Metal protective laminate

Abstract

To provide a metal protective laminate in which a coating having superior gas barrier performance is formed on a metal substrate uniformly and smoothly with strong adhesion, the laminate exhibiting excellent corrosion resistance.SOLUTION: A metal protective laminate is provided, the laminate having a barrier coating containing at least a phosphate on a metal substrate.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a metal protective laminate comprising a barrier coating film formed on a metal substrate, and more particularly to a metal protective laminate having a barrier coating film uniformly applied to a metal substrate and having excellent corrosion resistance. [Background technology]

[0002] Coated metal sheets, which are metal sheets such as aluminum coated with a protective layer of an organic resin or the like, have long been known as metal laminate materials. These coated metal sheets can be used as they are, or cans can be formed into seamless cans for filling beverages or the like by drawing or drawing and ironing, or can lids, battery exterior materials, and the like by punching or press forming. The metal sheets used in the coated metal sheets for such applications are generally surface-treated metal sheets that have been subjected to a surface treatment such as a chemical conversion treatment in order to improve corrosion resistance and ensure adhesion when a protective layer such as a coating is further applied. A widely used surface treatment is chromate phosphate treatment.

[0003] However, the surface preparation using chromate phosphate treatment has the problem that the organic resin coating peels off when subjected to severe processing, so it has been proposed to perform chemical conversion treatment with a chromium-containing solution, followed by chemical conversion treatment with a zirconium-containing solution to form a coating, and then paint on top of that (Patent Document 1).

[0004] A laminate having excellent oxygen barrier properties and water vapor barrier properties is provided, which has a barrier layer (Y) containing a reaction product (R) obtained by reacting at least a metal oxide (A) with a phosphorus compound (B), and has a viscosity of 800 to 1400 cm -1 The fraction (n) at which the infrared absorption is maximum in the infrared absorption spectrum of the layer (Y) in the range 1 ) is 1080~1130cm -1and a laminate in which the metal atom (M) constituting the metal oxide (A) is aluminum (Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 8-19533 [Patent Document 2] Patent No. 4961054 Summary of the Invention [Problem to be solved by the invention]

[0006] The coating film obtained by the chemical conversion treatment described in Patent Document 1 is difficult to form uniformly on a metal substrate and difficult to shield the underlying metal surface. Therefore, when placed in a corrosive environment, corrosive gases or liquids may come into contact with the metal surface, potentially causing corrosion of the metal substrate, making it difficult to achieve sufficient corrosion resistance. Furthermore, because chromate phosphate treatment uses a chromium compound, there is a growing demand for non-chromium surface treatments from an environmental protection perspective. Furthermore, because the surface treatment film formed by chromate phosphate treatment is a hard inorganic film, it is prone to cracking during molding or when subjected to external impact, and it also has poor processing followability and impact resistance.

[0007] Furthermore, the laminate described in Patent Document 2 also describes metal as a substrate (X) to which layer (Y), which is a barrier layer, can be applied. However, there are no examples of this substrate being actually used, and it is unclear whether similar barrier properties and adhesion can be exhibited to metal. In addition, there are concerns about the stability of layer (Y) against permeating gases such as acids and alkalis, and against contact with corrosive substances, and there is a risk that sufficient corrosion resistance may not be exhibited.

[0008] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a metal protective laminate having excellent corrosion resistance, in which a coating having excellent gas barrier properties is formed uniformly, smoothly and with good adhesion on a metal substrate. Another object of the present invention is to provide a resin-coated metal protective laminate in which a coating having excellent oxygen barrier properties and water vapor barrier properties is formed using a gas barrier coating composition containing a metal oxide and a phosphate, and which has excellent corrosion resistance, as well as excellent adhesion to an organic resin coating formed on the barrier coating and to the metal substrate itself. [Means for solving the problem]

[0009] According to the present invention, there is provided a metal protective laminate characterized by having, on a metal substrate, a barrier coating film containing at least a phosphate.

[0010] In the metal protection laminate of the present invention, (1) The barrier coating film is made of a reaction product obtained by reacting a metal oxide with at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, a metal hydroxide, and an amino acid salt, and a phosphoric acid compound or a sulfuric acid compound. (2) The metal species of the metal alkoxide and metal hydroxide is at least one of aluminum, titanium, iron, and zirconium; (3) The metal alkoxide is at least one of methoxide, ethoxide, propoxide, isopropoxide, butoxide, isobutoxide, sec-butoxide, and tert-butoxide; (4) The metal alkoxide is aluminum isopropoxide. (5) The metal hydroxide is aluminum hydroxide. (7) The amino acid salt is aluminum glycinate. (8) The metal oxide is zirconium oxide or aluminum oxide. (9) The metal oxide is nanoparticles having a particle diameter of 100 nm or less. (10) The metal oxide is a crystalline zirconium oxide. (11) The amino acid salt is aluminum glycinate. (12) The phosphoric acid compound is at least one of orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, and cyclic polyphosphoric acid; (13) The barrier coating film has an infrared absorption spectrum of 980 to 1100 cm -1 The infrared absorption has a maximum absorption peak in the range of (14) The barrier coating film has a Zr (Zr-kα) to P (P-kα) content ratio (P / Zr) in the range of 0.40 to 2.00 and a Zr (Zr-kα) to P (P-kα) content ratio (Al / Zr) in the range of 0.05 to 0.55, as measured by fluorescent X-rays. (15) The metal substrate is made of any one of aluminum, aluminum alloy, iron, copper, and titanium. (16) The metal substrate is a metal molded body or a metal foil. is preferred.

