Surface treatment agent for aluminum-containing metal material and method for treating aluminum-containing metal material

Abstract

The present invention discloses a surface treatment agent for aluminum-containing metal materials, which is composed of solids and water. The solids include the following components by weight: 0.1% to 18% of a metallic heteropoly acid, 42% to 75% of a high molecular weight polymer having a hydrophilic group, 1% to 15% of a phosphorus compound, and 10% to 35% of a titanium compound. The metallic heteropoly acid is selected from (i) a metallic heteropoly acid containing phosphorus and vanadium ions, (ii) a metallic heteropoly acid containing phosphorus, vanadium ions, and molybdenum ions, (iii) a metallic heteropoly acid containing phosphorus, vanadium ions, and tungsten ions, or (iv) a metallic heteropoly acid containing phosphorus, vanadium ions, molybdenum ions, and tungsten ions. The high molecular weight polymer having a hydrophilic group is selected from polyvinyl alcohol and its derivatives. The mass ratio of the solids to water is 1:3 to 99. The film formed by the surface treatment agent has excellent corrosion resistance and superhydrophilicity.

Description

Technical Field

[0001] The present invention belongs to the field of coatings, and in particular relates to a surface treatment agent for aluminum-containing metal materials, a preparation method thereof, and a method for treating aluminum-containing metal materials. Background Art

[0002] Aluminum and aluminum alloy heat exchangers are widely used in the field of automotive heat exchangers due to their excellent heat exchange capabilities.

[0003] However, when traditional aluminum and aluminum alloy heat exchangers are surface treated, three steps of alkaline washing / pickling, passivation, and hydrophilicity are required to obtain corrosion resistance, hydrophilicity, antibacterial and mildew resistance, etc. The steps are cumbersome and the equipment investment is large. When problems occur, it is difficult to identify the causes.

[0004] For example, the treatment agents used by Japan Parkersei Co., Ltd. for the surface treatment of aluminum and aluminum alloy heat exchangers are as follows:

[0005] Alkaline degreasing agent "FC-3000 series, Japan Parkersei Co., Ltd."

[0006] Zirconium-based chemical treatment agent "CT-3700 series, Japan Parkersei Co., Ltd."

[0007] Hydrophilic treatment agent "LN-5000 series, Japan Parkersei Co., Ltd."

[0008] The product treated in this way has excellent hydrophilicity, corrosion resistance, antibacterial and mildew resistance when used as a three-step agent. However, if degreasing and passivation treatments are not performed, the corrosion resistance and bonding strength cannot meet market demand. Summary of the Invention

[0009] One aspect of the present invention is to provide a surface treatment agent for aluminum-containing metal materials. When the surface of the aluminum-containing metal material is treated with the treatment agent, the surface of the aluminum-containing metal material does not need to be degreased or passivated. Simply applying the treatment agent can form a film on the surface of the aluminum-containing metal material with excellent corrosion resistance, superhydrophilicity, and antibacterial and mildew-proof properties. To achieve this objective, the present invention adopts the following technical solutions:

[0010] A surface treatment agent for aluminum-containing metal materials, consisting of solid matter and water, characterized in that the solid matter includes the following components in weight content:

[0011]

[0012] Wherein, the metal heteropoly acid is selected from one of the following groups:

[0013] (i) a metal heteropoly acid containing a phosphorus atom and a vanadium ion, (ii) a metal heteropoly acid containing a phosphorus atom, a vanadium ion and a molybdenum ion, (iii) a metal heteropoly acid containing a phosphorus atom, a vanadium ion and a tungsten ion, (iv) a metal heteropoly acid containing a phosphorus atom, a vanadium ion, a molybdenum ion and a tungsten ion,

[0014] The high molecular polymer having a hydrophilic group is selected from polyvinyl alcohol and its derivatives,

[0015] The mass ratio of the solid matter to water is 1:3-99.

[0016] In another preferred embodiment of the present invention, the mass ratio of the metallic heteropoly acid to the high molecular polymer having a hydrophilic group is 0.002 to 0.240:1.

[0017] In another preferred embodiment of the present invention, the weight content of the metal heteropoly acid is 1% to 15%.

[0018] In another preferred embodiment of the present invention, the weight content of the high molecular weight polymer having a hydrophilic group is 45-70%.

[0019] In another preferred embodiment of the present invention, the weight content of the phosphorus compound is 1.7% to 12.6%.

[0020] In another preferred embodiment of the present invention, the weight content of the titanium compound is 13% to 30%.

[0021] In another preferred embodiment of the present invention, the chemical formula of the metal heteropoly acid is selected from at least one of the following groups:

[0022] (i)H 3+n PX 12-n V n O 40 , wherein X is Mo or W, n=5~11,

[0023] (ii)H 6+n P2X 18-n V n O 62 , where X is Mo or W, n=8~17,

[0024] (iii)H X PV Y O Z , where X=9~36, Y=5~14, Z=33~42.

