Copper material yellowing and brightening cleaning agent and use method thereof

Abstract

The invention provides a copper material yellowing and brightening cleaning agent. The copper material yellowing and brightening cleaning agent comprises the following raw material components in percentage by weight: 3-18% of a surfactant, 2-10% of a chelating agent, 1-10% of a nitrogen-containing polymer, 1-3% of polyaspartic acid, 1-4% of a polyhydroxy additive and the balance of water. The copper material yellowing and brightening cleaning agent can clean various dirt such as processing oil, dust, fingerprints and the like on the surface of a copper material, thoroughly remove a corroded heterochromatic layer and recover a bright surface, is safe and non-corrosive to a copper base material, does not influence the dimensional precision, and can be used for cleaning copper precision parts, and the cleaned workpiece is not easy to oxidize and discolor again. The copper material yellowing and brightening cleaning agent provided by the invention is safe to human bodies and the environment, wastewater treatment is easy, and the preparation process is simple and convenient.

Description

Technical Field

[0001] The present invention relates to the field of surface treatment, and in particular to a copper material yellowing and brightening cleaning agent and a use method thereof. Background Art

[0002] Copper and copper alloys have excellent thermal conductivity, electrical conductivity and mechanical properties. Copper precision parts are widely used in electronics, communications, aerospace, automobiles, precision instruments and other fields. For example, in the electronics field, copper precision parts are widely used in integrated circuits, printed circuit boards, solar panels and other equipment and devices. In the field of communications, copper precision parts are used to manufacture key components such as connectors and transmission lines. Since dimensional accuracy and surface cleanliness directly affect the performance and quality of copper precision parts, high-precision processing and high-cleanliness non-destructive cleaning of copper precision parts are particularly important.

[0003] Advanced technologies such as CNC machining and laser machining are widely used in the industry to obtain high-precision copper products. The surface of copper parts is inevitably contaminated by processing oil, dust, fingerprints and other dirt. Since copper has certain chemical activity, it is easily oxidized by oxygen and easily undergoes sulfidation reaction with more sulfur-containing substances. Therefore, the surface of copper precision parts often shows different degrees of yellowing and discoloration after processing and during placement, and the glossiness decreases or loses its gloss. In severe cases, the surface color is brown or black, which seriously affects the product quality. In view of this, copper cleaning agents not only need to clean various foreign dirt, but also need to remove the corrosion discoloration layer and restore the bright surface. They must not corrode the substrate of copper precision parts to avoid damaging the dimensional accuracy. In addition, the cleaning agent needs to have a corrosion inhibition and protection effect on the copper substrate, so that the cleaned copper precision parts can maintain a good state of brightness and no corrosion.

[0004] Existing copper cleaning agent technologies mostly use strong acid and strong alkali solutions. The strong corrosiveness of strong acid and strong alkali is used to remove the oxide scale on the copper surface, which can easily cause the copper substrate to be over-corroded, lose gloss and change in size. It cannot meet the requirements for cleaning copper precision parts, and there is a risk of corrosion and burns if the operator accidentally touches the skin. Some existing technologies use chemical polishing methods such as hydrogen peroxide to remove the oxidized heterochromatic layer on the copper surface and restore the bright surface, but it is highly corrosive to the substrate, the weight loss is too large, and it is easy to cause dimensional deviations in copper precision parts. The current copper material yellowing and brightening cleaning agents on the market generally have the problems of insufficient yellowing performance and inability to restore the bright surface, or insufficient corrosion inhibition performance, and the workpiece after cleaning is easy to oxidize and discolor again. Some existing technologies use toxic and harmful raw materials such as fluorine-containing substances, which seriously affect the health of operators; or use phosphorus-containing components, which increases the technical difficulty and treatment cost of subsequent wastewater treatment. Summary of the invention

[0005] The purpose of the present invention is to provide a copper material yellowing and brightening cleaning agent to address the deficiencies of the prior art. The cleaning agent is used to clean various dirt such as processing oil, dust, fingerprints, etc. on the surface of copper precision parts, can completely remove the corrosion discoloration layer, restore the bright surface, is safe for the copper substrate and does not affect the dimensional accuracy. The workpiece after cleaning is not easy to be oxidized and discolored again. The cleaning agent is safe for the human body and the environment, is easy to treat wastewater, and has a simple and convenient preparation process.