[0011] The present invention also provides a resin-coated metal protection laminate, characterized in that a resin coating layer is formed on the barrier coating film of the above metal protection laminate.

[0012] The present invention further provides a coating composition for protecting metal substrates, which comprises a metal oxide, at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, a metal hydroxide, and an amino acid salt, and a phosphate compound or a sulfate compound. [Effects of the Invention]

[0013] In the metal protective laminate of the present invention, the metal substrate is coated with a barrier coating film that has excellent oxygen barrier properties and water vapor barrier properties, and therefore, it is possible to block the permeation of not only oxygen and water vapor, but also corrosive liquids and corrosive gases such as hydrogen sulfide from the contents, thereby significantly improving the corrosion resistance of the metal material. Furthermore, this barrier coating film is formed on the surface of the metal substrate in a smooth and uniform manner, and has excellent adhesion to the metal substrate, so that the excellent barrier properties of the barrier coating film can be efficiently exhibited. Furthermore, in a resin-coated metal protection laminate obtained by forming a resin coating on this barrier coating film, the barrier layer has excellent adhesion to the resin coating or adhesive layer, which can also improve adhesion between the metal substrate and the resin coating. Furthermore, since the barrier coating film contains a phosphoric acid compound, when an aluminum plate is used as the metal substrate, the adhesion between the metal substrate and the barrier layer is significantly improved due to the reaction between the phosphoric acid and aluminum. DETAILED DESCRIPTION OF THE INVENTION

[0014] An important feature of the metal protective laminate of the present invention is that it has, on a metal substrate, a barrier coating film containing at least a phosphate. As described above, the presence of such a barrier coating film makes it possible to block permeating gases such as oxygen from the metal substrate, thereby making it possible to significantly improve the corrosion resistance of the metal substrate. Furthermore, the formation of a barrier coating film makes it possible to significantly improve interlayer adhesion when a resin coating is formed. Furthermore, this barrier coating film has excellent adhesion to metal substrates because the phosphate compound also reacts with the metal of the metal substrate.

[0015] (Barrier coating film) The barrier coating film is preferably a barrier coating film containing at least a phosphate, and particularly preferably a reaction product obtained by reacting a metal oxide with at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, a metal hydroxide, and an amino acid salt, and a phosphoric acid compound or a sulfate compound. Specifically, a metal phosphate is formed as the reaction product, and a dense crosslinked structure is formed by crosslinking the metal oxide and the phosphate compound. Furthermore, the metal alkoxide or the like reacts with phosphoric acid to form a metal phosphate, which is incorporated into the crosslinked structure and functions as a binder between the metal oxide particles, resulting in the formation of a defect-free coating film. This, combined with the uniform and dense crosslinked structure, allows for the development of superior oxygen barrier properties and water vapor barrier properties. Furthermore, the use of zirconium oxide as the metal oxide allows the formation of a coating film that is stable against acids and alkalis, and furthermore, exhibits excellent oxygen barrier properties and water vapor barrier properties.

[0016] [Metal oxides] In the preferred barrier coating film described above, the metal oxide is preferably an oxide of a divalent or higher metal atom, and examples thereof include, but are not limited to, oxides of magnesium, calcium, iron, zinc, aluminum, silicon, titanium, zirconium, etc., and zirconium oxide is particularly preferred. As used herein, the term "metal oxide" refers to a metal oxide containing, as its main component, a structure represented by MOM, where M represents a metal atom and O represents an oxygen atom. Zirconium oxide contains Zr and O as component elements, and amorphous zirconium oxide contains zirconium hydroxide (Zr(OH)4) and / or zirconyl hydroxide (ZrO(OH)2) as the main component, while crystalline zirconium oxide contains hydrated zirconium oxide (ZrO2·xH2O) and / or zirconium oxide (ZrO2) as the main component. The term "main component" refers to a component that accounts for 50% or more of the total. The crystallinity of zirconium oxide and zirconium oxide that has been applied to a gas barrier coating can be evaluated by identifying the X-ray peaks specific to crystalline zirconium using a conventionally known X-ray structural diffractometer. In the present invention, either crystalline or amorphous zirconium oxide (zirconia) can be used as the zirconium oxide.