[0025] In another preferred embodiment of the present invention, the saponification degree of the polyvinyl alcohol and its derivatives is 90 mol% to 100 mol%.

[0026] In another preferred embodiment of the present invention, the polyvinyl alcohol derivative is obtained by modifying polyvinyl alcohol with ethylene oxide, acrylic acid or maleic acid.

[0027] In another preferred embodiment of the present invention, the structure of the polyvinyl alcohol and its derivatives is selected from at least one of the following groups:

[0028] (i) Wherein R1 is selected from H, an alkyl group containing 1 to 5 carbon atoms, n=5 to 50, and an average molecular weight of 200 to 5000.

[0029] (ii) Wherein R2 is selected from vinylsulfonyl, maleoyl, acryloyl, n=5-50, and average molecular weight=500-8000.

[0030] In another preferred embodiment of the present invention, wherein R1 is selected from H and a straight chain alkyl group containing 1 to 5 carbon atoms.

[0031] In another preferred embodiment of the present invention, the phosphorus compound is selected from phosphorus oxides, inorganic phosphates, organic phosphates, phosphoric acid, phosphoric acid complexes, phosphorus polymers, or combinations thereof.

[0032] In another more preferred embodiment of the present invention, the phosphorus compound is selected from phosphorous acid, aluminum phosphate, sodium dihydrogen phosphate, ammonium dihydrogen phosphate, ammonium metaphosphate, sodium pyrophosphate, methyl phosphine, sodium tripolyphosphate, or a combination thereof.

[0033] In another preferred embodiment of the present invention, the titanium compound is water-soluble and is selected from inorganic acids of titanium, inorganic salts of titanium, organic salts of titanium, titanium-containing complexes, titanium-containing organic compounds, or combinations thereof.

[0034] In another more preferred embodiment of the present invention, the titanium compound is selected from ammonium fluorotitanate, fluorotitanic acid, ethyl titanate, tetraisopropyl titanate, potassium fluorotitanate, sodium fluorotitanate, acetylacetonatotitanium, or a combination thereof.

[0035] In another preferred embodiment of the present invention, the surface treatment agent for aluminum-containing metal materials further includes a pigment, a water-based lubricant, a resin hardener, a water-soluble solvent, a defoaming agent, a colorant, a surfactant, a wetting agent, or a combination thereof.

[0036] Another aspect of the present invention provides a method for preparing the above-mentioned aluminum-containing metal material surface treatment agent, the preparation method comprising the following steps:

[0037] The metallic heteropoly acid, the high molecular polymer having a hydrophilic group, the phosphorus compound, the titanium compound and water are uniformly mixed at room temperature.

[0038] In another aspect, the present invention provides a method for treating an aluminum-containing metal material using the above-mentioned aluminum-containing metal material surface treatment agent, the method comprising the following steps:

[0039] Immerse the aluminum-containing metal material in the aluminum-containing metal surface treatment agent for 10 to 30 seconds, take it out and dry it, and then you can get the aluminum metal material with a hydrophilic film on the surface.

[0040] In another preferred embodiment of the present invention, the dry film thickness of the hydrophilic film is 0.01 g / m 2 ~1.5g / m 2 .

[0041] In another preferred embodiment of the present invention, the drying temperature is 110-180°C.

[0042] In another aspect, the present invention provides an aluminum-containing metal material having excellent corrosion resistance and super hydrophilicity, wherein the surface of the aluminum-containing metal material has a film formed by the above-mentioned aluminum-containing metal material surface treatment agent. DETAILED DESCRIPTION

[0043] In response to the defects of the surface treatment agents for aluminum-containing metal materials in the prior art, the inventors of this application have developed a new type of surface treatment agent for aluminum-containing metal materials after in-depth research. This surface treatment agent does not require alkaline washing / pickling or passivation treatment on the surface of the aluminum-containing metal material. Only the hydrophilic treatment agent is applied to the surface of the aluminum-containing metal material and then dried to form a film with excellent corrosion resistance, super hydrophilicity, and antibacterial and mildew resistance.

[0044] The surface treatment agent for aluminum-containing metal materials of the present invention is composed of solid matter and water, wherein the solid matter includes the following components in weight content:

[0045]

[0046] Wherein, the metal heteropoly acid is selected from one of the following groups:

[0047] (i) a metal heteropoly acid containing phosphorus and vanadium ions, (ii) a metal heteropoly acid containing phosphorus, vanadium ions and molybdenum ions, (iii) a metal heteropoly acid containing phosphorus, vanadium ions and tungsten ions, (iv) a metal heteropoly acid containing phosphorus, vanadium ions, molybdenum ions and tungsten ions,

[0048] The high molecular polymer having a hydrophilic group is selected from polyvinyl alcohol and its derivatives,

[0049] The mass ratio of the solid matter to water is 1:3-99.

