CN107022766B

CN107022766B - Metal surface cleaning agent, preparation method and metal surface cleaning method

Info

Publication number: CN107022766B
Application number: CN201610067195.0A
Authority: CN
Inventors: 韦家亮
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2016-01-29
Filing date: 2016-01-29
Publication date: 2020-03-20
Anticipated expiration: 2036-01-29
Also published as: CN107022766A

Abstract

The invention relates to a metal surface cleaning agent which is an aqueous solution containing a surfactant, an emulsifier, a complexing agent, carbonate and ferrate. The invention also provides a preparation method of the metal surface cleaning agent and a method for cleaning a metal substrate by adopting the cleaning agent. The cleaning agent provided by the invention can simultaneously realize oil removal and rust removal of the cleaning agent, and process steps are saved. Moreover, the rust on the surface of the base material is removed, and meanwhile, the metal surface is ensured not to be corroded.

Description

Metal surface cleaning agent, preparation method and metal surface cleaning method

Technical Field

The invention relates to a metal surface treatment technology, in particular to a metal surface cleaning agent and a preparation method thereof, and a metal surface cleaning method.

Background

The most simple and effective method is to coat a layer of metal or alloy with required performance on a substrate by an electrochemical method, namely electroplating and chemical plating, but various types of grease, mineral oil, fiber, sand, dust, hand sweat, fingerprints of operators, even rust spots oxidized by the metal, and the like are usually difficult to see by naked eyes on the surface of the metal in the processing process, but the dirt often affects the coating effect of electroplating or chemical plating, such as poor adhesion between ① coating and the surface of the substrate, frequent and air bubbles, poor surface appearance of ② coating, pits, roughness, spots, poor brightness, uneven brightness, and the like, ③ brittleness, pinholes, cracks and the like are increased, the corrosion resistance of the coating is reduced, ④ causes leakage plating, and the surface of the substrate is partially or even completely incapable of being coated.

Therefore, in order to avoid the above problems, the metal surface is cleaned effectively before being plated, including cleaning to remove oil, removing rust, and the like. Because the oil removal and the rust removal aim at different characteristics, different formulas are required to be used for performing the oil removal and the rust removal in a targeted manner. Making the cleaning process complicated; meanwhile, a chromium-containing compound, nitric acid, hydrofluoric acid, and the like are generally used in the rust remover, which causes a large environmental pollution.

Disclosure of Invention

In order to solve the problems, the invention provides a metal surface cleaning agent which is an aqueous solution containing a surfactant, an emulsifier, a complexing agent, carbonate and ferrate.

The acidity of the cleaning agent provided by the invention is between neutral and alkalescent, the content of each component in the formula is low, and the cleaning agent is environment-friendly. And rust on the surface of the alloy can be fully removed while oil removal and degreasing are performed, namely, two procedures of cleaning, oil removal and rust removal are combined together, so that the process flow is simplified, and waste liquid treatment and water consumption are reduced. Moreover, in the formula, ferrate is adopted to replace a chromium compound to remove rust on the surface of the alloy, so that the environmental protection performance of the alloy is further improved.

The invention also provides a preparation method of the metal surface cleaning agent, which comprises the steps of adding the surfactant, the emulsifier, the complexing agent, the carbonate and the ferrate into water, and stirring until the surfactant, the emulsifier, the complexing agent, the carbonate and the ferrate are dissolved.

A method for cleaning metal surface includes immersing the metal substrate in the cleaning agent for metal surface prepared by the present invention.

The metal surface cleaning agent provided by the invention is compounded by a plurality of components, and due to the interaction among the components, the cleaning agent can effectively remove oil and rust on the metal surface, thereby saving the process steps. Moreover, the cleaning agent can effectively remove oil and rust and simultaneously protect the surface of the base material from being corroded.

Detailed Description

The technical scheme of the invention relates to a metal surface cleaning agent which is an aqueous solution containing a surfactant, an emulsifier, a complexing agent, carbonate and ferrate.