[0017] Zirconium oxide is used in the form of a sol in which zirconium oxide particles are used as a dispersoid and an inorganic acid such as nitric acid is blended as a stabilizer. In the present invention, however, in order to prevent the volatilization of the inorganic acid during coating film formation due to the inclusion of the inorganic acid, it is preferable to use a zirconium oxide sol in which a carbonate, ammonium carbonate, an organic dispersant, or the like is used instead of an inorganic acid such as nitric acid. Furthermore, the binder component contains at least one of a metal alkoxide, a hydrolysate of a metal alkoxide, and a metal hydroxide, which are capable of providing many hydroxyl groups available for reaction with phosphoric acid. Therefore, just as with the use of amorphous zirconium oxide, even when crystalline zirconium oxide is used, it is possible to achieve both oxygen barrier properties and water vapor barrier properties equivalent to those achieved when amorphous zirconium oxide with many hydroxyl groups is used.

[0018] Furthermore, it is desirable that the zirconium oxide particles be nanoparticles with an average primary particle size (D50) of 100 nm or less, preferably 50 nm or less, and more preferably 30 nm or less, which allows the formation of a uniform coating film with excellent transparency. The average particle size (D50) is the volume-average particle size measured by laser diffraction / scattering, and D50 is the 50% value in the volume-based particle size distribution. Using such fine particle-type zirconium oxide as a raw material allows the development of excellent transparency.

[0019] [Metal alkoxide or its hydrolyzate] Metal alkoxides are generally represented by the following formula (1). M n+ (OR)n - ···(1) In the formula, R represents an organic group having 1 to 8 carbon atoms, M represents a metal atom, and n is an integer of 1 or more. Represents.

[0020] In the present invention, it is preferable that the metal atom M in the above formula (1) is any one of aluminum, titanium, iron, and zirconium. In the above formula (1), the organic group R is preferably any one of a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. In the present invention, as described above, the metal alkoxide is preferably at least one metal alkoxide selected from methoxide, ethoxide, propoxide, isopropoxide, butoxide, isobutoxide, sec-butoxide, and tert-butoxide, and among these, aluminum isopropoxide can be preferably used.

[0021] [Metal hydroxide] Metal hydroxides are generally represented by the following formula (2). M n+ (OH)n - ···(2) In the formula, H represents a hydrogen atom, M represents a metal atom, and n represents an integer of 1 or more. The metal hydroxide is preferably any of the hydroxides of aluminum, titanium, iron, and zirconium listed as examples of metal alkoxides, and among these, aluminum hydroxide is preferably used.

[0022] [Amino acid salts] The amino acid salt can be suitably composed of a polyvalent metal ion and an amino acid compound. The polyvalent metal ions eluted from the amino acid salt dissolved by phosphoric acid compensate for the lack of metal ions in the binder between particles in the crosslinked structure of metal oxide and phosphoric acid, thereby further improving the oxygen gas barrier property and water vapor barrier property. The polyvalent metal ion in the amino acid salt is not particularly limited as long as it can provide a polyvalent metal ion capable of crosslinking carboxyl groups. Examples of polyvalent metal ions include alkaline earth metals (magnesium Mg, calcium Ca, strontium Sr, barium Ba, etc.), metals in Group 8 of the periodic table (iron Fe, ruthenium Ru, etc.), metals in Group 11 of the periodic table (copper Cu, etc.), metals in Group 12 of the periodic table (zinc Zn, etc.), and metals in Group 13 of the periodic table (aluminum Al, etc.). Divalent to trivalent ions are particularly preferred, and aluminum ions are preferred. The above metal ions can be used alone or in combination.

[0023] Examples of amino acid compounds capable of forming amino acid salts with polyvalent metal ions include α-amino acids such as glycine, alanine, serine, tryptophan, lysine, arginine, glutamic acid, and aspartic acid, β-amino acids such as β-alanine, γ-amino acids such as γ-aminobutyric acid, and amino acid polymers. One or more of these can be used in combination, and glycine and aspartic acid are particularly preferred. In the present invention, aluminum glycinate is particularly suitable as the amino acid salt.

