization resistance increased and corrosion was more sufficiently suppressed. This is because when the components such as Zn, PO ₄ and AT are contained in one polymer layer (Comparative Examples 1 and 2), the reaction of the reaction formulas (I) and (II) is performed in one polymer layer. It is thought that the polarization resistance did not sufficiently increase because the exudation and release of each component to the wound were prevented. On the other hand, when Zn, PO ₄ and AT are separately contained in a layer containing Zn and one or more layers containing PO ₄ and AT, each component exudes smoothly from the layer. Since the reactions (I) and (II) occurred and a protective film (restoration film) was more effectively formed on the exposed surface of the steel sheet at the scratched part, it is considered that corrosion was more sufficiently suppressed.

From the comparison between Example 1 and Example 3, the corrosion suppression effect is further improved by making the polymer layer two or more layers and positioning the Zn-containing layer below the one or more layers containing PO ₄ and AT. It became clear that it would be much higher. As shown in FIG. 10, a Zn-rich layer that is more effective in inhibiting corrosion is more easily formed on the exposed surface of the metal substrate than a layer made of a composite product of Zn + PO ₄ + AT, and therefore, the corrosion-inhibiting effect is more effective. It is thought that it will be much higher.

In Example 1, when a scanning electron microscope (SEM) photograph of the exposed surface of the steel sheet in the scratched part after 48 hours of immersion time was taken (FIG. 11A), a product having a diameter of about 1 μm covered the exposed surface. Was confirmed. In addition, an element mapping image was obtained by an energy dispersive X-ray analyzer (EDS). 11B to 11F are mapping images of Fe, Zn, P, O, and N elements in FIG. 11A, respectively. FIG. 11G is an enlarged photograph of the encircled portion by the white line in FIG. 11A. FIG. 11H is an enlarged photograph of a portion surrounded by a white line in FIG. 11B. FIG. 11I is an enlarged photograph of a portion surrounded by a white line in FIG. 11E. FIG. 11J is an enlarged photograph of a portion surrounded by a white line in FIG. 11C. FIG. 11K is an enlarged photograph of the encircled portion by the white line in FIG. 11D.
11A to 11K (actual: color copy) and photographs (actual: color copy) of FIGS. 12A to 12F, 13A to 13F, and 14A to 14E described later are used as reference material (reference photograph) 1. Submit in the property submission form.

From FIGS. 11G, 11H, and 11I, Fe and O are detected in different regions. This shows that the detected Fe is derived from the metal surface.
From FIGS. 11I, 11J, and 11K, Zn, P, and O are detected in the same region. This shows that the detected Zn, P and O are derived from the reaction products of the reaction formulas (I) and (II).

  In Example 1, a scanning electron microscope (SEM) photograph of the exposed surface of the steel sheet in the scratched part when the immersion time was 3 hours was taken (FIG. 12A). In addition, an element mapping image was obtained by an energy dispersive X-ray analyzer (EDS). 12B to 12F are mapping images of Fe, Zn, O, P, and N elements in FIG. 12A, respectively.

  In Reference Example 1, a scanning electron microscope (SEM) photograph of the exposed surface of the steel sheet in the scratched part when the immersion time was 48 hours was taken (FIG. 13A). In addition, an element mapping image was obtained by an energy dispersive X-ray analyzer (EDS). 13B to 13F are mapping images of the Fe, Zn, O, P, and N elements in FIG. 13A, respectively.

  In Example 3, a scanning electron microscope (SEM) photograph of the exposed surface of the steel sheet at the scratched part when the immersion time was 48 hours was taken (FIG. 14A). In addition, an element mapping image was obtained by an energy dispersive X-ray analyzer (EDS). 14B to 14E are mapping images of Fe, Zn, O, and P elements in FIG. 14A, respectively.

(Evaluation 2)
The reproducibility was verified for Examples 1, 3 and 4, Comparative Example 1 and Reference Example 1. In each of the examples / comparative examples / reference examples, three or more test pieces were prepared, and the alternating current impedance was measured for 48 hours by the same method as in Evaluation 1, and the polarization resistance was measured at 48 hours of immersion. The average value of the polarization resistance and its error range (maximum value and minimum value) are shown in the graph of FIG. The error bar in FIG. 15 represents the error range. In FIG. 15, the vertical axis represents polarization resistance (Ω · cm ² ).

  The restorative plating base material of the present invention is useful in the field of articles that are required to suppress corrosion (for example, metal products such as automobiles, home appliances, and metal building materials).