[0050] The dosage of each component is as follows:

[0051] The mass of the metal heteropoly acid (A) M) and the mass of the high molecular polymer (B) with a hydrophilic group (B M ), that is, A M :B M =0.002~0.240:1; more preferably 0.011~0.157:1.

[0052] The metal heteropoly acid (A) is the main part of the corrosion inhibitor. When the amount is lower than the above content range, it will lead to insufficient corrosion resistance; when it is higher than the range defined by the present invention, it will promote corrosion. The mass of the high molecular polymer (B) with a hydrophilic group (B M ) accounts for 42 to 75% of the total solid content of the surface treatment agent, and more preferably 45 to 70%. The hydrophilic polymer (B) is used as a hydrophilic substance. When the amount is lower than the above range, the hydrophilicity of the treatment agent formed is insufficient; when it is higher than the above range, the film fixation rate decreases, resulting in the hydrophilicity failing to meet the requirements.

[0053] The mass of phosphorus compound (C) M ) accounts for 1-15% by weight of the total solid content of the surface treatment agent, more preferably 1.7-12.6%. When the amount of the phosphorus compound (C) not containing a metallic heteropoly acid is used as a supplement to the corrosion inhibitor and is below the above range, the corrosion resistance of the film is insufficient; when the amount is above the above range, the substrate is excessively corroded, resulting in the corrosion resistance of the film failing to meet the requirements.

[0054] The mass of titanium compound (D) M ) accounts for 10 to 35% by weight of the total solid content of the surface treatment agent, and more preferably 13 to 30%. The titanium compound (D) serves as a metal bridging agent for the film. When the amount used is lower than the above range, the film fixation rate decreases, resulting in the hydrophilicity and corrosion resistance failing to meet the requirements; when the amount used is higher than the above range, it will lead to excessive cross-linking, and will also promote corrosion of the substrate under acidic conditions, causing the hydrophilicity and corrosion resistance of the film to fail to meet the requirements.

[0055] As can be seen from the above, the agents used in the existing three-step method are usually hydrophilic agents of the adsorption type. A degreasing agent is required to clean the oxide layer on the surface of aluminum and aluminum alloy, as well as a certain brazing agent to ensure that the passivation layer can effectively adhere to the surface of the substrate. Then, a hydrophilic treatment is performed. The hydrophilic agent and the passivation layer form a good bonding force, and the various coatings interact with each other to obtain an excellent corrosion-resistant, super-hydrophilic, antibacterial and anti-mildew film.

[0056] The components C and D contained in the scheme of the present invention are highly reactive and can remove the oxide layer and brazing flux on the surface of aluminum and aluminum alloy (similar to the degreasing effect). At the same time, they form an inorganic passivation layer on the surface of aluminum and aluminum alloy together with A (similar to the passivation process). Component B will also precipitate together. After drying, an organic-inorganic composite film with excellent corrosion resistance, super hydrophilicity, antibacterial and antifungal properties is formed.

[0057] The components of the metal heteropoly acid (A) of the present invention can be controlled by controlling the temperature, pH, molar ratio of each substance, ion exchange, etc. of the system during the synthesis process.

[0058] In one embodiment of the present invention, the chemical formula of the metal heteropoly acid (A) is H 3+n PX 12-n V n O 40 (wherein X is Mo, W, and n is 5 to 11). In another specific embodiment of the present invention, the chemical formula of the metal heteropoly acid (A) is H 6+n P2X 18- n V n O 62 (wherein X is Mo, W, and n is 8 to 17). In another specific embodiment of the present invention, the chemical formula of the metal heteropoly acid (A) is H X PV Y O Z , where X=9~36, Y=5~14, Z=33~42.

[0059] H 3+n PX 12-n V n O 40 Synthesis method

[0060] Dissolve Na2HPO4·2H2O and Na2XO4·2H2O in water, heat and stir until completely dissolved (system temperature is controlled at 50-60°C), use sulfuric acid for acidification, adjust the system pH to 1-4, monitor the pH during the process, until the solution turns yellow, slowly add NaVO3 to the reaction system (system temperature is controlled at 50-60°C) until the solution color turns orange-yellow, continue to add sulfuric acid for acidification, adjust the system pH to 1-4, after NaVO3 is completely dissolved, cool to room temperature, transfer to a separatory funnel, extract with ether, separate the extract after extraction, transfer to pure water, use an oscillator to fully oscillate, let stand and separate, use nitrogen bubbling to blow out the ether. You can get the molecular formula H 3+ n PX 12-n V n O 40Metal heteropoly acid, wherein n: 5 to 11.