[0024] [Phosphate compounds] Phosphoric acid compounds include orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, phosphorous acid, phosphonic acid, and their derivatives. Specific examples of polyphosphoric acid include pyrophosphoric acid, triphosphoric acid, and polyphosphoric acid condensed with four or more phosphoric acids. Examples of the above derivatives include salts, (partial) ester compounds, halides (e.g., chlorides), and dehydrates (e.g., diphosphorus pentoxide) of orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, phosphorous acid, and phosphonic acid. Examples of phosphonic acid derivatives include compounds in which the hydrogen atom directly bonded to the phosphorus atom of phosphonic acid (HP(=O)(OH)2) is substituted with an alkyl group that may have various functional groups (e.g., nitrilotris(methylenephosphonic acid), N,N,N',N'-ethylenediaminetetrakis(methylenephosphonic acid)), as well as salts, (partial) ester compounds, halides, and dehydrates thereof. Furthermore, organic polymers containing phosphorus atoms, such as phosphorylated starch, can also be used. These phosphoric acid compounds can be used alone or in combination of two or more. In the present invention, it is particularly preferable to use at least one of orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, and cyclic polyphosphoric acid.

[0025] [Sulfuric acid compounds] In the present invention, examples of sulfate compounds that can be used instead of the above-mentioned phosphoric acid compounds to react with metal oxides to form dense coating films include compounds selected from the group consisting of sulfuric acid, sulfates, sulfate esters, alkyl sulfates, polyoxyethylene alkyl ether sulfates, and salts thereof. These sulfate compounds can be used alone or in combination of two or more. In the present invention, sulfuric acid can be particularly preferably used.

[0026] [Coating film properties] The barrier coating film in the metal protection laminate of the present invention has a wavelength of 800 to 1400 cm by FT-IR measurement of the coating film alone. -1 In the infrared absorption spectrum in the range of 980 to 1100 cm -1 The infrared absorption peak is in the range of 1000 to 10000. Furthermore, in the barrier coating film, the content ratio (P / M) of M (M-kα) of a metal oxide or metal alkoxide, etc., measured by X-ray fluorescence measurement to P (P-kα) of a phosphate compound, etc., measured by X-ray fluorescence measurement, is preferably in the range of 0.40 to 2.00, particularly in the range of 0.52 to 1.91, when zirconium oxide is used as the metal oxide, phosphoric acid as the phosphate compound, etc., and aluminum isopropoxide as the metal alkoxide, etc., and the content ratio (P / Zr) of Zr (Zr-kα) of zirconium oxide, measured by X-ray fluorescence measurement to P (P-kα) of the phosphate compound, etc., measured by X-ray fluorescence measurement, is preferably in the range of 0.40 to 2.00, particularly in the range of 0.52 to 1.91. When the content ratio is within the above range, the phosphate compound reacts efficiently with the hydroxyl groups of the metal oxide in the coating film, neither too much nor too little, making it possible to form a uniform and dense coating film and achieving excellent oxygen barrier properties and water vapor barrier properties. That is, if the content ratio as determined by fluorescent X-ray measurement is less than the above range and there is an insufficient amount of phosphate compound, the bonding between the metal oxide particles will be insufficient and the amount of hydroxyl groups present on the surfaces of the metal oxide particles will increase, which could result in reduced oxygen barrier properties and water vapor barrier properties. On the other hand, if the content ratio as determined by fluorescent X-ray measurement is greater than the above range and there is an excess of phosphate compound, the amount of hydroxyl groups derived from the phosphate groups will increase, which could also result in reduced oxygen barrier properties and water vapor barrier properties.

[0027] Furthermore, when using zirconium oxide as the metal oxide, phosphoric acid as the phosphate compound, etc., and aluminum isopropoxide as the metal alkoxide, etc., it is preferable that the content ratio (Al / Zr) of Zr (Zr-kα) determined by X-ray fluorescence measurement of zirconium oxide to Al (Al-kα) determined by X-ray fluorescence measurement of aluminum isopropoxide is in the range of 0.05 to 0.55, particularly in the range of 0.09 to 0.43. When the content ratio is within the above range, it becomes possible to exhibit the above-described effects of the metal alkoxide and the like without impairing the dense cross-linked structure of the zirconium oxide and the phosphate compound, and it becomes possible to exhibit excellent oxygen barrier property and water vapor barrier property.

[0028] (Coating composition for protecting metal substrates) The coating composition for forming the barrier coating film in the metal protective laminate of the present invention described above may be either an aqueous or solvent-based composition, as long as it contains the metal oxide, at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, a metal hydroxide, and an amino acid salt, and a phosphoric acid compound or a sulfuric acid compound, as described above, but is preferably an aqueous composition. In this coating composition, it is desirable to use a sol containing metal oxide fine particles as the dispersoid as the metal oxide. Furthermore, it is preferable to use a sol containing metal oxide fine particles as the dispersoid that does not contain a volatile acid as a stabilizer, in order to suppress the adverse effects of acid generation on equipment and the working environment. For the above reasons, it is desirable not to use, as a deflocculating agent, volatile acids such as nitric acid, hydrochloric acid, and acetic acid, which have been used to obtain dispersions with excellent transparency and viscosity stability.