[0006] The technical solution adopted by the present invention is as follows: According to one aspect of the present invention, a copper material yellowing and brightening cleaning agent is provided, which comprises the following components in percentage by weight of raw materials: 3-18% surfactant, 2-10% chelating agent, 1-10% nitrogen-containing polymer, 1-3% polyaspartic acid, 1-4% polyhydroxy additive, and the balance is water.

[0007] Furthermore, the surfactant is at least one of fatty acid methyl ester ethoxylate, fatty acid diethanolamide, fatty alcohol polyoxyethylene ether sodium sulfate, and alkyl glycoside.

[0008] Furthermore, the chelating agent is at least one of gluconate, citrate, and glutamate diacetate.

[0009] Furthermore, the nitrogen-containing polymer is at least one of polyethyleneimine and chitosan.

[0010] Furthermore, the average molecular weight of the chitosan is 1000-5000.

[0011] Furthermore, the polyhydroxy additive is at least one of cyclodextrin and rhamnolipid.

[0012] Furthermore, the cyclodextrin is at least one of α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin.

[0013] Furthermore, the rhamnolipid is at least one of monorhamnolipid and disrhamnolipid.

[0014] The invention combines the wetting, penetration, emulsification and stripping effects of the surfactant with the chelating and dispersing effects of the chelating agent on the dirt on the surface of the copper parts, and has a good cleaning effect on dirt such as oil, dust, fingerprints and the like on the surface of the copper precision parts.

[0015] Since conventional chelating agents have limited binding force to copper ions and cuprous ions, they cannot completely remove the corrosion heterochromatic layer on the copper surface, resulting in a residual light-colored corrosion layer on the copper surface, and the surface is dull and has low gloss, and the bright surface cannot be restored. Therefore, nitrogen-containing polymers such as polyethyleneimine or chitosan with strong binding force to copper ions and cuprous ions are selected to completely remove the corrosion heterochromatic layer on the copper surface and restore the bright copper substrate. At the same time, due to the steric hindrance effect of the macromolecular structure, the copper corrosion of the nitrogen-containing polymer is significantly reduced compared with the corresponding monomer, thereby ensuring that the copper substrate is safe and non-corrosive under the premise of good copper de-yellowing and brightening performance, thereby ensuring dimensional accuracy and not affecting the performance and quality of copper precision parts.

[0016] If the copper parts after cleaning lack the protection of suitable corrosion inhibitors, the surface is easy to be oxidized, discolored and glossy again during the turnover between processes or short-term placement. Therefore, it is necessary to add copper corrosion inhibitors to the copper material yellowing brightening cleaning agent. Although the conventional copper corrosion inhibitor benzotriazole has a good copper corrosion inhibition effect, the copper yellowing brightening agent of the present invention is to ensure the dimensional accuracy of copper precision parts, and the selected cleaning scheme is non-corrosive to copper and has a mild effect on copper workpieces, resulting in benzotriazole seriously hindering the yellowing brightening effect of the cleaning agent. To solve this problem, the present invention proposes a copper corrosion inhibition scheme of polyaspartic acid and a polyhydroxy additive compound, which has good corrosion protection for the copper substrate without affecting the yellowing brightening effect. The copper parts after cleaning are not easy to be oxidized again and discolored, and the polyhydroxy additives cyclodextrin and rhamnolipid have a certain emulsification function on hydrophobic oil molecules, which can assist in oil removal and cleaning.