Under the normal condition, the oil removal and the rust removal of the metal surface are carried out separately, and the technical process is complicated; in addition, a rust remover containing chromic anhydride is often adopted in the rust removing process, so that heavy metal pollution to the environment is caused. The inventor finds out through a large number of experiments that when ferrate ions are added into the cleaning agent, the cleaning agent can effectively remove rust on the metal surface while cleaning and removing oil. Meanwhile, as the metal surface is easy to corrode and is not acid and alkali resistant, ferrate ions can be combined with metal atoms on the metal surface in the rust removing process to form an oxide film on the metal surface to protect the surface, so that the metal is prevented from being corroded in the rust removing process. Preferably, the ferrate used in the present invention is one or more of potassium ferrate and sodium ferrate.

In the invention, the content of the surfactant is 1-12g/L, the content of the emulsifier is 0.1-3g/L, the content of the complexing agent is 1-10g/L, the content of the carbonate is 0.1-1g/L, and the content of the ferrate is 0.1-1 g/L.

In the present invention, the surfactant used has a good detergent action on various oils and fats, and may be an ionic and/or nonionic activator, which is a conventional choice in the art. The ionic surfactant used in the invention can be one or more of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, sodium dodecyl sulfate and fatty alcohol-polyoxyethylene ether sodium sulfate; the nonionic surfactant is one or more of triethanolamine oleate soap, alkylphenol polyoxyethylene, and nonylphenol polyoxyethylene. Preferably, the cleaning agent contains both the ionic surfactant and the nonionic surfactant, so that the oil removal efficiency can be further improved. More preferably, the amount ratio of the ionic surfactant to the nonionic surfactant is 0.1 to 1: 1. Through a large number of experiments, the inventor finds that the oil removal effect is best when the surfactant is a compound of triethanolamine oleate soap and sodium dodecyl sulfate.

In the invention, the adopted emulsifier is an emulsifier commonly used in the field, and specifically is one or more of sodium tripolyphosphate and sodium phosphate. The emulsifier can emulsify and disperse grease and improve the cleaning effect.

In the invention, the adopted complexing agent is a commonly used complexing agent in the field, and specifically is one or more of tartaric acid, disodium ethylene diamine tetraacetate and sodium citrate. The complexing agent can complex metal ions such as magnesium, aluminum and the like in the solution, so that the service life of the cleaning agent is prolonged.

According to the invention, the carbonate added into the cleaning agent can be subjected to esterification reaction with grease, so that the oil removal efficiency is further improved. The carbonate is commonly used in the art, and specifically can be sodium carbonate and/or sodium bicarbonate. When sodium bicarbonate is used, it is less likely to cause corrosion of the metal substrate surface because it is less alkaline than sodium carbonate.

Preferably, the cleaning agent contains nitrate ions, and can generate a synergistic effect with ferrate ions, so that the rust removing capability of the cleaning agent is further improved. Nitrate ions in the cleaning agent are derived from soluble nitrate, such as one or more of sodium nitrate, potassium nitrate and ferric nitrate. Preferably, the nitrate content is 0.1-5 g/L.

The cleaning agent provided by the invention is alkalescent. The cleaning solution requirement with higher requirement on the corrosivity of the metal can be met, and the metal cleaning and oil removing effect is particularly good. Preferably, the pH of the cleaning agent is between 8 and 10.

The invention also provides a method for cleaning the metal surface, which comprises the step of immersing the metal substrate in the metal surface cleaning agent obtained by the method. When the metal substrate is cleaned, the temperature of the cleaning agent is not too high, and the metal substrate is usually soaked for 1-5min at 20-40 ℃. In order to further improve the cleaning efficiency, the cleaning may be performed under ultrasonic conditions.

The cleaning agent provided by the invention can be applied to various metal base materials, and specifically at least one of aluminum materials, aluminum alloys, magnesium alloys and magnesium-aluminum alloys. When the paint is applied to magnesium alloy base materials, the oil and rust removing effect is particularly obvious.

In order to further explain the technical problems, technical solutions and advantages solved by the present invention, the present invention is described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

All the raw materials in the examples of the present invention are commercially available products unless otherwise specified.

Examples 1 to 7

1. Preparing a metal surface cleaning agent: adding surfactant, emulsifier, complexing agent, sodium bicarbonate and ferrate into deionized water. The metal surface cleaning agent A1-A7 is obtained according to the formula of the ancestral grave in the table 1, and the specific dosage of each group is shown in the table 1.