1: Metal base material 2: Plating layer 10: Plating base material 13: Defect (scratch)
14: Protective film 40: Insulating layer 41: First polymer layer 42: Second polymer layer 43: Third polymer layer

Claims (13)

The surface of the metal substrate has a plating layer containing metal A having a higher ionization tendency than the metal constituting the metal substrate, and two or more polymer layers formed on the plating layer, A repairable plating base material comprising a compound containing two or more polymer layers containing a phosphoric acid compound, a phosphonic acid compound and a metal B having a higher ionization tendency than the metal constituting the metal base material,
The compound containing metal B having a high ionization tendency is contained in a polymer layer different from the polymer layer containing at least one of the phosphoric acid compound and the phosphonic acid compound among the two or more polymer layers. Repairable plating base material. The phosphoric acid compound and the phosphonic acid compound are included in a weight ratio of 10/90 to 90/10,
2. The repair according to claim 1, wherein the compound containing metal B having a high ionization tendency is included in an amount of 10 to 400 parts by weight with respect to 100 parts by weight of the total amount of the phosphoric acid compound and the phosphonic acid compound. Plating substrate. The plating substrate has a defect reaching the metal substrate;
The restorative plating base material according to claim 1 or 2, wherein a protective film is formed on a surface of the metal base material on which the metals A and B having a high ionization tendency, the phosphoric acid compound and the phosphonic acid compound are exposed. A first polymer layer and a second polymer layer are sequentially laminated on the plating layer,
The compound containing metal B having a high ionization tendency is included in one polymer layer of the first polymer layer and the second polymer layer,
The repairable plating substrate according to any one of claims 1 to 3, wherein the phosphoric acid compound and the phosphonic acid compound are contained in the other polymer layer. The compound containing metal B having a high ionization tendency is included in the first polymer layer,
The repairable plating base material according to claim 4, wherein the phosphoric acid compound and the phosphonic acid compound are contained in the second polymer layer. Three polymer layers are formed on the plating layer,
The compound containing metal B having a high ionization tendency is included in one polymer layer among the three polymer layers,
The phosphoric acid compound and the phosphonic acid compound are respectively contained in different polymer layers among the two polymer layers other than the polymer layer containing the compound containing the metal B having a high ionization tendency. The repairable plating base material in any one of 1-3. A first polymer layer, a second polymer layer, and a third polymer layer are sequentially laminated on the plating layer,
The compound containing metal B having a high ionization tendency is included in the first polymer layer,
The phosphoric acid compound is contained in one polymer layer of the second polymer layer or the third polymer layer,
The repairable plating base material according to claim 6, wherein the phosphonic acid compound is contained in the other polymer layer. In the polymer layer including the compound containing the metal B having a high ionization tendency, the compound containing the metal B having the high ionization tendency is included in an amount of 1 to 20% by weight with respect to the total amount of the polymer layer.
In the polymer layer containing the phosphoric acid compound, the phosphoric acid compound is contained in an amount of 0.1 to 20% by weight based on the total amount of the polymer layer.
The restoration | repair in any one of Claims 1-7 in which the said phosphonic acid compound is contained in 0.1-20 weight% with respect to this polymer layer whole quantity in the polymer layer in which the said phosphonic acid compound is contained. Plating substrate. The phosphate compound is an inorganic phosphate compound,
The repairable plating base material according to any one of claims 1 to 8, wherein the phosphonic acid compound is an organic phosphonic acid compound. The inorganic phosphate compound is one or more compounds selected from the group consisting of phosphoric acid (H ₃ PO ₄ ) and phosphate,
The repairable plating base material according to claim 9, wherein the organic phosphonic acid compound is one or more compounds selected from the group consisting of a nitrogen-containing phosphonic acid compound and a salt thereof. The phosphate is a salt of a first phosphate ion (H ₂ PO ₄ ⁻ ), a second phosphate ion (HPO ₄ ²⁻ ) or a third phosphate ion (PO ₄ ³⁻ ) and a cation. Yes,
The cation is at least one ion selected from the group consisting of a monovalent metal ion, a divalent metal ion, a trivalent metal ion and an ammonium ion;
The repairable plating base material according to claim 10, wherein the nitrogen-containing phosphonic acid compound is a phosphono group-containing amine. The metal substrate is a steel plate;
The metals A and B having a high ionization tendency are each independently one or more metals selected from the group consisting of zinc, aluminum, magnesium and zirconium;
The repairable plating substrate according to any one of claims 1 to 11, wherein the plating layer is formed by an impact plating method. The plated layer is a galvanized layer;
The compound containing metal B having a high ionization tendency is selected from the group consisting of zinc sulfate, iron sulfate, nickel sulfate, zirconium sulfate, zinc nitrate, aluminum sulfate, aluminum nitrate, magnesium sulfate, and magnesium nitrate. The repairable plating base material in any one of 1-12.