[0029] The coating composition is prepared by mixing a metal oxide, a phosphate compound, etc., and a metal alkoxide, etc. in a solvent capable of dissolving the phosphate compound, etc. and the metal alkoxide, etc. As such an aqueous medium, conventionally known aqueous solvents such as distilled water, ion-exchanged water, and pure water can be used. Similar to known aqueous compositions, organic solvents such as alcohols, polyhydric alcohols, their derivatives, and ketones can be contained. When such a cosolvent is used, it can be contained in an amount of 1 to 90 wt % of the aqueous solvent in the aqueous composition. By including a solvent in the above range, film-forming performance is improved. Preferred organic solvents are those having amphiphilic properties, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, butyl cellosolve, propylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, 3-methyl-3-methoxybutanol, acetone, and methyl ethyl ketone.

[0030] The coating composition can be prepared by a commonly known dispersion treatment. Examples of dispersion treatment methods include pulverization of fine particles by cavitation using an ultrasonic homogenizer, mechanical dispersion using a disperser with rotating blades, and dispersion using a mill with glass or zirconia beads. These coating fine dispersion treatments can be suitably used in the present invention.

[0031] In the coating composition, a phosphate compound or the like and a metal alkoxide or the like can be added to the metal oxide within a range that does not impair the oxygen barrier property and water vapor barrier property. The amount of the phosphate compound or the like to be added varies depending on the type of phosphate compound or the like used and cannot be generally specified. However, when zirconium oxide is used as the metal oxide, phosphoric acid as the phosphate compound or the like, and aluminum isopropoxide as the metal alkoxide or the like, it is preferable to blend in an amount of 53 to 86 parts by mass, and particularly 53 to 64 parts by mass, of the nonvolatile content of phosphoric acid per 100 parts by mass of the solid content of zirconium oxide.

[0032] The amount of metal alkoxide or the like to be added varies depending on the type of metal alkoxide or the like used and cannot be generally defined. However, when zirconium oxide is used as the metal oxide, phosphoric acid is used as the phosphate compound or the like, and aluminum isopropoxide is used as the metal alkoxide or the like, it is preferable to add aluminum isopropoxide in an amount of 45 to 49 parts by mass per 100 parts by mass of the solid content of zirconium oxide. If the amount added is less than the above range, the effect obtained by adding a metal alkoxide or the like will not be as sufficient as when it is within the above range, and if the amount added is greater than the above range, not only will no further effect be obtained, but there is also a risk of defects in the barrier structure of the coating film as compared to when it is within the above range.

[0033] The coating composition preferably contains a catalyst capable of promoting the reaction between the metal oxide or metal alkoxide used and the phosphoric acid compound, etc. This promotes the crosslinking reaction of the coating composition, making it possible to reduce the heating temperature and heating time required for forming a coating film. Examples of such catalysts include acid catalysts such as paratoluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, and cumenesulfonic acid, as well as amine neutralization products of these acids. Of these, paratoluenesulfonic acid is particularly preferred. The acid catalyst is preferably contained in an amount of 0.1 to 10 parts by mass, particularly 1 to 3 parts by mass, per 100 parts by mass of the solid content of zirconium oxide. In addition to the above components, the gas barrier coating composition may also contain crosslinking agents, metal complexes, condensation accelerators, polymeric compounds, fillers, plasticizers, antioxidants, ultraviolet absorbers, flame retardants, antifoaming agents, colorants, etc.

[0034] (Metal protective laminate) The metal protective laminate of the present invention is a laminate comprising a metal substrate and the above-described barrier coating film formed on at least one surface thereof. The thickness of the barrier coating film in the metal protective laminate cannot be generally determined depending on the thickness of the substrate, but it is generally in the range of 0.1 to 30.0 g / m2 in terms of the solid weight of the coating film. 2 , especially 0.3 to 8.0 g / m 2 It is preferable to coat the metal substrate so that the thickness is within the range. If the thickness is thinner than the above range, it is difficult to impart sufficient corrosion resistance to the metal substrate, while if the thickness is thicker than the above range, further improvement in corrosion resistance cannot be expected and the cost may be poor. Furthermore, if the metal substrate is flexible, such as a foil, the flexibility may be impaired. The metal constituting the metal substrate is not limited to these, but aluminum, aluminum alloys, iron, copper, titanium, etc. can be suitably used. The metal substrate may be a substrate in the form of a sheet, foil, coil, wire, rod, etc., or a conventionally known metal formed product such as a construction substrate such as a surface material, a can, a can lid, an exterior material for a battery, etc. The metal substrate may be subjected to a known surface treatment, chemical conversion treatment, plating treatment, etc.

