Cleaning fluid as well as preparation method and application thereof

Abstract

The invention discloses a cleaning solution as well as a preparation method and application thereof, and relates to the field of metal surface treatment. The cleaning solution provided by the invention is weakly acidic and comprises the ash removing agent, the organic acid, the passivator, the builder and the water, the ash removing agent comprises the main components of a fluorine-containing compound, a liquid alcohol compound and a liquid phosphoric acid compound, and the fluorine-containing compound can effectively remove hanging ash formed by a silicon structure separated out from the surface of an aluminum part; and other components can effectively remove oil stains and dust on the surface of the part. Experimental results show that the cleaning solution provided by the invention can effectively remove dust, oil stains and dust on the surface of the aluminum part, and does not influence the electroplated part of the part; and in addition, the binding force between the non-electroplated part of the part and the pouring layer can be improved, and the binding strength reaches up to 22.5 MPa.

Description

Technical Field

[0001] The invention relates to the field of metal surface treatment, and in particular to a cleaning liquid, a preparation method and application thereof. Background Art

[0002] Aluminum and its alloys have good electrical conductivity and are often used as materials for conductive parts in the electrical appliance manufacturing industry. However, the surface of aluminum and its alloys is easily oxidized to form an oxide film, which will reduce the conductivity of aluminum parts and increase resistance. Therefore, in actual operation, the electrical contact parts of aluminum parts are partially electroplated, and the non-electroplated parts are protected with resist paint or insulating glue. After the electroplating is completed, they are removed, polished, and cast with an insulating layer.

[0003] However, after the plating resist or insulating adhesive on the non-electroplating part is stripped off, a lot of oil will remain, and metal dust will remain on the surface of the part after polishing. The silicon structure contained in the aluminum alloy is easy to precipitate, forming black silicon ash with strong bonding force on the surface of the part, which will affect the bonding force between the subsequent casting insulation layer and the non-electroplating part, and will also affect the performance and stability of the overall equipment. Therefore, after removing the plating resist or insulating adhesive on the surface of the non-electroplating part, effective cleaning measures must be taken.

[0004] Currently, the main methods for removing oil, dust and ash from the surface of aluminum parts are ultrasonic cleaning and manual wiping. Ultrasonic cleaning can effectively clean oil and dust on the surface of parts, but it cannot effectively remove ash with very strong bonding force. In addition, there is energy attenuation in the conduction of ultrasonic waves, and the cleaning effect is not good for parts with internal cavity structures. Manual wiping is difficult to effectively clean parts with complex structures, and oil, dust and ash will still remain on the surface of the parts after wiping. Summary of the invention

[0005] In view of this, the present invention provides a cleaning liquid, a preparation method and an application thereof. The cleaning liquid provided by the present invention can effectively remove oil stains, dust and ash on aluminum parts after local electroplating, has no effect on the local electroplated parts, and can enhance the bonding strength between the parts and the subsequent casting layer.

[0006] The present application provides a cleaning liquid comprising the following components in mass fractions: 5% to 20% of a deashing agent, 3% to 15% of an organic acid, 1% to 10% of a passivating agent, 0.5% to 10% of a builder, and 66% to 89.5% of water, the sum of the mass fractions of the components being 100%;

[0007] Wherein, the deashing agent includes liquid phosphoric acid compounds, liquid alcohol compounds and fluorine-containing compounds;

[0008] The fluorine-containing compound includes at least one of a liquid fluorine-containing compound and a fluorine-containing compound solution.

[0009] The present application cleans aluminum parts after local electroplating by introducing liquid phosphoric acid compounds, liquid alcohol compounds and fluorine-containing compounds into the dust removal agent, wherein the fluoride in the fluorine-containing compound can react with the dust on the surface of the aluminum parts to effectively remove it; the other components can remove oil stains and metal dust on the surface of the aluminum alloy, and form a protective film on the surface to improve the brightness of the surface of the parts.