[0061] H 6+n P2X 18-n V n O 62 Synthesis method

[0062] Dissolve Na2HPO4·2H2O and Na2XO4·2H2O in water, stir until completely dissolved, use sulfuric acid for acidification, heat to 70-80℃, adjust the pH of the system to 1-4, wait for the solution to turn yellow, slowly add NaVO3 (temperature controlled at 70-80℃), the solution color turns orange-yellow, continue to add sulfuric acid for acidification, adjust the pH of the system to 1-4, wait for NaVO3 to completely dissolve, reflux for about 2 hours, stop heating, cool to room temperature, transfer to a separatory funnel, extract with ether, separate the extract after extraction, transfer to pure water, use an oscillator to fully oscillate, let it stand and separate, use nitrogen bubbling to blow out the ether. You can get the molecular formula H 6+n P2X 18-n V n O 62 The metal heteropoly acid (A), wherein n: 8 to 17.

[0063] The metallic heteropoly acid (A) of the present invention can be used alone or in combination with the above-mentioned production method.

[0064] In the high molecular weight polymer (B) described herein, a hydrophilic group refers to a chemical group that readily forms hydrogen bonds with water, such as a hydroxyl group, an ether group, or a sulfonic acid group. Such high molecular weight polymers include, but are not limited to, polyvinyl alcohol and polyvinyl alcohol derivatives, having a saponification degree of 90 mol% or greater. Polyvinyl alcohol derivatives can be modified with ethylene oxide, acrylic acid, maleic acid, or the like, but the modification method is not limited thereto.

[0065] In a specific embodiment of the present invention, the structure of polyvinyl alcohol or polyvinyl alcohol derivative is as follows:

[0066]

[0067] Wherein R1 is selected from H, an alkyl group containing 1 to 5 carbon atoms, n=5 to 50, and an average molecular weight of 200 to 5000.

[0068] n:5~50,

[0069] Average molecular weight: 200~5000,

[0070] Saponification degree: 90 mol% or more.

[0071] In a specific embodiment of the present invention, the structure of polyvinyl alcohol or polyvinyl alcohol derivative is as follows:

[0072]

[0073] R2: can be vinylsulfonyl, maleyl, acryloyl, etc.

[0074] n: 5~50,

[0075] Average molecular weight: 500~8000.

[0076] The phosphorus compound (C) described herein as part of the corrosion inhibitor is not particularly limited, and any compound containing phosphorus atoms can be used in the present invention, except that it does not contain a phosphorus metal heteropolyacid. However, it is preferably water-soluble. Examples of the phosphorus compound (C) used in the present invention include phosphorus oxides, phosphates, organophosphates, phosphoric acid, phosphorus-containing complexes, phosphorus-containing polymers, and the like. More specifically, examples include phosphorous acid, aluminum phosphate, sodium dihydrogen phosphate, ammonium dihydrogen phosphate, ammonium metaphosphate, sodium pyrophosphate, methyl phosphonium, and sodium tripolyphosphate.

[0077] The titanium compound (D) described in the present invention is any compound containing a titanium atom and can be used in the present invention without particular limitation, but is preferably water-soluble. Examples of the titanium compound (D) used in the present invention include, but are not limited to, inorganic acids of titanium, inorganic salts of titanium, organic salts of titanium, titanium-containing complexes, and titanium-containing organic compounds. More specifically, examples include, but are not limited to, ammonium fluorotitanate, fluorotitanic acid, ethyl titanate, tetraisopropyl titanate, potassium fluorotitanate, sodium fluorotitanate, and acetylacetonato titanium oxide. One or more titanium compounds (D) can be used.

[0078] In addition to the above-mentioned components, the surface treatment agent for aluminum-containing metal materials of the present invention can be compounded with a bactericide as needed to provide antibacterial and mildew-proof properties, and can also be compounded with other components such as pigments, water-based lubricants, resin hardening components, water-soluble solvents, defoaming agents, colorants, surfactants, and wettability improvers that are beneficial for uniform coating.

[0079] The solid content concentration of the aluminum-containing metal material surface treatment agent of the present invention is not particularly limited as long as the effects of the present invention can be achieved, but is preferably 1.0 to 20% by mass.

[0080] The preparation method of the aluminum-containing plate surface treatment agent of the present invention is not particularly limited. For example, the preparation method can be prepared by sequentially compounding (adding) a metallic heteropoly acid (A), a high molecular weight polymer having a hydrophilic group (B), a phosphorus compound (C), and a titanium compound (D) in a liquid medium such as water, and further adding other ingredients as needed. The order of adding the above components can be appropriately changed as needed, or several components can be premixed before adding to the liquid medium such as water. In addition, if necessary, heating or mixing followed by heating before adding other components can be performed, or multiple components can be premixed in different stages.

[0081] By coating the surface of an aluminum-containing material with the surface treatment agent and drying it, aluminum or an aluminum heat exchanger having a film on the surface can be manufactured.