[0017] According to one aspect of the present invention, a method for using a copper material yellowing and brightening cleaning agent is provided, the steps comprising: 1. Take the above-prepared copper material yellowing brightening cleaning agent and dilute it with water to a dilution of 3-15% by mass; 2. Heat the diluted cleaning agent to 40-70°C and put it into the copper workpiece to be cleaned for ultrasonic cleaning.

[0018] Compared with the prior art, the present invention has the following advantages: 1. The present invention combines the wetting, penetration, emulsification and stripping effects of surfactants with the chelating and dispersing effects of chelating agents on the surface dirt of copper parts, and has a good cleaning effect on dirt such as oil, dust, fingerprints, etc. on the surface of copper precision parts. Nitrogen-containing polymers are used to completely remove the corrosion discoloration layer on the copper surface, and are safe and non-corrosive to the copper substrate, achieving the effect of yellowing and brightening, and does not affect the dimensional accuracy of copper precision parts.

[0019] 2. The present invention uses polyaspartic acid and polyhydroxy additives to compound, which has good corrosion inhibition and protection effect on copper substrates. Copper parts are not easy to oxidize and discolor again after cleaning, and do not affect the cleaning performance of the cleaning agent and the yellowing and brightening effect of copper.

[0020] 3. Some components of the present invention play multiple functions in the cleaning agent at the same time. Among them, polyaspartate and cyclodextrin or rhamnolipid provide corrosion protection for copper substrates. At the same time, polyaspartic acid has a certain chelating ability for metal ions such as calcium and magnesium, and has a washing effect on cleaning inorganic dust and dirt; cyclodextrin has a unique cone-shaped structure, and its hydrophobic inner cavity can contain hydrophobic oil molecules, and has a certain emulsification function, so it can assist in cleaning oil stains; rhamnolipid belongs to a class of biosurfactants, has a certain emulsification function, and can also assist in oil removal and cleaning. The present invention achieves the effect of reducing the types and amounts of formula raw material components by using the above-mentioned multifunctional components, and realizes the purpose of simplifying the production process and reducing costs.

[0021] 4. The present invention achieves good cleaning and brightening effects through the rational compounding of various components, does not use strong acids, strong bases, fluorine-containing substances and other substances that are harmful to the human body, and the formula components are all made of raw materials with good biodegradability, do not contain phosphorus, are easy to treat wastewater, and have a simple and convenient preparation process. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0023] The embodiment of the present invention provides a copper material yellowing removal and brightening cleaning agent, which includes the following components in percentage by weight of raw materials: 3-18% surfactant, 2-10% chelating agent, 1-10% nitrogen-containing polymer, 1-3% polyaspartic acid, 1-4% polyhydroxy additive, and the balance is water.

[0024] Furthermore, the surfactant is at least one of fatty acid methyl ester ethoxylate, fatty acid diethanolamide, fatty alcohol polyoxyethylene ether sodium sulfate, and alkyl glycoside.

[0025] Furthermore, the chelating agent is at least one of gluconate, citrate, and glutamate diacetate.

[0026] Furthermore, the nitrogen-containing polymer is at least one of polyethyleneimine and chitosan.

[0027] Further, the average molecular weight of the chitosan is 1000-5000. The molecular weight of chitosan has a certain influence on the performance of chitosan. When the molecular weight of chitosan is less than 1000, the steric hindrance effect of the chitosan molecule is insufficient, and there is a slight corrosion to the copper substrate. Although a bright copper surface can be obtained after cleaning, there are still hidden dangers to the dimensional accuracy of precision copper parts; and when the molecular weight of chitosan is greater than 5000, as the chitosan molecule increases, the water solubility gradually deteriorates, the solubility decreases, and the effect of yellowing and brightening cannot be fully exerted. Therefore, the present invention preferably uses chitosan with an average molecular weight of 1000-5000 to achieve a good yellowing and brightening effect and copper substrate safety.