[0010] In the present application, the fluorine-containing compound can be a liquid fluorine-containing compound, a fluorine-containing compound solution, or a mixed solution of the two, and the present invention has no particular restrictions on this. In some specific implementations, the liquid fluorine-containing compound is fluoroboric acid. In some specific implementations, the fluorine-containing compound solution is at least one of hydrofluoric acid, ammonium fluoride solution, ammonium bifluoride solution and sodium fluorosilicate solution.

[0011] Liquid alcohol compounds have good degreasing properties and can quickly penetrate into the tiny gaps on the surface of metal parts to remove the hard-to-remove dirt and grease, making the metal surface clean again; at the same time, alcohol cleaning agents also have low surface tension and can well infiltrate the metal surface, ensuring a more uniform and thorough cleaning effect. In some specific implementations, the liquid alcohol compound described in the present application is selected from at least one of ethanol, ethylene glycol, glycerol and benzyl alcohol.

[0012] Liquid phosphoric acid compounds have moderate acidity, relatively low corrosion to the surface of metal parts, less damage to materials, and can react with oxides or rust on the metal surface to generate phosphates that are insoluble in water, thereby removing them from the metal surface. In some specific implementations, the liquid phosphoric acid compound described in the present application is selected from at least one of polyphosphoric acid, phosphoric acid and pyrophosphoric acid.

[0013] In the present application, the volume ratio of liquid phosphoric acid compounds, liquid alcohol compounds and fluorine-containing compounds in the deashing agent is (1-5):(1-7):(1-6), preferably (1-4):(2-6):(2-6), and more preferably (1-3):(2-5):(3-5).

[0014] The organic acid, passivator and builder in the cleaning solution provided in the present application can work synergistically with the dust remover when cleaning the surface of aluminum parts, effectively removing metal dust, dust and oil stains on the surface of the parts, and forming a dense oxide film on the surface of the parts.

[0015] The organic acid can effectively remove grease, dirt and other impurities on the surface of metal parts, making the metal surface clean. In some specific implementations, the organic acid is selected from one or more of tartaric acid, phytic acid, glacial acetic acid, monohydrated citric acid, lactic acid, succinic acid, ascorbic acid and oxalic acid.

[0016] The passivating agent can form a dense protective film on the metal surface, enhancing the bonding force between the non-electroplated part of the part and the subsequent cast insulating layer. The passivating agent is selected from one or more of sodium persulfate, potassium permanganate, potassium chlorate, sodium hypochlorite, potassium nitrate, potassium dichromate, hydrogen peroxide, chromic anhydride, and chromium sulfate.

[0017] The builder can soften the water quality, avoid the scaling problem caused by the deposition of hard water ions on the metal surface, and reduce the surface tension of water, improve the permeability and wettability of the cleaning liquid, and thus enhance the cleaning effect. In some specific implementations, the builder is selected from one or more of methanesulfonic acid, ethylsulfonic acid, potassium thiocyanate, sodium bisulfate, aminosulfonic acid and urea.

[0018] The present application also provides a method for preparing a cleaning solution, comprising:

[0019] The deashing agent, organic acid, passivating agent, builder and water are uniformly mixed to obtain a cleaning solution;

[0020] Wherein, the deashing agent includes liquid phosphoric acid compounds, liquid alcohol compounds and fluorine-containing compounds;

[0021] The fluorine-containing compound includes at least one of a liquid fluorine-containing compound and a fluorine-containing compound solution.

[0022] In the present application, a dust remover, an organic acid, a passivator, a builder and water are mixed together as a cleaning liquid for aluminum parts after electroplating. The dust remover can effectively remove dust after electroplating. The organic acid, the passivator and the builder work together with the dust remover to make the surface of the cleaned parts bright and free of dust and metal dust.

[0023] The present application firstly mixes the liquid alcohol compound and the liquid phosphoric acid compound evenly, heats and keeps the mixture warm, and then adds the fluorine-containing compound to obtain the deashing agent. In some specific implementations, the liquid alcohol compound and the liquid phosphoric acid compound can be evenly mixed, then heated to 60 to 110° C., preferably 65 to 110° C., and more preferably 70 to 110° C.; and kept warm for 20 to 60 minutes, preferably 25 to 60 minutes, and more preferably 25 to 55 minutes.