[0035] The metal protective laminate of the present invention can be produced by directly applying the above-mentioned metal protective coating composition to at least one surface of the above-mentioned metal substrate. The coating composition for protecting a metal substrate is preferably applied so that the solids weight of the barrier coating film falls within the above range. In the metal protective coating composition, a barrier coating film can be formed by heating at a temperature of 80 to 220°C, preferably 140 to 220°C, for 1 second to 10 minutes, although this depends on the composition and application amount of the metal oxide, phosphate compound, metal alkoxide, etc. in the composition used.

[0036] The application of the coating composition and the drying or heat treatment can be carried out by a conventionally known method. The application method is not limited to these, but for example, spray coating, immersion, or application with a bar coater, roll coater, gravure coater, or the like is possible. The drying or heating treatment can be carried out by oven drying (heating), infrared heating, high frequency heating, vacuum drying, superheated steam, or the like.

[0037] (Resin-coated metal protection laminate) The metal protective laminate of the present invention can be used alone because the barrier coating film has excellent corrosion resistance, but it can also be used as a resin-coated metal protective laminate in which a resin coating layer is formed on the surface of the barrier coating film. Such a resin coating layer can be a coating film made of a thermosetting resin paint or a film made of a thermoplastic resin, which have been used conventionally as coating layers for metal products. Examples of coating films include coating films made of conventionally known thermosetting resins such as thermosetting acrylic resins, epoxy resins, phenolic resins, and polyester resins. Although it is not possible to define the coating film thickness in general depending on the type of coating material, it is generally 0.1 to 100.0 g / m2 in terms of coating film or solid content weight. 2 , especially 0.5 to 10.0 g / m 2 It is preferable to coat the coating so that the coating amount falls within the range of .

[0038] As the thermoplastic resin film, resin films made of conventionally known thermoplastic resins such as olefin resins, polyester resins, polyamide resins, etc. can be used. In the metal protective laminate of the present invention, it is particularly preferable to use a resin film as the resin coating layer, and particularly preferable to use a resin film made of an olefin resin such as polypropylene, or a polyester resin such as polyethylene terephthalate. The thickness of the resin film is preferably in the range of 1 to 300 μm, particularly 10 to 100 μm, and it is particularly preferable that the resin film is an unstretched film from the viewpoint of molding processability and the like.

[0039] The resin coating layer can be formed from a resin film by extrusion coating of a molten resin directly onto a barrier coating film, or a pre-formed resin film can be laminated onto the metal protection laminate by thermal bonding or using a known adhesive such as a urethane adhesive or an epoxy adhesive. As described above, the barrier coating film of the metal protection laminate of the present invention has excellent adhesion to the resin coating layer or adhesive, and the resin-coated metal protection laminate has excellent interlayer adhesion. [Example]

[0040] The present invention will be further explained by the following examples, but the present invention is not limited to these examples. Various measurement and evaluation methods in the examples and comparative examples are as follows.

[0041] Example 1 [Preparation of gas barrier coating composition] The gas barrier coating composition (hereinafter referred to as "barrier coating") used zirconium oxide sol (Zirconia sol ZSL-00120B (crystalline zirconium oxide, tetragonal system, solid content (ZrO2 equivalent) = 20%) manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.) as the metal oxide. First, the zirconium oxide sol was prepared using water and isopropanol solvent to a solid content of 6.1% and a water / isopropanol ratio of 60 / 40. Next, 44.7 parts by mass of aluminum isopropoxide (manufactured by Wako Pure Chemical Industries, Ltd.) as an additive and 53.5 parts by mass of phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 75%) as a phosphate compound were added per 100 parts by mass of the solid content of the zirconium oxide sol. The mixture was then dispersed using a homogenizer for a predetermined time to obtain a barrier coating.

[0042] [Method for producing metal protective laminate] A metal protection laminate was produced using the prepared barrier coating paint as follows: The above-mentioned barrier coating paint was applied to a substrate of 23 μm thick aluminum foil using a bar coater in an amount of 2.0 g / m2 after drying. 2The coating was then heated and dried in a box oven at 200°C for 2 minutes to obtain a metal protection laminate.

[0043] [Method for preparing a sample for evaluating the corrosion resistance of a metal protective laminate] The metal protection laminate was cut into 5cm squares, leaving only the barrier coated surface exposed, and the edges and backside of the substrate that were not covered were masked with tape. The resulting samples were immersed in a salt-containing citric acid model solution (2% citric acid, 1.65% salt, 0.29% sodium citrate) for corrosiveness evaluation at 40°C, and the corrosiveness was visually evaluated after one week. No corrosion (white rust): 〇 Corrosion (white rust) occurs on the entire surface: ×

[0044] [Method for preparing T-peel strength samples of metal protective laminate] The coating amount was 4.0 g / m on the barrier coat surface of the aforementioned metal protection laminate. 2 A urethane adhesive (Takenate A-315 / Takenate A-50 manufactured by Mitsui Chemicals, Inc.) was applied using a bar coater, dried using a dryer, and then laminated with a 50 μm thick polypropylene film (ZK500 manufactured by Toray Industries, Inc.) to prepare a sample for evaluating T-peel strength.