[0028] Furthermore, the polyhydroxy additive is at least one of cyclodextrin and rhamnolipid.

[0029] Furthermore, the cyclodextrin is at least one of α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin.

[0030] Furthermore, the rhamnolipid is at least one of monorhamnolipid and disrhamnolipid. Example

[0031] A copper material yellowing and brightening cleaning agent is composed of the following components in percentage by mass: 8% fatty acid methyl ester ethoxylate, 4% alkyl glycoside, 4% sodium citrate, 4% polyethyleneimine, 2% polyaspartic acid, 2% beta-cyclodextrin, and the balance is water. Example

[0032] A copper material yellowing and brightening cleaning agent is composed of the following components in percentage by mass: 5% fatty acid diethanolamide, 3% fatty acid methyl ester ethoxylate, 3% sodium citrate, 3% sodium gluconate, 3% polyethyleneimine, 1.5% polyaspartic acid, 1% alpha-cyclodextrin, 2% monorhamnolipid, and the balance is water. Example

[0033] A copper material yellowing and brightening cleaning agent is composed of the following components in percentage by mass: 10% fatty acid diethanolamide, 5% sodium fatty alcohol polyoxyethylene ether sulfate, 3% tetrasodium glutamate diacetate, 8% chitosan (average molecular weight 4000), 3% polyaspartic acid, 3% disrhamnolipid, and the balance is water. Example

[0034] A copper material yellowing and brightening cleaning agent is composed of the following components in percentage by mass: 3% fatty acid methyl ester ethoxylate, 4% sodium citrate, 6% tetrasodium glutamate diacetate, 5% polyethyleneimine, 2.5% polyaspartic acid, 2% gamma-cyclodextrin, 2% disorhamnolipid, and the balance is water. Example

[0035] A copper material yellowing removal and brightening cleaning agent is composed of the following components in percentage by mass: 6% fatty acid methyl ester ethoxylate, 5% fatty acid diethanolamide, 6% alkyl glycoside, 1% sodium gluconate, 2% tetrasodium glutamate diacetate, 5% polyethyleneimine, 5% chitosan (average molecular weight 2000), 1% polyaspartic acid, 0.5% beta-cyclodextrin, 0.5% disrhamnolipid, and the balance is water. Example

[0036] A copper material yellowing and brightening cleaning agent is composed of the following components in percentage by mass: 5% fatty acid diethanolamide, 3% sodium gluconate, 4% sodium citrate, 3% polyethyleneimine, 4% chitosan (average molecular weight 3000), 1.5% polyaspartic acid, 3% monorhamnolipid, and the balance is water. Example

[0037] A copper material yellowing and brightening cleaning agent is composed of the following components in percentage by mass: 4% fatty acid methyl ester ethoxylate, 4% fatty acid diethanolamide, 1% fatty alcohol polyoxyethylene ether sodium sulfate, 3% sodium citrate, 4% chitosan (average molecular weight 3000), 2% polyaspartic acid, 3% gamma-cyclodextrin, and the balance is water. Example

[0038] A copper material yellowing and brightening cleaning agent is composed of the following components in percentage by mass: 7% fatty acid diethanolamide, 2% sodium fatty alcohol polyoxyethylene ether sulfate, 4% alkyl glycoside, 6% sodium gluconate, 4% polyethyleneimine, 2% chitosan (average molecular weight 5000), 3% polyaspartic acid, 1.5% alpha-cyclodextrin, 2% beta-cyclodextrin, and the balance is water. Example

[0039] A copper material yellowing and brightening cleaning agent is composed of the following components in percentage by mass: 4% fatty acid diethanolamide, 5% alkyl glycoside, 7% tetrasodium glutamate diacetate, 3% chitosan (average molecular weight 1000), 1.5% polyaspartic acid, 3% disrhamnolipid, and the balance is water. Example