[0024] The cleaning liquid provided in the present application can effectively remove dust, dirt and oil stains on the surface of parts, and at the same time form a dense protective film. Therefore, the present application uses it to clean aluminum parts after partial electroplating. The application range includes but is not limited to partial silver plating, partial tin plating, partial copper plating, partial nickel plating, partial gold plating, etc.

[0025] On this basis, the cleaning solution provided in this application can be preheated to 20-50°C when used, and then the partially electroplated aluminum parts with the insulation layer removed can be immersed in it for 1-3 minutes. After the immersion, the parts can be taken out, washed with water, and dried. The method of using the cleaning solution provided in this application is not limited to the above method, and those skilled in the art can decide for themselves according to actual conditions.

[0026] The present application provides a cleaning liquid including a dust remover, an organic acid, a passivating agent, a builder and water, wherein the main components of the dust remover are fluorine-containing compounds, liquid alcohol compounds and liquid phosphoric acid compounds. The fluoride in the fluorine-containing compounds can react with the dust on the surface of aluminum parts to effectively remove it; the liquid alcohol compound can remove dust that is difficult to remove and restore the metal surface to cleanliness; the liquid phosphoric acid compound can react with oxides or rust on the metal surface to remove them from the metal surface. While ensuring the cleaning power, the cleaning liquid provided in the present application can also form a dense oxide film on the surface of the aluminum parts, thereby improving the bonding strength between the parts and the subsequent casting layer and increasing their service life. DETAILED DESCRIPTION

[0027] It should be understood that the expression "one or more of..." includes each of the items recited after the expression individually and in various different combinations of two or more of the recited items, unless otherwise understood from the context and usage. The expression "and / or" in combination with three or more recited items should be understood to have the same meaning, unless otherwise understood from the context.

[0028] The use of the terms "comprising", "having" or "containing", including their grammatical synonyms, should generally be understood as open and non-restrictive, for example not excluding other unrecited elements or steps, unless otherwise specifically stated or otherwise understood from the context.

[0029] It should be understood that the order of steps or the order in which certain actions are performed is not important as long as the present invention remains operable. In addition, two or more steps or actions may be performed simultaneously.

[0030] The use of any and all examples or exemplary language, such as "for example" or "including", herein is intended only to better illustrate the invention and does not limit the scope of the invention unless otherwise claimed. No language in this specification should be construed as indicating that any non-claimed element is essential to the practice of the invention.

[0031] In addition, the numerical ranges and parameters used to define the present invention are approximate values, and the relevant values ​​in the specific embodiments have been presented as accurately as possible. However, any numerical value inherently inevitably contains standard deviations due to individual test methods. Therefore, unless otherwise expressly stated, it should be understood that all ranges, quantities, values ​​and percentages used in this disclosure are modified by "about". Here, "about" generally means that the actual value is within plus or minus 10%, 5%, 1% or 0.5% of a specific value or range.

[0032] The present application provides a cleaning liquid comprising the following components in mass fractions: 5% to 20% of a deashing agent, 3% to 15% of an organic acid, 1% to 10% of a passivating agent, 0.5% to 10% of a builder, and 66% to 89.5% of water, the sum of the mass fractions of the components being 100%;

[0033] Wherein, the deashing agent includes liquid phosphoric acid compounds, liquid alcohol compounds and fluorine-containing compounds;

[0034] The fluorine-containing compound includes at least one of a liquid fluorine-containing compound and a fluorine-containing compound solution.

[0035] The present application cleans aluminum parts after local electroplating by introducing liquid phosphoric acid compounds, liquid alcohol compounds and fluorine-containing compounds into the dust removal agent. The fluoride in the fluorine-containing compound can react with the dust on the surface of the aluminum parts to effectively remove it without affecting the electroplated parts. At the same time, a dense oxide film can be formed on the surface of the parts to enhance the bonding strength between the parts and the subsequent casting layer.