2. And (3) putting a magnesium alloy sample (the mark AZ 91D) of 2X 2cm into the cleaning agent in the step (1) for cleaning to obtain the cleaned magnesium alloy sample. The washing temperature was 40 ℃ and the washing time was 5 minutes.

Example 8

1. An aluminum alloy sample (No. 6061) of 2X 2cm was washed by the washing agent A1 obtained in example 1 to obtain a washed aluminum alloy sample. The washing temperature was 60 ℃ and the washing time was 5 minutes.

TABLE 1

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Comparative example 1

Cleaning a magnesium alloy sample by the method of embodiment 1 in the publication number CN103526265A, firstly using a magnesium alloy degreasing powder FG-02 type, and cleaning for 5 min; and cleaning for 1min by using FG-031 type magnesium alloy pickling agent to obtain a cleaned sample.

Comparative example 2

The formulation was the same as that of the surface cleaning agent A1 in example 1, except that potassium ferrate was not contained. And the magnesium alloy sample was cleaned according to the method of example 1.

Performance testing and results

And observing the oil and rust removing effects of the surface of the cleaned sample and the corrosion condition of the surface of the sample.

Oil removal effect: observing whether water drops are hung on the surface of the cleaned sample; the rust removing effect is as follows: observing whether the surface of the cleaned sample has rust and the size of the rust; corrosion conditions: and observing whether the surface of the cleaned sample has corrosion or not. The test results are shown in Table 2.

TABLE 2

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As can be seen from Table 2, the cleaning agent provided by the invention has good oil removal effect on metal, can quickly remove rust on the surface, does not corrode the surface of a substrate, has long service life and achieves excellent cleaning effect. Particularly, the oil and rust removing effect is more obvious when the cleaning agent is applied to magnesium alloy cleaning.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. It is not necessary or necessary to exhaustively enumerate all embodiments herein, and obvious variations or modifications can be introduced thereby while remaining within the scope of the invention as claimed.

Claims

1. The metal surface cleaning agent is characterized in that the cleaning agent is an aqueous solution containing a surfactant, an emulsifier, a complexing agent, nitrate, carbonate and ferrate; the metal base material is at least one of aluminum, aluminum alloy, magnesium alloy and magnesium-aluminum alloy; the content of the surfactant is 1-12g/L, the content of the emulsifier is 0.1-3g/L, the content of the complexing agent is 1-10g/L, the content of the carbonate is 0.1-1g/L, the content of the ferrate is 0.1-1g/L, and the content of the nitrate is 0.1-5 g/L; the pH value of the cleaning agent is 8-10.

2. The metal surface cleaning agent according to claim 1, wherein the nitrate is one or more of potassium nitrate, sodium nitrate and ferric nitrate.

3. The metal surface cleaning agent according to claim 1, wherein the surfactant contains an ionic surfactant and a nonionic surfactant; the dosage ratio of the ionic surfactant to the nonionic surfactant is 0.1-1: 1.

4. The metal surface cleaning agent according to claim 3, wherein the nonionic surfactant is one or more of triethanolamine oleate soap, alkylphenol ethoxylates and nonylphenol ethoxylates; the ionic surfactant is one or more of sodium dodecyl sulfate, sodium dodecyl sulfate and fatty alcohol-polyoxyethylene ether sodium sulfate.

5. The metal surface cleaning agent according to claim 3, wherein the surfactant contains triethanolamine oleate soap and sodium lauryl sulfate.

6. The metal surface cleaning agent according to claim 1, wherein the emulsifier is one or more of sodium tripolyphosphate and sodium phosphate; the complexing agent is one or more of tartaric acid, disodium ethylene diamine tetraacetate and sodium citrate; the carbonate is sodium carbonate and/or sodium bicarbonate; the ferrate is one or more of potassium ferrate and sodium ferrate.

7. The method for preparing a metal surface cleaning agent according to any one of claims 1 to 6, comprising adding a surfactant, an emulsifier, a complexing agent, a carbonate and ferrate to water, and stirring until dissolved.

8. A method for cleaning a metal surface, which comprises immersing a metal substrate in a cleaning agent, wherein the cleaning agent is the metal surface cleaning agent as claimed in any one of claims 1 to 6.

9. The method of claim 8, wherein the cleaning temperature is 20-40 ℃; the cleaning time is 1-5 min.