[0082] The term "aluminum-containing metal material" as used herein refers to materials made of aluminum or aluminum alloys, such as aluminum plates, aluminum heat exchangers, shaped objects such as sheet metal structures (e.g., aluminum foil), and other products made of aluminum alloys, including 3A21 (LF21), Japanese A3003 (JIS), European EN AW3003 (EN), and 3102.

[0083] The surface treatment agent for aluminum-containing metal materials disclosed herein is a novel surface treatment agent. Unlike commercially available surface treatment agents, the surface treatment agent can be applied directly to aluminum-containing metal materials (e.g., aluminum plates and aluminum heat exchangers) without requiring pre-cleaning with degreasing agents, alkaline cleaning, hot water washing, acid washing, or solvent washing. If pre-cleaning is required, hot water or weakly alkaline water is preferred.

[0084] The hydrophilic surface treatment agents used in the prior art have insufficient corrosion resistance, and the film-forming method is mainly adsorption-type. When degreasing and cleaning are not performed, the surface environment of the aluminum-containing metal material is not conducive to the adhesion of the film. Without passivation treatment, the corrosion resistance is poor and cannot meet market demand. The aluminum-containing metal material treatment agent of the present invention is a reactive treatment agent with good film bonding strength. It also contains a metallic heteropoly acid. Only by applying the treatment agent can a film with the same corrosion resistance as the film obtained by the three-step treatment in the prior art be obtained. In other words, the aluminum-containing metal material surface treatment agent of the present invention does not require tedious steps such as degreasing, passivation and water washing on the surface of the aluminum-containing metal material when used. Direct coating can obtain a surface coating with excellent corrosion resistance and super hydrophilicity.

[0085] The surface treatment agent for aluminum-containing metal materials of the present invention can be applied to a portion or all of the surface of the aluminum-containing metal material. The method of using the surface treatment agent for aluminum-containing metal materials of the present invention is not particularly limited. For example, taking aluminum foil as an example, the aluminum foil can be coated with the surface treatment agent of the present invention by roller coating before processing and forming, can be coated with the surface treatment agent of the present invention by dipping after processing and forming, can be coated with the surface treatment agent of the present invention by spraying after processing and forming, and can be coated with the surface treatment agent of the present invention by rod coating before processing and forming. During coating, the temperature of the surface treatment agent for aluminum-containing plate material of the present invention is not particularly limited and can be 5°C to 40°C, more preferably 10°C to 25°C.

[0086] The drying method for the aluminum-containing metal material coated with the surface treatment agent of the present invention is not particularly limited. In addition to drying in a gas oven, other methods include drying in an electric oven, a hair dryer, a hot air oven, a high-frequency induction oven, and an infrared oven. The drying temperature is not particularly limited, but is preferably between 110°C and 180°C.

[0087] The adhesion amount of the dry film formed by the surface treatment agent of the present invention is not particularly limited, but is preferably 0.01 to 1.5 g / m 2 , more preferably 0.1 to 1.0 g / m 2 .

[0088] In the description of the present invention, "normal temperature" refers to 0-40°C, more preferably, 25°C±5°C.

[0089] Compared with the prior art, the advantages of the present invention are:

[0090] 1. When the aluminum-containing metal material surface treatment agent of the present invention is used to treat the aluminum-containing metal material, there is no need to degrease or passivate the surface of the aluminum metal material.

[0091] 2. The film formed by the surface treatment agent for aluminum-containing metal materials of the present invention has excellent corrosion resistance, super hydrophilicity, antibacterial and mildew-proof properties, etc.

[0092] The present invention will be further described below with reference to specific examples. It should be understood that the following examples are intended only to provide best practices of the present invention and should not be construed as limiting the scope of the present invention. Experimental methods in the following examples, where specific conditions are not specified, generally followed conventional operating methods and conditions, or the conditions recommended by the manufacturer. Unless otherwise indicated, percentages and parts are calculated by weight.

[0093] In the following examples, the ingredients used to prepare the surface treatment agent are as follows:

[0094] Metallic heteropoly acid A1:H 12 PW3V9O 40

[0095] The synthesis method of metal heteropoly acid A1 is as follows:

[0096] 0.015 mol of Na2HPO4·2H2O and 0.045 mol of Na2WO4·2H2O were dissolved in 80 ml of pure water, heated and stirred until completely dissolved (the system temperature was controlled at 50-60°C), acidified with sulfuric acid, and the pH of the system was adjusted to 1-4. During this period, the pH of the system was monitored. When the solution turned yellow, 0.135 mol of NaVO3 was slowly added to the system (the system temperature was controlled at 50-60°C). When the solution color turned orange-yellow, sulfuric acid was further added for acidification, and the pH of the system was adjusted to 1-4. After complete dissolution, the solution was cooled to room temperature and transferred to a separatory funnel. Ether was used for extraction. After extraction, the extract was separated and transferred to 80 ml of pure water. The extract was fully shaken using an oscillator. After standing, the layers were separated and the ether was blown out using nitrogen bubbling. A metal heteropoly acid solution (A1 solution) with a mass concentration of 31.7% was obtained.