[0036] The present invention is further described below in conjunction with the following examples. The protection scope of the present invention is not limited by the following examples.

[0037] Example 1

[0038] 2 volumes of polyphosphoric acid, 2 volumes of ethanol, 1 volume of ethylene glycol and 1 volume of phosphoric acid were mixed evenly, heated to 70° C. under stirring, kept warm for 30 minutes, and then 2 volumes of 30% hydrofluoric acid and 1 volume of fluoroboric acid were added to obtain deashing agent A.

[0039] Example 2

[0040] 1 volume of phosphoric acid, 1 volume of pyrophosphoric acid, 2 volumes of ethanol, 2 volumes of glycerol and 1 volume of benzyl alcohol were mixed evenly, heated to 100° C. under stirring, kept warm for 40 minutes, and then 2 volumes of 30% ammonium fluoride solution, 1 volume of 30% ammonium hydrogen fluoride solution and 1 volume of 20% sodium fluorosilicate solution were added to obtain deashing agent B.

[0041] Example 3

[0042] The cleaning solution provided in this embodiment includes the following components in mass fractions: 5% of deashing agent A, 5% of phytic acid, 5% of methanesulfonic acid, 6% of sodium persulfate and the balance of deionized water.

[0043] Example 4

[0044] The cleaning solution provided in this embodiment includes the following components in mass fractions: 5% of deashing agent B, 3% of oxalic acid, 5% of potassium thiocyanate, 8% of potassium chlorate and the balance of deionized water.

[0045] Example 5

[0046] The cleaning solution provided in this embodiment includes the following components in mass fractions: 8% of deashing agent A, 3% of glacial acetic acid, 1% of sodium bisulfate, 6% of potassium permanganate and the balance of deionized water.

[0047] Example 6

[0048] The cleaning solution provided in this embodiment includes the following components in mass fractions: 8% deashing agent B, 5% tartaric acid, 1% urea, 10% sodium hypochlorite and the balance deionized water.

[0049] Example 7

[0050] The cleaning solution provided in this embodiment includes the following components in mass fractions: 8% of deashing agent A, 8% of citric acid monohydrate, 2% of methanesulfonic acid, 6% of potassium dichromate and the balance of deionized water.

[0051] Example 8

[0052] The cleaning solution provided in this embodiment includes the following components in mass fractions: 8% of deashing agent B, 8% of lactic acid, 4% of methanesulfonic acid, 4% of sodium persulfate and the balance of deionized water.

[0053] Example 9

[0054] The cleaning solution provided in this embodiment includes the following components in mass fractions: 10% of deashing agent A, 6% of succinic acid, 3% of ethyl sulfonic acid, 4% of hydrogen peroxide and the balance of deionized water.

[0055] Example 10

[0056] The cleaning solution provided in this embodiment includes the following components in mass fractions: 10% of deashing agent B, 4% of ascorbic acid, 2% of aminosulfonic acid, 4% of chromic anhydride and the balance of deionized water.

[0057] Comparative Example 1

[0058] The difference between this comparative example and Example 3 is that an equal amount of deionized water is used to replace the deashing agent A, and the other components are the same as those in Example 3.

[0059] Comparative Example 2

[0060] The difference between this comparative example and Example 4 is that an equal amount of deionized water is used to replace the deashing agent B, and the other components are the same as those in Example 4.

[0061] Test Example 1

[0062] The cleaning solutions provided in Examples 3 to 10, Comparative Examples 1 and 2 were tested using aluminum-magnesium alloy, cast aluminum alloy and hard aluminum alloy respectively. The three aluminum materials were partially silver-plated and the insulating glue was removed. After polishing, they were soaked in the above cleaning solution for 2 minutes. After being taken out, they were washed with clean water to observe whether the brightness of the partially silver-plated aluminum parts was improved before and after cleaning, whether there was any metal dust or ash residue, and whether the silver-plated layer had any problems such as discoloration, bubbling, shedding, thinning, etc.