[0045] [Method for preparing a sample for evaluating the gas barrier properties of a barrier coating film covering a metal protective laminate] The barrier coating paint used in the metal protection laminate described above was used to prepare the laminate as follows: The barrier coating paint was applied to a substrate of 25 μm thick biaxially oriented polyester film (E5102 manufactured by Toyobo Co., Ltd.) using a bar coater in an amount of 2.0 g / m2 after drying. 2 The coating was then heated and dried in a box oven at 200°C for 2 minutes to obtain a gas barrier laminate. The sample for evaluating the gas barrier properties (hereinafter referred to as the "evaluation sample") was prepared by applying a coating amount of 4.0 g / m to the barrier coat surface of the gas barrier laminate. 2The urethane adhesive (Takenate A-315 / Takenate A-50 manufactured by Mitsui Chemicals, Inc.) was applied using a bar coater, dried using a dryer, and then laminated with the 25 μm thick biaxially oriented polyester film to prepare a sample for evaluation of gas barrier properties, etc.

[0046] Example 2 In Example 1, 45 parts by mass of aluminum isopropoxide (manufactured by Wako Pure Chemical Industries, Ltd.) as an additive and 53 parts by mass of phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration=75%) as a phosphate compound were added relative to 100 parts by mass of the solid content of the zirconium oxide sol, and a metal protection laminate, a gas barrier laminate, and an evaluation sample were obtained in the same manner as in Example 1, except that a dispersion treatment was carried out using a disperser for a predetermined period of time.

[0047] Example 3 In Example 1, 29 parts by mass of aluminum glycinate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added as an additive to 100 parts by mass of the solid content of zirconium oxide sol, and 52 parts by mass of phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 75%) was added as a phosphate compound, in terms of the non-volatile content of phosphoric acid, and the barrier coat paint was applied in an amount of 7.5 g / m after drying. 2 The coating was then heated and dried in a box oven at 220° C. for 10 minutes, and a metal protection laminate, a gas barrier laminate, and an evaluation sample were obtained in the same manner as in Example 2.

[0048] Example 4 In Example 3, 29 parts by mass of aluminum isopropoxide (manufactured by Wako Pure Chemical Industries, Ltd.) was added as an additive, and 52 parts by mass of phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., concentration = 75%) was added as a phosphate compound, based on 100 parts by mass of the solid content of the zirconium oxide sol, and the coating amount after drying of the barrier coat paint was 2.0 g / m 2 and then heat-dried in a box oven at 220° C. for 2 minutes. The same method as in Example 3 was used to obtain a metal protection laminate, a gas barrier laminate, and an evaluation sample.

[0049] (Comparative Example 1) The 23-μm thick aluminum foil used in Example 1 was not coated with the barrier coating paint, and a metal protection laminate and a sample for evaluation were obtained in the same manner as in Example 1.

[0050] (Comparative Example 2) A phosphoric acid chromate-treated aluminum plate with a thickness of 280 μm (chromium weight: 20 mg / m 2 ) was not coated with the barrier coating paint, and a metal protection laminate and a sample for evaluation were obtained in the same manner as in Example 1.

[0051] (Evaluation Method) Using the following evaluation methods, as shown in Table 1, the evaluation results of the metal protection laminate, the gas barrier laminate, and the sample for evaluation were obtained.

[0052] [Oxygen Permeability] Each sample for evaluation obtained in the examples and comparative examples was measured using an oxygen permeability measuring device (OX-TRAN2 / 21 manufactured by Modern Control). The measurement conditions were a temperature of 40°C and a relative humidity of 90%.

[0053] [Water Vapor Permeability] Each sample for gas barrier evaluation obtained in the examples and comparative examples was measured using a water vapor permeability measuring device (PERMATRAN-W3 / 34 type manufactured by Modern Control, Deltaperm-UH manufactured by Technolox, and HiBarSens2.0 manufactured by Sempa). The measurement conditions were a temperature of 40°C and a relative humidity of 90%.