[0040] A copper material yellowing and brightening cleaning agent is composed of the following components in percentage by mass: 6% fatty acid methyl ester ethoxylate, 5% fatty acid diethanolamide, 3% sodium citrate, 3% tetrasodium glutamate diacetate, 5% polyethyleneimine, 3% chitosan (average molecular weight 3000), 1% polyaspartic acid, 2% monorhamnolipid, and the balance is water. Example

[0041] A copper material yellowing removal and brightening cleaning agent is composed of the following components in percentage by mass: 3% fatty acid methyl ester ethoxylate, 4% fatty acid diethanolamide, 4% fatty alcohol polyoxyethylene ether sodium sulfate, 2% tetrasodium glutamate diacetate, 3% polyethyleneimine, 3% polyaspartic acid, 2% α-cyclodextrin, 1% γ-cyclodextrin, and the balance is water. Example

[0042] A copper material yellowing and brightening cleaning agent is composed of the following components in percentage by mass: 12% fatty acid diethanolamide, 2% sodium gluconate, 5% sodium citrate, 7% chitosan (average molecular weight 3000), 2% polyaspartic acid, 0.5% monorhamnolipid, 2.5% disrhamnolipid, and the balance is water.

[0043] Comparative Example 1 Compared with Example 1, the only difference is that no nitrogen-containing polymer is added, and the raw materials specifically include the following weight percentages: fatty acid methyl ester ethoxylate 8%, alkyl glycoside 4%, sodium citrate 4%, polyaspartic acid 2%, β-cyclodextrin 2%, and the balance is water.

[0044] Comparative Example 2 Compared with Example 1, the only difference is that no polyaspartic acid is added, and the raw materials specifically include the following weight percentages: fatty acid methyl ester ethoxylate 8%, alkyl glycoside 4%, sodium citrate 4%, polyethyleneimine 4%, β-cyclodextrin 2%, and the balance is water.

[0045] Comparative Example 3 Compared with Example 1, the only difference is that no polyhydroxy additive is added, and specifically includes the following raw materials in weight percentage: Fatty acid methyl ester ethoxylate 8%, alkyl glycoside 4%, sodium citrate 4%, polyethyleneimine 4%, polyaspartic acid 2%, the balance is water.

[0046] Comparative Example 4 Compared with Example 1, the only difference is that no polyaspartic acid and polyhydroxy additives are added, and the raw materials specifically include the following weight percentages: 8% fatty acid methyl ester ethoxylate, 4% alkyl glycoside, 4% sodium citrate, 4% polyethyleneimine, and the balance is water.

[0047] Comparative Example 5 A cleaning agent is composed of the following components in percentage by mass: 25% sulfuric acid, 8% fatty acid methyl ester ethoxylate, 4% alkyl glycoside, and the balance is water.

[0048] Comparative Example 6 A cleaning agent is composed of the following components in percentage by mass: 15% sulfuric acid, 5% hydrogen peroxide, 8% fatty acid methyl ester ethoxylate, 4% alkyl glycoside, and the balance is water.