[0097] Metallic heteropoly acid A2:H 21 P2Mo3V 15 O 62

[0098] The synthesis method of metal heteropoly acid A2 is as follows:

[0099] Dissolve 0.02 mol of Na2HPO4·2H2O and 0.03 mol of Na2MoO4·2H2O in 80 ml of pure water and stir until completely dissolved. Acidify with sulfuric acid, heat the system to 70-80°C, and adjust the pH of the system to 1-4. When the solution turns yellow, slowly add 0.15 mol of NaVO3 to the system (the system temperature is controlled at 70-80°C). When the solution color turns orange-yellow, continue to add sulfuric acid for acidification and adjust the pH of the system to 1-4. After complete dissolution, reflux for 2 hours, stop heating, cool to room temperature, transfer to a separatory funnel, and extract with 100 ml of diethyl ether. After extraction, separate the extract, transfer to 80 ml of pure water, shake thoroughly with an oscillator, let it stand, separate the layers, and blow out the diethyl ether using nitrogen bubbling. This will give a metallic heteropoly acid solution (A2 solution) with a mass concentration of 26.6%.

[0100] Metallic heteropoly acid A3:H 22 P2W2V 16 O 62

[0101] The synthesis method of metal heteropoly acid A3 is as follows:

[0102] 0.02 mol of Na2HPO4·2H2O and 0.02 mol of Na2WO4·2H2O were dissolved in 80 ml of pure water and stirred until completely dissolved. The mixture was acidified with sulfuric acid and the system was heated to 70-80°C. The pH of the system was adjusted to 1-4. When the solution turned yellow, 0.16 mol of NaVO3 was slowly added to the system (the system temperature was controlled at 70-80°C). When the solution color turned orange-yellow, sulfuric acid was further added for acidification. The pH of the system was adjusted to 1-4. After complete dissolution, the mixture was refluxed for 2 hours, the heating was stopped, the mixture was cooled to room temperature, and the mixture was transferred to a separatory funnel. The mixture was extracted with 100 ml of ether. After extraction, the extract was separated and transferred to 80 ml of pure water. The mixture was fully shaken with an oscillator. After standing, the mixture was separated and the ether was blown out with nitrogen bubbling. A metallic heteropoly acid solution (A3 solution) with a mass concentration of 28.2% was obtained.

[0103] B1: Polyvinyl alcohol [PVA-1117K]

[0104] B2: Modified polyvinyl alcohol

[0105] C1: diammonium phosphate

[0106] C2: Sodium tripolyphosphate

[0107] D1: Fluotitanic acid

[0108] D2: Titanium acetylacetonate

[0109] According to the usage ratio of the solid content listed in Table 1, the above components were uniformly mixed with water at room temperature to prepare a surface treatment agent for aluminum-containing metal materials, thereby obtaining the surface treatment agents for aluminum-containing metal materials of Examples 1 to 15 and Comparative Examples 1 to 16. In these surface treatment agents, except for components (A) to (D) listed in Table 1, the remainder is deionized water, and the mass content of the solid content is 10.0%.

[0110] Table 1 Components and contents of solid content of surface treatment agent for aluminum-containing metal materials.

[0111]

[0112] The aluminum-containing metal material surface treatment agents of Examples 1 to 15 and Comparative Examples 1 to 16 are coated on the surface of an aluminum heat exchanger to form a film. The aluminum heat exchanger is made of aluminum alloy 3102 and has a fin thickness of 0.7 mm.

[0113] Comparative Example 17 is a sample produced using a three-step process using existing technology: degreasing treatment uses the degreasing agent FC-3000 series (45°C, 1% concentration) of Japan Parkersei Co., Ltd., passivation treatment uses the passivating agent CT-3700 series (60°C, 5% concentration) of Japan Parkersei Co., Ltd., and hydrophilic treatment uses the hydrophilic agent LN-5000 series (25°C, 50% concentration) of Japan Parkersei Co., Ltd.

[0114] Comparative Example 18 changes the existing three-step treatment to a one-step treatment (without degreasing and passivation treatment steps): the hydrophilic treatment uses the LN-5000 series (50% concentration at 25°C) of Japan Parkersei Co., Ltd. to produce the sample.

[0115] The production process of aluminum heat exchanger with membrane is as follows:

[0116] The aluminum heat exchanger was immersed in the aluminum-containing metal material surface treatment agent of Examples 1 to 15 and Comparative Examples 1 to 16 to form a 1.0 g / m 2 The film adhesion amount (dry film) was measured, and a circulating hot air oven was used for drying at a core surface temperature of 160°C to obtain samples 1 to 31.

[0117] Performance evaluation test of aluminum heat exchanger with membrane:

[0118] The following performance evaluation test was conducted on samples 1 to 31. The evaluation results are shown in Table 2. Regarding the evaluation criteria, "△", "○", and "◎" mean that the performance is satisfactory for practical use.