[0054] [Infrared Absorption Spectrum] For each metal protection laminate obtained in the examples and comparative examples, the infrared absorption spectrum of the gas barrier coating film applied on the polyester substrate was measured using a Fourier transform infrared spectrophotometer (FT / IR-6600 manufactured by JASCO Corporation). (Measurement Conditions of FT-IR Device) Equipment Used: FT / IR-6600 manufactured by JASCO Measurement conditions: Method: ATR (Ge prism) Attachment: Thunder Dome Wavenumber range: 800-4000cm -1 Film measurement surface Barrier coating surface

[0055] [X-ray fluorescence evaluation] The elements contained in the barrier coat film of each metal protection laminate obtained in the Examples and Comparative Examples were evaluated by quantifying the phosphorus, aluminum, and zirconium elements using a commercially available X-ray fluorescence analyzer. The net strength obtained by measuring each gas barrier laminate was used to calculate the content ratio of each element in the coating film, which was then used for evaluation. <Measurement conditions for X-ray fluorescence analyzer> Equipment used: Rigaku ZSX PrimusIV Measurement conditions: Measurement target P-Kα line, Al-Kα line, Zr-Kα line Measuring diameter 10mm Measurement X-ray Rh (4.0kw) Film measurement surface Measurement is performed by irradiating X-rays from the barrier coating surface side

[0056] [T-peel strength] The peel strength of the evaluation sample was measured using an autograph (Shimadzu Corporation, AG-IS). The peel strength was measured by the T-peel test force when the sample was clamped on both sides of the adhesive-uncoated area with an air chuck, peeled at a width of 15 mm, and tested at a speed of 300 mm / min.

[0057] Tables 1 and 2 show the results of various measurements and evaluations of the above examples and comparative examples.

[0058] [Table 1]

[0059] [Table 2]

[0060] [Abbreviations in Tables 1 and 2] NV: solid content of metal oxide in metal oxide sol; ZSL-00120B: crystalline zirconium oxide; P / Zr: content ratio of phosphorus element (P) derived from phosphate compound to zirconium element (Zr) in metal oxide in gas barrier laminate; Al / Zr: content ratio of aluminum element (Al) derived from additive to zirconium element (Zr) in metal oxide in gas barrier laminate [Industrial Applicability]

[0061] The metal protective laminate of the present invention has excellent corrosion resistance and can therefore be suitably used as an exterior material for a container or a battery that comes into contact with highly corrosive products.

Claims

1. A metal protection laminate comprising a metal substrate and a barrier coating film containing at least a phosphate.

2. 2. The metal protective laminate according to claim 1, wherein the barrier coating film comprises a reaction product obtained by reacting a metal oxide with at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, a metal hydroxide, and an amino acid salt, and a phosphoric acid compound or a sulfuric acid compound.

3. 3. The metal protection laminate according to claim 2, wherein the metal species of the metal oxide, metal alkoxide, and metal hydroxide is at least one of aluminum, titanium, iron, and zirconium.

4. 4. The metal protection laminate according to claim 2, wherein the metal alkoxide is at least one of methoxide, ethoxide, propoxide, isopropoxide, butoxide, isobutoxide, sec-butoxide, and tert-butoxide.

5. 4. The metal protection laminate according to claim 2, wherein the metal alkoxide is aluminum isopropoxide.

6. 4. The gas barrier laminate according to claim 2, wherein the metal hydroxide is aluminum hydroxide.

7. 4. The metal protection laminate according to claim 2, wherein the metal oxide is zirconium oxide or aluminum oxide.

8. 4. The metal protection laminate according to claim 2, wherein the metal oxide is in the form of nanoparticles having a particle diameter of 100 nm or less.

9. 4. The metal protection laminate according to claim 2, wherein the metal oxide is a crystalline zirconium oxide.

10. 4. The metal protection laminate according to claim 2, wherein the amino acid salt is aluminum glycinate.

11. 4. The metal protection laminate according to claim 2, wherein the phosphoric acid compound is at least one of orthophosphoric acid, metaphosphoric acid, polyphosphoric acid, and cyclic polyphosphoric acid.

12. The barrier coating film has an infrared absorption spectrum of 980 to 1100 cm －１ 4. The metal protection laminate according to claim 2, wherein the infrared absorption has a maximum absorption peak in the range of 1000 to 10000.

13. 3. The metal protection laminate according to claim 1, wherein the barrier coating film has a Zr (Zr-kα) to P (P-kα) content ratio (P / Zr) in the range of 0.40 to 2.00 and a Zr (Zr-kα) to P (P-kα) content ratio (Al / Zr) in the range of 0.05 to 0.55, as measured by fluorescent X-ray analysis.

14. 3. The metal protection laminate according to claim 1, wherein the metal substrate is made of any one of aluminum, an aluminum alloy, iron, copper, and titanium.

15. 3. The metal protection laminate according to claim 1, wherein the metal substrate is a metal molded body or a metal foil.

16. 3. A resin-coated metal protection laminate comprising a resin coating layer formed on the barrier coating film of the metal protection laminate according to claim 1 or 2.

17. 1. A coating composition for protecting metal substrates, characterized in that the barrier coating film contains a metal oxide, at least one of a metal alkoxide, a hydrolyzed product of a metal alkoxide, a metal hydroxide, and an amino acid salt, and a phosphoric acid compound or a sulfate compound.

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