[0049] Test Example 1 The cleaning and yellowing brightening performance of the copper material cleaning agents obtained in Examples 1-12 and Comparative Examples 1-6 were examined. A copper workpiece placed for 24 hours after CNC machining was cleaned. The workpiece was stained with cutting oil and the surface was dark yellow-brown. The workpiece was immersed in a 10% dilution of the cleaning agent and ultrasonically cleaned at 50°C for 3 minutes. After rinsing and drying, the cleaning results were examined. The copper appearance was placed at room temperature for 15 days to examine whether it changed color. The results are shown in Table 1: Table 1 Comparison of cleaning performance results As can be seen from Table 1, Examples 1 to 12 have good degreasing and cleaning effects, and can completely remove the corrosion discoloration layer on the surface of the copper part, restore the bright surface, and the cleaned workpiece is not easy to oxidize and discolor again. By comparing the data of Example 1 with the comparative examples, it can be seen that in Comparative Example 1, no nitrogen-containing polymer is added, and the copper corrosion heterochromic layer cannot be completely removed, and there is a light yellow residue, the surface gloss is low, and a bright surface cannot be obtained; in Comparative Example 2, no polyaspartic acid is added, and only a polyhydroxy additive is used for corrosion inhibition, the copper corrosion inhibition time is short, and the cleaned copper parts are oxidized again after being placed for 4 days; in Comparative Examples 3 and 4, no polyhydroxy additive is added, the degreasing effect is slightly deteriorated, and the copper corrosion inhibition time is short; Comparative Example 5 is a strong acid system, which relies on strong corrosiveness to completely remove the copper surface oxidation heterochromic layer, but the substrate is over-corroded, causing the substrate to be fogged, the gloss is low, the copper corrosion inhibition time is very short, and the copper parts are oxidized a few hours after washing; Comparative Example 6 is a strong acid plus hydrogen peroxide polishing system, which can completely remove the copper surface oxidation heterochromic layer and make the surface bright through polishing, but the copper corrosion inhibition time is very short, and the copper parts are oxidized a few hours after washing.

[0050] Test Example 2 The copper substrate safety test was conducted by taking a clean and corrosion-free copper test piece and soaking it in a 10% dilution of the copper cleaning agent of Examples 1-12 and Comparative Examples 1-6, respectively, at a constant temperature of 50°C for 1 hour, observing the appearance of the copper test piece and comparing the weight loss of the copper test piece to measure the safety of the cleaning agent on the copper substrate. The results are shown in Table 2: Table 2 Copper substrate safety test results From the results in Table 2, it can be seen that the copper yellowing and brightening cleaning agent provided by the present invention is safe and non-corrosive to the copper substrate; the weight loss of comparative examples 2-4 without adding the corrosion inhibitor polyaspartic acid and / or polyhydroxy additive is very small, and it is also relatively safe for the copper substrate; while the copper weight loss of comparative examples 5 and 6 of the strong acid system is extremely large, and it is highly corrosive to the copper substrate, which can easily cause dimensional deviation and is not suitable for cleaning copper precision parts.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A copper material yellowing and brightening cleaning agent, characterized in that: The raw materials include the following components by weight percentage: 3-18% surfactant, 2-10% chelating agent, 1-10% nitrogen-containing polymer, 1-3% polyaspartic acid, 1-4% polyhydroxy additive, and the balance is water.

2. The copper material yellowing and brightening cleaning agent according to claim 1, characterized in that: The surfactant is at least one of fatty acid methyl ester ethoxylate, fatty acid diethanolamide, fatty alcohol polyoxyethylene ether sodium sulfate, and alkyl glycoside.

3. The copper material yellowing and brightening cleaning agent according to claim 1, characterized in that: The chelating agent is at least one of gluconate, citrate and glutamate diacetate.

4. The copper material yellowing and brightening cleaning agent according to claim 1, characterized in that: The nitrogen-containing polymer is at least one of polyethyleneimine and chitosan.

5. The copper material yellowing and brightening cleaning agent according to claim 4, characterized in that: The average molecular weight of the chitosan is 1000-5000.

6. The copper material yellowing and brightening cleaning agent according to claim 1, characterized in that: The polyhydroxy additive is at least one of cyclodextrin and rhamnolipid.

7. The copper material yellowing and brightening cleaning agent according to claim 6, characterized in that: The cyclodextrin is at least one of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin.

8. The copper material yellowing and brightening cleaning agent according to claim 6, characterized in that: The rhamnolipid is at least one of monorhamnolipid and disrhamnolipid.

9. A method for using the copper material yellowing and brightening cleaning agent according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Take the above-prepared copper material yellowing brightening cleaning agent and dilute it with water to a dilution solution with a mass percentage of 3-15%; (2) Heat the diluted cleaning agent to 40-70°C and place it into the copper workpiece to be cleaned for ultrasonic cleaning.