[0119] 1) Initial hydrophilicity:

[0120] The treated samples were tested using a contact angle meter and their initial hydrophilicity was evaluated according to the following criteria (θ represents hydrophilicity).

[0121] <Evaluation Criteria>

[0122] ◎:Θ≤10°

[0123] ○: 10°<Θ≤15°

[0124] △: 15°<Θ≤20°

[0125] ×: Θ>20°

[0126] 2) Hydrophilicity after deterioration 1:

[0127] The treated samples were subjected to a 72-hour pure water flow test at a controlled flow rate of 2 L / min. After the flow was completed, the samples were dried in an 80°C oven for 1 hour. The treated samples were tested using a contact angle meter and their hydrophilicity was evaluated according to the following standards.

[0128] ◎:Θ≤20°

[0129] ○:20°<Θ≤25°

[0130] △: 25°<Θ≤30°

[0131] ×: Θ>30°

[0132] 3) Hydrophilicity after deterioration 2:

[0133] The treated samples were subjected to a 168-hour pure water flow test at a controlled flow rate of 2 L / min. After the flow was completed, the samples were dried in an 80°C oven for 1 hour. The treated samples were tested using a contact angle meter and their hydrophilicity was evaluated according to the following standards.

[0134] ◎:Θ≤20°

[0135] ○:20°<Θ≤25°

[0136] △: 25°<Θ≤30°

[0137] ×: Θ>30°

[0138] 4) Corrosion resistance 1:

[0139] The aluminum alloy evaporator with the coating was placed in a neutral salt spray chamber (35°C, 5% sodium chloride) for 240 hours, rinsed three times with water, and dried in an 80°C oven for 1 hour. The percentage of white rust on the fins of the aluminum alloy evaporator was evaluated and recorded as S.

[0140] <Evaluation Criteria>

[0141] ◎:S≤5%

[0142] ○: 5%<S≤10%

[0143] △: 10%<S≤20%

[0144] ×: S>20%

[0145] 5) Corrosion resistance 2:

[0146] The aluminum alloy evaporator with the coating was placed in a neutral salt spray chamber (35°C, 5% sodium chloride) for 480 hours, rinsed three times with water, and dried in an 80°C oven for 1 hour. The percentage of white rust on the fins of the aluminum alloy evaporator was evaluated and recorded as S.

[0147] <Evaluation Criteria>

[0148] ◎:S≤5%

[0149] ○: 5%<S≤10%

[0150] △: 10%<S≤20%

[0151] ×: S>20%

[0152] 6) Binding strength:

[0153] The bonding strength was tested using a grid knife and rated as follows.

[0154] ◎:100 / 100

[0155] ○: 95 / 100~99 / 100

[0156] △: 90 / 100~94 / 100

[0157] ×:<90 / 100

[0158] The evaluation results are shown in Table 2 below.

[0159] Table 2

[0160]

[0161]

[0162] Comparative Examples 1-3 and Examples 1-4 compare the performance of different addition amounts of Component A in the treatment agent. When Component A in the treatment agent is within the range specified by this invention, but outside the optimal range, the resulting film exhibits good corrosion resistance; when within the optimal range, the resulting film exhibits excellent corrosion resistance. In Comparative Examples 1-3, where Component A is not within the range specified by this invention and the addition amount is insufficient, the resulting film exhibits poor corrosion resistance. When the addition amount exceeds this range, excessive corrosion results, also resulting in poor corrosion resistance.

[0163] Comparative Example 4 and Examples 5-8 compare the performance of different addition amounts of Component B. When Component B in the treatment agent is within the range specified by this invention, but outside the optimal range, the resulting film has good hydrophilicity; when it is within the optimal range, the resulting film has excellent hydrophilicity. In Comparative Example 4, where Component B is outside the range specified by this invention and the addition amount is insufficient, the resulting film has poor hydrophilicity. When the addition amount exceeds this range, the resulting film has slightly better hydrophilicity, but the addition amounts of other components in the treatment agent are limited, resulting in poorer other properties of the resulting film.

[0164] Comparative Examples 9-12 and Examples 9-11 compare the performance of the treatment agent at different addition levels of Component D. When Component D is within the range specified by the present invention but outside the optimal range, the resulting films exhibit good adhesion. When Component D is within the optimal range, the resulting films exhibit excellent adhesion. In Comparative Examples 9-12, where Component D is outside the range specified by the present invention and the addition level is insufficient, the resulting films exhibit poor adhesion. When the addition level exceeds the optimal range, the resulting films exhibit poor adhesion due to excessive erosion.