[0063] The non-electroplated part of the cleaned parts was cast with epoxy resin to make a 100*100 standard sample. The tensile properties between the epoxy resin layer and the aluminum substrate were tested using a tensile testing machine. The maximum load of shear failure of the sample was recorded as its bonding strength. The experimental results are summarized in Table 1.

[0064] Table 1 Cleaning test results of embodiments and comparative examples

[0065]

[0066]

[0067]

[0068] It can be seen from Table 1 that, compared with the comparative example, the cleaning liquid provided in the embodiment of the present invention can effectively remove oil stains, dust residues and surface dust on the surface of the non-electroplated part of the aluminum material after local electroplating, thereby improving the brightness of the aluminum surface without affecting the silver-plated surface; at the same time, it can improve the bonding strength between the non-electroplated part of the part and the cast insulating layer, with a bonding strength of up to 22.5 MPa.

[0069] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A cleaning liquid, characterized in that: The invention comprises the following components in mass fractions: 5% to 20% of a deashing agent, 3% to 15% of an organic acid, 1% to 10% of a passivating agent, 0.5% to 10% of a builder, and 66% to 89.5% of water, and the sum of the mass fractions of the components is 100%; Wherein, the deashing agent includes liquid phosphoric acid compounds, liquid alcohol compounds and fluorine-containing compounds; The fluorine-containing compound includes at least one of a liquid fluorine-containing compound and a fluorine-containing compound solution.

2. The cleaning liquid according to claim 1, characterized in that The liquid phosphoric acid compound is selected from at least one of polyphosphoric acid, phosphoric acid and pyrophosphoric acid; The liquid alcohol compound is selected from at least one of ethanol, ethylene glycol, glycerol and benzyl alcohol; The liquid fluorine-containing compound is fluoroboric acid; The fluorine-containing compound solution is selected from at least one of hydrofluoric acid, ammonium fluoride solution, ammonium bifluoride solution, fluoroboric acid and sodium fluorosilicate solution.

3. The cleaning solution according to claim 1, characterized in that The volume ratio of the liquid phosphoric acid compound, the liquid alcohol compound and the fluorine-containing compound is (1-5):(1-7):(1-6).

4. The cleaning liquid according to claim 1, characterized in that The organic acid is selected from at least one of tartaric acid, phytic acid, glacial acetic acid, citric acid monohydrate, lactic acid, succinic acid, ascorbic acid and oxalic acid.

5. The cleaning liquid according to claim 1, characterized in that The passivating agent is selected from at least one of sodium persulfate, potassium permanganate, potassium chlorate, sodium hypochlorite, potassium nitrate, potassium dichromate, hydrogen peroxide, chromic anhydride, and chromium sulfate.

6. The cleaning solution according to claim 1, characterized in that The builder is selected from at least one of methanesulfonic acid, ethylsulfonic acid, potassium thiocyanate, sodium bisulfate, aminosulfonic acid and urea.

7. A method for preparing a cleaning solution, characterized in that: include: The deashing agent, organic acid, passivating agent, builder and water are uniformly mixed to obtain a cleaning solution; Wherein, the deashing agent includes liquid phosphoric acid compounds, liquid alcohol compounds and fluorine-containing compounds; The fluorine-containing compound includes at least one of a liquid fluorine-containing compound and a fluorine-containing compound solution.

8. The preparation method according to claim 7, characterized in that: The deashing agent is prepared according to the following method: The liquid alcohol compound and the liquid phosphoric acid compound are mixed evenly, heated and kept warm, and then the fluorine-containing compound is added to obtain the deashing agent.

9. The preparation method according to claim 8, characterized in that: The heating temperature is 60-110° C. and the insulation time is 20-60 min.

10. Use of the cleaning liquid according to any one of claims 1 to 6 or the cleaning liquid prepared by the preparation method according to any one of claims 7 to 9 in cleaning aluminum parts after partial electroplating.

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