[0165] Comparative Examples 5-8 and Examples 12-15 compare the performance of the treatment agent at different addition levels of Component C. When Component C is within the range specified by this invention, but outside the optimal range, the resulting films exhibit good corrosion resistance. When Component C is within the optimal range, the resulting films exhibit excellent corrosion resistance. In Comparative Examples 5-8, where Component C is outside the range specified by this invention and the addition level is insufficient, the resulting films exhibit poor corrosion resistance. When the addition level exceeds this range, the corrosion resistance of the resulting films deteriorates due to excessive corrosion.

[0166] When the components of the treatment agents in Comparative Examples 13 to 16 are not within the range defined by the present invention, the films obtained by the treatment agents do not meet the requirements of corrosion resistance, adhesion, and hydrophilicity.

[0167] Comparative Example 17 is a product obtained using the three-step method of the prior art. When processed using the three-step method, the obtained film has good corrosion resistance and excellent hydrophilicity.

[0168] Comparative Example 18 is a product obtained by the three-step method using existing technology. It is a product obtained by the one-step method without performing degreasing and passivation processes. When processed by the one-step method, the obtained film has good hydrophilicity, but insufficient corrosion resistance and unsatisfactory bonding strength.

[0169] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Various modifications are possible. In other words, any simple, equivalent changes and modifications made in accordance with the claims and description of the present invention are within the scope of protection of the patent claims. Anything not fully described in this invention constitutes conventional technology.

Claims

1. A surface treatment agent for aluminum-containing metal materials, consisting of solid matter and water, characterized in that: The solid content includes the following components by weight: Wherein, the metal heteropoly acid is selected from one of the following groups: (i) a metal heteropoly acid containing phosphorus and vanadium ions, (ii) a metal heteropoly acid containing phosphorus, vanadium ions and molybdenum ions, (iii) a metal heteropoly acid containing phosphorus, vanadium ions and tungsten ions, (iv) a metal heteropoly acid containing phosphorus, vanadium ions, molybdenum ions and tungsten ions; The phosphorus compound does not contain a metallic heteropoly acid, The high molecular polymer having a hydrophilic group is selected from polyvinyl alcohol and its derivatives, The mass ratio of the solid matter to water is 1:3 to 99, The mass ratio of the metallic heteropoly acid to the high molecular polymer having a hydrophilic group is 0..002-0.240:

1.

2. The surface treatment agent for aluminum-containing metal materials according to claim 1, characterized in that: The chemical formula of the metal heteropoly acid is at least one selected from the following groups: (i)H 3+n PX 12-n V n O 40 , wherein X is Mo or W, n=5~11, (ii)H 6+n P2X 18-n V n O 62 , where X is Mo or W, n=8~17, (iii)H X PV Y O Z , where X=9~36, Y=5~14, Z=33~42.

3. The surface treatment agent for aluminum-containing metal materials according to claim 1, characterized in that: The saponification degree of the polyvinyl alcohol and its derivatives is 90 mol% to 100 mol%, The polyvinyl alcohol derivative is obtained by modifying polyvinyl alcohol with ethylene oxide, acrylic acid or maleic acid.

4. The surface treatment agent for aluminum-containing metal materials according to claim 1, characterized in that: The structure of the polyvinyl alcohol and its derivatives is selected from at least one of the following groups: (i) Wherein R1 is selected from H, an alkyl group containing 1 to 5 carbon atoms, n=5 to 50, and an average molecular weight of 200 to 5000. (ii) Wherein R2 is selected from vinylsulfonyl, maleoyl, acryloyl, n=5-50, and average molecular weight=500-8000.

5. The surface treatment agent for aluminum-containing metal materials according to claim 1, characterized in that: The phosphorus compound is selected from phosphorus oxides, inorganic phosphates, organic phosphates, phosphoric acid, phosphoric acid complexes, phosphorus polymers, or combinations thereof.

6. The surface treatment agent for aluminum-containing metal materials according to claim 1, characterized in that: The titanium compound is water-soluble and is selected from inorganic acids of titanium, inorganic salts of titanium, complexes containing titanium, organic compounds containing titanium, or combinations thereof.

7. The surface treatment agent for aluminum-containing metal materials according to claim 1, characterized in that: The surface treatment agent for aluminum-containing metal materials further includes a pigment, a water-based lubricant, a resin hardener, a water-soluble solvent, a defoaming agent, a surfactant, a wetting agent, or a combination thereof.

8. The method for preparing the surface treatment agent for aluminum-containing metal materials according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: The metallic heteropoly acid, the high molecular polymer having a hydrophilic group, the phosphorus compound, the titanium compound and water are uniformly mixed at room temperature.

9. A method for treating an aluminum-containing metal material using the aluminum-containing metal material surface treatment agent according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: Immerse the aluminum-containing metal material in the aluminum-containing metal surface treatment agent for 10 to 30 seconds, take it out and dry it, and then you can get an aluminum metal material with a hydrophilic film on the surface. The dry film of the hydrophilic film is 0.01g / m 2 ~1.5g / m 2 .

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